High-stability methanol carbonylation reaction catalyst and preparation method thereof
By using a catalyst composed of iridium, molybdenum, and tungsten compounds with activated carbon and lithium, sodium, potassium, magnesium, and calcium compounds, the problem of insufficient stability of existing catalysts is solved, realizing a highly efficient and environmentally friendly methanol carbonylation reaction, which is suitable for industries such as pharmaceuticals, pesticides, dyes, and coatings.
Patent Information
- Application Number
- CN202511692229.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-02-10
AI Technical Summary
Existing methanol carbonylation catalysts lack stability, leading to easy deactivation, which limits their application in industrial production and increases production costs.
A highly stable methanol carbonylation catalyst is formed by using compounds of iridium, molybdenum, and tungsten as active components, activated carbon as a support, and compounds of lithium, sodium, potassium, magnesium, and calcium as auxiliary agents through a specific preparation method.
It improves the activity and stability of the catalyst, extends the catalyst life, enhances the efficiency and selectivity of the methanol carbonylation reaction, reduces engineering consumption, reduces the generation of by-products, and is suitable for large-scale production and is environmentally friendly.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst technology, and in particular to a highly stable catalyst for methanol carbonylation reaction and its preparation method. Background Technology
[0002] Currently, the main industrial method for producing acetic acid is the methanol carbonylation process. Acetic acid is an important organic chemical raw material widely used in pharmaceuticals, pesticides, dyes, coatings, and other industries. The methanol carbonylation process typically uses methanol and CO as raw materials. Under catalytic conditions, methanol and CO are homogeneously mixed in the reaction system to produce acetic acid. The reaction temperature is typically 180–190°C, and the pressure is typically 2.9–3.1 MPa. Unreacted CO and other organic vapors are discharged from the top of the reactor and then pass through a conversion vessel to react with methanol and methyl acetate in the reaction solution, ultimately producing acetic acid. The main processes for synthesizing acetic acid by methanol carbonylation can be divided into high-pressure and low-pressure methods based on the pressure. The high-pressure method has now been largely replaced by the low-pressure method. This method has advantages such as readily available raw materials, mild reaction conditions, and high product selectivity.
[0003] The most commonly used industrial catalysts for methanol carbonylation are rhodium-based and iridium-based catalysts. These catalysts suffer from problems such as low activity, poor stability, and short lifespan during the reaction process. They are also prone to deactivation, which limits their application in industrial production and increases production costs. Summary of the Invention
[0004] The purpose of this invention is to provide a highly stable methanol carbonylation catalyst and its preparation method, so as to solve the problem of insufficient stability of existing methanol carbonylation catalysts.
[0005] To achieve the above objectives, the present invention provides a highly stable methanol carbonylation catalyst, comprising an active component, a support, and an auxiliary agent. The active component is a compound of iridium, molybdenum, and tungsten, the support is activated carbon, and the auxiliary agent is one or more compounds of lithium, sodium, potassium, magnesium, and calcium.
[0006] Preferably, the molar ratio of iridium, molybdenum and tungsten in the active component is 1:(0.5-2):(0.1-1).
[0007] Preferably, the mass of the auxiliary agent accounts for 0.1%-5% of the total mass of the catalyst.
[0008] Preferably, the activated carbon is petroleum coke-based activated carbon.
[0009] The preferred method for preparing petroleum coke-based activated carbon is as follows: Petroleum coke is pulverized to 150-200 mesh, then soaked in 1-5 mol / L hydrochloric acid or sulfuric acid and 1-5 mol / L sodium hydroxide for 1-3 hours to remove impurities. The treated petroleum coke is then mixed with steam and activated at 800-1000℃ for 1-3 hours. The activated product is washed with deionized water to remove residual impurities. The washed product is then dried at 100-120℃ for 6-12 hours to obtain petroleum coke-based activated carbon.
