Biogas is produced from biological wastes such as landfills, industrial waste (cheese whey, slaughterhouse waste) and agricultural waste (manure, forest residues). Biogas contains CH4, it is a valuable energy source. If biogas is not recovered and burnt, CH4 is released to the atmosphere: 20 times worse than CO2 for green house effect. Although Biogas can be burnt as energy source, it contains H2S ...