Oxidized tail gas treatment method and system

Abstract

The invention provides an oxidation tail gas treatment method and system. The oxidized tail gas treatment method comprises the steps that oxidized tail gas is subjected to membrane separation, and an organic composite silicon membrane is adopted for membrane separation; the organic composite silicon film comprises a base film and an organic silicon film, and the organic silicon film comprises an organic silicon polymer and a hydrophobic additive. The method has the advantages of being simple in technological process, low in investment, environmentally friendly, low in carbon emission, stable in operation and good in economic benefit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tail gas recovery, in particular to an oxidation tail gas treatment method and system. BACKGROUND

[0002] It is known that a large amount of tail gas and waste gas rich in VOCs and other organic gases is generated in the production, storage and transportation of chemical products. If these organic gases are directly discharged, environmental pollution will be caused. In recent years, with the increasing requirements of energy saving and environmental protection and the increasing requirements of improving the utilization rate of product added value of chemical devices, how to treat and recover these organic gases has become a research hotspot. The benzene phenol acetone production device adopts cumene oxidation method to produce cumene hydroperoxide. Cumene is oxidized to generate cumene hydroperoxide (CHP) under certain temperature and pressure. Oxidation tail gas (organic waste gas) is generated in the production process. The main component is cumene, and it also contains trace amounts of organic substances such as alcohol, ketone, acid and non-aromatic hydrocarbons and other harmful substances. If it is directly discharged, it will seriously pollute the environment. These oxidation tail gas containing organic substances can only be treated by condensation, catalytic combustion, adsorption and other methods to meet the emission standards.

[0003] In the prior art, the three methods of condensation, catalytic combustion and adsorption of activated carbon or the combination of the three methods are usually applied to the treatment of organic gases. However, the catalytic combustion method will produce more carbon dioxide, which does not meet the current carbon emission requirements. Although the adsorption method can meet the requirements, it needs to be replaced frequently due to the limitation of the adsorption capacity of the adsorbent, and the regeneration and replacement of the adsorbent will also cause great economic and environmental problems. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provides an oxidation tail gas treatment method and system.

[0005] In a first aspect, the present application provides an oxidation tail gas treatment method, comprising: subjecting the oxidation tail gas to membrane separation, wherein the membrane separation adopts an organic composite silicon membrane; the organic composite silicon membrane comprises a base film and an organic silicon membrane, and the organic silicon membrane comprises an organic silicon polymer and a hydrophobic additive.

[0006] In some embodiments, the oxidation tail gas is the tail gas generated in the reaction of preparing phenol and / or acetone by oxidizing cumene.

[0007] By the reaction of cumene oxidation method, cumene is oxidized to generate cumene hydroperoxide (CHP) under certain temperature and pressure. Tail gas (organic waste gas) is generated in the production process. The main component is cumene, and it also contains trace amounts of organic substances such as alcohol, ketone, acid and non-aromatic hydrocarbons and other harmful substances.

[0008] In some embodiments, the content of organic matter in the oxidation tail gas is 100-15000 g / m 3 .

[0009] In some embodiments, the oxidation tail gas treatment method further comprises cooling the oxidation tail gas before the membrane separation.

[0010] In some embodiments, the cooling temperature is 0-60℃, for example, 0℃, 10℃, 15℃, 20℃, 25℃, 30℃, 40℃, 50℃, or 60℃.

[0011] In some embodiments, the cooling temperature is 10-30℃.

[0012] In some embodiments, the oxidation tail gas treatment method further comprises adsorbing the oxidation tail gas after the membrane separation.

[0013] In some embodiments, the oxidation tail gas treatment method comprises:

[0014] (1) oxidizing cumene to obtain an oxidation tail gas, cooling the oxidation tail gas, and performing gas-liquid separation to obtain liquefied organic matter and tail gas;

[0015] (2) performing the membrane separation on the tail gas obtained in step (1) to obtain oxidation tail gas after membrane separation and tail gas containing organic matter;

[0016] (3) adsorbing the oxidation tail gas after membrane separation;

[0017] (4) recovering the organic matter from the tail gas containing organic matter in step (2) and the tail gas after adsorption in step (3).

[0018] In step (1), the main component of the liquefied organic matter is cumene.

[0019] In step (3), the concentration of organic matter in the oxidation tail gas after membrane separation and adsorption separation is less than 50 ppm, reaching the emission standard, which can be directly discharged (such as through a chimney to the atmosphere) or recycled (such as the tail gas after adsorption separation is mixed with oxygen-rich air, compressed to 0.3 MPa, and then mixed with fresh air as the oxidation raw gas).

[0020] After the oxidation tail gas after membrane separation is saturated by the adsorption unit, it can be regenerated by hot air or water vapor. The adsorbed organic matter in the adsorbent is entrained by the regeneration gas, and after condensation, the liquefied organic matter can be recovered. The adsorbent can be reused after regeneration.

[0021] In some embodiments, the pressure of the feed end of the membrane separation is 0.3-0.6 MPa, for example 0.3 MPa, 0.4 MPa, 0.6 MPa or 0.5 MPa.

[0022] In some embodiments, the temperature of the membrane separation is 0-60℃, for example 0℃, 10℃, 15℃, 20℃, 25℃, 30℃, 40℃, 50℃, 60℃.

[0023] In some embodiments, the temperature of the membrane separation is 10-30℃.

[0024] The temperature and pressure of the membrane separation should not be too high, as too high temperature or pressure will affect the membrane separation effect. The pressure and temperature of the membrane separation are basically the same as the tail gas temperature and pressure of the gas-liquid separation tower.

[0025] In some embodiments, the hydrophobic additive is one or more of ultra-fine graphene, white carbon black or carbon nanotubes.

