A treatment system for propylene oxide production process depropylene tower discharge liquid

Abstract

The utility model discloses a processing system for the effluent of a depropylene tower in a propylene oxide production process. The processing system comprises a depropylene tower, a scrubber I, and a separation membrane system I or an electric desalination system I. The processing system is used to process the effluent of the depropylene tower to purify, extract and recover the value of useful materials containing molybdenum elements therein.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical process treatment, and specifically relates to a treatment system for a propylene oxide production process's effluent from a depropylene tower. Background Art

[0002] Propylene oxide is also called PO. There are many production processes of PO in the prior art, such as POSM co-production process, HPPO process and so on.

[0003] One of the PO production processes (POSM co-production process) is to use propylene and EBHP to undergo liquid phase epoxidation reaction in the presence of a molybdenum catalyst (such as ammonium dimolybdate) in an epoxidation reaction system (epoxidation reactor) to produce propylene oxide (PO) and MBA, propylene + EBHP (under molybdenum catalyst) → PO + MBA.

[0004] The materials in the epoxidation reactor enter the depropanization tower (high-pressure depropanization tower, the purpose is to remove propylene) according to the process flow, that is, the materials in the epoxidation reactor enter the depropanization tower (high-pressure depropanization tower) for treatment, remove and extract propylene (this propylene is recycled to the epoxidation reactor and new propylene is added, and is used again to react with EBHP to generate PO+MBA). The effluent (bottom liquid, containing PO, MBA, propylene, etc.) of the depropanization tower (high-pressure depropanizer) also contains a molybdenum-based catalyst. If there is a device or system that can process the effluent (bottom liquid) of the depropanization tower (high-pressure depropanizer), the molybdenum-containing compounds therein can be extracted for recovery, and the economic value of the recovered molybdenum-containing compounds can create great value and contribute benefits to the enterprise. Utility Model Content

[0005] The utility model aims to provide a processing system for the effluent from a depropanization tower in a propylene oxide production process. The processing system is used to process the effluent from the depropanization tower (the bottom liquid of the high-pressure depropanization tower, a compound containing the molybdenum element), so as to purify, extract and recover valuable materials (substances containing the molybdenum element), create value and save the operating costs of the enterprise.

[0006] A treatment system for a propylene oxide production process for a depropanolating tower effluent, the treatment system comprising: a depropanolating tower, a scrubber I, and a separation membrane system I or an electric desalination system I;

[0007] The outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber I, and the water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I; or the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber I, and the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I,

[0008] The upstream of the depropanation tower (high-pressure depropanation tower) is an epoxidation reaction system (epoxidation reactor). In the epoxidation reaction system (epoxidation reactor), propylene and EBHP undergo liquid-phase epoxidation reaction in the presence of a molybdenum-based catalyst (e.g., ammonium dimolybdate) to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA, that is, the epoxidation reaction system (epoxidation reactor) refers to a device that produces PO through a chemical reaction. Therefore, the material components discharged from the epoxidation reaction system (epoxidation reactor) to the depropanation tower (high-pressure depropanation tower) are mainly PO, MBA, unreacted propylene (needs to be removed), etc., and molybdenum-containing inorganic substances (as catalysts for the epoxidation reactor. The purpose of the design of the utility model is to Recover this part of the molybdenum-containing inorganic matter), the materials in the epoxidation reaction system (epoxidation reactor) enter the de-propanization tower (high-pressure de-propanization tower) to remove a part of propylene, and then the de-propanization tower discharge liquid (tower bottom liquid, which contains molybdenum inorganic matter, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic matter) is washed by the scrubber I, and the washing product is divided into an oil phase and an aqueous phase. The aqueous phase (regardless of its pH value, as long as it is insoluble in oil and separated, it is called the aqueous phase) mainly contains ions soluble in water (inorganic matter containing molybdenum elements, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic matter) and organic matter dissolved in the aqueous phase, which is then separated by the separation membrane system I; or separated by the electric desalination system I.

[0009] Based on the above processing system, preferably,

[0010] The water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, and the brine outlet with high molybdenum content of the separation membrane system I is connected to the inlet of the epoxidation reaction system or the recovery tank; the water phase of the scrubber I is treated by the separation membrane system I to obtain two streams of water, the brine with high molybdenum content and the brine with low molybdenum content, which is equivalent to separating the water phase of the scrubber I, and the brine with high molybdenum content and the brine with low molybdenum content are compared with each other. In comparison, the content of molybdenum in the brine with high molybdenum content is higher than the content of molybdenum in the brine with low molybdenum content;

[0011] After separation treatment by the separation membrane system I, two products, brine with high molybdenum content and brine with low molybdenum content, are obtained. The concentrations of organic components in the brine with high molybdenum content and the brine with low molybdenum content are relatively similar, but the molybdenum content is quite different, so it is equivalent to using the separation membrane system I to separate the molybdenum element and the organic matter. Since the purpose of the utility model is to recover inorganic matter containing molybdenum, the scheme design is mainly to recover the brine with high molybdenum content (and it is hoped that the organic content is as low as possible, organic matter is an impurity). Since the flow rate of the brine with high molybdenum content is obviously much lower than the water phase flow rate of the scrubber I (that is, the influent treatment water volume of the separation membrane system I), the brine with high molybdenum content obtained by separation treatment by the separation membrane system I is Compared with the water phase of scrubber I, the inorganic components containing molybdenum in the water are obviously concentrated and increased (i.e., the ratio of the total amount of molybdenum to the total amount of organic matter is increased), which is equivalent to separating the organic matter and the inorganic matter containing molybdenum through the separation membrane system I, and obtaining the inorganic matter rich in concentrated molybdenum (wherein the ratio of organic matter is reduced). The brine with high molybdenum content can be recycled and reused in the epoxidation reaction system (because the ratio of organic impurities is reduced), which is equivalent to recycling the molybdenum catalyst, and can also be recycled as a product into the recovery tank; the organic components and concentrations in the brine with low molybdenum content are similar to those of the water phase of scrubber I, but the molybdenum concentration is greatly reduced, so the ratio of the total amount of molybdenum to the total amount of organic matter is greatly reduced;

[0012] Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, and the brine outlet with high molybdenum content of the electric desalination system I is connected to the inlet of the epoxidation reaction system or the recovery tank; the water phase of the scrubber I is treated by the electric desalination system I to obtain two streams of water, the brine with high molybdenum content and the brine with low molybdenum content, which is equivalent to separating the water phase of the scrubber I, and the brine with high molybdenum content and the brine with low molybdenum content are compared with each other. In comparison, the content of molybdenum in the brine with high molybdenum content is higher than the content of molybdenum in the brine with low molybdenum content;

[0013] After being separated and treated by the electric desalination system I, two products, brine with high molybdenum content and brine with low molybdenum content, are obtained. The concentrations of organic components in the brine with high molybdenum content and the brine with low molybdenum content are relatively similar, but the molybdenum content is quite different, so it is equivalent to using the electric desalination system I to separate the molybdenum element and the organic matter. Since the purpose of the utility model is to recover inorganic matter containing molybdenum, the scheme design is mainly to recover the brine with high molybdenum content (and it is hoped that the organic content therein is as low as possible, as organic matter is an impurity). Since the flow rate of the brine with high molybdenum content is obviously much lower than the water phase flow rate of the scrubber I (i.e., the influent treatment water volume of the electric desalination system I), the brine with high molybdenum content obtained by separation and treatment by the electric desalination system I is Compared with the water phase of the scrubber I, it is obvious that the inorganic components containing molybdenum are concentrated and increased (i.e., the ratio of the total amount of molybdenum to the total amount of organic matter is increased), which is equivalent to separating the organic matter and the inorganic matter containing molybdenum through the treatment of the electric desalination system I, and obtaining the inorganic matter rich in concentrated molybdenum (wherein the proportion of organic matter is reduced). The brine with high molybdenum content can be recycled and reused in the epoxidation reaction system (because the proportion of organic impurities is reduced), which is equivalent to recycling the molybdenum catalyst, and can also be recycled as a product into the recovery tank; the organic components and concentrations in the brine with low molybdenum content are similar to those of the water phase of the scrubber I, but the molybdenum concentration is greatly reduced, so the ratio of the total amount of molybdenum to the total amount of organic matter is greatly reduced;

[0014] The epoxidation reaction system, such as the epoxidation reactor, refers to the equipment for producing PO by chemical reaction, i.e., the front-end process of the depropanation tower (according to the process flow, the materials in the epoxidation reaction system (epoxidation reactor) will enter the depropanation tower (high-pressure depropanation tower) again). In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo liquid-phase epoxidation reaction to produce propylene oxide (PO) and MBA, propylene+EBHP→PO+MBA.

[0015] Based on the above treatment system, preferably, the epoxidation reaction system refers to an epoxidation reactor, which refers to an epoxidation reactor in which propylene and EBHP undergo a chemical reaction. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene+EBHP→PO+MBA.

[0016] Based on the above treatment system, preferably, the epoxidation reaction system (epoxidation reactor) adds a molybdenum-containing catalyst, and the molybdenum-containing catalyst is preferably ammonium dimolybdate, which is an inorganic substance.

[0017] Based on the above treatment system, preferably, the epoxidation reaction system (epoxidation reactor) adds a molybdenum-containing catalyst, and the molybdenum-containing catalyst is preferably ammonium dimolybdate (inorganic substance). The molybdenum-containing catalyst (ammonium dimolybdate) is first mixed with isooctyl alcohol and then added to the epoxidation reaction system (epoxidation reactor).

[0018] Based on the above treatment system, preferably, the epoxidation reaction system (epoxidation reactor) adds a molybdenum-containing catalyst, and the molybdenum-containing catalyst is preferably ammonium dimolybdate (inorganic substance). The molybdenum-containing catalyst (ammonium dimolybdate) is first mixed with isooctyl alcohol (mixing ratio, for example, molybdenum catalyst (ammonium dimolybdate): isooctyl alcohol = 3:11), and then added to the epoxidation reaction system (epoxidation reactor).

[0019] Based on the above treatment system, preferably, the epoxidation reaction system (epoxidation reactor) adds a molybdenum-containing catalyst, and the molybdenum-containing catalyst is preferably ammonium dimolybdate (inorganic substance). The molybdenum-containing catalyst (ammonium dimolybdate) is first mixed with isooctyl alcohol and ethylbenzene, and then added to the epoxidation reaction system (epoxidation reactor).

[0020] Based on the above treatment system, preferably, the epoxidation reaction system (epoxidation reactor) adds a molybdenum-containing catalyst, and the molybdenum-containing catalyst is preferably ammonium dimolybdate (inorganic substance). The molybdenum-containing catalyst (ammonium dimolybdate) is first mixed with isooctyl alcohol and ethylbenzene (mixing ratio, for example, molybdenum catalyst (ammonium dimolybdate): isooctyl alcohol: ethylbenzene = 3:11:10), and then added to the epoxidation reaction system (epoxidation reactor).

[0021] Based on the above treatment system, preferably, a separation membrane system II, an electric desalination system II, a separation membrane system III or an electric desalination system III is further provided.

[0022] The water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, the brine outlet with high molybdenum content of the separation membrane system I is connected to the water inlet of the electric desalination system II, and the brine outlet with high molybdenum content of the electric desalination system II is connected to the inlet of the epoxidation reaction system or the recovery tank, that is, the brine with high molybdenum content obtained by the separation membrane system I (which is rich in concentrated inorganic matter containing molybdenum, but organic matter is not significantly concentrated) is processed again by the electric desalination system II (whose principle is the same as that of the electric desalination system I), and inorganic matter (referring to inorganic matter containing molybdenum) and organic matter are separated again, that is, the inorganic matter containing molybdenum is concentrated again, and the organic matter is still not significantly concentrated, which is conducive to further increasing the proportion of inorganic matter containing molybdenum in the brine with high molybdenum content of the electric desalination system II (that is, the ratio of the total amount of molybdenum: the total amount of organic matter is increased);

[0023] Or the water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, the brine outlet with high molybdenum content of the separation membrane system I is connected to the water inlet of the separation membrane system II, and the brine outlet with high molybdenum content of the separation membrane system II is connected to the inlet of the epoxidation reaction system or the recovery tank, that is, the brine with high molybdenum content obtained by the separation membrane system I (which is rich in concentrated inorganic molybdenum-containing matter, but organic matter is not significantly concentrated) is processed again by the separation membrane system II (whose principle is the same as that of the separation membrane system I), and the inorganic molybdenum-containing matter and organic matter are separated again, that is, the inorganic molybdenum-containing matter is concentrated again, and the organic matter is still not significantly concentrated, which is conducive to further increasing the proportion of inorganic molybdenum-containing matter in the brine with high molybdenum content of the separation membrane system II (that is, the ratio of the total amount of molybdenum: the total amount of organic matter is increased);

[0024] Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, the brine outlet with high molybdenum content of the electric desalination system I is connected to the water inlet of the separation membrane system III, and the brine outlet with high molybdenum content of the separation membrane system III is connected to the inlet of the epoxidation reaction system or the recovery tank, that is, the brine with high molybdenum content obtained by the treatment of the electric desalination system I (which is rich in concentrated inorganic matter containing molybdenum, but organic matter is not significantly concentrated) is processed again by the separation membrane system III (whose principle is the same as that of the separation membrane system I), and the inorganic matter containing molybdenum and organic matter are separated again, that is, the inorganic matter containing molybdenum is concentrated again, and the organic matter is still not significantly concentrated, which is conducive to further increasing the proportion of inorganic matter containing molybdenum in the brine with high molybdenum content of the separation membrane system III (that is, the ratio of the total amount of molybdenum: the total amount of organic matter is increased);

[0025] Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, the brine outlet with high molybdenum content of the electric desalination system I is connected to the water inlet of the electric desalination system III, and the brine outlet with high molybdenum content of the electric desalination system III is connected to the inlet of the epoxidation reaction system or the recovery tank, that is, the brine with high molybdenum content obtained by treatment of the electric desalination system I (which is rich in concentrated inorganic matter containing molybdenum, but organic matter is not concentrated) is processed again by the electric desalination system III (whose principle is the same as that of the electric desalination system I) to separate inorganic matter and organic matter containing molybdenum again, that is, the inorganic matter containing molybdenum is concentrated again, and the organic matter is still not obviously concentrated, which is conducive to further increasing the proportion of inorganic matter containing molybdenum in the brine with high molybdenum content of the electric desalination system III (that is, the ratio of the total amount of molybdenum: the total amount of organic matter is increased).

