Water Electrolysis in the Power-to-Gas Process

Abstract

As the world moves towards a carbon-neutral energy society, electricity networks will also have to undergo some innovation. As a revolutionary technology that can produce a range of gases to promote industrial development while maximizing environmental protection, power-to-gas (PtG) technology has been the subject of extensive discussion in recent years and will have a huge impact on the electricity grid of the future. In this review, three ways of producing hydrogen by electrolysis in the PtG process are comprehensively highlighted and discussed: alkaline electrolysis, proton exchange membrane electrolysis, and solid oxide electrolysis. Along with some of the limitations in practical implementations, the guiding concepts for the three approaches are presented. Their advantages and disadvantages are also summarized and compared. Some latest progress and breakthroughs are also collected and discussed in this review. Moreover, analysis about the economics and industrial applications as well as the present limitations and future outlook are also involved in the discussion part. It is hoped that this review study would increase interest in bridging technological gaps to realize scalable hydrogen production in the PtG method.