A semi-continuously operated anaerobic digestion reactor (fed
once per day) with an operating volume of 150 L was used for two
consecutive production cycles under differing temperature conditions;
the mesophilic digestion process was held at 35e37 C for 19
weeks (September 2007eFebruary 2008), and the following thermophilic
digestion process was held at 55e57 C for 20 weeks
(AprileSeptember 2008)