RECOVERY OF CARBOXYLIC ACID FROM THEIR MAGNESIUM SALTS BY PRECIPITATION USING HYDROCHLORIC ACID, USEFUL FOR FERMENTATION BROTH WORK-UP

摘要

The invention provides a method for preparing a carboxylic acid, which methodcomprises the steps of providingmagnesium carboxylate, wherein the carboxylic acid corresponding with thecarboxylate is selected from the group consisting of2,5-furandicarboxylic acid, fumaric acid, adipic acid, itaconic acid, citricacid, glutaric acid, maleic acid, malonic acid, oxalic acid andfatty acids having more than 10 carbon atoms; acidifying the magnesiumcarboxylate with hydrogen chloride (HC1), thereby obtain-ing a solution comprising carboxylic acid and magnesium chloride (MgCb);optionally a concentration step, wherein the solutioncomprising carboxylic acid and MgCb is concentrated; precipitating thecarboxylic acid from the solution comprising the carboxylicacid and MgCb, thereby obtaining a carboxylic acid precipitate and a MgCbsolution. The inventors found that the addition of HClto a magnesium salt of the carboxylic acid and subsequent precipitation of thecarboxylic acid from the solution leads to a veryefficient separation of the carboxylic acid from a magnesium carboxylatesolution.