A method for producing 2-methylpropenol and a method for producing a catalyst

Abstract

The application discloses a 2-methyl propenol preparation method and a catalyst preparation method. The 2-methyl propenol preparation method comprises the following steps: after a catalyst is pretreated, the catalyst is contacted with methyl propenal and hydrogen, and then reacted to generate 2-methyl propenol; and the catalyst is a NaY molecular sieve loaded Ni-In bimetallic catalyst. The application realizes the continuous production of 2-methyl propenol under a solvent-free condition by adopting a fixed bed reactor, taking methyl propenal as a reactant and hydrogen as a reducing agent. The conversion rate of methyl propenal on the Ni-In bimetallic catalyst reaches 98%, the selectivity of 2-methyl propenol is 90%, and the catalyst shows extremely high stability.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of 2-methylpropenol and a preparation method of a catalyst, and belongs to the technical field of chemical industry. BACKGROUND

[0002] 2-methylpropenol is a very important fine chemical, which is widely used in the production of polymer monomers, surfactants, synthetic resin additives and polycarboxylic acid superplasticizer.

[0003] The existing preparation process of 2-methylpropenol can be roughly divided into: 1, chlor-alkali method, 2, hydrogen transfer method, 3, selective hydrogenation method and 4, dehydration method. The chlor-alkali method is the main method for large-scale production of 2-methylpropenol at present, which generates isobutene chloride through the reaction of isobutene and chlorine, and then generates 2-methylpropenol through the hydroxyl substitution reaction of isobutene chloride under alkaline conditions. The process has harsh reaction conditions, and it is difficult to separate the product and recover the solvent, and a large amount of by-product ether is generated; the hydrogen transfer method mainly uses small molecule alcohols as hydrogen donor to transfer the hydrogen on the hydroxyl group to the carbonyl group of methylpropenal. The method realizes the coupling of dehydrogenation and hydrogenation. US4731488 uses magnesium oxide as a catalyst to produce methylpropenol, but the reaction requires a high temperature. Chinese patent (CN106984356A) uses ethanol as a hydrogen donor, and acetal as a product. The dehydration method uses 2-methyl-1,3-propanediol as a raw material to realize the preparation of methylpropenol through contact with a dehydrating agent.

[0004] Compared with the above three production processes, the selective hydrogenation is a more efficient production process, but there are still corresponding technical problems to be solved. Chinese invention patent (CN102167657B) reports a method for selectively hydrogenating 2-methylpropenol, which uses a kettle reactor and a series of solvents. Chinese invention patents (CN106631691A) and (CN107056566A) report a method for continuously producing 2-methylpropenol using a noble metal catalyst. SUMMARY

[0005] The present application reasonably designs the catalyst and reasonably optimizes the reaction process, and innovatively improves some deficiencies in the prior art. The present application uses NaY molecular sieve loaded Ni-In bimetallic catalyst to selectively hydrogenate methylpropenal, uses hydrogen as a reducing agent, and uses a fixed bed as a reactor to continuously produce 2-methylpropenol.

[0006] The application takes catalyst as the core driving factor to improve and optimize some existing production problems. The Ni-In bimetallic catalyst involved in the patent has the advantages of low production cost, good activity, high selectivity and strong stability, and has great potential industrial application value.

[0007] According to a first aspect of the application, a method for preparing 2-methylpropenol is provided, comprising the following steps: contacting a catalyst with methylpropenal and hydrogen, and reacting to generate 2-methylpropenol; the catalyst is a NaY molecular sieve loaded Ni-In bimetallic catalyst.

[0008] Optionally, in the catalyst, the loading amount of metal Ni in the catalyst is 3-30 wt.%, and the atomic ratio of Ni to In is 5:1-1:3.

[0009] Optionally, the loading amount of metal Ni is calculated based on the mass of Ni element.

[0010] Optionally, the catalyst is pretreated.

[0011] Optionally, the atmosphere of the pretreatment is selected from at least one of nitrogen, hydrogen, hydrogen-argon mixed gas, air, and carbon dioxide.

[0012] Optionally, the pretreatment temperature is 25-900°C, and the pretreatment time is 2-5h.

[0013] Optionally, the pretreatment temperature is selected from any value or a range value between any two of 25°C, 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, and 900°C.

