Evaluation of the Greenhouse Gas Emissions of Oil Sands Upgrading Technologies Using a Novel Life Cycle-based Model

As the production of oil sands bitumen and associated final products (e.g., transportation fuels) continues to grow, so do the environmental impacts associated with the life cycle of fuel production and use. This has motivated research on developing novel analytical methods that model these impacts on a life cycle basis. Upgrading generated 23% of the greenhouse gas (GHG) emissions from oil sands operations or 2% of Canada’s GHG emissions in 2016. Upgrading is a stage in the production of oil sands-derived transportation fuels that transforms bitumen into higher value products, most of them refinery feedstocks. A novel life cycle-based model, the Oil Sands Technologies for Upgrading Model (OSTUM), that assesses the direct and indirect energy use and GHG intensities of current and emerging upgrading technologies, was developed and implemented using publicly available data. OSTUM is applied to commercial upgrading technologies operating in Canada in 2018: delayed coking based- (DC), hydroconversion based- (HC), and combined hydroconversion and fluid coking based upgrading (HC/FC). Two emerging partial upgrading technologies are also modeled: the HI-Q® Process and EST technology. These latter applications demonstrate OSTUM’s flexibility to produce adequate assessments as the oil sands industry evolves. DC’s baseline intensity is 8.5 grams of carbon dioxide equivalent per megajoule of synthetic crude oil (g CO2e/MJ SCO) and range is 6.3–11.2 g CO2e/MJ SCO. HC’s baseline intensity is 10.8 g CO2e/MJ SCO (range: 8.6-14.3 g CO2e/MJ SCO) and HC/FC’s is 12.2 g CO2e/MJ SCO (range: 9.7-14.8 g CO2e/MJ SCO). The baseline, low and high scenario GHG intensities for HI-Q® are 3.7, 2.3 and 6.4 g CO2e/MJ of partially upgraded bitumen (PUB), respectively, and 8.3, 6.6 and 12.3 g CO2e/MJ PUB for EST. Contributions include 1) the development of a framework to systematically assess/compare the GHG intensities of upgrading technologies using consistent boundaries, assumptions, sources, and methodologies; 2) comprehensive and transparent results obtained with a well-documented model; 3) improved characterization of emission sources/drivers of variability; 4) improved estimation of hydrogen consumption; and 5) estimation of GHG intensities of upgrading co-products of different qualities. OSTUM can provide insight and assist stakeholders in regulating and mitigating upgrading GHG emissions.Ph.D.2021-11-14 00:00:0