Preparation method of carbon monoxide isothermal conversion catalyst and application thereof

Abstract

The application provides a preparation method and application of a carbon monoxide isothermal shift catalyst, and relates to the technical field of catalysts; the method comprises the following steps: respectively configuring a sodium carbonate solution, a mixed solution of copper nitrate and zinc nitrate in which a structure assistant metal salt is dissolved; uniformly adding the mixed solution of copper nitrate and zinc nitrate in which the structure assistant metal salt is dissolved into the sodium carbonate solution for co-precipitation and aging to obtain a mixture; after the mixture is washed for several times, alumina powder is added for beating; the solid product of the material after beating is collected and dried, a modified assistant is added, and then the material is rolled, granulated, dried, calcined and pressed into a tablet to obtain the catalyst; the catalyst prepared by the application has excellent heat resistance and is suitable for isothermal shift reaction of high CO volume content.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a method for preparing a carbon monoxide isothermal shift catalyst and its application. Background Technology

[0002] Chemical projects based on coal energy represent the main development direction of clean coal technology. The development and large-scale industrial application of coal-to-olefins, coal-to-gas, and coal-to-diesel technologies will break down the technological boundaries between the traditional coal chemical industry and petrochemical enterprises. CO conversion, as an important stage after coal chemical gasification, has mature process schemes, and currently most of them adopt isothermal conversion and adiabatic conversion technologies.

[0003] In traditional industrial production, CO converters mostly use conversion furnaces. Because the CO conversion reaction is a strong heat dissipation reaction and a thermodynamically controlled process, it adopts a multiphase, multi-heat exchange reaction mode. This leads to a series of problems such as relatively complex CO conversion, high heat loss, high steam consumption, and high equipment cost.

[0004] Compared with adiabatic shift conversion technology, isothermal shift conversion technology has the following characteristics: (1) Less catalyst and longer lifespan; a heat transfer unit is set in the reactor, so that the shift reaction proceeds along the optimal temperature curve, and the amount of catalyst used is minimized; the catalyst bed temperature is lower, which extends the lifespan of the catalyst. (2) Reduced system resistance; since the shift reaction is carried out at a lower temperature, the conversion of CO is improved, the process is shortened, the number of equipment is reduced, and the system resistance drop is reduced. (3) Simple process and easy operation; the reaction temperature can be controlled by controlling the steam drum pressure, and the operation is simple.

[0005] The catalysts currently used with isothermal reactors have the problem of poor heat resistance and low performance in the high-temperature zone. When the temperature is above 300℃, the CO conversion rate shows a significant downward trend, making them unsuitable for high CO content conversion reactions. Summary of the Invention

[0006] The present invention aims to provide a method for preparing a carbon monoxide isothermal shift catalyst and its application. On the one hand, the method utilizes the co-precipitation of metal ions of structural additives with Cu ions, resulting in high dispersion of Cu in the product catalyst, effectively inhibiting the thermal growth of Cu grains during the reaction. On the other hand, the modified additive metal and Al play a dual-carrier role, improving the mass and heat transfer performance of the product catalyst and enhancing its heat resistance, making it suitable for isothermal shift reactions with high CO volume content.

[0007] To achieve the above objectives, the present invention proposes the following technical solution: a method for preparing a carbon monoxide isothermal shift catalyst, comprising the following steps:

[0008] (1) Prepare sodium carbonate solution and a mixed solution of copper nitrate and zinc nitrate containing dissolved metal salts of structural aids, respectively;

[0009] (2) A mixed solution of copper nitrate and zinc nitrate containing dissolved structural aid metal salts was added to a sodium carbonate solution at a uniform rate for co-precipitation and aging.

[0010] (3) After the mixture has settled and aged, it is washed several times and then alumina powder is added to make a slurry.

[0011] (4) Collect and dry the solid products of the pulped material;

[0012] (5) After adding a modifying agent to the dried solid product, the product is milled, granulated, dried, calcined, and pressed into tablets to obtain the catalyst.

