Chemical inhibition of hydrogen-air explosions: Literature review, simulations and experiments

Abstract

This paper summarises the first results from the joint industry project (JIP) ‘Risk-reduction for hydrogen installations by partial suppression of explosions’ (HyRISE). The main objective of the project is to develop fundamental knowledge that can support the development of practical solutions for mitigating hydrogen explosions in congested and confined environments by means of active systems for chemical inhibition. The aim is not to extinguish the incipient flame, but rather to lower the reactivity of the fuel-air mixture prior to ignition, and thereby reduce the consequences of an accidental explosion to a tolerable level. The paper consists of three parts: a review of previous work on chemical inhibition of premixed hydrogen-air flames, simulations with the chemical kinetics software Cantera, and experiments conducted in a 20-litre explosion vessel. The results demonstrate that chemical inhibition can be effective for hydrogen-air mixtures. However, it remains to develop efficient inhibitors and practical systems that can be implemented in industrial facilities, with satisfactory performance over a wide range of hydrogen concentrations.