Skip to main content
ARS Home » Research » Publications at this Location » Publication #238348

Title: Ethanol production from citrus processing waste: SSF of high-matter-containing substrates

item Widmer, Wilbur
item GROHMANN, KAREL - Retired ARS Employee

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2009
Publication Date: 4/14/2009
Citation: Zhou, W., Widmer, W., Grohmann, K. 2009. Ethanol production from citrus processing waste: SSF of high-matter-containing substrates. Florida State Horticultural Society Meeting. Paper No. HP4.

Interpretive Summary:

Technical Abstract: Steam pretreatment followed by simultaneous saccharification and fermentation (SSF) of citrus processing waste (CPW) is a promising technology for the alternative disposal of CPW. Instead of consuming a large amount of energy for drying CPW, this new technology uses an enzyme mixture to convert CPW into ethanol and other co-products. In order to make ethanol production economically viable, it is desirable to obtain a high ethanol concentration in a low viscous fermented mash using a substrate with high solid content and small enzyme loading requirement in the SSF. In this study, we investigated the effects of dry matter content and enzyme loading on SSF and the viscosity of fermented CPW. Two levels of substrates (10% and 20% dry matter) were compared at three different enzyme loadings. It was found that the ethanol yield (as percentage of the theoretical) obtained from 10%-dry-matter substrate was similar to that obtained from 20%-dry-matter substrate. At 20%-dry-matter content, as pectinase loading was reduced from 11 mg/100 g substrate to 1.4 mg/100 g substrate, ethanol yield and the viscosity of fermented CPW did not change significantly. These results could lead to significant savings in enzyme and distillation costs for ethanol production from CPW.