一项新的研究指出，在美国，甲烷排放的大部分来源几乎都可以追溯到“超级排放”的天然气井身上。“我们发现天然气泄漏时遵循一个50/5的原则，也就是说，最大那5%的泄漏源所释放的甲烷却占到泄漏总量的50%以上。”该研究的作者，斯坦福大学能源工程学院的助理教授亚当·布兰德说。研究结果发表在《环境科学与技术》杂志上，布兰德称，研究可能促进政府采取更有效的策略来控制和修复一些重要的泄漏源，通过专注于研究如何修复最大的排放源，可以显著减少泄漏到大气中的甲烷。天然气作为满足美国和全球能源需求的一个重要部分，发挥着桥梁燃料的作用，可以为人们从化石燃料转向可再生能源资源提供一个过度保障。但天然气的主要成分是甲烷，所以即使是小的泄漏，也会对气候变化产生严重影响，因为甲烷是一种强有力的温室气体——比二氧化碳捕获太阳能的能力要强大约30倍。
The bulk of methane emissions in the United States can be traced to a small number of “super emitting” natural gas wells, according to a new study.
“We’re finding that when it comes to natural gas leaks, a 50/5 rule applies: That is, the largest 5 percent of leaks are typically responsible for more than 50 percent of the total volume of leakage,” said study co-author Adam Brandt, an assistant professor of energy resources engineering at Stanford’s School of Earth, Energy & Environmental Sciences.
The findings, published online in the journal Environmental Science & Technology, could lead to more efficient strategies for sampling emissions and fixing the most significant leaks, said Brandt, who is also a senior fellow at Stanford’s Precourt Institute for Energy. By focusing on finding and fixing the biggest emitters, companies can significantly reduce the amount of methane leaking into the atmosphere.
A bridge fuel
Natural gas is playing an increasingly important role in meeting U.S. and global energy needs and could serve as a “bridge fuel” for countries as they transition from fossil fuels to renewable energy resources. But natural gas consists predominately of methane, so even small leaks from natural gas wells can create large climate concerns because methane is a potent greenhouse gas – it’s about 30 times more effective at trapping solar heat than carbon dioxide over a 100-year period.
