Numerical modelling of heat loss through the cover in the anaerobic digester

Anaerobic digestion is the biological degradation of biomass in oxygen-free environments. The main product of this process is biogas, rich in CH4 and CO2. Understanding the heat loss characteristic of biogas digester (BD) is important to put these technologies into application. Biogas digester may obtain assumed gas production in cold environmental when the optimal fermentation temperature is maintained. It requires heating system and insulation technologies. Here 2-D axisymmetric steady heat transfer model coupled with surrounding soil was built to calculate heat loss of HBD for a real biogas plant located in north-eastern Poland. A sample to determine the effect of air flow between the membranes of the BD cover on the heat losses has been presented.