[0026] Based on the above treatment system, preferably, an oil removal device is further provided between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oil removal device is further provided between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oxidative elimination device is further provided between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidative elimination device is further provided between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oil removal device and an oxidative elimination device are further provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oil removal device and an oxidative elimination device are further provided in sequence between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oxidative elimination device and an oil removal device are further provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidative elimination device and an oil removal device are further provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidative elimination device and an oil removal device are further provided in sequence between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I;

[0027] The purpose of providing the oxidation elimination device is to remove the oxidation of the solution, that is, the oxidation in the influent, to avoid the harm of the oxidation to the subsequent system;

[0028] The oil removal device is provided because the water phase of the scrubber I still contains a certain oil concentration, and the oil concentration needs to be removed as much as possible to facilitate the stable operation of the separation membrane system I or the electric desalination system I and avoid blockage of the separation membrane system I or the electric desalination system I.

[0029] Based on the above treatment system, preferably, the device for eliminating oxidizing agents includes adding a reducing agent or adsorbing oxidizing agents on a fixed bed or removing oxidizing agents by reacting a fixed bed.

[0030] Based on the above treatment system, preferably, the added reducing agent includes sodium bisulfite, sodium thiosulfate, sodium sulfite and other reducing agents.

[0031] Based on the above treatment system, preferably, the oil removal device includes an oil-water stratification device (stratifying oil and water in a static manner, removing the oil concentration in the water phase, and reducing the oil concentration in the water phase), a rotating stratification device (that is, compared with the oil-water stratification device, the flow path length is increased by rotation, which is more conducive to oil-water separation, removing the oil concentration in the water phase, and reducing the oil concentration in the water phase), a flotation device (using bubbles or tiny bubbles to remove the oil to the surface of the water phase to further remove the oil, removing the oil concentration in the water phase, and reducing the oil concentration in the water phase), an oil separator (that is, using the oil separator to separate the oil in the water phase The invention further comprises at least one of the following: a water phase separation device (i.e., using a scraper to scrape off the oil in the water phase to remove the oil concentration in the water phase, and the obtained water phase has a lower oil concentration); an oil scraping device (i.e., using a scraper to scrape off the oil in the water phase to remove the oil concentration in the water phase, and the obtained water phase has a lower oil concentration); an oil removal membrane device (i.e., using an oil removal membrane method, such as an ultrafiltration membrane, to intercept the oil and separate it from water, remove the oil concentration in the water phase, and the obtained water phase has a lower oil concentration); an air-blowing oil-removing volatilization device (i.e., using air-blowing to facilitate the volatilization of the oil phase, remove the oil, remove the oil concentration in the water phase, and the obtained water phase has a lower oil concentration); or an oil dissolving device (i.e., adding chemicals to dissolve the oil).

[0032] Based on the above processing system, preferably, the oil separator is a tank with a vertical partition inside the tank, the liquid inlet and the drain outlet are on the same side of the vertical partition, and the oil outlet is on the other side of the vertical partition. The oil with low density in the tank overflows and submerges the upper edge of the vertical partition to one side of the oil outlet, and the water with high density is intercepted by the vertical partition and discharged from the drain outlet, thereby realizing oil-water separation.

[0033] Based on the above treatment system, preferably, the oil dissolving device is also connected to an alkali adding pipeline or an emulsifier pipeline, that is, the oil is dissolved with alkali solution or emulsifier.

[0034] Based on the above treatment system, preferably, between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system II and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system III and the inlet of the epoxidation reaction system, the separation membrane A bipolar membrane device is provided between the outlet of the brine with high molybdenum content of system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electrical desalination system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electrical desalination system II and the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the electrical desalination system III and the inlet of the recovery tank; or an evaporator III and a solid-liquid separation device III; or an ammonia addition device II; or an incineration device;

[0035] The brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the bipolar membrane device, and the acid outlet of the bipolar membrane device is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank. The bipolar membrane device is a device that converts salt into acid and alkali by using electrical energy, and has an acid outlet, an alkali outlet, and a water inlet of the bipolar membrane device. The bipolar membrane device is a device for electrolyzing water into hydrogen ions and hydroxide ions by using a bipolar membrane under the action of a direct current electric field. The bipolar membrane, the cation membrane, and the anion membrane are cleverly combined to convert concentrated brine into acid and alkali, convert cations in the brine into hydroxides corresponding to the cations, i.e., alkalis; convert anions in the brine into hydrides corresponding to the anions, i.e., acids; and at the same time, after the anions and cations in the concentrated brine are converted into corresponding alkalis and acids and the concentration is reduced, it is called diluted brine; the bipolar membrane device is used to convert molybdenum-containing salts into molybdenum-containing acids, which are reused in the epoxidation reaction system or recovered in the recovery tank;

[0036] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the evaporator I, the outlet of the evaporator I is connected to the inlet of the solid-liquid separation device I, the solid outlet of the solid-liquid separation device I is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank, the bipolar membrane device is a device that uses electrical energy to convert salt into acid and alkali, and it has an acid outlet, an alkali outlet, and a brine outlet, and the bipolar membrane device is in a DC electric field Under the action of the bipolar membrane, water is electrolyzed into hydrogen ions and hydroxide ions by using the bipolar membrane. By the ingenious combination of the bipolar membrane, the cation membrane and the anion membrane, the concentrated brine can be converted into acid and base, the cations in the brine are converted into the hydroxide corresponding to the cation, that is, the base; the anions in the brine are converted into the hydride corresponding to the anion, that is, the acid; at the same time, after the anions and cations in the concentrated brine are converted into the corresponding bases and acids and the concentration is reduced, it is called light brine; the molybdenum-containing salt is converted into the acid containing the molybdenum element by using the bipolar membrane device, and then the molybdenum-containing acid is treated by using the evaporator I and the solid-liquid separation device I to obtain a solid, which is then reused in the epoxidation reaction system or recovered in the recovery tank. At the same time, a cooler can be set between the evaporator I and the solid-liquid separation device I to reduce the temperature to further reduce the solubility of the acid containing the molybdenum element, which is conducive to the precipitation of the solid;

[0037] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the ammonia addition device I, and the water outlet of the ammonia addition device I is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank. The bipolar membrane device is a device that uses electrical energy to convert salt into acid and alkali, and has an acid outlet, an alkali outlet, and a water outlet. outlet, and a salt water outlet. The bipolar membrane device uses a bipolar membrane to electrolyze water into hydrogen ions and hydroxide ions under the action of a direct current electric field. The bipolar membrane, the cation membrane, and the anion membrane are cleverly combined to convert concentrated salt water into acid and alkali, convert cations in the salt water into hydroxides corresponding to the cations, i.e., alkalis; convert anions in the salt water into hydrides corresponding to the anions, i.e., acids; and at the same time, after the anions and cations in the concentrated salt water are converted into corresponding alkalis and acids and the concentration is reduced, it is called salt water; the bipolar membrane device is used to convert molybdenum-containing salts into acids containing molybdenum elements, and then ammonia water is added (neutralization reaction) to convert them into ammonium salts containing molybdenum elements, and then they are reused in the epoxidation reaction system or recovered in the recovery tank;

[0038] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the ammonia addition device I, the water outlet of the ammonia addition device I is connected to the water inlet of the evaporator II, the outlet of the evaporator II is connected to the inlet of the solid-liquid separation device II, the solid outlet of the solid-liquid separation device II is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank, the bipolar membrane device is a device that uses electrical energy to convert salt into acid and alkali, and it has an acid outlet, an alkali outlet, and a brine outlet, and ... Under the action of the field, water is electrolyzed into hydrogen ions and hydroxide ions by using a bipolar membrane. By cleverly combining the bipolar membrane with the cation membrane and the anion membrane, concentrated brine can be converted into acid and alkali, and the cations in the brine are converted into the hydroxide corresponding to the cation, that is, the alkali; the anions in the brine are converted into the hydride corresponding to the anion, that is, the acid; at the same time, after the anions and cations in the concentrated brine are converted into the corresponding alkali and acid and the concentration is reduced, it is called light brine; the molybdenum-containing salt is converted into the acid containing the molybdenum element by using the bipolar membrane device, and then ammonia water is added (neutralization reaction) to convert it into an ammonium salt containing the molybdenum element, and then it is processed by the evaporator II and the solid-liquid separation device II to obtain a solid ammonium salt containing the molybdenum element and reused in the epoxidation reaction system, or recovered into the recovery tank. At the same time, a cooler can be set between the evaporator II and the solid-liquid separation device II to reduce the temperature to further reduce the solubility of the ammonium salt containing the molybdenum element, which is conducive to solid precipitation;

[0039] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the evaporator III, the outlet of the evaporator III is connected to the inlet of the solid-liquid separation device III, and the solid outlet of the solid-liquid separation device III is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank, that is, the solid salt containing molybdenum obtained by treatment by the evaporator III and the solid-liquid separation device III is reused in the epoxidation reaction system or recovered into the recovery tank, and at the same time, a cooler can be arranged between the evaporator III and the solid-liquid separation device III to reduce the temperature to further reduce the solubility of the salt containing molybdenum, which is conducive to solid precipitation;

[0040] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the ammonia addition device II, and the water outlet of the ammonia addition device II is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank: the purpose of adding ammonia water is to convert it into ammonium salt containing molybdenum element, which is then reused in the epoxidation reaction system or recovered in the recovery tank;

[0041] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III, or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the ammonia addition device II, the water outlet of the ammonia addition device II is connected to the water inlet of the evaporator IV, the outlet of the evaporator IV is connected to the inlet of the solid-liquid separation device IV, and the solid outlet of the solid-liquid separation device IV is connected to the inlet of the epoxidation reaction system or the return Inlet of the collecting tank: the purpose of adding ammonia water is to convert it into ammonium salt containing molybdenum element. After evaporation and concentration by the evaporator IV, the concentration of ammonium salt containing molybdenum element rises to exceed its saturated solubility and precipitates. After the solid is separated by the solid-liquid separation device IV, it is reused in the epoxidation reaction system or recovered in the recovery tank. The solubility of sodium salt containing molybdenum element is higher than that of ammonium salt containing molybdenum element, so the ammonium salt containing molybdenum element is preferentially precipitated, that is, the precipitated solid is the ammonium salt containing molybdenum element. At the same time, a cooler can be provided between the evaporator IV and the solid-liquid separation device IV to reduce the temperature to further reduce the solubility of the ammonium salt containing molybdenum element, which is conducive to the precipitation of the ammonium salt containing molybdenum element;

[0042] Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the inlet of an incineration device, and the solid outlet of the incineration device is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank: the incineration device is used to burn and remove organic matter.

[0043] Based on the above treatment system, preferably, the ammonia adding device I or the ammonia adding device II is connected to an ammonia water pipeline to provide ammonia water;

[0044] And / or, the acid outlet of the bipolar membrane device, the water outlet of the ammonia addition device I, the water outlet of the ammonia addition device II, the solid outlet of the solid-liquid separation device I, the solid outlet of the solid-liquid separation device II, the solid outlet of the solid-liquid separation device III, the solid outlet of the solid-liquid separation device IV or the solid outlet of the incineration device are first connected to the inlet of the mixer or the inlet of the mixing tank, and the outlet of the mixer or the outlet of the mixing tank is then connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank.

[0045] Based on the above processing system, preferably, the mixer or the mixing tank is further provided with an inlet ', and chemicals are added to the inlet ' of the mixing tank.

[0046] Based on the above treatment system, preferably, a chemical is added to the inlet of the mixer or the mixing tank, and the chemical is isooctanoic acid.

[0047] Based on the above processing system, preferably, chemicals are added to the inlet of the mixer or the mixing tank, and the chemicals are isooctanoic acid and ethylbenzene.

[0048] Based on the above treatment system, preferably, the brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are connected to at least one of a wet oxidation device, a sewage biochemical treatment device and an incineration device, and the brine with low molybdenum content is a solution with a reduced molybdenum content and organic matter content ratio (compared with the water phase of the scrubber I) obtained after separation, that is, compared with the water phase of the scrubber I, the molybdenum concentration is lower and the organic matter concentration is similar, and the molybdenum content is less than that of the water phase of the scrubber I. Element content: The proportion of organic matter is reduced. In order to reduce its organic matter content and avoid environmental pollution, it needs to be treated by the wet oxidation device, and the cyclic organic matter is decomposed by the wet oxidation device; or it is treated by the sewage biochemical treatment device for biochemical treatment to reduce COD; or the cyclic organic matter is first decomposed by the wet oxidation device, and then treated by the sewage biochemical treatment device for biochemical treatment to reduce COD. The purpose of the first treatment by the wet oxidation device is to transform and destroy the cyclic organic matter, which will be beneficial to the treatment effect of the biochemical sewage flora. The biochemical sewage flora has a poor treatment effect on cyclic organic matter. The cyclic organic matter needs to be decomposed first, which is beneficial to the sewage biochemical treatment device for biochemical treatment to reduce COD; or the organic matter is directly incinerated;

[0049] Or the brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are connected to the water inlet of the wet oxidation device, and the water outlet of the wet oxidation device is connected to the sewage biochemical treatment device, and the brine with low molybdenum concentration is a solution with a reduced molybdenum content and a reduced organic matter content ratio (relative to the water of the scrubber I) after separation. Phase), that is, compared with the water phase of the scrubber I, its molybdenum concentration is lower and the organic matter concentration is similar, and the ratio of molybdenum content: organic matter is reduced. In order to reduce its organic matter content and avoid environmental pollution, the cyclic organic matter is first decomposed by the wet oxidation device, and then the wastewater biochemical treatment device is used for biochemical treatment to reduce COD. The purpose of the first treatment by the wet oxidation device is to transform and destroy the cyclic organic matter, which will be beneficial to the treatment effect of the biochemical sewage flora. The biochemical sewage flora has a poor treatment effect on cyclic organic matter. The cyclic organic matter needs to be decomposed first, which is beneficial to the biochemical treatment of the wastewater biochemical treatment device to reduce COD.

[0050] Based on the above treatment system, preferably, the wet oxidation device includes a high-temperature and high-pressure wet oxidation device (reaction pressure is close to 10 MPa).

