Efficient desulfurization method for coal gasification gas

Abstract

The invention discloses an efficient desulfurization method of coal gasification gas, which comprises the following steps: adding a composite desulfurizer into a desulfurization device, setting the temperature of the desulfurization device to be 60-80 DEG C, introducing dust removal gas from the bottom of the desulfurization device, and desulfurizing to obtain desulfurized gas; according to the efficient desulfurization method for the coal gasification gas, the modified cross-linking agent and the modified pore-forming agent are prepared, the structure of the composite desulfurizer is optimized, the modified cross-linking agent and the modified pore-forming agent are synergistically matched with a carrier of the modified desulfurizer, and the mechanical strength of the composite desulfurizer is remarkably enhanced; and the specific surface area of the desulfurizing agent is increased through the complex porous structure, so that a novel compound desulfurizing agent is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of coal gas desulfurization, and in particular to a high-efficiency desulfurization method for coal gasification gas. Background Art

[0002] The wear resistance and desulfurization performance of desulfurizers are constantly improving with the development of desulfurization technology. Early desulfurizers such as limestone and lime have poor wear resistance and are prone to powdering or wear during long-term use, resulting in reduced desulfurization efficiency. In addition, the desulfurization capacity is also limited, mainly relying on chemical adsorption, and the effect of removing sulfur dioxide is poor. After entering the 21st century, the application of composite materials, nanomaterials and catalysts has comprehensively improved the mechanical properties and desulfurization performance of desulfurizers. New desulfurizers not only have stronger wear resistance and corrosion resistance, but can also operate stably for a long time under harsh conditions such as high temperature and high pressure, and the desulfurization efficiency has also been greatly improved.

[0003] The prior art CN112691651B discloses a preparation method, a desulfurizer and an application of a desulfurizer, which comprises the following steps: S1, mixing a silicon-containing compound with an aluminum-containing compound to obtain a silicon-aluminum slurry; S2, adding an alkaline solution to the obtained silicon-aluminum slurry, mixing evenly, aging, and obtaining an aged slurry; S3, adding a metal solution to the obtained aged slurry, mixing evenly, and obtaining a solid crude product through gelation and crystallization steps; S4: mixing the obtained solid crude product with a binder to form a mixture, drying, and calcining to obtain a desulfurizer. This method adds metals for ion exchange on the basis of forming a Si-O-Al structure to achieve one-step modification, and the cost of preparing the desulfurizer is low. After adding the metals in IIB, IIB, and VIII for modification, the desulfurization accuracy of the desulfurizer is improved at room temperature, and at the same time, the desulfurizer has a large sulfur capacity.

[0004] However, the above patent produces a colloidal structure by hydrolyzing silicon-aluminum slurry and loading metal components on its surface to obtain a desulfurizer. However, the structure produced by silicon-aluminum hydrolysis is simple and lacks structural modification, resulting in the need to further improve the wear resistance of the material and the effective contact area with sulfur-containing gases, thereby resulting in the need to further improve the mechanical properties and desulfurization performance of the desulfurizer. Summary of the invention

[0005] The object of the present invention is to provide a highly efficient desulfurization method for coal gasification gas, which is used to solve the technical problem that the mechanical properties and desulfurization capacity of the desulfurizer in the desulfurization process in the prior art need to be further improved.

[0006] The purpose of the present invention can be achieved by the following technical solution: A method for efficiently desulfurizing coal gasification gas, comprising the following steps:

[0007] S1. Add the composite solvent and the modified adhesive into a stirring kettle, stir for 5-10 min at room temperature, then add the modified desulfurizer, activator, stabilizer and modified pore-forming agent into the stirring kettle, stir for 30-40 min at room temperature to obtain a precursor solution;

[0008] S2. The precursor solution is transferred to a vacuum drying oven and dried to constant weight, then ground and passed through a 20-40 mesh sieve to obtain a composite desulfurizer, and the composite desulfurizer is added to a desulfurization device, and the temperature of the desulfurization device is set to 180-200°C;

[0009] Reaction principle for preparing composite desulfurizer: Under alkaline conditions, the siloxane structure of the modified adhesive is hydrolyzed to produce a complex gel structure, which combines with the silanol groups on the surface of the modified desulfurizer and the active sites of other auxiliary materials to eventually form a cross-linked structure. The composite desulfurizer is finally prepared through dry grinding.

[0010] S3, performing dust removal treatment on the coal gas to obtain dust-removing gas;

[0011] S4. The dust removal gas is introduced from the bottom of the desulfurization device, and desulfurized gas is obtained after desulfurization.

