Preparation method of silicon oxide-coated iron-cobalt catalyst and application thereof in synthesis of COS

Abstract

The application discloses a preparation method of a silicon oxide-wrapped iron-cobalt catalyst and application of the catalyst in synthesis of COS, and specifically comprises the following steps: dissolving iron ammonium citrate and cobalt chloride in deionized water, adding ethylene glycol and urea, uniformly stirring and mixing, and fully reacting, and then performing spray drying to obtain iron-cobalt composite oxide powder; mixing the powder with organic silicate and a solvent, fully stirring, adding water, then heating to 80-90 DEG C and keeping the temperature, stirring into a gelatinous state, drying, and then calcining to obtain silicon-containing iron-cobalt composite oxide; adding the powder to a binder, a pore-forming agent and deionized water, kneading, extruding into a strip, and then drying and calcining again to obtain the silicon oxide-wrapped iron-cobalt catalyst; and the catalyst is used for synthesizing COS after being sulfidized. The catalyst prepared by the application has the characteristics of long service life, high mechanical strength, low loss rate and strong anti-pulverization capacity, and when the catalyst is used in dry preparation of COS, the catalyst has high CO conversion rate and good selectivity of the product COS.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalysts, in particular to a preparation method of a silicon oxide-coated iron-cobalt catalyst and application thereof in synthesis of COS. BACKGROUND

[0002] Carbonyl sulfide, chemical formula COS, also known as carbon oxysulfide, was first synthesized by a Hungarian scientist Karoly Thanz in 1867. In 1970, the Ihar Chemical Industry Company in Japan first realized large-scale industrial production. It is often used as an intermediate raw material in chemical reactions and is widely used in the synthesis of pesticides, medicines and other chemical products. It can also be used as a fumigant for the protection of grain storage. In recent years, high-purity COS has been used as a substitute for fluorine gas in the etching of electronic components, effectively reducing the emission of original fluorine gas. With the increasing attention of governments to environmental protection, COS, which has less impact on the environment than etching gas in the manufacturing of electronic chips and integrated circuits, will receive more and more attention, and its demand will increase rapidly in the future.

[0003] At present, there are two general methods for synthesizing carbonyl sulfide: wet method and dry method. The most commonly used wet process is the reaction of ammonium thiocyanate with sulfuric acid of a certain concentration. For example, CN110127702A discloses a method and device for preparing carbonyl sulfide gas, which comprises adding ammonium thiocyanate solution and concentrated sulfuric acid into a solution containing sulfuric acid of a certain concentration to generate carbonyl sulfide gas. The generated carbonyl sulfide gas is condensed, dried, compressed and filled. The dry process synthesis method is to react CO with sulfur vapor under the action of a catalyst to generate COS. For example, CN205653172U, CN205683986U and CN114669298A disclose that CO and sulfur vapor can react to generate carbonyl sulfide under the condition of a catalyst (such as calcium chloride, iron sulfide, etc.). This method has the characteristics of simple process, high yield, environmental friendliness, etc., and is a commonly used method for industrial production of carbonyl sulfide gas. However, the catalysts used in the dry production of carbonyl sulfide are generally molecular sieves and metal sulfide materials. The selectivity of molecular sieves to COS is relatively poor, generally only about 65%. The activity and selectivity of metal sulfide catalysts such as NiS, CrS, CoS, WS, SnS and FeS can reach more than 90%. The metal sulfide catalysts often have a pulverization phenomenon, which leads to easy deactivation of the catalysts. Therefore, such catalysts generally need to be replaced after one month of use, and the service life is relatively short. SUMMARY

[0004] In view of the technical defects of the prior art catalysts, such as easy pulverization, short service life and poor product selectivity, the application provides a preparation method of a silicon oxide-coated iron-cobalt catalyst, and a catalyst with strong anti-pulverization performance for synthesizing COS is prepared. Compared with the prior art catalysts, the catalyst has the characteristics of long service life, high mechanical strength, low loss rate and strong anti-pulverization capability, and has high CO conversion rate and good product COS selectivity during the dry method preparation of COS.

