Method for preparing glutaric acid from dimethyl glutarate

Abstract

The invention discloses a method for preparing glutaric acid from dimethyl glutarate. The glutaric acid is prepared by taking a strongly acidic styrene type cation exchange resin as a catalyst and taking dimethyl glutarate and water as raw materials through a hydrolytic-catalytic reaction. Each liter of reaction solution contains 100 to 330g of resin, the volume ratio of the water to the dimethylglutarate is 6:1-20:1, the heating temperature of a reaction system is between 90 and 140 DEG C, and the reaction time is between 1 and 8h. The hydrolytic-catalytic reaction system is also provided with a fractionating device used for fractionating methanol generated by the reaction. The method has the advantages that: other organic solvents are unnecessarily added, the preparation system is circular and closed, and a preparation process is environment-friendly; the catalyst is high in activity, low in consumption and high in catalytic efficiency, and the conversion ratio of the dimethyl glutarate is can reach over 85 percent; the catalyst can recycled by a simple filtering step, and keeps the stable catalytic performance; and the raw materials and the catalyst are all sold on the market,so that the method has low cost and broad application prospect.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing glutaric acid compound by catalytic hydrolysis of dimethyl glutarate solid acid cation exchange resin. Background technique [0002] Glutaric acid, also known as gum acid and 1,3-propanedicarboxylic acid, is a raw material for organic synthesis. Its dehydration product, glutaric anhydride, can be used as an initiator for synthetic resin, synthetic rubber and polymerization. It can be widely used in chemistry, construction, medicine, agriculture, etc., and the current market price has exceeded 72,000 yuan / ton. In the plastic industry, glutaric acid and its alkyl esters of glutaric acid are used as intermediates for plasticizers such as polyvinyl chloride, polyester, polyamide, etc. Composition. Glutaric acid not only has a killing effect on bacteria parasitic on animal body tissues, but also is a good killer against plant diseases and insect p...

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Problems solved by technology

[0004] Alkali hydrolysis process uses inorganic strong base KOH or CsOH as the reaction reagent, and the solvent system is H 2 O-THF, acidification after alkali hydrolysis to obtain glutaric acid, this method is highly corrosive, complicated process route, and low yield

[0005] In the research literature on the hydrolysis of dimethyl glutarate by cationic exchange resin method, dimethyl glutarate is only a special case of dimethyl dibasic acid. With strong acidic cation exchange resin as catalyst, dimethyl terephthalate - The hydrolysis behavior of the water-organic solvent mixed system has been studied on the influence of kinetics and catalyst structure on the reaction. On the one hand, a complete process has not been formed, and on the other hand, toxic organic solvents are used in the process, which has a great impact on the environment.

[0006] And about utilizing the glutaric acid dimethyl ester cationic exchange resin catalytic hydrolysis process without organic solvent auxiliary reaction, there is no relevant open technology at present

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