Refinery alkali residue resourceful treatment process and treatment system

Abstract

The invention relates to a refinery alkali residue resourceful treatment process and system, and the process comprises the following steps: (1) firstly, enabling alkali residues to enter a desulfurization unit, and carrying out desulfurization treatment on the alkali residues by using copper oxide as a precipitator; (2) the desulfurized alkali residues enter a neutralization unit and are neutralized by using CO2 gas as a neutralizer, (3) the neutralized alkali residues enter a refining unit and are subjected to catalytic ozonation by using ozone and hydrogen peroxide as oxidants, and (4) the refined alkali residues enter an alkali recovery unit and are subjected to a causticization reaction. And (5) waste gas generated by the desulfurization unit, the neutralization unit, the refining unit and the alkali recovery unit enters a tail gas treatment unit, is absorbed by an absorbent and then is discharged to the atmosphere, and saturated absorption liquid is fed into the desulfurization unit and is circularly treated together with alkali residues. The alkaline residue resourceful treatment process is wide in applicability, high in organic matter degradation rate, high in resourceful degree and capable of achieving zero discharge of waste liquid.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental wastewater treatment, and specifically relates to a refinery alkali slag resource treatment process and a treatment system. Background Art

[0002] Alkali residue is the waste alkali liquid produced when petroleum is refined. Its COD, sulfide and phenol emissions account for 40-50% of the total pollutant emissions of the refinery. The composition of alkali residue is very complex. Various sulfides, phenols and other toxic and harmful compounds have the characteristics of high alkalinity, high toxicity, heavy color and foul odor. If it is discharged, it will inevitably cause serious environmental pollution. The treatment of alkali residue from petroleum refined oil products has always been a recognized problem in the environmental protection community. The research on the resource and volume reduction comprehensive utilization technology of alkali residue is of great significance to environmental protection. If the alkali residue can be recycled and utilized as a resource, it can not only reduce the burden of refinery wastewater treatment, but also improve the economic benefits of the enterprise.

[0003] At present, refineries mainly use treatment methods with neutralization as the core to treat alkali residue wastewater, mainly including sulfuric acid neutralization method and carbon dioxide method. Most refineries use sulfuric acid neutralization method to treat catalytic gasoline alkali residue and atmospheric diesel alkali residue, but this method will produce a large amount of acidic wastewater that is difficult to treat. Relatively speaking, although the CO2 neutralization method can avoid the problem of acidic wastewater, it will generate sodium carbonate, causing emulsification of the system, which in turn hinders the complete separation of crude phenol and cyclohexane acid. Therefore, how to effectively treat alkali residue wastewater is still a major challenge facing refineries.

[0004] CN201910347703.4 discloses a combined process method for the graded treatment of oil refining alkali residue wastewater, which treats the alkali residue wastewater by acid neutralization, coagulation and sedimentation, advanced oxidation and A / O biochemical treatment; the technical equipment occupies a small area, is simple and practical, and has a high degree of automation, but it cannot effectively treat sulfides, the degradation of COD is not thorough enough, which will increase the burden on subsequent wastewater treatment processes, and the effluent has a high salt content.

[0005] CN201911418212.0 discloses a method and device for treating oil refining alkali residue, which treats waste gas through two-stage acidification, catalytic oxidation desulfurization, sulfur production and SO2 adsorption units, avoiding the poisoning effect of sulfide on the catalyst, and can maintain long-term stable operation, and recover high-quality sulfur resources, with better economic efficiency. However, the disadvantage of this method is that the effluent has a high salt content and a low organic matter degradation rate, resulting in the effluent water quality failing to fully meet the standards, and the process applicability is limited.

[0006] CN201410731141.0 discloses a method for treating oil refining alkali residue waste liquid, by absorbing SO2 with an oil agent to be treated with ammonia, and acidifying the alkali residue waste liquid. The method effectively removes sulfide and COD in the alkali residue waste liquid, and is particularly suitable for alkali residue waste liquid with a high content of organic sulfide, achieving efficient and economical treatment. However, the disadvantages of this method are that the effluent water quality is not ideal, the degree of resource utilization is low, the effluent salt content is high, and the process applicability is limited, and there are differences in the treatment effects of different types of alkali residue waste liquid.

[0007] CN201510800827.5 discloses a method for deep treatment of oil refining alkali residue, which uses hydrochloric acid for acidification treatment, then performs oil-water separation, and finally performs electrochemical treatment to make the wastewater meet the discharge requirements. The method efficiently removes COD and sulfide in the alkali residue waste liquid, and realizes the deep treatment of the alkali residue waste liquid. However, the shortcomings of this method are limited process applicability, low resource utilization, and high salt content of the effluent.

[0008] In summary, the existing technology still has many shortcomings, including limited process applicability, no effective degradation of complex organic matter, unsatisfactory removal of sulfur-containing pollutants, no suitable desalination process, effluent still requires subsequent treatment and the degree of resource utilization is low. Summary of the invention

[0009] The first object of the present invention is to provide a refinery alkali slag resource treatment process, comprising the following steps:

[0010] (1) First, the alkali residue is fed into a desulfurization unit, and copper oxide is used as a precipitant in a desulfurization reactor to desulfurize the alkali residue. After the desulfurization product is centrifuged, the clarified liquid enters a neutralization unit, and the precipitate is sent to a copper oxide recovery unit to recover copper oxide;

[0011] (2) In the neutralization unit, CO2 gas is used as a neutralizing agent to neutralize the desulfurized alkali residue in a carbonization tower. After the neutralization product is separated by sedimentation, the oil phase is sent to the phenol recovery process to recover the crude phenol, and the water phase enters the refining unit;

[0012] (3) In the refining unit, ozone and hydrogen peroxide are used as oxidants to perform ozone catalytic oxidation on the neutralized alkali residue in an oxidation tower, and the tail gas generated during the oxidation process is sent to a tail gas recovery unit. After the oxidation product is separated by sedimentation, the oil phase is sent to a phenol recovery process to recover crude phenol, and the water phase enters an alkali recovery unit;

[0013] (4) In the alkali recovery unit, the refined alkali residue is causticized using calcium oxide. After the causticization reaction product is separated by squeezing, the solid phase is sent to the recovery unit to recover sodium hydroxide and calcium carbonate, and the liquid phase is sent to the tail gas treatment unit as an absorption liquid;

[0014] (5) The waste gas generated by the desulfurization unit, neutralization unit, refining unit and alkali recovery unit enters the tail gas treatment unit, is absorbed by the absorbent and then discharged into the atmosphere, and the saturated absorption liquid is sent to the desulfurization unit and recycled together with the alkali slag.

[0015] The desulfurization unit uses copper oxide as a precipitant, which can react with inorganic sulfur and organic sulfur in the alkali slag. After a period of reaction, a butterfly centrifuge is used for separation. The clarified liquid enters the desulfurization alkali slag can, and the precipitated turbid phase enters the desulfurization slag recovery can. After concentration, the sulfur and copper oxide are recovered.

