ANNOUNCEMENTS
Access to affordable and clean energy Sustainable Development Goals 7 has a critical role to eradicate poverty Sustainable Development Goals 1, quality education Sustainable Development Goals 4, clean water and sanitation Sustainable Development Goals 6, decent work and economic growth Sustainable Development Goals 8, sustainable communities Sustainable Development Goals 11. Hence, providing access to reliable and affordable electricity to all has been the utmost priority of both developed and developing nations. Among other renewable energy sources, Biomass has a significant role in reducing global reliance on fossil fuels. This thesis examines biomass-based power generation's technical feasibility and financial viability through air-steam gasification technology.
The key findings of the experimental study on dual fired downdraft gasifier using air-steam as an oxidizing agent, its impact on gasifier, the performance of the internal combustion engines and financial benefits are presented in detail. An equivalence number was defined, a ratio of equivalence ratio to steam to biomass ratio. It is an important factor influencing the parameters of the gasifier performance. At equivalence number 1.8 to 2.5, the non–combustible fraction of the producer gas is reduced from 62% to 56 % (on a volume basis), a 10 % reduction in the non–combustible components. Higher heating value of 5.88 to 6.35 MJ. Nm-3 is observed when the H2/CO is in the range of 1.5 to 1.9. The theoretical specific fuel consumption obtained from gas produced at different equivalence numbers was analyzed, validated through the experimental results. It was found that specific fuel consumption is reduced from a baseline value of 1.2 kg kWh-1 to 0.95 kg kWh-1. The energy flow analysis revealed a cold gas efficiency of 86.29%. The biomass to electricity conversion efficiency is 21.6%. The de-rating of the internal combustion engine operated on hydrogen-enriched producer gas is reduced to 18%. Emission analysis reveals that CO emissions of 2.97 g. kWh-1 and NOX emissions of 1.07 g. kWh-1, when the Internal combustion engine is operated on hydrogen-rich producer gas.
The financial analysis of biomass gasifier-based power plants employing air and steam mixture as oxidising agents was carried out. The Levelized cost of power generation using air-steam gasification technology is estimated to be INR 7.68 per kWh, which is 7.12% less when compared to the cost of power generation through conventional air gasification (Rupees 7.68 per kWh). The payback period for air-steam gasification power plants was reduced to 4.64 years from 5.45 years (air gasification) which is a 17 % reduction. Therefore, biomass gasifier-based power plants using air-steam gasification are financially viable even when the PLF is less than 80%. The NPV of the air steam gasification power plants is as high as INR 29.34 million (@ IRR 23%); the same in the case of air gasification was INR 12.24 million (@IRR 17%). The adoption of air-steam as a gasification agent positively influences the cash flow statement of the power plants and reduces the viability gap funding burden.
The findings presented in this thesis directly relate to all sections of society; the outcomes have clear policy implications for India's governance of the renewable electricity sector.
