Biogas scrubbing, compression and storage: perspective and prospectus in Indian context

Biogas is a clean environment friendly fuel. Raw biogas contains about 55-65% methane (CH4), 30-45% carbon dioxide (CO2), traces of hydrogen sulfide (H2S) and fractions of water vapours. Presently, it can be used only at the place where it is produced. There is a great need to make biogas transportable. This can be done by compressing the gas in cylinders which is possible only after removing its CO2, H2S and water vapour components. Pilot level trials to compress the biogas have been carried out by a number of earlier investigators working on the subject. This paper reviews the efforts made to improve the quality of biogas by scrubbing CO2 and the results obtained. There is a lot of potential if biogas could be made viable as a transport vehicle fuel like CNG by compressing it and filling into cylinders after scrubbing and drying. Thus the need emerges for a unified approach for scrubbing, compressing and subsequent storage of biogas for wider applications.