A copper-based carbon monoxide isothermal shift catalyst and a method for preparing the same

Abstract

The present application belongs to the technical field of catalysts, and particularly relates to a copper-based carbon monoxide isothermal shift catalyst for generating carbon dioxide and hydrogen from carbon monoxide and steam and a preparation method thereof. The catalyst composition comprises the following components in percentage by weight: copper oxide 35-50%, zinc oxide 25-40%, aluminum oxide 5-15%, structural additive oxide 2-10%, and modified additive oxide 1-5%. The catalyst prepared by the preparation method provided by the present application introduces modified additives and structural additives on the basis of Cu, Zn and Al, the structural additive metal and Al play a double carrier role, the heat transfer performance of the catalyst is enhanced, the modified additive and the active component Cu play a synergistic catalytic role, the performance of the catalyst is improved, the occurrence of side reactions is inhibited, and the generation amount of alcohol in the liquid phase product is reduced.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a carbon monoxide isothermal conversion catalyst for the reaction of carbon monoxide with water vapor to produce carbon dioxide and hydrogen, and its preparation method. Background Technology

[0002] Carbon monoxide shift (CO conversion) is an important component of modern coal chemical projects. It converts CO in feed gas into H2 through a shift reaction, adjusting the hydrogen-to-carbon ratio to meet the requirements of downstream units. The shift reaction is a reversible exothermic reaction. Traditional shift technologies typically employ multiple adiabatic shift reactors in series to achieve the desired shift depth. With the continuous development of coal gasification technology, dry pulverized coal quenching gasification technology has been widely applied. This type of gasification technology produces crude coal gas with high water and high CO content—a "double high" characteristic. If directly fed into the shift reactor, the catalyst bed temperature can reach over 500℃, severely impacting catalyst lifespan and system safety. Traditional adiabatic shift technologies generally employ high or low water-to-gas ratio processes to prevent catalyst bed overheating. However, neither high nor low water-to-gas ratio processes fundamentally solve the problem of catalyst operation at high temperatures. In recent years, isothermal shift technology has received significant attention from numerous research institutions and enterprises, achieving breakthrough developments and fundamentally solving the problem of catalyst bed overheating in "double high" crude coal gas shift reactions. Catalysts are key to achieving advanced processes, and the selection of reactors has a great influence on the optimal activity and lifespan of catalysts. Only by combining the two organically can energy conservation and consumption reduction be achieved and optimal process indicators be realized.

[0003] The catalysts currently used with isothermal reactors have two main problems. First, their performance in the high-temperature zone is relatively low. When the temperature is above 280℃, the CO conversion rate shows a significant downward trend. Second, there are many side reactions. The content of alcohols in the liquid (aqueous) products of the reaction increases significantly with the increase of reaction temperature, which increases the subsequent separation cost. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a copper-based carbon monoxide isothermal conversion catalyst with excellent performance in the high-temperature region and few side reactions.

[0005] To achieve the above objectives, the first aspect of the present invention provides a copper-based carbon monoxide isothermal conversion catalyst, wherein the catalyst composition includes the following components by weight percentage: copper oxide 35-50%, zinc oxide 25-40%, aluminum oxide 5-15%, structural auxiliary oxide 2-10%, and modified auxiliary oxide 1-5%.

[0006] The catalyst provided by this invention has a structural auxiliary metal selected from at least one of cerium, zirconium, calcium, magnesium, iron, and manganese, and a corresponding auxiliary salt selected from at least one of its corresponding nitrate and carbonate. The modifying auxiliary metal is selected from at least one of lithium, sodium, potassium, rubidium, and cesium, and a corresponding auxiliary salt selected from at least one of its corresponding acetate and hydroxide.

