To combat climate change, companies worldwide have been working on integrating hydrogen (H2) into the global energy mix as a fuel source. H2 has been around for decades; however, it was not used as an energy source but for applications such as desulfurizing diesel fuel in refineries. Now, H2 is seen as a valuable energy source for a sustainable future. To that end, infrastructure must be put in place to generate, store and transport H2.
Transporting and storing H2 comes with specifically unique challenges. The unique composition of H2, such as its low energy density, presents safety and financial concerns. The specific problems involved depend on the H2 form.
Transportation. The forms of H2 that can be transported are compressed and cryogenic liquid H2; however, it can also be transported using a carrier like ammonia or a liquid organic hydrogen carrier (LOHC), such as toluene and di-benzyl toluene. The options for H2 transportation are by pipeline, truck, ship and rail. Compressed H2 can be transported by pipeline truck or ship; cryogenic liquid H2 can be transported by ship and truck, while all four methods can transport ammonia (NH3) and LOHCs. When using a carrier, the process to produce H2 from the carrier must be low in cost and energy, in which NH3 is seen as the most feasible option.
According to the DNV’s “Hydrogen Forecast to 2050”, compressed gaseous H2 is the most cost-effective method of transporting large volumes over long distances.1 Small volumes are most cost-effectively transported by truck.
Liquid H2 presents distinctive challenges due to its higher energy density. In the event of a leak, compressed H2 will evaporate while liquid H2 may remain on the ground for a prolonged period. This can be a safety hazard when transporting or storing liquid H2.
Storage. According to the International Energy Agency, global H2 demand is forecast to reach 180 MMt by 2030, with nearly half of that demand coming from new applications, particularly in heavy industry, power generation and the production of H2-based fuels.2 Technology capable of storing H2 will be needed to meet this demand.
There are several methods to store H2, such as subsurface gas storage, compressed H2 tanks, pipeline infrastructure, liquid H2 tanks, NH3 tanks and liquid hydrocarbon tanks. Compressed H2 can be stored in pipeline infrastructure, compressed H2 tanks or subsurface gas storage. Cryogenic liquid H2 must be kept in liquid H2 tanks, NH3 in NH3 tanks (at around -33°C at bar 1) and LOHC in liquid hydrocarbon tanks. The stored H2 can then be used for industrial applications or to power fuel cells.
Various storing options must be considered when planning for demand. DNV developed a list of H2 storage options and associated considerations.1 The options are broken down into the energy storage type:
Several companies are developing H2 storage facilities to meet the future global market demand, primarily in conjunction with full-scale H2 hubs. A few notable pilot facilities are:
HYBRIT. HYBRIT is a pilot facility to store green H2 in a rock cavern in Luleå, Sweden. This facility was developed by SSAB, LKAB and Vattenfall and has been operational since September 2022. The facility is now in a two-year testing phase. The partners aim to contribute to the decarbonization of the steel industry.
ACES Delta. ACES Delta is a joint venture (JV) between Mitsubishi Power Americas and Magnum Development. The JV was formed to create a renewable energy hub to produce, store and transport green H2. The hub will produce 100 metric tpd of green H2 and can store up to 300-gigawatt hours of energy. The hub will be in Utah, U.S.
KRUH2. Uniper received funding for the planned H2 pilot project at the Krummhörn natural gas storage site in Krummhörn, Germany. The facility has not been commercially used since 2017, and Uniper intends to test H2 storage on an industrial scale. The plant commissioning is planned for 2024, with a storage capacity of up to 250,000 m3 of H2.H2T
LITERATURE CITED
1 DNV, “Hydrogen Forecast to 2050,” June 2022, online: https://www.dnv.com/Publications/hydrogen-forecast-226443
2 International Energy Agency, “Hydrogen,” September 2022, online: iea.org/reports/hydrogen