阅读说明：本技术 一种耐硫变换催化剂及其制备方法 (Sulfur-tolerant shift catalyst and preparation method thereof ) 是由 齐焕东 陈依屏 郭杰 王昊 姜建波 薛红霞 于 2018-09-06 设计创作，主要内容包括：本发明属于催化剂技术领域,具体涉及一种耐硫变换催化剂及其制备方法。所述催化剂,采用除碳镁铝尖晶石物料为主要载体成分,拟薄水铝石为助剂,拟薄水铝石的质量以Al<Sub>2</Sub>O<Sub>3</Sub>计,除碳镁铝尖晶石物料和Al<Sub>2</Sub>O<Sub>3</Sub>质量比为6.2：3.8～7.4：2.6；采用硝酸钴、钼酸铵为活性原料,硝酸钴质量以CoO计,钼酸铵质量以MoO<Sub>2</Sub>计,CoO质量占镁铝尖晶石与Al<Sub>2</Sub>O<Sub>3</Sub>质量之和的百分数为2.8％～3.5％,MoO<Sub>2</Sub>质量占镁铝尖晶石与Al<Sub>2</Sub>O<Sub>3</Sub>质量之和的百分数为7.8％～8.5％；采用田菁粉为造孔剂；采用柠檬酸为助挤剂。本发明制备的催化剂活性高,稳定性好；所述的制备方法,科学合理、简单易行。(The invention belongs to the technical field of catalysts, and particularly relates to a sulfur-tolerant shift catalyst and a preparation method thereof. The catalyst adopts decarbonized magnesia-alumina spinel material as a main carrier component, pseudo-boehmite as an auxiliary agent, and the quality of the pseudo-boehmite is Al 2 O 3 Metering, removing carbon, magnesium and aluminum spinel material and Al 2 O 3 The mass ratio is 6.2: 3.8-7.4: 2.6; cobalt nitrate and ammonium molybdate are used as active raw materials, the mass of the cobalt nitrate is calculated by CoO, and the mass of the ammonium molybdate is calculated by MoO 2 The mass of CoO accounts for magnesium aluminate spinel and Al 2 O 3 The mass sum percentage is 2.8-3.5%, MoO 2 The mass of the magnesium aluminate spinel and Al 2 O 3 The mass sum percentage is 7.8-8.5%; sesbania powder is used as a pore-forming agent; citric acid is used as extrusion aid. The catalyst prepared by the invention has high activity and good stability; the preparation method is scientific, reasonable, simple and feasible.)

1. A sulfur tolerant shift catalyst characterized by: the decarbonized magnesia-alumina spinel material is used as a main carrier component, the pseudo-boehmite is used as an auxiliary agent, and the quality of the pseudo-boehmite is Al₂O₃Metering, removing carbon, magnesium and aluminum spinel material and Al₂O₃The mass ratio is 6.2: 3.8-7.4: 2.6; cobalt nitrate and ammonium molybdate are used as active raw materials, the mass of the cobalt nitrate is calculated by CoO, and the mass of the ammonium molybdate is calculated by MoO₂The CoO accounts for the removal of carbon, magnesium and aluminum spinel and Al₂O₃The mass sum percentage is 2.8-3.5%, MoO₂The mass of the carbon-magnesium-aluminum spinel is removed₂O₃The mass sum percentage is 7.8-8.5%; sesbania powder is used as a pore-forming agent, and the mass of the sesbania powder is 3-5% of that of the carrier; citric acid is adopted as an extrusion aid, and the mass of the extrusion aid is 3-5% of that of the carrier;

the preparation method of the decarbonized magnesia-alumina spinel material comprises the following steps:

1) dissolving magnesium acetate in deionized water to prepare a magnesium acetate solution;

2) adding pseudo-boehmite powder into deionized water to prepare pseudo-boehmite water slurry;

3) pouring the magnesium solution into the pseudo-boehmite water slurry, adding ethylene glycol, keeping the temperature and stirring, pouring out the solution, drying, and roasting at the roasting temperature of 500-550 ℃ for 1-3 h to obtain the magnesia-alumina spinel removed material.

