Method for synthesizing crotonic acid by oxidizing croton aldehyde selectively

A barium oxide, selective technology, applied in chemical instruments and methods, preparation of organic compounds, chemical recovery, etc., can solve the problems of low catalytic activity, complex reaction process, easy decomposition, etc., to achieve high catalytic oxidation activity, selective High-performance, easy-to-prepare effect

Inactive Publication Date: 2007-07-25
SINOPEC YANGZI PETROCHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

British patent (GB595170) uses manganese, copper, cobalt acetate or other carboxylate as catalyst, acetone is solvent, and the yield of crotonic acid is 57.51%. The catalytic activity of this type of catalyst is not high, and dissolves in the reaction system In the process, it is difficult to separate from the reaction products and cannot be recycled
[0005] U.S. Patent (US4097523) uses thallium organic acids or inorganic acid salts such as thallium triacetate, thallium acetate, thallium acetylacetonate, thallium bromide, thallium nitrate, etc. as catalysts. The conversion rate of crotonaldehyde is 75%. The choice of crotonic acid The specificity is 75%, but the cost of the thallium salt catalyst is high, and the thallium salt catalyst is highly toxic
[0006] U.S. Patent (US2577829) adopts peroxide catalysts such as hydrogen peroxide, benzoyl peroxide, ammonium persulfate, potassium persulfate or sodium perborate, the conversion rate of crotonaldehyde is 85%, the selectivity of crotonic acid is 84.71%, and croton The selectivity of the acid is high, but the catalyst peroxide is unstable, easy to decompose, and the safety of the production process is poor
[0007] Chinese patent (CN021386992) is catalyst with metal silver powder, in oxidation tower, becomes the technique of crotonic acid with air oxidation crotonaldehyde, the yield of crotonic acid is 75%, this catalyst can be recycled, but catalyst cost is high, and catalyst is in oxidation tower Difficult to disperse
[0008] Lin Jing et al. (Journal of Xiamen University, 1993, 32 (6): 745~748) used the Schiffer base complex catalyst of cobalt, and the yield of crotonic acid was 65.5%, but the preparation process of the catalyst was complicated, and the yield of crotonic acid rate is not high
Cai Zhebin et al. (Journal of Hubei Agricultural College, 2000, 20 (4): 374~376) use metal oxide / adsorption resin catalyst, the oxidation reaction of crotonaldehyde is carried out in lye, and the product is hydrolyzed with hydrochloric acid to obtain crotonic acid, crotonic acid The yield is 87.1%, but the reaction process is complicated, using lye and hydrochloric acid, which is highly corrosive to equipment, and forms waste water containing acid and alkali, which is harmful to the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Put 65g of activated carbon into 280mL of nitric acid solution with a concentration of 4mol / L, heat and stir at 90°C for 1h, let it stand for 12 hours, wash it with deionized water until neutral, and bake it in an oven at 120°C for 12 hours. Prepare 150 mL of phosphomolybdic acid methanol solution with a concentration of 0.1 g / mL, add 60 g of pretreated activated carbon, stir and reflux at 55 °C for 6 hours, let stand for 12 hours, evaporate excess methanol in a water bath, and place in an oven Dry at 120° C. for 24 hours to prepare an activated carbon-immobilized phosphomolybdic acid catalyst with a solid loading capacity of 20%, which is placed in a desiccator for subsequent use.

Embodiment 2

[0024] 20gSiO 2 Dry at 120°C for 5 hours, then burn at 500°C for 4 hours, cool, and place in a desiccator for later use. Prepare 50 mL of phosphomolybdic acid ethanol solution with a concentration of 0.3 g / mL, and then add 15 g of pretreated SiO 2 , stirred and refluxed at 55°C for 6 hours, stood still for 12 hours, evaporated excess methanol in a water bath, and then baked in an oven at 120°C for 24 hours to obtain SiO with a solid loading of 50%. 2 The immobilized phosphomolybdic acid catalyst is placed in a desiccator for standby use.

Embodiment 3

[0026] 50g γ-Al 2 o 3 Burn at 500°C for 5 hours, cool, and place in a desiccator for later use. Prepare 100 mL of phosphomolybdic acid acetone solution with a concentration of 0.05 g / mL, and then add 45 g of pretreated γ-Al 2 o 3 , stirred and refluxed at 55°C for 6 hours, left to stand for 12 hours, evaporated excess methanol in a water bath, and then baked in an oven at 120°C for 24 hours to obtain activated carbon-immobilized phosphomolybdic acid with a solid loading of 10%. Catalyst, placed in a desiccator for later use.

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PUM

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Abstract

This invention relates to a method for synthesizing crotonic acid by selective oxidation of crotonaldehyde. The method adopts crotonaldehyde as the raw material, acetone, acetic acid, benzene or toluene as the solvent, phosphomolybdic acid as the main catalyst, and V2O5 as the cocatalyst, and reacts at 30-100 deg.C and 0.3-0.9 MPa in the presence of O2 to obtain crotonic acid. Phosphomolybdic acid can be supported by such carriers as active carbon, SiO2, gamma-Al2O3 or molecular sieve. Therefore, the catalyst can be separated from the reaction solution by filtration, and dried in air at 120 deg.C for recycling. The supported catalyst has such advantages as simple preparation, high catalytic activity, high selectivity, and high stability, and can be used repeatedly.

Description

technical field [0001] The invention relates to a synthesis method of crotonic acid, in particular to a catalyst for selectively oxidizing crotonaldehyde to synthesize crotonic acid and its application. Background technique [0002] Crotonic acid is also known as 2-butenoic acid, β-methacrylic acid, and ethylene acetic acid. It is an important unsaturated fatty acid with unsaturated double bonds and carboxyl groups in its molecule. It has strong reactivity and is mainly used in Used in synthetic insecticides, resins, coatings, plasticizers, fungicides, fiber treatment agents, surfactants, adhesives, etc. [0003] Crotonic acid is obtained by one-step oxidation of crotonaldehyde with air or oxygen. Since crotonaldehyde contains unsaturated carbon-carbon double bonds, it is necessary to selectively oxidize the aldehyde group without destroying the double bonds. Therefore, it is necessary to prepare a catalyst with high selective oxidation catalytic activity and use a suitable ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/235C07C57/08B01J27/199
CPCY02P20/584
Inventor 乔旭李维新汤吉海温从科崔咪芬秦建元赵宝明
Owner SINOPEC YANGZI PETROCHEM
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