Technology for adopting bipolar membrane electrodialysis for preparing beta-aminopropionic acid

Abstract

The invention discloses a method for using bipolar membrane electrodialysis for preparing beta-aminopropionic acid. The method comprises the steps of using 3-aminopropanenitrile and a sodium hydroxideaqueous solution or a potassium hydroxide aqueous solution as raw materials for reaction to obtain a sodium beta-aminopropionate solution, then making sodium beta-aminopropionate directly subjected to action of bipolar membrane electrodialysis equipment, forming sodium hydroxide by combining ionized sodium ions and hydroxyl, forming the beta-aminopropionic acid by combining aminopropionic acid radicals and hydrogen ions, and obtaining a high-purity product by conducting concentration and crystallization on the beta-aminopropionic acid. According to the production method, no hydrochloric acidor sulfuric acid is used for acidifying the sodium beta-aminopropionate, no wastewater is generated, no solvents need to be used in the crystallization process, solvent residues in the product are avoided, the purify can be over 99%, moreover, a generated sodium hydroxide solution can be recycled, thus an economic effect is good, moreover, the theoretical yield of the technology is 100%, and the actual yield can be over 90%.

Description

technical field [0001] The invention relates to the field of electrochemistry, in particular to a process for preparing β-alanine by bipolar membrane electrodialysis. Background technique [0002] β-alanine is a multi-purpose organic synthetic raw material, currently mainly used in the synthesis of calcium pantothenate, pantothenic acid, carnosine, guanidinopropionic acid, ethyl propionate hydrochloride, β-alanine nitrate, pamidronate Sodium, balsalazide, etc. are widely used in food, feed, medicine, etc., and are in great demand. At present, domestic manufacturers of β-alanine are mainly manufacturers of calcium pantothenate, including Brother Pharmaceutical, Yifan Pharmaceutical, Shandong Xinfa Pharmaceutical, Shandong Huachen Biology, and Hubei Xianlong. Its industrial production methods are mainly acrylonitrile ammonification hydrolysis method, acrylic acid ammonification method, biological enzyme catalysis (L-aspartic acid decarboxylase / nitrilase) method. [0003] Amo...

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Problems solved by technology

[0003] Among these methods, the acrylic acid route process is relatively simple, but there is a dynamic equilibrium in the reaction, low reaction yield, and equipment corrosion; although the reaction conditions of the enzymatic process are mild, the cost of raw materials is high, and fermentation produces a large amount of wastewater, which is not conducive to industrialization; The cost of the acrylonitrile route is the lowest, and the raw materials are easy to obtain. The current process is generally as follows: hydrolyze β-aminopropionitrile under liquid alkali conditions, then neutralize it with hydrochloric acid, then concentrate and filter to obtain about 45% of the crude product of β-alanine; After dissolving in water, filter, and then cool down and crystallize and filter the filtrate to obtain about 70% of aminopropionic acid. The filter cake is sodium chloride, and the sodium chloride is washed with water. After washing out the β-alanine, return to the previous concentration stage for concentration; 70 % of β-alanine is dissolved in hot water for decolorization, methanol is added for alcohol analysis, and the refined product of β-alanine is obtained by filtration, and the finished product is obtained after drying. The distillation raffinate is put back to the previous concentration stage for cyclic concentration; the disadvantages of this process are: 1. In the process of converting sodium aminopropionate into aminopropionic acid, there are often long procedures, long production cycles, and unstable product quality. Disadvantages; 2. It is necessary to use hydrochloric acid or sulfuric acid to acidify sodium allanate. This process will not only generate a large amount of waste water, but also increase the difficulty of the mother liquor crystallization process due to salt production, resulting in solvent residues and low yields in the product

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