[0051] Based on the above processing system, preferably, at least one of the concentrator I, the concentrator II, and the concentrator III is further provided;

[0052] The brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are first connected to the water inlet of the concentrator I, and the fresh water outlet or the concentrated liquid outlet of the concentrator I is then connected to at least one of the wet oxidation device, the sewage biochemical treatment device and the incineration equipment;

[0053] The concentrating device II is arranged between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I, between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I, between the water phase outlet of the scrubber I and the water inlet of the oil removal device, between the oil removal device and the water inlet of the separation membrane system I, between the oil removal device and the water inlet of the electric desalination system I, between the water phase outlet of the scrubber I and the water inlet of the deoxidation device, between the deoxidation device and the water inlet of the separation membrane system I, between the deoxidation device and the water inlet of the electric desalination system I between the water inlet of the system I, between the water inlet of the oil removal device to the water inlet of the oxidation elimination device, between the water inlet of the oxidation elimination device to the oil removal device, between the outlet of the brine with high molybdenum content of the separation membrane system I to the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system I to the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electric desalination system I to the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system I to the inlet of the recovery tank, and between the outlet of the brine with high molybdenum content of the separation membrane system I The brine with high molybdenum content is exported to the water inlet of the separation membrane system II, the brine with high molybdenum content of the separation membrane system I is exported to the water inlet of the electric desalination system II, the brine with high molybdenum content of the electric desalination system I is exported to the water inlet of the separation membrane system III, the brine with high molybdenum content of the electric desalination system I is exported to the water inlet of the electric desalination system III, the brine with high molybdenum content of the separation membrane system II is exported to the inlet of the epoxidation reaction system, and the brine with high molybdenum content of the electric desalination system II is exported to the inlet of the epoxidation reaction system. between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electrical desalination system III and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electrical desalination system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the electrical desalination system III and the inlet of the recovery tank;

[0054] The concentrating device III is arranged between the brine outlet with high molybdenum content of the separation membrane system I and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system II and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system II and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system III and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system III and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system I and the evaporating device. between the water inlet of the device III, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system II and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the electric desalination system II and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system III and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the electric desalination system III and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system I and the water inlet of the ammonia addition device II, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the ammonia addition device II between the outlet of the brine with high molybdenum content of the separation membrane system II and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the electric desalination system II and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the separation membrane system III and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the electric desalination system III and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the incineration device, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the incineration device, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the incineration device, between the brine outlet with high molybdenum content of the salt system II and the inlet of the incineration equipment, between the brine outlet with high molybdenum content of the separation membrane system III and the inlet of the incineration equipment, between the brine outlet with high molybdenum content of the electric desalination system III and the inlet of the incineration equipment, between the acid outlet of the bipolar membrane device and the inlet of the epoxidation reaction system, between the acid outlet of the bipolar membrane device and the inlet of the recovery tank, between the acid outlet of the bipolar membrane device and the water inlet of the evaporator I, between the acid outlet of the bipolar membrane device and the water inlet of the ammonia addition device I, between the water outlet of the ammonia addition device I and the inlet of the epoxidation reaction system, between the water outlet of the ammonia addition device I and the inlet of the recovery tank,Between the water outlet of the ammonia addition equipment I and the water inlet of the evaporator II, between the water outlet of the ammonia addition equipment II and the inlet of the epoxidation reaction system, between the water outlet of the ammonia addition equipment II and the inlet of the recovery tank, between the water outlet of the ammonia addition equipment II and the water inlet of the evaporator IV, between the acid outlet of the bipolar membrane device and the inlet of the mixer, between the water outlet of the ammonia addition equipment I and the inlet of the mixer, between the water outlet of the ammonia addition equipment II and the inlet of the mixer, between the acid outlet of the bipolar membrane device and the inlet of the mixing tank, between the water outlet of the ammonia addition equipment I and the inlet of the mixing tank, or between the water outlet of the ammonia addition equipment II and the inlet of the mixing tank;

[0055] The purpose of the concentrator I, the concentrator II or the concentrator III is to concentrate, and the concentrated liquid with increased concentration is forwarded to the next step for processing.

[0056] Based on the above treatment system, preferably, the brine outlet of the bipolar membrane device is connected to the water inlet of the concentrator IV, and the concentrated liquid outlet of the concentrator IV is connected to the water inlet of the bipolar membrane device.

[0057] Based on the above processing system, preferably, the concentrating device I, the concentrating device II, the concentrating device III or the concentrating device IV includes at least one of a reverse osmosis concentrating device, an electrodialysis concentrating device or an evaporation concentrating device.

[0058] Based on the above treatment system, preferably, the scrubber I is further provided with an alkali adding pipeline and / or a water adding pipeline, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water;

[0059] Or a scrubber II is further provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the liquid outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water;

[0060] Or a scrubber II is further provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the liquid outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber I is further provided with an alkali adding pipeline and / or a water adding pipeline; the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water, generally, the scrubber II is used for alkali washing, and the scrubber I is used for water washing;

[0061] Or a scrubber II is further provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water;

[0062] Or a scrubber II is further provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber I is further provided with an alkali adding pipeline and / or a water adding pipeline; the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water, generally, the scrubber II is used for alkali washing, and the scrubber I is used for water washing;

[0063] Or a scrubber II is further provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline; the water phase outlet of the scrubber II is connected to the water inlet of the separation membrane system I, the water inlet of the electric desalination system I, the water inlet of the oil removal device, the water inlet of the oxidation elimination device or the water inlet of the concentration device II, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water, that is, the water phase outlet of the scrubber II is mixed with the water phase outlet of the scrubber I for the same treatment;

[0064] Or a scrubber II is also provided, the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber I is also provided with an alkali adding pipeline and / or a water adding pipeline; the scrubber II is also provided with an alkali adding pipeline and / or a water adding pipeline; the water phase outlet of the scrubber II is connected to the water inlet of the separation membrane system I, the water inlet of the electric desalination system I, the water inlet of the oil removal device, the water inlet of the oxidation elimination device or the water inlet of the concentration device II, the purpose of adding alkali is to dissolve phenol and other organic impurities with alkali; the purpose of adding water is to wash the ions therein with water. Generally, alkali is added to the scrubber II for alkali washing and water washing is performed with the scrubber I, that is, the water phase outlet of the scrubber II is mixed with the water phase outlet of the scrubber I for the same treatment.

[0065] Based on the above processing system, preferably,

[0066] A flash tank is also provided between the outlet of the depropanization tower discharge liquid and the inlet of the scrubber I, or between the outlet of the depropanization tower discharge liquid and the inlet of the scrubber II;

[0067] Alternatively, a flash tank and a cooler are provided between the outlet of the depropanol tower effluent and the inlet of the scrubber I, or between the outlet of the depropanol tower effluent and the inlet of the scrubber II, the outlet of the depropanol tower effluent is connected to the inlet of the flash tank, the liquid phase outlet of the flash tank is connected to the inlet of the cooler, and the outlet of the cooler is connected to the inlet of the scrubber I or the inlet of the scrubber II.

[0068] Based on the above processing system, preferably, the gas phase outlet of the flash tank is connected to a low-pressure depropanization tower.

[0069] Based on the above treatment system, preferably, the separation membrane system I, the separation membrane system II or the separation membrane system III adopts a nanofiltration membrane system; the main component in the nanofiltration membrane system is the nanofiltration membrane (a high-pressure pump for providing pressure is provided before the nanofiltration membrane), and the nanofiltration membrane is a membrane device used to separate monovalent ions and "divalent and above ions" under the action of pressure. In theory, the nanofiltration membrane can pass through monovalent ions, but can intercept divalent and above ions. Small molecular organic matter can also pass through the nanofiltration membrane, and the high-pressure pump is used to provide power. For the water phase of the scrubber I and / or the water phase of the scrubber II, the molybdenum anion contained therein is ≥ divalent anion (for example, dimolybdate anion is a negative divalent anion), so it will be intercepted on the concentrated water side of the nanofiltration membrane to obtain concentrated (that is, the brine with high molybdenum content in the nanofiltration membrane system, that is, the separation membrane system I, the separation membrane system II or the separation membrane The brine with high molybdenum content in system III is obtained by intercepting ≥ divalent molybdenum-containing anions and concentrating them using a nanofiltration membrane system), and the organic matter and monovalent ion salts in the water phase of the scrubber I and / or the water phase of the scrubber II will pass through the nanofiltration membrane (but the molybdenum anions therein are ≥ divalent anions and theoretically will not pass through the nanofiltration membrane) to form the brine with low molybdenum content in the nanofiltration membrane system, that is, the brine with low molybdenum content in the separation membrane system I, the separation membrane system II or the separation membrane system III is the monovalent anions and small molecular organic matter that pass through the nanofiltration membrane; the cation (sodium ion) concentration will automatically match the anion concentration in the brine with high molybdenum content and the anion concentration in the brine with low molybdenum content according to charge neutrality; and for the brine with high molybdenum content, that is, the ratio of the total amount of molybdenum element: the total amount of organic matter therein is increased, that is, the material to be recovered by the utility model;

[0070] That is, the nanofiltration membrane is used to achieve the effect of separating ≥ divalent anions (anions containing molybdenum elements) and "monovalent ions and organic matter". The nanofiltration membrane intercepts ≥ divalent anions (anions containing molybdenum elements) as concentrated water of the nanofiltration membrane, and the nanofiltration membrane passes monovalent ions and organic matter (wherein the molybdenum content is relatively low) as fresh water of the nanofiltration membrane. The organic matter content in the brine with low molybdenum content in the nanofiltration membrane system and the brine with high molybdenum content in the nanofiltration membrane system are similar, but for inorganic matter, the brine with low molybdenum content in the nanofiltration membrane system is rich in monovalent ions, and the brine with high molybdenum content in the nanofiltration membrane system is rich in ≥ divalent anions (anions containing molybdenum elements). We hope to separate components mainly containing ≥ divalent anions (anions containing molybdenum elements) and containing monovalent anions and less organic matter from the water phase of the scrubber I and / or the water phase of the scrubber II, so we need brine with high molybdenum content in the nanofiltration membrane system. Since the output (water volume) of brine with high molybdenum content is lower than that of the scrubber, The water phase flow of scrubber I and the water phase flow of scrubber II (i.e., the influent water treatment volume of the nanofiltration membrane system) are significantly reduced. Therefore, in terms of total amount, the brine with high molybdenum content is equivalent to extracting a solution rich in divalent anions (anions containing molybdenum elements) from the water phase of scrubber I and / or the water phase of scrubber II. Compared with the water phase of scrubber I and / or the water phase of scrubber II, the proportion of divalent anions (anions containing molybdenum elements) is significantly increased (i.e., the ratio of the total amount of molybdenum elements: the total amount of organic matter is increased). The main function of the nanofiltration membrane used in the utility model is separation. Even if the concentration of divalent anions (anions containing molybdenum elements) in the final actual nanofiltration membrane concentrate is low due to large dilution, the proportion of divalent anions (anions containing molybdenum elements) is increased, so it is also called "salt water with high molybdenum content". In the utility model, "salt water with high molybdenum content" refers to the increase in the proportion of molybdenum elements.

[0071] Or the electro-desalting system I, the electro-desalting system II or the electro-desalting system III, using an electrodialysis device, the inorganic ions in the water phase of the scrubber I and / or the water phase of the scrubber II (i.e., the influent of the electrodialysis device) are strongly charged and easily attracted by the electric field, while the unionized organic matter therein is uncharged and will not be attracted by the electric field, and the ionized organic matter is weakly charged although charged, and is not easily attracted by the electric field relative to the inorganic matter, so after being treated by the electrodialysis device, the strongly charged inorganic ions (e.g., anions containing molybdenum elements) are attracted by the electric field and pass through the anion membrane (anions, such as anions containing molybdenum elements) and cation membrane (cations, such as sodium ions) of the electrodialysis to enter the concentration chamber to obtain salt water with a high content of molybdenum elements, and the strongly charged inorganic ions (e.g., anions containing molybdenum elements) in the influent chamber enter the concentration chamber, resulting in a decrease in their content in the influent chamber, thus becoming salt water with a low content of molybdenum elements;

[0072] The organic matter content in the brine with high molybdenum content is similar to that in the brine with low molybdenum content, and both are similar to the organic matter content in the water phase of the scrubber I and / or the water phase of the scrubber II; therefore, the electrodialysis treatment actually plays a role in separating strongly charged inorganic ions (such as anions containing molybdenum) and organic matter (impurities), and the obtained brine with high molybdenum content is mainly an aqueous solution rich in inorganic ions (referring to molybdenum-containing inorganic substances), wherein the organic matter content is similar to that in the water phase of the scrubber I and / or the water phase of the scrubber II, but because the output (water volume) of the brine with high molybdenum content is significantly lower than the flow rate of the water phase of the scrubber I and the water phase of the scrubber II (i.e., the water volume of the inlet treatment water of the electrodialysis equipment), the total In terms of quantity, the brine with a high molybdenum content is equivalent to extracting a solution rich in inorganic matter (referring to molybdenum-containing inorganic matter) from the water phase of the scrubber I and / or the water phase of the scrubber II (that is, the ratio of the total amount of molybdenum element: the total amount of organic matter is increased). The main function of the electrodialysis equipment used in the utility model is separation. Even if the concentration of anions rich in ≥ divalent anions (anions containing molybdenum) in the actual electrodialysis equipment concentration chamber is low due to the large dilution of the water supply to the concentration chamber (as the receiving liquid for ions passing through the anion membrane and the cation membrane), the proportion of anions rich in ≥ divalent anions (anions containing molybdenum) is increased, it is also called "salt water with a high molybdenum content". In the utility model, "salt water with a high molybdenum content" refers to an increase in the proportion of molybdenum.

[0073] Based on the above treatment system, preferably, the depropanation tower is connected to the epoxidation reaction system (epoxidation reactor) of the propylene oxide production process. In the epoxidation reaction system (epoxidation reactor), propylene and EBHP undergo liquid-phase epoxidation reaction in the presence of a molybdenum-based catalyst (e.g., ammonium dimolybdate) to generate propylene oxide (PO) and MBA, propylene+EBHP→PO+MBA, so the material components discharged from the epoxidation reactor into the depropanation tower are mainly PO, MBA, unreacted propylene (needs to be removed), etc., and molybdenum-containing inorganic substances (as catalysts for the epoxidation reaction);

[0074] Or the depropanation tower is a high-pressure depropanation tower of a propylene oxide production process, and the high-pressure depropanation tower is connected to an epoxidation reactor of the propylene oxide production process, and is used to remove propylene from materials discharged from the epoxidation reaction system (epoxidation reactor), and the remainder is mainly propylene oxide (PO) and MBA, and also contains a molybdenum-containing catalyst;

[0075] Or the outlet of the de-propanization tower discharge liquid is the outlet of the tower bottom liquid of the de-propanization tower, the de-propanization tower removes propylene from the material discharged from the epoxidation reaction system (epoxidation reactor), and the remainder contains propylene oxide (PO) and MBA, propylene that is not completely removed, and a molybdenum-containing catalyst, propylene is discharged from the top of the de-propanization tower, and the tower bottom liquid of the de-propanization tower contains propylene oxide (PO) and MBA, propylene that is not completely removed, and a molybdenum-containing catalyst, which is the de-propanization tower discharge liquid;

[0076] Or the depropanization tower is a high-pressure depropanization tower of a propylene oxide production process, the high-pressure depropanization tower is connected to the epoxidation reactor of the propylene oxide production process, and is used to remove propylene from the material discharged from the epoxidation reaction system (epoxidation reactor), the outlet of the depropanization tower discharge liquid is the outlet of the tower bottom liquid of the high-pressure depropanization tower, containing propylene oxide (PO) and MBA, propylene that is not completely removed, and a molybdenum-containing catalyst, propylene is discharged from the top of the high-pressure depropanization tower, and the tower bottom liquid of the high-pressure depropanization tower contains propylene oxide (PO) and MBA, propylene that is not completely removed, and a molybdenum-containing catalyst, which is the depropanization tower discharge liquid; the propylene oxide production process is also provided with a low-pressure depropanization tower;

[0077] Or the oil phase outlet of the scrubber I is connected to the inlet of a low-pressure depropanization tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of a low-pressure depropanization tower, and the low-pressure depropanization tower is used to further remove propylene;

[0078] Or the oil phase outlet of the scrubber II is connected to the inlet of a low-pressure depropanization tower, or the oil phase outlet of the scrubber II is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of a low-pressure depropanization tower, and the low-pressure depropanization tower is used to further remove propylene.