[0005] The application adopts the following technical scheme:

[0006] A preparation method of a silicon oxide-coated iron-cobalt catalyst, comprising the following steps:

[0007] S1, dissolve iron ammonium citrate and cobalt chloride in deionized water, add ethylene glycol and urea, and stir the mixed solution until it is uniform, then react the solution at 120-180 DEG C for 2-24 hours, and then spray dry the mixture to obtain iron-cobalt composite oxide powder;

[0008] S2, mix the iron-cobalt composite oxide powder with organosilicate and solvent and fully stir for 1 hour, then add deionized water and continue to stir for 2 hours, then heat the mixed solution to 80-90 DEG C at a rate of 2 DEG C / min and keep the temperature constant, and continue to stir until the solution becomes a gel, to obtain a gel intermediate;

[0009] S3, dry the gel intermediate at 120-150 DEG C for 12 hours, and then calcine it at 700-900 DEG C for 4-10 hours to obtain silicon-containing iron-cobalt composite oxide;

[0010] S4, crush the silicon-containing iron-cobalt composite oxide into a powder with a mesh size of 120-200, then add a binder, a pore-forming agent and deionized water, knead for 2-6 hours, extrude into a strip, and then dry and calcine again to obtain the required silicon oxide-coated iron-cobalt catalyst.

[0011] The mass ratio of iron ammonium citrate, cobalt chloride, deionized water, ethylene glycol and urea added in step S1 is (1-5):(1-4):(50-100):(1-2):(1-5).

[0012] The mass-volume ratio of the iron-cobalt composite oxide powder, organosilicate and solvent added in step S2 is (75-80)g:200ml:(400-500)ml.

[0013] The volume of the deionized water added in step S2 is greater than the sum of the volumes of the organosilicate and the solvent.

[0014] The organic silicate added in the step S2 is one or more of ethyl orthosilicate, butyl orthosilicate, tetraisopropyl orthosilicate and tetraethyl orthosilicate; and the solvent added is one or more of ethanol, acetone, isopropyl alcohol and hexane.

[0015] The mass ratio of the iron-cobalt composite oxide powder, the binder, the pore-forming agent and the deionized water added in the step S4 is 100:(10-30):(15-35):20.

[0016] The binder added in the step S4 is one or more of silica sol solution, aluminum hydroxide sol solution and sodium carboxymethyl cellulose solution; and the pore-forming agent added is one or more of asphalt, starch, sucrose and phenolic resin.

[0017] The drying temperature in the step S4 is 120-150 DEG C, the drying time is 8 hours, the calcination temperature is 450-600 DEG C and the calcination time is 4-24 hours.

[0018] The silicon oxide-coated iron-cobalt catalyst prepared by the preparation method of the silicon oxide-coated iron-cobalt catalyst is used for synthesizing COS after being sulfidized.

[0019] The technical scheme of the present application has the following advantages:

[0020] The preparation method of the silicon oxide-coated iron-cobalt catalyst provided by the present application prepares a catalyst for synthesizing COS with strong anti-pulverization performance. Compared with the existing commercial catalyst, the catalyst has the characteristics of long service life, high mechanical strength, low loss rate and strong anti-pulverization ability, and has high CO conversion rate and good selectivity of product COS when used for dry preparation of COS. DETAILED DESCRIPTION

[0021] The technical scheme of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] Embodiment 1:

[0023] The present embodiment provides a preparation method of a sulfidized state hydrodeoxygenation and isomerization catalyst, comprising the following steps:

[0024] S1, dissolve 66 grams of iron ammonium citrate and 52 grams of cobalt chloride in 1200 ml of deionized water, add 65 grams of ethylene glycol and 38 grams of urea, and stir the mixed solution to be uniform, then put the mixed solution in a 2L stainless steel reaction kettle and react at 150 DEG C for 4 hours, then spray dry the mixed solution to obtain an iron-cobalt composite oxide powder;

[0025] S2, 80 grams of iron-cobalt composite oxide powder is stirred with 200 ml of ethyl silicate and 500 ml of ethanol for 1 hour, then 750 ml of deionized water is added, and stirring is continued for 2 hours, then the mixed solution is heated to 80°C at a rate of 2°C / min, and then the temperature is kept constant at this temperature, and stirring is continued until the solution becomes a gel, to obtain a gel intermediate;

