Method for synthesizing butenoic acid from carbon dioxide and propylene

Abstract

The invention relates to the technical field of butenoic acid synthesis, in particular to a method for synthesizing butenoic acid from carbon dioxide and propylene. The method at least comprises the following steps: (1) adding a catalyst and an organic solvent into a reaction kettle, introducing nitrogen to replace gas in the reaction kettle, and stirring to obtain a mixed solution; (2) replacing gas in the reaction kettle with carbon dioxide, adding propylene, controlling the pressure in the reaction kettle at 3-5 MPa, and carrying out heating reaction to obtain a reaction solution; (3) after the reaction is finished and the temperature in the kettle is reduced to 30-40 DEG C, replacing gas in the reaction kettle with nitrogen, and filtering the reaction liquid to obtain filtrate; and (4) carrying out reduced pressure distillation on the filtrate twice to obtain the product. The butenoic acid synthesis method provided by the invention can efficiently catalyze coupling of propylene and carbon dioxide and significantly improve the yield and purity of butenoic acid, the highest yield of butenoic acid can reach 92.6%, the yield of butenoic acid is obviously improved compared with that of butenoic acid produced by a traditional butenal oxidation reaction, and the method has good practical value.

Description

Technical Field

[0001] The invention relates to the technical field of crotonic acid synthesis, and in particular to a method for synthesizing crotonic acid from carbon dioxide and propylene. Background Art

[0002] Carbon dioxide not only exists as a greenhouse gas, but also is a low-cost, vital and effective carbon resource. It is widely available, safe, non-toxic, environmentally friendly and non-flammable. It can be used to manufacture organic chemicals, materials, sugars and fuels, etc., and is regarded as a promising basic raw material for organic synthesis. However, because the carbon atoms in the carbon dioxide molecule are in their highest oxidation state and the entire molecule is thermodynamically and kinetically inert, people have been exploring new reaction pathways and catalytic systems to achieve effective resource utilization of carbon dioxide.

[0003] Crotonic acid is a high value-added organic chemical intermediate raw material, which is widely used in many fields such as drug manufacturing, resin production, fungicide preparation, surface coatings and plasticizers. In view of the rich advantages of my country's propylene production capacity, the development of a novel and efficient catalytic system for the preparation of crotonic acid products has great practical significance.

[0004] Chinese patent CN116143606A discloses a process for synthesizing acrylic acid with reduced by-products. The raw material propylene is first diluted with carbon dioxide and then reacted with oxygen in an oxygen source, which can reduce the occurrence of side reactions and increase the yield of the target product. However, the synthesis process in the above technology is complicated, and the conversion rate and yield of the raw materials need to be further improved. Summary of the invention

[0005] In order to solve the problems in the prior art, the present invention provides a method for synthesizing crotonic acid from carbon dioxide and propylene, which comprises at least the following steps:

[0006] (1) adding a catalyst and an organic solvent into a reaction kettle, introducing nitrogen to replace the gas in the reaction kettle, and then stirring to obtain a mixed liquid;

[0007] (2) replacing the gas in the reactor with carbon dioxide and then adding propylene, while controlling the pressure in the reactor to 3-5 MPa and then heating the reactor to obtain a reaction liquid;

[0008] (3) After the reaction is completed and the temperature in the reactor drops to 30-40° C., nitrogen is used to replace the gas in the reactor, and the reaction liquid is filtered to obtain a filtrate;

[0009] (4) The filtrate is distilled under reduced pressure twice to obtain the product.

[0010] In one embodiment, the catalyst includes a main catalyst and a co-catalyst.

[0011] In one embodiment, the mass ratio of the main catalyst to the co-catalyst is (8-11): 1. Examples include 8:1, 9:1, 10:1, and 11:1.

[0012] In one embodiment, the main catalyst is selected from any one of a monometallic catalyst and a bimetallic catalyst.

[0013] In one embodiment, the bimetallic catalyst includes a combination of one or more of a titanium-based bimetallic catalyst, a cobalt-based bimetallic catalyst, a nickel-based bimetallic catalyst, a rhodium-based bimetallic catalyst, and a palladium-based bimetallic catalyst.

[0014] In a preferred embodiment, the bimetallic catalyst is a rhodium-based bimetallic catalyst. Preferably, the rhodium-based bimetallic catalyst is a rhodium-aluminum bimetallic catalyst.

[0015] In one embodiment, the co-catalyst comprises a Lewis acid.

