Bio-catalytic upgrading of heavy and pyrolysis oils: optioneering of fossil, biorefined, and renewable resources

摘要

As fossil fuels deplete, attention is turning to environmentally-damaging extraction methods to access and use carbon-emitting heavy oil and bitumen-derived fuels. In situ catalytic upgrading can use precious metals (PMs), such as platinum and palladium, in a once-through process. PM catalysts are efficient and clean at decreasing oil viscosity, but prohibitively expensive, and their sacrificial single use squanders limited PM resources. Current developments involve the recovery of otherwise-lost PMs from secondary sources using bacteria, to make low grade, effective, biologically based nanoscale sacrificial catalysts. For carbon neutral alternatives to fossil oils pyrolysis oil from biomass (wood/algae) can produce comparable liquid fuels after upgrading and refining.A comparative assessment shows biorefined catalysts to be comparably effective to commercial catalysts in heavy oil upgrading, with less fouling via accumulated 'coke', whereas pyrolysis oils have less environmental impact via upgrading using commercial catalyst. This is attributable to the biorefining of the bio-PM neo-catalyst from secondary waste sources being more resource-intensive than that of commercial catalysts. Each of the production pathways are assessed and quantified within a life cycle analysis, which will underpin respective business cases taking into account both environmental and techno-economic factors.