[0026] S3, the gel gel intermediate is dried at 120°C for 12 hours, and then calcined at 900°C for 4 hours to obtain a silicon-containing iron-cobalt composite oxide;

[0027] S4, after the silicon-containing iron-cobalt composite oxide is crushed and sieved into a 200-mesh powder, 30 grams of aluminum hydroxide sol, 20 grams of pitch powder and 20 ml of water are added and kneaded for 5 hours, then extruded into a columnar sample, and then dried at 150°C and calcined at 600°C for 4 hours to obtain a silicon oxide-coated iron-cobalt catalyst.

[0028] The embodiment also provides an application of the silicon oxide-coated iron-cobalt catalyst in synthesis of COS, which is specifically as follows:

[0029] After 10 ml of the above catalyst is treated by hydrogen sulfide sulfuration at 450°C for 24 hours, CO gas and sulfur steam are introduced for reaction to synthesize COS, and the space velocity of the catalyst is 450h -1 The concentration of the generated product COS is 93.2%, and the concentration of COS after the catalyst is continuously used for 10 days is still greater than 90.0%, and the pulverization rate of the catalyst is less than 2.8%.

[0030] Example 2:

[0031] The embodiment provides a preparation method of a sulfuration state hydrodeoxygenation and isomerization catalyst, which comprises the following steps:

[0032] S1, 600 grams of iron ammonium citrate and 500 grams of cobalt chloride are dissolved in 15 L of deionized water, then 800 grams of ethylene glycol and 400 grams of urea are added, and the mixed solution after being uniformly stirred is placed in a 20 L stainless steel reaction kettle and reacted at 180°C for 10 hours, then the mixed solution is spray dried to obtain iron-cobalt composite oxide powder;

[0033] S2, 750 grams of sample powder is stirred with 2 L of ethyl silicate and 5 L of ethanol for 1 hour, then 7.5 L of deionized water is added, and stirring is continued for 4 hours, then the mixed solution is heated to 90°C at a rate of 2°C / min, and then the temperature is kept constant at this temperature, and stirring is continued until the solution becomes a gel, to obtain a gel intermediate;

[0034] S3, drying the gel intermediate at 150°C for 12 hours, and then calcining at 800°C for 4 hours to obtain a silicon-containing iron-cobalt composite oxide;

[0035] S4, crushing and sieving the silicon-containing iron-cobalt composite oxide into a powder with a mesh size of 160, then adding 200 g of sodium carboxymethyl cellulose, 180 g of starch, and 220 ml of water to knead for 6 hours, extruding into a columnar sample, drying again at 120°C, and calcining at 700°C for 4 hours to obtain a silicon-coated iron-cobalt catalyst.

[0036] The embodiment also provides an application of the silicon-coated iron-cobalt catalyst in the synthesis of COS, and the application is as follows:

[0037] After 80 ml of the catalyst is treated with hydrogen sulfide at 450°C for 24 hours, CO gas and sulfur vapor are introduced to react and synthesize COS, and the space velocity of the catalyst is 350 h-1. -1 The concentration of the generated product COS is 92.6%, and the concentration of COS after the catalyst is continuously used for 10 days is still greater than 90.0%, and the pulverization rate of the catalyst is less than 3.7%.

[0038] Example 3:

[0039] The embodiment provides a preparation method of a sulfided hydrodeoxygenation and isomerization catalyst, and the method comprises the following steps:

[0040] S1, dissolving 300 g of iron ammonium citrate and 240 g of cobalt chloride in 6 L of deionized water, then adding 350 g of ethylene glycol and 180 g of urea, stirring the mixed solution to be uniform, and then placing the solution in a 10 L stainless steel reaction kettle to react at 120°C for 24 hours, and then spray drying the mixed solution to obtain a powder of a cobalt-iron composite oxide;

[0041] S2, stirring 380 g of the sample powder with 2 L of tetraethyl orthosilicate and 1 L of tetraethyl orthosilicate and 2 L of ethanol for 2 hours, then adding 3.5 L of deionized water, and continuing to stir for 3 hours, then heating the mixed solution to 85°C at a rate of 2°C / min, and then continuing to stir at this temperature until the solution becomes a gel, to obtain a gel intermediate;