[0016] In a preferred embodiment, the Lewis acid includes any one of aluminum trichloride, titanium tetrachloride, boron trifluoride, ferric chloride, and zinc dichloride.

[0017] In a more preferred embodiment, the Lewis acid is titanium tetrachloride.

[0018] In one embodiment, the organic solvent includes any one of dimethylformamide, dimethyl, 1.3-dimethyl-2-imidazolidinone, N-cyclohexylpyrrolidone, methylcyclohexane, N-ethylpyrrolidone, N-methylpyrrolidone, and tetrahydrofuran.

[0019] In a preferred embodiment, the organic solvent is dimethylformamide.

[0020] In one embodiment, the mass ratio of the organic solvent to the catalyst is (500-1000): 1, which may be 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1.

[0021] In one embodiment, the stirring time in step (1) is 0.5-1 h, which can be 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, or 1 h.

[0022] In one embodiment, the stirring speed in step (1) is 400-500 r / min.

[0023] In one embodiment, the number of substitutions in step (1) is 3-5 times, which may be 3 times, 4 times, or 5 times.

[0024] In one embodiment, the conditions for the temperature-raising reaction in step (2) are: stirring speed of 1000-1500 r / min; temperature of 80-150° C.; and reaction time of 10-30 h.

[0025] In a preferred embodiment, the conditions for the temperature-raising reaction in step (2) are: stirring speed of 1000 r / min; temperature of 100° C.; and reaction time of 20 h.

[0026] In one embodiment, during the temperature increase reaction in step (2), carbon dioxide is continuously introduced to maintain the reaction pressure at 3-5 MPa, which may be 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, or 5 MPa.

[0027] In one embodiment, the step (4) is specifically as follows: after the filtrate is subjected to a first vacuum distillation, the organic solvent is recovered from the top, and the crude product of butenoic acid is collected from the bottom; and after adding an inhibitor to the crude product of butenoic acid, a second vacuum distillation is performed to obtain the product.

[0028] In the present invention, the catalyst is recovered by filtering in step (3), and the organic solvent is recovered in step (4), thereby achieving the recyclable reuse of the catalyst and the organic solvent.

[0029] In one embodiment, the conditions of the first reduced pressure distillation are: pressure of -0.095 MPa and temperature of 90-100° C. Preferably, the pressure is -0.095 MPa and the temperature is 93° C.

[0030] In one embodiment, the conditions for the second reduced pressure distillation are: pressure of -0.095 MPa and temperature of 140-160° C. Preferably, the pressure is -0.095 MPa and the temperature is 150° C.

[0031] In one embodiment, the polymerization inhibitor includes one or more combinations of tert-butylcatechol, hydroquinone, methylhydroquinone, and p-benzoquinone. Preferably, the polymerization inhibitor is tert-butylcatechol.

[0032] In one embodiment, the mass ratio of the polymerization inhibitor to the crude crotonic acid product is (1-5): 100000, which can be exemplified as 1: 100000, 2: 100000, 3: 100000, 4: 100000, and 5: 100000.

[0033] Beneficial Effects

[0034] 1. The method for synthesizing crotonic acid provided by the present invention has simple process and high production efficiency. A rhodium-aluminum bimetallic catalyst is used as the main catalyst, and a small amount of titanium tetrachloride is added as a co-catalyst to catalyze the reaction of propylene and carbon dioxide to synthesize crotonic acid, and then two vacuum distillations are performed to finally obtain crotonic acid.

[0035] 2. The present invention adopts a specific rhodium-based bimetallic catalyst and a catalytic promoter, which can efficiently catalyze the coupling of propylene and carbon dioxide and significantly improve the yield and purity of butenoic acid. The yield of butenoic acid can reach up to 92.6%, which is significantly improved compared with the yield of butenoic acid produced by the traditional butenoaldehyde oxidation reaction.

[0036] 3. The method for synthesizing crotonic acid from carbon dioxide and propylene provided by the present invention has the characteristics of easy separation, the catalyst and the organic solvent can be recycled and reused, and the crotonic acid has a large boiling point difference with the by-products and the inhibitor, which is convenient for separation and purification.

[0037] 4. The specific rhodium-based bimetallic catalyst used in the present invention has good cycle stability and can still maintain a relatively high yield of crotonic acid after being repeatedly used ten times. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods in the examples without specifying specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without specifying the manufacturer are all conventional products that can be purchased commercially.