[0012] Further, in step S1, the composite solvent is obtained by mixing anhydrous ethanol, deionized water and sodium hydroxide powder in a dosage ratio of 100 mL: 20 mL: 3-5 g, the dosage ratio of the composite solvent, modified adhesive, modified desulfurizer, activator, stabilizer and modified pore-forming agent is 60-80 mL: 8-10 g: 20-25 g: 2-5 g: 1-3 g: 5-8 g, and the stirring rate of the reactor is 60-80 rpm;

[0013] Further, in step S2, the activator is one or more of calcium hydroxide and aluminum hydroxide; the stabilizer is one or more of sodium silicate, diammonium hydrogen phosphate and sodium carbonate;

[0014] Furthermore, in step S3, the dust removal operation is as follows: the coal gasification gas is circulated into a cyclone dust collector to obtain intermediate gas I after dust removal, and the intermediate gas I is circulated through a bag filter to obtain dust-removed gas;

[0015] Furthermore, the gas flow rate of the cyclone dust collector is 30000-50000Nm³ / h, and the particle concentration of the coal gasification gas is less than 100mg / Nm 3 The cycle is then ended to obtain intermediate gas I; the gas flow rate of the bag filter is 10000-30000Nm³ / h, and the particle concentration of intermediate gas I is less than 10mg / Nm 3 Finally, the cycle is ended and dust-free gas is obtained.

[0016] Furthermore, the preparation method of the modified desulfurizer comprises the following steps:

[0017] A1. Add hexadecyltrimethylammonium bromide and anhydrous ethanol into a reactor and stir. Add deionized water, sodium hydroxide powder and methyl orthosilicate during stirring. Raise the temperature of the reactor to 40-60° C., keep the reaction temperature for 1-2 hours, and perform post-treatment to obtain a desulfurizer carrier.

[0018] A2. Add the metal salt solution to a water bath reactor and stir. After stirring for 8-10 minutes at room temperature, add the complexing agent and the desulfurizing agent carrier to the reactor. The water bath temperature of the water bath reactor is raised to 60-80°C. The water is evaporated in the water bath until a viscous gel is produced to obtain a desulfurizing agent precursor.

[0019] A3. After aging the desulfurizer precursor at room temperature for 2-4 days, place the desulfurizer precursor in a reactor, raise the temperature of the reactor to 50-60°C, keep it warm and foam for 2-4 hours, then raise the temperature of the reactor to 120°C and introduce oxygen into the reactor, keep it warm for 3-4 hours to obtain a modified desulfurizer.

[0020] The reaction principle for preparing the modified desulfurizer is as follows: under alkaline conditions, methyl orthosilicate is hydrolyzed to produce an internally cross-linked structure of hexadecyltrimethylammonium bromide, which is then acid-washed and dried to form a porous structure. The zinc salt is further cross-linked on the surface of the desulfurizer carrier through a complexing agent. After aging and foaming, the zinc salt is decomposed in an oxygen atmosphere to produce zinc oxide, and finally a modified desulfurizer with a porous structure is prepared.

[0021] Further, in step A1, the stirring rate of the reactor is 60-80rpm, the amount ratio of hexadecyltrimethylammonium bromide, anhydrous ethanol, deionized water, sodium hydroxide powder and methyl orthosilicate is 3-5g:20-25g:20-25mL:2-3g:8-10mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is placed in a 10-15wt% hydrochloric acid solution for ultrasonication for 20-30min, the ultrasonic frequency is 10-20kHz, after the ultrasonication, the filter cake is washed with anhydrous ethanol and deionized water for 3-5 times, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain a desulfurizer carrier;

[0022] Furthermore, in step A2, the stirring rate of the reactor is 60-80rpm, the metal salt solution is a 20-25wt% zinc nitrate solution, the complexing agent is triethanolamine, and the amount ratio of the metal salt solution, the complexing agent and the desulfurizing agent carrier is 20-25mL:2-3mL:6-8g; in step B3, the post-treatment includes: grinding the material, passing through a 10-20 mesh sieve, and obtaining a modified desulfurizing agent.

[0023] Furthermore, the preparation method of the modified adhesive is: 3-aminopropyltriethoxysilane, saturated sodium hydroxide solution and N,N-dimethylformamide are slowly added to a three-necked flask equipped with a thermometer, a stirrer and a cooling reflux device, the temperature of the three-necked flask is heated to 100-120°C, formaldehyde solution is added dropwise to the reactor, the addition is continued for 30-40 minutes, and the mixture is kept warm and refluxed for 60-80 minutes, and the modified adhesive is obtained by post-treatment.

[0024] The reaction equation for preparing the modified adhesive is:

[0025]

[0026] Where: ; “*” represents the active connection site of the organic chain segment.

[0027] The reaction principle for preparing the modified adhesive is as follows: under the catalysis of alkaline and heating conditions, the amino group on 3-aminopropyltriethoxysilane and the aldehyde group on formaldehyde undergo amine-aldehyde condensation reaction, and by controlling the reaction conditions, a cyclic triazine structure is formed to finally prepare the modified adhesive. The mass spectrometry analysis data of the modified adhesive are m / z: 795.7 (100.0%), 796.1 (50.1%), 797.6 (25.1%), 798.2 (7.9%), and 799.1 (2.2%).