[0013] Furthermore, in step (1), the molar concentration of the sodium carbonate solution is 0.5–1.0 mol / L, and the Cu in the mixed solution of copper nitrate and zinc nitrate containing dissolved structural aid metal salts is... 2+ The concentration is 37–39 g / L, and the Cu / Zn molar ratio is 1.0–1.05.

[0014] Furthermore, in step (1), the metal of the structural aid metal salt is one or more of cerium, zirconium, and manganese.

[0015] Furthermore, in step (1), the molar ratio of Cu to the metal in the mixed solution of copper nitrate and zinc nitrate containing the structural aid metal salt is 9.5 to 10.5.

[0016] Furthermore, in step (2), the precipitation temperature is 65-67℃, the final pH value is 7.1-7.3, the aging temperature is 65-67℃, and the aging time is 0.4-0.8h.

[0017] Furthermore, in step (3), the alumina powder slurrying time is 0.3 to 0.5 hours.

[0018] Furthermore, in step (4), the temperature of the material after drying and pulping is 100-105℃, and the drying time is 8-10h.

[0019] Furthermore, in step (5), the modifying agent is a chromium nitrate, and the molar ratio of Cu in the catalyst to the metal in the modifying agent is 14.5 to 15.5.

[0020] Furthermore, in step (5), the grinding time is 40-60 min; the calcination temperature is 350-500℃; and the calcination time is 3-5 h.

[0021] Another technical solution of the present invention discloses the application of the carbon monoxide isothermal shift catalyst prepared by the above preparation method in the carbon monoxide isothermal shift reaction.

[0022] As can be seen from the above technical solutions, the technical solutions of the present invention have achieved the following beneficial effects:

[0023] The present invention discloses a method for preparing a carbon monoxide isothermal conversion catalyst and its application. The method includes: (1) preparing a sodium carbonate solution and a mixed solution of copper nitrate and zinc nitrate containing dissolved structural additive metal salts; (2) uniformly adding the mixed solution of copper nitrate and zinc nitrate containing dissolved structural additive metal salts to the sodium carbonate solution for co-precipitation and aging; (3) washing the precipitated and aged mixture several times, and then adding alumina powder to slurry; (4) collecting and drying the solid product of the slurry; (5) adding a modifying agent to the dried solid product and then grinding, granulating, drying, calcining, and pressing into tablets to obtain the catalyst. The catalyst prepared by the above steps firstly achieves high dispersion of Cu in the catalyst due to the co-precipitation of metal ions and Cu ions by the structural aid, effectively inhibiting the thermal growth of Cu grains during the reaction; secondly, the use of modified metal and Al as dual carriers further disperses Cu grains, ultimately improving the mass and heat transfer performance of the catalyst and enhancing its heat resistance. This makes the prepared catalyst suitable for isothermal shift reactions with high CO volume content, fully matching the current isothermal reactor.

[0024] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0025] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the embodiments. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0027] The terms "first," "second," and similar words used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the element or object preceding "comprising" encompasses the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0028] Based on the superior application prospects of isothermal shift conversion technology in CO conversion reactions, it has been widely used to replace adiabatic shift conversion technology in CO conversion processes. As a crucial factor affecting CO conversion efficiency, the compatibility of the catalyst with isothermal shift conversion technology significantly impacts the CO conversion rate. Existing catalysts exhibit poor heat resistance, with performance significantly decreasing at higher temperatures, making them unsuitable for high-CO-content shift reactions. This invention aims to disclose a method for preparing a carbon monoxide isothermal shift catalyst and its application. Using structural and modifying metal additives, a catalyst with excellent heat resistance is prepared, suitable for isothermal shift reactions with high CO volume content.

