Repeatability of a laboratory batch method to determine the specific biogas and methane yields

Abstract

To evaluate the potential of a substrate to form biogas, it is essential to have a fast and accurate method to determine the specific biogas yield ( SBY ) and specific methane yield ( SMY ). The objectives of this study were to assess the repeatability of the H ohenheim B iogas Y ield T est ( HBT ) and to assess the influence of sample withdrawal and preparation on the determined SBY and SMY . Samples of dried maize whole plant material, maize cob, and power fodder, with up to six different treatments for preparation, were analyzed for their SBY and SMY using a discontinuous fermentation assay. Further, chemical composition of the whole plant sample was examined and different calculation models were used to predict SMY . The HBT showed a strong repeatability and a high precision for SMY . Two of the tested chemical composition models showed a satisfactory performance compared to the mean of the measured methane values. Significant effects caused by different sample treatments could be observed.