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A concise review of materials for solid-state hydrogen storage
The development of sustainable hydrogen production systems can have a great impact on transitioning from petrochemical and chemical industries to less carbon-intensive operations . However , one of the difficulties with using hydrogen on a large scale is storage . This article aims to provide a review of common hydrogen storage methods , with a specific focus on materials used for the solid-state storage method .
By Ali R . Al Shehhi a , Ibrahim M . Gadala b and Mohamed S . Gadala c
Hydrogen storage types
Typically , there are three methods that can be adopted to store hydrogen : gas-phase ( compressed ), liquid-phase , and solid-state . Figure 1 visually compares the operating temperature and corresponding energy to release the stored hydrogen for each method , with the thermochemical splitting of water as a reference point . 1
Gas-phase storage Storing hydrogen as a gas is a simple and common approach achieved through compression . Hydrogen is commonly stored in cylinders holding pressure up to 20 MPa . 2 In large-scale operations , storing hydrogen via compressed gas may require a high pressure of up to 35 – 70 MPa ( 5,000 – 10,000 psi ) and large tanks . Compression technology is considered volumetrically and gravimetrically inefficient . 3 Thus , the compressed hydrogen approach is not economically feasible due to factors such as high cost , relatively larger space requirements , and the safety of systems operating at such high pressures . Although gas storage is a mature technology with high efficiency , the low density of hydrogen limits its deployment at a large scale . 2 , 4
Fig . 1 . Hydrogen storage technologies , their operating temperatures , and their corresponding energy to release stored hydrogen 1
Hydrogen Tech World | Issue 8 | February 2023 39