BIOGAS PRODUCTION FROM THE ALTERNATIVE CROP SILPHIUM PERFOLIATUM L.

摘要

Silphium perfoliatum L. is a tall-growing, flowering, perennial plant that is being considered as an alternative energy crop to maize. The aim of this study was to investigate the potential of silphium for biogas production in Austria. Silphium was grown in 4 different sites, and the silphium harvest yields were higher than maize in all locations in 2013, although in 2014, some sites had lower and some higher silphium harvest yields than maize. The biochemical methane potential (BMP) on an organic dry matter basis from silphium was lower than for maize, with an earlier harvest increasing the BMP. However, with the higher harvest yields, the methane yield per hectare was similar for maize and silphium. Thermal pretreatment at 160 °C did not improve the BMP of silphium. However, during continuous experiments, digesters fed pretreated silphium produced up to 25% more methane than those fed with untreated silphium. In summary, silphium was found to be a good substrate for biogas production in Austria.