Reaction device and method for preparing mandelic acid compounds

Abstract

The invention discloses a reaction device for preparing mandelic acid compounds. The reaction device comprises a first microchannel heat exchanger, a second microchannel heat exchanger, a first microchannel reactor, a second microchannel reactor, a product collector, a first liquid metering pump, a second liquid metering pump, a third liquid metering pump and a fourth liquid metering pump, whereinan outlet of the first liquid metering pump is connected with a first inlet of the first microchannel heat exchanger, an outlet of the second liquid metering pump is connected with a second inlet ofthe first microchannel heat exchanger, an outlet of the first microchannel heat exchanger is connected with a first inlet of the first microchannel reactor, a second inlet of the first microchannel reactor is connected with an outlet of the second microchannel heat exchanger, an inlet of the second microchannel heat exchanger is connected with an outlet of the third liquid metering pump, an outletof the first microchannel reactor is connected with a first inlet of the second microchannel reactor, a second inlet of the second microchannel reactor is connected with an outlet of the fourth liquid metering pump, and an outlet of the second microchannel reactor is connected with the product collector. The invention further discloses a method for preparing mandelic acid compounds by using the device. The reaction device and the method have the advantages of high efficiency, energy saving and environment protection.

Description

technical field [0001] The invention relates to the technical field of mandelic acid compounds, in particular to a reaction device and a method for preparing mandelic acid compounds. Background technique [0002] Mandelic acid compounds are aromatic compounds containing a -CHOH-COOH group on the benzene ring. Generally, substituted aromatic hydrocarbons can react with glyoxylic acid under alkaline conditions to generate mandelic acid compound salts, and then adjust the pH of the solution with acid value, so that mandelic acid compound is precipitated, and the chemical reaction process that takes place is as follows: [0003] [0004] One of the technical difficulties of this reaction lies in the fact that the condensation yields are low and the product selectivity is not high. Take R1=OH as an example, except that the target product p-hydroxymandelic acid, the product also reacts to produce 5 to 10% isomer o-hydroxymandelic acid, and 10 to 15% dimandelic acid (after gene...

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Problems solved by technology

However, this reactor has some disadvantages, such as poor mixing effect of materials, easy stratification or crystallization, which leads to problems such as stratification of reaction liquid and crystallization of materials in long plug-flow tube reactors, which leads to the implementation of Unsatisfactory effect

Although CN101835734A proposes to change the mixing effect in the reactor by adding fillers in the pipeline, it still has not achieved obvious technical effects

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