Kinetic models for the thermal cracking of Athabasca bitumen: The effect of the sand matrix

Athabasca bitumen and bitumen-derived products were thermally cracked with and without sand at 360, 400 and 420 °C. The products were separated into six pseudo-components: coke, asphaltenes, heavy oils, middle oils, light oils and gases. The data from cracking bitumen-sand mixtures were compared with data obtained from this work and from the literature on bitumen cracking in the absence of sand. The yields of coke and gases from cracking bitumen-sand mixtures were higher than those from cracking bitumen alone. The presence of sand also affected the yields of the other pseudo-components. Two kinetic models were developed to describe the results. The activation energies for the reactions involved in cracking bitumen-sand mixtures were lower than those involved in cracking bitumen alone. The nature of the effect of sand on the cracking of bitumen is discussed.