Catalytic cracking wastewater and waste gas cooperative treatment and resource recovery method and system

Abstract

The invention belongs to the field of catalytic cracking wastewater and waste gas treatment, and discloses a catalytic cracking wastewater and waste gas cooperative treatment and resource recovery method and system. The system comprises a heat exchanger, an incinerator, a dissolving unit, a tempering and carbonizing unit, an industrial sodium carbonate recycling unit, an industrial sodium sulfate recycling unit and a denitration unit. According to the invention, the problems of serious pollution discharge of alkaline residue wastewater and catalyst regeneration flue gas in the current catalytic cracking process, high consumption required by plant treatment and easy resource waste caused by the current treatment mode are solved, waste recycling is realized, and economic benefits and environmental benefits of the catalytic cracking process are improved.

Description

Technical Field

[0001] The present invention belongs to the field of catalytic cracking wastewater and waste gas treatment, and more specifically, relates to a method and system for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas. Background Art

[0002] The catalytic cracking process is an important production process in petrochemical industry. However, the process requires alkali liquid to flush the cracking gas, which produces a large amount of alkali residue wastewater. In addition, the catalytic cracking catalyst regeneration process produces a large amount of regeneration flue gas, which constitutes an important source of pollution in the catalytic cracking process. In order to improve the environmental protection of the refinery, the alkali residue wastewater is currently incinerated and the residue after incineration is outsourced as hazardous waste. The catalytic cracking catalyst regeneration flue gas needs to be equipped with independent dust removal, desulfurization and denitrification processes for purification and discharge. This has put tremendous pressure on the operating costs of the refinery.

[0003] The residue after incineration of alkali slag wastewater contains a large amount of salt resources. Outsourcing the treatment as hazardous waste not only increases the treatment cost but also causes a large amount of resource waste. There are many catalytic cracking catalyst regeneration flue gas treatment processes and there is currently a lack of CO2 treatment facilities. The installation of CO2 capture devices will increase the plant operation costs. In order to improve the economic benefits of the refinery, it is of great significance to achieve a more economical coordinated treatment process and solution for alkali slag wastewater and catalytic cracking regeneration flue gas.

[0004] CN105645441A discloses a method for preparing soda ash and anhydrous sodium sulfate by saponifying waste alkali liquor with cyclohexanone. The method includes evaporation concentration, incineration, dissolution, filtration, carbonization, drying, calcination, secondary dissolution, secondary filtration, cooling, and crystallization, and can separate and recover sodium carbonate and sodium sulfate. The method uses waste gas rich in CO2 (85-95%), and CO2 needs to be enriched. The amount of sulfuric acid required for the process to recover sodium sulfate is relatively high, the process cost is high, and the process economy needs to be further improved.

[0005] CN114432870A discloses a method and device for treating FCC regeneration flue gas. The invention sets up an adsorption unit to remove SO2, and the flue gas after desulfurization enters a microalgae cultivation unit to remove CO2 and NO by microalgae. x The SO2 resources in this invention have not been utilized, and the microalgae cultivation has low temperature requirements, and the flue gas waste heat is not used. It is necessary to further simplify the regeneration flue gas purification process and utilize the waste heat and SO2 resources. Summary of the invention

[0006] The purpose of the present invention is to address the serious pollution emissions of alkali residue wastewater and catalyst regeneration flue gas in the current catalytic cracking process, the high cost of plant area management, and the waste of resources caused by the current treatment method, and propose a method and system for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas. The present invention realizes waste resource utilization and improves the economic and environmental benefits of the catalytic cracking process.

[0007] In order to achieve the above-mentioned object, the present invention provides a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, the system comprising a heat exchanger, an incinerator, a dissolution unit, a tempering carbonization unit, an industrial sodium carbonate recovery unit, an industrial sodium sulfate recovery unit and a denitrification unit;

[0008] The heat exchanger includes a wastewater inlet, a waste gas inlet, a temperature-raising wastewater outlet, and a temperature-lowering waste gas outlet;

[0009] The incinerator comprises an incinerator inlet, an incineration residue outlet and an incineration smoke outlet;

[0010] The conditioning carbonization unit comprises a residual wastewater inlet, a mixed flue gas inlet, a sodium bicarbonate crystal outlet, a conditioning solution outlet and a conditioning gas outlet;

[0011] The industrial sodium carbonate recovery unit comprises a calcination unit and a first separation and recovery unit connected in sequence;

[0012] The industrial sodium sulfate recovery unit comprises an acidification unit, an ozone decolorization unit, an evaporation crystallization unit, a freezing crystallization unit and a second separation recovery unit connected in sequence;

[0013] The heated wastewater outlet is connected to the inlet of the incinerator; the cooled waste gas outlet and the incineration flue gas outlet are both connected to the mixed flue gas inlet; the incineration residue outlet is connected to the residue wastewater inlet through the dissolution unit; the sodium bicarbonate crystal outlet is connected to the calcination unit; the tempering solution outlet is connected to the acidification unit; and the tempering gas outlet pipeline is connected to the denitration unit.

[0014] In the present invention, the working principle of the tempering carbonization unit is that the residual wastewater and the mixed flue gas enter the unit, and the tempering process occurs at the front end of the unit, that is, the mixed flue gas heats the residual wastewater, and the SO2 and CO2 in the mixed flue gas are absorbed and enter the residual wastewater to adjust the pH, and in this process, the heating device also heats the residual wastewater, and the temperature of the residual wastewater reaches 30-50°C through the joint heating of the mixed flue gas and the heating device. After the temperature rises, the residual wastewater undergoes a carbonization process, and further absorbs the CO2 in the mixed flue gas to complete the carbonization process to obtain sodium bicarbonate crystals, and the sodium bicarbonate crystals + the tempered and carbonized solution + the tempered mixed flue gas are discharged at the outlet of the tempering carbonization unit.

[0015] According to the present invention, preferably, the system further comprises a denitration heat exchanger, wherein the denitration heat exchanger comprises a heat source inlet, a cold source inlet, a temperature-increasing material outlet and a temperature-reducing material outlet;

[0016] The incineration smoke outlet is connected to the heat source inlet; the cooling material outlet is connected to the mixed smoke inlet;

[0017] The tempering gas outlet is connected to the cold source inlet; the heating material outlet is connected to the denitration unit.