[0014] Optionally, the pretreatment time is selected from any value or a range value between any two of 2h, 3h, 4h, and 5h.

[0015] Optionally, the molar ratio of hydrogen to methylpropenal is 1:1-20:1.

[0016] Optionally, the mass space velocity of methylpropenal is 0.5-5h -1 .

[0017] Optionally, the reaction pressure is 0.1-5.0MPa.

[0018] Optionally, the reaction temperature is 50-250°C.

[0019] Optionally, the molar ratio of hydrogen to methylpropenal is selected from any value or a range value between any two of 1:1, 5:1, 10:1, 15:1, and 20:1.

[0020] Optionally, the mass space velocity of the methacrolein is selected from any value among 0.5 h -1 , 1 h -1 , 2 h -1 , 3 h -1 , 4 h -1 , 5 h -1 , or a range value between any two of the above.

[0021] Optionally, the temperature of the reaction is selected from any value among 50℃, 100℃, 150℃, 200℃, 250℃, or a range value between any two of the above.

[0022] Optionally, the method for preparing the NaY molecular sieve loaded Ni-In bimetallic catalyst comprises the following steps:

[0023] (1) exchanging a sodium source with a Y molecular sieve to obtain a NaY molecular sieve;

[0024] (2) impregnating the NaY molecular sieve with an aqueous solution containing a nickel source and an indium source, and then drying and calcining to obtain a NaY molecular sieve loaded Ni-In bimetallic catalyst.

[0025] Optionally, the sodium source is selected from at least one of sodium nitrate, sodium chloride, and sodium bromide.

[0026] Optionally, the nickel source is selected from at least one of nickel nitrate, nickel chloride, and nickel sulfate.

[0027] Optionally, the indium source is selected from at least one of indium chloride and indium nitrate.

[0028] Optionally, the loading amount of the metal Ni is 3-30 wt.%, wherein the loading amount of nickel is calculated based on the mass of nickel element.

[0029] Optionally, the atomic ratio of the metal Ni to the metal In is 5:1-1:3.

[0030] Optionally, the aqueous solution further contains a complexing agent.

[0031] Optionally, the complexing agent is selected from at least one of citric acid, acetic acid, glycerol, and ethanedioic acid.

[0032] Optionally, the amount of substance of the complexing agent is 0.5-3 times the total amount of substance of the Ni-In bimetallic cations.

[0033] Optionally, the concentration of sodium ions in the sodium source is 0.1M-1.5M.

[0034] Optionally, the sodium ion concentration in the sodium source is selected from any of 0.1 M, 0.3 M, 0.5 M, 0.7 M, 1 M or a range between any two of the above.

[0035] Optionally, the temperature of the exchange treatment is 25-95°C.

[0036] Optionally, the temperature of the exchange treatment is selected from any of 25°C, 50°C, 75°C, 95°C or a range between any two of the above.

[0037] Optionally, the temperature of the drying is 25-150°C and the time of the drying is 24-48 h.

[0038] Optionally, the temperature of the drying is selected from any of 25°C, 50°C, 75°C, 100°C, 125°C, 150°C or a range between any two of the above.

[0039] Optionally, the time of the drying is selected from any of 24 h, 36 h, 48 h or a range between any two of the above.

[0040] Optionally, the atmosphere of the drying is selected from at least one of air, nitrogen.

[0041] Optionally, the temperature of the calcination is 150-950°C and the time of the calcination is 2-5 h.

[0042] Optionally, the temperature of the calcination is selected from any of 150°C, 250°C, 350°C, 500°C, 700°C, 800°C, 950°C or a range between any two of the above.

[0043] Optionally, the time of the calcination is selected from any of 2 h, 3 h, 4 h, 5 h or a range between any two of the above.

[0044] Optionally, the atmosphere of the calcination is selected from at least one of nitrogen, argon, air, oxygen.

[0045] The present application adopts the following scheme one:

[0046] (1) One or more of sodium nitrate, sodium chloride, sodium bromide is used to configure a solution with a Na ion concentration of 0.1 M-1.5 M, and Y molecular sieve is subjected to Na exchange at a temperature of 25-95°C.

[0047] (2) A certain amount of nickel nitrate, indium chloride or indium nitrate is impregnated into the treated carrier by an equal volume impregnation method, and the loading amount of the metal is 3-25 wt.%.

