Extraction method of L-isoleucine

Abstract

The invention discloses an extraction method of L-isoleucine; the technique process of the invention includes the following steps: obtaining zymotic fluid containing the L-isoleucine by zymotechnics; carrying out filtration on the zymotic fluid after adding a neutral flocculating agent to remove thalli; adding active carbon into filtrate to carry out decoloring; the size of the liquid is condensed to 9 to 11 percent of the original size by heating and vacuum condensing; the condensed liquid is crystallized after being cooled to 24.5 to 25.5 DEG C; then the crude product is obtained by centrifugalizing; the crude product is dissolved into liquor of 3.5 percent and heated up to between 58 to 62 DEG C, then is decolored, filtered, condensed, crystallized and separated to obtain the secondary crude product; the operations are carried out again on the secondary crude product; only a hyperfiltration process is added when filtering and finally the wet finished product is obtained after crystallization. The extraction method has the advantages of greatly reducing the drain amount of waste water as the working procedure of ion exchange is replaced by only adopting the method of condensing crystallization; furthermore, the extraction absorption rate is also remarkably improved.

Description

technical field [0001] The invention relates to an extraction process of L-isoleucine, in particular to an improvement of the extraction process of L-isoleucine. Background technique [0002] At present, L-isoleucine is mostly produced by fermentation. For the extraction of L-isoleucine in the fermentation broth, the bacteria are removed by filtration at home and abroad. The pH of the filtrate is adjusted to 2.5-3.0, and it is adsorbed with 732 cation exchange resin L-isoleucine, then elute L-isoleucine with dilute ammonia water, decolorize the eluent with activated carbon, then concentrate and crystallize to obtain the crude product; dissolve the crude product, decolorize with activated carbon, and recrystallize to obtain the finished product L-isoleucine acid. Due to the ion exchange extraction method, a large amount of waste water is generated during the production process, and the amount of water generated reaches about 800 tons for every ton of finished product produce...

AI Technical Summary

Problems solved by technology

In addition, during the ion exchange adsorption process, the L-isoleucine in the adsorption waste liquid is not easy to control, resulting in a low product yield. At the same time, the extraction process consumes a large amount of sulfuric acid and ammonia water.

Higher extraction costs

In addition, due to the high content of impurity amino acids in the fermentation broth, it is not easy to be removed during the ion exchange process, resulting in a large amount of impurity amino acids in the product, which affects the quality of the final product

Therefore, the L-isoleucine extraction process currently adopted at home and abroad has the problems of large amount of sewage, low extraction yield, generally around 55%-60%, high cost, and poor product quality.