Method for performing aldol condensation reaction in micro-channel reactor

Abstract

The invention relates to a method for performing an aldol condensation reaction in a micro-channel reactor. The aldol condensation reaction is performed in the micro-channel reactor under the action of a catalyst at 60 to 170 DEG C and 0 to 5 MPa in the situation that alpha-H aldehyde ketone and other aldoketones in molecules are in the molar ratio of 0.8-1.2:1. According to the aldol condensationreaction involved in a process provided by the invention, the reaction time is shortened by thousands of times; the raw material conversion rate and the product selectivity are improved by 15 percentat least. The process provided by the invention can realize instantaneous uniform mixing; the equivalence ratio of materials in a reaction process is reduced; the using amount of a catalyst in a reaction process is reduced; Cannizzaro side reactions and polymerization reactions are reduced. The process provided by the invention also reduces the use of some additional solvents so as to reduce theproduction cost; the process provided by the invention also improves the safety of a reaction process, so that the types of reactions are safer and more environment-friendly; meanwhile, the micro-channel reactor used by the process provided by the invention is small in occupied area and high in capacity, so that the production efficiency and the production capacity are greatly improved.

Description

technical field [0001] The invention relates to a method for carrying out aldol condensation reaction in a microchannel reactor. Specifically, in a microchannel reactor, aldehydes and ketones containing α-H are used in the microchannel reactor to carry out aldol condensation reactions with other aldehydes and ketones to generate β- Hydroxyaldehydes or β-hydroxy ketones or further dehydration products α, β-unsaturated aldehydes and ketones belong to the field of aldol condensation reaction synthesis. Background technique [0002] The aldol condensation reaction is a condensation reaction between aldehydes and ketones with α-H and other aldehydes and ketones under catalyst conditions; through the aldol condensation reaction, new carbon-carbon bonds can be formed in the molecule to increase the carbon chain, and any α - β-hydroxyl aldehydes and ketones with hydrogen atoms on the carbon, because the α-hydrogen is relatively active, they are easy to lose a molecule of water, and ...

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Problems solved by technology

[0004] There are some problems in the aldol condensation reaction of conventional laboratory equipment and reactors, such as: 1) During the operation, it will involve contact with toxic substances such as aldehydes and ketones, especially formaldehyde is used more and is more toxic; 2) During the reaction process The amount of catalyst used is large, causing waste and increasing the three wastes; 3) The selectivity of stereoselective and regioselective reactions is poor, especially the reaction of cross-aldol condensation of raw materials containing multiple α-H, the selectivity of products Worse; 4) usually all need to increase the equivalence ratio of a kind of raw material in conventional reaction, to guarantee another raw material reaction fully, excessive raw material just needs loaded down with trivial details recovery process; 5) does not contain α-H under alkaline condition Aldehydes are prone to Cannizzaro side reactions; 6) If there are multiple phases in the reaction, the conventional reaction is not stirred uniformly, and the mass transfer of the raw materials at the phase interface cannot be carried out well; 7) It is difficult to obtain the dehydrated product state after the reaction is completed control, and the dehydrated product obtained in the conventional reaction is easy to polymerize to form a polymer

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