[0007] A second aspect of the present invention provides a method for preparing a copper-based carbon monoxide isothermal shift catalyst, comprising:

[0008] (1) Add sodium carbonate and deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two portions;

[0009] (2) Dissolve the structural aid metal salt in deionized water;

[0010] (3) Add the solution from step (2) to the zinc nitrate solution and mix well;

[0011] (4) Add the mixture from step (3) to the sodium carbonate solution from step (1) at a uniform rate to allow for precipitation and aging;

[0012] (5) Add copper nitrate solution to sodium carbonate solution (1) at a uniform rate to carry out precipitation and aging;

[0013] (6) Add the material obtained in step (4) to the material in step (5) and mix evenly;

[0014] (7) After the mixed materials are washed and settled 5 times, alumina powder is added and the mixture is pulped for 0.3-0.5 hours;

[0015] (8) After pulping, the material is filtered and dried;

[0016] (9) Dissolve the modified metal salt in deionized water;

[0017] (10) During the grinding process of the material obtained in (8), the solution obtained in (9) is sprayed into it;

[0018] (11) The material obtained in (10) is roasted and pressed into tablets.

[0019] In some embodiments of the present invention, preferably, the molar concentration of sodium carbonate solution in step (1) of the catalyst preparation method is 0.5-1.0 mol / L.

[0020] In some embodiments of the present invention, preferably, the precipitation temperature in step (4) of the catalyst preparation method is 65-67℃, the final pH value is 7.0-7.2, the aging temperature is 60-65℃, and the aging time is 0.4-0.8h.

[0021] In some embodiments of the present invention, preferably, the neutralization temperature in step (5) of the catalyst preparation method is 75-77°C, the endpoint pH value is 7.2-7.4, the aging temperature is 70-75°C, and the aging time is 0.4-0.8h.

[0022] In some embodiments of the present invention, preferably, the material mixing temperature in step (6) of the catalyst preparation method is 65-67°C and the mixing time is 0.3-0.5h.

[0023] In some embodiments of the present invention, preferably, the material roasting temperature in step (11) of the catalyst preparation method is 450-550℃ and the roasting time is 3-5h.

[0024] The third aspect of the present invention provides the application of the copper-based carbon monoxide isothermal shift catalyst provided by the present invention or the copper-based carbon monoxide isothermal shift catalyst prepared by the preparation method provided by the present invention in the carbon monoxide isothermal shift reaction.

[0025] This invention provides a carbon monoxide isothermal shift reaction, in which a feed gas is reacted with a carbon monoxide isothermal shift catalyst provided by this invention. The reaction conditions include: feed gas composition (v / v%): CO 20-25%, CO2 4-10%, H2 50-60%, CH4 5-15%; vapor-to-gas ratio (water vapor / dry gas molar ratio) 0.45; reaction pressure 3.0 MPa; and space velocity 2000 h⁻¹. -1 The inlet temperature is 280-300℃. The catalyst requires reduction before use. Activation conditions: reducing atmosphere N2 / H2 mixture (5% N2, balance H2); reduction pressure: 0.4-0.5 MPa; reduction space velocity 1000 h⁻¹. -1 The temperature is slowly increased to 230℃ and held for 2.0 hours (heating rate 1℃ / 3min).

[0026] CO conversion rate calculation formula:

[0027] E = ×100

[0028] Where: Φ1: CO volume fraction in the intake air (raw material gas), %

[0029] Φ2: CO volume fraction in the outgoing gas (product gas), %.

[0030] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0031] Through the above technical solution, the catalyst prepared by the method provided by the present invention introduces a modifying agent and a structural agent on the basis of Cu, Zn and Al. The structural agent metal and Al play a dual carrier role, which enhances the heat transfer performance of the catalyst. The modifying agent and the active component Cu play a synergistic catalytic role, which improves the performance of the catalyst, inhibits the occurrence of side reactions, and reduces the content of alcohols in the liquid phase. Detailed Implementation

[0032] The present invention will be described in detail below through examples. In the following examples, the catalyst composition was determined by calculation of the feed amount; the alcohol content in the liquid phase product was determined by analysis by liquid chromatography.

[0033] Example 1

[0034] (1) Add 212g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions of 2L each;

[0035] (2) Dissolve 20g of cerium nitrate in 100ml of deionized water;

[0036] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.38mol / L and mix well;

[0037] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.0, and the mixture is aged at 60℃ for 0.4h.

[0038] (5) Add 1.5L of copper nitrate solution with a molar concentration of 0.7mol / L to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 75℃, the final pH value is 7.2, and the solution is aged at 70℃ for 0.4h.

[0039] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.3 h.

