Method for industrially producing crotonic acid by adopting microchannel reactor

Abstract

The invention discloses a method for industrially producing crotonic acid by adopting a microchannel reactor, and relates to the technical field of chemical production of crotonic acid. A silicon carbide ceramic plate type micro-channel reactor is adopted, crotonaldehyde, a catalyst and an initiator are mixed and preheated according to a certain proportion, meanwhile, a gaseous oxidizing agent is introduced into the reactor, when the pressure in the reactor reaches 0.6-2.0 MPa, the mixed solution is injected into the micro-channel reactor through a metering pump for a reaction, the retention time of the materials is 8-30 min, and then the crotonaldehyde is obtained. The crotonic acid finished product can be obtained through the processes of material oxidation, crude product crystallization, crude product fine washing, fine product crystallization, drying granulation, catalyst regeneration and the like, the one-time yield of the product can reach 60%, and the mechanical application yield can reach 95%. The method has the advantages of good mass transfer and heat transfer effects, short oxidation reaction time, high product yield, high safety degree, few process steps, recyclable catalyst, low production cost, recyclable raw materials in each step, high reaction speed, low wastewater energy consumption and the like.

Description

technical field [0001] The invention relates to the technical field of chemical production of crotonic acid, in particular to a method for industrially producing crotonic acid using a microchannel reactor. Background technique [0002] Crotonic acid is an important chemical intermediate, which is widely used in many fields such as medicine, pesticides, dyes, spices, photosensitive chemicals, polymer catalysts, and biodiesel additives. [0003] The existing crotonic acid preparation methods are mainly divided into two types: non-catalytic oxidation production and catalytic oxidation production. (1) Non-catalytic oxidation production: the patent texts of Publication Nos. CN1396148 and CN101979371A respectively disclose the method of preparing crotonic acid without any catalyst oxidation. Using the data of the examples in the patent document of Publication No. CN1396148, it is found that the utilization rate of crotonaldehyde is only About 20±2%. (2) Catalytic oxidation produ...

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Problems solved by technology

(1) Non-catalytic oxidation production: the patent texts of Publication Nos. CN1396148 and CN101979371A respectively disclose the method of preparing crotonic acid without any catalyst oxidation. Using the data of the examples in the patent document of Publication No. CN1396148, it is found that the utilization rate of crotonaldehyde is only About 20±2%

(2) Catalytic oxidation production: The catalyst preparation process in the patent document of Publication No. CN101003473A is cumbersome; the catalyst used in CA595170A is dissolved in solvent and cannot be recovered; the method disclosed in CN101003472A involves the problem of heavy metal pollution; the catalytic oxidation method mentioned in other relevant public materials to produce croton Acid also has disadvantages such as high production cost, harsh production conditions, complicated follow-up treatment process, toxic solvent, and low product yield, which seriously restrict the development of production technology.

[0006] At present, there are no relevant papers and patent reports on the production of crotonic acid by oxidation of crotonaldehyde using a microchannel reactor in China, and this field is still in a blank stage.

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