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

Abstract

The application discloses a copper-based carbon monoxide isothermal conversion catalyst and a preparation method thereof; the catalyst is composed of the following components in percentage by weight: 35-50% of copper oxide, 25-40% of zinc oxide, 5-15% of aluminum oxide, 2-10% of structural additive oxide and 1-5% of modified additive oxide; the catalyst prepared by the preparation method has the modified additive and the structural additive introduced 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 catalysis role, the performance of the catalyst is improved, the occurrence of a side reaction is inhibited, and the generation amount of alcohol in a liquid phase product is reduced.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a copper-based carbon monoxide isothermal shift catalyst 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] 1. The technical problem to be solved: To address the aforementioned technical problems, this invention provides a copper-based carbon monoxide isothermal shift catalyst and its preparation method. The catalyst produced by this method exhibits excellent performance in the high-temperature region and has few side reactions.

[0005] 2. Technical Solution: A copper-based carbon monoxide isothermal shift catalyst, characterized in that its composition by weight percentage is: 35-50% copper oxide, 25-40% zinc oxide, 5-15% aluminum oxide, 2-10% structural auxiliary metal oxide, and 1-5% modifying auxiliary metal oxide.

[0006] Furthermore, the structural additive metal is one or more of cerium, zirconium, calcium, magnesium, iron, and manganese.

[0007] Furthermore, the modifying agent metal is one or more of lithium, sodium, potassium, and rubidium.

[0008] A method for preparing a copper-based carbon monoxide isothermal shift catalyst, characterized by comprising the following steps: Step 1: Add sodium carbonate and deionized water to a reactor equipped with a stirrer and water bath heating, stir well, and divide into two equal portions; Step 2: Dissolve the modified metal salt in deionized water, then add it to the zinc nitrate solution and mix thoroughly. Step 3: Add the mixture from Step 2 at a uniform rate to one portion of the sodium carbonate solution generated in Step 1 for precipitation and aging; Step 4: Dissolve the structural aid metal salt in deionized water, then add it to the copper nitrate solution and mix thoroughly. Step 5: Add the mixture generated in Step 4 to another portion of the sodium carbonate solution generated in Step 1 at a uniform rate to allow for precipitation and aging; Step 6: Add the material obtained in Step 3 to the material obtained in Step 5 and mix thoroughly; after mixing, the material undergoes 5 sedimentation and washing cycles, and then alumina powder is added and the mixture is slurried for 0.3-0.5 hours. Step 7: After pulping, the material is filtered, dried, ground, granulated, roasted, and pressed into tablets to obtain the catalyst.

[0009] Furthermore, the molar concentration of the sodium carbonate solution in step one is 0.5-1.0 mol / L.

[0010] Furthermore, the modifying agent metal salt in step two is at least one of its corresponding metal nitrate or carbonate.

[0011] Furthermore, in step three, the precipitation temperature 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.

[0012] Furthermore, the structural aid metal salt in step four is at least one of its corresponding acetate or hydroxide.

[0013] Furthermore, in step five, the precipitation temperature is 75-77℃, the final pH value is 7.2-7.4, the aging temperature is 70-75℃, and the aging time is 0.4-0.8h.

[0014] Furthermore, in step six, the material mixing temperature is 65-67℃ and the mixing time is 0.3-0.5h; in step seven, the material roasting temperature is 450-550℃ and the roasting time is 3-5h.

[0015] 3. Beneficial effects: The catalyst prepared by the method provided by this 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

[0016] A copper-based carbon monoxide isothermal shift catalyst, characterized in that its composition by weight percentage is: 35-50% copper oxide, 25-40% zinc oxide, 5-15% aluminum oxide, 2-10% structural auxiliary metal oxide, and 1-5% modifying auxiliary metal oxide.

[0017] Furthermore, the structural additive metal is one or more of cerium, zirconium, calcium, magnesium, iron, and manganese.

[0018] Furthermore, the modifying agent metal is one or more of lithium, sodium, potassium, and rubidium.