[0079] Based on the above processing system, preferably, propylene is discharged from the top of the depropanization tower, or propylene is discharged from the top of the high-pressure depropanization tower, and then cooled and used as a propylene raw material to enter the epoxidation reactor for reuse.

[0080] Based on the above treatment system, preferably, the alkali outlet of the bipolar membrane device is connected to the alkali adding pipeline for providing alkali solution; or the alkali outlet of the bipolar membrane device is collected; or the alkali outlet of the bipolar membrane device is discharged.

[0081] Based on the above treatment system, preferably, the EBHP refers to ethylbenzene hydroperoxide, C 8 H 10 O 2 .

[0082] Based on the above processing system, preferably, the MBA refers to methyl benzyl alcohol, C 8 H10 O.

[0083] Beneficial Effects

[0084] The purpose of the utility model is to provide a treatment system for the effluent of the depropanol tower in the propylene oxide production process. After being treated by the treatment system, the molybdenum-containing compounds separated can be recycled and reused, and the economic value of the molybdenum-containing compounds can be recovered. After the effluent of the depropanol tower is treated by the system, the molybdenum element can be extracted and converted into products for reuse, and the economic value of the molybdenum element can be recovered.

[0085] In addition, the system is simple to operate, the equipment is simple, the operation is easy and the operation is stable, which is very helpful in reducing the operating costs of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 Schematic diagram of a processing system according to Embodiment 1.

[0087] Figure 2 Schematic diagram of the processing system of Example 2.

[0088] Figure 3 Schematic diagram of the processing system of Example 3.

[0089] Figure 4 Schematic diagram of the processing system of Example 4.

[0090] Figure 5 Schematic diagram of the processing system of Example 5.

[0091] Figure 6 Schematic diagram of the processing system of Example 6.

[0092] Figure 7 Schematic diagram of the processing system of Example 7.

[0093] Figure 8 Schematic diagram of the processing system of Example 8.

[0094] Fig. 9 Schematic diagram of the processing system of Example 9.

[0095] Fig.10 Schematic diagram of the processing system of Example 10.

[0096] Fig.11 Schematic diagram of the processing system of Example 11.

[0097] Fig.12 Schematic diagram of the processing system of Example 12.

[0098] legend:

[0099]

[0100] DETAILED DESCRIPTION

[0101] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0102] Embodiment 1:

[0103] A depropanation tower effluent treatment system for a propylene oxide production process mainly includes a depropanation tower 001, a scrubber Ⅰ002, a separation membrane system Ⅰ008 (including a high-pressure pump 007), a recovery tank 011 or an epoxidation reaction system 013.

[0104] The effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ (nanofiltration membrane is selected) 008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008. The separation membrane system Ⅰ008 is also provided with a molybdenum The brine outlet 009 with high molybdenum content and the brine outlet 010 with low molybdenum content, the brine outlet 009 with high molybdenum content of the separation membrane system I 008 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process, the epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, a discharge port 012, the discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0105] The above processing system operates as follows:

[0106] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0107] The effluent from the effluent outlet 006 (referring to the bottom liquid outlet) of the depropanization tower 001 (the present embodiment is a high-pressure depropanization tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, an aqueous phase outlet 005 and an oil phase outlet 004, are obtained. The aqueous phase of the aqueous phase outlet 005 of the scrubber Ⅰ002 is pressurized by a high-pressure pump 007 and then processed by a separation membrane system Ⅰ008 (nanofiltration membrane is selected). The solution of the brine outlet 009 with a high molybdenum content is obtained and enters a recovery tank 011 for recovery, or enters an epoxidation reaction system 013 for reuse in the epoxidation reaction.

[0108] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system 013 (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0109] Run the experiment using the above system:

[0110] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0111] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0112] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0113] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0114] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0115] in conclusion:

[0116] 1. It is obvious that in the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0117] 2. At the same time, since molybdenum is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum to the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly increased, that is, the molybdenum is purified (most of the organic matter is separated from the molybdenum), and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum is recovered (as a catalyst) and the organic impurities it carries are less. As for the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008, most of it is discharged from the brine outlet 010 with a low molybdenum content, and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0118] Note: In all embodiments of the present invention, the nanofiltration membrane used is DuPont's FilmTec TM Fortilife TM XC-N, the reverse osmosis membrane used in the reverse osmosis concentration device is DuPont brand SW30HRLE-440i, the electrodialysis equipment is EX-4S-ED provided by Hangzhou Lanran Technology Co., Ltd., and the bipolar membrane equipment is EX-4S provided by Hangzhou Lanran Technology Co., Ltd.

[0119] Embodiment 2:

[0120] A depropylene tower effluent treatment system for a propylene oxide production process mainly comprises a depropylene tower 001, a scrubber Ⅰ002, an electric desalination system Ⅰ016, a recovery tank 011 or an epoxidation reaction system 013.

[0121] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, a water phase outlet 005, and an oil phase outlet 004. The water phase outlet 005 of the scrubber Ⅰ002 is connected to the water inlet of the electric desalination system Ⅰ016 (selecting an electrodialysis device), and the electric desalination system Ⅰ016 is also provided with a brine outlet 017 with a high molybdenum content and a molybdenum salt water outlet 018. The brine outlet 018 with low element content and the brine outlet 017 with high molybdenum content of the electric desalination system I 016 are connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0122] The above processing system operates as follows:

[0123] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0124] The effluent from the effluent outlet 006 (referring to the bottom liquid outlet) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, a water phase outlet 005 and an oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber Ⅰ002 is treated by the electric desalination system Ⅰ016 (electrodialysis equipment is selected), and the solution of the brine outlet 017 with a high molybdenum content is obtained to enter the recovery tank 011 for recovery, or enter the epoxidation reaction system 013 to be reused in the epoxidation reaction.

[0125] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0126] Run the experiment using the above system:

[0127] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0128] The water volume of the brine outlet 017 with high molybdenum content of the electric desalination system Ⅰ016 (electrodialysis equipment is selected) accounts for about 4% of the water inlet of the electric desalination system Ⅰ016 (electrodialysis equipment is selected). The sampling and analysis of the brine outlet 017 with high molybdenum content of the electric desalination system Ⅰ016 (electrodialysis equipment is selected) are as follows: PH=12.41, CODcr=108600ppm, molybdenum element=28032ppm.

[0129] That is, after being processed by the electric desalination system I016 (selecting an electrodialysis device), the brine outlet 017 with a high molybdenum content is obtained:

[0130] The total amount of molybdenum in the influent water = 28032ppm × 4% ÷ 1190ppm = 94%;

[0131] The total amount of organic matter accounts for 3% of the total amount of organic matter in the influent water = 108600ppm × 4% ÷ 152100ppm = 3%.

[0132] in conclusion:

[0133] 1. It is obvious that in the brine outlet 017 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the electric desalination system Ⅰ016 (using electrodialysis equipment), which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0134] 2. At the same time, since molybdenum is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the electro-desalting system I 016 (selecting electrodialysis equipment), the ratio of the total amount of molybdenum to the total amount of organic matter in the brine outlet 017 with a high molybdenum content is significantly increased, that is, the molybdenum is purified (most of the organic matter and molybdenum are separated), and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum is recovered (as a catalyst) and the organic impurities carried by it are ensured to be less. For the organic matter in the influent of the electro-desalting system I 016 (selecting electrodialysis equipment), most of them are discharged from the brine outlet 018 with a low molybdenum content, and are not recovered in the epoxidation reaction system 013 (epoxidation reactor).

[0135] At the same time, it is also proved that the effect of the electric desalination system Ⅰ016 (electrodialysis equipment is selected) is exactly the same as the effect of the separation membrane system Ⅰ (nanofiltration membrane) 008 of Example 1, that is, the effect of the electric desalination system (electrodialysis equipment is selected) and the separation membrane system (nanofiltration membrane) are exactly the same, they can be interchanged as units, and the effects are equivalent.

[0136] Embodiment three:

[0137] A depropylene tower effluent treatment system for propylene oxide production process mainly includes a depropylene tower 001, a scrubber Ⅰ 002, a separation membrane system Ⅰ 008 (including a high-pressure pump 007), an electric desalination system Ⅱ (selecting an electrodialysis device) 019, a recovery tank 011 or an epoxidation reaction system 013.

[0138] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of the separation membrane system Ⅰ008 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008. To the water inlet of the electric desalination system II 019 (electrodialysis equipment is selected), the electric desalination system II (electrodialysis equipment is selected) 019 is also provided with a brine outlet 020 with a high molybdenum content and a brine outlet 021 with a low molybdenum content, the brine outlet 020 with a high molybdenum content of the electric desalination system II (electrodialysis equipment is selected) 019 is connected to the import of the recovery tank 011 or the epoxidation reactor 013 of the propylene oxide production process, the epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, a discharge port 012, the discharge port 012 of the epoxidation reactor 013 is connected to the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process).

[0139] The above processing system operates as follows:

[0140] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0141] The effluent from the effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber I 002 (the source is the alkali addition pipeline 003), and two products, an aqueous phase outlet 005 and an oil phase outlet 004, are obtained. The aqueous phase of the aqueous phase outlet 005 of the scrubber I 002 is pressurized by a high-pressure pump 007 and then processed by a separation membrane system I 008 (a nanofiltration membrane is selected). The obtained brine outlet 009 with a high molybdenum content is processed by an electric desalination system II (an electrodialysis device is selected) 019. The solution of the brine outlet 020 with a high molybdenum content of the electric desalination system II (an electrodialysis device is selected) 019 enters a recovery tank 011 for recovery, or enters an epoxidation reaction system 013 and is reused in the epoxidation reaction.

[0142] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0143] Run the experiment using the above system:

[0144] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0145] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0146] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0147] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0148] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0149] The water volume of the brine outlet 020 with high molybdenum content of the electric desalination system II (electrodialysis equipment is selected) 019 accounts for about 30% of the water inlet of the electric desalination system II (electrodialysis equipment is selected) 019. The sampling and analysis of the brine outlet 020 with high molybdenum content of the electric desalination system II (electrodialysis equipment is selected) 019 are as follows: PH = 12.42, CODcr = 88800ppm, molybdenum element = 30315ppm.

[0150] That is, the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 is further processed by the electric desalination system II 019 (selecting an electrodialysis device), and the brine outlet 020 with high molybdenum content is obtained:

[0151] The total amount of molybdenum in the influent water = 30315ppm × 30% ÷ 10215ppm = 89%;

[0152] The total amount of organic matter accounts for the total amount of organic matter in the influent water = 88800ppm × 30% ÷ 121900ppm = 22%.

[0153] in conclusion:

[0154] 1. After being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the brine outlet 009 with a high molybdenum content is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the influent of the separation membrane system I (nanofiltration membrane) 008; the brine outlet 009 with a high molybdenum content is further treated by the electrical desalination system II (electrodialysis equipment is selected) 019, and the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 020 with a high molybdenum content is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter in the influent of the electrical desalination system II (electrodialysis equipment is selected) 019, which is equivalent to a good separation of inorganic and organic matter containing molybdenum elements, which is beneficial to reducing the proportion of organic impurities in inorganic matter containing molybdenum elements.

[0155] 2. Since molybdenum is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008 and the electric desalination system II (selecting an electrodialysis device) 019, the ratio of the total amount of molybdenum element to the total amount of organic matter in the brine with a high molybdenum concentration is significantly increased, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element is recovered (as a catalyst) and the organic impurities carried by it are ensured to be less. For the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008, most of them are discharged from the brine outlet 010 with a low molybdenum content and the brine outlet 021 with a low molybdenum content, and are not recovered in the epoxidation reaction system 013 (epoxidation reactor).

[0156] Since Example 2 proves that the effects of the separation membrane system (nanofiltration membrane) and the electrical desalination system (electrodialysis equipment) are the same, it can be inferred that on the basis of Example 3, the electrical desalination system II (electrodialysis equipment) 019 is replaced with the separation membrane system II, and the effect is the same.

[0157] Embodiment 4:

[0158] A depropanation tower effluent treatment system for a propylene oxide production process mainly includes a depropanation tower 001, a scrubber Ⅰ 002, an electric desalination system Ⅰ 016, a separation membrane system Ⅲ (nanofiltration membrane) 023 (including a high-pressure pump 022), a recovery tank 011 or an epoxidation reaction system 013.

[0159] The effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the water inlet of the electric desalination system Ⅰ016 (an electrodialysis device is selected), and the electric desalination system Ⅰ016 is also provided with a brine outlet 017 with a high molybdenum content and a brine outlet 018 with a low molybdenum content. The brine outlet 017 with a high molybdenum content of the electric desalination system Ⅰ016 is connected to the inlet of the high-pressure pump 022 of the separation membrane system Ⅲ (nanofiltration membrane) 023, and the high-pressure pump The outlet of 022 is connected to the water inlet of separation membrane system III 023 (nanofiltration membrane is selected), and the separation membrane system III (nanofiltration membrane) 023 is also provided with a brine outlet 024 with a high molybdenum content and a brine outlet 025 with a low molybdenum content. The brine outlet 024 with a high molybdenum content of the separation membrane system III (nanofiltration membrane) 023 is connected to the inlet of the recovery tank 011 or the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0160] The above processing system operates as follows:

[0161] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0162] The effluent from the effluent outlet 006 (referring to the bottom liquid outlet) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, an aqueous phase outlet 005 and an oil phase outlet 004, are obtained. The aqueous phase of the aqueous phase outlet 005 of the scrubber Ⅰ002 is treated by the electric desalination system Ⅰ016 (electrodialysis equipment is selected), and the obtained brine outlet 017 with a high molybdenum content is pressurized by the high-pressure pump 022 and then treated by the separation membrane system Ⅱ023 (nanofiltration membrane is selected), and the solution of the brine outlet 024 with a high molybdenum content enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 for reuse in the epoxidation reaction.

