†Systems Assessment Group, Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States.
‡Department of Energy Resources Engineering, Stanford University, 367 Panama Street, Green Earth Sciences Building, 065, Stanford, California 94305, United States.
Environ Sci Technol. 2015 Jul 7;49(13):8219-27. doi: 10.1021/acs.est.5b01255. Epub 2015 Jun 25.
Greenhouse gas (GHG) regulations affecting U.S. transportation fuels require holistic examination of the life-cycle emissions of U.S. petroleum feedstocks. With an expanded system boundary that included land disturbance-induced GHG emissions, we estimated well-to-wheels (WTW) GHG emissions of U.S. production of gasoline and diesel sourced from Canadian oil sands. Our analysis was based on detailed characterization of the energy intensities of 27 oil sands projects, representing industrial practices and technological advances since 2008. Four major oil sands production pathways were examined, including bitumen and synthetic crude oil (SCO) from both surface mining and in situ projects. Pathway-average GHG emissions from oil sands extraction, separation, and upgrading ranged from ∼6.1 to ∼27.3 g CO2 equivalents per megajoule (in lower heating value, CO2e/MJ). This range can be compared to ∼4.4 g CO2e/MJ for U.S. conventional crude oil recovery. Depending on the extraction technology and product type output of oil sands projects, the WTW GHG emissions for gasoline and diesel produced from bitumen and SCO in U.S. refineries were in the range of 100-115 and 99-117 g CO2e/MJ, respectively, representing, on average, about 18% and 21% higher emissions than those derived from U.S. conventional crudes. WTW GHG emissions of gasoline and diesel derived from diluted bitumen ranged from 97 to 103 and 96 to 104 g CO2e/MJ, respectively, showing the effect of diluent use on fuel emissions.
温室气体（GHG）法规影响美国运输燃料，需要全面考察美国石油原料的生命周期排放。我们扩大了系统边界，包括土地干扰引起的温室气体排放，从而估算了源自加拿大油砂的美国汽油和柴油生产的从井口到车轮（WTW）温室气体排放。我们的分析基于对 27 个油砂项目的能源强度的详细特征描述，这些项目代表了自 2008 年以来的工业实践和技术进步。我们考察了四种主要的油砂生产途径，包括露天矿和原地项目生产的沥青和合成原油（SCO）。油砂开采、分离和升级过程的平均温室气体排放量从每兆焦耳（低热值）约 6.1 克至 27.3 克二氧化碳当量（CO2e/MJ）不等。这一范围可与美国常规原油回收的每兆焦耳 4.4 克 CO2e/MJ 相比较。根据油砂项目的开采技术和产品类型，在美国炼油厂生产的沥青和 SCO 制成的汽油和柴油的 WTW 温室气体排放量分别在 100-115 和 99-117 克 CO2e/MJ 范围内，平均比源自美国常规原油的排放量高出约 18%和 21%。稀释沥青制成的汽油和柴油的 WTW 温室气体排放量分别在 97-103 和 96-104 克 CO2e/MJ 范围内，表明了稀释剂使用对燃料排放的影响。