[0040] (7) After the mixed material is washed and settled 5 times, 50g of alumina powder is added and the mixture is pulped for 0.5h.

[0041] (8) After pulping, the material is filtered and dried;

[0042] (9) Dissolve 3.5g of potassium hydroxide in 100mL of deionized water;

[0043] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0044] (11) After granulation of the material obtained in (10), it was calcined at 550℃ for 3.0h, and graphite was added to form tablets to obtain catalyst S-1. The analytical data are shown in Table 1 and Table 2 below.

[0045] Example 2

[0046] (1) Add 240g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0047] (2) Dissolve 15g of cerium nitrate and 15g of calcium nitrate in 100ml of deionized water;

[0048] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.45mol / L, and mix thoroughly;

[0049] (4) The mixture from step (3) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 67℃, the final pH value was 7.1, and the mixture was aged at 65℃ for 0.5h.

[0050] (5) 1.5L of copper nitrate with a molar concentration of 0.8mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.2, and the solution was aged at 72℃ for 0.6h.

[0051] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.4 h.

[0052] (7) After the mixed material is washed and settled 5 times, 60g of alumina powder is added and the mixture is pulped for 0.4h.

[0053] (8) After pulping, the material is filtered and dried;

[0054] (9) Dissolve 3g of potassium hydroxide and 2g of lithium hydroxide in 100mL of deionized water;

[0055] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0056] (11) After granulation of the material obtained in (10), it was calcined at 550℃ for 3.0h, and graphite was added to form tablets to obtain catalyst S-2. The analytical data are shown in Table 1 and Table 2 below.

[0057] Example 3

[0058] (1) Add 260g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0059] (2) Dissolve 15g of calcium nitrate and 10g of magnesium nitrate in 100ml of deionized water;

[0060] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.40mol / L, and mix thoroughly;

[0061] (4) The mixture from step (3) was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 67℃, the final pH value was 7.2, and the mixture was aged at 65℃ for 0.6h.

[0062] (5) 1.5L of copper nitrate with a molar concentration of 0.75mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the solution was aged at 72℃ for 0.7h.

[0063] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.6 h.

[0064] (7) After the mixed material is washed and settled 5 times, 45g of alumina powder is added and the mixture is pulped for 0.5h.

[0065] (8) After pulping, the material is filtered and dried;

[0066] (9) Dissolve 4g of rubidium hydroxide in 100mL of deionized water;

[0067] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0068] (11) After granulation of the material obtained in (10), it was calcined at 500℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-3. The analytical data are shown in Table 1 and Table 2 below.

[0069] Example 4

[0070] (1) Add 260g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0071] (2) Dissolve 15g of calcium nitrate and 10g of magnesium nitrate in 100ml of deionized water;

[0072] (3) Add 1.52 L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.40 mol / L, and mix thoroughly;

[0073] (4) The mixture from step (3) was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 67℃, the final pH value was 7.2, and the mixture was aged at 65℃ for 0.6h.

[0074] (5) 1.5L of copper nitrate with a molar concentration of 0.75mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 77℃, the final pH value was 7.3, and the solution was aged at 72℃ for 0.7h.

[0075] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.6 h.

[0076] (7) After the mixed material is washed and settled 5 times, 45g of alumina powder is added and the mixture is pulped for 0.5h.

[0077] (8) After pulping, the material is filtered and dried;

[0078] (9) Dissolve 4g of chromium nitrate in 100mL of deionized water;

[0079] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0080] (11) After granulation of the material obtained in (10), it was calcined at 500℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-4. The analytical data are shown in Table 1 and Table 2 below.

[0081] Example 5

[0082] (1) Add 230g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0083] (2) Dissolve 25g of zirconium nitrate in 100ml of deionized water;

[0084] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.50mol / L, and mix thoroughly;

[0085] (4) The mixture from step (3) was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 67℃, the final pH value was 7.1, and the mixture was aged at 62℃ for 0.8h.

[0086] (5) 1.5L of copper nitrate with a molar concentration of 0.85mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 77℃, the final pH value was 7.4, and the solution was aged at 70℃ for 0.8h.

[0087] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.5 h.

