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CN-121988310-A - Hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, and preparation process and application thereof

CN121988310ACN 121988310 ACN121988310 ACN 121988310ACN-121988310-A

Abstract

The invention relates to a hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, a preparation process and application thereof, the process prepares the carbon disulfide hydrolysis catalyst with low-temperature activity and good hydrothermal stability through a carrier modification and surface modification technology. The hydrolysis catalyst has stronger deoxidization performance by introducing molybdenum element and cerium oxide for modifying the carrier, and inhibits aluminum hydroxyl hydration reaction by surface silicon hydroxyl modification, so that the hydrothermal stability of the active alumina carrier is improved, the active alumina carrier can maintain the catalytic combustion capability for trace oxygen for a long time, and can maintain stable structure for a long time under the water vapor atmosphere. Compared with the prior art, the invention has the advantages of stable structure, sulfate poisoning resistance, high content of carbon dioxide and oxygen tolerance and the like.

Inventors

  • XU HUASHENG
  • YU JINPENG
  • HE QIUPING
  • ZHANG JIA
  • HU JIE
  • LI CHUNCHENG
  • ZHOU YONGXIAN

Assignees

  • 上海绿强新材料有限公司

Dates

Publication Date
20260508
Application Date
20251225

Claims (9)

  1. 1. The preparation process of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas is characterized by comprising the following steps of: (1) Mixing pseudo-boehmite, nano cerium oxide and ammonium molybdate, dispersing in an acetic acid aqueous solution to prepare a suspension, adding silica gel micropowder into the suspension, and carrying out spray granulation and roasting by a spray dryer after grinding treatment by using a colloid mill to prepare the porous alumina composite carrier; (2) Preparing an ethanol water solution of tetraethoxysilane with certain silicon content, adding a dispersing agent to obtain an impregnating solution, adding the porous alumina composite carrier obtained in the step (1) into the impregnating solution according to an equal volume impregnating method, dispersing at a high speed, then impregnating, filtering, drying, and reducing in hydrogen to obtain a silicon modified porous alumina composite carrier; (3) Immersing the silicon modified porous alumina composite carrier obtained in the step (2) into a first auxiliary agent solution, immersing, filtering and drying to obtain a component A; (4) Immersing the magnesium aluminum hydrotalcite powder body into a second auxiliary agent solution, immersing, filtering and drying to obtain a component B; (5) And uniformly mixing the prepared component A, component B and the binder, extruding, forming and drying to obtain the hydrolysis catalyst.
  2. 2. The preparation process of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, which is characterized in that in the step (1), the mass ratio of pseudo-boehmite, nano-cerium oxide and ammonium molybdate is (90-110): 0.5-2): 30-40; the addition amount of the silica gel micro powder is 1-3wt% of the total mass of the pseudo-boehmite, the nano cerium oxide and the ammonium molybdate; The solid-to-liquid ratio of the pseudo-boehmite, the nano-cerium oxide and the ammonium molybdate to the acetic acid aqueous solution is 10-30wt%, and the acetic acid concentration in the acetic acid aqueous solution is 1-3wt%; The inlet gas temperature of the spray dryer is 200-250 ℃, the outlet gas temperature is 120-150 ℃, and the process conditions of the roasting process are that the roasting temperature is 500-600 ℃ and the roasting time is 2-4 h.
  3. 3. The process for preparing the hydrolysis catalyst for deoxidizing and removing organic sulfur in gas according to claim 1, wherein in the step (2), the dispersing agent is sodium polyacrylate; The silicon content of the impregnating solution is 3-7wt% calculated by SiO 2 , and the impregnating solution contains 0.5-2wt% of sodium polyacrylate; The soaking time is 1-2 h, the soaking temperature is 40-60 ℃, the drying temperature is 100-140 ℃, the time is 1-3 h, the hydrogen reduction temperature is 400-550 ℃ and the time is 6-12 h.
  4. 4. The preparation process of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, which is characterized in that in the step (3), the first auxiliary agent is one or more of potassium carbonate, potassium hydroxide, cesium carbonate or cesium hydroxide, the impregnation time is 10-30 min, the drying temperature is 180-220 ℃ and the time is 1-3 h, and the loading amount of the first auxiliary agent in the component A is 5-15 wt%.
  5. 5. The preparation process of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, which is characterized in that in the step (4), the second auxiliary agent is one of barium chloride or calcium chloride, the impregnation time is 0.5-2 h, the drying temperature is 180-220 ℃ and the time is 1-3 h, and the loading amount of the second auxiliary agent in the component B is 5-10wt%.
  6. 6. The preparation process of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, which is characterized in that the binder in the step (5) is one of an alkaline aluminum sol solution with a solid content of 5-30wt% or water glass with a modulus of 2.2-3.4 and a solid content of 5-30wt%, wherein the hydrolysis catalyst comprises 70-80 wt% of component A, 10-15 wt% of component B, 5-20wt% of binder, and a drying temperature of 400-550 ℃ for 1-2 hours.
  7. 7. A hydrolysis catalyst for deoxygenation and organic sulfur removal in gas prepared by the method of any one of claims 1-6.
  8. 8. Use of a hydrolysis catalyst for deoxygenation and organic sulfur removal in gas according to claim 7, wherein the hydrolysis catalyst is used for hydrolytic conversion and deoxygenation of high concentration carbon disulphide in steel mill coke oven gas, blast furnace gas or converter gas.
  9. 9. The application of the hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas according to claim 8, wherein the use temperature of the hydrolysis catalyst is 120-200 ℃, the use pressure is 0-1 MPa, and the gas phase space velocity is 2000-4500 h -1 .