[0163] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0164] Run the experiment using the above system:

[0165] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0166] The water volume of the brine outlet 017 with high molybdenum content of the electric desalination system Ⅰ016 (electrodialysis equipment is selected) accounts for about 4% of the water inlet of the electric desalination system Ⅰ016 (electrodialysis equipment is selected). The sampling and analysis of the brine outlet 017 with high molybdenum content of the electric desalination system Ⅰ016 (electrodialysis equipment is selected) are as follows: PH=12.41, CODcr=108600ppm, molybdenum element=28032ppm.

[0167] That is, after being processed by the electric desalination system I016 (selecting an electrodialysis device), the brine outlet 017 with a high molybdenum content is obtained:

[0168] The total amount of molybdenum in the influent water = 28032ppm × 4% ÷ 1190ppm = 94%;

[0169] The total amount of organic matter accounts for 3% of the total amount of organic matter in the influent water = 108600ppm × 4% ÷ 152100ppm = 3%.

[0170] The water volume of the brine outlet 024 with high molybdenum content of the separation membrane system III (nanofiltration membrane) 023 accounts for about 50% of the water inlet volume of the separation membrane system III (nanofiltration membrane) 023. The sampling and analysis of the brine outlet 024 with high molybdenum content of the separation membrane system III (nanofiltration membrane) 023 are as follows: PH = 12.15, CODcr = 91250ppm, molybdenum element = 50814ppm.

[0171] That is, after being processed by the separation membrane system III (nanofiltration membrane) 023, the brine outlet 024 with a high molybdenum content is obtained:

[0172] The total amount of molybdenum in the influent water = 50814ppm × 50% ÷ 28032ppm = 91%;

[0173] The total amount of organic matter accounts for the total amount of organic matter in the influent water = 91250ppm×50%÷108600ppm=42%.

[0174] in conclusion:

[0175] 1. After being treated by the electro-desalting system I 016 (using electrodialysis equipment), the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the brine outlet 017 with a high molybdenum content is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the influent of the electro-desalting system I 016 (using electrodialysis equipment); the brine outlet 017 with a high molybdenum content is further treated by the separation membrane system III (nanofiltration membrane) 023, and the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 024 with a high molybdenum content is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter in the influent of the separation membrane system III (nanofiltration membrane) 023, which is equivalent to a good separation of inorganic and organic matter containing molybdenum elements, which is beneficial to reducing the proportion of organic impurities in inorganic matter containing molybdenum elements.

[0176] 2. Since molybdenum is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the electro-desalting system I 016 (selecting electrodialysis equipment) and the separation membrane system III (nanofiltration membrane) 023, the ratio of the total amount of molybdenum element in the brine with high molybdenum concentration to the total amount of organic matter is significantly increased, that is, the molybdenum element is purified (most of the organic matter and molybdenum element are separated), and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element is recovered (as a catalyst) and the organic impurities carried by it are ensured to be less. For the organic matter in the influent of the electro-desalting system I 016 (selecting electrodialysis equipment), most of them are discharged from the brine outlet 018 with low molybdenum content and the brine outlet 025 with low molybdenum content, and are not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0177] Since Example 2 proves that the effects of the separation membrane system (nanofiltration membrane) and the electrical desalination system (electrodialysis equipment) are the same, it can be inferred that on the basis of Example 4, the separation membrane system III (nanofiltration membrane) 023 is replaced with the electrical desalination system III, and the effect is the same.

[0178] Embodiment five:

[0179] A depropylene tower effluent treatment system for a propylene oxide production process mainly includes a depropylene tower 001, a scrubber Ⅰ002, an oil removal device (oil separator) 026, a separation membrane system Ⅰ008 (including a high-pressure pump 007), a recovery tank 011 or an epoxidation reaction system 013.

[0180] The effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali adding pipeline 003, a water phase outlet 005, and an oil phase outlet 004. The water phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the oil removal device (oil separator) 026, and the oil removal device (oil separator) 026 is also provided with a water phase outlet 027 and an oil phase outlet 028. The water phase outlet 027 of the oil removal device (oil separator) 026 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ (nanofiltration membrane is selected) 008, and the high-pressure pump The outlet of 007 is connected to the water inlet of separation membrane system I 008. Separation membrane system I 008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of separation membrane system I 008 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0181] The above processing system operates as follows:

[0182] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0183] The effluent from the effluent outlet 006 (referring to the bottom liquid outlet) of the depropanization tower 001 (the present embodiment is a high-pressure depropanization tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, namely, the water phase outlet 005 and the oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber Ⅰ002 is deoiled by the oil removal device (oil separator) 026, and then pressurized by the high-pressure pump 007 and processed by the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The solution of the brine outlet 009 with a high molybdenum content is obtained and enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 for reuse in the epoxidation reaction.

[0184] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0185] Run the experiment using the above system:

[0186] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0187] The water phase outlet 027 of the oil removal device (oil separator) 026 was sampled and analyzed as follows: black color, PH = 12.47, conductivity = 217 ms / cm, CODcr = 133120 ppm, molybdenum element = 1159 ppm.

[0188] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 119300 ppm, molybdenum element = 9842 ppm.

[0189] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0190] The total amount of molybdenum in the influent water = 9842ppm × 10% ÷ 1159ppm = 85%;

[0191] The total amount of organic matter accounts for 9% of the total amount of organic matter in the influent water = 119300ppm × 10% ÷ 133120ppm = 9%.

[0192] Conclusion: That is, on the basis of Example 1, the treatment of adding the oil removal device (oil separator) 026 has the same effect as that of Example 1. Adding the oil removal device (oil separator) 026 can avoid the oil content entering the separation membrane system I (nanofiltration membrane) 008 and increase the cleaning interval of the separation membrane system I (nanofiltration membrane) 008.

[0193] Since Example 2 proves that the effects of the separation membrane system (nanofiltration membrane) and the electric desalination system (electrodialysis equipment) are the same, it can be inferred that adding an oil removal device (oil separator) 026 on the basis of Example 2 will produce the same result as that of Example 2; or on the basis of this Example 5, replacing the separation membrane system I (nanofiltration membrane) 008 with the electric desalination system I 016 (electrodialysis equipment) will produce the same effect.

[0194] Embodiment six:

[0195] A depropanation tower effluent treatment system for a propylene oxide production process mainly includes a depropanation tower 001, a scrubber II 029, a scrubber I 002, an oil removal device (oil separator) 026, a separation membrane system I 008 (including a high-pressure pump 007), a recovery tank 011 or an epoxidation reaction system 013.

[0196] The effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber II 029, and the scrubber II 029 is also provided with an alkali adding pipeline 033, a water phase outlet 030, and an oil phase outlet 031. The oil phase outlet 031 of the scrubber II 029 is connected to the inlet of the scrubber I 002, and the scrubber I 002 is also provided with a water adding pipeline 032, a water phase outlet 005, and an oil phase outlet 004. The water phase outlet 005 of the scrubber I 002 is connected to the inlet of the oil removal device (oil separator) 026, and the water phase outlet 030 of the scrubber II 029 is also connected to the inlet of the oil removal device (oil separator) 026. The oil removal device (oil separator) 026 is also provided with a water phase outlet 027 and an oil phase outlet 028. The oil removal device The water phase outlet 027 of the (oil separator) 026 is connected to the inlet of the high-pressure pump 007 of the separation membrane system I (nanofiltration membrane is selected) 008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system I 008. The separation membrane system I 008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of the separation membrane system I 008 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0197] The above processing system operates as follows:

[0198] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0199] The effluent from the effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanization tower 001 (this embodiment is a high-pressure depropanization tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber II 029 (the source is the alkali addition pipeline 033), and two products, a water phase outlet 030 and an oil phase outlet 031, are obtained. The oil phase outlet 031 of the scrubber II 029 is then washed with water in the scrubber I 002 (the source is the water addition pipeline 032), and a water phase outlet 00 5. The water phase of the two outlets, oil phase outlet 004, water phase outlet 030 of scrubber II 029 and water phase outlet 005 of scrubber I 002 are deoiled by deoiling device (oil separator) 026, pressurized by high pressure pump 007 and then processed by separation membrane system I 008 (nanofiltration membrane is selected), and the solution of brine outlet 009 with high molybdenum content is recycled into recovery tank 011, or enters epoxidation reaction system 013 and reused in epoxidation reaction.

[0200] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0201] Run the experiment using the above system:

[0202] The water phase outlet 027 of the oil removal device (oil separator) 026 was sampled and analyzed as follows: black color, PH = 13.31, conductivity = 288ms / cm, CODcr = 112100ppm, molybdenum element = 1066ppm.

[0203] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 89100ppm, molybdenum element = 9667ppm.

[0204] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0205] The total amount of molybdenum in the influent water = 9667ppm × 10% ÷ 1066ppm = 91%;

[0206] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 89100ppm × 10% ÷ 112100ppm = 8%.

[0207] Conclusion: On the basis of Example 1, a scrubber II 029 (adding alkali) is added before the scrubber I 002 (adding water), and then the oil is treated by the oil removal device (oil separator) 026. The effect is exactly the same as in Example 1. Adding the oil removal device (oil separator) 026 can avoid the oil content entering the separation membrane system I (nanofiltration membrane) 008 and increase the cleaning interval of the separation membrane system I (nanofiltration membrane) 008.

[0208] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of Example 6, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

[0209] Embodiment seven:

[0210] A depropanation tower effluent treatment system for a propylene oxide production process mainly includes a depropanation tower 001, a scrubber Ⅰ002, a separation membrane system Ⅰ008 (including a high-pressure pump 007), a concentration device Ⅲ035 (a reverse osmosis concentration device, including a high-pressure pump 034), a bipolar membrane device 038, a concentration device Ⅳ066 (a reverse osmosis concentration device, including a high-pressure pump 065), a recovery tank 011 or an epoxidation reaction system 013.

[0211] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the inlet of the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of the separation membrane system Ⅰ008 is connected to the inlet of the high-pressure pump 034 of the concentrator Ⅲ035 (reverse osmosis concentrator). The outlet of the high-pressure pump 034 is connected to the water inlet of the concentrator Ⅲ035. The concentrator Ⅲ035 is provided with a concentrate outlet 036 and a fresh water outlet 037. The concentrate outlet 036 of the concentrator Ⅲ035 is connected to the inlet of the high-pressure pump 034. The bipolar membrane device 038 is connected to the water inlet, and the bipolar membrane device 038 is provided with an alkali outlet 041, a salt water outlet 040, and an acid outlet 039. The salt water outlet 040 of the bipolar membrane device 038 is connected to the inlet of the high-pressure pump 065 of the concentrator IV 066 (reverse osmosis concentrator), and the outlet of the high-pressure pump 065 is connected to the water inlet of the concentrator IV 066. The concentrator IV 066 (reverse osmosis concentrator) is also provided with a concentrate outlet 067 and a fresh water outlet 068. The liquid outlet 067 is connected to the water inlet of the bipolar membrane device 038; the acid outlet 039 of the bipolar membrane device 038 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process, and the epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0212] The above processing system operates as follows:

[0213] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0214] The effluent from the effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber I 002 (the source is the alkali addition pipeline 003), and two products, namely, the aqueous phase outlet 005 and the oil phase outlet 004, are obtained. The aqueous phase of the aqueous phase outlet 005 of the scrubber I 002 is pressurized by the high-pressure pump 007 and then processed by the separation membrane system I 008 (nanofiltration membrane is selected). The brine outlet 009 with a high molybdenum content is concentrated by the concentrator III 035 (reverse osmosis concentrator) and then processed by the bipolar membrane device 038. The acid produced by the bipolar membrane device 038 enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 and is reused in the epoxidation reaction; the light brine of the bipolar membrane device 038 is concentrated by the concentrator IV 066 (reverse osmosis concentrator) and then processed by the bipolar membrane device 038 for recycling.

[0215] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0216] Run the experiment using the above system:

[0217] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0218] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0219] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0220] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0221] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0222] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0223] The acid outlet 039 of the bipolar membrane device 038 was sampled and analyzed as follows: PH < 2, CODcr = 12120 ppm, molybdenum element = 7122 ppm.

[0224] in conclusion:

[0225] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0226] 2. At the same time, since the molybdenum element is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and the organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly improved, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and then concentrated by the concentration device III 035 and treated by the bipolar membrane device 038, the proportion of molybdenum element in the obtained acid is increased again and the proportion of organic matter therein is reduced again, which is equivalent to separating organic matter and inorganic matter again. The acid outlet 039 of the bipolar membrane device 038 can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element (as a catalyst) is recovered and the organic impurities it carries are ensured to be less. Most of the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008 is discharged from the brine outlet 010 with low molybdenum content and the alkali outlet 041 of the bipolar membrane device 038, and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0227] Since Example 2 proves that the effects of the separation membrane system (nanofiltration membrane) and the electrical desalination system (electrodialysis equipment) are the same, it can be inferred that, on the basis of Example 7, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment) to produce the same effect.

[0228] Embodiment eight:

[0229] A depropanation tower effluent treatment system for a propylene oxide production process mainly comprises a depropanation tower 001, a scrubber Ⅰ002, a separation membrane system Ⅰ008 (including a high-pressure pump 007), a concentration device Ⅲ035 (a reverse osmosis concentration device, including a high-pressure pump 034), a bipolar membrane device 038, a concentration device Ⅳ066 (a reverse osmosis concentration device, including a high-pressure pump 065), an ammonia addition device Ⅰ042 (a stirred tank), a recovery tank 011 or an epoxidation reaction system 013.

[0230] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a high content of molybdenum. The brine outlet 009 and the brine outlet 010 with low molybdenum content, the brine outlet 009 with high molybdenum content of the separation membrane system I 008 is connected to the inlet of the high-pressure pump 034 of the concentrator III 035 (reverse osmosis concentrator), the outlet of the high-pressure pump 034 is connected to the water inlet of the concentrator III 035, the concentrator III 035 is provided with a concentrated liquid outlet 036 and a fresh water outlet 037, the concentrated liquid outlet 036 of the concentrator III 035 is connected to the water inlet of the bipolar membrane device 038, the bipolar membrane device 038 is provided with an alkali outlet 041, a salt water outlet 040, an acid outlet The brine outlet 040 of the bipolar membrane device 038 is connected to the inlet of the high-pressure pump 065 of the concentrator IV 066 (reverse osmosis concentrator), and the outlet of the high-pressure pump 065 is connected to the water inlet of the concentrator IV 066. The concentrator IV 066 (reverse osmosis concentrator) is also provided with a concentrate outlet 067 and a fresh water outlet 068. The concentrate outlet 067 of the concentrator IV 066 is connected to the water inlet of the bipolar membrane device 038; the acid outlet 039 of the bipolar membrane device 038 is connected to the water inlet of the ammonia adding device I 042 (stirring tank), and the ammonia adding device I 04 2 (stirred kettle) is also provided with an ammonia pipeline 043, the outlet of the ammonia adding device I 042 (stirred kettle) is connected to the water inlet of the delivery pump 044, the outlet of the delivery pump 044 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process, the epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, a discharge port 012, and the discharge port 012 of the epoxidation reactor 013 is connected to the depropanization tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanization tower of the propylene oxide production process).

