{{Short description, Ethanol produced from coalstockEthanol from coal is the
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...
produced using
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when dea ...
as its carbon source. The anaerobic bacterium ''
Clostridium ljungdahlii
''Clostridium ljungdahlii'' is an anaerobic, rod-shaped, motile, endospore-forming, gram-positive bacterium. It is named after the biochemist Lars G. Ljungdahl. When originally harvested from the waste matter of animals, it tended to produce acet ...
'' produces ethanol and
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
from CO, CO2, and H2 in synthesis gas. Early studies with ''C. ljungdahlii'' showed that relatively high concentrations of ethanol were produced. This process involves three main steps:
#Gasification: Thermal gasification at temperatures of up to 2,200°F in a reducing, very low oxygen atmosphere transforms organic materials into simple CO, CO2 and H2 gases.
#Fermentation: The acetogenic ''C. ljungdahlii'' convert the carbon monoxide into ethanol.
#Distillation: Ethanol is separated from hydrogen and water.