The effect of dry matter content on the simultaneous saccharification and fermentation of citrus processing waste

Abstract

Citrus processing waste (CPW) is an attractive feedstock for making fuel ethanol. In order for ethanol production from citrus waste to be economically viable, it is desirable to obtain a high ethanol yield and concentration with a small amount of enzymes. In this study, we investigated the effects of dry matter content and pectinase loading on the simultaneous saccharification and fermentation of pretreated CPW. Two levels of substrates (10% and 20% dry matter) were compared at three different pectinase loadings. It was found that the ethanol yield (as percentage of the theoretical) obtained from 20% dry-matter substrate was similar to that obtained from 10% dry-matter substrate. These results could lead to significant savings in enzyme and distillation costs for ethanol production from CPW.