METHANE FERMENTATION OF WOODY BIOMASS

Woody biomass has been previously considered to be highly refractile to anaerobic digestion without extensive pretreatment. However, this study has demonstrated that high rates and ultimate methane yields may be obtained in batch assays without pretreatment, other than some particle size reduction. In a survey of 32 woody samples (chiefly willow and popular species grown in a wood-grass system) significant yields of methane (greater-than-or-equal-to 0.25 liters g-1 volatile solids added) were obtained from 19 of the samples, while the yield from 3 of the samples (Salix eriocephala, S. exigua and Platanus occidentalis) exceeded 0.30 liters g-1 volatile solids added. The commercial production of energy through the biological gasification of woody biomass may therefore represent a viable alternative for energy production in the United States. An interesting feature of this study was the biphasic nature of methane production from two-thirds of the samples tested.