Recent Development in Physical, Chemical, Biological and Hybrid Biogas Upgradation Techniques

Energy driven technologies and enhanced per-capita waste production have led to the establishment of novel technologies to simultaneously produce fuels as well as treat the wastes. Anaerobic digestion is cost-effective and sustainable process to produce biogas. Biogas is a mixture of CO2, CH4, H2S, is an eco-friendly and inexpensive renewable biofuel. This mixture of gases restricts biogas utilization in vehicular fuel, CHPs, therefore, biogas upgradation becomes a necessary step. Conventional upgradation technologies for example water scrubbing, physical adsorption, chemical adsorption, amine scrubbing, etc. are cost intensive and require high maintenance. Novel technologies like biological methods of biogas upgradation are being investigated and new improvements are made in the conventional methods. This review aims to give a close insight about various technologies of upgradation including, pressure swing, amine scrubbing, membrane separation, cryogenic separation, biological methods, etc., along with the major challenges and limitations. The study also intends to provide an overview about the future perspective and scope of these technologies.