Device and method for preparing 2, 5-furandicarboxylic acid from hexose diacid (hexose diacid salt) by coupling dehydration cyclization reaction and azeotropic distillation dehydration

Abstract

The invention discloses a device and a method for preparing 2, 5-furandicarboxylic acid from hexose diacid (hexose diacid salt) by coupling dehydration cyclization reaction and azeotropic distillationdehydration. The device integrates dehydration cyclization reaction and azeotropic distillation dehydration. The method comprises the following steps of 1) opening a reaction kettle for stirring anda reaction kettle jacket for heating steam, sequentially adding a reaction solvent, hexose diacid (salt), a catalyst and an entrainer into a dehydration cyclization reaction kettle, enabling water generated by reaction and the entrainer to form azeotrope, enabling the azeotrope to slip out of the tower top and reacting for 15-48h at the reaction temperature of 100-130 DEG C, and 2) after the reaction is finished, recovering the entrainer from a phase splitter, then cooling, neutralizing with alkali, recovering the reaction solvent by reduced pressure distillation, and then crystallizing and recrystallizing to obtain the 2, 5-furandicarboxylic acid product. By coupling azeotropic distillation, water generated in the reaction is removed in time, so that side reactions are reduced, and the yield of the product 2, 5-furandicarboxylic acid is greatly increased.

Description

technical field [0001] The invention belongs to the field of reactive distillation in the chemical industry, and in particular relates to a device and method for preparing 2,5-furandicarboxylic acid from hexaric acid (salt) coupled with dehydration ring closure reaction and azeotropic distillation for water removal. Background technique [0002] With the increasing uncertainties of fossil resources and people's emphasis on environmental pollution, renewable biomass has attracted more and more attention as an alternative raw material in the chemical industry. Among them, biomass-based 2,5-furandicarboxylic acid (2,5-Furandicarboxylic acid, referred to as: 2,5-FDCA, CAS No.: 3238-40-2) is similar to petroleum-based terephthalic acid in the Polymers, medicines, fine chemicals, solvents and other fields have broad application prospects. In 2004, it was listed as one of the twelve biomass-based platform compounds by the U.S. Department of Energy. Its structural formula is as foll...

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Problems solved by technology

[0010] It can be seen from the previous reaction formula that 3 moles of water will be produced for every mole of 2,5-FDCA produced, and the experiment shows that the content of water has a great influence on the reaction, and the increase of water content will greatly reduce the selectivity of the product 2,5-FDCA , thus affecting the yield

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