[0026] In some embodiments, the particle size of the hydrophobic additive is 0.3-50 nm, for example 0.3 nm, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0027] In some embodiments, the particle size of the hydrophobic additive is 0.5-20 nm.

[0028] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon polymer is 1:(10-1000), for example 1:10, 1:30, 1:50, 1:70, 1:90, 1:110, 1:130, 1:150, 1:170, 1:190, 1:200, 1:250, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:1000.

[0029] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-300).

[0030] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-200).

[0031] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-100).

[0032] In some embodiments, the method for preparing the organosilicon membrane comprises mixing an organosilicon sol with a hydrophobic additive and heating to obtain the organosilicon membrane.

[0033] In some embodiments, the heating temperature is 20-100°C, for example 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C.

[0034] In some embodiments, the heating temperature in step (1) is 40-90°C.

[0035] In some embodiments, the heating time is 0.1-4h, for example 0.1h, 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h.

[0036] In some embodiments, the heating time is 0.2-1h.

[0037] In some embodiments, the method for preparing the silicone sol comprises mixing a silicone source precursor, an alcohol, deionized water and a catalyst, and performing a hydrolysis polymerization reaction.

[0038] In some embodiments, the hydrolysis polymerization reaction temperature is 20-100°C, for example 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C.

[0039] In some embodiments, the hydrolysis polymerization reaction temperature is 40-90°C.

[0040] In some embodiments, the hydrolysis polymerization reaction time is 1-6h, for example 1h, 2h, 3h, 4h, 5h or 6h.

[0041] In some embodiments, the hydrolysis polymerization reaction time is 2-4h.

[0042] In some embodiments, the method for preparing the silicone sol comprises adding a silicone source precursor to an alcohol, then adding deionized water dropwise under stirring at 20-100°C, and finally adding hydrochloric acid dropwise, and continuously heating at 20-100°C for 1-6h under stirring to obtain the silicone sol.

[0043] In some embodiments, the silicone precursor is a bridged organosilane.

[0044] In some embodiments, the silicone precursor is selected from one or more of the following: methyltriethoxysilane, 1,2-bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-di(triethoxysilyl)ethene and phenyltriethoxysilane.

[0045] In some embodiments, the catalyst is hydrochloric acid, and the concentration of the hydrochloric acid is 0.01-10 wt%, for example, 0.01 wt%, 0.1 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%.

[0046] In some embodiments, the alcohol is one or a mixture of methanol, ethanol, n-propanol, and isopropanol.

[0047] In some embodiments, the mass ratio of the amount of the alcohol added to the organosilicon source precursor is (5-100): 1, for example, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, or 100:1.

[0048] In some embodiments, the mass ratio of the amount of the alcohol added to the organosilicon source precursor is (10-50): 1.

[0049] In some embodiments, the molar ratio of the organosilicon source precursor, deionized water, and hydrogen chloride in hydrochloric acid is 1:(30-120):(0.05-1), for example, 1:(30, 40, 50, 60, 70, 80, 90, 100, 110, 120):(0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1).

[0050] In some embodiments, the molar ratio of the organosilicon source precursor, deionized water, and hydrogen chloride in hydrochloric acid is 1:(50-90):(0.1-0.5).

[0051] In some embodiments, the method for preparing the organosilicon composite film comprises: coating an organosilicon film on a base film to obtain the organosilicon composite film.

[0052] In some embodiments, the coating process can be repeated 2-5 times according to the film formation condition.

[0053] In some embodiments, the coating method is any one of spraying, blade coating, or spin coating.

[0054] In some embodiments, the method further comprises drying the organosilicon composite film.

[0055] In some embodiments, the drying temperature is 20-180°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0056] In some embodiments, the drying temperature is 60-150°C.

[0057] In some embodiments, the drying time is 5 min-24 h, for example 5 min, 0.5 h, 5 h, 10 h, 15 h, 20 h or 24 h.

[0058] In some embodiments, the drying time is 10 min-1 h.

[0059] In some embodiments, the method for preparing the base film comprises:

[0060] S1, adding an organic high molecular polymer into a solvent for heating and stirring to prepare a casting solution;

[0061] S2, coating the casting solution obtained in step S1 on a casting body to obtain the base film.

[0062] In some embodiments, the organic high molecular polymer is selected from one or more of polysulfone, polyether sulfone, sulfonated polyether sulfone, polyimide, polyvinyl alcohol or polypropylene.

[0063] In some embodiments, the solvent is one or more of N-methyl pyrrolidone (NMP), dimethylformamide (DMF) or dimethylacetamide (DMAc).

[0064] In some embodiments, the mass ratio of the organic high molecular polymer and the solvent is (0.05-0.3):1; for example 0.05:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1 or 0.3:1.

[0065] In some embodiments, the mass ratio of the organic high molecular polymer and the solvent is (0.1-0.2):1.

[0066] In some embodiments, the heating temperature in step S1 is 50-150°C, for example 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C.

[0067] In some embodiments, the heating temperature in step S1 is 50-90°C.

[0068] In some embodiments, the heating time in step S1 is 1-5 h, for example 1 h, 2 h, 3 h, 4 h or 5 h.

[0069] In some embodiments, the heating time in step S1 is 2-4 h.

[0070] In some embodiments, the coating method in step S2 is any one of spraying, doctor blading or spin coating.

[0071] In some embodiments, the method for preparing the base film further comprises drying the base film.

[0072] In some embodiments, the drying temperature is 50-180°C, for example 50°C, 70°C, 90°C, 110°C, 130°C, 150°C, 170°C or 180°C.

[0073] In some embodiments, the drying time is 5 min-120 min, for example 5 min, 20 min, 40 min, 60 min, 80 min, 100 min or 120 min.