[0010] A method for preparing a highly stable catalyst for methanol carbonylation includes the following steps: S1. Dissolve iridium compound, molybdenum compound and tungsten compound in water in a certain proportion to obtain mixed solution A; S2. Add the carrier to mixed solution A and stir until homogeneous to obtain mixed solution B; S3. Impregnate the mixed solution B at a certain temperature, then dry and calcine to obtain the catalyst precursor; S4. Dissolve the auxiliary compound in water to obtain solution C; S5. Add the catalyst precursor to solution C, stir until homogeneous, then dry and calcine to obtain a highly stable methanol carbonylation catalyst.
[0011] Preferably, in step S1, the iridium compound is one of iridium chloride, iridium nitrate, or iridium acetate; the molybdenum compound is one of ammonium molybdate, sodium molybdate, or potassium molybdate; and the tungsten compound is one of ammonium tungstate, sodium tungstate, or potassium tungstate.
[0012] Preferably, in step (3), the immersion treatment temperature is 50-80℃ and the time is 2-6h.
[0013] Preferably, in step (3), the drying temperature is 80-120℃ and the time is 6-12h; the calcination temperature is 300-500℃ and the time is 4-8h.
[0014] Preferably, in step (5), the drying temperature is 80-120℃ and the time is 6-12h; the calcination temperature is 300-500℃ and the time is 4-8h.
[0015] The advantages and beneficial effects of using the above-mentioned highly stable methanol carbonylation catalyst and its preparation method are as follows: 1. The catalyst of the present invention uses compounds of iridium, molybdenum and tungsten as active components, activated carbon as a support, and compounds of lithium, sodium, potassium, magnesium and calcium as auxiliary agents. It has high activity, high stability and long life, and can effectively improve the efficiency and selectivity of methanol carbonylation reaction.
[0016] 2. The lithium, sodium, potassium, magnesium, and calcium compounds in this invention can form new compounds or catalytic active sites by being loaded onto the surface of a porous activated carbon support. This modification process improves the performance of the catalyst.
[0017] 3. The lithium, sodium, potassium, magnesium, and calcium compounds in this invention can act as stabilizers to protect the catalyst from certain environmental factors, thereby improving the stability and lifespan of the catalyst. They can also act as additives to adjust the catalytic performance by changing the structure or surface properties of the catalyst, affecting its acidity or alkalinity, and thus affecting its adsorption and conversion ability for specific reactants.
[0018] 4. The preparation method of the present invention is simple and easy to implement, low in cost, suitable for large-scale production, environmentally friendly, and will not produce secondary pollution.
[0019] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation
[0020] The technical solution of the present invention will be further described below through embodiments.
[0021] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. Unless otherwise defined, all reagents used in this invention are commercially available.
[0022] Example 1 A highly stable methanol carbonylation catalyst comprises an active component, a support, and an auxiliary agent. The active component consists of iridium chloride, ammonium molybdate, and ammonium tungstate; the support is activated carbon; and the auxiliary agent is potassium chloride. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:1:0.5. The auxiliary agent accounts for 1% of the total mass of the catalyst. The activated carbon is petroleum coke-based activated carbon.
[0023] The preparation method of petroleum coke-based activated carbon is as follows: Petroleum coke was pulverized to 150 mesh and then soaked in 3 mol / L hydrochloric acid and 4 mol / L sodium hydroxide for 1-3 hours to remove impurities. The treated petroleum coke was then mixed with steam and activated at 800℃ for 3 hours. The activated product was washed with deionized water to remove residual impurities. The washed product was then dried at 120℃ for 12 hours to obtain petroleum coke-based activated carbon.
[0024] A method for preparing a highly stable catalyst for methanol carbonylation includes the following steps: (1) Dissolve iridium chloride, ammonium molybdate and ammonium tungstate in water at a molar ratio of 1:1:0.5 to obtain mixed solution A; (2) Add activated carbon to mixed solution A and stir until homogeneous to obtain mixed solution B; (3) The mixed solution B was impregnated at 60°C for 4 hours, then dried at 100°C for 8 hours, and calcined at 400°C for 6 hours to obtain the catalyst precursor; (4) Dissolve potassium chloride in water to obtain solution C; (5) Add the catalyst precursor to solution C, stir evenly, dry at 100°C for 8 hours, and calcine at 400°C for 6 hours to obtain a highly stable methanol carbonylation catalyst.