[0019] A method for preparing a copper-based carbon monoxide isothermal shift catalyst, characterized by comprising the following steps: Step 1: Add sodium carbonate and deionized water to a reactor equipped with a stirrer and water bath heating, stir well, and divide into two equal portions; Step 2: Dissolve the modified metal salt in deionized water, then add it to the zinc nitrate solution and mix thoroughly. Step 3: Add the mixture from Step 2 at a uniform rate to one portion of the sodium carbonate solution generated in Step 1 for precipitation and aging; Step 4: Dissolve the structural aid metal salt in deionized water, then add it to the copper nitrate solution and mix thoroughly. Step 5: Add the mixture generated in Step 4 to another portion of the sodium carbonate solution generated in Step 1 at a uniform rate to allow for precipitation and aging; Step 6: Add the material obtained in Step 3 to the material obtained in Step 5 and mix thoroughly; after mixing, the material undergoes 5 sedimentation and washing cycles, and then alumina powder is added and the mixture is slurried for 0.3-0.5 hours. Step 7: After pulping, the material is filtered, dried, ground, granulated, roasted, and pressed into tablets to obtain the catalyst.

[0020] Furthermore, the molar concentration of the sodium carbonate solution in step one is 0.5-1.0 mol / L.

[0021] Furthermore, the modifying agent metal salt in step two is at least one of its corresponding metal nitrate or carbonate.

[0022] Furthermore, in step three, the precipitation temperature 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.

[0023] Furthermore, the structural aid metal salt in step four is at least one of its corresponding acetate or hydroxide.

[0024] Furthermore, in step five, the precipitation temperature is 75-77℃, the final pH value is 7.2-7.4, the aging temperature is 70-75℃, and the aging time is 0.4-0.8h.

[0025] Furthermore, in step six, the material mixing temperature is 65-67℃ and the mixing time is 0.3-0.5h; in step seven, the material roasting temperature is 450-550℃ and the roasting time is 3-5h. Specific implementation examples: 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).

[0027] CO conversion rate calculation formula: Where: Φ1: CO volume fraction in the intake air (raw material gas), % Φ2: CO volume fraction in the effluent (product gas), % 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.

[0028] Example 1 (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; (2) Dissolve 20g of cerium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 3.5g of potassium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5 L of a solution with a molar concentration of 0.70 mol / L copper nitrate, and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.2, and the mixture was aged at 70℃ for 0.4h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.3 hours.

[0029] (9) After the mixed material is washed and settled 5 times, 50g of alumina powder is added and the mixture is pulped for 0.5h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 550℃ for 3.0h, and graphite was added to form tablets to obtain catalyst S-1. The analytical data are shown in Tables 1 and 2 below.

[0030] Example 2 (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; (2) Dissolve 15g of cerium nitrate and 15g of calcium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 3g of potassium hydroxide and 2g of lithium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5L of a solution with a molar concentration of 0.8mol / L copper nitrate and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.2, and the mixture was aged at 72℃ for 0.6h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.4 h; (9) After the mixed material is washed and settled 5 times, 60g of alumina powder is added and the mixture is pulped for 0.4h. (10) After pulping, the material was filtered, dried, ground, and granulated. It was then calcined at 500℃ for 4.0 h, and graphite was added to form tablets to obtain catalyst S-2. The analytical data are shown in Tables 1 and 2 below.

[0031] Example 3 (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; (2) Dissolve 15g of calcium nitrate and 10g of magnesium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 4g of rubidium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5L of a solution with a molar concentration of 0.75mol / L copper nitrate and mix thoroughly; (7) The mixture from step (6) 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 mixture was aged at 72℃ for 0.7h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.6 h; (9) After the mixed material is washed and settled 5 times, 45g of alumina powder is added and the mixture is pulped for 0.5h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 500℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-3. The analytical data are shown in Tables 1 and 2 below.

