Method for preparing triethyl citrate through using nanometer intercalated hydrotalcite catalyst

Abstract

The invention discloses a method for preparing triethyl citrate through using a nanometer intercalated hydrotalcite catalyst. The method comprises the following steps: 1, charging: adding the nanometer intercalated hydrotalcite catalyst, citric acid and excess ethanol to a container, and stirring the added materials until uniformity; 2, carrying out an esterification reaction: carrying out oil bath heating, continuously adding ethanol in the heating process until ethanol is excess, and carrying out condensation refluxing and evaporated ethanol collection, wherein the esterification reaction is carried out for 16-20h; and 3, purifying: filtering out the nanometer intercalated hydrotalcite catalyst after the esterification reaction ends, dealcoholizing, neutralizing the dealcoholized material, washing the neutralized material with water, decolorizing the washed material, and purifying the decolorized material to obtain the finished triethyl citrate. The method for preparing triethyl citrate by using the nanometer intercalated hydrotalcite catalyst allows the citric acid conversion rate to be not lower than 99%, the product prepared in the invention is highly pure, the whole catalysis reaction is easy to operate, the temperature is easy to control, and the catalyst can be repeatedly used after being filtered.

Description

technical field [0001] The invention relates to a chemical catalysis method, in particular to a method for preparing triethyl citrate by using a hydrotalcite catalyst. Background technique [0002] Triethyl citrate (TEC) is a new type of non-toxic plasticizer, which can be used as deodorant, food additive, etc. Soluble in most organic solvents, and many cellulose and resins such as cellulose acetate, ethyl cellulose, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetate, chlorinated rubber, etc. Have good compatibility. As a plasticizer, due to the toxicity of DOP, the production of citric acid ester has been greatly developed abroad recently, such as Pricey Company and Morflex Company in the United States. Among them, triethyl citrate has been approved by the US Food Administration (FDA) as a non-toxic plasticizer, and is widely used in food packaging, medical appliances, children's toys, personal hygiene products, cigarette fi...

AI Technical Summary

Problems solved by technology

For a long time, the synthesis of triethyl citrate is to use concentrated sulfuric acid as a catalyst. Due to the strong oxidizing property of concentrated sulfuric acid, it is easy to carbonize and oxidize organic matter, and the side reactions increase. The strong corrosiveness has a great impact on the service life of the equipment, and the discharge of a large amount of waste acid also pollutes the environment. Therefore, finding new environmentally friendly catalysts is the research focus of the industry

[0003] At present, some use aluminum chloride or strong solid acid to catalyze triethyl citrate, but these catalysts are not easy to remove impurities during use, and still cause side reactions