[0088] (7) After the mixed material is washed and settled 5 times, 40g of alumina powder is added and the mixture is pulped for 0.3h;

[0089] (8) After pulping, the material is filtered and dried;

[0090] (9) Dissolve 5g of sodium hydroxide in 100mL of deionized water;

[0091] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0092] (11) After granulation of the material obtained in (10), it was calcined at 480℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-5. The analytical data are shown in Table 1 and Table 2 below.

[0093] Example 6

[0094] (1) Add 240g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0095] (2) Dissolve 15g of zirconium nitrate and 10g of manganese magnesium nitrate in 100ml of deionized water;

[0096] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.55mol / L, and mix thoroughly;

[0097] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.0, and the mixture is aged at 65℃ for 0.5h.

[0098] (5) 1.5L of copper nitrate with a molar concentration of 0.7mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the solution was aged at 70℃ for 0.6h.

[0099] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.5 h.

[0100] (7) After the mixed material is washed and settled 5 times, 65g of alumina powder is added and the mixture is pulped for 0.6h;

[0101] (8) After pulping, the material is filtered and dried;

[0102] (9) Dissolve 8g of potassium acetate in 100mL of deionized water;

[0103] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0104] (11) After granulation of the material obtained in (10), it was calcined at 500℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-6. The analytical data are shown in Table 1 and Table 2 below.

[0105] Example 7

[0106] (1) Add 260g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0107] (2) Dissolve 25g of cerium carbonate in 100ml of deionized water;

[0108] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.40mol / L, and mix thoroughly;

[0109] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.2, and the mixture is aged at 65℃ for 0.6h.

[0110] (5) 1.5L of copper nitrate with a molar concentration of 0.7mol / L was added to 2L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 77℃, the final pH value was 7.3, and the solution was aged at 72℃ for 0.7h.

[0111] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.6 h.

[0112] (7) After the mixed material is washed and settled 5 times, 60g of alumina powder is added and the mixture is pulped for 0.5h.

[0113] (8) After pulping, the material is filtered and dried;

[0114] (9) Dissolve 6g of sodium acetate in 100mL of deionized water;

[0115] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0116] (11) After granulation of the material obtained in (10), it was calcined at 520℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-7. The analytical data are shown in Table 1 and Table 2 below.

[0117] Example 8

[0118] (1) Add 250g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0119] (2) Dissolve 15g of zirconium carbonate and 10g of magnesium carbonate in 100ml of deionized water;

[0120] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.45mol / L, and mix thoroughly;

[0121] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.2, and the mixture is aged at 65℃ for 0.6h.

[0122] (5) 1.55 L of copper nitrate with a molar concentration of 0.7 mol / L was added to 2 L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75 °C, the final pH value was 7.3, and the solution was aged at 73 °C for 0.6 h.

[0123] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.6 h.

[0124] (7) After the mixed material is washed and settled 5 times, 35g of alumina powder is added and the mixture is pulped for 0.6h;

[0125] (8) After pulping, the material is filtered and dried;

[0126] (9) Dissolve 5g of sodium acetate and 2g of potassium hydroxide in 100mL of deionized water;

[0127] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0128] (11) After granulation of the material obtained in (10), it was calcined at 520℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-8. The analytical data are shown in Table 1 and Table 2 below.

[0129] Example 9

[0130] (1) Add 280g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0131] (2) Dissolve 15g of cerium carbonate and 10g of magnesium nitrate in 100ml of deionized water;

[0132] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.5mol / L, and mix thoroughly;

[0133] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.1, and the mixture is aged at 65℃ for 0.7h.

[0134] (5) 1.55 L of copper nitrate with a molar concentration of 0.6 mol / L was added to 2 L of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the solution was aged at 72℃ for 0.7 h.

[0135] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.6 h.

[0136] (7) After the mixed material is washed and settled 5 times, 70g of alumina powder is added and the mixture is pulped for 0.6h;

[0137] (8) After pulping, the material is filtered and dried;

[0138] (9) Dissolve 3g of sodium acetate and 4g of potassium hydroxide in 100mL of deionized water;

[0139] (10) Spray the solution obtained in (9) into the material during the grinding process;

[0140] (11) After granulation of the material obtained in (10), it was calcined at 470℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-8. The analytical data are shown in Table 1 and Table 2 below.

