Temperature Effect on Methane Production from Field-Scale Digesters
Channel: Livestock & Poultry Environ. Learning Community
Date: 2015-04-30

Full proceedings at: http://www.extension.org/pages/72729 Anaerobic digestion is a process that results in the production of biogas that can be used a renewable source of electricity on-farm or sold to the distribution grid. Temperature is a critical parameter for anaerobic digestion since it influences both system heat requirements and methane production. Although anaerobic digestion can take place under psychrophilic (15-25°C), mesophilic (35-40°C), and thermophilic (50-60°C) conditions, temperatures of 35-37°C are typically recommended for methane production from animal manure. However, digesters require significant amount of heat energy to maintain temperatures at these levels. There is limited information about methane production from dairy digesters at temperatures less than 35°C and results in the literature are presented from laboratory-scale rather than field-scale systems.

The objective of this study was to evaluate the effect of two relatively low digestion temperatures (22 and 28°C) on methane production using replicate continuously-fed, field-scale dairy manure digesters at two organic loading rates. The results were compared with those from identical digesters operated at 35°C.