[0028] Furthermore, the stirring rate of the reactor is 60-80rpm, the amount ratio of 3-aminopropyltriethoxysilane, sodium hydroxide, N,N-dimethylformamide and formaldehyde solution is 2.0-2.4g:3-5mL:30-36mL:20-30mL, the formaldehyde solution is obtained by mixing formaldehyde and N,N-dimethylformamide at a ratio of 0.2-0.3g:20-30mL, and the post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80-100°C, and reduced pressure distillation is performed until no liquid is extracted to obtain a modified adhesive.

[0029] Furthermore, the preparation method of the modified pore-forming agent comprises the following steps:

[0030] B1, adding activated carbon, N-(3-trimethoxysilylethyl)ethylenediamine, sodium hydroxide powder, deionized water and ethanol into a reactor, raising the temperature of the reactor to 40-60° C., keeping the temperature for 30-40 minutes, and post-treating to obtain modified activated carbon;

[0031] B2. Add modified activated carbon, triethylamine and anhydrous ethanol into a reactor, stir for 5-8 minutes at room temperature, increase the temperature of the reactor to 40-60°C, add glycidol into the reactor, keep the temperature for 1-2 hours, and post-treat to obtain a modified pore-forming agent.

[0032] The reaction equation for preparing the modified pore-forming agent is:

[0033]

[0034] The reaction principle for preparing the modified pore-forming agent is as follows: under alkaline conditions, the silanol groups on N-(3-trimethoxysilylethyl)ethylenediamine are hydrolyzed to produce active structures, which react with active functional groups on the surface of activated carbon to produce cross-linked structures to obtain modified activated carbon. Furthermore, under alkaline conditions, the modified amino groups and secondary amino groups on the surface of the modified activated carbon react with the epoxy groups on glycidol, the epoxy groups are ring-opened and produce cross-linked structures with the modified activated carbon, and finally the modified pore-forming agent is prepared.

[0035] Further, in step B1, the amount ratio of activated carbon, N-(3-trimethoxysilylethyl)ethylenediamine, sodium hydroxide powder, deionized water and ethanol is 8-10g:2-3g:0.3-0.5g:5-10mL:20-30mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water for 3-5 times, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain modified activated carbon;

[0036] Furthermore, in step B2, the stirring rate of the reactor is 60-80rpm, the dosage ratio of modified activated carbon, triethylamine, anhydrous ethanol and glycidol is 4-5g:0.3-0.5g:15-20mL:1-2g, and the post-treatment includes: after the reaction is completed, the temperature of the reactants is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed 3-5 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain a modified pore-forming agent.

[0037] The present invention has the following beneficial effects:

[0038] 1. The present invention provides a method for efficiently desulfurizing coal gasification gas, and optimizes the structure of a composite desulfurizer by preparing a modified cross-linking agent and a modified pore-forming agent. The two cooperate with the carrier of the modified desulfurizer to significantly enhance the mechanical strength of the composite desulfurizer. The active functional groups modified on the surfaces of the two cooperate with the modified desulfurizer during the desulfurization process, and increase the specific surface area of ​​the desulfurizer through a complex porous structure, thereby obtaining a new type of composite desulfurizer.

[0039] 2. The present invention prepares a modified adhesive having a large number of hydroxyl groups on its surface, and the siloxane structure on its surface is combined with the siloxane components on the surface of the modified desulfurizer and the surface active sites of the auxiliary materials. Compared with inorganic cross-linking agents, it has higher stability. In a high-temperature acidic working environment, it can effectively protect the composite material from corrosion and degradation, and cooperate with the modified pore-forming agent with a large number of hydroxyl groups on the surface to maintain its long-term wear resistance and mechanical properties. The siloxane structure can form a fine pore structure during the cross-linking process, which helps to increase the specific surface area of ​​the desulfurizer, thereby improving the adsorption and reaction capacity, thereby improving the desulfurization efficiency of the desulfurizer.

[0040] 3. The present invention obtains a modified desulfurizer by filling zinc oxide components in a high-void silicon skeleton, wherein the presence of the silicon skeleton can effectively improve the thermal stability of the entire desulfurizer, thereby ensuring the long-term use effect of the desulfurizer in a high-temperature operating environment, and cooperates with the modified pore-forming agent to effectively increase the surface area of ​​the desulfurizer, improve its adsorption and reaction activity, thereby significantly improving the desulfurization efficiency of the desulfurizer, and the silicon skeleton provides a stable supporting structure for the modified desulfurizer, which helps to improve the overall mechanical strength of the desulfurizer, and prevent zinc oxide from falling off or breaking due to high temperature, airflow or impact during the desulfurization process, thereby significantly improving the mechanical properties of the modified desulfurizer. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The activated carbon used in the present invention is purchased from Chengde Yuanyang Activated Carbon Manufacturing Co., Ltd. and the product name is air purification activated carbon.