[0231] The above processing system operates as follows:

[0232] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0233] The effluent from the effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, a water phase outlet 005 and an oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber Ⅰ002 is pressurized by a high-pressure pump 007 and then processed by a separation membrane system Ⅰ008 (nanofiltration membrane is selected), and the obtained brine with high molybdenum content is discharged. Port 009 is concentrated by concentrating device III 035 (reverse osmosis concentrating device), and then treated by bipolar membrane device 038. The acid produced by bipolar membrane device 038 is added with ammonia water by ammonia adding device I 042 (stirring kettle), and then pumped into recovery tank 011 for recovery by delivery pump 044, or enters epoxidation reaction system 013 for reuse in epoxidation reaction; the brine from bipolar membrane device 038 is concentrated by concentrating device IV 066 (reverse osmosis concentrating device), and then treated by bipolar membrane device 038 again for recycling.

[0234] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0235] Run the experiment using the above system:

[0236] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0237] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0238] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0239] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0240] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0241] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0242] The acid outlet 039 of the bipolar membrane device 038 was sampled and analyzed as follows: PH < 2, CODcr = 12120 ppm, molybdenum element = 7122 ppm.

[0243] After adding ammonia water through ammonia adding equipment Ⅰ042, sampling and analysis are as follows: PH = 7.6, molybdenum element = 6814 ppm.

[0244] in conclusion:

[0245] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0246] 2. At the same time, since the molybdenum element is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and the organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly improved, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and then concentrated by the concentration device III 035 and treated by the bipolar membrane device 038, the proportion of molybdenum element in the obtained acid is increased again and the proportion of organic matter therein is reduced again, which is equivalent to separating organic matter and inorganic matter again. The acid outlet 039 of the bipolar membrane device 038 is converted into an ammonium salt (such as ammonium dimolybdate) after passing through the ammonia addition device I 042, which is the same as the catalyst of the existing epoxidation reactor and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element is recovered (as a catalyst) and the organic impurities it carries are ensured to be less. Most of the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008 is discharged from the brine outlet 010 with low molybdenum content and the alkali outlet 041 of the bipolar membrane device 038, and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0247] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of this Example 8, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

[0248] Embodiment nine:

[0249] A depropanation tower effluent treatment system for a propylene oxide production process mainly comprises a depropanation tower 001, a scrubber Ⅰ 002, a separation membrane system Ⅰ 008 (including a high-pressure pump 007), a concentration device Ⅲ 035 (a reverse osmosis concentration device, including a high-pressure pump 034), a bipolar membrane device 038, a concentration device Ⅳ 066 (a reverse osmosis concentration device, including a high-pressure pump 065), an ammonia addition device Ⅰ 042 (a stirring kettle), an evaporator Ⅱ 045, a solid-liquid separation device Ⅱ (centrifuge) 047, a recovery tank 011 or an epoxidation reaction system 013.

[0250] The effluent outlet 006 (referring to the outlet of the bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with high molybdenum content of I008 is connected to the inlet of the high-pressure pump 034 of the concentrator III035 (reverse osmosis concentrator), and the outlet of the high-pressure pump 034 is connected to the water inlet of the concentrator III035. The concentrator III035 is provided with a concentrate outlet 036 and a fresh water outlet 037. The concentrate outlet 036 of the concentrator III035 is connected to the water inlet of the bipolar membrane device 038. The bipolar membrane device 038 is provided with an alkali outlet 041, a fresh water outlet 040, and an acid outlet 039. The fresh water outlet 040 of the bipolar membrane device 038 is connected to the inlet of the high-pressure pump 065 of the concentrator IV066 (reverse osmosis concentrator). The outlet of 065 is connected to the water inlet of the concentrator IV 066, and the concentrator IV 066 (reverse osmosis concentrator) is also provided with a concentrate outlet 067 and a fresh water outlet 068. The concentrate outlet 067 of the concentrator IV 066 is connected to the water inlet of the bipolar membrane device 038; the acid outlet 039 of the bipolar membrane device 038 is connected to the water inlet of the ammonia adding device I 042 (stirring kettle), and the ammonia adding device I 042 (stirring kettle) is also provided with an ammonia water pipeline 043, and the water outlet of the ammonia adding device I 042 (stirring kettle) is connected to the water inlet of the delivery pump 044, and the water outlet of the delivery pump 044 is connected to the water inlet of the evaporator II 045, and the evaporator II 045 is also provided with a re The outlet of the boiler 046 and the evaporator II 045 are connected to the inlet of the solid-liquid separation device II (centrifuge) 047, and the solid outlet 048 of the solid-liquid separation device II (centrifuge) 047 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process); the solid-liquid separation device II (centrifuge) 047 is also provided with a liquid outlet 049.

[0251] The above processing system operates as follows:

[0252] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0253] The effluent from the effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanization tower 001 (the present embodiment is a high-pressure depropanization tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber I 002 (the source is the alkali addition pipeline 003), and two products, the water phase outlet 005 and the oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber I 002 is pressurized by the high-pressure pump 007 and then processed by the separation membrane system I 008 (nanofiltration membrane is selected), and the obtained brine outlet 009 with a high molybdenum content is passed through the concentration device III 035 (reverse osmosis concentration) The acid produced by the bipolar membrane device 038 is concentrated by the ammonia device Ⅰ042 (stirring kettle), and then treated by the bipolar membrane device 038. The acid produced by the bipolar membrane device 038 is added with ammonia water by the ammonia device Ⅰ042 (stirring kettle), and then pumped into the evaporator Ⅱ045 for evaporation and concentration by the delivery pump 044. After that, the solid-liquid separation is carried out by the solid-liquid separation device Ⅱ (centrifuge) 047, and the solid enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 and is reused in the epoxidation reaction; the light brine of the bipolar membrane device 038 is concentrated by the concentration device Ⅳ066 (reverse osmosis concentration device) and then treated by the bipolar membrane device 038 for recycling.

[0254] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0255] Run the experiment using the above system:

[0256] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0257] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0258] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0259] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0260] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0261] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0262] The acid outlet 039 of the bipolar membrane device 038 was sampled and analyzed as follows: PH < 2, CODcr = 12120 ppm, molybdenum element = 7122 ppm.

[0263] After adding ammonia water through ammonia adding equipment Ⅰ042, sampling and analysis are as follows: PH = 7.6, molybdenum element = 6814 ppm.

[0264] After that, the solid was obtained by further evaporation and concentration in evaporator II 045 and treatment in solid-liquid separation equipment II (centrifuge) 047. The analysis result showed that the molybdenum content was 28.12%.

[0265] in conclusion:

[0266] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0267] 2. At the same time, since the molybdenum element is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and the organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly increased, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and then after being concentrated by the concentration device III 035 and treated by the bipolar membrane device 038, the proportion of molybdenum element in the obtained acid is further increased and the proportion of organic matter therein is The ratio is reduced again, which is equivalent to separating organic matter and inorganic matter again. The acid outlet 039 of the bipolar membrane device 038 converts the acid containing molybdenum element into the form of ammonium salt (e.g. ammonium dimolybdate) after passing through the ammonia adding device I 042, which is the same as the catalyst of the existing epoxidation reactor. Then, it is treated by the evaporator II 045 and the solid-liquid separation device II (centrifuge) 047 to obtain the solid in the form of ammonium salt of molybdenum element (e.g. ammonium dimolybdate), which avoids bringing water into the epoxidation reactor and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element (as a catalyst) is recovered and the organic impurities carried by it are ensured to be less. For the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008, most of it is discharged from the brine outlet 010 with low molybdenum content and the alkali outlet 041 of the bipolar membrane device 038, and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0268] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of Example 9, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

[0269] Embodiment ten:

[0270] A depropanation tower effluent treatment system for a propylene oxide production process mainly comprises a depropanation tower 001, a scrubber Ⅰ002, a separation membrane system Ⅰ008 (including a high-pressure pump 007), a concentration device Ⅲ035 (a reverse osmosis concentration device, including a high-pressure pump 034), an evaporator Ⅲ050, a solid-liquid separation device Ⅲ (centrifuge) 052, a recovery tank 011 or an epoxidation reaction system 013.

[0271] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of the separation membrane system Ⅰ008 is connected to the inlet of the high-pressure pump 034 of the concentrator III 035 (reverse osmosis concentrator), and the outlet of the high-pressure pump 034 is connected to the water inlet of the concentrator III 035. The concentrator III 035 is provided with a concentrated liquid outlet 036 and a fresh water outlet 037. The concentrated liquid outlet 036 of the concentrator III 035 is connected to the water inlet of the evaporator III 050. The evaporator III 050 is also provided with a reboiler 051. The outlet of the evaporator III 050 is connected to the inlet of the solid-liquid separation device III (centrifuge) 052. The solid outlet 053 of the solid-liquid separation device III (centrifuge) 052 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process); the solid-liquid separation device III (centrifuge) 052 is also provided with a liquid outlet 054.

[0272] The above processing system operates as follows:

[0273] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0274] The effluent from the effluent outlet 006 (referring to the bottom liquid outlet) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution by the scrubber Ⅰ002 (the source is the alkali addition pipeline 003), and two products, the aqueous phase outlet 005 and the oil phase outlet 004, are obtained. The aqueous phase of the aqueous phase outlet 005 of the scrubber Ⅰ002 is pressurized by the high-pressure pump 007 and then processed by the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The obtained brine outlet 009 with a high molybdenum content is concentrated by the concentrator Ⅲ035 (reverse osmosis concentrator), and then pumped into the evaporator Ⅲ050 for evaporation and concentration, and then separated by solid-liquid separation equipment Ⅲ (centrifuge) 052. The solid enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 for reuse in the epoxidation reaction.

[0275] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0276] Run the experiment using the above system:

[0277] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0278] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0279] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0280] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0281] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0282] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0283] Solid analysis of solid-liquid separation equipment III (centrifuge) 052 is as follows: Molybdenum content 12.35%

[0284] in conclusion:

[0285] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0286] 2. At the same time, since molybdenum is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum to the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly increased, that is, the molybdenum is purified (most of the organic matter and the molybdenum are separated), and then after being concentrated by the concentration device III 035, it is treated by the evaporator III 050 and the solid-liquid separation equipment III (centrifuge) 052 to obtain a solid containing molybdenum, which avoids the introduction of water into the epoxidation reactor and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum is recovered (as a catalyst) and the organic impurities carried by it are ensured to be less. As for the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008, most of it is discharged from the brine outlet 010 with a low molybdenum content and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0287] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of this Example 10, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

[0288] Embodiment eleven:

[0289] A depropylene tower effluent treatment system for a propylene oxide production process mainly comprises a depropylene tower 001, a scrubber Ⅰ 002, a separation membrane system Ⅰ 008 (including a high-pressure pump 007), a concentration device Ⅲ 035 (a reverse osmosis concentration device, including a high-pressure pump 034), an ammonia addition device Ⅱ 055 (a stirred tank), an evaporator Ⅳ 058, a solid-liquid separation device Ⅳ (centrifuge) 060, a recovery tank 011 or an epoxidation reaction system 013.

[0290] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ008, and the outlet of the high-pressure pump 007 is connected to the separation membrane system Ⅰ008 (nanofiltration membrane is selected). The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The brine outlet 009 with a high molybdenum content of the separation membrane system Ⅰ008 is connected to the inlet of the high-pressure pump 034 of the concentrator Ⅲ035 (reverse osmosis concentrator). The outlet of the high-pressure pump 034 is connected to the water inlet of the concentrator Ⅲ035. The concentrator Ⅲ035 is provided with a concentrate outlet 036 and a fresh water outlet 037. The concentrate outlet of the concentrator Ⅲ035 036 is connected to the water inlet of ammonia adding equipment II 055 (stirring kettle), ammonia adding equipment II 055 (stirring kettle) is also provided with an ammonia water pipeline 056, the water outlet of ammonia adding equipment II 055 (stirring kettle) is connected to the water inlet of a delivery pump 057, the water outlet of the delivery pump 057 is connected to the water inlet of an evaporator IV 058, the evaporator IV 058 is also provided with a reboiler 059, the outlet of the evaporator IV 058 is connected to the inlet of a solid-liquid separation equipment IV (centrifuge) 060, the solid-liquid separation equipment IV (centrifuge) 061 is connected to the water inlet of a delivery pump 057, the water outlet of the delivery pump 057 is connected to the water inlet of an evaporator IV 058, the evaporator IV 058 is also provided with a reboiler 059, the outlet of the evaporator IV 058 is connected to the inlet of a solid-liquid separation equipment IV (centrifuge) 060 0 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process. The epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012. The discharge port 012 of the epoxidation reactor 013 is connected to the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process); the solid-liquid separation equipment IV (centrifuge) 060 is also provided with a liquid outlet 062.

[0291] The above processing system operates as follows:

[0292] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0293] The effluent from the effluent outlet 006 (referring to the tower bottom liquid outlet) of the depropanation tower 001 (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution by the scrubber I 002 (the source is the alkali addition pipeline 003), and two outlets, a water phase outlet 005 and an oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber I 002 is pressurized by the high-pressure pump 007 and then processed by the separation membrane system I 008 (nanofiltration membrane is selected). The obtained brine outlet 009 with a high molybdenum content is concentrated by the concentrator III 035 (reverse osmosis concentrator), and then ammonia water is added to the ammonia adding device II 055 (stirring kettle), and then the ammonia is pumped into the evaporator IV 058 by the delivery pump 057 for evaporation and concentration, and then the solid-liquid separation device IV (centrifuge) 060 is separated into solid and liquid, and the solid enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 and is reused in the epoxidation reaction.

