Upgrading of Biogas to Biomethane

In a decentralised energy supply with renewable resources, the use of biogas from anaerobic digestion, gains importance due to the high content of methane and the wide range of applications. The biogas contains 50 - 55 per cent of methane, 40 - 45 per cent of carbon dioxide and hydrogen sulfide in traces. Currently, biogas is mainly applied in small to medium scale heat and power production. However, the high carbon dioxide content reduces the fuel calorific value and in turn, limits the engine peak power.The traces of hydrogen sulfide produces sulfuric acid, which corrodes the internals of pipes, fittings etc. Therefore, instead of combusting the biogas directly, removing carbon dioxide and hydrogen sulfide contents, and using the biomethane (from biogas) for combustion has been an attractive fuel for IC engines, for power generation, as well as thermal application.