[0016] 1) The main chemical reactions are as follows:

[0017] Na2S+CuO+H2O→2NaOH+CuS↓

[0018] 2NaSR+CuO+H2O→2NaOH+CuS↓+R2S

[0019] The precipitate generated by the reaction is mainly composed of CuS, unreacted CuO and adsorbed organic matter, and "R" in the reaction formula represents an alkyl group.

[0020] 2) The precipitate can be burned to obtain CuO, which can be recycled.

[0021] CuS+O2→CuO+SO2↑

[0022] The burning exhaust gas can be absorbed by alkaline solution and then recycled.

[0023] The alkaline solution after desulfurization is then sent to the neutralization unit, and the subsequent process operations no longer need to consider the impact of the presence of sulfur, which can improve the quality of by-products recovered in subsequent units, reduce environmental pollution, and reduce corrosion to equipment.

[0024] The neutralization unit uses CO2 as a neutralizer. Most of the phenols and cyclohexane acids contained in the raw materials are concentrated in the alkali residue in the form of sodium salts during the alkali washing process. They are decomposed during the CO2 neutralization treatment, and NaOH is also neutralized into salts. Crude phenol and a small amount of organic matter are separated and recycled.

[0025] 1) The main chemical reactions are as follows:

[0026] 2NaOH+CO2→Na2CO3+H2O

[0027] Na2S+CO2+H2O→Na2CO3+H2S

[0028] 2NaSR+CO2+H2O→Na2CO3+2RSH

[0029] 2RC6H4ONa+CO2+H2O→Na2CO3+2RC6H4OH

[0030] 2RC6H4SNa+CO2+H2O→Na2CO3+2RC6H4SH

[0031] 2) Other chemical reactions are as follows:

[0032] Na2CO3+CO2+H2O→2NaHCO3

[0033] The alkali residue treated with CO2 can be separated into layers if the phenol content reaches a certain value. The upper oil phase is mainly crude phenol (RC6H4OH, RC6H4SH), and the lower water phase mainly contains sodium carbonate and sodium bicarbonate.

[0034] The refining unit adopts the super oxidation method to further refine the carbonized alkali slag and further reduce the content of organic matter and sulfide in the alkali slag.

[0035] Reaction process: In this unit, hydrogen peroxide is used as an oxidation enhancer. Theoretically, the combined use of hydrogen peroxide and ozone belongs to base-catalyzed ozone oxidation. The characteristic of this method is that hydroxyl radicals are produced through the catalytic effect between hydrogen peroxide and ozone. Hydroxyl radicals are considered to be the most oxidizing substances in advanced oxidation and can degrade organic matter in an unselective manner.

[0036] Caustic recovery unit: Sodium hydroxide is recovered from alkali residue using calcium oxide as recovery agent to achieve the purpose of salt-free discharge. Calcium oxide reacts with water to form calcium hydroxide, which then reacts with sodium carbonate and sodium bicarbonate in the refined water phase to form sodium hydroxide and calcium carbonate. Sodium hydroxide is recovered and reused, while calcium carbonate is insoluble in water and is easily separated and sold as a by-product.

[0037] Reaction process:

[0038] CaO+H2O→Ca(OH)2

[0039] NaHCO3+Ca(OH)2→NaOH+CaCO3↓+H2O

[0040] 2NaHCO3+Ca(OH)2→Na2CO3+CaCO3↓+2H2O

[0041] Na2CO3+Ca(OH)2→CaCO3↓+2NaOH

[0042] Tail gas treatment unit: Collect all the reaction tail gas, vent gas and gas overflowed from the pressure balance pipeline connected to the atmosphere, and discharge them into the atmosphere after being treated with absorption liquid. The tail gas is free of pollutants. Environmental pollution is avoided. The absorption liquid is prepared from the recycled washing liquid of the causticizing unit of this device and the alkali slag after carbonization treatment. The main components are sodium carbonate, sodium bicarbonate and sodium hydroxide. The tail gas and other gases mainly contain a small amount of sulfur-containing gas, carbon dioxide and trace ozone, which can be absorbed or destroyed by the absorption liquid. The absorption liquid is returned to the desulfurization unit for treatment.

[0043] CO2+NaOH→NaHCO3

[0044] CO2+2NaOH→Na2CO3+H2O

[0045] H2S+NaOH→NaHS+H2O

[0046] H2S+2NaOH→Na2S+2H2O

[0047] H2S+NaHCO3→NaHS+H2O+CO2↑

[0048] NaHS+NaOH→Na2S+H2O

[0049] SO2+NaOH→NaHSO3

[0050] 2SO2+NaOH→Na2SO3+H2O.

[0051] Through the above process, the COD removal rate of the refinery alkali residue waste liquid can reach more than 94%, the volatile phenol removal rate can reach more than 97%, and the sulfide removal rate can reach more than 98%. The concentration of the recovered sodium hydroxide solution can reach more than 16%, and its salt content is less than 0.98%. The tail gas has no pollutants such as VOC, sulfide, and ozone. The alkali residue waste liquid after final treatment is recycled in the form of sodium hydroxide solution, without waste liquid discharge, and the solid substances such as copper oxide and calcium carbonate generated during the process reaction can be recycled.

[0052] The materials recovered after the alkali residue resource treatment include: copper sulfide, crude phenol, calcium carbonate and sodium hydroxide. The recovery and treatment of these materials are prior art and are not described in this patent.

[0053] The carbonization tower can be a packed absorption tower or a floating valve tower. It is required to have good mass transfer and absorption effect, not easy to be blocked, and easy to clean. The specifications of the equipment are determined by the required processing capacity. The CO2 gas used for neutralization can be the carbon dioxide gas discharged from boiler flue gas or refinery hydrogen production equipment.

[0054] The oxidation tower can be a packed tower, and in addition to the packing, the tower is also filled with a catalyst. The catalyst is a prior art, and the existing ozone oxidation catalysts are suitable for the present invention, such as the catalysts disclosed in patents CN117583013A, CN117181242A, CN117101656A, and CN116586052A.

[0055] Furthermore, in step (1), the mass ratio of copper oxide to alkali slag is 0.025-0.05, the temperature of the desulfurization reaction is 20-30° C., and the reaction time is 20-30 min.

[0056] Furthermore, in step (2), the mass ratio of alkali residue to CO2 gas is 20 to 80, the pH value of the alkali residue after neutralization is 9 to 10, the neutralization reaction temperature is 25 to 40°C, and the neutralization reaction time is not less than 2 hours.

[0057] Furthermore, the carbonization tower is composed of two towers connected in series; the alkali slag after desulfurization is pumped into the kettle from the top of the first carbonization tower, and the alkali slag at the bottom of the first carbonization tower is pumped into the kettle from the top of the second carbonization tower via an alkali slag conveying pump; fresh CO2 gas for neutralization enters the flask from the bottom of the second carbonization tower to neutralize with the alkali slag, and the neutralized CO2 gas enters the flask from the bottom of the first carbonization tower via an induced draft fan, and the neutralized CO2 tail gas is extracted through the tail gas induced draft fan at the top of the first carbonization tower and discharged into the tail gas main pipe.

