A kind of azeotropic rectification heat coupled polyoxymethylene dimethyl ether synthesis reaction system

Abstract

The invention discloses an azeotropic distillation thermal coupling poly-methoxy-dimethyl ether synthetic reaction system. Formaldehyde in a raw material formaldehyde aqueous solution and methylal synthesize DMMN (n is equal to 2 to 8) in an azeotropic catalystic distillation reactor; water in the raw material formaldehyde aqueous solution and methylal are subjected to reaction to generate methanol and formaldehyde, and the methylal and the methanol are azeotropic in a certain ratio; the raw material formaldehyde aqueous solution and the generated M2 product form azeotropic composition; one-step dehydration is realized by the reaction of decomposing the methylal at high temperature to consume water to generate methanol with relatively low boiling point; the M2 is returned by using a subsequent separation unit to adjust the azeotropic composition of the M2 and the water to perform further dehydration; part of materials are produced through gas phase from the proper position in a distillation section by introducing a thermal coupling principle to separate the azeotropic composition of the M2 and the water from the reaction system; the harmful water component in the reaction system isefficiently consumed, target reaction is efficiently promoted and more DMMN products are generated. The problem of low product yield caused by existence of a large amount of water in the conventionalproduction process of the formaldehyde aqueous solution is solved.

Description

technical field [0001] The invention relates to the technical field of synthesis of polyoxymethylene dimethyl ether and product separation, in particular to an azeotropic rectification thermally coupled polyoxymethylene dimethyl ether synthesis reaction system. Background technique [0002] At present, polyoxymethylene dimethyl ether is mostly formed by the reaction of methylal / methanol and formaldehyde (formaldehyde can come from formaldehyde aqueous solution / paraformaldehyde / paraformaldehyde) under the catalysis of an acidic catalyst. [0003] The choice of reaction raw materials not only directly determines the construction cost, raw material consumption and energy consumption. It also affects the complexity of the process and has very different requirements for operations. The use of polypolymerization and tripolymerization as raw materials for production faces the problems of high raw material costs, complex equipment and process, and high energy consumption. In the f...

AI Technical Summary

Problems solved by technology

[0012] The technical problem to be solved in the present invention is to overcome the problem of low product yield due to the existence of a large amount of water in the existing process of producing polyoxymethylene dimethyl ether with formaldehyde aqueous solution, and to provide a thermally coupled reaction system for azeotropic rectification

Images