Department of Mechanical Engineering, 10-263 Donadeo Innovation Centre for Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada.
Environ Sci Technol. 2017 Jan 3;51(1):680-691. doi: 10.1021/acs.est.6b02889. Epub 2016 Dec 15.
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 750 000 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 100 000 to 800 000 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.
原油目前主要通过管道和铁路从开采地点运往世界各地的炼油厂。本研究评估了三种情景（合成原油和稀释油，有无稀释剂返回）下每年 75 万桶艾伯塔省沥青的运输距离为 3000 公里的能源利用和温室气体（GHG）排放，以确定哪种方法的环境影响更小。每个情景都有管道和铁路两种运输方式，而没有稀释剂返回的稀释油情景还有另一种需要稀释剂的加热沥青运输方式。使用基于 Excel 的自下而上模型，根据工程第一原理计算每个过程的质量和能量平衡。结果表明，与铁路运输相比，管道运输产生的温室气体排放量减少了 61%至 77%。随着运输能力从 10 万桶/天增加到 800 万桶/天，铁路和管道的温室气体排放量分别减少了 15%和 73%。进行了蒙特卡罗模拟以确定排放的不确定性，发现管道的不确定性更大（高达±73%），而铁路的不确定性更小（高达±28%）。不确定性范围不重叠，因此证实了管道的温室气体排放量较低，这对于进行管道审查的政策制定者来说是重要的信息。
