Simultaneous saccharification, filtration and fermentation (SSFF) was developed for lignocellulosic ethanol
production. In SSFF, pretreated lignocellulosic material is enzymatically hydrolyzed in a reactor, while
the suspension is continuously pumped through a cross-flow membrane. The retentate goes back to the
hydrolysis vessel, while a clear sugar-rich filtrate continuously perfuses through the fermentation vessel
before it is pumped back to the hydrolysis vessel. The capacity and life span of the cross-flow filter module
was examined for 4 weeks using enzymatically hydrolyzed slurry, initially with 14.4% suspended solids,
without clogging or fouling. An ethanol yield of 85.0% of the theoretical yield was obtained in SSFF
and a flocculating strain of Saccharomyces cerevisiae was successfully reused for five cultivations of SSFF.