Method for producing lactic acid and method for producing polylactic acid
US11597694B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2020 |
| Grant date | Mar 7, 2023 |
| Priority date | — |
| Expiry date | Jul 23, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07B2200/07
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Lactic acid is obtained by a method including (A) a step of continuous fermentation wherein a fermentation culture medium of a microorganism having an ability of lactic acid fermentation is filtered through a porous membrane having an average pore size of not less than 0.01 μm and less than 1 μm with a transmembrane pressure difference within the range of 0.1 to 20 kPa, and the permeate is collected, while retaining the non-permeated liquid in or returning the non-permeated liquid to the culture, and adding a fermentation feedstock to the culture; (B) a step of filtering the permeate obtained in Step (A) through a nanofiltration membrane; and (C) a step of distilling the permeate obtained in Step (B) under a pressure of not less than 1 Pa and not more than atmospheric pressure, at 25° C. to 200° C. to recover lactic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.