Abstract
Multi-criteria decision analysis (MCDA) techniques are becoming increasingly popular in decision making for technology selection because of their ability to capture the multi-dimensionality of technologies. Biogas typically refers to an odourless gas produced by anaerobic digestion of biomass using microorganisms. Its production can occur naturally in marshes and landfills or more commonly, in specifically designed plants called biogas digesters under controlled conditions. For techno-economic efficiency of a biodigester, several factors such as cost of plant are taken into consideration. This paper examines various available technologies for biogas digesters using defined selection criteria via MCDA and chooses the best alternatives at various scales of biogas production for a case study in South Africa with municipal biowaste as the target feedstock. 14 biogas plants were analysed in this study and the Puxin and Bio4gas digesters were the best alternatives for small and large scale biogas production respectively.