[0029] The method for preparing a carbon monoxide isothermal shift catalyst disclosed in this invention includes the following steps:

[0030] (1) Prepare a sodium carbonate solution and a mixed solution of copper nitrate and zinc nitrate containing dissolved structural aid metal salts, respectively; wherein the molar concentration of the sodium carbonate solution is 0.5–1.0 mol / L, the metal of the structural aid metal salt is one or more of cerium, zirconium, and manganese, and the Cu in the mixed solution of copper nitrate and zinc nitrate is... 2+ The concentration is 37–39 g / L, the Cu / Zn molar ratio is 1.0–1.05, and the metal molar ratio in Cu and the structural aid metal salt is 9.5–10.5;

[0031] (2) A mixed solution of copper nitrate and zinc nitrate containing dissolved structural additive metal salts was added to a sodium carbonate solution at a uniform rate for co-precipitation and aging; wherein the precipitation temperature was 65-67℃ and the final pH value was 7.1-7.3; the aging temperature was 65-67℃ and the aging time was 0.4-0.8h;

[0032] (3) After the mixture has settled and aged, it is washed several times and then alumina powder is added to make a pulp. The pulping time is 0.3 to 0.5 hours.

[0033] (4) Collect and dry the solid products of the pulped material at a temperature of 100-105℃ for 8-10 hours;

[0034] (5) After adding a modifying agent to the dried solid product, the product is milled, granulated, dried, calcined, and pressed into tablets to obtain a catalyst; wherein the milling time is 40-60 min, the calcination temperature is 350-500℃, the calcination time is 3-5 h, the modifying agent is chromium nitrate, and the molar ratio of Cu in the catalyst to the metal ions in the modifying agent is 14.5-15.5.

[0035] The catalyst prepared by the above method can be used in the carbon monoxide isothermal shift reaction. The preparation method and application of the carbon monoxide isothermal shift catalyst disclosed in this invention will be further described in detail below with reference to specific embodiments.

[0036] The carbon monoxide isothermal shift reaction process is as follows: The feed gas is reacted with the carbon monoxide isothermal shift catalyst prepared in this invention. The reaction conditions include: feed gas composition (v / v%): CO 20-60%, CO2 4-10%, H2 15-30%, CH4 5-10%, with the remainder being N2; vapor-to-gas ratio (water vapor / dry gas molar ratio) 0.45; reaction pressure 2.0℃-3.0MPa; and space velocity 2000h⁻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); reducing pressure: 0.4-0.5 MPa; reducing space velocity: 1000 h⁻¹ -1 The temperature was slowly increased to 230℃ at a programmed heating rate of 1℃ / 3min and held for 2.0h.

[0037] The formula for calculating CO conversion rate is:

[0038]

[0039] Wherein, Φ1 represents the CO volume fraction in the inlet gas (raw material gas), %; Φ2 represents the CO volume fraction in the outlet gas (product gas), %.

[0040] Example 1

[0041] Add 300g of sodium carbonate and 6L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 38 g / L, Zn 2+A mixture of 45g of cerium nitrate and zirconium nitrate with a concentration of 39.5g / L was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added to a sodium carbonate solution at a uniform rate to precipitate the material at 65℃. The final pH value was 7.2, and the material was aged at 65℃ for 0.4h. After mixing, the material was washed three times by sedimentation, and 35g of alumina powder was added and the mixture was slurried for 0.5h. After slurrying, the material was filtered and treated in an oven at 100℃ for 8h. After drying, the material was placed in a mixer and mill, 50g of chromium nitrate was added, and an appropriate amount of water was added for milling for 50min. After granulation and drying, the material was calcined at 450℃ for 3.0h, and then graphite was added to form tablets to obtain catalyst S-1.

[0042] Example 2

[0043] Add 300g of sodium carbonate and 5.5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 37.5 g / L, Zn 2+ With a concentration of 39 g / L, 42 g of manganese nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 67℃ and an endpoint pH of 7.3. The mixture was then aged at 66℃ for 0.3 h. After mixing, the material was washed three times by sedimentation and then slurried with 36.5 g of alumina powder for 0.4 h. The slurry was then filtered and dried in an oven at 105℃ for 6 h. After drying, the material was placed in a mixing mill, 47 g of chromium nitrate was added, and an appropriate amount of water was added for milling for 50 min. After granulation and drying, the material was calcined at 420℃ for 3.5 h and then pressed into tablets with graphite to obtain catalyst S-2.

