Investigation of asphalt (bitumen)-fuelled chemical looping combustion using durable copper-based oxygen carrier

Bitumen is a liquid fuel recovered from Alberta oil sands by mining or enhanced oil recovery methods, depending on the depth of the deposits. Steam is a typical in-situ enhanced oil recovery agent used to extract bitumen from underground oil reservoirs with minor surface disturbance. The CO2 emissions from natural gas steam boilers for enhanced oil recovery have been steadily increasing. As a result, ICSET of WKU and Cenovus have been conducting research into whether bitumen is a viable alternative fuel for chemical looping combustion (CLC), which is a CO2 capture ready technology. Major progress on the process development included preparation of advanced oxygen carriers, and hot-model evaluation of prepared oxygen carriers in a benchscale cyclic CLC reactor. Experiments carried out so far have indicated that copper-based oxygen carrier could generate high purity CO2 for sequestration with quick kinetics. Major concerns on low melting point of copper-based oxygen carrier could be largely eliminated by adding minimal amounts of stabilization constituents during oxygen carrier preparation. Steam is found to be a good reagent to prevent carbon deposit on copper-based oxygen carrier during the cyclic operation of CLC. Preliminary tests in our bench scale cyclic reactor have indicated the sulfur constituents in bitumen would be converted to SO2 and it would remain in the fuel reactor gas phase.