CN1166625C - The synthetic method of betaine hydrochloride - Google Patents

Abstract

The invention discloses a green synthesis method of betaine hydrochloride. Its synthesis steps are as follows: 1) chemical reaction: put calcium chloroacetate into the reaction bottle, add water, add trimethylamine aqueous solution in proportion, control the system temperature, and keep warm; 2) separation and purification: the reaction solution is acidified with sulfuric acid or phosphoric acid, filtered, The filter cake is dried to obtain by-product calcium sulfate or calcium phosphate; 3) concentrated crystallization: the filtrate is concentrated by evaporation, crystallized, and dried. The present invention has short technological process, mild operating conditions, low energy consumption, good separation and purification effect, and can produce betaine hydrochloride products with a purity of more than 98.5% and a yield of more than 96%, which effectively solves the problem of existing betaine salts. The salt synthesis method has problems such as complex separation process, high energy consumption, and environmental pollution.

Description

The synthetic method of betaine hydrochloride

Technical field

The invention relates to a green synthesis method of betaine hydrochloride.

Background technique

Betaine widely exists in animals and plants, and its basic function as a feed additive is as a methyl donor for animals, which can replace methionine and choline chloride, and can promote animal growth and improve feed conversion efficiency. Secondly, betaine is a new type of nutrient redistribution agent for livestock and poultry. Adding betaine in the diet can increase the carcass lean meat percentage, reduce the backfat thickness of fattening pigs, improve the quality and flavor of meat products, and increase the myoglobin, Intramuscular fat and inosinic acid content, which is of great significance for improving the color, aroma and taste of meat. Betaine has been widely used as a feed additive in the aquaculture industry. At present, the commercial betaine at home and abroad is mainly supplied in the form of betaine hydrochloride.

Most of the betaine as a feed additive is a natural substance extracted from sugar beet waste honey by ion exchange method or ion exclusion method; although the extraction method has raw materials that are cheap and easy to obtain, it is limited by seasons and regions, and separation The process is complicated, the energy consumption is high, and the environment is polluted; in recent years, the production technology of betaine or betaine hydrochloride has developed from extraction to chemical synthesis, and its products have been put into industrial production. The chemical synthesis method generally uses sodium chloroacetate and trimethylamine as raw materials, reacts in an aqueous solution under normal pressure to obtain equimolar betaine and sodium chloride, and then uses ion exchange, ion exclusion or recrystallization to separate betaine and chlorine. Sodium chloride, through decolorization, evaporation and concentration, crystallization, and filtration to obtain pure betaine, or add an appropriate amount of hydrochloric acid, crystallize and filter to obtain betaine hydrochloride; but since the separation and post-treatment process is basically the same as the extraction method, it is obviously also There are the same disadvantages as the extraction method, namely complex process, high energy consumption and environmental pollution.

Contents of Invention

The object of the present invention is to provide a kind of green synthetic method of betaine hydrochloride, concrete synthetic steps are as follows:

1) chemical reaction

At room temperature, put calcium chloroacetate into a reaction flask equipped with a stirring and reflux condenser, add water at a weight ratio of 3.5 to 4.5 times, and slowly add 30 % trimethylamine aqueous solution, the temperature of the control system does not exceed 40°C, and after the feeding is completed, keep it warm for 1.5 to 3 hours.

2) separation and purification

Acidify the reaction solution in step (1) with sulfuric acid or phosphoric acid to make pH = 1 to 1.5, filter until no white precipitate is present, and dry the filter cake to obtain by-product calcium sulfate or calcium phosphate.

3) concentrated crystallization

Evaporate and concentrate the filtrate in step (2) until a large amount of solid crystals precipitate out, and dry under normal pressure or vacuum at 100-105°C to obtain betaine hydrochloride.

The above-mentioned calcium chloroacetate is prepared by the neutralization reaction of chloroacetic acid and calcium hydroxide or calcium carbonate.

The green synthesis method of betaine hydrochloride of the present invention, owing to adopted calcium chloroacetate as raw material, can reduce reaction temperature, shorten reaction time, make reaction easy to control; And can utilize precipitation reaction, realize easily by betaine and chlorine The separation of the reaction solution composed of calcium chloride can produce a purity of more than 98.5%, and a betaine hydrochloride product with a yield (in terms of calcium chloroacetate) greater than 96%, and the obtained by-product calcium sulfate or calcium phosphate can also be used as a feed additive or Comprehensive utilization. Therefore, it has the characteristics of mild operating conditions, short process flow, low energy consumption and no environmental pollution.

Detailed ways

The present invention is further illustrated in conjunction with the following examples.

Example 1

At room temperature, put calcium chloroacetate into a reaction flask equipped with a stirring and reflux condenser, add water at a weight ratio of 3.5 times, and slowly add 30% trimethylamine dropwise at a molar ratio of calcium chloroacetate to trimethylamine of 1:2.2 Aqueous solution, the temperature of the control system does not exceed 40°C. After the feeding is completed, keep it warm at 40°C for 1.5 hours; the reaction solution is acidified with sulfuric acid to make the pH = 1, until there is no white precipitate, filter, and the filter cake is dried to obtain the by-product calcium sulfate ; The filtrate was evaporated and concentrated until a large number of solid crystals were precipitated, and dried under normal pressure at 100 ° C to obtain betaine hydrochloride.

