Sorbents for hydrogen sulfide capture from biogas at low temperature: a review

Biogas, e.g., biomethane, is produced by fermentation of organic matter and can be used as an alternative fuel or as a raw material for the production of hydrogen and syngas. However, biogas includes hydrogen sulfide (H2S) as a byproduct of fermentation. Hydrogen sulfide is toxic, has a foul odor, corrodes equipments, and deactivates catalysts. Thus, hydrogen sulfide has to be removed before biogas combustion or conversion. Compared with classical wet desulfurization, low-temperature dry desulfurization is of interest due to higher desulfurization, simpler operation, less pollution, and less energy consumption. Here, we review solid sorbents for low-temperature biogas desulfurization, such as activated carbon, metal-exchanged zeolites, single metal oxides, composite metal oxides, ordered mesoporous silica, and metal-organic frameworks.