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CN-122006470-A - Process for degrading VOCs in sulfur-containing waste gas

CN122006470ACN 122006470 ACN122006470 ACN 122006470ACN-122006470-A

Abstract

The invention belongs to the technical field of metal catalyst preparation, and particularly relates to a process for degrading VOCs in sulfur-containing waste gas. The process comprises the steps of (1) preparing a surfactant solution and a catalyst carrier, (2) blending a phthalocyanine ring ligand, ZIF-L, central metal salt, a reaction auxiliary agent and the surfactant solution, adding the catalyst carrier for primary impregnation, continuously adding heteropolyacid and vanadium salt for secondary impregnation, (3) blending the catalyst carrier subjected to secondary impregnation with a nitrogen source, carrying out fusion reaction, (4) heating, introducing air for primary calcination, then carrying out secondary calcination under an inert atmosphere, and cooling to obtain the VOCs catalyst, (5) loading the VOCs catalyst into a reactor, heating, introducing sulfur-containing waste gas, and degrading the VOCs in the sulfur-containing waste gas. The invention improves the VOCs degradation efficiency and sulfur dioxide poisoning resistance of the existing metal catalyst by preparing the multi-metal catalyst.

Inventors

  • LI JIE

Assignees

  • 淄博职业技术大学

Dates

Publication Date
20260512
Application Date
20260408

Claims (10)

  1. 1. A process for degrading VOCs in sulfur-containing flue gas, comprising the steps of: (1) Preparing a surfactant solution and a catalyst carrier; (2) Blending the phthalocyanine ring ligand, ZIF-L, central metal salt, reaction auxiliary agent and surfactant solution, adding a catalyst carrier into the mixture for primary impregnation; (3) Blending the catalyst carrier subjected to secondary impregnation with a nitrogen source, and carrying out melt reaction; (4) Continuously heating, introducing air to perform primary calcination, performing secondary calcination under inert atmosphere, and cooling to obtain the VOCs catalyst; (5) And loading the VOCs catalyst into a reactor, heating, and introducing sulfur-containing waste gas to degrade VOCs in the sulfur-containing waste gas.
  2. 2. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in step (1), the surfactant solution is prepared from surfactant, micelle stabilizer and water according to the mass ratio of (85-100): (35-50): 2500, the surfactant is 1-hexadecyl-3-methylimidazolium bromide or didecyl dimethyl ammonium bromide, and the micelle stabilizer is potassium bromide or sodium bromide.
  3. 3. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in the step (1), the catalyst carrier is prepared by sequentially pretreating Fe-Cr-Al honeycomb metal, heating, impregnating carrier slurry, drying and roasting, wherein the pretreatment is to add Fe-Cr-Al honeycomb metal into toluene for cleaning, then adding the mixture into 1.5-3 mol/L nitric acid aqueous solution for cleaning, finally washing with clear water and drying, the heating temperature is 880-900 ℃, the heating time is 8-10 h, the carrier slurry is prepared by mixing gamma-Al 2 O 3 powder, pseudo-boehmite and water, the pH value is regulated to be 4-4.5, and stirring is continued for 7-9 h, wherein the carrier slurry is prepared by 25-30wt% gamma-Al 2 O 3 , 5-6wt% pseudo-boehmite and the balance water, the mass ratio of the Fe-Cr-honeycomb metal and the carrier slurry is 650 (1500-1800 ℃), the roasting temperature is 550-570 ℃ and the roasting time is 1-2 h.
  4. 4. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in step (2), the phthalocyanine ring ligand is 4-sulfonated ammonium phthalate, the central metal salt is cobalt chloride hexahydrate, the reaction auxiliary agent is ammonium tungstate, and the mass ratio of the phthalocyanine ring ligand, ZIF-L, the central metal salt, the reaction auxiliary agent and the surfactant solution is (250-275): 60 (40-50): 2620-2650.
  5. 5. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in the step (2), the heteropolyacid is 12-molybdenum phosphoric acid, the vanadium salt is ammonium metavanadate, the mass ratio of the catalyst carrier, the heteropolyacid, the vanadium salt and the surfactant solution is 600 (90-120): (72-90): (2620-2650), the primary soaking time is 30-40 min, and the secondary soaking time is 18-25 min.
  6. 6. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in the step (3), the nitrogen source is urea, the mass ratio of urea to catalyst carrier is (750-850): 600, the melting reaction temperature is 190-200 ℃, and the melting reaction time is 2.5-3.5 h.
  7. 7. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in step (4), the temperature rising rate is 10.5-13.5 ℃ per minute, and the air introducing rate is 9700-12000 mL per minute.
  8. 8. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in the step (4), the primary calcination temperature is 550-560 ℃, the primary calcination time is 3-4 hours, the secondary calcination temperature is 550-560 ℃, the secondary calcination time is 0.5-1 hour, and the cooling rate is 6-8 ℃ per minute.
  9. 9. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in step (5), the temperature of the reactor is 260-280 ℃, and the volume space velocity of the sulfur-containing waste gas is 13000-18000 h -1 .
  10. 10. The process for degrading VOCs in sulfur-containing waste gas according to claim 1, wherein in the step (5), the sulfur-containing waste gas contains VOCs, the VOCs comprise non-methane total hydrocarbons and non-hydrocarbon VOCs, the non-hydrocarbon VOCs comprise formaldehyde, acetaldehyde and succinaldehyde, the content of the non-methane total hydrocarbons is 200-460 mg/m 3 , the total content of the non-hydrocarbon VOCs is 50-460 mg/m 3 , and the content of sulfur dioxide is 50-780 mg/m 3 .

