Testing of thermal properties of compost from municipal waste with a view to using it as a renewable, low temperature heat source.

To determine how much heat may be recovered from a composting process, first it is necessary to know the heat production during the high temperature phase and characteristic values of the thermal conductivity coefficient for compost. The composting process was monitored in laboratory experiments. During the high temperature phase an average 1136kJ/kg of heat was released (but generally it was around 900kJ/kg). An average of 37.4% of that heat resulted from total bio-oxidation of organic compounds, assumed to be carbohydrates. The values of conductivity coefficient were from 0.150 to 0.309W/mK and depended on the temperature, humidity, density and age of compost.