Biomethane is methane derived from biological sources and constitutes a sustainable energy carrier whose chemical composition is identical to natural gas. The biomethane industry is booming due to the on-going transformation of the energy system from fossil fuel-based to sustainable fuel-based. Up to 2020, investment of up to e12 billion is expected in the biomethane industry in Germany alone1. Biomethane is obtained after purifying biogas or landfill gas, which in turn is produced by the bacterial, anaerobic digestion (fermentation) of biomass. Biogas composition is shown in Table 1, and the biogas-treatment scheme is depicted in Figure 1. As Table 1 shows, sulphur mainly occurs as hydrogen sulphide (H2S) in biogas in concentrations from 100 to 30,000 ppm (0.01 – 3% v/v). The exact concentration depends on the substrate used during fermentation and on the process conditions prevalent in the fermenter.