[0043] Example 1

[0044] This embodiment provides a method for preparing a modified pore-forming agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0045] Step I: Preparation of modified activated carbon

[0046] Weigh: 800.0g activated carbon, 200.0g N-(3-trimethoxysilylethyl)ethylenediamine, 30.0g sodium hydroxide powder, 500.0mL deionized water and 2000.0mL ethanol and add them into a reactor, raise the temperature of the reactor to 40°C, and keep the reaction for 30 minutes. After the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is washed 3 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain modified activated carbon.

[0047] Step II: Preparation of modified pore-forming agent

[0048] Weigh: 400.0g modified activated carbon, 30.0g triethylamine and 1500.0mL anhydrous ethanol are added to the reactor. The stirring rate of the reactor is 60rpm. After stirring at room temperature for 5min, the temperature of the reactor is increased to 40°C and 100.0g glycidol is added to the reactor. The reaction is kept warm for 1h. After the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed 3 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a modified pore-forming agent.

[0049] Example 2

[0050] This embodiment provides a method for preparing a modified pore-forming agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0051] Step I: Preparation of modified activated carbon

[0052] Weigh: 1000.0g activated carbon, 300.0g N-(3-trimethoxysilylethyl)ethylenediamine, 50.0g sodium hydroxide powder, 1000.0mL deionized water and 3000.0mL ethanol and add them into a reactor, raise the temperature of the reactor to 60°C, and keep the reaction for 40 minutes. After the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is washed 5 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain modified activated carbon.

[0053] Step II: Preparation of modified pore-forming agent

[0054] Weigh: 500.0g modified activated carbon, 50.0g triethylamine and 2000.0mL anhydrous ethanol are added to the reactor. The stirring rate of the reactor is 80rpm. After stirring at room temperature for 8min, the temperature of the reactor is increased to 60°C and 200.0g glycidol is added to the reactor. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactants is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed 5 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a modified pore-forming agent.

[0055] Example 3

[0056] This embodiment provides a method for preparing a modified pore-forming agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0057] Step I: Preparation of modified activated carbon

[0058] Weigh: 900.0g activated carbon, 250.0g N-(3-trimethoxysilylethyl)ethylenediamine, 40.0g sodium hydroxide powder, 750.0mL deionized water and 2500.0mL ethanol and add them into the reactor, the temperature of the reactor is raised to 50°C, and the reaction is kept warm for 36 minutes. After the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed 4 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C, and vacuum dried until the filter cake has a constant weight to obtain modified activated carbon.

[0059] Step II: Preparation of modified pore-forming agent

[0060] Weigh: 450.0g modified activated carbon, 40.0g triethylamine and 1800.0mL anhydrous ethanol are added to the reactor. The stirring rate of the reactor is 70rpm. After stirring at room temperature for 7 minutes, the temperature of the reactor is increased to 50°C and 160.0g glycidol is added to the reactor. The reaction is kept warm for 2 hours. After the reaction is completed, the temperature of the reactant is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed 4 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a modified pore-forming agent.

[0061] Example 4

[0062] This embodiment provides a method for preparing a modified adhesive for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0063] Weigh: 20.0 g of formaldehyde and 2000.0 mL of N,N-dimethylformamide and mix to obtain a formaldehyde solution;

[0064] Weigh: 200.0g 3-aminopropyltriethoxysilane, 300.0mL saturated sodium hydroxide solution and 3000.0mL N,N-dimethylformamide, slowly add into a three-necked flask equipped with a thermometer, a stirrer and a cooling reflux device, heat the three-necked flask to 100°C, add 2000.0mL formaldehyde solution dropwise into the reactor, continue to add for 30min, keep warm and reflux for 60min, after the reaction is completed, cool the reactor to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 80°C, and distill under reduced pressure until no liquid is produced to obtain a modified adhesive.

[0065] Example 5

[0066] This embodiment provides a method for preparing a modified adhesive for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0067] Weigh: 30.0 g of formaldehyde and 3000.0 mL of N,N-dimethylformamide and mix to obtain a formaldehyde solution;

[0068] Weigh: 240.0g 3-aminopropyltriethoxysilane, 500.0mL saturated sodium hydroxide solution and 3600.0mL N,N-dimethylformamide, slowly add into a three-necked flask equipped with a thermometer, a stirrer and a cooling reflux device, heat the three-necked flask to 120°C, add 3000.0mL formaldehyde solution dropwise into the reactor, continue to add for 40min, keep warm and reflux for 80min, after the reaction is completed, cool the reactor to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 100°C, and distill under reduced pressure until no liquid is produced to obtain a modified adhesive.

[0069] Example 6

[0070] This embodiment provides a method for preparing a modified adhesive for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0071] Weigh: 250.0 g of formaldehyde and 2500.0 mL of N,N-dimethylformamide and mix to obtain a formaldehyde solution;

[0072] Weigh: 210.0g 3-aminopropyltriethoxysilane, 400.0mL saturated sodium hydroxide solution and 3200.0mL N,N-dimethylformamide, slowly add into a three-necked flask equipped with a thermometer, a stirrer and a cooling reflux device, heat the three-necked flask to 120°C, add 2500.0mL formaldehyde solution dropwise into the reactor, continue to add for 36min, keep warm and reflux for 72min, after the reaction is completed, cool the reactor to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 90°C, and distill under reduced pressure until no liquid is produced to obtain a modified adhesive.