Example 2

At room temperature, put chloroacetic acid into a reaction flask equipped with stirring and reflux condenser, add 4.5 times the weight ratio of water to dissolve, put into calcium hydroxide for neutralization according to the molar ratio of chloroacetic acid and calcium hydroxide at 2:1.05, and then press The molar ratio of chloroacetic acid and trimethylamine is 1: 2.0 and slowly add 30% trimethylamine aqueous solution dropwise, and the temperature of the control system does not exceed 40°C. After the addition is completed, it is kept at 40°C for 3 hours; the reaction solution is acidified with sulfuric acid to make pH = 1.5, until there is no white precipitate, filter, and dry the filter cake to obtain calcium sulfate as a by-product; the filtrate is evaporated and concentrated until a large amount of solid crystals are precipitated, and then vacuum-dried to obtain betaine hydrochloride.

Example 3

At room temperature, put chloroacetic acid into a reaction flask equipped with stirring and reflux condenser, add water with a weight ratio of 4.5 times, and put in calcium carbonate for neutralization according to the molar ratio of chloroacetic acid and calcium carbonate at 2: 1.1, then press chloroacetic acid and calcium carbonate The molar ratio of trimethylamine is 1:2.1, slowly add 30% trimethylamine aqueous solution dropwise, and the temperature of the control system does not exceed 40°C. After the addition is completed, keep the temperature at 40°C for 2 hours; the reaction solution is acidified with sulfuric acid to make pH=1.0 , until there is no white precipitate, filter, and dry the filter cake to obtain the by-product calcium sulfate; the filtrate is evaporated and concentrated until a large amount of solid crystals are precipitated, and dried under normal pressure at 105°C to obtain betaine hydrochloride.

Example 4

At room temperature, put chloroacetic acid into a reaction flask equipped with stirring and reflux condenser, add water with a weight ratio of 4.5 times, and put in calcium carbonate for neutralization according to the molar ratio of chloroacetic acid and calcium carbonate at 2: 1.1, then press chloroacetic acid and calcium carbonate The molar ratio of trimethylamine is 1:2.1, slowly add 30% trimethylamine aqueous solution dropwise, and the temperature of the control system does not exceed 40°C. After the addition is completed, keep the temperature at 40°C for 2 hours; the reaction solution is acidified with phosphoric acid to make pH=1.2 , until there is no white precipitate, filter, and the filter cake is dried to obtain the by-product calcium phosphate; the filtrate is evaporated and concentrated until a large amount of solid crystals are precipitated, and dried under normal pressure at 100°C to obtain betaine hydrochloride.

Example 5

At room temperature, put calcium chloroacetate into a reaction flask equipped with a stirring and reflux condenser, add water at a weight ratio of 4.5 times, and slowly add 30% trimethylamine dropwise at a molar ratio of calcium chloroacetate to trimethylamine of 1:2.0 Aqueous solution, the temperature of the control system does not exceed 40°C. After the feeding is completed, it is kept at 40°C for 3 hours; the reaction solution is acidified with phosphoric acid to make the pH = 1.5, until there is no white precipitate, filter, and the filter cake is dried to obtain the by-product calcium phosphate ; The filtrate was evaporated and concentrated until a large number of solid crystals were precipitated, and dried in vacuum to obtain betaine hydrochloride.

Example 6

At room temperature, put chloroacetic acid into a reaction flask equipped with stirring and reflux condenser, add 4 times the weight ratio of water to dissolve, put into calcium hydroxide for neutralization according to the molar ratio of chloroacetic acid and calcium hydroxide as 2: 1.05, and then press The molar ratio of chloroacetic acid and trimethylamine is 1: 2.0 and slowly add 30% trimethylamine aqueous solution dropwise, and the temperature of the control system does not exceed 40°C. After the addition is completed, it is incubated at 40°C for 1.5 hours; the reaction solution is acidified with phosphoric acid to make pH = 1.0, until there is no white precipitate, filter and dry the filter cake to obtain the by-product calcium phosphate; the filtrate is evaporated and concentrated until a large amount of solid crystals are precipitated, and dried under normal pressure at 100°C to obtain betaine hydrochloride.

Claims (2)

1. a synthetic method of betaine hydrochloride is characterized in that its synthetic steps are as follows: 1) chemical reaction At room temperature, put calcium chloroacetate into a reaction flask equipped with a stirring and reflux condenser, add water at a weight ratio of 3.5 to 4.5 times, and slowly add 30 % trimethylamine aqueous solution, the temperature of the control system does not exceed 40 ° C, after the feeding is completed, keep it warm for 1.5 to 3 hours, 2) separation and purification The reaction solution of step (1) is acidified with sulfuric acid or phosphoric acid to make the pH 1.0 to 1.5, until no white precipitate is present, filter, and the filter cake is dried to obtain by-product calcium sulfate or calcium phosphate. 3) concentrated crystallization Evaporate and concentrate the filtrate in step (2) until a large amount of solid crystals precipitate out, and dry under normal pressure or vacuum at 100-105°C to obtain betaine hydrochloride. 2. according to the synthetic method of a kind of betaine hydrochloride described in claim 1, it is characterized in that said calcium chloroacetate adopts chloroacetic acid and calcium hydroxide or calcium carbonate neutralization reaction to make.