2. The sulfur tolerant shift catalyst of claim 1, wherein: in step 1), the magnesium acetate and Al in the pseudo-boehmite₂O₃In a molar ratio of 1: 1-1: 1.2.

3. the sulfur tolerant shift catalyst of claim 1, wherein: in the step 1), when magnesium acetate is dissolved in deionized water, the mass of the dissolved magnesium acetate per 100g of the deionized water is 30-40 g.

4. The sulfur tolerant shift catalyst of claim 1, wherein: in the step 2), when the pseudo-boehmite powder is added into deionized water, the mass of the pseudo-boehmite dissolved in every 100g of the deionized water is 50-60 g.

5. The sulfur tolerant shift catalyst of claim 1, wherein: in the step 3), the mass of the added glycol is 8-10% of that of the magnesium acetate.

6. The sulfur tolerant shift catalyst of claim 1, wherein: in the step 3), the temperature of heat preservation and stirring is 40-60 ℃, and the stirring time is 1-3 h.

7. The sulfur tolerant shift catalyst of claim 1, wherein: in the step 3), the drying temperature is 100-120 ℃.

8. The sulfur tolerant shift catalyst of claim 1, wherein: in the step 3), the temperature is raised by adopting a program during roasting, and the temperature raising rate is 300 ℃/h at the stage of normal temperature to 315 ℃; the temperature rise rate in the stage from 315 ℃ to 415 ℃ is 100 ℃/h; the temperature rise rate is 300 ℃/h in the stage from 415 ℃ to 550 ℃, and the temperature is kept for 3 hours after the temperature rises to 550 ℃.

9. A method of preparing a sulfur tolerant shift catalyst as claimed in any one of claims 1 to 8, wherein: the method comprises the following steps:

(1) pouring the decarbonized magnesia-alumina spinel material and the pseudo-boehmite into a kneader, dissolving ammonium molybdate with water, pouring the ammonium molybdate into the kneader, kneading, taking out, drying and crushing the mixture to more than 200 meshes;

(2) pouring the material obtained in the step (1) into a kneader, dissolving cobalt nitrate by water, pouring the cobalt nitrate into the kneader, kneading, dissolving citric acid by water, pouring the mixture into the kneader, pouring sesbania powder, kneading and extruding;

(3) and (3) airing the extruded strips, and roasting for 2-3 h at 480-550 ℃ to obtain a catalyst finished product.

10. The method of preparing a sulfur tolerant shift catalyst according to claim 9, wherein: the method comprises the following steps:

(1) pouring the decarbonized magnesia-alumina spinel material and the pseudo-boehmite into a kneader, dissolving ammonium molybdate by using the mass of the decarbonized magnesia-alumina spinel material and the pseudo-boehmite and 30-40% of water, pouring the ammonium molybdate into the kneader, kneading for 20-30 minutes, taking out, drying and crushing to more than 200 meshes;

(2) pouring the material obtained in the step (1) into a kneader, dissolving cobalt nitrate by using water accounting for 25-30% of the sum of the mass of the decarbonized magnesia-alumina spinel material and the mass of the pseudo-boehmite, pouring the cobalt nitrate into the kneader, kneading for 5-10 minutes, dissolving citric acid by using water accounting for 5-10% of the sum of the mass of the decarbonized magnesia-alumina spinel material and the mass of the pseudo-boehmite, pouring the citric acid into the kneader, pouring sesbania powder into the kneader, kneading for 20-30 minutes, and extruding strips;

(3) and (3) airing the strips extruded in the step (2), and roasting for 2-3 h at 480-550 ℃ to obtain a catalyst finished product.

Technical Field

The invention belongs to the technical field of catalysts, and particularly relates to a sulfur-tolerant shift catalyst and a preparation method thereof.

Background

The magnesia-alumina spinel as a composite oxide has the advantages of magnesia and alumina, stable structure, high hydration resistance and no two oxides, so that the magnesia-alumina spinel powder with magnesia-alumina spinel phase is an excellent carrier component.