[0018] According to the present invention, preferably, the system further comprises a dust removal unit;

[0019] The cooling exhaust gas outlet and the incineration flue gas outlet are both connected to the dust removal unit, and the dust removal unit is connected to the mixed flue gas inlet through a mixed flue gas pipeline; or,

[0020] When a denitration heat exchanger is provided, the cooling exhaust gas outlet and the cooling material outlet are both connected to the dust removal unit, and the dust removal unit is connected to the mixed flue gas inlet via a mixed flue gas pipeline.

[0021] According to the present invention, preferably, the first separation and recovery unit is also connected to a calcination gas discharge pipeline and an industrial sodium carbonate product production pipeline;

[0022] The acidification unit is also connected to an acidification gas discharge pipeline;

[0023] The calcination gas discharge pipeline and the acidification gas discharge pipeline are connected to the mixed flue gas inlet;

[0024] The second separation and recovery unit is also connected to an industrial sodium sulfate product extraction pipeline;

[0025] The destocking unit is also connected to a clean flue gas discharge pipeline.

[0026] Another aspect of the present invention provides a method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, the method using the system comprises the following steps:

[0027] S1: exchanging heat between the alkali residue wastewater and the regeneration flue gas to obtain preheated alkali residue wastewater and cooled regeneration flue gas;

[0028] S2: incinerating the preheated alkali slag wastewater to obtain incineration residue and incineration flue gas; mixing the incineration flue gas with the cooled regeneration flue gas to obtain mixed flue gas;

[0029] S3: mixing the incineration residue with water to obtain residue wastewater; mixing the residue wastewater with the mixed flue gas and heating them to perform tempering and carbonization reactions to obtain sodium bicarbonate crystals, a tempering solution and a tempering gas;

[0030] S4: calcining and separating and recovering the sodium bicarbonate crystals in sequence to obtain an industrial sodium carbonate product and calcination gas;

[0031] S5: sequentially subjecting the conditioned solution to acidification, ozone decolorization, evaporation crystallization, freezing crystallization, and separation and recovery treatment to obtain an industrial sodium sulfate product;

[0032] S6: Denitrification and purification are performed on the tempered gas to achieve emission standards.

[0033] According to the present invention, preferably, in step S1:

[0034] The regeneration flue gas is waste flue gas from a heating boiler and / or regeneration flue gas from a catalytic cracking catalyst, and the components of the regeneration flue gas include SO2, CO2 and NO x ; The temperature of the regenerated flue gas is 300-500°C;

[0035] The temperature of the preheated alkali residue wastewater is 60-90°C;

[0036] The temperature of the cooled regeneration flue gas is 100-180°C.

[0037] In the present invention, the alkali residue wastewater is heat exchanged with the regeneration flue gas, so that the waste heat of the regeneration flue gas can be utilized as a resource, the heating energy consumption of the incinerator can be reduced, and the temperature of the regeneration flue gas can be reduced to meet the requirements of the dust removal equipment.

[0038] In the present invention, the preheated alkali residue waste water is incinerated to remove COD in the alkali residue waste water.

[0039] According to the present invention, preferably, in step S2:

[0040] The temperature of the incineration flue gas is 450-650°C;

[0041] The incineration flue gas is first heat exchanged with the tempering gas of step S6 to obtain cooled incineration flue gas and heated tempering gas; the cooled incineration flue gas is then mixed with the cooled regenerated flue gas to obtain mixed flue gas; the heated tempering gas is subjected to denitration purification treatment and is discharged in compliance with emission standards.

[0042] According to the present invention, preferably, in step S2:

[0043] The particle concentration of the mixed flue gas is less than 15 mg / m 3 ;

[0044] Alternatively, the mixed flue gas is subjected to dust removal treatment to obtain dust-removed mixed flue gas, and the residual wastewater is mixed with the dust-removed mixed flue gas and subjected to tempering and carbonization reactions to obtain sodium bicarbonate crystals, a tempering solution and a tempering gas.

[0045] In the present invention, the SO2 content of the mixed flue gas and the dust-removed mixed flue gas can be artificially regulated (the regulation method is a method well known to those skilled in the art. In the present invention, the regulation method includes: before the residual wastewater is mixed with the mixed flue gas, or before the residual wastewater is mixed with the dust-removed mixed flue gas, adding a SO2 content regulation unit to regulate the SO2 in the mixed flue gas or the dust-removed mixed flue gas). According to the present invention, preferably, the SO2 content of the mixed flue gas and the dust-removed mixed flue gas is independently 95-1205 mg / m 3 .

[0046] In the present invention, the CO2 content of the mixed flue gas and the dust-removed mixed flue gas can be artificially regulated (the regulation method is a method well known to those skilled in the art. In the present invention, the regulation method includes: before the residual waste water is mixed with the mixed flue gas, or before the residual waste water is mixed with the dust-removed mixed flue gas, a CO2 content regulation unit is added to regulate the CO2 in the mixed flue gas or the dust-removed mixed flue gas). According to the present invention, preferably, the CO2 content of the mixed flue gas and the dust-removed mixed flue gas is independently 7.5-16.5%.

[0047] According to the present invention, preferably, the temperature of the mixed flue gas is 250-450°C, and the temperature of the dust-removed mixed flue gas is 95-205°C.

[0048] According to the present invention, preferably, the volume mixing ratio of the mixed flue gas and the residual wastewater is (1-6.5):1; the mixing ratio of the dust removal mixed flue gas and the residual wastewater is (2-13):1.

[0049] According to the present invention, preferably, in step S3:

[0050] The water mixed with the incineration residue is distilled water;

[0051] The water quality conditions of the residual wastewater include: pH 7.8-12.2, mass concentration of Na2SO4 350-470g / L, mass concentration of Na2CO3 300-460g / L, mass concentration of metal elements 0.001-0.010g / L, mass concentration of NaOH 0-0.050g / L;

[0052] The temperature of the carbonization reaction is 30-50°C.