[0073] Example 7

[0074] This embodiment provides a method for preparing a modified desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0075] Step ①: Preparation of desulfurization agent carrier

[0076] Weigh: 300.0g of hexadecyltrimethylammonium bromide and 2000.0g of anhydrous ethanol are added to a reactor and stirred at a stirring rate of 60rpm. During the stirring process, 2000.0mL of deionized water, 200.0g of sodium hydroxide powder and 800.0mL of methyl orthosilicate are added, and the temperature of the reactor is raised to 40°C. The reaction is kept warm for 1h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a 10wt% hydrochloric acid solution for ultrasonication for 20min at an ultrasonic frequency of 10kHz. After the ultrasonication is completed, the filter cake is washed 3 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a desulfurizer carrier.

[0077] Step ②: Preparation of desulfurization agent precursor

[0078] Weigh: 2000.0mL 20wt% zinc nitrate solution is added to a water bath reactor and stirred at a stirring rate of 60rpm. After stirring for 8 minutes at room temperature, 200.0mL triethanolamine and 600.0g desulfurizer carrier are added to the reactor. The water bath temperature of the water bath reactor is raised to 60°C. The water is evaporated in the water bath to produce a viscous gel to obtain a desulfurizer precursor.

[0079] Step ③: Preparation of modified desulfurizing agent

[0080] Weigh: After the desulfurizer precursor is aged at room temperature for 2 days, the desulfurizer precursor is placed in a reactor, the temperature of the reactor is increased to 50°C, and after heat preservation and foaming for 2 hours, the temperature of the reactor is increased to 120°C and oxygen is introduced into the reactor. After heat preservation for 3 hours, the material is ground and passed through a 10-mesh sieve to obtain a modified desulfurizer.

[0081] Example 8

[0082] This embodiment provides a method for preparing a modified desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0083] Step ①: Preparation of desulfurization agent carrier

[0084] Weigh: 500.0g of hexadecyltrimethylammonium bromide and 2500.0g of anhydrous ethanol are added to a reactor and stirred at a stirring rate of 80rpm. During the stirring process, 2500.0mL of deionized water, 300.0g of sodium hydroxide powder and 1000.0mL of methyl orthosilicate are added, and the temperature of the reactor is raised to 60°C. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a 15wt% hydrochloric acid solution for ultrasonication for 30min at a frequency of 20kHz. After the ultrasonication is completed, the filter cake is washed 5 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a desulfurizer carrier.

[0085] Step ②: Preparation of desulfurization agent precursor

[0086] Weigh: 2500.0mL 25wt% zinc nitrate solution is added to a water bath reactor and stirred at a stirring rate of 80rpm. After stirring for 10min at room temperature, 300.0mL triethanolamine and 800.0g desulfurizer carrier are added to the reactor. The water bath temperature of the water bath reactor is raised to 80°C. The water is evaporated in the water bath to produce a viscous gel to obtain a desulfurizer precursor.

[0087] Step ③: Preparation of modified desulfurizing agent

[0088] Weigh: After the desulfurizer precursor is aged at room temperature for 4 days, the desulfurizer precursor is placed in a reactor, the temperature of the reactor is increased to 60°C, and after insulation and foaming for 4 hours, the temperature of the reactor is increased to 120°C and oxygen is introduced into the reactor. After insulation treatment for 4 hours, the material is ground and passed through a 20-mesh sieve to obtain a modified desulfurizer.

[0089] Example 9

[0090] This embodiment provides a method for preparing a modified desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0091] Step ①: Preparation of desulfurization agent carrier

[0092] Weigh: 400.0g of hexadecyltrimethylammonium bromide and 2100.0g of anhydrous ethanol are added to a reactor and stirred at a stirring rate of 70rpm. While stirring, 2100.0mL of deionized water, 210.0g of sodium hydroxide powder and 900.0mL of methyl orthosilicate are added, and the temperature of the reactor is raised to 50°C. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a 12wt% hydrochloric acid solution for ultrasonication for 25min at a frequency of 16kHz. After the ultrasonication is completed, the filter cake is washed 4 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a desulfurizer carrier.

[0093] Step ②: Preparation of desulfurization agent precursor

[0094] Weigh: 2100.0mL 24wt% zinc nitrate solution is added to a water bath reactor and stirred at a stirring rate of 70rpm. After stirring for 9 minutes at room temperature, 240.0mL triethanolamine and 700.0g desulfurizer carrier are added to the reactor. The water bath temperature of the water bath reactor is raised to 70°C. The water is evaporated in the water bath to produce a viscous gel to obtain a desulfurizer precursor.

