Biological production of ethanol from coal
Researchers at the University of Arkansas have concentrated on a biological approach to coal liquefaction, starting with coal-derived synthesis gas as the raw material. Synthesis gas, a mixture of CO, H{sub 2}, CO{sub 2}, CH{sub 4} and sulfur gases, is first produced using traditional gasification techniques. The CO, CO{sub 2} and H{sub 2} are then converted to ethanol using a bacterial culture of Clostridium ljungdahlii. C. ljungdahlii was initially isolated from animal waste at the University of Arkansas. The bacterium converts CO, CO{sub 2} and H{sub 2} to ethanol and acetate. Ethanol is the desired product if the resultant product stream is to be used as a liquid fuel. However, under normal operating conditions, the wild strain'' produces acetate in favor of ethanol in conjunction with growth in a 20:1 molar ratio. Several factors have been identified that cause the culture to produce ethanol in favor of acetate. These factors include manipulation of the nutrients composition and concentration, the addition of reducing agents or sporulating agents to liquid medium and reduction of the medium pH. Many of these techniques have been demonstrated in batch and continuous culture, both individually and together as multiple parameter experiments. Manipulation of these parameters has led to the realization that acetate is produced in conjunction with growth and energy production, whereas ethanol is produced when growth is minimized and when energy is used instead of produced. The parameters that enhance ethanol production suppress growth and/or produce energy for ultimate use by the cell during ethanol production. The purpose of this report is to present the results of studies aimed at increasing the ethanol concentration in batch and continuous culture. 31 refs., 50 figs., 6 tabs.
- Research Organization:
- Arkansas Univ., Fayetteville, AR (United States). Dept. of Chemical Engineering
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC22-89PC89876
- OSTI ID:
- 5517257
- Report Number(s):
- DOE/PC/89876-T2; ON: DE91014808
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
10 SYNTHETIC FUELS
CLOSTRIDIUM
GROWTH
ETHANOL
CHEMICAL REACTION YIELD
SYNTHESIS GAS
BIOCONVERSION
ACETATES
CARBON MONOXIDE
COAL
CULTURE MEDIA
HYDROGEN
LIQUID FUELS
PARTIAL PRESSURE
PH VALUE
QUANTITY RATIO
ALCOHOLS
BACTERIA
CARBON COMPOUNDS
CARBON OXIDES
CARBONACEOUS MATERIALS
CARBOXYLIC ACID SALTS
CHALCOGENIDES
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
GASES
HYDROXY COMPOUNDS
MATERIALS
MICROORGANISMS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
YIELDS
010405* - Coal
Lignite
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550700 - Microbiology
100200 - Synthetic Fuels- Production- (1990-)