A high-pressure sulfur-tolerant shift catalyst promoter complex and catalyst thereof

Abstract

The present application discloses a kind of high-pressure sulfur-tolerant shift catalyst additive complex, catalyst and preparation method, specifically discloses a kind of under the conditions of high-pressure pulverized coal gasification low water-gas ratio sulfur-tolerant process shift, inhibit methanation reaction additive complex, and the catalyst of adding the additive complex.Inhibit methanation reaction additive includes one or more of Mn, Zr, Cu, Fe and Cr oxide, nitrate, sulfate or carbonate, the prepared catalyst has excellent CO conversion activity in addition, also has excellent anti-methanation side reaction function.Suitable for high-pressure pulverized coal gasification high CO content low water-gas ratio process condition CO sulfur-tolerant conversion device, under high pressure and low water / gas conditions, can inhibit methanation side reaction, make methane generation amount significantly reduce, prevent shift furnace because of methanation side reaction and "fly temperature", stabilize shift operation, meet the needs of coal chemical industry high-pressure pulverized coal gasification new process development.

Description

Technical Field

[0001] This invention relates to an additive complex for suppressing methanation side reactions under high-pressure pulverized coal gasification low water-to-gas ratio sulfur-resistant shift conversion process conditions, a sulfur-resistant shift conversion catalyst, and a preparation method thereof. Specifically, it relates to a sulfur-resistant shift conversion catalyst for reducing methane content under high-pressure pulverized coal gasification shift conversion process conditions and its preparation method thereof. Background Technology

[0002] Methanation is a method of producing methane by hydrogenating CO or CO2 with a catalyst, but it is a side reaction of the CO conversion process. The specific reaction equation is as follows:

[0003]

[0004] Because this reaction is strongly exothermic, every 1% of CH4 generated will cause a temperature rise of about 60-70°C in the bed, burning out the catalyst and equipment! Furthermore, the higher the pressure and CO content, and the lower the water / gas ratio, the easier it is for the methanation side reaction to occur.

[0005] Pulverized coal gasification technology is favored by coal chemical users due to its advantages such as low requirements for coal quality, high content of effective components (CO+H2 89%) in process gas, low consumption of raw coal and oxygen, and low environmental pollution. However, since the CO content in the produced feed gas is as high as 60% or more, how to avoid methanation side reaction in the first reactor, prevent overheating of the shift reactor, and stabilize the operation of the unit are the key issues for the production of high CO feed gas units.

[0006] Recently, with the continuous advancement of coal gasification technology, industrial plants have increasingly higher energy consumption requirements. The pressure of pulverized coal gasification has increased from the original 4.0 MPa to 6.0 MPa and above. Since methanation is a volume-reducing reaction, the problem of methanation side reactions becomes even more prominent with increased pressure. It is essential to improve the catalyst's resistance to methanation side reactions to ensure the safe, stable, and long-term operation of high-pressure pulverized coal gasification process gas in coal chemical plants. Therefore, to adapt to the development needs of high-pressure (6.0 MPa and above) pulverized coal gasification technology, research on reducing methanation side reactions during CO shift reactions under high-pressure, high-CO content, and low water-to-gas ratio conditions, and to promote the long-term stable operation of sulfur-resistant shift converters, has become an urgent technical challenge.

[0007] This invention discovers an additive, which is then formulated into an additive complex to develop a catalyst that can significantly suppress methanation side reactions. This meets the needs of the development of new high-pressure pulverized coal gasification coal chemical processes and contributes to the promotion and application of clean and efficient coal gasification technologies in my country. Summary of the Invention

[0008] This invention discovers and identifies a novel additive for suppressing methanation side reactions under high-pressure pulverized coal gasification with low water / gas shift and sulfur-resistant process conditions, and develops a catalyst that can significantly suppress methanation side reactions, reducing the formation of methanation byproducts under high pressure and low water / gas conditions, thus meeting the needs of the chemical development of new coal gasification technologies. High pressure in this invention refers to a reaction pressure of 5.0 MPa and above, especially 6.0 MPa and above, and low water / gas refers to a water / gas ratio between 0.2 and 1.0, especially within the range of 0.3 to 0.6.

[0009] This invention claims a complex of additives for inhibiting methanation under high-pressure pulverized coal gasification low-water / gas-sulfur-resistant shift reaction conditions. The high pressure refers to a reaction pressure of 5.0 MPa or higher, and the low water / gas ratio is 0.3-0.8. The additives for inhibiting methanation are selected from oxides, nitrates, sulfates, or carbonates of Mn, Zr, Cu, Fe, and Cr. The additives for inhibiting methanation side reactions are mixed with one or more of boehmite, aluminum hydroxide, and alumina to form the additive complex. The content of the additives for inhibiting methanation in the additive complex, calculated as oxides, is 10-60%.