[0074] In some embodiments, the method for preparing the base film comprises:

[0075] A. adding organic polymer particles to an N-methyl pyrrolidone solution, dissolving and preparing a casting solution of a certain concentration after heating and stirring for 1-5 h;

[0076] B. coating the casting solution obtained in step A on a smooth casting body using a film coating method, drying at 50-180°C for 5 min-120 min to obtain the base film.

[0077] In some embodiments, the method for preparing the organic composite silicon film comprises the following steps:

[0078] (1) adding a bridged oxygen-containing silane as an organosilicon source precursor to an alcohol solution, then adding deionized water drop by drop under heating and stirring conditions, the heating temperature is 20-100°C, the stirring time is 1-6 h; finally, gradually adding hydrochloric acid, continuously heating and stirring at 20-100°C for 1-6 h to obtain an organosilicon sol;

[0079] (2) adding a hydrophobic additive to the organosilicon sol gel of step (1), continuously heating and stirring at 20-100°C for 0.1-4 h to prepare a blended organosilicon sol gel solution;

[0080] (3) coating the blended organosilicon sol gel solution obtained in step (2) on the base film using a film coating method, drying at 20-180°C for 5 min-24 h to obtain a preliminary organic flexible silicon film, according to the film forming situation, the process can be repeated 2-5 times, and finally an organosilicon film is obtained.

[0081] In a second aspect, the present application provides an oxidation tail gas treatment system, comprising a membrane separation unit, wherein the membrane separation unit comprises an organic composite silicon membrane; and the organic composite silicon membrane comprises a base membrane and an organic silicon membrane, and the organic silicon membrane comprises an organic silicon polymer and a hydrophobic additive.

[0082] In some embodiments, the oxidation tail gas is generated from an oxidation reaction unit for preparing phenol and acetone from cumene.

[0083] In some embodiments, the content of organic matters in the oxidation tail gas is 100-15000 g / m 3 .

[0084] In some embodiments, the membrane separation unit comprises at least one membrane separator, and the membrane separator comprises the organic composite silicon membrane.

[0085] In some embodiments, the membrane separation unit comprises a plurality of membrane separators connected in parallel.

[0086] In some embodiments, the oxidation reaction unit comprises an oxidation reaction tower.

[0087] In some embodiments, the oxidation tail gas treatment system further comprises a cooling unit.

[0088] In some embodiments, the cooling unit comprises a heat exchanger and a gas-liquid condensation separation tower connected in sequence, wherein the heat exchanger is connected to the oxidation reaction unit; and the gas-liquid condensation separation tower is connected to the membrane separation unit.

[0089] In some embodiments, the oxidation tail gas treatment system further comprises an adsorption unit connected to the membrane separation unit.

[0090] In some embodiments, the adsorption unit comprises at least one adsorption tower.

[0091] In some embodiments, the adsorption unit comprises a plurality of adsorption towers connected in parallel.

[0092] In some embodiments, the adsorption tower comprises an adsorbent.

[0093] In some embodiments, the adsorbent is selected from one or more of activated carbon, molecular sieve, silica gel, and granular white clay.

[0094] In some embodiments, the oxidation tail gas treatment system further comprises a recovery unit connected to the membrane separation unit and the adsorption unit.

[0095] In some embodiments, the recovery unit comprises a recovery tank.

[0096] In some embodiments, the hydrophobic additive is one or more of ultrafine graphene, white carbon black, or carbon nanotubes.

[0097] In some embodiments, the hydrophobic additive has a particle size of 0.3-50 nm, for example 0.3 nm, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm.

[0098] In some embodiments, the hydrophobic additive has a particle size of 0.5-20 nm.

[0099] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon polymer is 1:(10-1000), for example 1:10, 1:30, 1:50, 1:70, 1:90, 1:110, 1:130, 1:150, 1:170, 1:190, 1:200, 1:250, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, or 1:1000.

[0100] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-300).

[0101] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-200).

[0102] In some embodiments, the mass ratio of the hydrophobic additive to the organosilicon sol is 1:(50-100).

[0103] In some embodiments, the method for preparing the organosilicon film comprises mixing an organosilicon sol with a hydrophobic additive and heating to obtain the organosilicon film.

[0104] In some embodiments, the temperature of the heating is 20-100℃, for example 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, or 100℃.

[0105] In some embodiments, in step (1), the temperature of the heating is 40-90℃.

[0106] In some embodiments, the time of the heating is 0.1-4 h, for example 0.1 h, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h.

[0107] In some embodiments, the time of the heating is 0.2-1 h.

[0108] In some embodiments, the method for preparing the organosilica sol comprises mixing an organosilica source precursor, an alcohol, deionized water, and a catalyst, and performing a hydrolysis polymerization reaction.

[0109] In some embodiments, the hydrolysis polymerization reaction is performed at a temperature of 20-100°C, such as 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0110] In some embodiments, the hydrolysis polymerization reaction is performed at a temperature of 40-90°C.

[0111] In some embodiments, the hydrolysis polymerization reaction is performed for a time period of 1-6h, such as 1h, 2h, 3h, 4h, 5h, or 6h.

[0112] In some embodiments, the hydrolysis polymerization reaction is performed for a time period of 2-4h.

[0113] In some embodiments, the method for preparing the organosilica sol comprises adding an organosilica source precursor to an alcohol, then adding deionized water dropwise under stirring at a temperature of 20-100°C, and finally adding hydrochloric acid dropwise, and continuously heating at a temperature of 20-100°C for 1-6h to obtain the organosilica sol.

[0114] In some embodiments, the organosilica precursor is a bridged organosilane.

[0115] In some embodiments, the organosilica precursor is selected from one or more of methyltriethoxysilane, 1,2-bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-di(triethoxysilyl)ethene, and phenyltriethoxysilane.

