ExxonMobil Research and Engineering Company, Annandale, New Jersey 08801, USA.
Environ Sci Technol. 2013 May 7;47(9):4896-903. doi: 10.1021/es305162w. Epub 2013 Apr 16.
We present results of a life cycle assessment (LCA) of Marcellus shale gas used for power generation. The analysis employs the most extensive data set of any LCA of shale gas to date, encompassing data from actual gas production and power generation operations. Results indicate that a typical Marcellus gas life cycle yields 466 kg CO2eq/MWh (80% confidence interval: 450-567 kg CO2eq/MWh) of greenhouse gas (GHG) emissions and 224 gal/MWh (80% CI: 185-305 gal/MWh) of freshwater consumption. Operations associated with hydraulic fracturing constitute only 1.2% of the life cycle GHG emissions, and 6.2% of the life cycle freshwater consumption. These results are influenced most strongly by the estimated ultimate recovery (EUR) of the well and the power plant efficiency: increase in either quantity will reduce both life cycle freshwater consumption and GHG emissions relative to power generated at the plant. We conclude by comparing the life cycle impacts of Marcellus gas and U.S. coal: The carbon footprint of Marcellus gas is 53% (80% CI: 44-61%) lower than coal, and its freshwater consumption is about 50% of coal. We conclude that substantial GHG reductions and freshwater savings may result from the replacement of coal-fired power generation with gas-fired power generation.
我们呈现了一项关于用于发电的马塞勒斯页岩气的生命周期评估 (LCA) 的结果。该分析采用了迄今为止任何页岩气 LCA 中最广泛的数据集，涵盖了实际天然气生产和发电运营的数据。结果表明，典型的马塞勒斯天然气生命周期会产生 466 千克二氧化碳当量/MWh（80%置信区间：450-567 千克二氧化碳当量/MWh）的温室气体 (GHG) 排放和 224 加仑/MWh（80%CI：185-305 加仑/MWh）的淡水消耗。水力压裂作业仅占生命周期 GHG 排放的 1.2%，占生命周期淡水消耗的 6.2%。这些结果受井的最终预估产量 (EUR) 和电厂效率的影响最大：这两个数量的增加都将减少相对于电厂发电的生命周期淡水消耗和 GHG 排放。最后，我们通过比较马塞勒斯气和美国煤的生命周期影响得出结论：马塞勒斯气的碳足迹比煤低 53%（80%CI：44-61%），其淡水消耗约为煤的 50%。我们得出结论，通过用燃气发电取代燃煤发电，可能会实现大量的 GHG 减排和淡水节约。
