We demonstrate the suitability of a commercial membrane for the aqueous nanofiltration of biobased carboxylic acids. The system is suitable for their in situ separation from fermentation mixtures by selective permeation of the acids at low pH while the typical substrate glucose shows a quantitative retention.

Abstract

Nanofiltration is an energy efficient separation technology with yet not fully explored potential for in situ product recovery from fermentation solutions. In this work, a commercially available cellulose acetate nanofiltration membrane was investigated to separate different carboxylic acids from glucose in an aqueous solution. The membrane showed a high stability and good separation performance at low pH. Dead-end and cross-flow experiments revealed the transferability to real fermentation mixtures and demonstrate the possibility of coupling fermentation with in situ product separation.