Storage of a mixture of natural gas and hydrogen in underground gas reservoirs

Abstract

In accordance with the document of the Ministry of Industry and Trade – Hydrogen Strategy of the Czech Republic, it can be expected that in the coming years, pressure will be exerted to inject hydrogen into the gas infrastructure, which is currently used mainly for natural gas. Injection of hydrogen into natural gas can have an effect not only on the transport and distribution system, but also on the storage of this mixture in underground reservoirs in CR. This article aims to describe the issue of storing a mixture of hydrogen and natural gas in underground reservoirs. In particular, the effect on the storage capacity and on the overall integrity of the reservoir, problems with the embrittlement of the metal parts of the probes, the effect on the rubber seal. The paper therefore describes not only the effects on the storage of a mixture of hydrogen and natural gas, but also on the devices that are located on surface technologies. The results of studies from foreign literature demonstrate that the addition of 10-15% by volume of hydrogen to natural gas will have a minimal effect on the operation of the underground reservoir. The storage of a mixture of hydrogen and natural gas in the Czech Republic is currently a much-discussed topic, also regarding the experience with the storage of town gas (which contained a high proportion of hydrogen) in the Lobodice aquifer type underground gas storage.