Biogas as the promising natural resource and a competent substitute to petroleum resources: A few case studies

Biogas technology is centuries old. However, optimum and efficient utilization of biogas as a rich natural resource and as a close competitor to petroleum reserves is yet to catch sufficient momentum. The different advances and the prospects of biogas technology are discussed in this paper, with special emphasis to the following aspects: Use of multiple substrates (sewage sludge, waste paper and algal mass) other than cow dung for biogas production; Process of enrichment of biogas and design of the absorption – desorption system with aqueous MEA solution as the absorbent (including process optimization and software development); desulfurization of biogas (removal of H2S ) by a novel biochemical pathway; Utilization of enriched biogas (almost pure methane), for power generation (in thermal power plants); for production of synthesis gas and a myriad of chemicals from the same including hydrogen gas, methanol, nitrogenous fertilizers; synthesis of liquid fuels (based on Fischer – Tropsch synthesis); for use as an automobile fuel in place of CNG, LNG; manufacture of phosphate – rich biofertilizer (PROM) from the anaerobic digester sludge (discharged from biogas digester) and its utilization as an excellent substitute to synthetic phosphatic fertilizers (DAP, SSP and TSP).