[0116] In some embodiments, the catalyst is hydrochloric acid, and the concentration of the hydrochloric acid is 0.01-10wt%, such as 0.01wt%, 0.1wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, or 10wt%.

[0117] In some embodiments, the alcohol is one or more of methanol, ethanol, n-propanol, or isopropanol.

[0118] In some embodiments, the alcohol is added in an amount of 5-100:1 by mass ratio to the organosilica source precursor, such as 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, or 100:1.

[0119] In some embodiments, the amount of the alcohol added is in a mass ratio of (10-50):1 to the silicone source precursor.

[0120] In some embodiments, the molar ratio of the silicone source precursor, deionized water, and hydrogen chloride in hydrochloric acid is 1:(30-120):(0.05-1), for example, 1:(30, 40, 50, 60, 70, 80, 90, 100, 110, 120):(0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1).

[0121] In some embodiments, the molar ratio of the silicone source precursor, deionized water, and hydrogen chloride in hydrochloric acid is 1:(50-90):(0.1-0.5).

[0122] In some embodiments, the method for preparing the organic composite silicon film comprises: coating an organic silicon composition on a base film to obtain the organic composite silicon film.

[0123] In some embodiments, the coating process can be repeated 2-5 times according to the film formation situation.

[0124] In some embodiments, the coating method is any one of spraying, blade coating, or spin coating.

[0125] In some embodiments, the method further comprises drying the organic composite silicon film.

[0126] In some embodiments, the drying temperature is 20-180°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C.

[0127] In some embodiments, the drying temperature is 60-150°C.

[0128] In some embodiments, the drying time is 5 min-24 h, for example, 5 min, 0.5 h, 5 h, 10 h, 15 h, 20 h, 24 h.

[0129] In some embodiments, the drying time is 10 min-1 h.

[0130] In some embodiments, the method for preparing the base film comprises:

[0131] S1, adding an organic high molecular polymer into a solvent for heating and stirring to prepare a casting solution;

[0132] S2, coating the casting solution obtained in step S1 on a casting body to obtain the base film.

[0133] In some embodiments, the organic high molecular polymer is selected from one or more of polysulfone, polyether sulfone, sulfonated polyether sulfone, polyimide, polyvinyl alcohol, or polypropylene.

[0134] In some embodiments, the solvent is one or more of N-methyl pyrrolidone (NMP), dimethylformamide (DMF), or dimethylacetamide (DMAc).

[0135] In some embodiments, the mass ratio of the organic high molecular polymer and the solvent is (0.05-0.3):1; for example, 0.05:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, or 0.3:1.

[0136] In some embodiments, the mass ratio of the organic high molecular polymer and the solvent is (0.1-0.2):1.

[0137] In some embodiments, the temperature of heating in step S1 is 50-150°C, for example, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C.

[0138] In some embodiments, the temperature of heating in step S1 is 50-90°C.

[0139] In some embodiments, the time of heating in step S1 is 1-5h, for example, 1h, 2h, 3h, 4h, or 5h.

[0140] In some embodiments, the time of heating in step S1 is 2-4h.

[0141] In some embodiments, the method of coating in step S2 is any one of spraying, doctor blading, or spin coating.

[0142] In some embodiments, the method of preparing the base film further comprises drying the base film.

[0143] In some embodiments, the temperature of drying is 50-180°C, for example, 50°C, 70°C, 90°C, 110°C, 130°C, 150°C, 170°C, or 180°C.

[0144] In some embodiments, the time of drying is 5min-120min, for example, 5min, 20min, 40min, 60min, 80min, 100min, or 120min.

[0145] In some embodiments, the method of preparing the base film comprises:

[0146] A, the organic polymer particles are added to an N-methyl pyrrolidone solution, and after heating and stirring for 1-5 h, the organic polymer particles are dissolved to form a casting solution with a certain concentration;

[0147] B, the casting solution obtained in step A is coated on a smooth casting body by a film coating method, and dried at 50-180 DEG C for 5 min-120 min to obtain the base film.

[0148] In some embodiments, the preparation method of the organic composite silicon film comprises the following steps:

[0149] (1) the bridged oxygen-containing silane is used as an organic silicon source precursor and added to an alcohol solution, then deionized water is added dropwise under heating and stirring, the heating temperature is 20-100 DEG C, the stirring time is 1-6 h, and finally hydrochloric acid is gradually added, and after continuous heating and stirring at 20-100 DEG C for 1-6 h, an organic silicon sol is obtained;

[0150] (2) the hydrophobic additive is added to the organic silicon sol gel of step (1), and after continuous heating and stirring at 20-100 DEG C for 0.1-4 h, a blended organic silicon sol gel liquid is prepared;

[0151] (3) the blended organic silicon sol gel liquid obtained in step (2) is coated on the base film by a film coating method, and after drying at 20-180 DEG C for 5 min-24 h, a preliminary organic flexible silicon film is obtained, and according to the film forming condition, the process can be repeated 2-5 times, and finally the organic silicon film is obtained.

[0152] The organic composite silicon film in the application contains a hydrophobic additive, which can greatly improve and alleviate the swelling of the film caused by water vapor and prolong the service life of the film. The membrane separation unit containing the organic composite silicon film is used to separate the oxidation tail gas, which is low in cost, green and efficient, low in carbon emission, energy saving and consumption reducing, and can separate most of the organic gas for recycling, thereby generating greater economic benefits. Compared with the catalytic oxidation and catalytic combustion method, the method also greatly reduces the CO2 emission. The method has the advantages of simple process flow, low investment, green environmental protection, low carbon emission, stable operation and good economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0153] Figure 1 It is an oxidation tail gas treatment system process schematic diagram in the embodiment of the application;

[0154] 1, oxidation reaction tower, 2, heat exchanger, 3, gas-liquid condensation separation tower, 4, first membrane separator, 5, second membrane separator, 6, first adsorption tower, 7, second adsorption tower, 8, recovery tank, 9, air compressor. DETAILED DESCRIPTION

[0155] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and drawings. The specific embodiments described herein are only used to explain the present application and should not be used to constitute any limitation on the present application. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0156] In the oxidation process production device, organic matter is used as raw material, and air is used to react with the organic matter in the oxidation stage to produce intermediate products while generating tail gas, which is referred to as oxidation tail gas.