[0294] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0295] Run the experiment using the above system:

[0296] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0297] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0298] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0299] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0300] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0301] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0302] Solid analysis of solid-liquid separation equipment III (centrifuge) 052 is as follows: Molybdenum content 25.52%

[0303] in conclusion:

[0304] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0305] 2. At the same time, since the molybdenum element is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and the organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly improved, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and then after being concentrated by the concentration device III 035 and then by the ammonia addition device II 055, the acid containing the molybdenum element is converted into an ammonium salt (for example, ammonium dimolybdate) in the form of the same catalyst as the existing epoxidation reactor, and after being treated by the evaporator IV 058 and the solid-liquid separation device IV (centrifuge) 060, a solid containing the molybdenum element is obtained, which avoids the introduction of water into the epoxidation reactor and can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element (as a catalyst) is recovered and the organic impurities carried by it are ensured to be less. Most of the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008 is discharged from the brine outlet 010 with a low molybdenum content and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0306] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of this Example 11, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

[0307] Embodiment 12:

[0308] A depropylene tower effluent treatment system for a propylene oxide production process mainly comprises a depropylene tower 001, a scrubber Ⅰ 002, a separation membrane system Ⅰ 008 (including a high-pressure pump 007), a concentration device Ⅲ 035 (a reverse osmosis concentration device, including a high-pressure pump 034), a bipolar membrane device 038, a concentration device Ⅳ 066 (a reverse osmosis concentration device, including a high-pressure pump 065), an ammonia addition device Ⅰ 042 (a stirring kettle), an evaporator Ⅱ 045, a solid-liquid separation device Ⅱ (centrifuge) 047, a mixing tank 063, a recovery tank 011 or an epoxidation reaction system 013.

[0309] The effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 of the propylene oxide production process (the present embodiment is a high-pressure depropanation tower of the propylene oxide production process) is connected to the inlet of the scrubber Ⅰ002, and the scrubber Ⅰ002 is also provided with an alkali addition pipeline 003, an aqueous phase outlet 005, and an oil phase outlet 004. The aqueous phase outlet 005 of the scrubber Ⅰ002 is connected to the inlet of the high-pressure pump 007 of the separation membrane system Ⅰ (nanofiltration membrane is selected) 008, and the outlet of the high-pressure pump 007 is connected to the water inlet of the separation membrane system Ⅰ008. The separation membrane system Ⅰ008 is also provided with a brine outlet 009 with a high molybdenum content and a brine outlet 010 with a low molybdenum content. The molybdenum content of the separation membrane system Ⅰ008 is 009. The high-volume salt water outlet 009 is connected to the inlet of the high-pressure pump 034 of the concentrating device III 035 (reverse osmosis concentrating device), the outlet of the high-pressure pump 034 is connected to the water inlet of the concentrating device III 035, the concentrating device III 035 is provided with a concentrate outlet 036 and a fresh water outlet 037, the concentrate outlet 036 of the concentrating device III 035 is connected to the water inlet of the bipolar membrane device 038, the bipolar membrane device 038 is provided with an alkali outlet 041, a salt water outlet 040, and an acid outlet 039, the salt water outlet 040 of the bipolar membrane device 038 is connected to the inlet of the high-pressure pump 065 of the concentrating device IV 066 (reverse osmosis concentrating device), the outlet of the high-pressure pump 065 is connected to the water inlet of the concentrating device IV 066 The concentrator IV 066 (reverse osmosis concentrator) is also provided with a concentrate outlet 067 and a fresh water outlet 068. The concentrate outlet 067 of the concentrator IV 066 is connected to the water inlet of the bipolar membrane device 038; the acid outlet 039 of the bipolar membrane device 038 is connected to the water inlet of the ammonia adding device I 042 (stirring kettle). The ammonia adding device I 042 (stirring kettle) is also provided with an ammonia water pipeline 043. The water outlet of the ammonia adding device I 042 (stirring kettle) is connected to the water inlet of the delivery pump 044. The water outlet of the delivery pump 044 is connected to the water inlet of the evaporator II 045. The evaporator II 045 is also provided with a reboiler 046. The outlet of the evaporator II 045 is connected to the solid-liquid separation device II (centrifugal separation device). The inlet of the solid-liquid separation device II (centrifuge) 047 is connected to the solid outlet 048 of the solid-liquid separation device II (centrifuge) 047 is connected to the inlet of the mixing tank 063, the mixing tank 063 is also provided with an inlet 064, the outlet of the mixing tank 063 is connected to the recovery tank 011 or the inlet of the epoxidation reactor 013 of the propylene oxide production process, the epoxidation reactor 013 is also provided with a propylene inlet 014, an EBHP (ethylbenzene hydroperoxide) inlet 015, and a discharge port 012, the discharge port 012 of the epoxidation reactor 013 is connected to the depropanation tower 001 of the propylene oxide production process (this embodiment is a high-pressure depropanation tower of the propylene oxide production process); the solid-liquid separation device II (centrifuge) 047 is also provided with a liquid outlet 049.

[0310] The above processing system operates as follows:

[0311] The target substance treated in this embodiment is the effluent from the depropanation tower of the propylene oxide production process, which is the solution at the bottom liquid outlet of the depropanation tower 001 (high-pressure depropanation tower) of the propylene oxide production process, and mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances).

[0312] The effluent from the effluent outlet 006 (referring to the outlet of the tower bottom liquid) of the depropanation tower 001 (this embodiment is a high-pressure depropanation tower of the propylene oxide production process) of the propylene oxide production process is washed with alkali solution in the scrubber I 002 (the source is the alkali addition pipeline 003), and two products, namely, the water phase outlet 005 and the oil phase outlet 004, are obtained. The water phase of the water phase outlet 005 of the scrubber I 002 is pressurized by the high-pressure pump 007 and then processed by the separation membrane system I 008 (nanofiltration membrane is selected). The brine outlet 009 with a high molybdenum content is concentrated by the concentrator III 035 (reverse osmosis concentrator), and then passes through the bipolar membrane device 0 38 treatment, the acid produced by the bipolar membrane device 038 is added with ammonia water by the ammonia device Ⅰ042 (stirring kettle), and then pumped into the evaporator Ⅱ045 for evaporation and concentration by the delivery pump 044, and then separated by solid-liquid separation equipment Ⅱ (centrifuge) 047, and the solid enters the mixing tank 063, and after adding chemicals from the inlet '064 of the mixing tank 063, it enters the recovery tank 011 for recovery, or enters the epoxidation reaction system 013 and is reused in the epoxidation reaction; the light brine of the bipolar membrane device 038 is concentrated by the concentration device Ⅳ066 (reverse osmosis concentration device) and then processed by the bipolar membrane device 038 again for recycling.

[0313] The epoxidation reaction system 013 described in all embodiments of the utility model refers to an epoxidation reactor. In the epoxidation reaction system (epoxidation reactor), in the presence of a molybdenum-based catalyst (such as ammonium dimolybdate), propylene and EBHP undergo a liquid-phase epoxidation reaction to generate propylene oxide (PO) and MBA, propylene + EBHP → PO + MBA. Therefore, the material components discharged from the epoxidation reactor to the decarboxylation tower 001 (high-pressure decarboxylation tower) are mainly PO, MBA, unreacted propylene (need to be removed), etc., and molybdenum-containing inorganic substances (as the catalyst of the epoxidation reactor, the purpose of the design of the utility model is to recover this part of the molybdenum-containing inorganic substances). The decarboxylation tower discharge liquid (tower bottom liquid) obtained by treatment of the decarboxylation tower 001 (high-pressure decarboxylation tower) mainly contains PO (propylene oxide), MBA, propylene, etc., and molybdenum-containing inorganic substances.

[0314] Run the experiment using the above system:

[0315] The water phase outlet 005 of scrubber Ⅰ002 was sampled and analyzed as follows: black color, PH=12.19, conductivity=225ms / cm, CODcr=152100ppm, molybdenum element=1190ppm.

[0316] The water volume of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 accounts for about 10% of the water inlet of the separation membrane system I (nanofiltration membrane) 008. The sampling and analysis of the brine outlet 009 with high molybdenum content of the separation membrane system I (nanofiltration membrane) 008 are as follows: PH = 12.33, CODcr = 121900ppm, molybdenum element = 10215ppm.

[0317] That is, after being processed by the separation membrane system I (nanofiltration membrane) 008, the brine outlet 009 with a high molybdenum content is obtained:

[0318] The total amount of molybdenum in the influent water = 10215ppm × 10% ÷ 1190ppm = 86%;

[0319] The total amount of organic matter accounts for 8% of the total amount of organic matter in the influent water = 121900ppm × 10% ÷ 152100ppm = 8%.

[0320] The concentrated liquid outlet 036 of the concentration device III 035 was sampled and analyzed as follows: PH = 12.56, CODcr = 301560 ppm, molybdenum element = 26513 ppm.

[0321] The acid outlet 039 of the bipolar membrane device 038 was sampled and analyzed as follows: PH < 2, CODcr = 12120 ppm, molybdenum element = 7122 ppm.

[0322] After adding ammonia water through ammonia adding equipment Ⅰ042, sampling and analysis are as follows: PH = 7.6, molybdenum element = 6814 ppm.

[0323] After that, the solid was obtained by further evaporation and concentration in evaporator II 045 and treatment in solid-liquid separation equipment II (centrifuge) 047. The analysis result showed that the molybdenum content was 28.12%.

[0324] Ethylbenzene and isooctanoic acid were added into the mixing tank 063, and then the molybdenum content in the mixing tank 063 was tested to be 7.56%.

[0325] in conclusion:

[0326] 1. In the brine outlet 009 with high molybdenum content, the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) is significantly improved compared with the ratio of the total amount of molybdenum element: the total amount of organic matter (characterized by COD) in the inlet water of the separation membrane system I (nanofiltration membrane) 008, which is equivalent to a good separation of inorganic and organic matter containing molybdenum, which is beneficial to reduce the proportion of organic impurities in inorganic matter containing molybdenum.

[0327] 2. At the same time, since the molybdenum element is valuable (catalyst) for the epoxidation reaction system 013 (epoxidation reactor), and the organic matter is an impurity for the epoxidation reaction system 013 (epoxidation reactor), that is, after being treated by the separation membrane system I (nanofiltration membrane) 008, the ratio of the total amount of molybdenum element: the total amount of organic matter in the brine outlet 009 with a high molybdenum content is significantly improved, that is, the molybdenum element is purified (most of the organic matter and the molybdenum element are separated), and then after being concentrated by the concentration device III 035 and treated by the bipolar membrane device 038, the proportion of molybdenum element in the obtained acid is further increased and the proportion of organic matter therein is further reduced, which is equivalent to another separation. Organic matter, inorganic matter, the acid outlet 039 of the bipolar membrane device 038 is converted into the form of ammonium salt (such as ammonium dimolybdate) after passing through the ammonia adding device I 042, which is the same as the catalyst of the existing epoxidation reactor, and then processed by the evaporator II 045 and the solid-liquid separation device II (centrifuge) 047 to obtain the solid in the form of ammonium salt (such as ammonium dimolybdate) of the molybdenum element, avoiding the introduction of water into the epoxidation reactor, and then put into ethylbenzene and isooctanoic acid through the mixing tank 063, which is the same as the existing catalyst configuration method, and then can be reused in the epoxidation reaction system 013 (epoxidation reactor), that is, the molybdenum element (as a catalyst) is recovered and the organic impurities carried by it are ensured to be less. For the organic matter in the influent of the separation membrane system I (nanofiltration membrane) 008, most of it is discharged from the brine outlet 010 with low molybdenum content and the alkali outlet 041 of the bipolar membrane device 038, and is not recovered to the epoxidation reaction system 013 (epoxidation reactor).

[0328] Since Example 2 proves that the effects of the separation membrane system I (nanofiltration membrane) 008 and the electrical desalination system I 016 (electrodialysis equipment is selected) are the same, it can be inferred that on the basis of this Example 12, the separation membrane system I (nanofiltration membrane) 008 is replaced with the electrical desalination system I 016 (electrodialysis equipment is selected) to produce the same effect.

Claims

1. A treatment system for the effluent from a depropylene tower in a propylene oxide production process, characterized in that: The treatment system comprises: a depropanol tower, a scrubber I, and a separation membrane system I or an electric desalination system I; The outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber I, and the water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I; Or the outlet of the depropanation tower discharge liquid is connected to the inlet of the scrubber I, and the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I.

2. The processing system according to claim 1, characterized in that The water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, and the brine outlet with high molybdenum content of the separation membrane system I is connected to the inlet of the epoxidation reaction system or the recovery tank; Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, and the brine outlet with high molybdenum content of the electric desalination system I is connected to the inlet or recovery tank of the epoxidation reaction system.

3. The processing system according to claim 2, characterized in that It is also equipped with separation membrane system II, electric desalination system II, separation membrane system III or electric desalination system III. The water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, the brine outlet with high molybdenum content of the separation membrane system I is connected to the water inlet of the electric desalination system II, and the brine outlet with high molybdenum content of the electric desalination system II is connected to the inlet of the epoxidation reaction system or the recovery tank; Or the water phase outlet of the scrubber I is connected to the water inlet of the separation membrane system I, the brine outlet with high molybdenum content of the separation membrane system I is connected to the water inlet of the separation membrane system II, and the brine outlet with high molybdenum content of the separation membrane system II is connected to the inlet of the epoxidation reaction system or the recovery tank; Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, the brine outlet with high molybdenum content of the electric desalination system I is connected to the water inlet of the separation membrane system III, and the brine outlet with high molybdenum content of the separation membrane system III is connected to the inlet of the epoxidation reaction system or the recovery tank; Or the water phase outlet of the scrubber I is connected to the water inlet of the electric desalination system I, the brine outlet with high molybdenum content of the electric desalination system I is connected to the water inlet of the electric desalination system III, and the brine outlet with high molybdenum content of the electric desalination system III is connected to the inlet of the epoxidation reaction system or the recovery tank.

4. The processing system according to claim 1, 2 or 3, characterized in that An oil removal device is provided between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oil removal device is provided between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oxidizing elimination device is provided between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidizing elimination device is provided between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oil removal device and an oxidizing elimination device are provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oil removal device and an oxidizing elimination device are provided in sequence between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I; or an oxidizing elimination device and an oil removal device are provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidizing elimination device and an oil removal device are provided in sequence between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I; or an oxidizing elimination device and an oil removal device are provided in sequence between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I.

5. The processing system according to claim 4, characterized in that The oil removal device includes at least one of an oil-water stratification device, a rotary stratification device, an air flotation device, an oil separation device, an oil scraping device, an oil film removal device, an air blowing deoiling and volatilization device or an oil dissolving device.

6. The processing system according to claim 5, characterized in that The oil dissolving device is also connected to an alkali adding pipeline or an emulsifier pipeline.