[0048] (3) The above sample is dried at a temperature of 25-95°C.

[0049] (4) Calcination of the catalyst in one or several of nitrogen, argon, air or oxygen at a temperature between 150 and 950°C.

[0050] (5) Reduction of the calcined catalyst in situ in a fixed bed reactor using hydrogen at a temperature between 300 and 750°C.

[0051] (6) Reaction temperature between 50 and 250°C, space velocity between 0.5 and 5 h -1 -1 between a ratio of hydrogen to methylacrolein between 1 and 20.

[0052] The second solution adopted by the present application is:

[0053] (1) NaY type molecular sieve is used as the carrier of the catalyst.

[0054] (2) Metal nickel and indium salts are loaded onto the carrier by excess impregnation method, aqueous solution of nickel nitrate and indium nitrate is configured with a concentration between 0.1 and 1 M, and the loading amount of the metal is between 3 and 25 wt.%.

[0055] (3) The above sample is dried at a temperature between 25 and 95°C.

[0056] (4) The catalyst is reduced using pure hydrogen at a temperature between 300 and 800°C, treated in an oxygen / nitrogen volume percentage between 0.01 and 85% or in a carbon dioxide atmosphere for 3h.

[0057] (5) The catalyst is used after being pre-reduced.

[0058] (6) The calcined catalyst is shaped, and the catalyst is reduced in situ in a fixed bed reactor using hydrogen at a temperature between 300 and 750°C.

[0059] (7) Reaction temperature between 50 and 250°C, space velocity between 0.5 and 5 h -1 -1 between a ratio of hydrogen to methylacrolein between 1 and 20.

[0060] The third solution adopted by the present application is:

[0061] (1) NaY type molecular sieve is used as the carrier of the catalyst.

[0062] (2) Nickel nitrate, indium chloride or indium nitrate is loaded onto the carrier of the catalyst by one or several complexing agents of citric acid, acetic acid, glycerol, and oxalic acid, the concentration of the metal salt solution is between 0.1 and 0.5 M, and the amount of substance of the complexing agent is 1.2 to 3 times the amount of metal ions.

[0063] (3) drying the above sample in the range of 25-95℃.

[0064] (4) calcining the catalyst in one or several of nitrogen, argon, air or oxygen, at a temperature of 150-950℃.

[0065] (5) using the calcined catalyst after molding, in a fixed bed reactor, in situ treatment of the catalyst using hydrogen, carbon dioxide, hydrogen-argon mixture, air, nitrogen, at a temperature of 300-750℃.

[0066] (6) reaction temperature is between 50-250℃, space velocity is between 0.5-5h -1 , ratio of hydrogen and methylacrolein is between 1-20.

[0067] The fourth scheme adopted by the present application is:

[0068] (1) impregnating a solution of metal salt containing one or several complexing agents of citric acid, acetic acid, glycerol, oxalic acid into NaY molecular sieve, concentration of the solution of metal salt is in the range of 0.1-0.5M, amount of substance of the complexing agent is 1.2-3 times of the amount of metal ion.

[0069] (2) drying the above sample in the range of 25-95℃.

[0070] (3) calcining the catalyst in one or several of nitrogen, argon, air or oxygen, at a temperature of 150-950℃, followed by continuous treatment in one or several of hydrogen, carbon dioxide, air, oxygen, at a temperature of 150-950℃.

[0071] (4) loading into a fixed bed reactor after molding.

[0072] (5) using the calcined catalyst after molding, in a fixed bed reactor, in situ treatment of the catalyst using hydrogen, carbon dioxide, hydrogen-argon mixture, air, nitrogen, at a temperature of 300-750℃.

[0073] (6) reaction temperature is between 50-250℃, space velocity is between 0.5-5h -1 , ratio of hydrogen and methylacrolein is between 1-20.

[0074] The beneficial effects that can be produced by the present application include:

[0075] The application has low production cost, high reaction activity, high selectivity of target product and strong stability; the continuous reactor is used for production, and the reaction is carried out under solvent-free and relatively mild reaction conditions; and the heterogeneous catalyst is convenient for separation from the product.

