Enrichment of Biogas from Biodegradable Solid Waste-A Review

Due to rapid increase in population and explosive evolution of life standards, there is tremendous increase in solid waste generation in the last few decades. Furthermore, most of the countries are going to be industrialized; hence more amount of energy will be required in upcoming decades. Today's more than 85% of the world demanded energy is supplied by fossil fuels. Fossil fuels are finite source of energy and therefore it is necessary to find out other alternatives for energy generation. Improper management of solid waste (MSW, waste biomass, etc.) is responsible for climate change, water and soil and local air pollution. These wastes have a high value with respect to energy recovery. The energy generation from the biological waste materials has been identified as alternative to the fossil fuels due to it's dual benefit of resource generation and waste minimization. Anaerobic conversion of solid waste biomass is a matured technology for environmental protection and waste management. The end products are biogas (a mixture of methane and carbon dioxide), which is a useful, renewable energy source and organic manure slurry which can be used as fertilizer for agricultural purposes. Anaerobic digestion is a simple process, used to convert organic material (from a wide range of solid waste) into methane. This paper is mainly focused on the anaerobic digestion of solid waste biomass to produce methane, technologies related to pre-treatment of feed materials and post treatment of product gas to enrich the methane composition and the value addition of product fractions are also discussed.