Method for extracting and refining long-chain dicarboxylic acid crude product

Abstract

The invention relates to a method for extracting and refining a long-chain dicarboxylic acid crude product. The method comprises the following steps that: the filtrate and an extracting agent are mixed and heated, and an acid is added to carry out acidifying; a liquid-liquid separation treatment is performed after the extracting agent and the filtrate are subjected to complete mixing and standing under a certain pH value and a certain temperature; the extraction phase is cooled and crystallized; the solvent is removed, and a drying treatment is performed to obtain the purified product. According to the present invention, the adsorbent is not used, such that the process for separation of the adsorbent and the fermentation liquid is saved so as to substantially reduce the purification process; the method has characteristics of simple purification process, high purification yield, and easy control of the purification process.

Description

technical field [0001] The invention relates to a method for producing a long-chain dibasic acid product by a refined biological fermentation method in the field of petrochemical industry. The long-chain dibasic acid product produced by the biological fermentation method is purified by an extraction process. Background technique [0002] Long-chain dodecanedibasic acid is a fine chemical product with important and extensive industrial uses. It is mainly used in the synthesis of advanced engineering plastics nylon, nylon, high-grade nylon hot-melt adhesives for clothing, and advanced coatings. Dodecanedioic acid does not exist alone in nature, and it is difficult to synthesize it in the chemical industry. The United States, Germany, Russia, Japan and other countries have conducted long-term research on the chemical synthesis of dodecanedibasic acid, but so far, the chemical synthesis route is to use butadiene as a raw material for chemical synthesis, but it is both High-temp...

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Problems solved by technology

The disadvantage of the former is that the organic solvent is flammable, volatile, and toxic, and fireproof, explosion-proof, and poison-proof devices must be installed during post-treatment. Organic solvents are more expensive than water, volatile and easy to lose, and the cost is high. The advantage is that the crystal form is good and the crystal particles are large. , easy to separate; the disadvantage of the water treatment method is that the solubility of the dibasic acid in water is small, and the crystal shape and cr

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