Utilization of Waste Biomass into Useful Forms of Energy

Abstract

The rising cost of fossil fuel and environmental concern has motivated the scientific committee to research on alternative sustainable solution for energy and economic development. One of such sustainable energy resource is biomass, which is abundant, clean and carbon neutral. Agricultural residue which is abundant and causing problems of storage being wasted without using in any form energy source. The present study highlights utilization of residue biomass to useful form of energy using different thermochemical conversion technologies. This study is presented as a technical review cum analysis study which has been done on various common agricultural wastes for their Thermochemical conversion technologies which includes combustion, gasification, pyrolysis, torrefaction and liquefaction. The common agricultural wastes that are being taken for study are coconut shell, rice husk, corn cobs, cotton stalk, groundnut shell, cotton, sugarcane (bagasse). In Combustion process, the yield of gaseous product is around 50%, which can be utilized for combined heat and power production. In the combustion process, drawbacks are discussed and specified. It was observed that suitable combustor can be implemented for improving its oxidative characteristics so that the product gas yield can be increased for high quality steam production. In Gasification process, the biomass is partially oxidized to give a raw product gas or syngas which can be used in IC engines and for running gas turbines to produce electricity. It was observed that product gas or syngas obtained is around 85–90% pure compared to the gases obtained from coal gasification. Suggestions are made to improve the yield of syngas by suitable designs for specially downdraft gasifiers. Finally, Pyrolysis process of biomass is discussed, and focuses on improving the yield of liquid content by varying the operating conditions. Bio-oil production from pyrolysis can be varied from 65 to 75% by varying operating temperatures (500–650 °C) and heating rate. Finally, in this study we suggest the design of pyrolyser with different operating conditions for maximum yield of liquid, an attempt was made to increase the liquid product and reduce the char/gas content.