[0042] S3, drying the gel intermediate at 120°C for 12 hours, and then calcining at 900°C for 10 hours to obtain a silicon-containing iron-cobalt composite oxide;

[0043] S4, after crushing and sieving the silicon-containing iron-cobalt composite oxide into 120-mesh powder, adding 90 g of aluminum hydroxide sol and 50 g of silica sol, 110 g of sucrose and 100 ml of water, kneading for 2 hours, extruding into columnar samples, drying again at 120°C, and calcining at 600°C for 6 hours, a silicon oxide-coated iron-cobalt catalyst was obtained.

[0044] The present embodiment also provides an application of the silicon oxide-coated iron-cobalt catalyst in the synthesis of COS, which is specifically as follows:

[0045] After taking 20 ml of the above catalyst and sulfidizing at 450°C for 24 hours, CO gas and sulfur vapor were introduced to synthesize COS, and the space velocity of the catalyst was 400 h-1. -1 The concentration of the generated product COS reached 93.5%, and the concentration of COS after the catalyst was continuously used for 10 days was still greater than 90.0%, and the pulverization rate of the catalyst was less than 3.1%.

[0046] Example 4:

[0047] The present embodiment provides a preparation method of a sulfidized hydrodeoxygenation and isomerization catalyst, which comprises the following steps:

[0048] S1, 10 g of iron ammonium citrate and 40 g of cobalt chloride were dissolved in 1000 ml of deionized water, 20 g of ethylene glycol and 10 g of urea were added, and the mixed solution was stirred and mixed uniformly, then the mixed solution was placed in a 1.5L stainless steel reaction kettle and reacted at 150°C for 4 hours, and then the mixed solution was spray dried to obtain iron-cobalt composite oxide powder;

[0049] S2, 80 g of iron-cobalt composite oxide powder was fully stirred with 200 ml of tetraethyl orthosilicate and 400 ml of ethanol for 1 hour, then 750 ml of deionized water was added, and stirring was continued for 2 hours, then the mixed solution was heated to 80°C at a rate of 2°C / min, and then the temperature was kept constant at this temperature, and stirring was continued until the solution became a gel, and a gel intermediate was obtained;

[0050] S3, the gel intermediate was dried at 120°C for 12 hours, and then calcined at 900°C for 4 hours to obtain silicon-containing iron-cobalt composite oxide;

[0051] S4, after crushing and sieving the silicon-containing iron-cobalt composite oxide into 120-mesh powder, adding 90 g of aluminum hydroxide sol and 50 g of silica sol, 110 g of sucrose and 100 ml of water, kneading for 2 hours, extruding into columnar samples, drying again at 120°C, and calcining at 600°C for 6 hours, a silicon oxide-coated iron-cobalt catalyst was obtained.

[0052] Example 5:

[0053] This embodiment provides a method for preparing a sulfide-state hydrodeoxygenation and isomerization catalyst, including the following steps:

[0054] S1. Dissolve 50g of ferric ammonium citrate and 10g of cobalt chloride in 500ml of deionized water, add 10g of ethylene glycol and 50g of urea, stir and mix the solution evenly, place it in a 1L stainless steel reactor and react at 150℃ for 4 hours, then spray dry the above mixture to obtain iron-cobalt composite oxide powder.

[0055] S2. After stirring 75g of iron-cobalt composite oxide powder with 200ml of tetraethyl orthosilicate and 500ml of ethanol for 1 hour, add 750ml of deionized water and continue stirring for 2 hours. Then, heat the mixed solution to 80℃ at a rate of 2℃ / min, and then keep it at this temperature and continue stirring until the solution becomes gel-like to obtain a gel intermediate.

[0056] S3. The gel intermediate was dried at 120°C for 12 hours and then calcined at 900°C for 4 hours to obtain silicon-containing iron-cobalt composite oxide.

