Measurements of specific heat, thermal conductivity and thermal diffusivity of Utah tar sands

Abstract A constant applied heat flux method has been used to measure the specific heat and thermal conductivity of large samples of Utah (North-west Asphalt Ridge) tar sands as a function of temperature. Independent measurements of density allowed for the calculation of thermal diffusivity. Constituent analysis of the tar sand samples also permitted the calculation of bitumen and sand specific heats. Specific heat of the bitumen was found to increase with temperature from 1.85 to 3.9 kJ kg −1 K −1 for temperatures between 300 and 480 K. Specific heat of the sand matrix increased only slightly, from 0.85 to 1.0 kJ kg −1 K − for the same range of temperature. Corresponding thermal diffusivities for tar sand were found to decrease with temperature, and had a range of 5 · 10 −7 –9 · 10 −7 m 2 s −1 over the measured temperatures. It was concluded that the latent heat of both bitumen and water have a strong influence on the apparent overall specific heat of tar sand.