[0095] Step ③: Preparation of modified desulfurizing agent

[0096] Weigh: After the desulfurizer precursor is aged at room temperature for 3 days, the desulfurizer precursor is placed in a reactor, the reactor temperature is increased to 54°C, and after heat preservation and foaming for 3 hours, the reactor temperature is increased to 120°C and oxygen is introduced into the reactor. After heat preservation treatment for 4 hours, the material is ground and passed through a 15-mesh sieve to obtain a modified desulfurizer.

[0097] Example 10

[0098] This embodiment provides a method for preparing a composite desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0099] Step 1: Prepare precursor solution

[0100] Weigh: 1000.0 mL of anhydrous ethanol, 200.0 mL of deionized water and 30.0 g of sodium hydroxide powder and mix to obtain a composite solvent;

[0101] Weigh: 6000.0 mL of the composite solvent and 800.0 g of the modified adhesive prepared in Example 4 are added to a stirring tank at a stirring rate of 60 rpm. After stirring at room temperature for 5 min, 2000.0 g of the modified desulfurizer prepared in Example 7, 200.0 g of the activator, 100.0 g of the stabilizer and 500.0 g of the modified pore-forming agent prepared in Example 1 are added to the stirring tank, and stirred at room temperature for 30 min to obtain a precursor solution.

[0102] Step 2: Preparation of composite desulfurizer

[0103] Weighing: The precursor solution is transferred to a vacuum drying oven and dried to constant weight, then ground and passed through a 20-mesh sieve to obtain a composite desulfurizer, which is added to a desulfurization device, and the temperature of the desulfurization device is set to 180°C.

[0104] Step 3: Prepare dust removal gas

[0105] The coal gasification gas is circulated into the cyclone dust collector for dust removal. The gas flow rate is set to 30000Nm³ / h. When the particle concentration of the coal gasification gas is lower than 100mg / Nm 3 The cycle is then ended to obtain intermediate gas I, which is circulated through the bag filter with a gas flow rate of 10000 Nm³ / h. When the particle concentration of the coal gasification gas is lower than 10 mg / Nm 3 Finally, the cycle is ended and dust-free gas is obtained.

[0106] Step 4: Preparation of desulfurized gas

[0107] The dust removal gas is introduced into the bottom of the desulfurization device and desulfurized gas is obtained after desulfurization.

[0108] Embodiment 11

[0109] This embodiment provides a method for preparing a composite desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0110] Step 1: Prepare precursor solution

[0111] Weigh: 1000.0 mL of anhydrous ethanol, 200.0 mL of deionized water and 50.0 g of sodium hydroxide powder and mix to obtain a composite solvent;

[0112] Weigh: 8000.0 mL of the composite solvent and 1000.0 g of the modified adhesive prepared in Example 5 are added to a stirring tank at a stirring rate of 80 rpm. After stirring at room temperature for 10 min, 2500.0 g of the modified desulfurizer prepared in Example 8, 500.0 g of the activator, 300.0 g of the stabilizer and 800.0 g of the modified pore-forming agent prepared in Example 2 are added to the stirring tank, and stirred at room temperature for 40 min to obtain a precursor solution.

[0113] Step 2: Preparation of composite desulfurizer

[0114] Weighing: The precursor solution is transferred to a vacuum drying oven and dried to constant weight, then ground and passed through a 40-mesh sieve to obtain a composite desulfurizer, which is added to a desulfurization device, and the temperature of the desulfurization device is set to 200°C.

[0115] Step 3: Prepare dust removal gas

[0116] The coal gasification gas is circulated into the cyclone dust collector for dust removal. The gas flow rate is set to 50000Nm³ / h. When the particle concentration of the coal gasification gas is lower than 100mg / Nm 3 The cycle is then terminated to obtain intermediate gas I, which is circulated through the bag filter with a gas flow rate of 30,000 Nm³ / h. When the particle concentration of the coal gasification gas is lower than 10 mg / Nm 3 Finally, the cycle is ended and dust-free gas is obtained.

[0117] Step 4: Preparation of desulfurized gas

[0118] The dust removal gas is introduced into the bottom of the desulfurization device and desulfurized gas is obtained after desulfurization.

[0119] Example 12

[0120] This embodiment provides a method for preparing a composite desulfurizing agent for a highly efficient desulfurization method of coal gasification gas, comprising the following steps:

[0121] Step 1: Prepare precursor solution

[0122] Weigh: 1000.0 mL of anhydrous ethanol, 200.0 mL of deionized water and 40.0 g of sodium hydroxide powder and mix to obtain a composite solvent;

[0123] Weigh: 7000.0 mL of the composite solvent and 900.0 g of the modified adhesive prepared in Example 6 are added to a stirring tank at a stirring rate of 70 rpm. After stirring at room temperature for 8 min, 2400.0 g of the modified desulfurizer prepared in Example 9, 300.0 g of the activator, 200.0 g of the stabilizer and 720.0 g of the modified pore-forming agent prepared in Example 3 are added to the stirring tank, and stirred at room temperature for 40 min to obtain a precursor solution.

[0124] Step 2: Preparation of composite desulfurizer

[0125] Weighing: The precursor solution is transferred to a vacuum drying oven and dried to constant weight, then ground and passed through a 30-mesh sieve to obtain a composite desulfurizer.

