The geomicrobiology of hydrogen storage in geological materials

为了在英国推广地下储氢，需要了解地质储氢地点本身以及在这些地下环境中发生的氢与微生物相互作用的信息。主要在英国，需要用于储氢的地质构造是溶蚀洞穴（储存在盐矿床中）或多孔介质，如含水层和枯竭的油气田（DOGF）。地下微生物过程、氢与岩石物质之间的化学和矿物学反应会产生不需要的副产物（硫化氢、甲烷、生物堵塞），导致返回气体中含有杂质，或改变洞穴/储层的非均质性。有一些已知的微生物（如产甲烷菌、硫还原菌、同质产氧菌）以氢为能源，但尚不清楚它们的菌落如何相互作用/竞争，也不清楚在地下占主导地位的过程/机制。现有的地下微生物过程知识是有限的。对于大规模地下储氢，提出了三个区域：盐洞、枯竭油气藏和含盐含水层。开展实验工作，了解氢微生物相互作用及其对储层矿物学地球化学反应性的影响。目前，全球大部分氢气和大部分天然气都储存在盐洞中。随着氢气使用量的扩大，要么扩大规模，要么将天然气储存转化为氢气。然而，关于盐穴中的微生物如何与氢气相互作用的研究有限。这很重要，因为它可以降低氢气的产量和纯度，这可能导致需要额外的成本进行储存后净化。多孔介质（DOGF和含盐含水层）对于绿色氢尤其有利，因为没有大规模的管道基础设施，盐洞储存不容易获得，但地下储层就在附近（例如，海上风力产生绿色氢并直接进入地下储存）。提供大量氢气的多孔介质与盐穴和北海现有的管道网络竞争，可以重新利用/改装以输送氢气。由于北海油气行业提供了充足的信息，人们已经对其进行了地质调查，了解了孔隙度和渗透率的条件，这两个因素对任何类型的多孔介质储气库都非常重要。微生物将通过在NU-OMICS测序服务（Northumbria University）的Illumina MiSeq平台上进行16s rRNA测序来确定。将在氢微生物相互作用实验前后进行岩石学分析，以确定储层是否发生任何矿物学变化（例如矿物溶解或沉淀）。如果时间允许，潜在的地质储存地点将在英国各地进行研究，包括陆上和海上。特别是在英国大陆架上研究二叠纪和三叠纪盐沉积、含盐含水层和DOGF。

To rollout UK hydrogen storage in the subsurface, information is needed regarding the geological storage site itself and the hydrogen - microbe interactions that occur in these subsurface environments. Primarily in the UK, geological formations desired for hydrogen storage are caverns by dissolution (storage in salt deposits) or in porous media, such as aquifers and depleted oil and gas fields (DOGF). Subsurface microbial processes, chemical and mineralogical reactions between hydrogen and the rock material can produce unwanted by products (hydrogen sulphide, methane, bio clogging) leading to impurities in the returned gas or changes in cavern/reservoir heterogeneity. There are known microbes (e.g., methanogens, sulphur reducing bacteria, homoacetogens) that consume hydrogen as an energy source, but it is not clear how their colonies interact/compete with one another or the processes/mechanisms which dominate in the subsurface. Existing knowledge of subsurface microbial process is limited. For large scale underground hydrogen storage three areas are proposed: salt caverns, depleted oil and gas reservoirs and saline aquifers. Experimental work will be carried out to understand the hydrogen microbe interactions and their effects on the geochemical reactivity on reservoir mineralogy. Salt caverns currently act as storage for most of the hydrogen and a large proportion of natural gas globally. Either scaling up or converting natural gas stores to hydrogen is likely to happen as hydrogen usage expands. However, there are limited studies on how microbes in the salt caverns interact with the hydrogen gas. This is important as it could reduce both the yield and purity of hydrogen which could lead to post storage purification being required at additional costs. Porous media (DOGF and saline aquifers) are especially advantageous for green hydrogen where salt cavern storage is not easily accessible without large scale pipeline infrastructure, but subsurface reservoirs are nearby, (e.g., offshore wind to produce green hydrogen and straight to underground storage). Porous media offering huge volumes of hydrogen gas competed to salt caverns and an already existing pipeline network in the North Sea can be repurposed/refitted to deliver hydrogen. With ample information from the oil and gas industry in the North Sea, geology is already surveyed with known conditions of porosity and permeability, two factors hugely important for any type of porous media gas storage. Microorganisms will be determined through 16s rRNA sequencing conducted on Illumina MiSeq platform at the NU-OMICS sequencing service (Northumbria University). Petrographic analysis will be carried out before and after hydrogen microbial interaction experiments to determine if any mineralogical changes to the reservoir (e.g., mineral dissolution or precipitation). If time permits, potential geological storage sites be looked at across the UK, onshore and offshore. Specifically looking into Permian and Triassic Salt deposits and saline aquifers and DOGF on the UKCS.