Thermal Conductivity of Olive Cake Compost (OCC) as Affected by Moisture and Density: An Experimental and Mathematical Modeling

Abstract The behaviors of bioactive compounds treating gaseous pollutants in biofilters and in the compost used as soil amendment and in green roof buildings are controlled by their thermal properties. There is a lack of information on thermal conductivity of olive cake compost (OCC), K as affected by water content and bulk density. Thermal conductivities (K) of 40 samples of (OCC) were determined experimentally at bulk densities (400–950 kg/m3) and moisture contents (10%–90%) using a single thermal probe method. The results showed that thermal conductivity increased linearly as water content, and bulk density increased and with a decrease in air filled porosity. Simple linear relationships were developed between compost thermal conductivity and dry bulk density and the degree of saturation. The experimental values were close to those reported recently for leaf compost and green roof soils. The compost at water content of 90% showed the highest thermal conductivity (K) of 0.60 W/m.k, which indicate that compost, can be used as good cheep insulator in geothermal heat storage application and as an additional echo-friendly insulation layer in green roof building which might be considered as a good means of passive energy saving there.