[0032] Example 4 (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; (2) Dissolve 15g of calcium nitrate and 10g of magnesium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 4g of rubidium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5L of a solution with a molar concentration of 0.75mol / L copper nitrate and mix thoroughly; (7) The mixture from step (6) 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 mixture was aged at 72℃ for 0.7h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.6 h; (9) After the mixed material is washed and settled 5 times, 45g of alumina powder is added and the mixture is pulped for 0.5h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 500℃ for 3.5h, and graphite was added to form tablets to obtain catalyst S-4. The analytical data are shown in Tables 1 and 2 below.

[0033] Example 5 (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; (2) Dissolve 25g of zirconium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 5g of sodium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5L of a solution with a molar concentration of 0.85mol / L copper nitrate and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 77℃, the final pH value was 7.4, and the mixture was aged at 70℃ for 0.8h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.5 h; (9) After the mixed material is washed and settled 5 times, 40g of alumina powder is added and the mixture is pulped for 0.3h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 480℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-5. The analytical data are shown in Tables 1 and 2 below.

[0034] Example 6 (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; (2) Dissolve 15g of zirconium nitrate and 10g of manganese magnesium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 8g of potassium acetate in 100mL of deionized water; (6) Add the solution from step (5) to 1.5 L of a solution with a molar concentration of 0.70 mol / L copper nitrate, and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the mixture was aged at 70℃ for 0.6h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.5 h; (9) After the mixed material is washed and settled 5 times, 65g of alumina powder is added and the mixture is pulped for 0.6h; (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 500℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-6. The analytical data are shown in Tables 1 and 2 below.

[0035] Example 7 (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; (2) Dissolve 25g of cerium carbonate in 100ml of deionized water; (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; (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. (5) Dissolve 6g of sodium acetate in 100mL of deionized water; (6) Add the solution from step (5) to 1.5 L of a solution with a molar concentration of 0.70 mol / L copper nitrate, and mix thoroughly; (7) The mixture from step (6) 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 mixture was aged at 72℃ for 0.67h. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.6 h; (9) After the mixed material is washed and settled 5 times, 60g of alumina powder is added and the mixture is pulped for 0.5h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 520℃ for 3.5 h, and graphite was added to form tablets to obtain catalyst Y-7. The analytical data are shown in Tables 1 and 2 below.

[0036] Example 8 (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; (2) Dissolve 15g of zirconium carbonate and 10g of magnesium carbonate in 100ml of deionized water; (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; (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. (5) Dissolve 5g of sodium acetate and 2g of potassium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.52 L of a solution with a molar concentration of 0.7 mol / L copper nitrate, and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the mixture was aged at 72℃ for 0.7h. (8) At a temperature of 63°C, add the material obtained in step (4) to the material in step (7) and mix for 0.6 h; (9) After the mixed material is washed and settled 5 times, 35g of alumina powder is added and the mixture is pulped for 0.6h. (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 500℃ for 4.0h, and graphite was added to form tablets to obtain catalyst S-8. The analytical data are shown in Tables 1 and 2 below.

[0037] Example 9 (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; (2) Dissolve 15g of cerium carbonate and 10g of magnesium nitrate in 100ml of deionized water; (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; (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. (5) Dissolve 3g of sodium acetate and 4g of potassium hydroxide in 100mL of deionized water; (6) Add the solution from step (5) to 1.5 L of a 0.6 mol / L copper nitrate solution and mix thoroughly; (7) The mixture from step (6) was added to 2L of sodium carbonate solution at a uniform rate to carry out precipitation. The precipitation temperature was 75℃, the final pH value was 7.3, and the mixture was aged at 72℃ for 0.7h. (8) At a temperature of 63°C, add the material obtained in step (4) to the material in step (7) and mix for 0.6 h; (9) After the mixed material is washed and settled 5 times, 70g of alumina powder is added and the mixture is pulped for 0.6h; (10) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 470℃ for 4.0 h, and graphite was added to form tablets to obtain catalyst S-9. The analytical data are shown in Tables 1 and 2 below.