[0044] Example 3

[0045] Add 300g of sodium carbonate and 5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 38 g / L, Zn 2+ A mixture of 44g of cerium nitrate, zirconium nitrate, and manganese nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate at a concentration of 39.5g / L. The copper nitrate and zinc nitrate solution was then added to a sodium carbonate solution at a uniform rate to induce precipitation at 65℃. The final pH value was 7.2, and the mixture was aged at 65℃ for 0.4h. After mixing, the material underwent three sedimentation and washing cycles, and 34g of alumina powder was added for 0.5h of pulping. The pulped material was then filtered and treated in a 100℃ oven for 8h. After drying, the material was placed in a mixing mill, 52g of chromium nitrate was added, and an appropriate amount of water was added for grinding for 45min. After granulation and drying, the material was calcined at 500℃ for 3.0h, and then graphite was added to form tablets to obtain catalyst S-3.

[0046] Example 4

[0047] Add 300g of sodium carbonate and 6L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 37 g / L, Zn 2+ With a concentration of 38.5 g / L, 45 g of zirconium nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 66℃ and a final pH of 7.1. The mixture was then aged at 67℃ for 0.5 h. After mixing, the material was washed three times by sedimentation and 38 g of alumina powder was added and the mixture was pulped for 0.4 h. The pulped material was then filtered and dried in an oven at 105℃ for 6.5 h. After drying, the material was placed in a mixing mill, 49 g of chromium nitrate was added, and an appropriate amount of water was added for grinding for 55 min. After granulation and drying, the material was calcined at 450℃ for 3.0 h and then pressed into tablets with graphite to obtain catalyst S-4.

[0048] Example 5

[0049] Add 300g of sodium carbonate and 5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 37.5 g / L, Zn 2+ With a concentration of 39 g / L, 45 g of cerium nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was then added to a sodium carbonate solution at a uniform rate to precipitate the material at 66°C. The final pH value was 7.2, and the material was aged at 67°C for 0.4 h. After mixing, the material was washed three times by sedimentation, and 36 g of alumina powder was added and the mixture was slurried for 0.5 h. After slurrying, the material was filtered and treated in an oven at 105°C for 7.0 h. After drying, the material was placed in a mixer and mill, 46 g of chromium nitrate was added, and an appropriate amount of water was added for milling for 60 min. After granulation and drying, the material was calcined at 500°C for 3.0 h, and then graphite was added to form tablets to obtain catalyst S-5.

[0050] Example 6

[0051] Add 300g of sodium carbonate and 5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 37.5 g / L, Zn 2+With a concentration of 39 g / L, 45 g of manganese nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 66℃ and a final pH of 7.2. The mixture was then aged at 67℃ for 0.4 h. After mixing, the material was washed three times by sedimentation and then slurryed with 36 g of alumina powder for 0.5 h. The slurry was then filtered and dried in an oven at 105℃ for 7.0 h. After drying, the material was placed in a mixing mill, 46 g of chromium nitrate was added, and an appropriate amount of water was added for milling for 40 min. After granulation and drying, the material was calcined at 500℃ for 3.0 h and then pressed into tablets with graphite to obtain catalyst S-6.

[0052] Example 7

[0053] Add 300g of sodium carbonate and 5.5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 39 g / L, Zn 2+ With a concentration of 39.0 g / L, 45 g of a mixture of cerium nitrate and manganese nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 65℃ and a final pH of 7.2. The mixture was then aged at 67℃ for 0.5 h. After mixing, the material was washed three times by sedimentation and 36 g of alumina powder was added and the mixture was pulped for 0.3 h. The pulped material was then filtered and dried in an oven at 100℃ for 7.0 h. After drying, the material was placed in a mixing mill, 45 g of chromium nitrate was added, and an appropriate amount of water was added for grinding for 50 min. After granulation and drying, the material was calcined at 500℃ for 3.0 h and then pressed into tablets with graphite to obtain catalyst S-7.

[0054] Example 8

[0055] Add 300g of sodium carbonate and 5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 37.5 g / L, Zn 2+ With a concentration of 39 g / L, 45 g of manganese nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 66℃ and a final pH of 7.2. The mixture was then aged at 67℃ for 0.4 h. After mixing, the material was washed three times by sedimentation and 36 g of alumina powder was added and the mixture was pulped for 0.5 h. The pulped material was then filtered and dried in an oven at 105℃ for 7.0 h. After drying, the material was placed in a mixing mill, 46 g of chromium nitrate was added, and an appropriate amount of water was added for grinding for 55 min. After granulation and drying, the material was calcined at 460℃ for 3.0 h and then pressed into tablets with graphite to obtain catalyst S-8.