[0058] Furthermore, in step (3), the oxidation tower is filled with a catalyst, the mass ratio of alkali residue to ozone is 20-30, the mass ratio of alkali residue to hydrogen peroxide is 50-150, and the liquid space velocity of the alkali residue flowing through the catalyst bed is 5-20h -1 The oxidation reaction temperature is 30±10℃ and the oxidation reaction time is not less than 2 hours.

[0059] Furthermore, the oxidation tower is composed of two towers connected in series, and the towers are equipped with fillers and catalysts; the neutralized alkali slag liquid is pumped into the kettle from the bottom of the first oxidation tower, and the oxidized alkali slag liquid overflows from the upper part of the first oxidation tower, and after sedimentation and separation, it is pumped into the kettle from the bottom of the second oxidation tower through an alkali slag conveying pump, and the oxidant enters the first oxidation tower and the second oxidation tower respectively.

[0060] Furthermore, in step (4), the mass ratio of calcium oxide to alkali residue is 0.2-0.3, the causticizing reaction temperature is 80-90° C., and the reaction time is 120±20 min.

[0061] Furthermore, in step (5), the alkali concentration in the absorption liquid is 5 to 15% in terms of sodium oxide; the volume flow rate of the tail gas entering the absorption liquid is 0.1 to 1 m 3 / min, the absorption temperature is 20~30℃.

[0062] Another object of the present invention is to provide a treatment system for a refinery alkali slag resource treatment process, comprising a desulfurization unit, a neutralization unit, a refining unit, an alkali recovery unit and a tail gas treatment unit;

[0063] The desulfurization unit is used to desulfurize the alkali residue in the desulfurization reactor using copper oxide as a precipitant, thereby removing the sulfur-containing components;

[0064] The neutralization unit is used to use CO2 gas as a neutralizing agent to neutralize the desulfurized alkali slag in the carbonization tower, thereby separating crude phenol and a small amount of organic matter;

[0065] The refining unit is used to use ozone and hydrogen peroxide as oxidants to perform ozone catalytic oxidation on the neutralized alkali residue in the oxidation tower, thereby further reducing the content of organic matter and sulfide in the alkali residue;

[0066] The alkali recovery unit is used to causticize the alkali residue with calcium oxide, recover sodium hydroxide from the alkali residue, and achieve salt-free discharge;

[0067] The tail gas treatment unit is used to collect waste gas generated by the desulfurization unit, the neutralization unit, the refining unit and the alkali recovery unit, and the waste gas is absorbed by the absorption liquid and then discharged into the atmosphere.

[0068] Furthermore, the desulfurization unit comprises an alkali residue tank, a first alkali residue delivery pump, a desulfurization reactor, a butterfly centrifuge and a desulfurization residue recovery tank. The alkali residue in the alkali residue tank is pumped into the desulfurization reactor by the first alkali residue delivery pump for desulfurization reaction. After the desulfurization reaction, the alkali residue is separated by the butterfly centrifuge, and the liquid phase enters the post-desulfurization alkali residue tank of the neutralization unit, and the solid phase enters the desulfurization residue recovery tank.

[0069] The neutralization unit includes a post-desulfurization alkali residue tank, a second alkali residue delivery pump, a CO2 storage bottle, a first carbonization tower, a third alkali residue delivery pump, a second carbonization tower, a second carbonization tower top induced draft fan, a sedimentation tank, a first sedimentation liquid separation tank, a fourth alkali residue delivery pump and a first crude phenol delivery pump;

[0070] The alkali residue in the desulfurization residue recovery tank is pumped from the top of the first carbonization tower into the kettle through the second alkali residue conveying pump, and undergoes a neutralization reaction with the fresh CO2 gas in the CO2 storage bottle entering from the bottom of the second carbonization tower. The alkali residue after the neutralization reaction at the bottom of the first carbonization tower is pumped from the top of the second carbonization tower into the kettle through the second alkali residue conveying pump, and undergoes a secondary neutralization reaction with the CO2 gas after the neutralization reaction introduced from the top of the first carbonization tower through the second carbonization tower induced draft fan. The alkali residue after the secondary neutralization reaction at the bottom of the second carbonization tower enters the sedimentation tank, and after sedimentation, the water phase first enters the carbonized alkali residue tank of the refining unit, and the oil phase enters the first sedimentation liquid separation tank for sedimentation and separation. The separated water phase is sent to the crude phenol recovery process through the first crude phenol conveying pump, and the oil phase is sent to the carbonized alkali residue tank through the fourth alkali residue conveying pump;

[0071] The refining unit includes a carbonized alkali residue tank, a fifth alkali residue delivery pump, a first oxidation tower, an ozone station, an oxidation synergist barrel, an oxidation synergist metering pump, a second sedimentation and separation tank, a sixth alkali residue delivery pump, a second oxidation tower and a second crude phenol delivery pump;

[0072] The hydrogen peroxide in the oxidation synergist barrel enters the first oxidation tower and the second oxidation tower from the bottom of the tower respectively through the oxidation synergist metering pump, the ozone from the ozone station enters the first oxidation tower and the second oxidation tower from the bottom of the tower respectively, the alkali residue in the carbonized alkali residue can is pumped from the bottom of the tower into the first oxidation tower kettle through the fifth alkali residue conveying pump for catalytic oxidation reaction with hydrogen peroxide and ozone, the oxidized alkali residue overflowing from the top of the first oxidation tower enters the second sedimentation liquid separation tank for sedimentation separation, the separated water phase is conveyed to the crude phenol recovery process through the second crude phenol conveying pump, the oil phase is pumped from the bottom of the tower into the second oxidation tower through the sixth alkali residue conveying pump for secondary catalytic oxidation reaction, and the secondary oxidized alkali residue overflowing from the top of the second oxidation tower enters the oxidized alkali residue can of the alkali recovery unit;

[0073] The alkali recovery unit includes an oxidized alkali residue tank, a seventh alkali residue delivery pump, a recovery reactor, a recovery liquid delivery pump, a first plate-frame filter, a sodium hydroxide recovery tank, a sodium hydroxide delivery pump, a first filter residue tray, a filter residue washing tank, a filter residue liquid delivery pump, a second plate-frame filter, a second filter residue tray and a filter residue receiving tank;

[0074] The alkali residue in the alkali residue can after oxidation is pumped into the recovery reactor through the seventh alkali residue delivery pump to react with calcium oxide causticization, the alkali residue after the reaction in the recovery reactor is pumped into the first plate-frame filter through the recovery liquid delivery pump for squeezing and separation, the filtrate after separation enters the sodium hydroxide recovery can, the filter residue after separation is cleaned into the first filter residue material tray, and then sent to the filter residue washing kettle for water washing, the filter residue after water washing is pressed and delivered to the second plate-frame filter through the filter residue liquid delivery pump, the filtrate in the second plate-frame filter is sent to the absorbent barrel of the tail gas treatment unit as an absorption liquid for storage, the filter residue is cleaned into the second filter residue material tray, and then discharged to the filter residue receiving tank;

[0075] The tail gas treatment unit includes: a tail gas absorption tank, an absorbent barrel, an absorbent delivery pump, an absorbent discharge pump, an oxidation tower top tail gas induced draft fan, a first carbonization tower top tail gas induced draft fan and a tail gas main induced draft fan;

[0076] The waste gas generated by the desulfurization unit and the alkali recovery unit is sucked into the tail gas main by the tail gas main induced draft fan, the waste gas generated by the neutralization unit is sucked into the tail gas main by the tail gas induced draft fan on the top of the oxidation tower, and the waste gas generated by the refining unit is sucked into the tail gas main by the tail gas induced draft fan on the top of the first carbonization tower. The tail gas in the tail gas main enters the tail gas absorption tank and is absorbed by the absorbent in the absorbent barrel pumped into the tail gas main by the absorbent delivery pump. The saturated absorption liquid in the tail gas absorption tank is sent to the alkali slag tank by the absorption liquid discharge pump.

