Anaerobic Digestion
Mesophilic and thermophilic anaerobic digestion
There are two conventional operational temperature levels - mesophilic (35 -40°C) and thermophilic (50 -60°C). The temperature difference affects the rate of decomposition, liquid and solid separation, pathogen control, thermal input, retention time of wastes, and the capital investment of a system.
Although the thermophilic process is more expensive to operate due to the higher temperature, it has following advantages:
- faster rate of decomposition and liquid and solid separation;
- sterilization of residues; and
- higher methane yield