[0053] According to the present invention, preferably, in step S3:

[0054] The water quality conditions of the conditioning solution include: pH 7.5-8.5, mass concentration of sodium bicarbonate 80-100 g / L, mass concentration of sodium sulfate 360-480 g / L and mass concentration of sodium sulfite 1-5 g / L;

[0055] The SO2 content in the tempering gas is 30-50 mg / m 3 .

[0056] In the present invention, in step S3, the residual wastewater can absorb SO2 in the mixed flue gas to achieve flue gas desulfurization and adjust the pH of the residual wastewater, and at the same time, the CO2 in the mixed flue gas is utilized as a resource to complete the carbonization process. Therefore, the present invention saves the desulfurization equipment used to treat the regenerated flue gas, and at the same time, the residual wastewater is adjusted and adjusted, the amount of H2SO4 added in the subsequent step S5 acidification is reduced, and the process operation cost is reduced.

[0057] According to the present invention, preferably, in step S4, the industrial sodium carbonate product meets the requirements of GB / T210-2022 Class II superior products.

[0058] According to the present invention, preferably, in step S5:

[0059] The sodium bicarbonate in the conditioning solution is converted into sodium sulfate after the acidification treatment and generates acidified gas, and the acidified gas is sent to step S3 together with the calcination gas to mix with the residual wastewater and undergo carbonization reaction to enhance the carbonization effect;

[0060] The water vapor generated by the evaporation and crystallization treatment is used as part of the water mixed with the incineration residue to obtain residue waste water, thereby realizing the recycling of water resources in the process, and utilizing the waste heat of the water vapor to achieve heating and conditioning of the residue waste water, thereby reducing the process operation cost.

[0061] The industrial sodium sulfate product meets the requirements of GB / T6009-2014 Class I first-class products.

[0062] In the present invention, the ozone decolorization is to oxidize and decolorize the solution after acidification with ozone, which can oxidize Na2SO3 generated by absorbing SO2 in step S3 into Na2SO4, thereby improving the purity of the subsequent sodium sulfate product and meeting the requirements of Class I first-class products of GB / T6009-2014.

[0063] According to the present invention, preferably, in step S6, the denitration catalyst selected for the denitration purification treatment is a vanadium-based catalyst and / or an activated carbon-based catalyst.

[0064] According to the present invention, preferably, when the tempering gas temperature is higher than 250-270° C., a vanadium-based catalyst is selected.

[0065] According to the present invention, preferably, when the tempering gas temperature is lower than 190-210°C, an activated carbon-based catalyst is selected.

[0066] The beneficial effects of the technical solution of the present invention are as follows:

[0067] (1) The present invention realizes waste treatment in the catalytic cracking process, reduces the cost of treating process pollutants, and significantly improves the economic efficiency of the process;

[0068] (2) The method of the present invention recycles and utilizes the salt resources in the alkali residue wastewater to obtain high-quality industrial sodium carbonate and industrial sodium sulfate, avoiding the economic cost pressure caused by outsourcing hazardous waste, and enhancing the resource recovery capacity of the catalytic cracking process. Compared with the traditional process, it has higher economic and environmental advantages;

[0069] (3) The method of the present invention comprehensively utilizes the waste heat, SO2 and CO2 resources of the regenerated flue gas to achieve synergistic desulfurization of the regenerated flue gas, saves the regenerated flue gas desulfurization unit, reduces the land occupied by the pollutant treatment equipment, and reduces the use of heat energy and sulfuric acid in the process of treating pollutants such as alkali slag wastewater, thereby significantly reducing the cost of pollutant treatment.

[0070] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0072] Figure 1 A schematic diagram of a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery provided in Example 3 of the present invention is shown.

[0073] Figure 2 A schematic diagram of a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery provided in Example 1 of the present invention is shown.

[0074] Figure 3 A schematic diagram of a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery provided by the present invention is shown.

[0075] The following are the descriptions of the reference numerals:

[0076] 1. Alkali residue wastewater; 2. Regeneration flue gas; 3. Preheated alkaline residue wastewater; 4. Cooled regeneration flue gas; 5. Mixed flue gas; 6. Incineration flue gas; 7. Dust removal mixed flue gas; 8. Residue wastewater; 9. Sodium bicarbonate crystals; 10. Conditioning solution; 11. Conditioning gas; 12. Industrial sodium carbonate product; 13. Calcination gas; 14. Industrial sodium sulfate product; 15. Clean flue gas; 16. Heating conditioning gas; 17. Cooling incineration flue gas;

[0077] A. Heat exchanger; B. Incinerator; C. Tempering and carbonization unit; D. Calcination unit; E. First separation and recovery unit; F. Acidification unit; G. Ozone decolorization unit; H. Evaporation crystallization unit; I. Freeze crystallization unit; J. Second separation and recovery unit; K. Denitration unit; L. Dust removal unit; M. Denitration heat exchanger. DETAILED DESCRIPTION

[0078] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0079] Example 1

[0080] This embodiment provides a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, such as Figure 2 As shown, the system includes a heat exchanger A, an incinerator B, a dissolution unit, a tempering carbonization unit C, an industrial sodium carbonate recovery unit, an industrial sodium sulfate recovery unit and a denitrification unit K;

[0081] The heat exchanger A includes a wastewater inlet, a waste gas inlet, a heating wastewater outlet and a cooling waste gas outlet;

[0082] The incinerator B comprises an incinerator inlet, an incineration residue outlet and an incineration smoke outlet;

[0083] The conditioning carbonization unit C includes a residual wastewater inlet, a mixed flue gas inlet, a sodium bicarbonate crystal outlet, a conditioning solution outlet and a conditioning gas outlet;

[0084] The industrial sodium carbonate recovery unit comprises a calcination unit D and a first separation and recovery unit E connected in sequence; the first separation and recovery unit E is also connected to a calcination gas discharge pipeline and an industrial sodium carbonate product extraction pipeline;

[0085] The industrial sodium sulfate recovery unit comprises an acidification unit F, an ozone decolorization unit G, an evaporation crystallization unit H, a freezing crystallization unit I and a second separation and recovery unit J connected in sequence; the acidification unit F is also connected to an acidification gas discharge pipeline; the calcination gas discharge pipeline and the acidification gas discharge pipeline are connected to the mixed flue gas inlet together; the second separation and recovery unit J is also connected to an industrial sodium sulfate product extraction pipeline;

[0086] The temperature-raising wastewater outlet is connected to the inlet of the incinerator; the temperature-lowering waste gas outlet and the incineration flue gas outlet are both connected to the dust removal unit L, and the dust removal unit L is connected to the mixed flue gas inlet through a mixed flue gas pipeline; the incineration residue outlet is connected to the residue wastewater inlet through the dissolution unit; the sodium bicarbonate crystal outlet is connected to the calcination unit D; the conditioning solution outlet is connected to the acidification unit F; the conditioning gas outlet pipeline is connected to the denitration unit K. The denitration unit K is also connected to a clean flue gas discharge pipeline.

