Commercial production of fuel ethanol involves fermentation of sugars-currently from corn grain and grain sorghum in the U.S. or sugarcane in tropical regions such as Brazil, and in the future from lignocellulose materials such as grasses, crop residues, and wood.
An alternative approach to fermentation is to produce ethanol (and other biofuels) from syngas produced by the gasification (partial oxidation at high temperatures) of biomass resources. The syngas can then be converted to biofuels such as methanol, ethanol and hydrogen using either a metal catalyst or a microbial catalyst (e.g. bacteria). The use of metal catalysts is a reliable technology and currently is used in industry to produce a variety of biofuels and chemicals. Several microorganisms are capable of consuming syngas producing chemicals such as ethanol.
The gasification process can potentially utilize the entire biomass feedstock (not just the sugar component as with fermentation which can provide a greater conversion efficiency of biomass to energy or chemicals.