[0077] Beneficial effects of the invention: The pollution-free resource treatment process for refinery alkali slag of the invention adopts a combination of multiple methods and uses a new process to organically combine multiple effective deep treatment and resource recovery technologies. The process has wider applicability, higher organic matter degradation rate, better effluent water quality, higher degree of resource utilization, and achieves waste-free discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a process flow chart for resource treatment of refinery alkali slag according to Example 1 of the present invention.

[0079] Among them, the desulfurization unit includes: 1.1, alkali residue can, 1.2, first alkali residue delivery pump, 1.3, desulfurization reactor, 1.4, butterfly centrifuge, 1.5, desulfurization residue recovery can;

[0080] Neutralization unit: 2.1, alkali residue can after desulfurization, 2.2, second alkali residue delivery pump, 2.3, CO2 storage bottle, 2.4, first carbonization tower, 2.5, third alkali residue delivery pump, 2.6, second carbonization tower, 2.7, second carbonization tower top induced draft fan, 2.8, sedimentation can (three), 2.9, first sedimentation liquid separation tank, 2.10, fourth alkali residue delivery pump, 2.11, first crude phenol delivery pump;

[0081] Refining unit: 3.1, carbonized alkali residue can, 3.2, fifth alkali residue delivery pump, 3.3, first oxidation tower, 3.4, ozone station, 3.5, oxidation synergist barrel, 3.6, oxidation synergist metering pump, 3.7, second sedimentation liquid tank (two), 3.8, sixth alkali residue delivery pump, 3.9, second oxidation tower, 3.10, second crude phenol delivery pump;

[0082] Recovery unit: 4.1, alkali residue can after oxidation, 4.2, seventh alkali residue delivery pump, 4.3, recovery reaction kettle, 4.4, recovery liquid delivery pump, 4.5, first plate and frame filter, 4.6, sodium hydroxide recovery can, 4.7, sodium hydroxide delivery pump, 4.8, first filter residue tray, 4.9, filter residue washing kettle, 4.10, filter residue liquid delivery pump, 4.11, second plate and frame filter, 4.12, second filter residue tray, 4.13, filter residue receiving tank;

[0083] Tail gas treatment unit: 5.1, tail gas absorption tank, 5.2, absorbent barrel, 5.3, absorbent delivery pump, 5.4, absorption liquid discharge pump, 5.5, oxidation tower top tail gas induced draft fan, 5.6, first carbonization tower top tail gas induced draft fan, 5.7, tail gas main induced draft fan. DETAILED DESCRIPTION

[0084] The invention is further described below in conjunction with the embodiments.

[0085] Example 1

[0086] See also Figure 1 , this embodiment discloses a refinery alkali slag resource processing system, including a desulfurization unit, a neutralization unit, a refining unit, an alkali recovery unit and a tail gas treatment unit;

[0087] The desulfurization unit comprises an alkali residue tank 1.1, a first alkali residue delivery pump 1.2, a desulfurization reactor 1.3, a butterfly centrifuge 1.4 and a desulfurization residue recovery tank 1.5. The alkali residue in the alkali residue tank 1.1 is pumped into the desulfurization reactor 1.3 through the first alkali residue delivery pump 1.2 for desulfurization reaction. After the desulfurization reaction, the alkali residue is separated by the butterfly centrifuge 1.4, and the liquid phase enters the post-desulfurization alkali residue tank 2.1 of the neutralization unit, and the solid phase enters the desulfurization residue recovery tank 1.5;

[0088] The neutralization unit includes a post-desulfurization alkali residue can 2.1, a second alkali residue delivery pump 2.2, a CO2 storage bottle 2.3, a first carbonization tower 2.4, a third alkali residue delivery pump 2.5, a second carbonization tower 2.6, a second carbonization tower top induced draft fan 2.7, a sedimentation can 2.8, a first sedimentation liquid separation tank 2.9, a fourth alkali residue delivery pump 2.10 and a first crude phenol delivery pump 2.11; the carbonization tower is a packed tower.

[0089] The alkali residue in the desulfurization slag recovery can 2.1 is pumped into the kettle from the top of the first carbonization tower 2.4 through the second alkali residue delivery pump 2.2, and is neutralized with the fresh CO2 gas in the CO2 storage bottle 2.3 entering from the bottom of the second carbonization tower 2.6. The alkali residue after the neutralization reaction at the bottom of the first carbonization tower 2.4 is pumped into the kettle from the top of the second carbonization tower 2.6 through the second alkali residue delivery pump 2.2, and is neutralized with the fresh CO2 gas from the CO2 storage bottle 2.3 entering from the bottom of the second carbonization tower 2.6. The CO2 gas introduced from the top of the tower after the neutralization reaction undergoes a secondary neutralization reaction, and the alkali residue after the secondary neutralization reaction at the bottom of the second carbonization tower 2.6 enters the sedimentation tank 2.8. After sedimentation, the water phase first enters the carbonized alkali residue tank 3.1 of the refining unit, and the oil phase enters the first sedimentation liquid separation tank 2.9 for sedimentation and separation. The separated water phase is sent to the crude phenol recovery process via the first crude phenol delivery pump 2.11, and the oil phase is sent to the carbonized alkali residue tank 3.1 via the fourth alkali residue delivery pump 2.10;

[0090] The refining unit includes a carbonized alkali residue can 3.1, a fifth alkali residue delivery pump 3.2, a first oxidation tower 3.3, an ozone station 3.4, an oxidation synergist barrel 3.5, an oxidation synergist metering pump 3.6, a second sedimentation and liquid separation tank 3.7, a sixth alkali residue delivery pump 3.8, a second oxidation tower 3.9 and a second crude phenol delivery pump 3.10; the first oxidation tower 3.3 and the second oxidation tower 3.9 are both filled with catalysts. In this embodiment, the catalyst is a palladium alumina catalyst (0-5%) purchased from Xi'an Kaili New Materials Co., Ltd., and its loading amount is 60kg.