[0057] S4. After crushing and sieving the silicon-containing iron-cobalt composite oxide into 200-mesh powder, add 30g of aluminum hydroxide sol, 35g of asphalt powder and 20ml of water and knead for 5 hours. Then, extrude it into a columnar sample, dry it again at 150℃, and calcine it at 600℃ for 4 hours to obtain the silicon oxide-cobalt catalyst.

[0058] The table below compares the performance of commercially available catalysts with that of Examples 1-3 of this application.

[0059] Catalyst performance comparison table

[0060] No. CO conversion COS yield Catalyst shape Average dusting rate per 10 days Commercial sample 1 ～98.8％ ～80％ Strip 25.5％ Commercial sample 2 ～98.7％ ～64％ Spherical 21.5％ Example 1 sample ～98.5％ ～93.2％ Columnar 2.8％ Example 2 sample ～98.4％ ～92.6％ Columnar 3.7％ Example 3 sample ～98.6％ ～93.5％ Columnar 3.1％

[0061] In summary, the method for preparing a silica-encapsulated iron-cobalt catalyst provided by this invention produces a catalyst with strong anti-pulverization properties for the synthesis of COS. Compared with existing commercial catalysts, it features a long service life, high mechanical strength, low loss rate, and strong anti-pulverization ability. In the dry COS preparation reaction, it exhibits high CO conversion rate and good selectivity for the COS product.

[0062] Any aspects not described in this invention are applicable to existing technologies.

[0063] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a silicon oxide-coated iron-cobalt catalyst, characterized by, The method comprises the following steps: S1, dissolving ferric ammonium citrate and cobalt chloride in deionized water, adding ethylene glycol and urea, stirring the mixed solution to be uniform, and then reacting at 120-180℃ for 2-24 hours, and then spray drying the mixture to obtain a powder of iron-cobalt composite oxide; wherein the mass ratio of ferric ammonium citrate, cobalt chloride, deionized water, ethylene glycol and urea is (1-5):(1-4):(50-100):(1-2):(1-5); S2, mixing the iron-cobalt composite oxide powder with organosilicate and solvent and stirring for 1 hour, then adding deionized water and continuing to stir for 2 hours, then heating the mixed solution to 80-90℃ at a rate of 2℃ / min and keeping the temperature constant, and continuing to stir until the solution becomes a gel, to obtain a gel intermediate; S3, drying the gel intermediate at 120-150℃ for 12 hours, and then calcining at 700-900℃ for 4-10 hours to obtain a silicon-containing iron-cobalt composite oxide; S4, crushing the silicon-containing iron-cobalt composite oxide into a powder with a particle size of 120-200 mesh, adding a binder, a pore-forming agent and deionized water, kneading for 2-6 hours, extruding into a strip, and then drying and calcining to obtain the desired silicon-coated iron catalyst; wherein the binder is one or more of silica solution, aluminum hydroxide sol solution, and carboxymethyl cellulose sodium solution; the pore-forming agent is one or more of asphalt, starch, sucrose and phenolic resin.

2. The production method according to claim 1, characterized by, The mass-volume ratio of the iron-cobalt composite oxide powder, organosilicate and solvent added in step S2 is (75-80)g:200ml:(400-500)ml.

3. The preparation method according to claim 1, characterized in that, The organosilicate added in step S2 is one or more of tetraethyl orthosilicate, tetra-n-butyl orthosilicate, tetra-isopropyl orthosilicate and tetraethyl orthosilicate; the solvent added is one or more of ethanol, acetone, isopropyl alcohol and hexane.

4. The method of claim 1, wherein, The mass ratio of the silicon-containing iron-cobalt composite oxide powder, binder, pore-forming agent and deionized water added in step S4 is 100:(10-30):(15-35):

20.

5. The preparation method according to claim 1, characterized in that, The drying temperature in step S4 is 120-150℃, and the drying time is 8 hours; the calcination temperature is 600-700℃, and the calcination time is 4-6 hours.

6. A silicon-coated iron-cobalt catalyst prepared by the preparation method of any one of claims 1-5.

7. Use of the silicon oxide-coated iron cobalt catalyst according to claim 6 for the synthesis of COS, characterized in that, The catalyst is used for synthesizing COS reaction after being treated by sulfuration.