RESUMO
Crude oil is currently transported primarily by pipelines and rail from extraction sites to refineries around the world. This research evaluates energy use and greenhouse gas (GHG) emissions for three scenarios (synthetic crude oil and dilbit with and without diluent return) in which 750â¯000 bpd of Alberta's bitumen is transported 3000 km to determine which method has a lower environmental impact. Each scenario has a pipeline and rail pathway, and the dilbit without diluent return scenario has an additional heated bitumen pathway, which does not require diluent. An Excel based bottom-up model is developed using engineering first-principles to calculate mass and energy balances for each process. Results show that pipeline transportation produced between 61% and 77% fewer GHG emissions than by rail. The GHG emissions decreased by 15% and 73% for rail and pipelines as the capacity increased from 100â¯000 to 800â¯000 bpd. A Monte Carlo simulation was performed to determine the uncertainty in the emissions and found that the uncertainty was larger for pipelines (up to ±73%) and smaller for rail (up to ±28%). The uncertainty ranges do not overlap, thus confirming that pipelines have lower GHG emissions, which is important information for policy makers conducting pipeline reviews.