[0157] Preparation Example 1

[0158] (1) 10 g of polyether sulfone was weighed into 59 g of N-methyl pyrrolidone solution, and stirred at 75°C water bath heating for 4 h until the particles were completely dissolved, to prepare a 14.5% (wt) casting solution.

[0159] (2) The cleaned copper foil sheet (10 cm x 10 cm) was fixed on the coating machine, and the film thickness was adjusted to 50-100 m. 5 mL of the casting solution of step (1) was weighed and uniformly coated on one end of the copper foil sheet, and the machine was started to scrape the film. The film was dried at 100°C for 10 min to prepare a flexible organic film.

[0160] (3) 14.8 g of methyl triethoxysilane was weighed, and then 300 g of isopropyl alcohol was added. 120 g of deionized water was added dropwise under 60°C water bath heating, and then 4 g of 10 wt% hydrochloric acid was added dropwise. After stirring for 4 hours, 0.15 g of 10 nm graphene (the mass ratio of graphene to methyl triethoxysilane was 1:98) was added, and the stirring was continued at 60°C for 1 hour. A blended organosilica sol gel solution was prepared.

[0161] (4) 50 g of the blended organosilica sol gel solution prepared in step (3) was sprayed on the flexible organic film prepared in step (2) by electrostatic spraying method, and dried at 100°C for 30 min to prepare a composite silicon film.

[0162] Preparation Example 2

[0163] Different from Example 1, in step (3), the graphene was replaced by carbon nanotubes.

[0164] Preparation Example 3

[0165] Different from Example 1, in step (3), the graphene was replaced by white carbon black.

[0166] Preparation Example 4

[0167] (1) 10 g of polyether sulfone was weighed into 59 g of N-methylpyrrolidone solution, and stirred at 75°C in a water bath for 4 h until the particles were completely dissolved to form a 14.5% (wt) casting solution.

[0168] (2) The cleaned copper foil sheet (10 cm x 10 cm) was fixed on a coating machine, and the film thickness was adjusted to 50-100 m. 5 mL of the casting solution prepared in step (1) was evenly coated on one end of the copper foil sheet, and the machine was started to scrape the film. The film was dried at 100°C for 10 min to prepare a flexible organic film.

[0169] (3) 14.8 g of methyltriethoxysilane was weighed, and then 300 g of isopropyl alcohol was added. 120 g of deionized water was added dropwise under 60°C water bath heating, and then 4 g of 10 wt% hydrochloric acid was added dropwise. The mixture was stirred for 4 h to prepare a silicone sol gel solution.

[0170] (4) 50 g of the silicone sol gel solution prepared in step (3) was weighed and sprayed on the flexible organic film prepared in step (2) by electrostatic spraying. The mixture was dried at 100°C for 30 min to prepare a silicon film.

[0171] Example 1

[0172] The organic composite silicon film prepared in Preparation Example 1 was applied to a membrane separation unit.

[0173] According to the flowchart shown in Figure 1 , isopropylbenzene and air were preheated, isopropylbenzene was introduced from the upper part of the oxidation reaction tower 1, and air was introduced from the bottom of the oxidation reaction tower 1. The oxidation reaction occurred at 0.3 MPa and 100°C to generate hydrogen peroxide isopropylbenzene (CHP). CHP continuously flowed out from the lower part of the oxidation reaction tower 1 into an acidolysis unit. The organic oxidation tail gas (the organic content in the tail gas was 3200-12000 mg / m 3 , the main component of the organic matter was isopropylbenzene, and it also contained trace amounts of alcohol, ketone, acid, and other organic matters and harmful substances such as non-aromatic hydrocarbons) was preliminarily cooled to 10-30°C by a heat exchanger 2 and then introduced into a gas-liquid condensation separation tower 3 for deep cooling and recovery. The liquefied organic matter flowed out from the bottom of the gas-liquid condensation separation tower 3, and most of the liquefied organic matter was isopropylbenzene. The liquefied organic matter could be recycled as a reaction raw material into the oxidation reaction tower 1.

[0174] The tail gas flowing out from the top of the gas-liquid condensation separation tower 3 was introduced into a first membrane separator 4 at a pressure of 0.3 MPa and a temperature of 10-30°C, and a second membrane separator 5 was used as a backup. The organic matter separated by the first membrane separator 4 was introduced into a recovery tank 8 for recovery.

[0175] The oxidation tail gas separated by the first membrane separator 4 had an organic matter concentration as shown in Table 1, and was introduced into a first adsorption tower 6 for adsorption, and a second adsorption tower 7 was used as a backup.

[0176] The oxidation tail gas after adsorption and separation by the first adsorption tower 6 has an organic matter concentration of less than 50 ppm, which meets the emission standards and can be discharged directly or partially recycled and mixed with oxygen-enriched air, compressed to 0.3 MPa by the air compressor 9, and then mixed with fresh air as oxidation raw gas.

[0177] After membrane separation, the oxidized tail gas is saturated with the adsorbent (molecular sieve) in the first adsorption tower 6 of the adsorption unit. It can then be regenerated using hot air or steam. Organic matter adsorbed in the adsorbent is entrained by the regeneration gas and condensed to recover the liquefied organic matter. The regenerated adsorbent can continue to be used.

