Method for extracting lactic acid from corn starch wastewater fermentation liquid by using anion exchange resin

Abstract

The invention discloses a method for extracting lactic acid from corn starch wastewater fermentation liquid by using an anion exchange resin and relates to a method for extracting the lactic acid from the corn starch wastewater fermentation liquid. The method solves the problem that the extraction ratio is low, the problem that extractant of an extraction method is toxic, the problem that the lactic acid cannot be separated from the extractant easily, and the problem that in a high molecular resin adsorption method, the selectivity of a high molecular resin and the static exchange capacity are low of the conventional, traditional and improved calcium lactate crystallization-acidolysis methods. The method comprises the following steps of: performing centrifugal filtration, active carbon decoloration and cation exchange resin column decalcification on the corn starch wastewater fermentation liquid; performing adsorption by using a 315-type anion exchange resin; and performing elution byusing deionized water to extract the lactic acid. The method has the advantages of fewer steps, simple operation, high selectivity and static exchange capacity, lactic acid extraction ratio of 78 to 80 percent, lactic acid purity of 85 to 86 percent and non-toxic and easily-separated eluant. The method is used for extracting the lactic acid in the corn starch wastewater fermentation liquid.

Description

Method for Extracting Lactic Acid in Fermented Liquid of Corn Starch Wastewater Using Anion Exchange Resin technical field The invention relates to a method for extracting lactic acid in cornstarch wastewater fermentation liquid. Background technique Lactic acid is an extremely important organic acid widely used in food, medicine and chemical industries. The industrial production of lactic acid mainly adopts microbial fermentation. The composition of lactic acid fermentation liquid is complex, in addition to lactic acid, it also includes bacteria, residual sugar, protein, pigment, colloid, organic acid, inorganic salt and other impurities. In general, they originate from raw materials, unconsumed nutrients, or intermediate by-products of fermentation, so it is more difficult to extract lactic acid from lactic acid fermentation broth. The lactic acid to be extracted in the present invention is obtained from cornstarch wastewater fermentation liquid, and the method is prep...

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Problems solved by technology

The present invention aims to solve the problem that the existing traditional and improved calcium lactate crystallization-acidolysis method has low extraction rate, the extraction agent used in the extraction method is toxic and it is difficult to efficiently separate lactic acid from the organic phase, and the high molecular weight in the polymer resin adsorption method. The problems of poor selectivity and low static exchange capacity of molecular resins provide a method for extracting lactic acid in cornstarch wastewater fermentation liquid with anion exchange resins