Process of separating citric acid and/or isocitric acid or their salts from aqueous solutions
US4075093A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1975 |
| Grant date | Feb 21, 1978 |
| Priority date | — |
| Expiry date | Oct 23, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2325/16
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The process of separating citric acid and/or isocitric acid and their salts from aqueous solutions containing said acids or their salts, and especially from fermentation solutions, consists in contacting said solutions under pressure with a permselective membrane. The material composing said membrane has introduced thereinto acid or basic groups so as to yield membranes of predetermined swelling power. Preferred membranes are those consisting of polyimide or polyamide polycondensation products which are modified by acid or basic groups, of polysulfones modified by acid groups, or of vinyl polymers modified by acid or basic groups. Adjustment of the starting solutions to a pH lower than 3.0 is advantageously effected by means of polyvinylsulfonic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.