[0056] Example 9

[0057] Add 300g of sodium carbonate and 5L of deionized water to a reactor equipped with a stirrer and water bath heating, and stir until homogeneous; prepare a 2L mixed solution of copper nitrate and zinc nitrate, Cu 2+ The concentration is 38 g / L, Zn 2+ With a concentration of 39.5 g / L, 45 g of zirconium nitrate was dissolved in a mixed solution of copper nitrate and zinc nitrate. The mixed solution of copper nitrate and zinc nitrate was added uniformly to a sodium carbonate solution for precipitation at a temperature of 66℃ and a final pH of 7.3. The solution was then aged at 67℃ for 0.4 h. After mixing, the material was washed three times by sedimentation and then slurried with 35 g of alumina powder for 0.5 h. The slurry was then filtered and dried in an oven at 100℃ for 7.0 h. After drying, the material was placed in a mixer and milled with 45 g of chromium carbonate and an appropriate amount of water for 45 min. After granulation and drying, the material was calcined at 480℃ for 3.0 h and then pressed into tablets with graphite to obtain catalyst S-9.

[0058] Comparative Example 1

[0059] The difference between Comparative Example 1 and Example 1 is that no structural additives were added to the prepared mixed solution of copper nitrate and zinc nitrate, and catalyst D-1 was finally obtained.

[0060] Comparative Example 2

[0061] The difference between Comparative Example 2 and Example 1 is that no modifying agent was added during the catalyst preparation process, and the final catalyst D-2 was obtained.

[0062] The catalysts prepared in Examples 1-9 and Comparative Examples 1-2 were used in the above-mentioned carbon monoxide isothermal conversion reaction. The CO content in the feed gas and product gas was monitored sequentially at the inlet temperatures of 250°C, 280°C and 330°C, and the CO conversion rate was calculated as shown in Tables 1 to 3 below. The microcrystalline particle size data of each catalyst before and after the carbon monoxide isothermal conversion reaction are shown in Table 4.

[0063] Table 1. Comparison of catalyst effects between the examples and comparative examples at an isothermal bed inlet temperature of 250℃.

[0064] catalyst Inlet temperature / °C Hot spot temperature / ℃ CO content in raw gas / % CO conversion rate / % S-1 250 285 30 94.5 S-2 250 282 30 94.0 S-3 250 280 30 94.6 S-4 250 280 30 93.7 S-5 250 284 30 93.5 S-6 250 285 30 93.0 S-7 250 283 30 93.1 S-8 250 284 30 93.6 S-9 250 283 30 93.8 D-1 250 283 30 92.9 D-2 250 284 30 92.6

[0065] Table 2 Comparison of catalyst effects between the examples and comparative examples at an isothermal bed inlet temperature of 280℃

[0066] catalyst Inlet temperature / °C Hot spot temperature / ℃ CO content in raw gas / % CO conversion rate / % S-1 280 310 30 92.5 S-2 280 308 30 92.0 S-3 280 307 30 92.4 S-4 280 308 30 92.2 S-5 280 309 30 92.1 S-6 280 306 30 91.9 S-7 280 305 30 92.0 S-8 280 305 30 91.8 S-9 280 305 30 91.9 D-1 280 302 30 85.5 D-2 280 303 30 87.2

[0067] Table 3. Comparison of catalyst effects between the examples and comparative examples at an isothermal bed inlet temperature of 330℃.

[0068] catalyst Inlet temperature / °C Hot spot temperature / ℃ CO content in raw gas / % CO conversion rate / % S-1 300 328 30 91.3 S-2 300 328 30 91.0 S-3 300 325 30 91.6 S-4 300 325 30 91.2 S-5 300 326 30 91.0 S-6 300 330 30 90.5 S-7 300 326 30 90.6 S-8 300 327 30 90.3 S-9 300 328 30 90.0 D-1 300 320 30 84.6 D-2 300 319 30 81.6

[0069] Table 4 Comparison of grain size data before and after heat resistance in the examples and comparative examples.

