"Membrane-based process for the recovery of lactic acid and glycerol from a ""corn thin stillage"" stream"
US5250182A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Jul 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E50/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
"Thin stillage", discharged from a centrifuge in which relatively large >10 .mu.m insoluble solids in an ethanol stillbottoms stream are separated from "whole stillage", is separated in a step-wise membrane separation process to recover lactic acid and glycerol, together. In each step, the permeate recovery is at least 50%. In a first step, an ultrafiltration (UF) membrane means produces a UF permeate stream in which not only essentially all the insoluble portion of said thin stillage >0.0.05 .mu.m is removed as UF concentrate, but also at least 50% of solubles having a molecular weight >2.times.10.sup.5 Daltons, including dissolved proteins in said thin stillage. In a second step to which the UF permeate is fed, a nanofiltration (NF) membrane produces a NF permeate with a rejection of less than 30% of both the lactic acid and the glycerol, preferably less than 25%. Essentially all molecules larger than lactic acid or glycerol are removed in the NF concentrate. In a third step, to which the NF permeate is fed, a reverse osmosis (RO) membrane means produces demineralized RO water which contains essentially no lactic acid and glycerol, because these are rejected in the RO concentrate…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.