Method for preparing food-grade rosin xylose ester through catalytic esterification- separation coupling

Abstract

The invention discloses a method for preparing food-grade rosin xylose ester through catalytic esterification-separation coupling. The method comprises the operation steps of (1) mixing xylose or xylitol, with rosin or hydrogenated rosin and a green solvent to obtain a mixture, and enabling the mixture to dissolve; (2) inflating CO2, and performing an esterification reaction; (3) continuously taking out a gas phase, and performing condensing and separation; (4) after the esterification reaction is performed for 2.0-16.0h, taking out reaction products from an esterification reaction reactor; and (5) performing constant-pressure distillation and underpressure distillation on the reaction products, and removing the green solvent to obtain the food-grade rosin xylose ester. The rosin or the hydrogenated rosin, and the xylose or the xylitol are used as the raw materials for preparing the food-grade rosin xylose ester, because the xylose or the xylitol is a natural healthy sweetening agent,and when the food-grade rosin xylose ester is used as a food additive, the sweetening agent does not need to be added additionally. The product produced by the method is safe and reliable, the green solvent is recycled, and the method is a green method and cleaning production process for preparing the food-grade rosin xylose ester from the rosin or the hydrogenated rosin through catalyzing.

Description

technical field [0001] The invention relates to the technical field of rosin deep processing, in particular to a method for preparing food-grade rosin xylose ester through catalytic esterification-separation coupling. Background technique [0002] Rosin ester is the most important species in rosin deep processing, accounting for more than 60% of rosin deep processing products. Because rosin resin acid has a three-ring phenanthrene skeleton structure, the steric hindrance of the carboxyl group is large, resulting in high activation energy of the esterification reaction, and the viscosity of the rosin reaction system is high, resulting in difficulty in interphase transfer between reactants. The esterification reaction of rosin resin acid can only be carried out under the conditions of acidic metal oxide catalyst and high temperature. However, under high temperature conditions, the rosin resin acid is prone to decarboxylation side reactions, resulting in a reduction in the est...

AI Technical Summary

Problems solved by technology

In the current technology, in the technology of preparing rosin esters after deep processing of rosin with catalysts, most of the catalysts use metal catalysts to esterify rosin to obtain rosin esters, but the use of metal catalysts for catalysis will cause metal ions to pollute rosin esters. If rosin ester contaminated by metal ions is used for food production, it will have adverse effects on the human body after use

Moreover, the preparation of rosin esters in the present technology is due to the use of metal catalysts, and sometimes even noble metal catalysts are used for catalytic reaction production, resulting in problems such as higher production costs, making the profit not high in the process of producing rosin esters

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