[0070]

[0071]

[0072] As can be seen from the data in Tables 1 to 3, the excellent heat resistance of the catalyst prepared by this invention gradually becomes more prominent with the increase of the isothermal reaction temperature. Table 4 shows the crystallite size data of the active components Cu and ZnO in the catalyst, indicating that the growth trend of Cu and ZnO crystallites in the catalyst prepared in this application is suppressed. This is because during catalyst preparation, the metal ions of the structural aid co-precipitate with Cu ions, allowing Cu to initially disperse and precipitate; then, the added modifying aid and Al act as a dual carrier, further achieving high dispersion of Cu; the tendency of highly dispersed Cu crystallites in the catalyst to grow under heat during the reaction is significantly reduced. That is, the increase of structural aids and modifying aids makes the active components highly dispersed in the catalyst, thereby suppressing the thermal growth of Cu crystallites during the reaction, thus giving the prepared catalyst excellent heat resistance. In application, because its active components can fully contact and react with CO in the reaction, the CO conversion rate of the catalyst is effectively improved, especially under reaction conditions above 300℃, where the catalytic performance advantage is significant.

[0073] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. The application of a carbon monoxide isothermal shift catalyst in a carbon monoxide isothermal shift reaction, characterized in that, The conditions for the isothermal shift reaction of carbon monoxide include: Based on volume concentration, the composition of the raw gas is: CO 20-60%, CO2 4-10%, H2 15-30%, CH4 5-10%, with the remainder being N2, and the molar ratio of water vapor to dry gas is 0.

45. Reaction pressure 2.0-3.0 MPa, space velocity 2000 h⁻¹ -1 Inlet temperature 280-300℃; When the inlet temperature of the isothermal bed is 300℃ and the CO volume concentration is 30%, the highest CO conversion rate is 91.3%. The preparation method of the carbon monoxide isothermal shift catalyst includes the following steps: (1) Prepare sodium carbonate solution and a mixed solution of copper nitrate and zinc nitrate containing dissolved metal salts of structural additives, respectively; (2) A mixed solution of copper nitrate and zinc nitrate containing dissolved structural aid metal salt is added at a constant rate to a sodium carbonate solution for co-precipitation and aging; wherein the metal of the structural aid metal salt is one or more of cerium, zirconium, and manganese; (3) After the mixture has settled and aged, it is washed several times and then alumina powder is added to make a slurry. (4) Collect and dry the solid products of the pulped material; (5) After adding a modifying agent to the dried solid product, the product is milled, granulated, dried, calcined, and pressed into tablets to obtain a catalyst; wherein the modifying agent is a chromium nitrate and the molar ratio of Cu in the catalyst to the metal in the modifying agent is 14.5~15.

5.

2. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, In step (1), the molar concentration of the sodium carbonate solution is 0.5~1.0 mol / L, and the Cu in the mixed solution of copper nitrate and zinc nitrate containing dissolved structural aid metal salts is... 2+ The concentration is 37~39 g / L, and the Cu / Zn molar ratio is 1.0~1.

05.

3. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, In step (1), the mixed solution of copper nitrate and zinc nitrate containing the structural aid metal salt is dissolved, and the molar ratio of Cu to the metal in the structural aid metal salt is 9.5~10.

5.

4. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, In step (2), the precipitation temperature is 65~67℃ and the final pH value is 7.1~7.3; the aging temperature is 65~67℃ and the aging time is 0.4~0.8h.

5. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, In step (3), the alumina powder slurrying time is 0.3~0.5h.

6. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, The temperature of the material after drying and pulping in step (4) is 100~105℃, and the drying time is 8~10h.

7. The application of the carbon monoxide isothermal shift catalyst according to claim 1 in the carbon monoxide isothermal shift reaction, characterized in that, In step (5), the grinding time is 40-60 min; the roasting temperature is 350-500℃; and the roasting time is 3-5 h.

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