The biogas production peak of 750 L kg VS1 was reached at an OLR of 3 kg VS m3 d1 in the thermophilic process. The mesophilic process produced the maximum volume of biogas
(689 L kg VS1) at an OLR of 5 kg VS m3 d1. Above this OLR, the yield of biogas per kg of volatile solids decreased at both temperatures, although the cumulative generation of biogas continued to
increase up to an OLR of 10 kg VS m3 d1.