[0141] Comparative Example 1 (Example 1 without added structural additives)

[0142] (1) Add 200g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0143] (2) 1.5L of zinc nitrate solution with a molar concentration of 0.385mol / L was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 65℃, the final pH value was 7.0, and the solution was aged at 60℃ for 0.4h.

[0144] (3) 1.5 L of copper nitrate solution with a molar concentration of 0.7 mol / L was added to 2 mL of sodium carbonate solution at a constant rate to carry out precipitation. The precipitation temperature was 75 °C and the final pH value was 7.2. The solution was then aged at 70 °C for 0.4 h.

[0145] (4) At a temperature of 65°C, add the material obtained in step (2) to the material in step (3) and mix for 0.3 hours.

[0146] (5) After the mixed material is washed and settled 5 times, 50g of alumina powder is added and the mixture is slurried for 0.5h.

[0147] (6) After pulping, the material is filtered and dried;

[0148] (7) Dissolve 3.5g of potassium hydroxide in 100mL of deionized water;

[0149] (8) Spray the solution obtained in (7) into the material during the grinding process;

[0150] (9) After granulation of the material obtained in (8), it was calcined at 500℃ for 4.0h, and graphite was added to form tablets to obtain catalyst D-1. The analytical data are shown in Table 1 and Table 2 below.

[0151] After grinding and granulation, the material was calcined at 550℃ for 3.0 h, and then graphite was added and pressed into tablets to obtain catalyst D-1. The analytical data are shown in Tables 1 and 2 below.

[0152] Comparative Example 2 (Example 1 without added modifiers)

[0153] (1) Add 200g of sodium carbonate and 4L of deionized water to a reactor equipped with a stirring paddle and water bath heating, stir evenly, and divide into two equal portions, each 2L;

[0154] (2) Dissolve 20g of cerium nitrate in 100ml of deionized water;

[0155] (3) Add 1.5L of the solution from step (2) to a zinc nitrate solution with a molar concentration of 0.385mol / L and mix thoroughly;

[0156] (4) The mixture from step (3) is added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 65℃, the final pH value is 7.0, and the mixture is aged at 60℃ for 0.4h.

[0157] (5) Add 1.5L of copper nitrate solution with a molar concentration of 0.7mol / L to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature is 75℃, the final pH value is 7.2, and the solution is aged at 70℃ for 0.4h.

[0158] (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (5) and mix for 0.3 h.

[0159] (7) After the mixed material is washed and settled 5 times, 50g of alumina powder is added and the mixture is pulped for 0.5h.

[0160] (8) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 550℃ for 3.5h, and graphite was added to form tablets to obtain catalyst D-2. The analytical data are shown in Tables 1 and 2 below.

[0161] Comparative Example 3

[0162] Prepared according to Example 1 of patent CN 101786000 A.

[0163] The copper and zinc solutions in the comparative example were precipitated with sodium carbonate solution under the same conditions as the comparative example. The precipitation process...

[0164] In the process, an equal amount of Al(NO3)3 solution was added for co-precipitation. After aging, the precipitated product was washed to remove impurity ions. Then, 40g of gallium oxide monohydrate was added while stirring. After aging at 60℃ for 0.5h, it was calcined at 400℃ for 2h. Finally, graphite, a molding aid, was added and pressed into tablets with a diameter of φ5×4.5-5mm to obtain comparative example D-3.

[0165] Table 1 Comparison of data from the examples and comparative examples.

[0166] catalyst Inlet temperature / °C CO content in raw gas / % CO conversion rate / % Alcohol content / ppm S-1 280 22 93.5 1500 S-2 280 22 93.0 1350 S-3 280 22 93.6 1480 S-4 280 22 92.7 1550 S-5 280 22 92.5 1450 S-6 280 22 93.0 1400 S-7 280 22 93.1 1520 S-8 280 22 92.8 1490 S-9 280 22 92.6 1510 D-1 280 22 87.5 1650 D-2 280 22 92.6 2200 D-3 280 22 85.5 2650