[0087] This embodiment also provides a method for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas, using the above system, wherein the catalytic cracking wastewater and waste gas are alkali residue wastewater and catalyst regeneration flue gas generated by a certain catalytic cracking process.

[0088] The water quality conditions of the alkali residue wastewater are as follows: temperature 21°C, TDS 76000mg / L, total alkalinity (calculated as CaCO3) 7622.8mg / L, NaOH 3.6%, Na2CO3 2.1%, Na2S (after conversion of sulfur-containing substances such as Na2S2O3 and Na2SO4) 4.6%, COD 39500mg / L, TOC 988mg / L, petroleum 36mg / L, other metal elements (Fe, Ca, Mg, etc.) 3.2mg / L;

[0089] The conditions of flue gas regeneration are as follows: flue gas temperature 360°C, particulate matter 16 mg / m 3 , SO2520mg / m 3 , CO213.2%, NO x 320 mg / m 3 .

[0090] The method comprises the following steps:

[0091] S1: exchanging heat between the alkali residue wastewater 1 and the regeneration flue gas 2 to obtain preheated alkali residue wastewater 3 (82° C.) and cooled regeneration flue gas 4 (152° C.);

[0092] S2: incinerating the preheated alkali slag wastewater 3 to obtain incineration residue and incineration flue gas 6; mixing the incineration flue gas 6 with the cooled regeneration flue gas 4 to obtain mixed flue gas, and performing dust removal treatment on the mixed flue gas to obtain dust-removed mixed flue gas 7;

[0093] in:

[0094] The conditions of incineration flue gas 6 are as follows: temperature 526℃, particulate matter 89mg / m 3 , SO2226mg / m 3 , CO211.6%, NO x 560mg / m 3 ;

[0095] The conditions of the dust removal mixed flue gas 7 are as follows: temperature 195°C, particulate matter 11 mg / m 3 , SO2386mg / m 3 , NO x 388mg / m 3 , CO2 content is 12.5%;

[0096] S3: mixing the incineration residue with water to obtain residue wastewater 8; mixing the residue wastewater 8 with the dust removal mixed flue gas 7 (the mixing ratio of the dust removal mixed flue gas 7 to the residue wastewater 8 is 5:1) and heating to perform tempering and carbonization reaction to obtain sodium bicarbonate crystals 9, a tempering solution 10 and a tempering gas 11;

[0097] in:

[0098] The conditions of the residual wastewater 8 are as follows: pH 9.4, Na2CO3 386 g / L, Na2SO4 407 g / L, metal elements (Fe, Ca, Mg, etc.) 4.2 mg / L, and the mass concentration of NaOH is 0.020 g / L;

[0099] The water quality conditions of the conditioning solution 10 include: temperature 45°C, pH 7.6, sodium bicarbonate 92g / L, sodium sulfate 442g / L, sodium sulfite 2.1g / L;

[0100] The conditions of the tempering gas 11 are as follows: temperature 142°C, particulate matter 8 mg / m 3 , SO246mg / m 3 , NO x 392mg / m 3 ;

[0101] S4: calcining and separating and recovering the sodium bicarbonate crystals 9 in sequence to obtain an industrial sodium carbonate product 12 (meeting the requirements of Class II superior products of GB / T 210-2022) and a calcined gas 13. The industrial sodium carbonate product 12 obtained has a total alkali content (calculated as Na2CO3, on a dry basis) of 99.3%, a total alkali content (calculated as Na2CO3, on a wet basis) of 98.0%, and a sodium chloride (calculated as NaCl, on a dry basis) of 0.33%;

[0102] S5: The sodium bicarbonate in the conditioning solution 10 is converted into sodium sulfate after being acidified with sulfuric acid and produces acidified gas CO2, and the acidified gas CO2 is sent to step S3 together with the calcining gas to be mixed with the residual wastewater and undergo a carbonization reaction;

[0103] Ozone is introduced into the acidified solution for decolorization, and Na2SO3 in the solution is oxidized to Na2SO4, so as to improve the purity of subsequent industrial sodium sulfate products. The water quality of the solution after ozone decolorization is as follows: temperature 38°C, pH 5.2, NaHCO3 <0.010g / L, Na2SO4 445g / L, Na2SO3 <0.010g / L;

[0104] The ozone decolorized solution is subjected to evaporation crystallization, freezing crystallization and separation and recovery treatment to obtain industrial sodium sulfate product 14, which meets the requirements of Class I superior products of GB / T6009-2014. The industrial sodium sulfate product 14 has a purity of 99.8%, a chloride (as Cl) of 0.003%, a whiteness (R457) of 96%, and a pH of 6.4;

[0105] S6: Use activated carbon-based catalyst and NH3 as reducing agent to denitrate the quenched gas. The conditions of the flue gas after denitrification are as follows: temperature 121℃, particulate matter 9mg / m 3 , SO222mg / m 3 , NO x 41mg / m 3 , achieving flue gas emission standards.

[0106] Example 2

[0107] This embodiment provides a method for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas, using the system described in Example 1, wherein the catalytic cracking wastewater and waste gas are alkali residue wastewater and catalyst regeneration flue gas generated by a certain catalytic cracking process.

