Acid gas, which contains toxic hydrogen sulfide, is produced
by
several sources, including refineries and processing plants for natural
gas. Catalytic decomposition and reforming of H2S offer
viable ways to produce hydrogen from a waste resource, with the added
benefit of reducing pollution. However, the conventional thermolysis
of hydrogen sulfide, including the traditional Claus process, is highly
endothermic and exhibits low conversion at low reaction temperatures.
While the photocatalytic pathway would offer a less energy-intensive
pathway, its overall efficiency regarding light/heat absorption and
utilization needs to be further enhanced. Hydrogen sulfide can be
converted via photothermocatalysis into elemental sulfur and hydrogen,
two value-added products. This process addresses the drawbacks of
pure photo and thermal procedures and could be a viable approach to
treating hydrogen sulfide waste streams. This study extensively examines
the potential interaction between photo- and thermocatalytic systems,
concentrating on the conversion of hydrogen sulfide to hydrogen. The
aim is to provide valuable insights and pathways for future optimization.
For the first time, as per the literature survey, a photothermocatalytic
process that could be extended to both hydrogen sulfide decomposition
and reformation toward hydrogen production is proposed, considering
current challenges and prospects.