Ethanol from lignocellulose - An overview

Conference · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5406201

Wright, J D

Ethanol, a liquid fuel compatible with today's transportation system, can be produced by biological processes from lingocellulosic feedstocks. Biomass is an attractive feedstock for ethanol production because it is available in large quantities at low cost. Biological processes are very efficient, but each fraction of the lignocellulosic feedstock must be processed separately. Cellulose (a crystalline polymer of glucose), the structural core, comprises 40% of the feedstock. It is difficult to hydrolyze (break down) into glucose, but once formed, the glucose is readily fermented to ethanol. Cellulose can be hydrolyzed with either acid or enzymatic catalysts. Using acids, the chief problem is that conditions severe enough to promote hydrolysis also degrade the glucose, resulting in low (55%-80%) yields. Enzymatic processes are potentially much more efficient because enzymes catalyze only the hydrolysis reaction. However, these processes are much newer and less developed. Research is required to develop methods to make lignocellulose more digestible, to produce more active enzymes at lower cost, and to develop methods of hydrolysis where enzyme action is not inhibited by reaction end products. Approximately 30% of the feedstock is hemicellulose, which is largely made of xylan (a polymer of xylose). Xylan is easily hydrolyzed, but it is difficult to ferment to ethanol. Several potential methods of fermentation have been identified, but it is not yet clear which is the most promising. Lignin, the final major component, is a phenolic polymer that cannot be fermented to ethanol. However, it can be broken down to phenolic monomers, hydrotreated, and reacted with methanol to produce methyl aryl ethers, a high-octane gasoline additive.

• OSTI ID: 5406201
• Report Number(s): CONF-870822-
• Resource Relation: Conference: American Institute of Chemical Engineers summer national meeting, Minneapolis, MN, USA, 16 Aug 1987; Other Information: Technical Paper 24A
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
59 BASIC BIOLOGICAL SCIENCES
ETHANOL FUELS
MANUFACTURING
LIGNIN
ENZYMATIC HYDROLYSIS
PROCESSING
BIOLOGICAL PATHWAYS
BIOMASS
BIOTECHNOLOGY
CATALYSTS
CELLULOSE
CHEMICAL FEEDSTOCKS
CHEMICAL REACTIONS
FERMENTATION
GLUCOSE
LIQUID FUELS
PHENOLS
POLYMERS
TECHNOLOGY ASSESSMENT
ALCOHOL FUELS
ALDEHYDES
AROMATICS
BIOCONVERSION
CARBOHYDRATES
DECOMPOSITION
ENERGY SOURCES
FUELS
HEXOSES
HYDROLYSIS
HYDROXY COMPOUNDS
LYSIS
MONOSACCHARIDES
ORGANIC COMPOUNDS
POLYSACCHARIDES
RENEWABLE ENERGY SOURCES
SACCHARIDES
SOLVOLYSIS
SYNTHETIC FUELS
090222* - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989)
550200 - Biochemistry