[0076] The application modifies the metal Ni active site from the geometric and electronic structure by introducing an auxiliary agent, which not only greatly improves the activity and selectivity of the catalyst, but also uses the non-noble metal Ni to replace the noble metal Pt and Pd, effectively reduces the production cost of the catalyst, and provides a basis for realizing large-scale industrial application. The production method adopts a fixed bed reactor, uses methyl propyl aldehyde as a reactant and hydrogen as a reducing agent to realize the continuous production of 2-methyl propyl alcohol under solvent-free conditions. The conversion rate of methyl propyl aldehyde on the Ni-In bimetallic catalyst reaches 98%, the selectivity of 2-methyl propyl alcohol is 90%, and the catalyst shows extremely high stability. DETAILED DESCRIPTION

[0077] The application will be described in detail below in combination with examples, but the application is not limited to these examples.

[0078] Unless otherwise specified, the raw materials in the examples of the application are purchased through commercial channels.

[0079] Example 1

[0080] Y molecular sieve with a silicon-aluminum ratio of 5 is ion exchanged with a 0.1M sodium bromide solution at a temperature of 30°C for 10h, and the above process is repeated 3 times. Then the exchanged molecular sieve is washed in water at 90°C for 3 times. A 0.1M aqueous solution with a metal nickel content of 20wt.% and a metal indium content is prepared by calculation and impregnated on the exchanged NaY molecular sieve. The above sample is dried at 50°C for 24h. Then the dried sample is placed in an oxygen atmosphere and calcined at 800°C for 1h. The prepared catalyst is pressed, crushed, and then 20-40 mesh particles are selected and loaded into a fixed bed reactor. After reduction with hydrogen and argon mixed gas at 750°C for 3h, methyl propyl aldehyde is introduced, and the reaction is carried out at a temperature of 120°C, and the amount-of-substance ratio of hydrogen to reactant is 1:1. Agilent 7890B type gas chromatography is used to analyze the product.

[0081] Example 2

[0082] A solution of nickel nitrate and indium chloride with a loading of 20 wt.% of nickel metal, indium metal, etc. was prepared by calculation to be 0.1 M in water and impregnated onto NaY molecular sieve with a silica-alumina ratio of 5 purchased directly. The sample was left to stand at 25°C for 24 h, and then dried at 50°C for 24 h. The prepared catalyst was loaded into a quartz tube, reduced with pure hydrogen at 700°C for 3 h, and then passivated with air. The prepared catalyst was tabletted, crushed, and then 20-40 mesh particles were selected and loaded into a fixed bed reactor. After reduction with a hydrogen-argon mixture at 750°C for 3 h, the methyl propyl aldehyde reactant was introduced, and the reaction was performed at 120°C, with a molar ratio of hydrogen to reactant of 1:1. The product was analyzed using an Agilent 7890B gas chromatograph.

[0083] Example 3

[0084] A solution of nickel nitrate and indium chloride with a loading of 20 wt.% of nickel metal, indium metal, etc. was prepared by calculation to be 1 M in water, and 150% of the molar amount of metal ions of citric acid was added to the aqueous solution. Then, NaY molecular sieve with a silica-alumina ratio of 5 was added to the solution and stirred vigorously, and the liquid was evaporated at 80°C. The catalyst was calcined at 600°C in an air atmosphere for 3 h, and then treated at 600°C in a carbon dioxide atmosphere for 5 h, and after the catalyst was cooled to room temperature, it was treated with air for 1 h. The prepared catalyst was tabletted, crushed, and then 20-40 mesh particles were selected and loaded into a fixed bed reactor. After reduction with a hydrogen-argon mixture at 750°C for 3 h, the reactant was introduced, and the reaction was performed at 120°C, with a molar ratio of hydrogen to reactant of 1:1. The product was analyzed using an Agilent 7890B gas chromatograph.

[0085] Example 4

[0086] A solution of nickel nitrate and indium chloride with a loading of 20 wt.% of nickel metal, indium metal, etc. was prepared by calculation to be 1 M in water, and 200% of the molar amount of metal ions of citric acid was added to the aqueous solution. Then, NaY molecular sieve with a silica-alumina ratio of 5 was added to the solution and stirred vigorously, and the liquid was evaporated at 60°C. The prepared catalyst was tabletted, crushed, and then 20-40 mesh particles were selected and loaded into a fixed bed reactor. After reduction with a hydrogen-argon mixture at 450°C for 3 h, the reactant was introduced, and the reaction was performed at 120°C, with a molar ratio of hydrogen to reactant of 1:1. The product was analyzed using an Agilent 7890B gas chromatograph.

