The present disclosure provides a method and a system for extracting long chain dicarboxylic acid, the method comprising: (1) subjecting a long chain dicarboxylic acid fermentation broth to a primary membrane filtration treatment to give a first filtrate; subjecting the first filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a first solid; (2) mixing the first solid, a base and water to form a solution; subjecting the solution to a secondary membrane filtration treatment to give a second filtrate; subjecting the second filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a second solid; and (3) mixing the second solid and water to form a mixture; subjecting the mixture to a thermostatic treatment at 105-150° C., followed by cooling for crystallization and solid-liquid separation treatment. By the method, the resulted long chain dicarboxylic acid product has a high purity and no residual organic solvent.

The present disclosure provides a method and a system for extracting long chain dicarboxylic acid, the method comprising: (1) subjecting a long chain dicarboxylic acid fermentation broth to a primary membrane filtration treatment to give a first filtrate; subjecting the first filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a first solid; (2) mixing the first solid, a base and water to form a solution; subjecting the solution to a secondary membrane filtration treatment to give a second filtrate; subjecting the second filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a second solid; and (3) mixing the second solid and water to form a mixture; subjecting the mixture to a thermostatic treatment at 105-150° C., followed by cooling for crystallization and solid-liquid separation treatment. By the method, the resulted long chain dicarboxylic acid product has a high purity and no residual organic solvent.

The present disclosure provides a method and a system for refining long chain dicarboxylic acid, said method comprising the following steps: (1) subjecting a long chain dicarboxylic acid fermentation broth or a treated liquid therefrom to a membrane filtration, an acidification/crystallization, a solid-liquid separation and drying to give a long chain dicarboxylic acid crude product; (2) subjecting the long chain dicarboxylic acid crude product to a vacuum distillation to give the long chain dicarboxylic acid product; wherein the pressure in the vacuum distillation is ≤100 Pa. By using the refining method according to the present disclosure, the procedure is simplified, and the purity of the obtained product is high, and the disadvantages such as poor quality of the product obtained by crystallization from a solvent and environment pollution caused by a solvent can be overcome.

The present disclosure provides a method and a system for refining long chain dicarboxylic acid, said method comprising the following steps: (1) subjecting a long chain dicarboxylic acid fermentation broth or a treated liquid therefrom to a membrane filtration, an acidification/crystallization, a solid-liquid separation and drying to give a long chain dicarboxylic acid crude product; (2) subjecting the long chain dicarboxylic acid crude product to a vacuum distillation to give the long chain dicarboxylic acid product; wherein the pressure in the vacuum distillation is ≤100 Pa. By using the refining method according to the present disclosure, the procedure is simplified, and the purity of the obtained product is high, and the disadvantages such as poor quality of the product obtained by crystallization from a solvent and environment pollution caused by a solvent can be overcome.

The present disclosure provides method for isolating a long chain dicarboxylic acid such as a substantially pure or pure long chain dicarboxylic acid from a fermentation broth containing microbial cells.

The present disclosure provides method for isolating a long chain dicarboxylic acid such as a substantially pure or pure long chain dicarboxylic acid from a fermentation broth containing microbial cells.

The present disclosure provides method for isolating a long chain dicarboxylic acid such as a substantially pure or pure long chain dicarboxylic acid from a fermentation broth containing microbial cells.

There is disclosed a process for the separation of long chain amino acid and long chain dibasic acid, comprising: (1) adding an ammonium salt to the mixture of alkali salts of long chain amino acid and long chain dibasic acid; (2) heating to remove ammonia; and (3) separating long chain amino acid by solid-liquid separation; and (4) acidifying the salt of long chain dibasic acid with an acid to separate long chain dibasic acid.

There is disclosed a process for the separation of long chain amino acid and long chain dibasic acid, comprising: (1) adding an ammonium salt to the mixture of alkali salts of long chain amino acid and long chain dibasic acid; (2) heating to remove ammonia; and (3) separating long chain amino acid by solid-liquid separation; and (4) acidifying the salt of long chain dibasic acid with an acid to separate long chain dibasic acid.

There is disclosed a process for the production of dodecanedioic acid and 11-aminoundecanoic acid, comprising: (1) reacting castor oil with a primary or secondary amine to form a amide; (2) isomerizing the amide in the presence of a catalyst to form ketoamide; (3) reacting the ketoamide with hydroxylamine to form the oximeamide; (4) subjecting the oximeamide to Beckmann rearrangement to yield a mixture of two diamides; and (5) hydrolyzing the mixed diamides to produce dodecanedioic acid, 11-aminoundecanoic acid, hexylamine and heptanoic acid.