Separation and extraction of lactic acid from fermentation broth using solvent extraction method

Lactic acid is the raw material for synthesizing polylactic acid. The composition of lactic acid fermentation broth is very complex, so it is difficult to separate and extract lactic acid from the fermentation broth. Currently, there are many methods used on the market, and different methods have different effects. Let's take a look together.

Method for separating and extracting lactic acid from fermentation broth:

At present, the main methods for separating and extracting lactic acid from fermentation broth include crystallization separation technology, esterification hydrolysis method

Extraction method, molecular distillation method, membrane separation method, adsorption method, chromatographic separation technology, etc. Each method has its own advantages and disadvantages, for example, the crystallization separation method can effectively improve the optical purity of the product, but the yield is low. The esterification method can produce high-purity lactic acid and separate it from other organic acids, but the yield of purified lactic acid is relatively low. Molecular distillation technology has low one-way yield for extracting lactic acid products, high equipment investment, and can only be used for deep processing of lactic acid products, and cannot directly obtain lactic acid from fermentation broth. Further purification of the product obtained by adsorption method is difficult. When the fermentation broth contains organic acids with similar polarity to lactic acid, the separation effect of chromatographic separation technology is also poor, and the solvent consumption is high.

Solvent extraction method for extracting lactic acid:

Solvent extraction is currently one of the main methods for extracting lactic acid. It utilizes the principle of similar solubility between the extractant and the extracted component to extract the component from the raw material liquid, and then undergoes a reverse extraction process to obtain the final product. The extractants used for lactic acid extraction include n-butanol, trialkyl phosphorus oxide, butyl phosphate, and amine substances. The solvent reaction extraction technology is simple and feasible, with obvious cost advantages and high economic feasibility, and has good application prospects. However, there are also feedback that there are problems such as low inclusion rate and incomplete extraction during use, so professional technology is needed to optimize the process and equipment in order to achieve the desired extraction effect.

The suitable equipment for extracting lactic acid using solvent extraction method is a centrifugal extractor. This is a new type of liquid-liquid extraction equipment that separates two incompatible liquids under the action of high-speed centrifugal force. It has various advantages such as high extraction efficiency, low usage cost, stable operation, and convenient operation. Currently, it is widely used on the market.