Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.
AkerBP, Lysaker 1366, Norway.
Environ Sci Technol. 2023 Jul 4;57(26):9459-9473. doi: 10.1021/acs.est.2c08652. Epub 2023 Jun 16.
Carbon capture and storage (CCS) is an important component in many national net-zero strategies. Ensuring that CO can be safely and economically stored in geological systems is critical. To date, CCS research has focused on the physiochemical behavior of CO, yet there has been little consideration of the subsurface microbial impact on CO storage. However, recent discoveries have shown that microbial processes (e.g., methanogenesis) can be significant. Importantly, methanogenesis may modify the fluid composition and the fluid dynamics within the storage reservoir. Such changes may subsequently reduce the volume of CO that can be stored and change the mobility and future trapping systematics of the evolved supercritical fluid. Here, we review the current knowledge of how microbial methanogenesis could impact CO storage, including the potential scale of methanogenesis and the range of geologic settings under which this process operates. We find that methanogenesis is possible in all storage target types; however, the kinetics and energetics of methanogenesis will likely be limited by H generation. We expect that the bioavailability of H (and thus potential of microbial methanogenesis) will be greatest in depleted hydrocarbon fields and least within saline aquifers. We propose that additional integrated monitoring requirements are needed for CO storage to trace any biogeochemical processes including baseline, temporal, and spatial studies. Finally, we suggest areas where further research should be targeted in order to fully understand microbial methanogenesis in CO storage sites and its potential impact.
碳捕集与封存（CCS）是许多国家净零战略的重要组成部分。确保 CO 能够安全、经济地储存在地质系统中至关重要。迄今为止，CCS 研究主要集中在 CO 的物理化学行为上，但对地下微生物对 CO 储存的影响关注甚少。然而，最近的发现表明，微生物过程（例如，产甲烷作用）可能非常重要。重要的是，产甲烷作用可能会改变储存库中的流体组成和流体动力学。这些变化可能会随后减少可储存的 CO 量，并改变演化超临界流体的迁移性和未来捕集系统。在这里，我们回顾了微生物产甲烷作用如何影响 CO 储存的现有知识，包括产甲烷作用的潜在规模以及该过程作用的地质环境范围。我们发现产甲烷作用在所有储存目标类型中都是可能的；然而，产甲烷作用的动力学和热力学可能受到 H 生成的限制。我们预计，在枯竭的烃类储层中，H 的生物利用度（因此微生物产甲烷作用的潜力）最大，而在盐含水层中最小。我们建议 CO 储存需要额外的综合监测要求，以追踪包括基线、时间和空间研究在内的任何生物地球化学过程。最后，我们建议应针对哪些领域进行进一步的研究，以便充分了解 CO 储存点中的微生物产甲烷作用及其潜在影响。