[0039] Example 1

[0040] This embodiment provides a method for synthesizing crotonic acid from carbon dioxide and propylene, comprising the following steps:

[0041] (1) 0.5625 g of catalyst and 281.25 g of organic solvent were added to a reactor, nitrogen was introduced to replace the gas in the reactor, and the mixture was stirred at 400 r / min for 0.5 h to obtain a mixed solution;

[0042] (2) replacing the gas in the reactor with carbon dioxide, adding 84 g of propylene, and controlling the pressure in the reactor to 3 MPa, and then heating the reactor to obtain a reaction solution; during the heating reaction, the carbon dioxide was continuously charged to maintain the reaction pressure at 3 MPa;

[0043] (3) After the reaction is completed and the temperature in the reactor drops to 30° C., nitrogen is used to replace the gas in the reactor, and the reaction liquid is filtered to obtain a filtrate;

[0044] (4) After the filtrate is subjected to the first vacuum distillation, the organic solvent is recovered from the top, and the crude product of crotonic acid is collected from the bottom; after adding a polymerization inhibitor to the crude product of crotonic acid, a second vacuum distillation is performed to obtain the product.

[0045] The catalyst comprises a main catalyst and a co-catalyst, and the mass ratio of the main catalyst to the co-catalyst is 8:1.

[0046] The main catalyst is a rhodium-aluminum bimetallic catalyst.

[0047] The co-catalyst is titanium tetrachloride.

[0048] The polymerization inhibitor is tert-butyl catechol, and the mass ratio of the polymerization inhibitor to the crude product of crotonic acid is 3:100000.

[0049] The number of substitutions in step (1) is 5.

[0050] The conditions for the temperature-raising reaction in step (2) are: stirring speed of 1000 r / min; temperature of 100° C.; and reaction time of 20 h.

[0051] The conditions of the first reduced pressure distillation are: pressure of -0.095 MPa and temperature of 93°C.

[0052] The conditions of the second reduced pressure distillation are: pressure of -0.095 MPa and temperature of 150°C.

[0053] The purity of the crotonic acid obtained in this example is 99.7%, and the yield of crotonic acid is 90.2%.

[0054] Example 2

[0055] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that the conditions for the temperature-raising reaction in step (2) are as follows: the stirring speed is 1000 r / min; the temperature is 120° C.; and the reaction time is 20 h.

[0056] The yield of crotonic acid obtained in this example is 89.5%.

[0057] Example 3

[0058] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that the conditions for the temperature-raising reaction in step (2) are as follows: the stirring speed is 1000 r / min; the temperature is 140° C.; and the reaction time is 20 h.

[0059] The yield of crotonic acid obtained in this example is 82.8%.

[0060] Example 4

[0061] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that the conditions for the temperature-raising reaction in step (2) are as follows: the stirring speed is 1000 r / min; the temperature is 80° C.; and the reaction time is 20 h.

[0062] The yield of crotonic acid obtained in this example is 83%.

[0063] Example 5

[0064] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and the pressure in the reactor is controlled at 3.5 MPa, and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 3.5 MPa.

[0065] The yield of crotonic acid obtained in this example is 91.1%.

[0066] Example 6

[0067] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and at the same time, the pressure in the reactor is controlled at 4 MPa and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0068] The yield of crotonic acid obtained in this example is 92.6%.

[0069] Example 7

[0070] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and the pressure in the reactor is controlled at 4.5 MPa, and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4.5 MPa.

[0071] The yield of crotonic acid obtained in this example is 91.3%.

[0072] Example 8

[0073] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and at the same time, the pressure in the reactor is controlled at 5 MPa and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 5 MPa.

[0074] The yield of crotonic acid obtained in this example is 90.5%.

[0075] Example 9

[0076] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and at the same time, the pressure in the reactor is controlled at 4 MPa and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0077] The mass ratio of the main catalyst to the co-catalyst is 9:1.

[0078] The yield of crotonic acid obtained in this example is 92.6%.

[0079] After the catalyst recovered by filtration in step (3) of this example was reacted repeatedly for 9 times, the average yield of crotonic acid was 89.3%.

[0080] Example 10

[0081] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and at the same time, the pressure in the reactor is controlled at 4 MPa and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0082] The mass ratio of the main catalyst to the co-catalyst is 10:1.

[0083] The yield of crotonic acid obtained in this example is 86.5%.

