Energy, exergy, exergoeconomic, and environmental analysis of a new biomass-driven cogeneration system

Climate change, resource scarcity, and air and water pollution are the fatal results of mismanagement in fossil fuel utilization. Also, the lower energy efficiency of the conventional stand-alone energy conversion systems encourages researchers to substitute the traditional systems with sustainable combined heating and power (CHP) for improving their efficiency. Accordingly, a novel biomass-based heat and power cogeneration system, including a gasifier, a gas turbine, a Stirling engine, and a S-CO2 cycle coupled with a domestic water heater is proposed and analyzed from energy, exergy, exergoeconomic and environmental viewpoints. This study aims to evaluate the effect of using different biomass feedstocks (paper, wood, paddy husk, and municipal solid waste) in the gasifier on system performance. Also, the effect of integrating the Stirling engine with the stand-alone CHP system is studied. Moreover, a detailed parametric analysis is performed to assess the effect of varying operating parameters on system efficiency. According to the obtained results, using municipal solid waste as the input biomass result in the highest exergy efficiency by 41.36% and the lowest CO2 emission by 0.9021t/MWh. Also, the system with the Stirling engine has a higher exergy efficiency and lower CO2 emission rather than the system without the Stirling engine.