Negative Emission Power Plants Thermodynamic modeling Evaluation and Techno economic analysis of a biomass based integrated gasification solid oxide fuel cell gas turbine system for power heat and biochar Co production

Abstract

Negative Emission Power Plants (NEPPs) can deliver electrical power while simultaneously newlineremoving CO2 from the atmosphere. Bio-Energy with Carbon Capture and Storage (BECCS) is one newlineof the promising technologies used to develop NEPPs, which use biomass (organic matter such as newlinecrops or wood pellets) as fuel. The biomass absorbs CO2 from the atmosphere through photosynthesis during its growth and released to the atmosphere when it is burned in power plants. Hence, the biomass used as a fuel in the power plants is assumed to be carbon neutral. When the CO2 released by the power plants is captured and sequestered in geological reservoirs using Carbon Capture and Storage (CCS) unit, it results in the permanent removal of CO2 from the atmosphere. This kind of combination of biomass utilization in the power plant and the simultaneous removal of CO2 from the atmosphere is the basic principle of BECCS. The aim of this thesis research is to develop thermodynamic models of negative emission power plants based on Biomass-fed Integrated newlineGasification Fuel Cell system with Carbon Capture and Storage (BIGFC/CCS) system. These models are eventually used to carry out detailed exergy economic analysis in order to evaluate the technoeconomic viability of such systems and if possible, to come up with suggestions for economically viable process designs and operation strategies. The thermodynamic steady state model of the proposed system is developed using modelling software Cycle-Tempo. The influence of two gasification agents, namely, air and steam-oxygen on the proposed system is investigated. A sensitivity analysis is carried out to investigate system response to stepwise increases in biochar coproduction (up to 10% by weight). A comprehensive exergy analysis indicated significant efficiency improvement for the steam-oxygen gasification case. The results show that steam-oxygen gasification yields higher electrical exergy efficiency (48.3%) and combined heat and power (CHP) exergy efficiency (54.6%) with 10% biochar co-production.