Continuous process for preparing lactic acid
US6509179B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Oct 12, 2000 |
| Grant date | Jan 21, 2003 |
| Priority date | — |
| Expiry date | Oct 12, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a continuous process for preparing lactic acid, comprising:(a) acidifying an aqueous feed, which has been obtained by fermentation and mainly contains lactate, with a stream containing inorganic acid to a pH of from 1 to 4 to form an aqueous stream which mainly consists of lactic acid and a salt,(b) removing the salt from the aqueous stream which mainly contains lactic acid and salt to form a first aqueous stream which mainly contains lactic acid,(c) passing the first aqueous stream which mainly contains lactic acid over a column containing activated carbon to form a second aqueous stream which mainly contains lactic acid,(d) subjecting the second aqueous stream which mainly contains lactic acid to a first extraction step, wherein the second aqueous stream which mainly contains lactic acid is brought into contact with a substantially water-insoluble stream which contains an extractant, to form an organic phase which mainly contains lactic acid and extractant and a first water phase which mainly contains impurities,(e) subjecting the organic phase which mainly contains lactic acid and extractant to a second extraction step, wherein the organic phase which ma…
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