阅读说明：本技术 一种氨法甜菜碱的制备方法 (Preparation method of ammonia-process betaine ) 是由 刘长飞 李志伟 王云鹤 于 2019-03-03 设计创作，主要内容包括：一种环保氨法水相制备甜菜碱的方法,同时联产农用氯化铵副产品。氯乙酸铵水溶液与三甲胺进行季铵化反应,合成甜菜碱和氯化铵溶液,先经过减压蒸发、浓缩除去游离的三甲胺,再经过蒸发、降温结晶、分离出去大部分氯化铵。剩下的水溶液,通过电渗析,分离出去氯化铵,得到甜菜碱水溶液,再经过蒸发浓缩、降温结晶、离心、干燥后,得到高品质的甜菜碱产品。(An environment-friendly method for preparing betaine from water phase by ammonia process, and coproducing agricultural ammonium chloride byproduct. Performing quaternization reaction on ammonium chloroacetate aqueous solution and trimethylamine to synthesize betaine and ammonium chloride solution, removing free trimethylamine through reduced pressure evaporation and concentration, and removing most of ammonium chloride through evaporation, cooling crystallization and separation. And (3) performing electrodialysis on the rest aqueous solution, separating out ammonium chloride to obtain a betaine aqueous solution, and performing evaporation concentration, cooling crystallization, centrifugation and drying to obtain a high-quality betaine product.)

1. An environment-friendly method for preparing betaine from water phase by ammonia process, which produces betaine and coproduces agricultural ammonium chloride byproduct, is characterized by comprising the following steps:

1) introducing ammonia or adding ammonium bicarbonate and ammonium carbonate into chloroacetic acid in the aqueous solution to synthesize an ammonium chloroacetate aqueous solution;

2) introducing ammonia or adding ammonium bicarbonate and ammonium carbonate into chloroacetic acid in an aqueous solution to synthesize ammonium chloroacetate, cooling, filtering to obtain ammonium chloroacetate solid, and recycling the filtrate to prepare ammonium chloroacetate;

3) adding ammonium chloroacetate aqueous solution in proportion into a reactor (comprising a kettle type reactor, a tubular reactor and a microreactor) for synthesizing betaine, and adding gaseous trimethylamine or trimethylamine aqueous solution in proportion to perform quaternization;

4) transferring the betaine and ammonium chloride aqueous solution synthesized in the step 3) into a reduced pressure concentration kettle, evaporating residual trimethylamine in the aqueous solution through reduced pressure concentration, performing neutralization reaction through a secondary washing tower, and recovering the trimethylamine;

5) recovering the solution of the trimethylamine, transferring the solution into a multi-effect evaporator, evaporating and concentrating the solution to a certain proportion, cooling, crystallizing, centrifugally separating out ammonium chloride, and washing the ammonium chloride with water to obtain a byproduct of agricultural ammonium chloride;

6) separating out the remaining solution of ammonium chloride, supplementing a certain amount of ammonium chloride washing water solution, and separating the ammonium chloride in the solution by adopting an electrodialyzer membrane separation technology to obtain a betaine solution and an ammonium chloride solution;

7) carrying out reduced pressure distillation, cooling, crystallization, centrifugation, washing and drying on the betaine solution obtained by electrodialysis separation to obtain a high-quality betaine product;

8) concentrating the ammonium chloride solution obtained by electrodialysis membrane separation through a high-pressure reverse osmosis device, returning the concentrated solution to the step 1) to be used as a water solvent, and adding chloroacetic acid to prepare an ammonium chloroacetate aqueous solution;

9) after the betaine aqueous solution is subjected to multiple cyclic reactions, impurities are enriched, the color is darkened, the cyclic reaction is not carried out any more, the impurities are treated in a centralized manner, and urea is added after catalytic oxidation to process the byproduct ammonium chloride fertilizer raw material product.

2. The method of claim 1, wherein: the molar ratio of ammonium chloroacetate to trimethylamine in the step 3) is 1: 1-1.1, and the weight ratio of ammonium chloroacetate to the aqueous solution is 1: 1-10.

3. The method of claim 1, wherein: the micro-reactor in the step 3) selects the diameter of the microporous membrane to be 1-10 microns, the channel size of the flow-through phase is 1-20 mm, the reaction time is 0.1-30 minutes, and the reaction temperature is 30-70 ℃.

4. The method of claim 1, wherein: and 4) evaporating residual trimethylamine in the solution by vacuum concentration in the step 4).

