Middle Scale Hydrogen Sulphide Conversion and Valorisation Technologies: A Review

The growing energy demand, together with the depletion of sweet gas reservoirs, impose the monetization of ultra-sour natural gas fields with a high H2S content. To date, in large scale facilities, H2S is removed from natural gas through amine washing and it is converted to sulphur in the Claus process. The Claus process is the leading H2S conversion technology for large scale applications. Regarding small scale plants, scavengers are the most efficient and widely spread choice. On the other hand, present middle scale options show quite high operating costs. Therefore, research efforts are devoted to developing new intermediate scale alternatives with lower costs and easier operability. When developing a new process, the study of the state-of-the-art is the first essential step. No systematic review of H2S valorisation technologies is available in literature. To fill this gap, the aim of this work is to summarize the available processes considering both commercial and novel tendencies for H2S conversion. For each technology, details about process operating conditions are discussed and the typical application is provided, when possible, together with the corresponding pros and cons.