Quantitative risk assessment of aqueous formate for hydrogen storage

In recent literature, aqueous formate/bicarbonate has been proposed as a safer alternative hydrogen storage system under normal operating conditions. In the present work, a preliminary quantitative risk assessment is presented for the first time on a standard tank for hydrogen storage containing aqueous formate mixture invested by an external fire. The results are compared to compressed hydrogen tanks at 350 bar as a benchmark. Frequency and consequence analysis were used to build risk maps. Results show that aqueous formate storage is intrinsically safer in the case of catastrophic failure of the vessel, due to the presence of water in the system as well as in the case of continuous release from safety valves, because of the lower operating pressure required in the storage vessel.