Life cycle GHG emissions assessment of vanadium recovery from spent catalysts from bitumen upgraders

Bitumen from oil sands is a key source of fossil fuels. Bitumen is upgraded to produce synthetic crude oil, which is subsequently refined. The amount of vanadium in bitumen upgrading spent catalyst is substantial. Vanadium plays a vital role in steel production, chemical processes, and energy storage through its use in batteries, making it a valuable commodity worldwide. Recovering this metal from bitumen can be a profitable activity that could help contribute to global demand. Besides the economics of the process, the environmental impact should be addressed. However, details on the greenhouse gas (GHG) emissions generated during the process are not available. Therefore, we conducted a life cycle assessment of recovering vanadium from spent catalyst generated during bitumen upgrading. We developed a data-intensive model to estimate the GHG emissions from each life cycle stage of vanadium recovery from bitumen upgraders. The estimated life cycle GHG emissions are 11.8 kg CO2eq/kg V2O5. Of the total GHG emissions, 69 % are indirect and 31 % are direct emissions. If we consider the displacement of co-produced metals like molybdenum and alumina, the life cycle GHG emissions of the production system would drop to 0.63 kg CO2eq/kg V2O5. Sensitivity and uncertainty analyses show that the emission factor of electricity production, the specific energy consumption in the electric arc furnace, and the saltto-spent catalyst ratio are the parameters with the most significant impact on the GHG emissions. Coupling a vanadium recovery plant with a bitumen upgrader is worthy of consideration because of the potential environmental benefits of the process.