[0025] The main catalyst is inexpensive and stable, maintaining a higher concentration in the reaction solution. It also boasts a higher space-time yield, increasing production capacity while reducing engineering costs. Furthermore, it results in a very low water content in the reaction solution, minimizing byproduct formation and making product quality easier to control. Adding molybdenum and tungsten compounds to the active component prevents hydrolysis of molybdenum and tungsten at excessively low pH levels, thus enhancing catalyst stability.
[0026] Example 2 A highly stable methanol carbonylation catalyst comprises an active component, a support, and an additive. The active component consists of iridium nitrate, sodium molybdate, and sodium tungstate; the support is activated carbon; and the additive is sodium chloride. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:1.5:0.8. The additive accounts for 2% of the total catalyst mass. The activated carbon is petroleum coke-based activated carbon.
[0027] The preparation method of petroleum coke-based activated carbon is as follows: Petroleum coke was pulverized to 200 mesh and then soaked in 5 mol / L hydrochloric acid and 5 mol / L sodium hydroxide for 1.5 h to remove impurities. The treated petroleum coke was then mixed with steam and activated at 1000℃ for 2 h. The activated product was washed with deionized water to remove residual impurities. The washed product was then dried at 100℃ for 10 h to obtain petroleum coke-based activated carbon.
[0028] A method for preparing a highly stable catalyst for methanol carbonylation includes the following steps: (1) Dissolve iridium nitrate, sodium molybdate and sodium tungstate in water at a molar ratio of 1:1.5:0.8 to obtain mixed solution A; (2) Add activated carbon to mixed solution A and stir until homogeneous to obtain mixed solution B; (3) Impregnate the mixed solution B at 70°C for 3 hours, then dry it at 110°C for 7 hours, and calcine it at 450°C for 5 hours to obtain the catalyst precursor; (4) Dissolve sodium chloride in water to obtain solution C; (5) Add the catalyst precursor to solution C, stir evenly, dry at 110°C for 7 h, and calcine at 450°C for 5 h to obtain a highly stable methanol carbonylation catalyst.
[0029] Example 3 A highly stable methanol carbonylation catalyst comprises an active component, a support, and an auxiliary agent. The active component consists of iridium acetate, potassium molybdate, and potassium tungstate; the support is activated carbon; and the auxiliary agent is calcium chloride. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:2:1. The auxiliary agent accounts for 3% of the total mass of the catalyst. The activated carbon is petroleum coke-based activated carbon.
[0030] The preparation method of petroleum coke-based activated carbon is as follows: Petroleum coke was pulverized to 180 mesh and then soaked in 5 mol / L sulfuric acid and 5 mol / L sodium hydroxide for 3 hours to remove impurities. The treated petroleum coke was then mixed with steam and activated at 900℃ for 3 hours. The activated product was washed with deionized water to remove residual impurities. The washed product was then dried at 110℃ for 10 hours to obtain petroleum coke-based activated carbon.
[0031] A method for preparing a highly stable catalyst for methanol carbonylation includes the following steps: (1) Dissolve iridium acetate, potassium molybdate and potassium tungstate in water in a molar ratio of 1:2:1 to obtain mixed solution A; (2) Add activated carbon to mixed solution A and stir until homogeneous to obtain mixed solution B; (3) Impregnate the mixed solution B at 80°C for 2 hours, then dry it at 120°C for 6 hours, and calcine it at 500°C for 4 hours to obtain the catalyst precursor; (4) Dissolve calcium chloride in water to obtain solution C; (5) Add the catalyst precursor to solution C, stir evenly, dry at 120°C for 6 h, and calcine at 500°C for 4 h to obtain a highly stable methanol carbonylation catalyst.
