Maximizing the potentials of biogas through upgrading

Biogas unlike fossil fuel is a renewable energy source. It is environment friendly fuel and can be generated in every part of the globe where lives exist. Biogas from digester plants contains about 55-65% methane, 30-45% carbon (iv) oxide, traces of hydrogen sulphide and fractions of water vapour. Efforts have been made by a number of investigators to improve the quality of biogas by removal of the contaminants through upgrading. This paper reviews various attempts at methane enrichment of biogas, results obtained and the cost implications. There is a lot of potentials in terms of increased energy per unit volume, wobbe index, wider application and ease of handling if biogas is upgraded to >95% CH4. Water scrubbing is cheap and simple. Although upgrading system may be incorporated in a family size plants, it appears that enrichment and compression requirement may only be economically feasible with large plants.