At scale, renewable natural gas systems could be climate intensive: the influence of methane feedstock and leakage rates
At scale, renewable natural gas systems could be climate intensive: the influence of methane feedstock and leakage rates
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从规模上看，可再生天然气系统可能是气候密集型的：甲烷原料和泄漏率的影响
DOI：
10.1088/1748-9326/ab9335
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发表时间：
2020
影响因子：
6.7
通讯作者：
E. Grubert
中科院分区：
文献类型：
--
作者：
E. Grubert
可再生天然气（RNG）是一种基本上由纯甲烷组成的燃料，通常源自气候中性（例如生物源或捕获）二氧化碳（CO2）。RNG被提议作为化石天然气（FNG）的气候友好型直接替代品，其目标是使不同的天然气用户能够在不进行重大基础设施大修的情况下继续运营。这种替代品对气候无害的假设依赖于一个不太可能满足的主要条件：即可再生天然气是由否则会排放到大气中的废弃甲烷制造的。在实践中，可捕获的废物甲烷是非常有限的，更有可能从火炬转移，而不是从直接大气释放在气候意识的政策背景下，这意味着RNG系统需要比火炬更具破坏性效率，以提供气候效益与可能的替代管理策略。假设需求水平与使用现有FNG基础设施的目标一致，RNG可能来自有意生产或从火炬转移的甲烷，因此基本上任何甲烷泄漏都是气候附加的。此外，在脱碳系统中，RNG可能会与比FNG排放量更低的资源竞争，因此随着时间的推移，净排放效益更少。预计的泄漏具有气候意义：对沼气生产和升级设施甲烷泄漏的文献估计表明，泄漏在2%-4%的范围内（质量基础），高达15%。决策者应考虑到，在合理的渗漏和需求假设下，可再生天然气可能是气候密集型的。
Renewable natural gas (RNG) is a fuel comprised of essentially pure methane, usually derived from climate-neutral (e.g. biogenic or captured) carbon dioxide (CO2). RNG is proposed as a climate friendly direct substitute for fossil natural gas (FNG), with the goal of enabling diverse natural gas users to continue operating without substantial infrastructure overhauls. The assumption that such substitution is climate friendly relies on a major condition that is unlikely to be met: namely, that RNG is manufactured from waste methane that would otherwise have been emitted to the atmosphere. In practice, capturable waste methane is extremely limited and is more likely to be diverted from a flare than from direct atmospheric release in a climate-conscious policy context, which means that RNG systems need to be more destructively efficient than a flare to provide climate benefits versus the likely alternative management strategy. Assuming demand levels consistent with the goal of using existing FNG infrastructure, RNG is likely to be derived from methane that is either intentionally produced or diverted from a flare, so essentially any methane leakage is climate additional. Further, in a decarbonizing system, RNG will likely compete with lower-emissions resources than FNG and thus provides fewer net emissions benefits over time. Anticipated leakage is climatically significant: literature estimates for methane leakage from biogas production and upgrading facilities suggest that leakage is in the 2%–4% range (mass basis), up to as much as 15%. Policy makers should consider that under reasonable leakage and demand assumptions, RNG could be climate intensive.
影响因子：
9
作者：
McCauley, Darren;Heffron, Raphael
通讯作者：
Heffron, Raphael