[0178] Example 2

[0179] The organic composite silicon membrane prepared in Preparation Example 2 was applied to a membrane separation unit.

[0180] according to Figure 1 In the process shown, cumene and air are preheated, cumene enters from the top of oxidation reaction tower 1, and air enters from the bottom of oxidation reaction tower 1. Oxidation reaction occurs under the conditions of 0.3 MPa and 100°C to generate cumene hydroperoxide (CHP). CHP flows continuously out of the bottom of oxidation reaction tower 1 and enters the acid hydrolysis unit. 3 The main component of the organic matter is isopropylbenzene, and it also contains trace amounts of organic matter such as alcohols, ketones, acids and harmful substances such as non-aromatic hydrocarbons) and is initially cooled to 10-30°C by the heat exchanger 2 and then enters the gas-liquid condensation separation tower 3 for deep cooling and recovery. The liquefied organic matter flows out from the bottom of the gas-liquid condensation separation tower 3. Most of the liquefied organic matter is isopropylbenzene. The liquefied organic matter can enter the oxidation reaction tower 1 and be recovered and used as a reaction raw material.

[0181] The oxidation tail gas flowing out of the top of the gas-liquid condensation separation tower 3, with a pressure of 0.3 MPa and a temperature of 10-30°C, enters the first membrane separator 4. The second membrane separator 5 serves as a backup. The organic matter separated by the first membrane separator 4 enters the recovery tank 8 for recovery.

[0182] The oxidation tail gas separated by the first membrane separator 4 has an organic matter concentration as shown in Table 1 and enters the first adsorption tower 6 for adsorption, while the second adsorption tower 7 is kept in reserve.

[0183] The organic matter concentration of the oxidized tail gas after adsorption and separation in the first adsorption tower 6 is less than 50 mg / m 3 , and meets the emission standards, it can be discharged directly, or partially recycled, mixed with oxygen-enriched air, compressed to 0.3MPa by air compressor 9, and then mixed with fresh air as oxidation raw gas.

[0184] The oxidized tail gas after membrane separation is saturated by adsorption of the adsorbent (molecular sieve) in the first adsorption tower 6 of the adsorption unit, and can be regenerated by hot air or water vapor. The adsorbed organic matter in the adsorbent is entrained by the regeneration gas, and after condensation, the liquefied organic matter can be recovered. The adsorbent can continue to be used after regeneration.

[0185] Example 3

[0186] The organic composite silicon film in Preparation Example 3 is applied to the membrane separation unit.

[0187] According to the flow shown in Figure 1 , isopropylbenzene and air are preheated, isopropylbenzene enters from the upper part of the oxidation reaction tower 1, and air enters from the bottom of the oxidation reaction tower 1. Oxidation reaction occurs at 0.3 MPa and 100°C to generate cumene hydroperoxide (CHP). CHP continuously flows out from the lower part of the oxidation reaction tower 1 into the acidolysis unit. The oxidized tail gas containing organic matter (the content of organic matter in the tail gas is 3200-12000 mg / m 3 , the main component of which is isopropylbenzene, and also contains trace amounts of organic matter such as alcohol, ketone, acid, and harmful substances such as non-aromatic hydrocarbons) is preliminarily cooled to 10-30°C by a heat exchanger 2 and then enters a gas-liquid condensation separation tower 3 for deep cooling and recovery. The liquefied organic matter flows out from the bottom of the gas-liquid condensation separation tower 3, and most of the liquefied organic matter is isopropylbenzene. The liquefied organic matter can be recycled and used as a reaction raw material into the oxidation reaction tower 1.

[0188] The oxidized tail gas flowing out from the top of the gas-liquid condensation separation tower 3 at a pressure of 0.3 MPa and a temperature of 10-30°C enters a first membrane separator 4, and a second membrane separator 5 is used as a backup. The organic matter separated by the first membrane separator 4 enters a recovery tank 8 for recovery.

[0189] The oxidized tail gas separated by the first membrane separator 4 has an organic matter concentration as shown in Table 1, and enters a first adsorption tower 6 for adsorption, and a second adsorption tower 7 is used as a backup.

[0190] The oxidized tail gas after adsorption separation by the first adsorption tower 6 has an organic matter concentration of less than 50 mg / m 3 , which meets the emission standard and can be directly discharged or partially recycled and mixed with oxygen-enriched air, compressed to 0.3 MPa by an air compressor 9, and then mixed with fresh air as oxidation raw gas.

[0191] The oxidized tail gas after membrane separation is saturated by adsorption of the adsorbent (molecular sieve) in the first adsorption tower 6 of the adsorption unit, and can be regenerated by hot air or water vapor. The adsorbed organic matter in the adsorbent is entrained by the regeneration gas, and after condensation, the liquefied organic matter can be recovered. The adsorbent can continue to be used after regeneration.

[0192] Comparative Example 1

[0193] The silicon membrane prepared in Preparation Example 4 was applied to a membrane separation unit.

[0194] according to Figure 1 In the process shown, cumene and air are preheated, cumene enters from the top of oxidation reaction tower 1, and air enters from the bottom of oxidation reaction tower 1. Oxidation reaction occurs under the conditions of 0.3 MPa and 100°C to generate cumene hydroperoxide (CHP). CHP flows continuously out of the bottom of oxidation reaction tower 1 and enters the acid hydrolysis unit. 3 The main component of the organic matter is isopropylbenzene, and it also contains trace amounts of organic matter such as alcohols, ketones, acids and harmful substances such as non-aromatic hydrocarbons) and is initially cooled to 10-30°C by the heat exchanger 2 and then enters the gas-liquid condensation separation tower 3 for deep cooling and recovery. The liquefied organic matter flows out from the bottom of the gas-liquid condensation separation tower 3. Most of the liquefied organic matter is isopropylbenzene. The liquefied organic matter can enter the oxidation reaction tower 1 and be recovered and used as a reaction raw material.

