Characterization and Estimation of Power Generation Potentials Of Some Agricultural Wastes

Abstract

India is developing at an incredible rate. With development, there is an alarming increase in the demand for energy. But at the same time, we as a nation, have to economize on our energy costs to focus on human developmental needs. It is an undeniable fact that we have to strive for energy self-sufficiency to stay relevant in the modern times we live in. In such context, the idea of biomass energy becomes very important and relevant. With its inherent advantages of carbon neutrality and sustainability, biomass energy is the way forward for the nation and the world at large. Biomass energy has the potential and the promise of becoming the prime energy source. Though many forms of bioenergy are in focus of many research and development agencies/organizations, harnessing the biomass energy through combustion is the simplest method. In this project, we attempt to analyse and discuss the feasibility and sustainability of this method. We would have to dwell upon the challenges posed by this method and attempt to quell these in a scientific manner. Abundant land and water resources are the major enabler for adoption of biomass energy, as a principle. But in practice, technical variables such as calorific value, ash content, presence of sulphur, greenhouse gas emissions play a significant role in the actual adoption of biomass as a major source of energy. To study these, we have chosen wastes of six different agriculture based biomass species such as banana (Musa acuminate), coconut (Cocos nucifera), arecanut (Areca catechu), rice (Oryza sativa), wheat (Triticum aestivum) and palm (Borassus flabellifer). The samples were analysed by proximate and ultimate analyses, and further correlation was established through regression analysis. Proximate analysis showed that the coconut has the highest volatile matter content (i.e., 73 wt.%) and banana has the highest fixed carbon content (i.e., 20 wt.%) which indicated higher calorific values. The determination of calorific values validated the former results. Palm exhibited lowest ash content suggesting no ash related problems during combustion. Ultimate analysis performed on some of the selected species showed high carbon and hydrogen contents in the leaves of coconut and arecanut. Out of some selected biomass ashes tested for their fusion temperatures, rice has the lowest initial deformation temperature (i.e., 938 0C) which is substantially above the boiling temperature, suggesting that all the selected biomass samples can be used safely for combustion in boilers up to a temperature of 800 0C. The bulk density of rice husk has been found out to be the highest (i.e., 336.257 kg/m3), suggesting facilitation of higher amount of rice husk in the boiler and, economical transportation and handling. An attempt has been made to develop empirical formulae statistically using regression analysis to predict gross calorific value using proximate and ultimate analyses data. The land requirements for energy plantation with selected biomass species were computed and found that approximately 4931, 524, 1757, 814, 3043 and 1146 hectares of land for harvesting banana, coconut, arecanut, palm, wheat and rice biomass species for assuring a perpetual supply of electricity at the rate of 5475 MWh per year for a group of 10-12 villages consisting of about 2000 households. Further, from the calculations of fuel requirement it was observed that coal requirement can decrease from 4968.0 to 4289.1 t/year and 4968 to 4008.6 t/year with the increase in biomass content from 0 to 15 % in the briquettes of coal with rice husk and coal with palm leaf respectively which suggests that agricultural biomass wastes can be used in co-firing mode for generation of electricity by substituting a portion of coal.