Long chain normal dibasic acid production method

Abstract

The invention discloses a method for preparing a normal long chain binary acid. The method comprises the following steps: C9-C18 alkane or fatty acid is served as substrate and converted to relative long chain binary acid by fermentation method or enzyme method; the reaction liquid is pretreated for removing the thallus and residual alkane or fatty acid, a binary acid clear liquid is obtained, acidification crystallization is carried out, the acidification crystallization liquid is filtered by pressing, and the binary acid crude product is obtained; the binary acid crude product is refined by using knifing vaporization and short path distillation device under the vacuum condition or by using organic solvent. The normal long chain binary acid prepared by the method has high thermal stability and can be used for preparing nylon, thermosol, and polyester materials.

Description

technical field [0001] The invention relates to a production method of a normal long-chain dibasic acid, in particular, the invention relates to a method for producing a high thermal stability normal long-chain dibasic acid by a biological method. Background technique [0002] Long-chain dibasic acid (DCA) is the basic monomer raw material for a series of special synthetic materials. Long-chain dibasic acid and its derived monomers can be used to produce special nylon, polycarbonate, powder coatings, spices, hot melt adhesives, special lubricants It is an important raw material for synthetic spices, engineering plastics, cold-resistant plasticizers, high-grade lubricants, polyamide hot-melt adhesives, and powder coatings. [0003] At present, DuPont produces dodecanedibasic acid by chemical synthesis method, which uses n-butene as raw material. This chemical synthesis process needs to go through seven steps of high temperature and high pressure chemical reactions. This metho...

AI Technical Summary

Problems solved by technology

[0003] At present, DuPont produces dodecanedibasic acid by chemical synthesis method, which uses n-butene as raw material. This chemical synthesis process needs to go through seven steps of high temperature and high pressure chemical reactions. This method has obvious disadvantages: organic monoacid as impurity Exists because it terminates polymerization, removing monoacids would increase production costs, which is a thorny issue; dibasic acids with longer carbon chains cannot be produced

Dodecane dibasic acid is a product produced by chemical method. A small number of manufacturers occupy a monopoly position in the world, and the price has remained high for a long time, which seriously affects the cost of downstream products. other long-chain dibasic acids, which limits the application of downstream products

[0006] At present, the patented technology for the production of long-chain dibasic acids at home and abroad is to use alkanes as substrates to produce dibasic acids by biological fermentation or to use fatty acids as substrates to synthesize dibasic acids by chemical methods. Domestic fermentation methods produce long-chain dibasic acids based on alkanes. substances, but the concept of substrate conversion rate is not proposed in the patent, and the conversion rate of substrate alkanes is crucial to the production cost of dibasic acids

Abroad, there are reports on the fermentation of dibasic acids with fatty acids as substrates, but they all stay at the scale of shake flasks, and the level is relatively low. 8 -C 14 Fatty acids as substrates, fermented to produce C 8 -C 10 dibasic acid, the acid production level is only 10g / L, and cannot produce C 11 -C 18 dibasic acid

Although there are many patents on the extraction and refining of dibasic acids at home and abroad, none of them can solve the problem of product quality, and the products obtained by the proposed process are difficult to apply to the fields of nylon and polyester.