Composition of corncobs as a substrate for fermentation of biofuels

Lignocellulosic residues as for instance corncobs can be used as substrates for the production of biofuels. The corncobs are usually pre-treated in a thermal-physical step (steam explosion) before enzymatic hydrolysis. The pre-treatment process increases the accessibility of the raw material for the hydrolysis. The products of the hydrolyses are used as substrates for the fermentation of bio-ethanol. As an alternative, the hydrolysates could be used for the fermentation of oleaginous yeasts. These yeasts produce and accumulate lipids from glucose during growth. For the energetic use in the form of bio-diesel, the lipids can be converted into fatty acid methyl esters (FAME) in the same way as vegetable oils. The fibre composition of the raw material was determined in regard to the proportions of cellulose, hemicellulose und lignin. It was investigated whether different corn varieties show varying compositions. The fibre compositions before the pre-treatment of ten different varieties of corncobs (from locations in Upper Austria) were determined. No significant differences were observed (cellulose: 38.8% ± 2.5%, hemicellulose: 44.4% ± 5.2%, lignin: 11.9% ± 2.3% in the dry matter).