5. The method of claim 1, wherein: and 5) evaporating, concentrating, cooling, crystallizing and centrifuging to obtain a byproduct agricultural ammonium chloride.

6. The method of claim 1, wherein: and 6) separating the ammonium chloride in the solution by adopting an electrodialyzer membrane separation technology to obtain the betaine solution and the ammonium chloride solution.

7. The method of claim 1, wherein: and 7) distilling under reduced pressure, cooling, crystallizing, centrifuging, washing and drying the betaine solution obtained by the electrodialysis separation to obtain a betaine product.

8. The method of claim 1, wherein: concentrating the ammonium chloride solution obtained by the electrodialysis membrane separation in the step 8) through a high-pressure reverse osmosis device, wherein the concentrated solution is used for preparing an ammonium chloroacetate aqueous solution.

9. The method of claim 1, wherein: adding urea in the step 9), and processing into a byproduct ammonium chloride fertilizer raw material product.

Technical Field

The invention relates to a preparation method of betaine by an environment-friendly ammonia process, which is used for producing betaine and co-producing ammonium chloride and belongs to the technical field of chemical production.

Background

Betaine is also called betaine and trimethylglycine, and has good physical and chemical properties, good stability and oxidation resistance, high temperature resistance and acid and alkali resistance; the chemical structure of the compound is similar to that of amino acid and choline, has various biological functions, and is widely applied to the fields of feed additives, pharmaceutical industry, agriculture and forestry production, food additives, daily chemicals and the like. Has moisture keeping effect in cosmetic; the medicine has the effect of protecting liver, and the food has American FDA approval of betaine as a safe food additive and a dietary nutrition enhancer; the betaine can improve the utilization rate of energy in food, improve the effective absorption and utilization rate of amino acid, and protect liver; the feed additive is more widely applied to livestock, poultry and aquatic animals, can improve the utilization level of daily ration energy, stabilizes the quality of vitamins in the feed, has a protective effect on fat-soluble vitamins, can adjust osmotic pressure, is beneficial to maintaining the water and ion balance of cells, has obvious effects of maintaining the integrity of intestinal tracts and the health of the intestinal tracts when the animals generate stress, reduces the death of the aquatic animals in the processes of fishing and transporting, and reduces the cost of the feed. There are two main methods for production: separating from beet molasses, and synthesizing by chemical method.

Usually, chloroacetic acid, sodium hydroxide or sodium carbonate and trimethylamine are used as raw materials for neutralization reaction and quaternization reaction, ion resin or membrane separation is adopted, and then drying is carried out to obtain betaine or betaine hydrochloride is continuously prepared. In a word, the existing processes of betaine and betaine hydrochloride are not easy to control, byproducts are easy to generate, the investment is large, the product yield is low, a large amount of waste water is generated, and great environmental pressure is generated. In particular, the byproduct sodium chloride can be treated only as solid waste because of the organic matters.

Disclosure of Invention

The invention provides a method for preparing betaine from water phase by an environment-friendly ammonia process, which is used for co-producing agricultural ammonium chloride by-products while producing the betaine.

Firstly, chloroacetic acid reacts with ammonia (liquid ammonia or ammonia water) or ammonium carbonate and ammonium bicarbonate to synthesize ammonium chloroacetate aqueous solution or ammonium chloroacetate solid intermediate. And performing quaternization reaction on the ammonium chloroacetate aqueous solution and trimethylamine gas (or the trimethylamine aqueous solution) to synthesize betaine (trimethylglycine) and ammonium chloride. The aqueous solution containing betaine and ammonium chloride is subjected to reduced pressure evaporation and concentration to remove free trimethylamine, and then subjected to temperature reduction, crystallization and centrifugation to separate out most of ammonium chloride. And (3) performing electrodialysis on the rest aqueous solution, separating out ammonium chloride to obtain a betaine aqueous solution, and performing evaporation concentration, cooling crystallization, centrifugation and drying to obtain a high-quality betaine product.

The invention is realized by the following steps and methods:

step (1), preparing an intermediate ammonium chloroacetate:

chloroacetic acid (solid chloroacetic acid or liquid chloroacetic acid) is introduced into the aqueous solution for reaction (10-55 ℃) to synthesize the ammonium chloroacetate aqueous solution. Solid ammonium carbonate and ammonium bicarbonate can also be used to react with chloroacetic acid aqueous solution to synthesize ammonium chloroacetate, the reaction temperature is controlled at (10-40 ℃), and ammonium chloroacetate aqueous solution is obtained by filtration. The molar ratio of chloroacetic acid to ammonia is 1:1, the molar ratio of chloroacetic acid to ammonium carbonate is 1:0.5, and the molar ratio of chloroacetic acid to ammonium bicarbonate is 1: 1.

