EXTRACTIVE ETHANOL-PRODUCTION IN A MEMBRANE CELL RECYCLE BIOREACTOR

Abstract

Ethanol production kinetics of free Saccharomyces cerevisiae cells was compared in a continuous reactor and a cell recycle membrane reactor, with and without solvent extraction. In the continuous culture the in-situ extraction using dibutyl phthalate increased glucose conversion from 45% to 91%, the cell concentration from 10.2 g l-1 to 23.6 g l-1 and the ethanol productivity from 8.2 g l-1 h-1 to 20 g l-1 h-1 when a 270 g l-1 glucose solution was fed to the reactor at a dilution rate of 0.16 h-1. In the membrane cell recycle culture with the solvent extraction the ethanol productivity increased to 45 g l-1 h-1 and 70% of the ethanol produced was extracted to the solvent stream. The mathematical modeling of the extractive bioconversion predicted ethanol concentration and productivity of the system reasonably well.