The effect of temperature on the production of methane from dry
CM was examined at 37, 55, and 65 °C for 9 repeated batches. Although
production of biogas was observed at all temperatures, methane was
not produced in any of the repeated batches at 55 and 65 °C (data not
shown). Therefore, only the results of experiments at 37 °C are
described, as follows. At 37 °C, the highest production of biogas was
observed in the last 2 batches, the 8th and 9th batches, which were
15 l kg− 1 and 19 l kg− 1 CM, respectively (Fig. 1).