[0091] The hydrogen peroxide in the oxidation synergist barrel 3.5 enters the first oxidation tower 3.3 and the second oxidation tower 3.9 from the bottom of the tower respectively through the oxidation synergist metering pump 3.6, and the ozone from the ozone station 3.4 enters the first oxidation tower 3.3 and the second oxidation tower 3.9 from the bottom of the tower respectively. The alkali residue in the carbonized alkali residue can 3.1 is pumped from the bottom of the tower into the kettle of the first oxidation tower 3.3 through the fifth alkali residue delivery pump 3.2 for catalytic oxidation reaction with hydrogen peroxide and ozone. The oxidized alkali residue overflowing from the top of the first oxidation tower 3.3 enters the second sedimentation liquid separation tank 3.7 for sedimentation and separation. After separation, the aqueous phase is delivered to the crude phenol recovery process through the second crude phenol delivery pump 3.10, and the oil phase is pumped from the bottom of the tower into the second oxidation tower 3.9 through the sixth alkali residue delivery pump 3.8 for secondary catalytic oxidation reaction. The secondary oxidized alkali residue overflowing from the top of the second oxidation tower 3.9 enters the oxidized alkali residue can 4.1 of the alkali recovery unit;

[0092] The alkali recovery unit comprises an oxidized alkali residue can 4.1, a seventh alkali residue delivery pump 4.2, a recovery reactor 4.3, a recovery liquid delivery pump 4.4, a first plate-frame filter 4.5, a sodium hydroxide recovery can 4.6, a sodium hydroxide delivery pump 4.7, a first filter residue tray 4.8, a filter residue washing tank 4.9, a filter residue liquid delivery pump 4.10, a second plate-frame filter 4.11, a second filter residue tray 4.12 and a filter residue receiving tank 4.13;

[0093] The alkali residue in the oxidized alkali residue can 4.1 is pumped into the recovery reactor 4.3 through the seventh alkali residue delivery pump 4.2 for causticization reaction with calcium oxide. The alkali residue after reaction in the recovery reactor 4.3 is pumped into the first plate-frame filter 4.5 for squeezing and separation through the recovery liquid delivery pump 4.4. The filtrate after separation enters the sodium hydroxide recovery can 4.6. The filter residue after separation is cleaned into the first filter residue material tray 4.8 and then sent to the filter residue washing kettle 4.9 for water washing. After washing, the filter residue is pressed and delivered to the second plate-frame filter 4.11 through the filter residue liquid delivery pump 4.10. The filtrate in the second plate-frame filter 4.11 is sent to the absorbent material barrel 5.2 of the tail gas treatment unit as an absorption liquid for storage. The filter residue is cleaned into the second filter residue material tray 4.12 and then discharged to the filter residue receiving tank 4.13.

[0094] The tail gas treatment unit comprises: a tail gas absorption tank 5.1, an absorbent barrel 5.2, an absorbent delivery pump 5.3, an absorption liquid discharge pump 5.4, an oxidation tower top tail gas induced draft fan 5.5, a first carbonization tower top tail gas induced draft fan 5.6 and a tail gas main induced draft fan 5.7;

[0095] The waste gas generated in the alkali residue tank 1.1, the desulfurization residue recovery tank 1.5, the desulfurized alkali residue tank 2.1, the first sedimentation separation tank 2.9, the carbonized alkali residue tank 3.1, the second sedimentation separation tank 3.7, the oxidized alkali residue tank 4.1 and the sodium hydroxide recovery tank 4.6 is sucked to the tail gas main pipe by the exhaust main pipe induced draft fan 5.7, and the waste gas generated in the first oxidation tower 3.3 and the second oxidation tower 3.9 is sucked to the tail gas main pipe by the exhaust induced draft fan 5.7. The CO2 tail gas in the first carbonization tower 2.4 is sucked to the tail gas main pipe by the tail gas induced draft fan 5.6 at the top of the first carbonization tower, and the tail gas in the tail gas main pipe enters the tail gas absorption tank 5.1, the absorbent in the absorbent barrel 5.2 is pumped into the tail gas absorption tank 5.1 by the absorbent delivery pump 5.3, and the saturated absorption liquid in the tail gas absorption tank (5.1) is delivered to the alkali residue can 1.1 by the absorption liquid discharge pump 5.4.

[0096] Example 2

[0097] See also Figure 1 The raw material is the desulfurized alkali residue from the refining of liquid hydrocarbons of Sinopec Jinling Petrochemical Co., Ltd. The COD of the raw material is 9.51×10 4 mg / L, sulfur content is 3.86×10 3 mg / L, phenol content is 8.91×10 3 mg / L; the processing system described in Example 1 is used to process the raw materials for resource recovery, and the specific steps are as follows:

[0098] The first alkali slag delivery pump 1.2 is used to pump 500 kg of alkali slag in the alkali slag can 1.1 into the desulfurization reactor 1.3 after metering. Under stirring (stirring speed 120r / min), 17.5 kg of copper oxide is added, and the mass ratio of copper oxide to alkali slag is 0.035. The reaction is carried out at 25°C for 20 minutes, and the reacted material is continuously pumped into the butterfly centrifuge 1.4. After high-speed centrifugation in the butterfly centrifuge, the sulfide is removed, and the relatively clear material (water phase) is discharged from the upper discharge port of the centrifuge and enters the desulfurized alkali slag can 2.1; the sediment turbid phase (solid phase) is discharged from the lower discharge port of the centrifuge and enters the desulfurized slag recovery can 1.5. The sulfur content of the alkali slag in the desulfurized alkali slag can 2.1 is detected to be 62.11 mg / L, and the sulfide removal rate is 98.39%.

[0099] The alkali residue liquid in the alkali residue tank 2.1 after desulfurization is pumped into the first carbonization tower 2.4 from the top of the tower at a flow rate of 1000kg / h by the second alkali residue delivery pump 2.2, and neutralizes with the rising CO2 gas in the packing layer of the carbonization tower; the alkali residue liquid dropped to the bottom of the tower is sent to the second carbonization tower 2.6 from the top of the tower by the third alkali residue delivery pump 2.5 at a flow rate of 1000kg / h, and neutralizes with the rising fresh CO2 gas between the packings. The alkali residue liquid at the bottom of the second carbonization tower 2.6 is sent to the sedimentation tank 2.8 for static precipitation. Fresh CO2 gas for neutralization enters the flask from the bottom 2.6 of the second carbonization tower at a flow rate of 18 kg / h through the CO2 storage bottle 2.3. The neutralized CO2 gas enters the flask from the bottom of the first carbonization tower at a flow rate of 18 kg / h through the second carbonization tower induced draft fan 2.7. The neutralized CO2 tail gas is extracted through the tail gas induced draft fan at the top of the first carbonization tower and discharged into the tail gas main pipe.

[0100] The neutralization reaction temperature of the first carbonization tower 2.4 and the second carbonization tower 2.6 are both controlled at 30° C., the neutralization reaction time is both controlled at two hours, and the pH value of the material after the neutralization reaction is controlled at about 9.5.

[0101] The neutralized material is statically separated and separated in the sedimentation tank 2.8 for three hours. The upper oil phase is mainly crude phenol, and the lower water phase mainly contains sodium carbonate and sodium bicarbonate. The water phase is first cut into the carbonized alkali residue tank 3.1, and the oil phase is cut into the sedimentation liquid separation tank 2.9 for further separation. After separation, the water phase is pumped into the carbonized alkali residue tank 3.1 through the fourth alkali residue delivery pump 2.10, and the oil phase is delivered through the first crude phenol delivery pump 2.11 to remove the phenol recovery process.

