Engineering aspects of lignocellulosic biomass conversion to ethanol

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:140221

Philippidis, G P; Smith, T K ^[1]

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1. National Renewable Energy Lab., Golden, CO (United States)

The cellulosic fraction of biomass can be converted to ethanol, a promising alternative renewable fuel, using the simultaneous saccharification and fermentation (SSF) process. The SSF integrates the enzymatic hydrolysis of cellulose to glucose with the fermentation of glucose to ethanol. Ethanol productivity and yield depend on the characteristics of the biomass, the quality of the cellulase enzyme complex, and the behavior of the fermentative organism. The effects of key engineering factors on SSF performance were studied using real biomass substrate and realistic process conditions. The experimental results indicate that corn steep liquor can replace expensive lab media for the SSF. Saccharomyces cerevisiae D{sub 5}A outperforms other leading organisms in terms of both high ethanol productivity and minimal by-product formation. Using that organism, the SSF operational conditions (pH and temperature) were varied in order to optimize the synergism between the cellulase enzyme complex and the fermentative yeast. The SSF performance was optimal at 40{degrees}C and initial pH of 4.0--5.0. Higher temperatures resulted in a significant decrease in cell viability and productivity.

• Research Organization: National Renewable Energy Lab., Golden, CO (United States)
• OSTI ID: 140221
• Report Number(s): NREL/CP--200-5768-Vol.2; CONF-9308106--Vol.2; ON: DE94000435
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
BIOMASS
CELLULASE
CELLULOSE
ENGINEERING
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ETHANOL
ETHANOL FUELS
FERMENTATION
GLUCOSE
GROWTH
PH VALUE
PRODUCTION
PRODUCTIVITY
RENEWABLE ENERGY SOURCES
SACCHARIFICATION
SACCHAROMYCES CEREVISIAE
STIMULATION
SYNERGISM
TEMPERATURE DEPENDENCE