PARTIAL SUBSTITUTION OF MAIZE SILAGE WITH ACUTODESMUS OBLIQUUS BIOMASS IN CONTINUOUS ANAEROBIC DIGESTERS AT LABORATORY SCALE

摘要

In this study the substitutability of maize silage with Acutodesmus obliquus biomass was investigated. To do this, an existing large-scale biogas plant digesting maize silage and pig slurry was simulated at laboratory scale and run for 270 days at 38 °C. In different operation types 10% and 20% of maize silage VS were substituted with A. obliquus biomass VS. Additionally, reactors were fed with 20% ultrasonicated A. obliquus biomass. Differences in process stability could not be observed. The biogas production decreased at increased concentrations of microalgal biomass. A significant difference between untreated and ultrasonicated algal biomass (both 20%) could not be proven.However, the percentage decrease was lower than the percentage of maize silage VS substituted. Therefore it can be concluded that A. obliuus biomass is anaerobically degradable without any pretreatment.