[0195] The oxidation tail gas flowing out of the top of the gas-liquid condensation separation tower 3, with a pressure of 0.3 MPa and a temperature of 10-30°C, enters the first membrane separator 4. The second membrane separator 5 serves as a backup. The organic matter separated by the first membrane separator 4 enters the recovery tank 8 for recovery.

[0196] The oxidation tail gas separated by the first membrane separator 4 has an organic matter concentration as shown in Table 1 and enters the first adsorption tower 6 for adsorption, while the second adsorption tower 7 is kept in reserve.

[0197] The organic matter concentration of the oxidized tail gas after adsorption and separation in the first adsorption tower 6 is less than 50 mg / m 3 , and meets the emission standards, it can be discharged directly, or partially recycled, mixed with oxygen-enriched air, compressed to 0.3MPa by air compressor 9, and then mixed with fresh air as oxidation raw gas.

[0198] After membrane separation, the oxidized tail gas is saturated with the molecular sieve adsorbent in the first adsorption tower 6 of the adsorption unit. It can then be regenerated using hot air or steam. Organic matter adsorbed in the adsorbent is entrained by the regeneration gas and condensed to recover the liquefied organic matter. The regenerated adsorbent can continue to be used.

[0199] The membrane inlet concentrations in the examples of the present invention and the comparative examples are substantially the same, the membrane permeate side refers to the membrane front outlet, and the membrane retentate side refers to the membrane side outlet.

[0200] Table 1

[0201]

[0202] As can be seen from Table 1, compared with the silicon membrane used in Comparative Example 1, the membrane separation unit containing the organic composite silicon membrane used in the embodiment of the present invention can more efficiently separate isopropylbenzene from the oxidation tail gas, and the organic composite silicon membrane in Examples 1-3 of the present invention has a longer lifespan and can still achieve a high separation ratio for isopropylbenzene and other organic matter after 48 hours.

[0203] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method of treating an oxidation tail gas comprising: membrane separation is performed on the oxidation tail gas, The membrane separation is performed by using an organic composite silicon membrane; the organic composite silicon membrane comprises a base film and an organic silicon membrane, and the organic silicon membrane comprises an organic silicon polymer and a hydrophobic additive; Preferably, the oxidation tail gas is a tail gas from the reaction of cumene oxidation to produce phenol and / or acetone; preferably, the content of organic matter in the oxidation tail gas is 100-15000 g / m 3 .

2. The method of claim 1, wherein the oxidizing tail gas is treated by a method comprising: The oxidation tail gas treatment method further comprises: cooling the oxidation tail gas before the membrane separation; preferably, the cooling temperature is 0-60℃, preferably 10-30℃; The oxidation tail gas treatment method further comprises: performing adsorption on the oxidation tail gas after the membrane separation; Preferably, the oxidation tail gas treatment method comprises: (1) performing oxidation on cumene to obtain oxidation tail gas, and performing gas-liquid separation on the obtained oxidation tail gas after cooling to obtain liquefied organic matter and tail gas; (2) performing the membrane separation on the tail gas obtained in step (1) to obtain oxidation tail gas after the membrane separation and tail gas containing organic matter; (3) performing adsorption on the oxidation tail gas after the membrane separation; (4) performing organic matter recovery on the tail gas containing organic matter in step (2) and the tail gas after the adsorption in step (3).

3. The oxidation off-gas treatment method according to claim 1 or 2, characterized by, The hydrophobic additive is one or more of ultra-fine graphene, white carbon black and carbon nanotube; and / or The particle size of the hydrophobic additive is 0.3-50nm, preferably 0.5-20nm; and / or The mass ratio of the hydrophobic additive to the organic silicon polymer is 1:(10-1000), preferably 1:(50-300).

4. The oxidation tail gas treatment method according to any one of claims 1 to 3, characterized by, The preparation method of the organic silicon membrane comprises: mixing an organic silicon sol and a hydrophobic additive and performing heating to obtain the organic silicon membrane; Preferably, the heating temperature is 20-100℃, preferably 40-90℃; and the heating time is 0.1-4h, preferably 0.2-1h. Preferably, the preparation method of the organic silicon sol comprises: mixing an organic silicon source precursor, alcohol, deionized water and a catalyst and performing hydrolysis polymerization reaction; Preferably, the hydrolysis polymerization reaction temperature is 20-100℃, preferably 40-90℃; and the hydrolysis polymerization reaction time is 1-6h, preferably 2-4h. Preferably, the organic silicon precursor is a bridged organosilane; More preferably, the organic silicon precursor is selected from one or more of a mixture of methyl triethoxysilane, 1,2-bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-di(triethoxysilyl)ethylene and phenyl triethoxysilane; and / or The catalyst is hydrochloric acid, and the concentration of the hydrochloric acid is 0.01-10wt%; and / or The alcohol is one or more of a mixture of methanol, ethanol, n-propanol or isopropanol; Preferably, the mass ratio of the alcohol to the organic silicon source precursor is (5-100):1, preferably (10-50):1; Preferably, the molar ratio of hydrogen chloride in the organic silicon source precursor, deionized water and hydrochloric acid is 1:(30-120):(0.05-1), preferably 1:(50-90):(0.1-0.5).