[0010] The additive composite is prepared by uniformly mixing the additive with one or more of boehmite, aluminum hydroxide, and alumina, kneading with a binder, and calcining to obtain the additive composite. The binder is one or more nitrates and / or sulfates of alkaline earth metals and alkali metals.

[0011] This invention also claims a catalyst for suppressing methanation side reactions under high-pressure pulverized coal gasification low-water / gas-sulfur-resistant shift reaction conditions, wherein the effective components of the catalyst are: cobalt (calculated as CoO) at 1-5% of the total catalyst amount, molybdenum (calculated as MoO3) at 3-15% of the total catalyst amount, and the above-prepared auxiliary compound is added.

[0012] The aforementioned additive complex is kneaded, extruded, and calcined with one or more of magnesium aluminum spinel, pseudoboehmite, and alumina, using a binder, to obtain a carrier. The active ingredients of the catalyst are then added. The additive complex is added at 10-80% by weight of the catalyst.

[0013] This invention also claims a method for preparing a catalyst that suppresses methanation side reactions under high-pressure pulverized coal gasification low-water / gas-sulfur-resistant shift reaction conditions, specifically comprising the following steps:

[0014] (1) Preparation of auxiliary agent complex;

[0015] (2) The additive complex is crushed and then kneaded, extruded and calcined with any one or more of magnesium aluminum spinel, pseudoboehmite and alumina, and a binder to obtain a carrier.

[0016] (3) Catalyst preparation by impregnation method: The support is impregnated with a co-impregnation solution containing the effective components of the catalyst, and then dried or calcined to obtain the catalyst.

[0017] In step (2), an adhesive is also added.

[0018] The binder is one or more nitrates and / or sulfates of alkaline earth metals and alkali metals, and the pore-forming agent is guar gum powder.

[0019] In step (2), the auxiliary compound is pulverized to 160-300 mesh, preferably to 180-200 mesh.

[0020] The technical effects achieved by this invention are as follows:

[0021] (1) A novel auxiliary agent for suppressing methanation side reaction was discovered, and a catalyst that can significantly suppress methanation side reaction was developed. In addition to having excellent CO conversion activity, the catalyst also has excellent anti-methanation side reaction function.

[0022] (2) Studies have found that when the interaction between CO and the catalyst is strong, the C–O bond tends to dissociate, thereby promoting the formation of C–H bonds and leading to the occurrence of methanation side reactions. The additive of the present invention can reduce the catalyst's adsorption capacity for CO, and the resulting catalyst can suppress methanation side reactions.

[0023] (3) When the catalyst prepared by the present invention is used under the conditions of high pressure pulverized coal gasification low water / gas sulfur-resistant conversion process, the amount of methane generated is significantly reduced, which can prevent the conversion furnace from "running over temperature" due to the methanation side reaction, stabilize the conversion operation, and realize the safe and long-term stable operation of the conversion device.

[0024] The catalyst prepared by this invention is suitable for use in high-pressure (6.0 MPa and above) pulverized coal gasification high CO content low water-gas ratio sulfur-resistant shift converters. It can suppress the occurrence of methanation side reactions and meet the needs of the development of new high-pressure pulverized coal gasification processes in coal chemical industry. Detailed Implementation

[0025] The present invention will now be further described with reference to the embodiments, but the scope of the present invention is not limited to the following embodiments.

[0026] The catalyst prepared in this invention is used in a high-pressure pulverized coal gasification low-water / gas-sulfur-resistant shift process at a pressure of 6.0 MPa and a space velocity of 2000 h⁻¹. -1 Under the conditions of water / gas ratio of 0.2, reaction temperature of 490℃, and raw gas composition of CO 67.17%, CO2 8.01%, H2S 0.35%, and H2 24.47%, a comparative test was conducted. The amount of methane generated was significantly reduced. The comparative evaluation results are shown in Table 1.

[0027] Example 1

[0028] 200g of boehmite and 20g of MnO were mixed evenly, kneaded with a 10% calcium nitrate solution, and calcined at 550℃ for 3 hours to obtain the additive composite. The additive composite was pulverized to 180 mesh. 40g of the additive composite powder was taken, and 100g of boehmite and 10g of guar gum powder were added. The mixture was kneaded with a 10% calcium nitrate solution, extruded into strips, and calcined at 550℃ for 2 hours to obtain the support. 100g of the support was mixed with 12g of ammonium tetramolybdate and 9g of cobalt nitrate to prepare a co-impregnation solution. An equal volume of the solution was used to impregnate the support, and the mixture was calcined at 450℃ for 2 hours to obtain the catalyst. The catalyst was designated JWH-1. The test results are shown in Table 1.