The sulfur tolerant shift catalyst is one kind of catalyst with Co and Mo as active components and Mg and Al as carrier and is used in preparing ammonia synthesis gas, carbonyl synthesis gas, hydrogen or city gas with coal, heavy oil or residual oil as material. In view of the excellent properties of magnesium aluminate spinel, it is also used in the field of sulfur-tolerant shift catalysts.

CN97121053 relates to a novel CO sulfur-tolerant shift catalyst and its preparation method, mixing three powders of magnesium, aluminum and titanium, adding molybdenum solution, kneading, drying and pulverizing, adding extrusion aid and peptizing agent, kneading and forming, drying and roasting, water-treating at room temperature, and roasting to obtain the catalyst, so that MgO and Al can be converted into the catalyst₂O₃Mainly existing in the form of magnesium aluminate spinel structure.

Patent CN201310398946 relates to a sulfur-resistant methanation catalyst and a preparation method thereof, wherein magnesium and aluminum raw materials are mixed, water is added for full mixing, drying and roasting are carried out to obtain magnesium-aluminum spinel master batch, the master batch is subjected to steam curing or quenching treatment and drying or drying and roasting to obtain magnesium-aluminum spinel, then the magnesium-aluminum spinel and carrier materials are kneaded, extruded and roasted to obtain a catalyst carrier, then the obtained carrier is impregnated with a cobalt-molybdenum mixed co-impregnation solution, and the catalyst is obtained through drying and roasting.

Patent CN200910229290 relates to a preparation method of a clean CO sulfur-tolerant shift catalyst, which comprises the steps of mixing a magnesium acetate aqueous solution with a pseudo-boehmite aqueous slurry, adding a titanium-containing auxiliary agent, stirring, drying and roasting to obtain a magnesium-aluminum spinel basic material, then mixing the basic material, an aluminum powder material, the auxiliary agent and a pore-enlarging agent, pouring a magnesium solution, kneading and extruding to obtain a carrier, then impregnating with a cobalt-molybdenum complex solution, drying and roasting to obtain the catalyst; or mixing the basic material, the aluminum powder material, the magnesium powder material, the auxiliary agent and the pore-enlarging agent, pouring the cobalt-molybdenum complex solution, kneading and extruding the mixture to obtain the catalyst.

In view of the application of magnesium aluminate spinel in the field of catalysis, the preparation of magnesium aluminate spinel is researched all over the world, and the specific surface area and the particle size of different preparation methods or raw materials are different. The preparation methods of the magnesium aluminate spinel are various, but nitrate ions are involved (which are not friendly to the environment) or the requirement on equipment is high.

The patent CN200910229290.6 discloses a method for preparing a clean CO sulfur-tolerant shift catalyst, which is environment-friendly and has low requirements on equipment. However, the magnesium acetate contains a large amount of carbon, and the carbon separated out after decomposition is difficult to completely burn out in the roasting process, remains in the finished product material, and can be observed to be slightly blackened, so that the service performance of the catalyst is influenced.

Disclosure of Invention

The invention aims to provide a sulfur-tolerant shift catalyst, which adopts an improved magnesia-alumina spinel material as a main carrier component and pseudo-boehmite as an auxiliary agent, can effectively improve the activity of the catalyst and has good stability; the invention also provides a preparation method of the composition, which is scientific, reasonable, simple and feasible.

The sulfur-tolerant shift catalyst adopts decarbonized magnesia-alumina spinel material as main carrier component, pseudoboehmite as assistant, and the quality of the pseudoboehmite is Al₂O₃Metering, removing carbon, magnesium and aluminum spinel material and Al₂O₃The mass ratio is 6.2: 3.8-7.4: 2.6; cobalt nitrate and ammonium molybdate are used as active raw materials, the mass of the cobalt nitrate is calculated by CoO, and the mass of the ammonium molybdate is calculated by MoO₂The mass of CoO accounts for magnesium aluminate spinel and Al₂O₃The mass sum percentage is 2.8-3.5%, MoO₂The mass of the magnesium aluminate spinel and Al₂O₃Sum of massThe percentage of (A) is 7.8% -8.5%; sesbania powder is used as a pore-forming agent, and the mass of the sesbania powder is 3-5% of that of the carrier; citric acid is adopted as an extrusion aid, and the mass of the extrusion aid is 3-5% of that of the carrier;

the preparation method of the decarbonized magnesia-alumina spinel material comprises the following steps:

1) dissolving magnesium acetate in deionized water to prepare a magnesium acetate solution;

2) adding pseudo-boehmite powder into deionized water to prepare pseudo-boehmite water slurry;

3) pouring the magnesium solution into the pseudo-boehmite slurry, adding ethylene glycol, keeping the temperature and stirring, pouring out the solution, drying, and roasting at the roasting temperature of 500-550 ℃ for 1-3 h to obtain the magnesia-alumina spinel removed material;

wherein:

in step 1), the magnesium acetate and Al in the pseudo-boehmite₂O₃In a molar ratio of 1: 1-1: 1.2.

in the step 1), when magnesium acetate is dissolved in deionized water, the mass of the dissolved magnesium acetate per 100g of the deionized water is 30-40 g.

In the step 2), when the pseudo-boehmite powder is added into deionized water, the mass of the pseudo-boehmite dissolved in every 100g of the deionized water is 50-60 g.

In the step 3), the mass of the added glycol is 8-10% of that of the magnesium acetate.

In the step 3), the temperature of heat preservation and stirring is 40-60 ℃, and the stirring time is 1-3 h.

In the step 3), the drying temperature is 100-120 ℃.

In the step 3), the temperature is raised by adopting a program during roasting, and the temperature raising rate is 300 ℃/h at the stage of normal temperature to 315 ℃; the temperature rise rate in the stage from 315 ℃ to 415 ℃ is 100 ℃/h; the temperature rise rate is 300 ℃/h in the stage from 415 ℃ to 550 ℃, and the temperature is kept for 3 hours after the temperature rises to 550 ℃.

The preparation method of the sulfur-tolerant shift catalyst comprises the following steps:

(1) pouring the decarbonized magnesia-alumina spinel material and the pseudo-boehmite into a kneader, dissolving ammonium molybdate with water, pouring the ammonium molybdate into the kneader, kneading, taking out, drying and crushing the mixture to more than 200 meshes;

(2) pouring the material obtained in the step (1) into a kneader, dissolving cobalt nitrate by water, pouring the cobalt nitrate into the kneader, kneading, dissolving citric acid by water, pouring the mixture into the kneader, pouring sesbania powder, kneading and extruding;

(3) and (3) airing the extruded strips, and roasting for 2-3 h at 480-550 ℃ to obtain a catalyst finished product.

Preferably, the preparation method of the sulfur-tolerant shift catalyst comprises the following specific steps:

(1) pouring the decarbonized magnesia-alumina spinel material and the pseudo-boehmite into a kneader, dissolving ammonium molybdate by using the mass of the decarbonized magnesia-alumina spinel material and the pseudo-boehmite and 30-40% of water, pouring the ammonium molybdate into the kneader, kneading for 20-30 minutes, taking out, drying and crushing to more than 200 meshes;

(2) pouring the material obtained in the step (1) into a kneader, dissolving cobalt nitrate by using water accounting for 25-30% of the sum of the mass of the decarbonized magnesia-alumina spinel material and the mass of the pseudo-boehmite, pouring the cobalt nitrate into the kneader, kneading for 5-10 minutes, dissolving citric acid by using water accounting for 5-10% of the sum of the mass of the decarbonized magnesia-alumina spinel material and the mass of the pseudo-boehmite, pouring the citric acid into the kneader, pouring sesbania powder into the kneader, kneading for 20-30 minutes, and extruding strips;

(3) and (3) airing the strips extruded in the step (2), and roasting for 2-3 h at 480-550 ℃ to obtain a catalyst finished product.

The invention has the following beneficial effects:

1. the sulfur-resistant shift catalyst prepared by the method has higher activity than that of the sulfur-resistant shift catalyst prepared by the common magnesia-alumina spinel material, is superior to an industrial catalyst and has good stability.

2. The preparation method is scientific, reasonable, simple and feasible.

Detailed Description

The present invention is further described below with reference to examples.