5. The oxidation tail gas treatment method according to any one of claims 1 to 4, characterized by, The preparation method of the organic composite silicon membrane comprises: coating an organic silicon membrane on a base film to obtain the organic composite silicon membrane. Preferably, the coating method is any one of spraying, doctor blading or spin coating; Preferably, the preparation method further comprises drying the organic composite silicon film, preferably, the drying temperature is 20-180℃, preferably 60-150℃; the drying time is 5min-24h, preferably 10min-1h; Preferably, the preparation method of the base film comprises: S1, adding an organic high polymer into a solvent for heating and stirring to prepare a casting solution; S2, coating the casting solution obtained in step S1 on a casting body to obtain the base film; Preferably, the organic high polymer is selected from one or more of polysulfone, polyether sulfone, sulfonated polyether sulfone, polyimide, polyvinyl alcohol or polypropylene; The solvent is one or more of N-methyl pyrrolidone, dimethylformamide or dimethylacetamide; Preferably, the mass ratio of the organic high polymer and the solvent is (0.05-0.3):1, preferably (0.1-0.2):1; Preferably, in step S1, the heating temperature is 50-150℃, preferably 50-90℃; the heating time is 1-5h, preferably 2-4h.

6. An oxidation off-gas treatment system comprising a membrane separation unit, the membrane separation unit comprising an organic composite silicon membrane; the organic composite silicon membrane comprising a base membrane and an organosilicon membrane, the organosilicon membrane comprising an organosilicon polymer and a hydrophobic additive; preferably, the oxidation off-gas is an off-gas produced from a reaction of cumene in an oxidation reaction unit to produce phenol and / or acetone; preferably, the oxidation off-gas has an organic content of 100-15000 g / m3. 3 .

7. The oxidation off-gas treatment system according to claim 6, characterized by The membrane separation unit comprises at least one membrane separator, which contains an organic composite silicon film inside, preferably, the membrane separation unit comprises a plurality of parallel membrane separators; and / or, the oxidation reaction unit comprises an oxidation reaction tower; Preferably, the oxidation tail gas treatment system further comprises a cooling unit, preferably, the cooling unit comprises a heat exchanger and a gas-liquid condensation separation tower connected in sequence, the heat exchanger is connected with the oxidation reaction unit; the gas-liquid condensation separation tower is connected with the membrane separation unit; and / or, The oxidation tail gas treatment system further comprises an adsorption unit connected with the membrane separation unit, preferably, the adsorption unit comprises at least one adsorption tower, preferably, the adsorption tower contains an adsorbent inside, preferably, the adsorbent is selected from one or more of activated carbon, molecular sieve, silica gel or granular white clay; and / or, The oxidation tail gas treatment system further comprises a recovery unit connected with the membrane separation unit and the adsorption unit, preferably, the recovery unit comprises a recovery tank.

8. The oxidation off-gas treatment system according to claim 6 or 7, characterized by, The hydrophobic additive is one or more of ultra-fine graphene, white carbon black or carbon nanotube; and / or The particle size of the hydrophobic additive is 0.3-50nm, preferably 0.5-20nm; and / or The mass ratio of the hydrophobic additive to the organic silicon polymer is 1:(10-1000), preferably 1:(50-300).

9. The oxidation tail gas treatment system according to any one of claims 6-8, characterized in that, The preparation method of the organic silicon film comprises mixing an organic silicon sol and a hydrophobic additive and heating to obtain the organic silicon film; Preferably, the heating temperature is 20-100℃, preferably 40-90℃; the heating time is 0.1-4h, preferably 0.2-1h; Preferably, the preparation method of the organic silicon sol comprises mixing an organic silicon source precursor, alcohol, deionized water and a catalyst for hydrolysis polymerization reaction; Preferably, the temperature of the hydrolysis polymerization reaction is 20-100℃, preferably 40-90℃; the time of the hydrolysis polymerization reaction is 1-6h, preferably 2-4h; Preferably, the organic silicon precursor is a bridged type oxygen-containing silane; More preferably, the organic silicon precursor is selected from one or a mixture of several of methyltriethoxysilane, 1,2-bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-di(triethoxysilyl)ethene and phenyltriethoxysilane; and / or The catalyst is hydrochloric acid, and the concentration of the hydrochloric acid is 0.01-10wt%; and / or The alcohol is one or a mixture of several of methanol, ethanol, n-propanol or isopropanol; Preferably, the mass ratio of the amount of the alcohol added to the organic silicon source precursor is (5-100):1, preferably (10-50):1; Preferably, the molar ratio of the organic silicon source precursor, deionized water and hydrogen chloride in the hydrochloric acid is 1:(30-120):(0.05-1), preferably 1:(50-90):(0.1-0.5).

10. The oxidation tail gas treatment system according to any one of claims 6-9, characterized in that, The preparation method of the organic composite silicon film comprises: coating an organic silicon composition on a base film to obtain the organic composite silicon film; Preferably, the coating method is any one of spraying, doctor blading or spin coating; Preferably, the preparation method further comprises drying the organic composite silicon film, and preferably, the temperature of the drying is 20-180℃, preferably 60-150℃; the time of the drying is 5min-24h, preferably 10min-1h; Preferably, the preparation method of the base film comprises: S1, adding an organic high molecular polymer into a solvent for heating and stirring to prepare a casting solution; S2, coating the casting solution obtained in step S1 on a casting body to obtain the base film; Preferably, the organic high molecular polymer is selected from one or more of polysulfone, polyethersulfone, sulfonated polyethersulfone, polyimide, polyvinyl alcohol or polypropylene; The solvent is one or more of N-methylpyrrolidone, dimethylformamide or dimethylacetamide; Preferably, the mass ratio of the organic high molecular polymer and the solvent is (0.05-0.3):1, preferably (0.1-0.2):1; Preferably, in step S1, the temperature of the heating is 50-150℃, preferably 50-90℃; the time of the heating is 1-5h, preferably 2-4h.

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