[0108] The water quality conditions of the alkali residue wastewater are as follows: temperature 26°C, TDS 82000mg / L, total alkalinity (calculated as CaCO3) 5325.6mg / L, NaOH 4.2%, Na2CO3 2.3%, Na2S (after conversion of sulfur-containing substances such as Na2S2O3 and Na2SO4) 4.8%, COD 62350mg / L, TOC 1088mg / L, petroleum 21mg / L, other metal elements (Fe, Ca, Mg, etc.) 3.6mg / L;

[0109] The conditions of flue gas regeneration are as follows: flue gas temperature 380°C, particulate matter 21mg / m 3 , SO2585mg / m 3 , CO214.8%, NO x 346mg / m 3 .

[0110] The method comprises the following steps:

[0111] S1: exchanging heat between the alkali residue wastewater 1 and the regeneration flue gas 2 to obtain preheated alkali residue wastewater 3 (85° C.) and cooled regeneration flue gas 4 (175° C.);

[0112] S2: incinerating the preheated alkali slag wastewater 3 to obtain incineration residue and incineration flue gas 6; mixing the incineration flue gas 6 with the cooled regeneration flue gas 4 to obtain mixed flue gas, and performing dust removal treatment on the mixed flue gas to obtain dust-removed mixed flue gas 7;

[0113] in:

[0114] The conditions for burning flue gas 6 are as follows: temperature 620°C, particulate matter 96 mg / m 3 , SO2207mg / m 3 , CO2 10.6%, NO x 496mg / m 3 ;

[0115] The conditions of the dust removal mixed flue gas 7 are as follows: temperature 182°C, particulate matter 12mg / m 3 , SO2402mg / m 3 , NO x 378mg / m 3 , CO2 content is 12.8%;

[0116] S3: mixing the incineration residue with water to obtain residue wastewater 8; mixing the residue wastewater 8 with the dust removal mixed flue gas 7 (the mixing ratio of the dust removal mixed flue gas 7 to the residue wastewater 8 is 7.5:1) and heating to perform tempering and carbonization reaction to obtain sodium bicarbonate crystals 9, a tempering solution 10 and a tempering gas 11;

[0117] in:

[0118] The conditions of the residual wastewater 8 are as follows: pH 9.8, Na2CO3 327 g / L, Na2SO4 422 g / L, metal elements (Fe, Ca, Mg, etc.) 4.3 mg / L, and the mass concentration of NaOH is 0.0010 g / L;

[0119] The water quality conditions of the conditioning solution 10 include: temperature 48°C, pH 7.8, sodium bicarbonate 95g / L, sodium sulfate 456g / L, sodium sulfite 2.6g / L;

[0120] The conditions of the tempering gas 11 are as follows: temperature 151°C, particulate matter 9 mg / m 3 , SO242mg / m 3 , NO x 382mg / m 3 ;

[0121] S4: calcining and separating and recovering the sodium bicarbonate crystals 9 in sequence to obtain an industrial sodium carbonate product 12 (meeting the requirements of Class II superior products of GB / T 210-2022) and a calcined gas 13. The industrial sodium carbonate product 12 obtained has a total alkali content (calculated as Na2CO3, on a dry basis) of 99.2%, a total alkali content (calculated as Na2CO3, on a wet basis) of 98.0%, and a sodium chloride (calculated as NaCl, on a dry basis) of 0.37%;

[0122] S5: The sodium bicarbonate in the conditioning solution 10 is converted into sodium sulfate after being acidified with sulfuric acid and produces acidified gas CO2, and the acidified gas CO2 is sent to step S3 together with the calcining gas to be mixed with the residual wastewater and undergo a carbonization reaction;

[0123] After the acidification treatment, ozone is introduced into the solution for decolorization, and Na2SO3 in the solution is oxidized to Na2SO4, so as to improve the purity of the subsequent industrial sodium sulfate product. The water quality of the solution after ozone decolorization is as follows: temperature 40°C, pH 5.3, NaHCO3 <0.010g / L, Na2SO4 459g / L, Na2SO3 <0.010g / L;

[0124] The ozone decolorized solution is subjected to evaporation crystallization, freezing crystallization and separation and recovery treatment to obtain industrial sodium sulfate product 14, which meets the requirements of Class I superior products of GB / T6009-2014. The industrial sodium sulfate product 14 has a purity of 99.8%, a chloride (as Cl) of 0.008%, a whiteness (R457) of 95%, and a pH of 6.5;

[0125] S6: Use activated carbon-based catalyst and NH3 as reducing agent to denitrate the quenched gas. The conditions of the flue gas after denitrification are as follows: temperature 126℃, particulate matter 9mg / m 3 , SO212mg / m 3 , NO x 36 mg / m 3 , achieving flue gas emission standards.

[0126] Example 3

[0127] This embodiment provides a system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, such as Figure 1 As shown, the system differs from Example 1 only in that no dust removal unit is included, and the cooling exhaust gas outlet and the incineration flue gas outlet are directly connected to the mixed flue gas inlet.

[0128] This embodiment provides a method for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas, using the above-mentioned system, wherein the catalytic cracking wastewater and waste gas are alkali residue wastewater and catalyst regeneration flue gas generated by a certain catalytic cracking process.

[0129] The water quality conditions of the alkali residue wastewater are as follows: temperature 27°C, TDS 52000mg / L, total alkalinity (calculated as CaCO3) 452.5mg / L, NaOH 3.9%, Na2CO3 2.1%, Na2S (after conversion of sulfur-containing substances such as Na2S2O3 and Na2SO4) 4.4%, COD 56620mg / L, TOC 961mg / L, petroleum 56mg / L, other metal elements (Fe, Ca, Mg, etc.) 3.3mg / L;

[0130] The conditions of flue gas regeneration are as follows: flue gas temperature 370°C, particulate matter 10mg / m 3 , SO2566mg / m 3 , CO2 10.7%, NO x 386mg / m 3 .