[0087] Comparative Example

[0088] A solution of nickel nitrate and indium chloride with a content of 20 wt.% of metal nickel, metal indium, etc. was prepared by calculation to be 1M in water, 200% of the molar amount of metal ions of citric acid was added to the aqueous solution, then the SiO2 carrier was added to the above solution and stirred vigorously, and the liquid was evaporated at 60°C. The catalyst was calcined at 600°C in air for 3h, the prepared catalyst was pressed into a sheet, crushed, and then 20-40 mesh particles were selected and loaded into a fixed bed reactor, reduced at 450°C for 3h with hydrogen and argon mixed gas, then the reactant was introduced, and the reaction was carried out at 120°C, the amount-of-substance ratio of hydrogen to the reactant was 1:1. The product was analyzed by Agilent 7890B gas chromatograph.

[0089] The activity evaluation results in the examples in Table 1

[0090]

[0091] As can be seen from Table 1, the NaY molecular sieve supported catalyst has good catalytic activity and selectivity of unsaturated alcohol.

[0092] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed as above, they are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments, and all belong to the scope of the technical solution.

Claims

1. A method for preparing 2-methylpropenol, characterized in that, Includes the following steps: The catalyst was pretreated and then reacted with methacrolein and hydrogen in a fixed-bed reactor to produce 2-methylpropenol. The catalyst is a NaY molecular sieve supported Ni-In bimetallic catalyst, wherein the loading of metallic Ni in the catalyst is 3~30wt%, and the atomic ratio of Ni to In is 5:1~1:3; the reaction is carried out under solvent-free conditions, the reaction temperature is 50~250℃, and the molar ratio of hydrogen to methacrolein is 1:1~20:

1. The pretreatment temperature is 25~900 ℃, and the pretreatment time is 2~5 h.

2. The preparation method according to claim 1, characterized in that, The pretreatment atmosphere is selected from at least one of nitrogen, hydrogen, hydrogen-argon mixture, air, and carbon dioxide.

3. The preparation method according to claim 1, characterized in that, The pretreatment temperature is 600~800 ℃, and the pretreatment time is 2~3 h.

4. The preparation method according to claim 1, characterized in that, The molar ratio of hydrogen to methacrolein is 1:1; The mass hourly space velocity (MSV) of the methacrolein is 0.5–5 h⁻¹. -1 ; The reaction pressure is 0.1~5.0 MPa; The reaction temperature is 90~120 ℃.

5. The preparation method according to claim 1, characterized in that, The preparation method of the NaY molecular sieve-supported Ni-In bimetallic catalyst includes the following steps: (1) The sodium source was exchanged with Y molecular sieve to obtain NaY molecular sieve; (2) The NaY molecular sieve was impregnated with an aqueous solution containing nickel and indium sources, and then dried and calcined to obtain a NaY molecular sieve-supported Ni-In bimetallic catalyst.

6. The preparation method according to claim 5, characterized in that, The sodium source is selected from at least one of sodium nitrate, sodium chloride, and sodium bromide; The nickel source is selected from at least one of nickel nitrate, nickel chloride, and nickel sulfate; The indium source is selected from at least one of indium chloride and indium nitrate.

7. The preparation method according to claim 5, characterized in that, The loading of metallic Ni is 20 wt.%, wherein the mass of metallic Ni is based on the mass of nickel. The atomic ratio of metallic Ni to metallic In is 1:

1.

8. The preparation method according to claim 5, characterized in that, The aqueous solution also contains a complexing agent; The complexing agent is selected from at least one of citric acid, acetic acid, glycerol, and oxalic acid; The amount of the complexing agent is 0.5 to 3 times the total amount of Ni-In bimetallic ions.

9. The preparation method according to claim 5, characterized in that, The sodium ion concentration in the sodium source is 0.1M~1.5M; The temperature for the exchange process is 25~95℃.

10. The preparation method according to claim 5, characterized in that, The drying temperature is 25~150 ℃, and the drying time is 24~48 h; The calcination temperature is 150~950 ℃, and the calcination time is 2~5 h; The roasting atmosphere is selected from at least one of nitrogen, argon, air, and oxygen.

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