[0102] The alkali residue liquid in the carbonized alkali residue tank 3.1 is pumped into the first oxidation tower 3.3 from the bottom of the tower at a flow rate of 1000kg / h by the fifth alkali residue delivery pump 3.2 after metering, mixed with the oxidation synergist and ozone, passed through the catalyst bed, and completed an oxidation reaction at a certain air velocity. The oxidized alkali residue liquid overflows from the upper part of the tower into the second sedimentation liquid separation tank 3.7 for two hours of static stratification. The slag liquid in the second sedimentation liquid separation tank 3.7 is then pumped from the lower part of the tower into the second oxidation tower 3.9 at a flow rate of 1000kg / h by the sixth alkali residue delivery pump 3.8, mixed with the oxidation synergist and ozone, passed through the catalyst bed, and completed a secondary oxidation reaction at a certain air velocity. The alkali residue liquid after secondary oxidation overflows from the upper part of the tower into the oxidized alkali residue tank 4.1.

[0103] Ozone is provided by the ozone station 3.4, and after metering, it enters the first oxidation tower 3.3 and the second oxidation tower 3.9 through a dedicated pipeline at a flow rate of 45 kg / h. The oxidizing synergist is stored in the oxidizing synergist barrel 3.5, and after metering by the oxidizing synergist metering pump 3.6, it enters the first oxidation tower 3.3 and the second oxidation tower 3.9 through a dedicated pipeline at a flow rate of 10 kg / h. The oxidized tail gas is extracted at the top of the two oxidation towers through the tail gas induced draft fan 5.5 at the top of the oxidation towers and discharged into the tail gas main pipe.

[0104] The oxidation reaction temperature of the first oxidation tower 3.3 and the second oxidation tower 3.9 were both controlled at 30°C, and the oxidation time was two hours; in the first oxidation tower 3.3 and the second oxidation tower 3.9, the mass ratio of alkali residue to ozone was 22.2, the mass ratio of alkali residue to hydrogen peroxide was 100, and the liquid space velocity of alkali residue flowing through the catalyst bed was 16.67h -1 .

[0105] After the materials in the second sedimentation and separation tank 3.7 are static and separated into layers, the upper layer contains a small amount of oil phase, which is mainly crude phenol. It is sent out through the second crude phenol delivery pump 3.10 to the phenol recovery process.

[0106] The seventh alkali residue delivery pump 4.2 is used to pump the metered 1000kg refined alkali residue liquid from the oxidized alkali residue can 4.1 into the recovery reactor 4.3, and 250kg calcium oxide is added under stirring, and the reaction time is 2h at 85℃, and then the recovery liquid delivery pump 4.4 is pressed to the first plate-frame filter 4.5. The pressure of the first plate-frame filter 4.5 is 0.7MPa. The filtrate generated during the filtration process is a NaOH solution with a mass concentration of 16.85%, which enters the sodium hydroxide recovery can 4.6 for storage and can be transported to other processes for recycling through the sodium hydroxide delivery pump 4.7. After 0.5 hours of filtration, the filter residue with a water content of 50% is cleaned into the first filter residue material tray 4.8, and then sent to the filter residue cleaning kettle 4.9 for water washing to remove NaOH. After a period of water washing, the filter residue liquid delivery pump 4.10 is pressed to the second plate-frame filter 4.11. The pressure of the second plate and frame filter 4.11 is 1MPa. Part of the filtrate produced during the filtration process is sent to the tail gas recovery unit as tail gas absorption liquid, and part is reused as cleaning liquid. After 1 hour of filtration, the filter residue with a water content of 20% is cleaned into the second filter residue material tray 4.12 and then discharged to the filter residue receiving tank 4.13. At this time, the main component of the filter residue is calcium carbonate, which can be recycled. The COD content in the sodium hydroxide recovery can 4.6 is 5.16×10 3 mg / L, the sulfur content is 82.60 mg / L, the salt content is 0.98%, the COD removal rate of alkali slag waste liquid is 94.57%, and the volatile phenol removal rate is 97.86%.

[0107] The absorbent stored in the barrel 5.2 is stored at 0.5 m 3 / min flow rate is pumped into the tail gas absorption tank 5.1 through the delivery pump 5.3 to absorb the exhaust gas from the above units. The volume flow rate of the exhaust gas entering the absorption liquid is controlled to be 2L / min, and the absorption temperature is 25℃. Detection of nitrogen oxides (NO X ), sulfur dioxide (SO2), carbon monoxide (CO), chlorine (Cl2), ammonia (NH3) and volatile organic compounds (VOCs) contents are shown in Table 1 below. The exhaust gas detection instrument is a portable composite multi-parameter gas analyzer ERUN-QB9610.

[0108] Table 1 Exhaust gas pollutant detection results

[0109]

[0110] When the alkali concentration in the absorption liquid is less than 5% in terms of sodium oxide, it is delivered to the alkali residue tank 1.1 of the desulfurization unit by the absorption liquid discharge pump 5.4 for circulation treatment.

[0111] Example 3

[0112] The process flow is the same as that of Example 2, except that:

[0113] The raw material COD is 9.04×10 4 mg / L, sulfur content is 3.15×10 3 mg / L, phenol content is 8.23×10 3 mg / L.

[0114] In the desulfurization unit, the mass ratio of copper oxide to alkali slag is 0.025, the temperature of the desulfurization reaction is 20°C, and the reaction time is 30 minutes. The sulfur content of the alkali slag after desulfurization is 60.12 mg / L, and the sulfide removal rate is 98.09%.

[0115] In the neutralization unit, the mass ratio of alkali residue to CO2 gas is 66.67, the neutralization reaction temperature is 25°C, and the neutralization reaction time is 2 hours.

[0116] In the refining unit, the oxidation reaction temperature of the first oxidation tower 3.3 and the second oxidation tower 3.9 were both controlled at 20°C, and the oxidation time was 2 hours; the mass ratio of alkali residue to ozone was 28.57, the mass ratio of alkali residue to hydrogen peroxide was 125, and the liquid space velocity of alkali residue flowing through the catalyst bed was 5h -1 .

[0117] The mass ratio of calcium oxide to alkali slag is 0.3, the causticizing reaction temperature is 80°C, and the reaction time is 140 minutes.

[0118] The COD content in the sodium hydroxide recovery can 4.6 was 4.88×10 3mg / L, the sulfur content is 79.93 mg / L, the salt content is 0.95%, the COD removal rate of alkali slag waste liquid is 94.57%, and the volatile phenol removal rate is 98.13%.

[0119] The alkali concentration in the absorption liquid is 5% in terms of sodium oxide; the volume flow rate of tail gas entering the absorption liquid is 0.1m 3 / min, the absorption temperature is 20℃. Detection of NO in the exhaust gas after being treated by the absorption liquid X Content <0.1mg / m 3 、SO2 content <0.5mg / m 3 , VOCs content <1ppm.

