Selective solvent delignification for fermentation enhancement
Cellulose and hemicellulose in renewable biomass resources such as cornstover and wheat straw have been examined as substrates for the production of ethanol. A mixed culture of selected strains of Clostridium thermocellum and Clostridium thermosaccharolyticumare used to accomplish both the hydrolysis and fermentation of these carbohydrates in a single step. However, lignin and related phenolic materials are shown to diminish the rate, extent, and yield at which these carbohydrates can be utilized for ethanol production. In order to overcome this problem, a selective solvent pretreatment with alkaline-ethanol-water mixtures was examined for the delignification of cellulosic biomass under conditions where very little loss of fermentable carbohyrates results. Under optimal conditions, up to 67% of the initial lignin in cornstover can be extracted while 95% of the ..cap alpha..-cellulose and pentosan carbohydrates remain insoluble. Subsequent mixed culture fermentation of the treated material has shown a 400% increase in the rate of degradation and greater than 85% utilization of the substrate. The effects of various extraction parameters on delignification kinetics and subsequent fermentation performance are discussed.
- Research Organization:
- Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- OSTI ID:
- 5941563
- Journal Information:
- Biotechnol. Bioeng.; (United States), Vol. XXV:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AGRICULTURAL WASTES
DELIGNIFICATION
ETHANOL
PRODUCTION
FERMENTATION
OPTIMIZATION
RENEWABLE ENERGY SOURCES
BIOMASS
CARBOHYDRATES
CELLULOSE
CLOSTRIDIUM
CLOSTRIDIUM THERMOCELLUM
HEMICELLULOSE
HYDROLYSIS
KINETICS
MAIZE
MIXTURES
SOLVENTS
STRAW
SUBSTRATES
WATER
ALCOHOLS
BACTERIA
BIOCONVERSION
CEREALS
CHEMICAL REACTIONS
DECOMPOSITION
DISPERSIONS
ENERGY SOURCES
GRAMINEAE
GRASS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LYSIS
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC WASTES
OXYGEN COMPOUNDS
PLANTS
POLYSACCHARIDES
SACCHARIDES
SOLVOLYSIS
WASTES
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140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)