Method for preparing betaine hydrochloride

Abstract

The invention discloses a method for preparing betaine hydrochloride. The method comprises the following steps of: performing a quaterisation reaction on trimethylamine and chloroactic acid under the action of sodium iodide serving as a nucleophilic substitution catalytic; adding calcium oxide or calcium hydroxide; heating for discharging trimethylamine completely; acidifying with sulfuric acid to obtain a calcium sulfate-betaine hydrochloride solution; and filtering a reaction liquid, concentrating and crystallizing to obtain the betaine hydrochloride. In the method, an efficient catalyst is adopted, so that the reaction is rapid and complete; meanwhile, expensive alkalis and hydrochloric acid are not required, and only cheap calcium oxide and sulfuric acid are required; and meanwhile, no side reaction is performed, the yield is greatly increased, and the yield of the betaine hydrochloride is over 99 percent counted by chloroacetic acid, so that the cost of the method is over 20 percent lower than that of the conventional process; and the preparation period is short, the reaction conditions are mild, a product is separated easily and sufficiently, three wastes are not generated, and raw materials and a solvent can be used circularly, so that the method has higher economic efficiency and environment friendliness.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, in particular to a preparation method of betaine hydrochloride. Background technique [0002] The chemical name of betaine hydrochloride is trimethylglycine hydrochloride, which is a quaternary ammonium alkaloid with the molecular formula C 5 h 11 NO 2 ·HCL, can be dissolved in water and alcohol, the aqueous solution becomes acidic, can withstand high temperature below 200 ℃, and has strong oxidation resistance. As a new livestock and poultry feed additive, betaine hydrochloride has a profound impact on the growth and carcass quality of livestock and poultry. [0003] The preparation methods of betaine hydrochloride include natural beet molasses extraction method and chemical synthesis method. The former has certain limitations in its application and promotion due to the limited source of raw materials; the traditional chemical synthesis method adopts the reaction of chloroacetic aci...

AI Technical Summary

Problems solved by technology

There are following defects in this method: 1, this reaction presses SN1 nucleophilic substitution, because CL atom leaves relatively slowly, so reaction time is long; The reaction generates a large number of by-products, which greatly affects the product yield and quality; 3. The generated salt is difficult to separate and remove from betaine

[0005] In recent years, the research on this, such as the strong cation exchange resin method and the solvent method, has many problems such as high cost, difficult post-treatment, and inability to treat high-salt wastewater, which greatly limits the development of betaine industrialization

Images