Patent GB-588545-A (GB)
Title: Improvements in or relating to the recovery of fumaric acid from aqueous fermentation products
IPC: C12P7/46
Filed: 1945-02-28
Abstract: Fumaric acid is recovered from aqueous fermentation products containing it by the following steps:-acidification with a mineral acid, extraction of the fumaric acid with an organic solvent, extraction of the resulting extract with an aqueous solution of an alkaline reacting compound of an alkali metal followed by acidification of the aqueous extract with a mineral acid and crystallizing the fumaric acid therefrom.  Additional clarification treatment prior to acidification is preferable, e.g., filtration in the presence of lime, calcium phosphate or a filter aid such as Kieselguhr.  Treatment with activated carbon after acidification and prior to filtration is also convenient. Suitable extraction solvents are the normal and secondary butyl alcohols, the amyl alcohols and methyl propyl ketone and the extraction is preferably carried out in counter current fashion in a column.  Sodium hydroxide or sodium carbonate solutions are conveniently used for the alkaline extraction and this may be conducted either i n a single or multi stage unit. The operations with the exception of crystallization are preferably conducted at about 50 DEG C. or higher, small amounts, e.g., about 100 parts per million of sodium hexametaphosphate, being added to minimise any deposition of calcium sulphate.  Any fumaric acid which crystallizes out in the initial acidification step is separated and only the mother liquors extracted.  Examples describe the process in the case of fumaric fermented wash obtained from the fermentation of Inverted Cuban Raw Sugar and Inverted High Test Cane Molasses with a suitable mould using chalk as neutralizing agent, sulphuric acid being used in the acidification steps.ALSO:Fumaric acid is recovered from aqueous fermentation products containing it by the following steps: acidification with a mineral acid, extraction of the fumaric acid with an organic solvent, extraction of the resulting extract with an aqueous solution of an alkaline-reacting compound of an alkali metal, followed by acidification of the aqueous extract with a mineral acid, and crystallizing the fumaric acid therefrom. Additional clarification treatment prior to acidification is preferable, e.g. filtration in the presence of lime, calcium phosphate or a filter aid such as kieselguhr.  Treatment with activated carbon after acidification and prior to filtration is also convenient. Suitable extraction solvents are the normal and secondary butyl alcohols, the amyl alcohols and methyl propyl ketone.  The solvent extraction is preferably carried out in counter-current fashion in an extraction column while the alkaline extraction step may be conducted either in a single or multi-stage unit, aqueous solutions of sodium hydroxide or sodium carbonate being conveniently used.  Sulphuric acid is preferably employed in the final acidification stage.  The operations with the exception of crystallization are preferably conducted at about 50 DEG  C. or higher, small amounts, e.g. about 100 parts per million of sodium hexametaphosphate, being added to minimise any deposition of calcium sulphate.  A small excess of acid, for example, 0.5 per cent by weight, is preferably used for the initial acidification step and any fumaric acid which crystallises out at this stage is separated and only the mother liquors extracted.  Examples describe the process in the case of fumaric fermented wash obtained from the fermentation of Inverted Cuban Raw Sugar and Inverted High Test Cane molasses with a suitable mould using chalk as neutralizing agent, sulphuric acid being used in the acidification steps.