[0084] Embodiment 11

[0085] The specific implementation method of this embodiment is the same as that of Embodiment 1, except that, step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and at the same time, the pressure in the reactor is controlled at 4 MPa and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0086] The mass ratio of the main catalyst to the co-catalyst is 10:1.

[0087] The yield of crotonic acid obtained in this example is 86.5%.

[0088] Example 12

[0089] The specific implementation of this embodiment is the same as that of Example 9, except that the mass ratio of the inhibitor to the crude product of crotonic acid is 1:100000.

[0090] The yield of crotonic acid obtained in this example is 87%.

[0091] Example 13

[0092] The specific implementation method of this embodiment is the same as that of Example 9, except that the mass ratio of the inhibitor to the crude product of crotonic acid is 5:100000.

[0093] The yield of crotonic acid obtained in this example is 92.5%.

[0094] Comparative Example 1

[0095] The specific implementation method of this comparative example is the same as that of Example 1, except that the conditions for the temperature-raising reaction in step (2) are: a stirring speed of 1000 r / min; a temperature of 160° C.; and a reaction time of 20 h.

[0096] The yield of crotonic acid obtained in this comparative example was 75.6%.

[0097] Comparative Example 2

[0098] The specific implementation method of this comparative example is the same as that of Example 1, except that step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and the pressure in the reactor is controlled at 4 MPa, and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0099] The mass ratio of the main catalyst to the co-catalyst is 12:1.

[0100] The yield of crotonic acid obtained in this comparative example was 73.5%.

[0101] Comparative Example 3

[0102] The specific implementation method of this comparative example is the same as that of Example 1, except that step (2) is as follows: after replacing the gas in the reactor with carbon dioxide, 84 g of propylene is added, and the pressure in the reactor is controlled at 4 MPa, and then the temperature is increased to react to obtain a reaction liquid; during the temperature reaction, carbon dioxide is controlled to be continuously charged to maintain the reaction pressure at 4 MPa.

[0103] The catalyst is a rhodium-aluminum bimetallic catalyst.

[0104] The yield of crotonic acid obtained in this comparative example was 79.2%.

Claims

1. A method for synthesizing crotonic acid from carbon dioxide and propylene, characterized in that: At least the following steps are included: (1) adding a catalyst and an organic solvent into a reaction kettle, introducing nitrogen to replace the gas in the reaction kettle, and then stirring to obtain a mixed liquid; (2) replacing the gas in the reactor with carbon dioxide and then adding propylene, while controlling the pressure in the reactor to 3-5 MPa and then heating the reactor to obtain a reaction liquid; (3) After the reaction is completed and the temperature in the reactor drops to 30-40° C., nitrogen is used to replace the gas in the reactor, and the reaction liquid is filtered to obtain a filtrate; (4) The filtrate is distilled under reduced pressure twice to obtain the product.

2. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 1, characterized in that: The catalyst includes a main catalyst and a co-catalyst.

3. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 2, characterized in that: The mass ratio of the main catalyst to the co-catalyst is (8-11):

1.

4. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 2 or 3, characterized in that: The main catalyst is selected from any one of a monometallic catalyst and a bimetallic catalyst.

5. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 4, characterized in that: The bimetallic catalyst includes a combination of one or more of a titanium-based bimetallic catalyst, a cobalt-based bimetallic catalyst, a nickel-based bimetallic catalyst, a rhodium-based bimetallic catalyst, and a palladium-based bimetallic catalyst.

6. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 2 or 3, characterized in that: The co-catalyst includes a Lewis acid.

7. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 1, characterized in that: The organic solvent includes any one of dimethylformamide, dimethyl, 1,3-dimethyl-2-imidazolidinone, N-cyclohexylpyrrolidone, methylcyclohexane, N-ethylpyrrolidone, N-methylpyrrolidone and tetrahydrofuran.

8. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 7, characterized in that: The mass ratio of the organic solvent to the catalyst is (500-1000):

1.

9. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 1, characterized in that: The step (4) specifically comprises: recovering the organic solvent from the top of the filtrate after the first vacuum distillation, and collecting the crude product of crotonic acid from the bottom; and adding a polymerization inhibitor to the crude product of crotonic acid and performing a second vacuum distillation to obtain the product.

10. The method for synthesizing crotonic acid from carbon dioxide and propylene according to claim 9, characterized in that: The mass ratio of the polymerization inhibitor to the crude product of crotonic acid is (1-5):100000.