7. The processing system according to claim 2 or 3, characterized in that: The outlet of the brine with high molybdenum content of the separation membrane system I to the inlet of the epoxidation reaction system, the outlet of the brine with high molybdenum content of the electrical desalination system I to the inlet of the epoxidation reaction system, the outlet of the brine with high molybdenum content of the separation membrane system II to the inlet of the epoxidation reaction system, the outlet of the brine with high molybdenum content of the electrical desalination system II to the inlet of the epoxidation reaction system, the outlet of the brine with high molybdenum content of the separation membrane system III to the inlet of the epoxidation reaction system, the outlet of the brine with high molybdenum content of the electrical desalination system III to the inlet of the epoxidation reaction system, the molybdenum element of the separation membrane system I A bipolar membrane device is provided between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electric desalination system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the electric desalination system III and the inlet of the recovery tank, or an evaporator III and a solid-liquid separation device III, or an ammonia addition device II, or an incineration device; The brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the water inlet of the bipolar membrane device, and the acid outlet of the bipolar membrane device is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III, or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the evaporator I, the outlet of the evaporator I is connected to the inlet of the solid-liquid separation device I, and the solid outlet of the solid-liquid separation device I is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the ammonia addition device I, and the water outlet of the ammonia addition device I is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III, or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the bipolar membrane device, the acid outlet of the bipolar membrane device is connected to the water inlet of the ammonia addition device I, the water outlet of the ammonia addition device I is connected to the water inlet of the evaporator II, the outlet of the evaporator II is connected to the inlet of the solid-liquid separation device II, and the solid outlet of the solid-liquid separation device II is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III, or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the evaporator III, the outlet of the evaporator III is connected to the inlet of the solid-liquid separation device III, and the solid outlet of the solid-liquid separation device III is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the ammonia addition device II, and the water outlet of the ammonia addition device II is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III, or the brine outlet with high molybdenum content of the electrical desalination system III is connected to the water inlet of the ammonia addition device II, the water outlet of the ammonia addition device II is connected to the water inlet of the evaporator IV, the outlet of the evaporator IV is connected to the inlet of the solid-liquid separation device IV, and the solid outlet of the solid-liquid separation device IV is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank; Or, the brine outlet with high molybdenum content of the separation membrane system I, the brine outlet with high molybdenum content of the electrical desalination system I, the brine outlet with high molybdenum content of the separation membrane system II, the brine outlet with high molybdenum content of the electrical desalination system II, the brine outlet with high molybdenum content of the separation membrane system III or the brine outlet with high molybdenum content of the electrical desalination system III are connected to the inlet of the incineration equipment, and the solid outlet of the incineration equipment is connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank.

8. The processing system according to claim 7, characterized in that The ammonia adding device I or the ammonia adding device II is connected to an ammonia water pipeline; And / or, the acid outlet of the bipolar membrane device, the water outlet of the ammonia addition device I, the water outlet of the ammonia addition device II, the solid outlet of the solid-liquid separation device I, the solid outlet of the solid-liquid separation device II, the solid outlet of the solid-liquid separation device III, the solid outlet of the solid-liquid separation device IV or the solid outlet of the incineration device are first connected to the inlet of the mixer or the inlet of the mixing tank, and the outlet of the mixer or the outlet of the mixing tank is then connected to the inlet of the epoxidation reaction system or the inlet of the recovery tank.

9. The processing system according to claim 1, 2 or 3, characterized in that: The brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are connected to at least one of a wet oxidation device, a sewage biochemical treatment device and an incineration device; Or the brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are connected to the water inlet of the wet oxidation device, and the water outlet of the wet oxidation device is connected to the sewage biochemical treatment device.

10. The processing system according to claim 9, characterized in that There is also a concentration device I; The brine outlet with low molybdenum content of the separation membrane system I, the brine outlet with low molybdenum content of the separation membrane system II, the brine outlet with low molybdenum content of the separation membrane system III, the brine outlet with low molybdenum content of the electric desalination system I, the brine outlet with low molybdenum content of the electric desalination system II or the brine outlet with low molybdenum content of the electric desalination system III are first connected to the water inlet of the concentrator I, and the fresh water outlet or the concentrated liquid outlet of the concentrator I is then connected to at least one of the wet oxidation device, the sewage biochemical treatment device, and the incineration equipment.

11. The processing system according to claim 1, 2 or 3, characterized in that There is also a concentration device II; The concentrating device II is arranged between the water phase outlet of the scrubber I and the water inlet of the separation membrane system I, and between the water phase outlet of the scrubber I and the water inlet of the electric desalination system I.

12. The processing system according to claim 4, characterized in that There is also a concentration device II; The concentrating device II is arranged between the water phase outlet of the scrubber I and the water inlet of the oil removal device, between the oil removal device and the water inlet of the separation membrane system I, between the oil removal device and the water inlet of the electric desalination system I, between the water phase outlet of the scrubber I and the water inlet of the deoxidation device, between the deoxidation device and the water inlet of the separation membrane system I, between the deoxidation device and the water inlet of the electric desalination system I, between the oil removal device and the water inlet of the deoxidation device, and between the deoxidation device and the water inlet of the oil removal device.

13. The processing system according to claim 2 or 3, characterized in that: There is also a concentration device II; The concentrating device II is arranged between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the epoxidation reaction system, and between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the recovery tank.

14. The processing system according to claim 3, characterized in that There is also a concentration device II; The concentrating device II is arranged between the outlet of the brine with high molybdenum content of the separation membrane system I and the water inlet of the separation membrane system II, between the outlet of the brine with high molybdenum content of the separation membrane system I and the water inlet of the electric desalination system II, between the outlet of the brine with high molybdenum content of the electric desalination system I and the water inlet of the separation membrane system III, between the outlet of the brine with high molybdenum content of the electric desalination system I and the water inlet of the electric desalination system III, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the epoxidation reaction system, and between the outlet of the brine with high molybdenum content of the electric desalination system II and the water inlet of the epoxidation reaction system. between the inlet of the oxidizing reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system III to the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system III to the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system II to the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electric desalination system II to the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system III to the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the electric desalination system III to the inlet of the recovery tank.

15. The processing system according to claim 7, characterized in that There is also a concentration device II; The concentrating device II is arranged between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the separation membrane system I and the water inlet of the separation membrane system II, between the outlet of the brine with high molybdenum content of the separation membrane system I and the water inlet of the electric desalination system II, between the outlet of the brine with high molybdenum content of the electric desalination system I and the water inlet of the separation membrane system III, and between the outlet of the brine with high molybdenum content of the electric desalination system I and the water inlet of the electric desalination system III between the water inlets of the separation membrane system II and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electrical desalination system II and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system III and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the electrical desalination system III and the inlet of the epoxidation reaction system, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the recovery tank, between the outlet of the brine with high molybdenum content of the electrical desalination system II and the inlet of the recovery tank, or between the outlet of the brine with high molybdenum content of the electrical desalination system III and the inlet of the recovery tank.

16. The processing system according to claim 7, characterized in that There is also a concentration device III; The concentrating device III is arranged between the brine outlet with high molybdenum content of the separation membrane system I and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system II and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system II and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system III and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the electric desalination system III and the water inlet of the bipolar membrane device, between the brine outlet with high molybdenum content of the separation membrane system I and the evaporating device. between the water inlet of the device III, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system II and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the electric desalination system II and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system III and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the electric desalination system III and the water inlet of the evaporator III, between the brine outlet with high molybdenum content of the separation membrane system I and the water inlet of the ammonia addition device II, between the brine outlet with high molybdenum content of the electric desalination system I and the water inlet of the ammonia addition device II between the outlet of the brine with high molybdenum content of the separation membrane system II and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the electric desalination system II and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the separation membrane system III and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the electric desalination system III and the water inlet of the ammonia adding device II, between the outlet of the brine with high molybdenum content of the separation membrane system I and the inlet of the incineration device, between the outlet of the brine with high molybdenum content of the electric desalination system I and the inlet of the incineration device, between the outlet of the brine with high molybdenum content of the separation membrane system II and the inlet of the incineration device, between the brine outlet with high molybdenum content of the salt system II and the inlet of the incineration equipment, between the brine outlet with high molybdenum content of the separation membrane system III and the inlet of the incineration equipment, between the brine outlet with high molybdenum content of the electric desalination system III and the inlet of the incineration equipment, between the acid outlet of the bipolar membrane device and the inlet of the epoxidation reaction system, between the acid outlet of the bipolar membrane device and the inlet of the recovery tank, between the acid outlet of the bipolar membrane device and the water inlet of the evaporator I, between the acid outlet of the bipolar membrane device and the water inlet of the ammonia addition device I, between the water outlet of the ammonia addition device I and the inlet of the epoxidation reaction system, between the water outlet of the ammonia addition device I and the inlet of the recovery tank,Between the water outlet of the ammonia adding equipment I and the water inlet of the evaporator II, between the water outlet of the ammonia adding equipment II and the inlet of the epoxidation reaction system, or between the water outlet of the ammonia adding equipment II and the inlet of the recovery tank, between the water outlet of the ammonia adding equipment II and the water inlet of the evaporator IV.

17. The processing system according to claim 8, characterized in that There is also a concentration device III; The concentrating device III is arranged between the acid outlet of the bipolar membrane device and the inlet of the mixer, between the water outlet of the ammonia adding device I and the inlet of the mixer, between the water outlet of the ammonia adding device II and the inlet of the mixer, between the acid outlet of the bipolar membrane device and the inlet of the mixing tank, between the water outlet of the ammonia adding device I and the inlet of the mixing tank, or between the water outlet of the ammonia adding device II and the inlet of the mixing tank.

18. The processing system according to claim 1, 2, 3 or 12, characterized in that The scrubber I is also provided with an alkali adding pipeline and / or a water adding pipeline.

19. The processing system according to claim 4, characterized in that The scrubber I is also provided with an alkali adding pipeline and / or a water adding pipeline.

20. The processing system according to claim 11, characterized in that The scrubber I is also provided with an alkali adding pipeline and / or a water adding pipeline.

21. The processing system according to claim 1, characterized in that There is also a scrubber II. The outlet of the depropanation tower discharge liquid is connected to the inlet of the scrubber II, the liquid outlet or the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber II is also provided with an alkali adding pipeline and / or a water adding pipeline; Or the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the liquid outlet or oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber I is further provided with an alkali adding pipeline and / or a water adding pipeline; the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline; Or the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber II is further provided with an alkali adding pipeline and / or a water adding pipeline; the water phase outlet of the scrubber II is connected to the water inlet of the separation membrane system I or the water inlet of the electric desalination system I; Or the outlet of the depropanol tower discharge liquid is connected to the inlet of the scrubber II, the oil phase outlet of the scrubber II is connected to the inlet of the scrubber I, and the scrubber I is also provided with an alkali addition pipeline and / or a water addition pipeline; the scrubber II is also provided with an alkali addition pipeline and / or a water addition pipeline; the water phase outlet of the scrubber II is connected to the water inlet of the separation membrane system I or the water inlet of the electric desalination system I.

22. The processing system according to claim 1 or 21, characterized in that A flash tank is also provided between the outlet of the depropanol tower discharge liquid and the inlet of the scrubber I; Alternatively, a flash tank and a cooler are provided between the outlet of the depropanol tower discharge liquid and the inlet of the scrubber I, the outlet of the depropanol tower discharge liquid is connected to the inlet of the flash tank, the liquid phase outlet of the flash tank is connected to the inlet of the cooler, and the outlet of the cooler is connected to the inlet of the scrubber I.

23. The processing system according to claim 21, characterized in that A flash tank is also provided between the outlet of the depropanation tower discharge liquid and the inlet of the scrubber II; Alternatively, a flash tank and a cooler are provided between the outlet of the depropanization tower discharge liquid and the inlet of the scrubber II, the outlet of the depropanization tower discharge liquid is connected to the inlet of the flash tank, the liquid phase outlet of the flash tank is connected to the inlet of the cooler, and the outlet of the cooler is connected to the inlet of the scrubber II.

24. The processing system of claim 1, 2, 3, 10, 12, 14, 15, 16 or 21, wherein: The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

25. The processing system according to claim 4, characterized in that The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

26. The processing system according to claim 7, characterized in that The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

27. The processing system according to claim 9, characterized in that The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

28. The processing system according to claim 11, characterized in that The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

29. The processing system according to claim 13, characterized in that The separation membrane system I adopts a nanofiltration membrane system; Or the electrical desalination system I adopts an electrodialysis device.

30. The processing system of claim 3, 10, 14, 15 or 16, wherein: The separation membrane system II or the separation membrane system III adopts a nanofiltration membrane system; Or the electrical desalination system II or the electrical desalination system III adopts electrodialysis equipment.

31. The processing system according to claim 7, characterized in that The separation membrane system II or the separation membrane system III adopts a nanofiltration membrane system; Or the electrical desalination system II or the electrical desalination system III adopts electrodialysis equipment.

32. The processing system according to claim 9, characterized in that The separation membrane system II or the separation membrane system III adopts a nanofiltration membrane system; Or the electrical desalination system II or the electrical desalination system III adopts electrodialysis equipment.

33. The processing system according to claim 1, 21 or 23, characterized in that The depropanation tower is connected to the epoxidation reaction system of the propylene oxide production process; Or the depropanation tower is a high-pressure depropanation tower in a propylene oxide production process; Or the outlet of the depropanation tower discharge liquid is the outlet of the bottom liquid of the depropanation tower; Or the depropanization tower is a high-pressure depropanization tower in a propylene oxide production process, and the outlet of the depropanization tower discharge liquid is the outlet of the bottom liquid of the high-pressure depropanization tower.

34. The processing system of claim 22, wherein: The depropanation tower is connected to the epoxidation reaction system of the propylene oxide production process; Or the depropanation tower is a high-pressure depropanation tower in a propylene oxide production process; Or the outlet of the depropanation tower discharge liquid is the outlet of the bottom liquid of the depropanation tower; Or the depropanization tower is a high-pressure depropanization tower in a propylene oxide production process, and the outlet of the depropanization tower discharge liquid is the outlet of the bottom liquid of the high-pressure depropanization tower.

35. The processing system of claim 1, 2, 3, 12, 19, 20 or 21, wherein: The oil phase outlet of the scrubber I is connected to the inlet of the low-pressure desorbing tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of the low-pressure desorbing tower.

36. The processing system according to claim 4, characterized in that The oil phase outlet of the scrubber I is connected to the inlet of the low-pressure desorbing tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of the low-pressure desorbing tower.

37. The processing system according to claim 11, characterized in that The oil phase outlet of the scrubber I is connected to the inlet of the low-pressure desorbing tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of the low-pressure desorbing tower.

38. The processing system according to claim 18, characterized in that The oil phase outlet of the scrubber I is connected to the inlet of the low-pressure desorbing tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of the low-pressure desorbing tower.

39. The processing system of claim 22, wherein: The oil phase outlet of the scrubber I is connected to the inlet of the low-pressure desorbing tower, or the oil phase outlet of the scrubber I is first connected to an oil-water separation device, and the oil phase outlet of the oil-water separation device is connected to the inlet of the low-pressure desorbing tower.

40. The processing system according to claim 21 or 23, characterized in that The oil phase outlet of the scrubber II is connected to the inlet of a low-pressure desorbing tower, or the oil phase outlet of the scrubber II is first connected to an oil-water separator, and the oil phase outlet of the oil-water separator is connected to the inlet of a low-pressure desorbing tower.

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