[0131] The method comprises the following steps:

[0132] S1: exchanging heat between the alkali residue wastewater 1 and the regeneration flue gas 2 to obtain preheated alkali residue wastewater 3 (82° C.) and cooled regeneration flue gas 4 (178° C.);

[0133] S2: incinerating the preheated alkali slag wastewater 3 to obtain incineration residue and incineration flue gas 6; mixing the incineration flue gas 6 with the cooled regeneration flue gas 4 to obtain mixed flue gas 5;

[0134] in:

[0135] The conditions of incineration flue gas 6 are as follows: temperature 590°C, particulate matter 33 mg / m 3 , SO2369mg / m 3 , CO213.6%, NO x 622mg / m 3 ;

[0136] The conditions of mixed flue gas 5 are as follows: temperature 362°C, particulate matter 19 mg / m 3 , SO2446mg / m 3 , NO x 428mg / m 3 , CO2 content is 12.6%;

[0137] S3: mixing the incineration residue with water to obtain residue waste water 8; mixing the residue waste water 8 with the mixed flue gas 5 (the mixing ratio of the mixed flue gas 5 to the residue waste water 8 is 3.5:1) and heating to perform tempering and carbonization reaction to obtain sodium bicarbonate crystals 9, a tempering solution 10 and a tempering gas 11;

[0138] in:

[0139] The conditions of the residual wastewater 8 are as follows: pH 9.5, Na2CO3 297 g / L, Na2SO4 395 g / L, metal elements (Fe, Ca, Mg, etc.) 2.6 mg / L, and the mass concentration of NaOH is 0.0010 g / L;

[0140] The water quality conditions of the conditioning solution 10 include: temperature 46°C, pH 7.7, sodium bicarbonate 83 g / L, sodium sulfate 401 g / L, sodium sulfite 2.8 g / L;

[0141] The conditions of the tempering gas 11 are as follows: temperature 308°C, particulate matter 12 mg / m 3 , SO245mg / m 3 , NO x 407 mg / m 3 ;

[0142] S4: calcining and separating and recovering the sodium bicarbonate crystals 9 in sequence to obtain an industrial sodium carbonate product 12 (meeting the requirements of Class II superior products of GB / T 210-2022) and a calcined gas 13. The industrial sodium carbonate product 12 obtained has a total alkali content (calculated as Na2CO3, on a dry basis) of 99.2%, a total alkali content (calculated as Na2CO3, on a wet basis) of 98.1%, and a sodium chloride (calculated as NaCl, on a dry basis) of 0.31%;

[0143] S5: The sodium bicarbonate in the conditioning solution 10 is converted into sodium sulfate after being acidified with sulfuric acid and produces acidified gas CO2, and the acidified gas CO2 is sent to step S3 together with the calcining gas to be mixed with the residual wastewater and undergo a carbonization reaction;

[0144] The solution after acidification was decolorized by introducing ozone, and Na2SO3 in the solution was oxidized to Na2SO4, so as to improve the purity of subsequent industrial sodium sulfate products. The water quality of the solution after ozone decolorization was as follows: temperature 41°C, pH 5.0, NaHCO3 <0.010g / L, Na2SO4 408g / L, Na2SO3 <0.010g / L;

[0145] The ozone decolorized solution is subjected to evaporation crystallization, freezing crystallization and separation and recovery treatment to obtain industrial sodium sulfate product 14, which meets the requirements of Class I superior products of GB / T6009-2014. The industrial sodium sulfate product 14 has a purity of 99.9%, a chloride (as Cl) of 0.006%, a whiteness (R457) of 98%, and a pH of 6.2;

[0146] S6: Vanadium-based catalysts are used to denitrate the quenched gas using NH3 as a reducing agent. The conditions of the flue gas after denitration are as follows: temperature 292°C, particulate matter 10mg / m 3 , SO242mg / m 3 , NO x 31mg / m 3 , achieving flue gas emission standards.

[0147] Embodiment 4-8

[0148] Compared with Example 1, Example 4-8 has different temperatures and proportions of the cooled regeneration flue gas by adjusting the heat exchange efficiency of step S1, thereby obtaining different temperatures of the dust removal mixed flue gas. Apart from this, other operations are the same as Example 1. The changes in the total alkalinity of the sodium carbonate products obtained in Example 4-8 and Example 1 are shown in Table 1 below.

[0149] Table 1

[0150]

[0151]

[0152] It can be seen from the results in Table 1 that when the temperature of the dust removal mixed flue gas is 100-200°C, the sodium carbonate product can maintain a total alkali content (calculated as Na2CO3, on a dry basis) ≥ 99.2%, and a total alkali content (calculated as Na2CO3, on a wet basis) ≥ 97.9%, which meets the requirements of Class II superior sodium carbonate products specified in GB / T 210-2022.

[0153] However, when the temperature of the dust removal mixed flue gas exceeds 200°C (Example 5), the temperature of the tempering solution is 50°C. At this time, the solubility of sodium bicarbonate produced in the carbonization process in the tempering solution increases, while the solubility of sodium chloride remains basically unchanged, resulting in an increase in the proportion of sodium chloride impurities in the final product, and sodium carbonate is difficult to meet the requirements of Class II superior sodium carbonate specified in GB / T210-2022.

[0154] When the temperature of the dust removal mixed flue gas is lower than 100°C, the temperature of the tempering solution is lower than 40°C, the effect of the tempering process becomes worse, and the solubility of sodium sulfate decreases significantly. The impurity content of sodium sulfate in the final sodium carbonate product increases, which makes it difficult to meet the requirements of Class II superior sodium carbonate products specified in GB / T210-2022.

[0155] Examples 9-13, Comparative Example 1

[0156] Compared with Example 1, Examples 9-13 and Comparative Example 1 differ only in the mixing ratio of the dust removal mixed flue gas and the residual wastewater. Other than that, the other operations are the same as those of Example 1. The changes in the total alkalinity of the sodium carbonate products obtained in Examples 9-13, Comparative Example 1 and Example 1 are shown in Table 2 below.

[0157] Table 2

[0158]

[0159]

[0160] The results in Table 2 show that when the ratio of dust removal mixed flue gas to residual wastewater is between 2.5:1 and 12.5:1, the heat exchange effect is better, the temperature of the quenching solution is maintained between 40 and 50 °C, the quality of the sodium carbonate product is maintained at the standard of Class II superior sodium carbonate specified in GB / T 210-2022, and the SO2 content of the quenching gas is 50 mg / m 3 Below, the SO2 emission limit is met.