[0120] Example 4

[0121] The process flow is the same as that of Example 2, except that:

[0122] The raw material COD is 9.89×10 4 mg / L, sulfur content is 4.58×10 3 mg / L, phenol content is 9.46×10 3 mg / L.

[0123] In the desulfurization unit, the mass ratio of copper oxide to alkali slag is 0.05, the temperature of the desulfurization reaction is 30°C, and the reaction time is 20 minutes. The sulfur content of the alkali slag after desulfurization is 65.33 mg / L, and the sulfide removal rate is 98.57%.

[0124] In the neutralization unit, the mass ratio of alkali slag to CO2 gas is 40, the neutralization reaction temperature is 40°C, and the neutralization reaction time is 2 hours.

[0125] In the refining unit, the oxidation reaction temperature of the first oxidation tower 3.3 and the second oxidation tower 3.9 were both controlled at 40°C, and the oxidation time was 2 hours; the mass ratio of alkali residue to ozone was 20, the mass ratio of alkali residue to hydrogen peroxide was 75, and the liquid space velocity of alkali residue flowing through the catalyst bed was 5h -1 .

[0126] The mass ratio of calcium oxide to alkali residue is 0.2, the causticizing reaction temperature is 90°C, and the reaction time is 100 min.

[0127] The COD content in the sodium hydroxide recovery can 4.6 was 5.56×10 3 mg / L, the sulfur content is 87.21 mg / L, the salt content is 0.96%, the COD removal rate of alkali slag waste liquid is 94.38%, and the volatile phenol removal rate is 97.64%.

[0128] The alkali concentration in the absorption liquid is 15% in terms of sodium oxide; the volume flow rate of tail gas entering the absorption liquid is 1m 3 / min, the absorption temperature is 30℃. Detection of NO in the exhaust gas after being treated by the absorption liquid X Content <0.1mg / m 3 、SO2 content <0.5mg / m 3 , VOCs content <1ppm.

Claims

1. A refinery alkali slag resource treatment process, characterized in that: The steps include: (1) First, the alkali residue is fed into a desulfurization unit, and copper oxide is used as a precipitant in a desulfurization reactor to desulfurize the alkali residue. After the desulfurization product is centrifuged, the clarified liquid enters a neutralization unit, and the precipitate is sent to a copper oxide recovery unit to recover copper oxide; (2) In the neutralization unit, CO2 gas is used as a neutralizing agent to neutralize the desulfurized alkali residue in a carbonization tower. After the neutralization product is separated by sedimentation, the oil phase is sent to the phenol recovery process to recover the crude phenol, and the water phase enters the refining unit; (3) In the refining unit, ozone and hydrogen peroxide are used as oxidants to perform ozone catalytic oxidation on the neutralized alkali residue in an oxidation tower, and the tail gas generated during the oxidation process is sent to a tail gas recovery unit. After the oxidation product is separated by sedimentation, the oil phase is sent to a phenol recovery process to recover crude phenol, and the water phase enters an alkali recovery unit; (4) In the alkali recovery unit, the refined alkali residue is causticized using calcium oxide. After the causticization reaction product is separated by squeezing, the solid phase is sent to the recovery unit to recover sodium hydroxide and calcium carbonate, and the liquid phase is sent to the tail gas treatment unit as an absorption liquid; (5) The waste gas generated by the desulfurization unit, neutralization unit, refining unit and alkali recovery unit enters the tail gas treatment unit, is absorbed by the absorbent and then discharged into the atmosphere, and the saturated absorption liquid is sent to the desulfurization unit and recycled together with the alkali slag.

2. A refinery alkali slag resource treatment process according to claim 1, characterized in that: In step (1), the mass ratio of copper oxide to alkali residue is 0.025-0.05, the temperature of the desulfurization reaction is 20-30° C., and the reaction time is 20-30 min.

3. The refinery alkali slag resource treatment process according to claim 1, characterized in that: In step (2), the mass ratio of alkali residue to CO2 is 20-80, the pH value of the alkali residue after neutralization is 9-10, the neutralization reaction temperature is 25-40°C, and the neutralization reaction time is not less than 2 hours.

4. A refinery alkali slag resource treatment process according to claim 3, characterized in that: The carbonization tower is composed of two towers connected in series; the alkali slag after desulfurization is pumped into the tower kettle from the top of the first carbonization tower, and the alkali slag at the bottom of the first carbonization tower is pumped into the tower kettle from the top of the second carbonization tower through an alkali slag conveying pump; fresh CO2 gas for neutralization enters the tower kettle from the bottom of the second carbonization tower to neutralize with the alkali slag, and the neutralized CO2 gas enters the tower kettle from the bottom of the first carbonization tower through an induced draft fan, and the neutralized CO2 tail gas is extracted through the tail gas induced draft fan at the top of the first carbonization tower and discharged into the tail gas main pipe.

5. The refinery alkali slag resource treatment process according to claim 1, characterized in that: In step (3), the oxidation tower is filled with a catalyst, the mass ratio of alkali residue to ozone is 20-30, the mass ratio of alkali residue to hydrogen peroxide is 50-150, and the liquid space velocity of the alkali residue flowing through the catalyst bed is 5-20h -1 , the oxidation reaction temperature is 30±10℃, and the oxidation reaction time is not less than 2 hours.

6. A refinery alkali slag resource treatment process according to claim 5, characterized in that: The oxidation tower is composed of two towers connected in series, and fillers and catalysts are installed in the towers; the neutralized alkali slag liquid is pumped into the tower kettle from the bottom of the first oxidation tower, and the oxidized alkali slag liquid overflows from the upper part of the first oxidation tower, and is pumped into the tower kettle from the bottom of the second oxidation tower through an alkali slag conveying pump after sedimentation and separation, and the oxidant enters the first oxidation tower and the second oxidation tower respectively.

7. The refinery alkali slag resource treatment process according to claim 1, characterized in that: In step (4), the mass ratio of calcium oxide to alkali residue is 0.2-0.3, the causticizing reaction temperature is 80-90° C., and the reaction time is 120±20 min.

8. The refinery alkali slag resource treatment process according to claim 1, characterized in that: In step (5), the alkali concentration in the absorption liquid is 5-15% in terms of sodium oxide; the volume flow rate of the tail gas entering the absorption liquid is 0.1-1m 3 / min, the absorption temperature is 20~30℃.

9. A treatment system for a refinery alkali slag resource treatment process, characterized in that: It includes desulfurization unit, neutralization unit, refining unit, alkali recovery unit and tail gas treatment unit; The desulfurization unit is used to desulfurize the alkali residue in the desulfurization reactor using copper oxide as a precipitant, thereby removing the sulfur-containing components; The neutralization unit is used to use CO2 gas as a neutralizing agent to neutralize the desulfurized alkali slag in the carbonization tower, thereby separating crude phenol and a small amount of organic matter; The refining unit is used to use ozone and hydrogen peroxide as oxidants to perform ozone catalytic oxidation on the neutralized alkali residue in the oxidation tower, thereby further reducing the content of organic matter and sulfide in the alkali residue; The alkali recovery unit is used to causticize the alkali residue with calcium oxide, recover sodium hydroxide from the alkali residue, and achieve salt-free discharge; The tail gas treatment unit is used to collect waste gas generated by the desulfurization unit, the neutralization unit, the refining unit and the alkali recovery unit, and the waste gas is absorbed by the absorption liquid and then discharged into the atmosphere.