[0167] Table 2 Comparison of data from the examples and comparative examples

[0168] catalyst Inlet temperature / °C CO content in raw gas / % CO conversion rate / % Alcohol content / ppm S-1 300 20 92.5 1700 S-2 300 20 92.0 1650 S-3 300 20 92.6 1660 S-4 300 20 92.2 1650 S-5 300 20 92.0 1690 S-6 300 20 91.9 1590 S-7 300 20 92.1 1620 S-8 300 20 91.8 1690 S-9 300 20 91.9 1610 D-1 300 20 86.5 1820 D-2 300 20 91.6 2600 D-3 300 20 83.5 3100

[0169] As can be seen from the data in Tables 1 and 2, the catalyst prepared using this invention exhibits excellent performance. The addition of structural promoters can significantly improve the CO conversion rate of strong catalysts, and the addition of modified promoters can suppress side reactions and effectively reduce the amount of alcohols generated in the liquid phase products of the shift reaction. Furthermore, it can be seen that the catalyst prepared using this invention has superior performance compared to catalysts prepared using processes described in other patents.

[0170] The present invention and its embodiments have been described above illustratively. This description is not restrictive. Therefore, if those skilled in the art are inspired by it and design similar solutions and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. Use of a copper-based catalyst in the isothermal shift conversion of carbon monoxide, characterized in that The raw gas is catalytically reacted with a copper-based carbon monoxide isothermal shift catalyst, the reaction conditions are as follows: the gas composition of the raw gas is as follows in terms of volume percentage: CO 20-25%, CO24-10%, H2 50-60%, CH4 5-15%, the molar ratio of water vapor to dry gas is 0.45, the reaction pressure is 3.0 MPa, the space velocity is 2000h -1 , the inlet temperature is 280-300 DEG C; the catalyst comprises the following components in terms of weight percentage: copper oxide 35-50%, zinc oxide 25-40%, aluminum oxide 5-15%, structural additive metal oxide 2-10%, modified additive metal oxide 1-5%; the structural additive metal is at least one of cerium, zirconium, calcium, magnesium, iron, manganese and chromium; the modified additive metal is at least one of lithium, sodium, potassium, rubidium and cesium; The preparation method of the catalyst comprises the following steps: (1) adding sodium carbonate and deionized water into a reactor with stirring paddle and water bath heating, stirring uniformly, and dividing into two parts; (2) dissolving structural auxiliary metal salt in deionized water; (3) adding the solution in step (2) into the solution of zinc nitrate, and mixing uniformly; (4) adding the mixture in step (3) into the sodium carbonate solution in (1) at a uniform speed to carry out precipitation and aging; (5) adding copper nitrate solution into the sodium carbonate solution in (1) at a uniform speed to carry out precipitation and aging; (6) adding the material obtained in step (4) into the material in step (5), and mixing uniformly; (7) after mixing, the material is washed by sedimentation, and alumina powder is added to beat the pulp for 0.3-0.5h; (8) after beating the pulp, the material is filtered and dried; (9) dissolving modified auxiliary metal salt in deionized water; (10) spraying the solution obtained in step (9) into the material obtained in step (8) during the grinding process; (11) calcining the material obtained in step (10) and pressing into tablets.

2. Use according to claim 1, characterized in that The molar concentration of the sodium carbonate solution in step (1) is 0.5-1.0mol / L.

3. Use according to claim 1, characterized in that The structural auxiliary salt in step (2) is at least one of the nitrate salt, carbonate salt corresponding to the metal thereof; the modified auxiliary salt in step (9) is at least one of the acetate salt, nitrate salt, hydroxide corresponding to the metal thereof.

4. Use according to claim 1, characterized in that The precipitation temperature in step (4) is 65-67℃, the end point pH value is 7.0-7.2, the aging temperature is 60-65℃, and the aging time is 0.4-0.8h.

5. The use according to claim 1, characterized in that The precipitation temperature in step (5) is 75-77℃, the end point pH value is 7.2-7.4, the aging temperature is 70-75℃, and the aging time is 0.4-0.8h.

6. Use according to claim 1, characterized in that The material mixing temperature in step (7) is 65-67℃, and the mixing time is 0.3-0.5h.

7. Use according to claim 1, characterized in that The material calcination temperature in step (11) is 450-550℃, and the calcination time is 3-5h.