{"id":464,"date":"2023-03-03T06:40:00","date_gmt":"2023-03-03T05:40:00","guid":{"rendered":"https:\/\/www.geostockgroup.com\/un-dernier-article-pour-faire-la-demonstration-du-blog\/"},"modified":"2023-09-28T15:25:04","modified_gmt":"2023-09-28T13:25:04","slug":"four-ways-to-store-large-quantities-of-hydrogen","status":"publish","type":"post","link":"https:\/\/www.geostockgroup.com\/en\/four-ways-to-store-large-quantities-of-hydrogen\/","title":{"rendered":"Four ways to store large quantities of hydrogen"},"content":{"rendered":"\n
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Abstract<\/h3>\n

Hydrogen can be stored in underground caverns or geological structures in one of four ways.
\nThe easiest way to store hydrogen is in salt caverns. These are created by injecting fresh water or water with low salt content into a well down to a salt geological layer, with the extraction of salt-saturated brine. The caverns measure between 50 and 100 metres in diameter and up to several hundred meters tall where the salt formation is thick enough. Salt caverns are not lined, as the salt itself acts as a sealant. This type of storage is suitable for storing hydrogen at extremely high pressures where the salt layer is deep enough.
\nThe second way to store large quantities of hydrogen is to inject pure hydrogen or a hydrogen-methane mix into porous rock, in a depleted oil or gas field, or an aquifer. The hydrogen content may vary from a few per cent to 100 per cent. Reservoir and biochemical testing\/modelling are to be performed accordingly. The hydrogen-methane mix can be withdrawn and injected into the network. Alternatively, hydrogen can be separated from methane at the well head, for example using pressure swing adsorption technology.
\nHydrogen can also be stored underground by converting it into a liquid carrier, such as ammonia, which can then be stored in a Lined Rock Cavern. A liner is required to prevent contact between ammonia and water. The pressure and temperature are adapted to optimise the entire supply chain. The advantage of using ammonia is that proper storage conditions can be fulfilled without the need for excessive pressure or temperature.
\nLastly, hydrogen can be stored underground by directly injecting it into a Lined Rock Cavern. This may take the form of compressed storage (gaseous hydrogen) or cryogenic storage (liquid hydrogen), the choice once again depending on the supply chain as a whole. A liner is required owing to extremely high pressures and low temperatures. It should be noted that storing hydrogen in a Lined Rock Cavern involves a few technical difficulties that have yet to be resolved.
\nThese four underground hydrogen storage techniques differ in terms of their technology readiness level (TRL) and cost. All four will likely be required in the coming years to satisfy the needs of a booming market.<\/p>\n <\/div>\n <\/div>\n\n<\/section>\n\n\n\n

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Author<\/span><\/p>\n

Louis Londe,<\/strong> Technical Director, Projects & Innovation, Geostock<\/em><\/p>\n <\/div>\n <\/div>\n\n<\/section><\/div>\n\n\n\n

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Introduction<\/h3>\n

Hydrogen has been identified as an energy carrier that could play a major role in decarbonisation, and green hydrogen is seen as a possible substitute to fossil fuels. A number of governments and institutions have announced ambitious plans for developing a hydrogen economy, with the European Community having set a 2030 target of 40 GW of electrolysers producing 10 million tonnes of renewable hydrogen (European Commission, 2020). Similar plans exist in other world regions.
\nThese substantial quantities of hydrogen will require storage capacities. Whether these storage capacities will be scattered or centralized remains an open question, but many analysts consider that large and centralised storage units will be needed.
\nUnderground storage is likely to be the best solution for fulfilling extensive storage needs (Jens, 2021) as it boasts numerous advantages in terms of environment protection, safety and, above all, CAPEX (for high storage capacity) and OPEX.
\nThe various methods for the underground storage of hydrogen are described below, from the easiest to the most challenging.<\/p>\n <\/div>\n <\/div>\n\n<\/section>\n\n\n

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Hydrogen storage in salt caverns<\/h3>\n

Salt caverns are a proven technology for storing hydrocarbons (Londe, 2017), including natural gas, liquid hydrocarbons such as crude oil or refined products, and liquefied hydrocarbons such as LPG. More than 1,900 salt caverns exist worldwide.<\/p>\n

Salt caverns are created by solution mining, i.e. by injecting fresh water or sea water into a deep well. Creating a volume of one requires the injection of eight to ten volumes of water. Solution mining is also referred to as the \u201cleaching\u201d process. In direct leaching, fresh water is injected through a central tubing and saturated brine is withdrawn through the annular space. Reverse leaching consists in injecting fresh water into the annular space and withdrawing saturated brine through the central tubing. Cavern shape is controlled by positioning the tubing, adapting the water flow rate and selecting direct leaching or reverse leaching. Cavern dimensions are to be adapted to the requirements of the owner and the characteristics of the salt layer. Cavern heights greater than 300 metres are common practice, while cavern diameters are generally between 50 and 100 m. A large variety of sizes exist, ranging from 50,000 m3<\/sup> to more than 1,000,000 m3<\/sup>. Creating a 500,000 m3<\/sup> salt cavern takes between six months and two years.<\/p>\n <\/div>\n <\/div>\n\n<\/section>\n\n\n

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The operating pressure depends on cavern depth. If the cavern is deep enough, say more than 1,000 m deep, operating pressure can exceed 200 bar. A minimum pressure is required to prevent salt damage and cavern closure by excessive visco-plastic behaviour (referred to as \u201csalt creep\u201d). The gas inventory at minimum pressure is the \u201ccushion gas\u201d, which represents approximately one third of the total gas.<\/p>\n

Salt caverns were first used for hydrogen storage five decades ago in the UK, the first such cavern being commissioned near Teesside in 1972. Three caverns have been built on this site for a total amount of approximately 2 Mm3<\/sup>, at a depth of 400 metres, with an operating pressure of around 50 bar (Lindblom, 1985).<\/p>\n

Since then, only six salt caverns have been built for hydrogen storage, all of them in the USA (Moss Bluff, Clemens Dome, Spindletop) and in the UK (Teesside). These hydrogen storage facilities are all devoted to the chemical or petrochemical industry, the hydrogen molecule being used for its chemical properties. The current trend is to use hydrogen for its high energy density, with various salt cavern projects having been launched recently to store hydrogen as an energy carrier. There is obviously no technical showstopper to create salt caverns for hydrogen. Indeed, existing hydrogen caverns demonstrate:<\/p>\n