Description

Hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, and preparation process and application thereof Technical Field The invention relates to the technical field of purification treatment of coal gas containing organic sulfur, in particular to a hydrolysis catalyst for deoxidizing and removing organic sulfur in coal gas, and a preparation process and application thereof. Background At present, the steel mill is rich in coke oven gas, blast furnace gas, converter gas and the like, and is commonly used as fuel of a steel rolling heating furnace. The gas mainly comprises hydrogen (57% -61%), methane (25% -27%), carbon monoxide (5% -7%), nitrogen (2% -5%), carbon dioxide (2% -3%), oxygen (0.1% -3%), ethane (0.7% -1%), ethylene (2.1% -2.4%), propylene (0.2%), and the like, and also comprises trace sulfur components such as hydrogen sulfide (50-100 mg/Nm 3), carbonyl sulfide (150-200 mg/Nm 3), carbon disulfide (50-350 mg/Nm 3), thiophene (0-50 mg/Nm 3), mercaptan (0-10 mg/Nm 3), and the like, wherein three components such as hydrogen sulfide, carbonyl sulfide and carbon disulfide are mainly used. These sulfur components are combusted and converted to sulfur dioxide which is released into the atmosphere, causing environmental pollution. In the 4th 2019 month, the ecological environment department of China and the like issue opinion about the ultra-low emission of the advanced implementation steel industry, and the ultra-low emission modification is required to be completed by more than 80% of the steel productivity in the whole country before the 2025 year. Only three main sulfur components of hydrogen sulfide, carbonyl sulfide and carbon disulfide in the coal gas are removed, so that the ultra-low emission requirement can be met. According to the characteristics of low temperature (100-300 ℃) of byproduct gas of a steel mill, low heat value, high carbon dioxide and oxygen content, high sulfur component content and high removal depth requirement, the dry desulfurization at the low temperature (25-200 ℃) is an economically feasible technical scheme. (Liang Jianxing et al Low temperature catalyst research progress for synergistic catalytic hydrolysis of carbonyl sulfide and carbon disulfide [ J ]. Material guide, 2021 (21): 1-17.) Aiming at hydrogen sulfide, various iron-based and zinc-based refined desulfurizing agents are successfully developed in the market at present, and can be removed to below 1ppm at the operating temperature of room temperature to 200 ℃. But the fine desulfurizing agents have poor removal effect on organic sulfur such as carbonyl sulfide, carbon disulfide and the like. Aiming at carbonyl sulfide and carbon disulfide in coal gas, a hydrolysis catalyst is usually used for converting the carbonyl sulfide and the carbon disulfide into hydrogen sulfide, and then the refined desulfurizing agent is used for removing the hydrogen sulfide. The principle of hydrolysis of carbonyl sulfide is COS+H 2O→CO2+H2 S. The mechanism of hydrolysis of carbon disulphide is CS 2+ H2O→COS+H2S,COS+H2O→CO2+H2 S. However, the organosulfur hydrolysis catalysts currently on the market are mainly directed to carbonyl sulfide and low concentrations of carbon disulfide. When these hydrolysis catalysts are used in high carbon disulphide systems, they deactivate rapidly, especially in the presence of trace amounts of oxygen, resulting in a process that is not viable. Chinese patent CN96118289 discloses a normal temperature fine removal process for organic sulfur from artificial gas, which adopts a combined process of deoxidizing agent and desulfurizing agent, wherein the deoxidizing agent adopts active carbon as carrier, deoxidizing by catalytic combustion method, generating water vapor, and the optimal condition of active carbon adsorption is dry state, when water vapor exists, the catalytic deoxidizing capability is obviously reduced, and trace oxygen exists, further resulting in the reduction of desulfurizing capability. Chinese patent CN93112631 discloses a high-efficiency molybdenum series deoxidizer and its preparation method and application, the technology has the capability of deep deoxidization under the conditions of sulfur resistance and CO resistance, the carrier adopts active carbon or active alumina (gamma-A1 2O3) and its mixture, the catalytic combustion method is adopted for deoxidization, and the product is water vapor. The deoxidizer has strong deoxidizing capability, but does not have desulfurizing capability. The hydrolysis catalyst patents presently disclosed are also primarily developed for carbonyl sulfide (COS). A variety of hydrolysis catalysts have been developed for carbonyl sulfide (COS) by China petrochemical Co., ltd. CN113181953A, CN109985654B et al also is directed to removal of carbonyl sulfide (COS). CN107497440B discloses a hydrolysis and absorption type desulfurizing agent, which can be used for removing carbon disulfide, the service life is mainly limited by the sul