[0038] Comparative Example 1 (Example 1 without added structural additives) (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; (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. (3) Dissolve 3.5g of potassium hydroxide in 100mL of deionized water; (4) Add the solution from step (5) to 1.5L of a solution with a molar concentration of 0.7mol / L copper nitrate and mix thoroughly; (5) The mixture from step (6) was added to 2 mL 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 mixture was aged at 70℃ for 0.4 h. (6) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.3 h; (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. (8) After pulping, the material was filtered, dried, ground, and granulated, then calcined at 550℃ for 3.0h, and graphite was added to form tablets to obtain catalyst D-1. The analytical data are shown in Tables 1 and 2 below.

[0039] Comparative Example 2 (Example 1 without added modifiers) (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 of 2L each; (2) Dissolve 20g of cerium nitrate in 100ml of deionized water; (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; (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. (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. (8) At a temperature of 65°C, add the material obtained in step (4) to the material in step (7) and mix for 0.3 h; (9) After the mixed material is washed and settled 5 times, 50g of alumina powder is added and the mixture is pulped for 0.5h. (10) 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.

[0040] Comparative Example 3 Prepared according to Example 1 of patent CN 101786000 A.

[0041] 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... 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.

[0042] Table 1 Comparison of data from the examples and comparative examples. 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 Table 2 Comparison of data from the examples and comparative examples 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 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.

[0043] 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.

[0044] Although the present invention has been disclosed above with reference to preferred embodiments, these are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be defined by the scope of the claims of this application.

Claims

1. A method for preparing a copper-based carbon monoxide isothermal shift catalyst, characterized in that: A copper-based carbon monoxide isothermal shift catalyst, wherein the specific weight percentage composition is: copper oxide 35-50%, zinc oxide 25-40%, aluminum oxide 5-15%, structural additive metal oxide 2-10%, and modifying additive metal oxide 1-5%; The structural additive metal is one or more of cerium, zirconium, calcium, magnesium, iron, and manganese; The modifying agent metal is one or more of lithium, sodium, potassium, and rubidium; The preparation method includes the following steps: Step 1: Add sodium carbonate and deionized water to a reactor equipped with a stirrer and water bath heating, stir well, and divide into two equal portions; Step 2: Dissolve the structural aid metal salt in deionized water, then add it to the zinc nitrate solution and mix thoroughly. Step 3: Add the mixture from Step 2 at a uniform rate to one portion of the sodium carbonate solution generated in Step 1 for precipitation and aging; Step 4: Dissolve the modified metal salt in deionized water, then add it to the copper nitrate solution and mix thoroughly. Step 5: Add the mixture generated in Step 4 to another portion of the sodium carbonate solution generated in Step 1 at a uniform rate to allow for precipitation and aging; Step 6: Add the material obtained in Step 3 to the material obtained in Step 5 and mix thoroughly; after mixing, the material undergoes 5 sedimentation and washing cycles, and then alumina powder is added and the mixture is slurried for 0.3-0.5 hours. Step 7: After pulping, the material is filtered, dried, ground, granulated, roasted, and pressed into tablets to obtain the catalyst.

2. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: In step one, the molar concentration of the sodium carbonate solution is 0.5-1.0 mol / L.

3. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: The structural aid metal salt in step two is at least one of its corresponding nitrate or carbonate.

4. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: In step three, the precipitation temperature 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.

5. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: The modified auxiliary metal salt mentioned in step four is at least one of its corresponding acetate or hydroxide.

6. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: The precipitation temperature in step five is 75-77℃, the final pH value is 7.2-7.4, the aging temperature is 70-75℃, and the aging time is 0.4-0.8h.

7. The method for preparing a copper-based carbon monoxide isothermal shift catalyst according to claim 1, characterized in that: In step six, the material mixing temperature is 65-67℃ and the mixing time is 0.3-0.5h; in step seven, the material roasting temperature is 450-550℃ and the roasting time is 3-5h.

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