Life Cycle Greenhouse Gas Emissions of Current Oil Sands Technologies: Surface Mining and <i>In Situ</i> Applications

Life cycle greenhouse gas (GHG) emissions associated with two major recovery and extraction processes currently utilized in Alberta’s oil sands, surface mining and <i>in situ,</i> are quantified. Process modules are developed and integrated into a life cycle model-GHOST <b>(G</b>reen<b>H</b>ouse gas emissions of current <b>O</b>il <b>S</b>ands <b>T</b>echnologies) developed in prior work. Recovery and extraction of bitumen through surface mining and <i>in situ</i> processes result in 3–9 and 9–16 g CO₂eq/MJ bitumen, respectively; upgrading emissions are an additional 6–17 g CO₂eq/MJ synthetic crude oil (SCO) (all results are on a HHV basis). Although a high degree of variability exists in well-to-wheel emissions due to differences in technologies employed, operating conditions, and product characteristics, the surface mining dilbit and the <i>in situ</i> SCO pathways have the lowest and highest emissions, 88 and 120 g CO₂eq/MJ reformulated gasoline. Through the use of improved data obtained from operating oil sands projects, we present ranges of emissions that overlap with emissions in literature for conventional crude oil. An increased focus is recommended in policy discussions on understanding interproject variability of emissions of both oil sands and conventional crudes, as this has not been adequately represented in previous studies