[0161] When the ratio of dust removal mixed flue gas is too large (the ratio of dust removal mixed flue gas to residual wastewater is 13.7:1), the SO2 content of the tempering gas exceeds the standard (>50mg / m 3 ), and the temperature of the conditioning wastewater exceeds 50°C, the quality of the sodium carbonate product is reduced, and it does not meet the requirements of Class II superior products of sodium carbonate specified in GB / T210-2022.

[0162] When the dust removal mixed flue gas is not used, the solubility of the tempering solution is too low and the quality of the sodium carbonate product is significantly reduced.

[0163] Examples 14-26

[0164] Compared with Example 1, Examples 14-26 differ only in the SO2 content in the dust removal mixed flue gas. Other than that, the other operations are the same as those of Example 1 (wherein, the method for regulating the SO2 content in the dust removal mixed flue gas includes: before the residual wastewater is mixed with the dust removal mixed flue gas, adding a SO2 content regulating unit to regulate the SO2 in the dust removal mixed flue gas). The changes in the total alkalinity of the sodium carbonate products obtained in Examples 14-26 and Example 1 and the SO2 content of the tempering gas are shown in Table 3 below.

[0165] Table 3

[0166]

[0167] The results in Table 3 show that by adjusting the SO2 content in the dust removal mixed flue gas, the pH of the conditioning solution will be affected, thereby affecting the efficiency of the carbonization process. 3 When the pH value of the tempering solution is within the specified range, the pH value of the tempering solution is 8.0 or below, the carbonization efficiency is guaranteed, and the obtained sodium carbonate product meets the requirements of Class II superior sodium carbonate specified in GB / T 210-2022.

[0168] When the SO2 content in the dust removal mixed flue gas is 100mg / m 3 When the pH value is below 8.0, the pH value of the tempering solution is higher than 8.0, and the carbonization efficiency is reduced, resulting in the sodium carbonate product being unable to meet the requirements of Class II superior sodium carbonate specified in GB / T 210-2022.

[0169] When the SO2 content in the dust removal mixed flue gas is 1200mg / m 3 When the SO2 content of the tempering gas reaches 50mg / m 3 , unable to meet the SO2 emission standards.

[0170] Examples 27-34

[0171] Compared with Example 1, Examples 27-34 differ only in the CO2 content in the dust removal mixed flue gas. Other than that, the other operations are the same as those of Example 1 (wherein, the method for regulating the CO2 content in the dust removal mixed flue gas includes: before the residual wastewater is mixed with the dust removal mixed flue gas, adding a CO2 content regulating unit to regulate the CO2 in the dust removal mixed flue gas). The changes in the total alkalinity of the sodium carbonate products obtained in Examples 27-34 and Example 1 and the CO2 content of the tempering gas are shown in Table 4 below.

[0172] Table 4

[0173]

[0174] It can be seen from the results in Table 4 that when the CO2 content in the dust removal mixed flue gas is 8-16%, the carbonization effect is excellent, and the purity of the sodium carbonate product meets the requirements of Class II superior sodium carbonate specified in GB / T 210-2022.

[0175] When the CO2 content in the dust removal mixed flue gas is higher than 16%, the CO2 content in the tempering gas exceeds 4%, the CO2 escape amount increases, and the low-carbon and environmental protection performance of the process decreases.

[0176] When the CO2 content in the dust removal mixed flue gas is lower than 8%, the CO2 content in the carbonization process is insufficient, the carbonization effect decreases, and the quality of the sodium carbonate product does not meet the requirements of Class II superior sodium carbonate products specified in GB / T 210-2022.

[0177] When the dust removal mixed flue gas does not contain CO2, the carbonization process is difficult to occur and the product quality deteriorates significantly.

[0178] Comparative Example 2

[0179] The difference between this comparative example and Example 3 is that there is no ozone decolorization step in this comparative example.

[0180] In Example 3, an ozone decolorization step is adopted, and the purity of the obtained industrial sodium sulfate product 14 reaches 99.9%, and the whiteness (R457) reaches 98%, which meets the requirements of GB / T6009-2014 Class I superior products.

[0181] This comparative example does not use the ozone decolorization step, and the purity of the obtained sodium sulfate product is 99.4%, and the whiteness (R457) is 86%, which does not meet the requirements of GB / T6009-2014 Class I superior products, and only meets the requirements of GB / T6009-2014 Class I first-class products, and the product quality is reduced.

[0182] It can be seen from this that the ozone decolorization process of the present invention can not only oxidize the flue gas desulfurization impurity Na2SO3 into Na2SO4, thereby improving the purity of the sodium sulfate product and also having a certain effect on improving the product quantity, but also can improve the whiteness of the ammonium sulfate product through the ozone bleaching effect, thereby obtaining a high-quality sodium sulfate product.

[0183] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A system for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, characterized in that: The system includes a heat exchanger, an incinerator, a dissolution unit, a tempering carbonization unit, an industrial sodium carbonate recovery unit, an industrial sodium sulfate recovery unit and a denitration unit; The heat exchanger includes a wastewater inlet, a waste gas inlet, a temperature-raising wastewater outlet, and a temperature-lowering waste gas outlet; The incinerator comprises an incinerator inlet, an incineration residue outlet and an incineration smoke outlet; The conditioning carbonization unit comprises a residual wastewater inlet, a mixed flue gas inlet, a sodium bicarbonate crystal outlet, a conditioning solution outlet and a conditioning gas outlet; The industrial sodium carbonate recovery unit comprises a calcination unit and a first separation and recovery unit connected in sequence; The industrial sodium sulfate recovery unit comprises an acidification unit, an ozone decolorization unit, an evaporation crystallization unit, a freezing crystallization unit and a second separation recovery unit connected in sequence; The heated wastewater outlet is connected to the inlet of the incinerator; the cooled waste gas outlet and the incineration flue gas outlet are both connected to the mixed flue gas inlet; the incineration residue outlet is connected to the residue wastewater inlet through the dissolution unit; the sodium bicarbonate crystal outlet is connected to the calcination unit; the tempering solution outlet is connected to the acidification unit; and the tempering gas outlet pipeline is connected to the denitration unit.