[0032] Comparative Example 1 A catalyst is composed of an active component and a support. The active component consists of iridium chloride, ammonium molybdate, and ammonium tungstate, and the support is activated carbon. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:1:0.5. The activated carbon is petroleum coke-based activated carbon.
[0033] A method for preparing a catalyst is as follows: (1) Dissolve iridium chloride, ammonium molybdate and ammonium tungstate in water in a molar ratio to obtain mixed solution A; (2) Add activated carbon to mixed solution A and stir until homogeneous to obtain mixed solution B; (3) The mixed solution B was impregnated at 60°C for 4 hours, then dried at 100°C for 8 hours, and calcined at 400°C for 6 hours to obtain the catalyst.
[0034] Comparative Example 2 A catalyst comprises an active component, a support, and an auxiliary agent. The active component is iridium chloride, ammonium molybdate, and ammonium tungstate, and the auxiliary agent is potassium chloride. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:1:0.5. The support is an ion exchange resin.
[0035] A method for preparing a catalyst is as follows: (1) Dissolve iridium chloride, ammonium molybdate and ammonium tungstate in water in a molar ratio to obtain mixed solution A; (2) Add the ion exchange resin to the mixed solution A and stir until homogeneous to obtain mixed solution B; (3) The mixed solution B was impregnated at 60°C for 4 hours, then dried at 100°C for 8 hours, and calcined at 400°C for 6 hours to obtain the catalyst precursor; (4) Dissolve potassium chloride in water to obtain solution C; (5) Add the catalyst precursor to solution C, stir evenly, dry at 100°C for 8 hours, and calcine at 400°C for 6 hours to obtain the highly stable methanol carbonylation catalyst.
[0036] Comparative Example 3 A catalyst comprises an active component, a support, and an additive. The active component is iridium chloride, ammonium molybdate, and ammonium tungstate. The support is petroleum coke-based activated carbon, and the additive is iodide. The molar ratio of iridium, molybdenum, and tungsten in the active component is 1:1:0.5. The additive accounts for 1% of the total mass of the catalyst. The activated carbon is petroleum coke-based activated carbon.
[0037] A method for preparing a catalyst is as follows: (1) Dissolve iridium chloride, ammonium molybdate and ammonium tungstate in water in a molar ratio to obtain mixed solution A; (2) Add petroleum coke-based activated carbon to mixed solution A and stir until homogeneous to obtain mixed solution B; (3) The mixed solution B was impregnated at 60°C for 4 hours, then dried at 100°C for 8 hours, and calcined at 400°C for 6 hours to obtain the catalyst precursor; (4) Dissolve iodide in water to obtain solution C; (5) Add the catalyst precursor to solution C, stir evenly, dry at 100°C for 8 hours, and calcine at 400°C for 6 hours to obtain the highly stable methanol carbonylation catalyst.
[0038] The catalysts prepared in Examples 1-3 and Comparative Examples 1-3 were used in the methanol carbonylation reaction under the following conditions: reaction temperature 180°C, reaction pressure 3 MPa, methanol to carbon monoxide molar ratio 1:1.5, and space velocity 2000 h⁻¹. -1 The reaction results are shown in Table 1.
[0039] Table 1 Reaction Results
[0040] As shown in Table 1, the highly stable methanol carbonylation catalyst of this invention is significantly superior to the catalyst in the comparative example in terms of methanol conversion, acetic acid selectivity, and catalyst stability. This is because the catalyst of this invention incorporates molybdenum and tungsten elements, as well as additives, which improve the catalyst's activity and stability.
