Synthetic method for glycine betaine hydrochloride

Abstract

The invention relates to a synthetic method for glycine betaine hydrochloride. The synthetic method comprises the following steps: successively adding monochloro acetic acid, a catalyst and ethanol into a reaction bottle; then raising the temperature to 100-115 DEG C; dehydrating a molecular sieve in a reflux position; carrying out a reaction for 2-8 hours; washing a reaction liquid twice; distilling separated ethyl chloroacetate at a reduced pressure; adding ethyl monochloroacetate into the reaction bottle; adding a certain amount of water; introducing trimethylamine gas; keeping the temperature at 20-45 DEG C; carrying out a reaction for 2-6 hours; then adding hydrochloric acid to raise the temperature and hydrolyze to distill water and ethanol therein; and reducing the temperature by 10-15 DEG C and carrying out crystallization and centrifugalization to obtain the glycine betaine hydrochloride. By synthesizing ethyl monochloroacetate from monochloro acetic acid and ethanol, synthesizing ethyl glycine betaine hydrochloride from the obtained pure ethyl monochloroacetate and trimethylamine, raising the temperature to hydrolyze in the presence of hydrochloric acid to obtain ethanol,and cooling the concentrated liquor to separate out glycine betaine hydrochloride, the purity of the prepared glycine betaine hydrochlorid is over 99% and the yield reaches over 97%. Inorganic salt solid waste is avoided.

Description

technical field

[0001] The invention relates to the technical field of furfural bioprocessing and utilization, in particular to a method for synthesizing betaine hydrochloride. Background technique

[0002] Betaine hydrochloride is a general term for a class of organic compounds, also known as betaine hydrochloride, which is white to slightly yellow crystalline powder with sour taste and hygroscopicity, easily soluble in water and ethanol, insoluble in ether, Chloroform, reacts with alkali. Betaine hydrochloride is a high-efficiency, high-quality, economical nutritional additive widely used in livestock, poultry and aquaculture to induce food and promote growth.

[0003] The current betaine hydrochloride production process uses chloroacetic acid and sodium hydroxide solution 1:1.2 (molar ratio) for neutralization reaction at 20-40°C, and then controls the temperature at 15-40°C to introduce trimethylamine for quaternization to generate betaine , and then acidified with hyd...