Description

Process for degrading VOCs in sulfur-containing waste gas Technical Field The invention belongs to the technical field of metal catalyst preparation, and particularly relates to a process for degrading VOCs in sulfur-containing waste gas. Background Volatile organic compounds, VOCs for short, are widely used in petroleum processing, printing, coating, building material production and other fields, and are various in variety, PM2.5 and photochemical smog can be formed in the atmosphere to pollute the environment, and in addition, the volatile organic compounds can volatilize at room temperature to cause harm to human health. The current large-scale control method is to install metal catalysts in an exhaust emission system, and degrade VOCs into harmless carbon dioxide, nitrogen, water and the like in a catalytic oxidation mode. In order to cope with the characteristics of high flux and low residence time of the waste gas, the treatment efficiency of VOCs in unit volume of the catalyst is insufficient, for example, in petroleum refining and petrochemical production processes, the waste gas components are complex, including non-methane total hydrocarbons, aldehydes and the like, and volatile sulfides such as sulfur dioxide are sometimes contained, so that the metal catalyst is easy to deactivate. Chinese patent CN108295866a discloses a nano flower spinel CoMn 2O4 catalyst for catalytic oxidation of VOCs, wherein the catalyst component is single crystal phase CoMn 2O4, and is prepared from manganese acetate, cobalt nitrate and oxalic acid by sol-gel method. The patent focuses on the low-temperature activity, oxygen flow property and according to the original text, the nano flower spinel component is single crystal phase CoMn 2O4, but the sulfur dioxide poisoning resistance of the nano flower spinel component is limited, and the patent catalyst does not relate to other measures for resisting sulfur dioxide poisoning. Chinese patent CN119869598A discloses a VOCs catalyst and a preparation method thereof, wherein the VOCs catalyst comprises a modified ZSM-5 zeolite molecular sieve and loaded active metal and/or active metal oxide, the preparation method comprises the steps of adding an H-ZSM-5 zeolite molecular sieve into an organic alkali solution for hydrothermal reaction after roasting, washing, suction filtering, drying and roasting after the reaction is finished to obtain alkali-treated ZSM-5, and then adding the alkali-treated ZSM-5 into an active metal/metal oxide corresponding acid/salt solution, removing water and roasting to obtain the VOCs catalyst. The patent has the steps of multiple calcination and hydrothermal treatment, has complex operation and is not beneficial to industrial production. Disclosure of Invention The invention aims to provide a process for degrading VOCs in sulfur-containing waste gas, so as to improve the VOCs degradation efficiency and sulfur dioxide poisoning resistance of the existing metal catalyst. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the invention discloses a process for degrading VOCs in sulfur-containing waste gas, which comprises the following steps: (1) Preparing a surfactant solution and a catalyst carrier; (2) Blending the phthalocyanine ring ligand, ZIF-L, central metal salt, reaction auxiliary agent and surfactant solution, adding a catalyst carrier into the mixture for primary impregnation; (3) Blending the catalyst carrier subjected to secondary impregnation with a nitrogen source, and carrying out melt reaction; (4) Continuously heating, introducing air to perform primary calcination, and then performing secondary calcination and cooling in an inert atmosphere to obtain the VOCs catalyst; (5) And loading the VOCs catalyst into a reactor, heating, and introducing sulfur-containing waste gas to degrade VOCs in the sulfur-containing waste gas. Wherein: In the step (1), the surfactant solution is prepared from surfactant, micelle stabilizer and water according to the mass ratio of (85-100): 35-50): 2500, wherein the surfactant is 1-hexadecyl-3-methylimidazole bromide or bisdecanyl dimethyl ammonium bromide, and the micelle stabilizer is potassium bromide or sodium bromide. In the step (1), preparing a catalyst carrier comprises the following steps of sequentially preprocessing Fe-Cr-Al honeycomb metal, heating, impregnating carrier slurry, drying and roasting to prepare the catalyst carrier; The pretreatment comprises the steps of adding Fe-Cr-Al honeycomb metal into toluene for cleaning, adding the mixture into 1.5-3 mol/L nitric acid aqueous solution for cleaning, finally washing with clear water and drying, wherein the heating temperature is 880-900 ℃, the heating time is 8-10 hours, carrier slurry is prepared by mixing gamma-Al 2O3 powder, pseudo-boehmite and water uniformly, adjusting pH value to be 4-4.5 and continuously stirring for 7-9 hours, wherein the carrier slurry is prepared by 25-30wt% gamma-