[0041] Comparative Example 1 did not add any additives, resulting in a lower conversion rate. The carrier in Comparative Example 2 differs from that of this invention. This invention uses petroleum coke-based activated carbon, which is environmentally friendly, low-cost, and possesses a well-developed pore structure and a large specific surface area, providing numerous surface active sites that facilitate the loading and dispersion of the catalyst's active substances. It is also chemically stable, capable of loading noble metals, making their loading and recovery easier. Furthermore, it exhibits excellent adsorption properties, helping to optimize the reaction environment and improve catalytic efficiency. The additives used in Comparative Example 3 differ from those of this invention. This invention uses compounds of lithium, sodium, potassium, magnesium, and calcium as additives. These compounds can act as stabilizers, protecting the catalyst from certain environmental factors, thereby improving its stability and lifespan. They can also act as additives, modifying the catalyst's structure or surface properties to adjust its catalytic performance, affecting its acidity and basicity, and thus influencing its adsorption and conversion capabilities for specific reactants.
[0042] Therefore, the present invention employs the above-mentioned highly stable methanol carbonylation reaction catalyst and its preparation method. The catalyst uses compounds of iridium, molybdenum and tungsten as active components, activated carbon as a support, and compounds of alkali metals or alkaline earth metals as promoters. It has high activity, high stability and long lifespan, and can effectively improve the efficiency and selectivity of methanol carbonylation reaction.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A highly stable catalyst for methanol carbonylation, characterized in that: It includes an active component, a carrier, and an auxiliary agent. The active component is a compound of iridium, molybdenum, and tungsten. The carrier is activated carbon. The auxiliary agent is one or more compounds of lithium, sodium, potassium, magnesium, and calcium.
2. The highly stable methanol carbonylation catalyst according to claim 1, characterized in that: The molar ratio of iridium, molybdenum and tungsten in the active component is 1:(0.5-2):(0.1-1).
3. The highly stable methanol carbonylation catalyst according to claim 1, characterized in that: The mass of the auxiliary agent accounts for 0.1%-5% of the total mass of the catalyst.
4. The highly stable methanol carbonylation catalyst according to claim 1, characterized in that: The activated carbon is petroleum coke-based activated carbon.
5. The highly stable methanol carbonylation catalyst according to claim 4, characterized in that: The preparation method of petroleum coke-based activated carbon is as follows: Petroleum coke is pulverized to 150-200 mesh, then soaked in 1-5 mol / L hydrochloric acid or sulfuric acid and 1-5 mol / L sodium hydroxide for 1-3 hours to remove impurities. The treated petroleum coke is then mixed with steam and activated at 800-1000℃ for 1-3 hours. The activated product is washed with deionized water to remove residual impurities. The washed product is then dried at 100-120℃ for 6-12 hours to obtain petroleum coke-based activated carbon.
6. A method for preparing a highly stable methanol carbonylation catalyst according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Dissolve iridium compound, molybdenum compound and tungsten compound in water in a certain proportion to obtain mixed solution A; S2. Add the carrier to mixed solution A and stir until homogeneous to obtain mixed solution B; S3. Impregnate the mixed solution B at a certain temperature, then dry and calcine to obtain the catalyst precursor; S4. Dissolve the auxiliary compound in water to obtain solution C; S5. Add the catalyst precursor to solution C, stir until homogeneous, then dry and calcine to obtain a highly stable methanol carbonylation catalyst.
7. The method for preparing a highly stable methanol carbonylation catalyst according to claim 6, characterized in that: In step S1, the iridium compound is one of iridium chloride, iridium nitrate, or iridium acetate; the molybdenum compound is one of ammonium molybdate, sodium molybdate, or potassium molybdate; and the tungsten compound is one of ammonium tungstate, sodium tungstate, or potassium tungstate.
8. The method for preparing a highly stable methanol carbonylation catalyst according to claim 6, characterized in that: In step (3), the immersion treatment temperature is 50-80℃ and the time is 2-6h.
9. The method for preparing a highly stable methanol carbonylation catalyst according to claim 6, characterized in that: In step (3), the drying temperature is 80-120℃ and the time is 6-12h; the calcination temperature is 300-500℃ and the time is 4-8h.
10. The method for preparing a highly stable methanol carbonylation catalyst according to claim 6, characterized in that: In step (5), the drying temperature is 80-120℃ and the time is 6-12h; the calcination temperature is 300-500℃ and the time is 4-8h.