2. The system for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas according to claim 1, wherein: The system further comprises a denitration heat exchanger, wherein the denitration heat exchanger comprises a heat source inlet, a cold source inlet, a temperature-increasing material outlet and a temperature-reducing material outlet; The incineration smoke outlet is connected to the heat source inlet; the cooling material outlet is connected to the mixed smoke inlet; The tempering gas outlet is connected to the cold source inlet; the heating material outlet is connected to the denitration unit.

3. The system for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas according to claim 1 or 2, wherein: The system also includes a dust removal unit; The cooling exhaust gas outlet and the incineration flue gas outlet are both connected to the dust removal unit, and the dust removal unit is connected to the mixed flue gas inlet through a mixed flue gas pipeline; or, When a denitration heat exchanger is provided, the cooling exhaust gas outlet and the cooling material outlet are both connected to the dust removal unit, and the dust removal unit is connected to the mixed flue gas inlet via a mixed flue gas pipeline.

4. The system for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas according to claim 1, wherein: The first separation and recovery unit is also connected to a calcined gas discharge pipeline and an industrial sodium carbonate product production pipeline; The acidification unit is also connected to an acidification gas discharge pipeline; The calcination gas discharge pipeline and the acidification gas discharge pipeline are connected to the mixed flue gas inlet; The second separation and recovery unit is also connected to an industrial sodium sulfate product extraction pipeline; The destocking unit is also connected to a clean flue gas discharge pipeline.

5. A method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery, characterized in that: The method adopts the system according to any one of claims 1 to 4, comprising the following steps: S1: exchanging heat between the alkali residue wastewater and the regeneration flue gas to obtain preheated alkali residue wastewater and cooled regeneration flue gas; S2: incinerating the preheated alkali slag wastewater to obtain incineration residue and incineration flue gas; mixing the incineration flue gas with the cooled regeneration flue gas to obtain mixed flue gas; S3: mixing the incineration residue with water to obtain residue wastewater; mixing the residue wastewater with the mixed flue gas and heating them to perform tempering and carbonization reactions to obtain sodium bicarbonate crystals, a tempering solution and a tempering gas; S4: calcining and separating and recovering the sodium bicarbonate crystals in sequence to obtain an industrial sodium carbonate product and calcination gas; S5: sequentially subjecting the conditioned solution to acidification, ozone decolorization, evaporation crystallization, freezing crystallization, and separation and recovery treatment to obtain an industrial sodium sulfate product; S6: Denitrification and purification are performed on the tempered gas to achieve emission standards.

6. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S1: The regeneration flue gas is waste flue gas from a heating boiler and / or regeneration flue gas from a catalytic cracking catalyst, and the components of the regeneration flue gas include SO2, CO2 and NO x ; The temperature of the regenerated flue gas is 300-500°C; The temperature of the preheated alkali residue wastewater is 60-90°C; The temperature of the cooled regeneration flue gas is 100-180°C.

7. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S2: The temperature of the incineration flue gas is 450-650°C; The incineration flue gas is first heat exchanged with the tempering gas of step S6 to obtain cooled incineration flue gas and heated tempering gas; the cooled incineration flue gas is then mixed with the cooled regenerated flue gas to obtain mixed flue gas; the heated tempering gas is subjected to denitration purification treatment and is discharged in compliance with emission standards.

8. The method for coordinated treatment and resource recovery of catalytic cracking wastewater and waste gas according to claim 5 or 7, wherein: In step S2: The particle concentration of the mixed flue gas is less than 15 mg / m 3 ; Alternatively, the mixed flue gas is subjected to dust removal treatment to obtain dust-removed mixed flue gas, and the residual wastewater is mixed with the dust-removed mixed flue gas and subjected to tempering and carbonization reactions to obtain sodium bicarbonate crystals, a tempering solution and a tempering gas.

9. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 8, wherein: The SO2 content of the mixed flue gas and the dust-removed mixed flue gas is independently 95-1205 mg / m 3 ; The CO2 content of the mixed flue gas and the dust-removed mixed flue gas is independently 7.5-16.5%; The temperature of the mixed flue gas is 250-450°C, and the temperature of the dust removal mixed flue gas is 95-205°C; The volume mixing ratio of the mixed flue gas to the residual wastewater is (1-6.5):1; the volume mixing ratio of the dust removal mixed flue gas to the residual wastewater is (2-13):

1.

10. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S3: The water mixed with the incineration residue is distilled water; The water quality conditions of the residual wastewater include: pH 7.8-12.2, mass concentration of Na2SO4 350-470g / L, mass concentration of Na2CO3 300-460g / L, mass concentration of metal elements 0.001-0.010g / L, mass concentration of NaOH 0-0.050g / L; The temperature of the carbonization reaction is 30-50°C.

11. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S3: The water quality conditions of the conditioning solution include: pH 7.5-8.5, mass concentration of sodium bicarbonate 80-100 g / L, mass concentration of sodium sulfate 360-480 g / L and mass concentration of sodium sulfite 1-5 g / L; The SO2 content in the tempering gas is 30-50 mg / m 3 .

12. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S4, the industrial sodium carbonate product meets the requirements of GB / T 210-2022 Class II superior products.

13. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S5: The sodium bicarbonate in the tempering solution is converted into sodium sulfate after the acidification treatment and generates acidified gas, and the acidified gas is sent to step S3 together with the calcination gas to mix with the residual wastewater and undergo a carbonization reaction; using the water vapor generated by the evaporation and crystallization process as part of the water mixed with the incineration residue to obtain residue wastewater; The industrial sodium sulfate product meets the requirements of GB / T6009-2014 Class I first-class products.

14. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 5, wherein: In step S6, the denitration catalyst selected for the denitration purification treatment is a vanadium-based catalyst and / or an activated carbon-based catalyst.

15. The method for coordinated treatment of catalytic cracking wastewater and waste gas and resource recovery according to claim 14, wherein: When the tempering gas temperature is higher than 250-270°C, a vanadium-based catalyst is selected; When the tempering gas temperature is lower than 190-210°C, an activated carbon-based catalyst is selected.

Images