Comparison of Combustion and Gasification for Energy Recovery from Residual Woody Biomass

Abstract

More than half of global electrical and thermal energy is generated by fossil fuels, around 63% in 2019. This is one of the main causes of greenhouse gas (GHG) emissions, responsible for the increase of the atmospheric average temperature above the reference level. Combined heat and power (CHP) generation from biomass may contribute to increasing renewable energy generation and reducing GHGs emissions, pursuing the goals of the European Union green deal 2021. In the present study, CHP generation potentiality, efficiencies, and environmental impact are compared numerically by using Aspen Plus V8.8 software between the thermal treatment of combustion and gasification integrated with a gas turbine system of residual woody biomass. The gas turbine is powered by the exhausts of biomass combustion in the first configuration, and by the exhausts of syngas combustion in the second one. Modeling of cogeneration through biomass combustion and gasification is developed based on the available literature data, founding a good agreement with the experimental campaign. Wood combustion is more advantageous in terms of cogeneration efficiencies (around 40% higher), whereas gasification emits lower GHGs.