Chloroacetic acid can also react with ammonia, or ammonium carbonate and ammonium bicarbonate in aqueous solution (10-55 deg.C) to obtain ammonium chloroacetate solid. And (3) adding chloroacetic acid and ammonia or adding ammonium carbonate and ammonium bicarbonate into the filtrate to perform a circular reaction to prepare ammonium chloroacetate.

And (2) preparing betaine and ammonium chloride in an aqueous solution by taking ammonium chloroacetate and trimethylamine as raw materials:

in a reactor (including a kettle reactor, a tubular reactor and a microreactor) for synthesizing betaine, adding ammonium chloroacetate aqueous solution in proportion, or adding in batches or adding dropwise. Gaseous trimethylamine or trimethylamine water solution is added according to the proportion to carry out quaternization reaction. The reaction temperature is 30-70 ℃. The mol ratio of ammonium chloroacetate to trimethylamine is 1: 1-1.1, and the weight ratio of ammonium chloroacetate to aqueous solution is 1: 1-10.

The micro-reactor selects the diameter of the microporous membrane to be 1-10 microns, the channel size of the flow-through phase is 1-20 mm, the reaction time is 0.1-30 minutes, and the reaction temperature is 30-70 ℃. In the present invention, a membrane-dispersed microstructure reactor is preferably selected. The number of microchannel reactors is not particularly limited. When more than 2 microchannel reactors are used, each microchannel reactor is configured in series, and reaction raw materials sequentially enter each microchannel reactor. The structure of the microchannel reactor includes, but is not limited to, a rectangle, a trapezoid, a heart, a double trapezoid, and an irregular shape. In the reaction, the microchannel reactor may be used as different modules as needed, such as a mixing preheating module, a reaction module, a cooling module, and the like. These modules are only functionally distinct and the geometry may be identical.

And (3) transferring the betaine and ammonium chloride aqueous solution synthesized in the step (3) and the step (2) into a reduced pressure concentration kettle, evaporating residual trimethylamine in the aqueous solution through reduced pressure concentration, performing neutralization reaction through a secondary washing tower, and recovering the trimethylamine. Recovering the solution of trimethylamine, transferring the solution into a multi-effect evaporator, evaporating and concentrating the solution to a certain proportion, cooling, crystallizing, centrifugally separating out ammonium chloride, and washing the ammonium chloride with water to obtain a byproduct of agricultural ammonium chloride.

And (4) separating the remaining solution of ammonium chloride, supplementing a certain amount of ammonium chloride washing water solution, and separating the ammonium chloride in the solution by adopting an electrodialyzer membrane separation technology to obtain a betaine solution and an ammonium chloride solution. The electrodialysis membrane (ion exchange membrane) selected by the electrodialyzer comprises a homogeneous membrane, a heterogeneous membrane and a semi-homogeneous membrane.

And concentrating the ammonium chloride solution obtained by electrodialysis membrane separation through a high-pressure reverse osmosis device to obtain a concentrated solution and a permeated clear solution. And (3) returning the concentrated solution to the step (1) as an ammonium chloride solution, adding chloroacetic acid as a water solvent, and preparing an ammonium chloroacetate aqueous solution.

And (5) distilling the betaine solution obtained by electrodialysis under reduced pressure, cooling, crystallizing, centrifuging, washing and drying to obtain a high-quality betaine product.

And adding the betaine aqueous solution obtained by centrifugal separation into a betaine synthesis reactor for circular reaction.

After the betaine aqueous solution is subjected to multiple cyclic reactions, impurities are enriched, the color is darkened, the cyclic reaction is not carried out any more, the impurities are treated in a centralized manner, and the impurities are processed into a byproduct ammonium chloride fertilizer raw material product after catalytic oxidation.

The catalytic oxidation process of the betaine aqueous solution in the steps comprises the following steps: fenton oxidation (Fenton), photocatalytic oxidation, ozone catalytic oxidation, electrochemical oxidation, ultrasonic oxidation, supercritical water oxidation, wet catalytic oxidation and the like.

When the betaine aqueous solution wastewater is treated, urea needs to be added, the nitrogen content of an ammonium chloride product is increased, and the product can reach the standard specified by the national standard of ammonium chloride (GB/T2946-2008 ammonium chloride).

The specific embodiment is as follows:

the following examples are provided to further illustrate the essence of the present invention, but are not intended to limit the present invention.