10. The processing system according to claim 9, characterized in that The desulfurization unit comprises an alkali residue can (1.1), a first alkali residue delivery pump (1.2), a desulfurization reactor (1.3), a butterfly centrifuge (1.4) and a desulfurization residue recovery can (1.5). The alkali residue in the alkali residue can (1.1) is pumped into the desulfurization reactor (1.3) by the first alkali residue delivery pump (1.2) to carry out a desulfurization reaction. After the desulfurization reaction, the alkali residue is separated by the butterfly centrifuge (1.4). The liquid phase enters the post-desulfurization alkali residue can (2.1) of the neutralization unit, and the solid phase enters the desulfurization residue recovery can (1.5). The neutralization unit comprises a post-desulfurization alkali residue can (2.1), a second alkali residue delivery pump (2.2), a CO2 storage bottle (2.3), a first carbonization tower (2.4), a third alkali residue delivery pump (2.5), a second carbonization tower (2.6), a second carbonization tower top induced draft fan (2.7), a sedimentation can (2.8), a first sedimentation liquid separation tank (2.9), a fourth alkali residue delivery pump (2.10) and a first crude phenol delivery pump (2.11); The alkali residue in the desulfurization slag recovery can (2.1) is pumped from the top of the first carbonization tower (2.4) into the tower kettle through the second alkali residue delivery pump (2.2), and undergoes a neutralization reaction with the fresh CO2 gas in the CO2 storage bottle (2.3) entering from the bottom of the second carbonization tower (2.6). The alkali residue after the neutralization reaction at the bottom of the first carbonization tower (2.4) is pumped from the top of the second carbonization tower (2.6) into the tower kettle through the second alkali residue delivery pump (2.2), and undergoes a neutralization reaction with the fresh CO2 gas in the CO2 storage bottle (2.3) entering from the bottom of the second carbonization tower (2.6). .4) The CO2 gas introduced from the top of the tower after the neutralization reaction is subjected to a secondary neutralization reaction, and the alkali residue after the secondary neutralization reaction at the bottom of the second carbonization tower (2.6) enters the sedimentation tank (2.8), and the water phase after sedimentation first enters the carbonized alkali residue tank (3.1) of the refining unit, and the oil phase enters the first sedimentation liquid separation tank (2.9) for sedimentation and separation, and the separated water phase is sent to the crude phenol recovery process via the first crude phenol delivery pump (2.11), and the oil phase is sent to the carbonized alkali residue tank (3.1) via the fourth alkali residue delivery pump (2.10); The refining unit includes a carbonized alkali residue can (3.1), a fifth alkali residue delivery pump (3.2), a first oxidation tower (3.3), an ozone station (3.4), an oxidation synergist barrel (3.5), an oxidation synergist metering pump (3.6), a second sedimentation and liquid separation tank (3.7), a sixth alkali residue delivery pump (3.8), a second oxidation tower (3.9) and a second crude phenol delivery pump (3.10); The hydrogen peroxide in the oxidation synergist barrel (3.5) enters the first oxidation tower (3.3) and the second oxidation tower (3.9) from the bottom of the tower respectively through the oxidation synergist metering pump (3.6), the ozone from the ozone station (3.4) enters the first oxidation tower (3.3) and the second oxidation tower (3.9) from the bottom of the tower respectively, and the alkali residue in the carbonized alkali residue can (3.1) is pumped from the bottom of the tower into the kettle of the first oxidation tower (3.3) through the fifth alkali residue delivery pump (3.2) to mix with the hydrogen peroxide and ozone. Catalytic oxidation reaction, the oxidized alkali residue overflowing from the top of the first oxidation tower (3.3) enters the second sedimentation separation tank (3.7) for sedimentation separation, the separated water phase is sent to the crude phenol recovery process through the second crude phenol delivery pump (3.10), the oil phase is pumped from the bottom of the tower into the second oxidation tower (3.9) through the sixth alkali residue delivery pump (3.8) for secondary catalytic oxidation reaction, and the secondary oxidized alkali residue overflowing from the top of the second oxidation tower (3.9) enters the oxidized alkali residue tank (4.1) of the alkali recovery unit; The alkali recovery unit comprises an oxidized alkali residue can (4.1), a seventh alkali residue delivery pump (4.2), a recovery reaction kettle (4.3), a recovery liquid delivery pump (4.4), a first plate and frame filter (4.5), a sodium hydroxide recovery can (4.6), a sodium hydroxide delivery pump (4.7), a first filter residue tray (4.8), a filter residue washing kettle (4.9), a filter residue liquid delivery pump (4.10), a second plate and frame filter (4.11), a second filter residue tray (4.12) and a filter residue receiving tank (4.13); The alkali residue in the oxidized alkali residue can (4.1) is pumped into the recovery reactor (4.3) through the seventh alkali residue delivery pump (4.2) for causticization reaction with calcium oxide. The alkali residue after reaction in the recovery reactor (4.3) is pumped into the first plate-frame filter (4.5) for squeezing and separation through the recovery liquid delivery pump (4.4). The filtrate after separation enters the sodium hydroxide recovery can (4.6). The filter residue after separation is cleaned into the first filter residue material tray (4.8), and then sent to the filter residue cleaning kettle (4.9) for water washing. After water washing, the filter residue is pressed and delivered to the second plate-frame filter (4.11) through the filter residue liquid delivery pump (4.10). The filtrate in the second plate-frame filter (4.11) is sent to the absorbent material barrel (5.2) of the tail gas treatment unit as an absorption liquid for storage. The filter residue is cleaned into the second filter residue material tray (4.12) and then discharged to the filter residue receiving tank (4.13); The tail gas treatment unit comprises: a tail gas absorption tank (5.1), an absorbent material barrel (5.2), an absorbent delivery pump (5.3), an absorption liquid discharge pump (5.4), an oxidation tower top tail gas induced draft fan (5.5), a first carbonization tower top tail gas induced draft fan (5.6) and a tail gas main induced draft fan (5.7); The waste gas generated by the desulfurization unit and the alkali recovery unit is sucked into the tail gas main pipe by the tail gas main pipe induced draft fan (5.7), the waste gas generated by the neutralization unit is sucked into the tail gas main pipe by the tail gas induced draft fan (5.5) at the top of the oxidation tower, and the waste gas generated by the refining unit is sucked into the tail gas main pipe by the tail gas induced draft fan (5.6) at the top of the first carbonization tower. The tail gas in the tail gas main pipe enters the tail gas absorption tank (5.1) and is absorbed by the absorbent in the absorbent barrel (5.2) pumped in by the absorbent delivery pump (5.3). The saturated absorption liquid in the tail gas absorption tank (5.1) is delivered to the alkali residue tank (1.1) by the absorption liquid discharge pump (5.4).

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