Utilisation of Combined Absorption and Adsorption Method For the Purification of Biogas
Biogas is made up of methane of about 40-75%and Carbon dioxide of about 15-60%. It also contains some other
trace gases such as water, Hydrogen sulphide, siloxanes, hydrocarbons, ammonia, oxygen, carbon monoxide and nitrogen in
small amounts which varies with the types of biomass and production methods. In this study, the biogas generated is to be
used for the purpose of electricity and internal combustion engine fuel. Hence the biogas has to be purified before the use
inorder to achieve better results. This was achieved in combined absorption and adsorption method. The results showed that
the hydrogen sulphide concentration was initially 350 ppm and 375 ppm for two test which was then reduced to 15 ppm and
25 ppm respectively. This could be achieved with the help of activated carbon and absorbent nano material. The carbon
dioxide concentration which was 34% initially was reduced to 3% and 5% for the two test. With the help of silica gel the
maximum water concentration removal efficiency was achieved as 97%. Thus helps in improving the methane content to
42%.Hence the combined chemical process is proved to be a feasible system for biogas purification.
Keywords— Anaerobic digestion, Purification, Biogas, Absorption, Adsorption.