[0029] Example 2

[0030] The preparation method is the same as in Example 1, except that the amount of auxiliary agent MnO is increased from 20 g to 60 g, and the catalyst is designated JWH-2. The performance comparisons are shown in Table 1.

[0031] Example 3

[0032] The preparation method is the same as in Example 1, except that 20 grams of the auxiliary agent MnO is replaced with 20 grams of CuO, and the catalyst is designated JWH-3. The performance comparison is shown in Table 1.

[0033] Example 4

[0034] The preparation method is the same as in Example 3, except that the amount of CuO auxiliary agent is increased from 20 g to 60 g; the catalyst is designated JWH-4. Their performance comparisons are shown in Table 1.

[0035] Example 5

[0036] The preparation method is the same as in Example 4, except that 60 grams of CuO was replaced with 60 grams of Fe2O3, and the catalyst was designated JWH-5. The performance comparisons are shown in Table 1.

[0037] Example 6

[0038] The preparation method is the same as in Example 4, except that the 10% calcium nitrate solution is replaced with 10% magnesium nitrate for kneading, and the catalyst is designated JWH-6. Performance comparisons are shown in Table 1.

[0039] Example 7

[0040] The preparation method is the same as in Example 1, except that the amount of auxiliary compound material is reduced from 40 grams to 10 grams, and the catalyst is designated JWH-7. The performance comparisons are shown in Table 1.

[0041] Example 8

[0042] The preparation method is the same as in Example 1, except that the amount of the auxiliary compound material is increased from 40 grams to 70 grams, and the catalyst is designated JWH-8. The performance comparisons are shown in Table 1.

[0043] Comparative Example 1

[0044] A support was prepared by kneading 200g of boehmite and 10g of guar gum powder with a 10% calcium nitrate solution, extruding the mixture into strips, and calcining it at 550℃ for 2 hours. 100g of the support was then mixed with 12g of ammonium tetramolybdate and 9g of cobalt nitrate to form a co-impregnation solution. The solution was then applied to the support in an equal volume, and the mixture was calcined at 450℃ for 2 hours. The catalyst was designated as the control sample. The test results are shown in Table 1.

[0045] Table 1 Comparison of methane production by catalyst

[0046]

[0047] As shown in Table 1, the highest CH4 generation was 7.1% in the control sample without additives. CuO was the best additive in inhibiting the methanation reaction, with CH4 generation of only 0.6%. MnO was the least effective additive in inhibiting the methanation reaction, with CH4 generation of 4.6%.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for inhibiting methanation reaction under high-pressure pulverized coal gasification, low water-to-gas ratio, and sulfur-resistant shift reaction conditions, characterized in that, The catalyst contains the following active ingredients: cobalt (calculated as CoO) at 1-5% of the total catalyst volume, molybdenum (calculated as MoO3) at 3-15% of the total catalyst volume, and an additive complex. The additive complex is prepared by mixing an inhibitor of methanation reaction with one or more of the following additive carrier materials: boehmite, aluminum hydroxide, and alumina, kneading with a binder, and calcining. The inhibitor of methanation reaction includes one or more of oxides, nitrates, sulfates, or carbonates of Mn and Cu. The content of the inhibitor of methanation reaction in the additive complex, calculated as oxides, is 10-60%. The additive complex is kneaded, extruded, and calcined with one or more of magnesium aluminum spinel, pseudoboehmite, and alumina to obtain a carrier. Then, the effective components cobalt and molybdenum in the catalyst are added.

2. The catalyst according to claim 1, characterized in that, The high pressure refers to a reaction pressure of 5.0 MPa or above, and the low water / gas ratio is 0.6-1.

0.

3. The catalyst according to claim 1, characterized in that, The binder is one or more nitrates and / or sulfates of alkaline earth metals and alkali metals.

4. The catalyst according to claim 1, characterized in that, The amount of the additive complex added accounts for 10-50% by weight of the catalyst.

5. A method for preparing the catalyst according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Preparation of auxiliary agent complex; (2) The additive complex is crushed and then kneaded with one or more of magnesium aluminum spinel, pseudoboehmite and alumina, along with a pore-forming agent and a binder, extruded and calcined to obtain a carrier. (3) Catalyst preparation by impregnation method: The support is impregnated with a co-impregnation solution containing the effective components of the catalyst, and then dried or calcined to obtain the catalyst.

6. The method for preparing the catalyst according to claim 5, characterized in that, The binder is one or more nitrates and / or sulfates of alkaline earth metals and alkali metals, and the pore-forming agent is guar gum powder.

7. The method for preparing the catalyst according to claim 5, characterized in that, In step (2), the auxiliary compound is pulverized to 160-300 mesh.

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