[0126] Step 3: Prepare dust removal gas

[0127] The coal gasification gas is circulated into the cyclone dust collector for dust removal. The gas flow rate is set to 40000Nm³ / h. When the particle concentration of the coal gasification gas is lower than 100mg / Nm 3 The cycle is ended and intermediate gas I is obtained. Intermediate gas I is circulated through the bag filter with a gas flow rate of 20000Nm³ / h. When the particle concentration of the coal gasification gas is lower than 10mg / Nm 3 Finally, the cycle is ended and dust-free gas is obtained.

[0128] Step 4: Preparation of desulfurized gas

[0129] The dust removal gas is introduced into the bottom of the desulfurization device and desulfurized gas is obtained after desulfurization.

[0130] Comparative Example 1

[0131] The difference between this comparative example and Example 12 is that, in the process of preparing the composite desulfurizer used in step 2, an equal amount of water glass is used to replace the modified adhesive in step (1).

[0132] Comparative Example 2

[0133] The difference between this comparative example and Example 12 is that, in the process of preparing the composite desulfurizer used in step 2, an equal amount of nano zinc oxide is used to replace the modified desulfurizer in step (1).

[0134] Comparative Example 3

[0135] The difference between this comparative example and Example 12 is that, in the process of preparing the composite desulfurizer used in step 2, an equal amount of activated carbon is used to replace the modified pore-forming agent in step (1).

[0136] Performance Testing:

[0137] The penetration sulfur capacity, average particle radial crushing force, average particle point crushing force and abrasion rate of the composite desulfurizer used in Examples 13-15 were measured with reference to the standard HG / T 2508-2012 "Zinc Oxide Desulfurizer";

[0138] The sulfide content of the desulfurized gas of Examples 13-15 was determined with reference to the standard GB / T 33318-2016 “Determination of sulfide in gas analysis - Sulfur chemiluminescence gas chromatography”. The specific data are shown in Table 1.

[0139] Table 1-Performance test data of each sample

[0140]

[0141] Data Analysis:

[0142] Comparative analysis of the data in Table 1 above shows that the composite desulfurizer prepared by the present invention has a penetration sulfur capacity of 34%, an average particle radial crushing force of 53 N·cm, an average particle point crushing force of 22 N, an abrasion rate of 3.2%, and a sulfide content of the desulfurized gas obtained after desulfurization of 6.5 mg·m -3 , all data are better than the comparative example;

[0143] It is explained that the present invention prepares a modified adhesive having a large number of hydroxyl groups on the surface, and the siloxane structure on the surface is combined with the siloxane component on the surface of the modified desulfurizer and the surface active sites of the auxiliary material. Compared with the inorganic cross-linking agent, it has higher stability, can effectively protect the composite material from corrosion and degradation in a high temperature and acidic working environment, and cooperates with the modified pore-forming agent with a large number of hydroxyl groups on the surface to maintain its long-term wear resistance and mechanical properties. The siloxane structure can form a fine pore structure during the cross-linking process, which helps to increase the specific surface area of ​​the desulfurizer, thereby improving the adsorption and reaction capacity, thereby improving the desulfurization efficiency of the desulfurizer;

[0144] It is explained that the present invention obtains a modified desulfurizer by filling a zinc oxide component in a high-void silicon skeleton, wherein the presence of the silicon skeleton can effectively improve the thermal stability of the entire desulfurizer, thereby ensuring the long-term use effect of the desulfurizer in a high-temperature operating environment, and cooperates with the modified pore-forming agent to effectively increase the surface area of ​​the desulfurizer, improve its adsorption and reaction activity, thereby significantly improving the desulfurization efficiency of the desulfurizer, and the silicon skeleton provides a stable supporting structure for the modified desulfurizer, which helps to improve the overall mechanical strength of the desulfurizer, and prevents zinc oxide from falling off or breaking due to high temperature, airflow or impact during the desulfurization process, thereby significantly improving the mechanical properties of the modified desulfurizer;

[0145] Description: The present invention provides a method for efficiently desulfurizing coal gasification gas, and optimizes the structure of a composite desulfurizer by preparing a modified cross-linking agent and a modified pore-forming agent. The two cooperate with the carrier of the modified desulfurizer to significantly enhance the mechanical strength of the composite desulfurizer. The active functional groups modified on the surfaces of the two cooperate with the modified desulfurizer during the desulfurization process, and increase the specific surface area of ​​the desulfurizer through a complex porous structure, thereby obtaining a new type of composite desulfurizer.

[0146] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for efficiently desulfurizing coal gasification gas, characterized in that: The following steps are involved: S1. Add the composite solvent and the modified adhesive into a stirring kettle, stir for 5-10 min at room temperature, then add the modified desulfurizer, activator, stabilizer and modified pore-forming agent into the stirring kettle, stir for 30-40 min at room temperature to obtain a precursor solution; S2. The precursor solution is transferred to a vacuum drying oven and dried to constant weight, then ground and passed through a 20-40 mesh sieve to obtain a composite desulfurizer, and the composite desulfurizer is added to a desulfurization device, and the temperature of the desulfurization device is set to 180-200°C; S3, performing dust removal treatment on the coal gas to obtain dust-removing gas; S4. The dust removal gas is introduced from the bottom of the desulfurization device, and desulfurized gas is obtained after desulfurization.

2. The method for efficient desulfurization of coal gasification gas according to claim 1, characterized in that: In step S1, the composite solvent is obtained by mixing anhydrous ethanol, deionized water and sodium hydroxide powder in a dosage ratio of 100 mL: 20 mL: 3-5 g, and the dosage ratio of the composite solvent, modified adhesive, modified desulfurizer, activator, stabilizer and modified pore-forming agent is 60-80 mL: 8-10 g: 20-25 g: 2-5 g: 1-3 g: 5-8 g.

3. The method for efficient desulfurization of coal gasification gas according to claim 1, characterized in that: The preparation method of the modified desulfurizer comprises the following steps: A1. Add hexadecyltrimethylammonium bromide and anhydrous ethanol into a reactor and stir. Add deionized water, sodium hydroxide powder and methyl orthosilicate during stirring. Raise the temperature of the reactor to 40-60° C., keep the reaction temperature for 1-2 hours, and perform post-treatment to obtain a desulfurizer carrier. A2. Add the metal salt solution to a water bath reactor and stir. After stirring for 8-10 minutes at room temperature, add the complexing agent and the desulfurizing agent carrier to the reactor. The water bath temperature of the water bath reactor is raised to 60-80°C. The water is evaporated in the water bath until a viscous gel is produced to obtain a desulfurizing agent precursor. A3. After aging the desulfurizer precursor at room temperature for 2-4 days, place the desulfurizer precursor in a reactor, raise the temperature of the reactor to 50-60°C, keep it warm and foam for 2-4 hours, then raise the temperature of the reactor to 120°C and introduce oxygen into the reactor, keep it warm for 3-4 hours, and post-treat to obtain a modified desulfurizer.

4. The method for efficient desulfurization of coal gasification gas according to claim 3, characterized in that: In step A1, the dosage ratio of hexadecyltrimethylammonium bromide, anhydrous ethanol, deionized water, sodium hydroxide powder and methyl orthosilicate is 3-5g:20-25g:20-25mL:2-3g:8-10mL; in step A2, the metal salt solution is a 20-25wt% zinc nitrate solution, the complexing agent is triethanolamine, and the dosage ratio of the metal salt solution, the complexing agent and the desulfurization agent carrier is 20-25mL:2-3mL:6-8g.

5. The method for efficient desulfurization of coal gasification gas according to claim 1, characterized in that: The preparation method of the modified adhesive is as follows: 3-aminopropyltriethoxysilane, saturated sodium hydroxide solution and N,N-dimethylformamide are slowly added into a three-necked flask equipped with a thermometer, a stirrer and a cooling reflux device; after the temperature of the three-necked flask is heated to 100-120° C., formaldehyde solution is dripped into a reaction kettle; after the dripping is continued for 30-40 minutes, the solution is kept warm and refluxed for 60-80 minutes, and the modified adhesive is obtained by post-treatment.

6. The method for efficient desulfurization of coal gasification gas according to claim 5, characterized in that: The dosage ratio of 3-aminopropyltriethoxysilane, sodium hydroxide, N,N-dimethylformamide and formaldehyde solution is 2.0-2.4g:3-5mL:30-36mL:20-30mL, and the formaldehyde solution is obtained by mixing formaldehyde and N,N-dimethylformamide at a dosage ratio of 0.2-0.3g:20-30mL.

7. The method for efficient desulfurization of coal gasification gas according to claim 1, characterized in that: The preparation method of the modified pore-forming agent comprises the following steps: B1, adding activated carbon, N-(3-trimethoxysilylethyl)ethylenediamine, sodium hydroxide powder, deionized water and ethanol into a reactor, raising the temperature of the reactor to 40-60° C., keeping the temperature for 30-40 minutes, and post-treating to obtain modified activated carbon; B2. Add modified activated carbon, triethylamine and anhydrous ethanol into a reactor, stir for 5-8 minutes at room temperature, increase the temperature of the reactor to 40-60°C, add glycidol into the reactor, keep the temperature for 1-2 hours, and post-treat to obtain a modified pore-forming agent.

8. The method for efficient desulfurization of coal gasification gas according to claim 7, characterized in that: In step B1, the amount ratio of activated carbon, N-(3-trimethoxysilylethyl)ethylenediamine, sodium hydroxide powder, deionized water and ethanol is 8-10g:2-3g:0.3-0.5g:5-10mL:20-30mL; in step B2, the amount ratio of modified activated carbon, triethylamine, anhydrous ethanol and glycidol is 4-5g:0.3-0.5g:15-20mL:1-2g.

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