Energy Recovery Based on Gasification of Residues for Decarbonisation of the Agriculture Sector

Global energy demand is rapidly increasing, with about 80% still met by fossil fuels, contributing to resource depletion and climate change. As a renewable alternative, agricultural biomass waste, specifically olive kernels (OK) and olive tree cuttings (OTC), appears to be promising for clean energy production. This study proposes a numerical model in Aspen Plus to simulate combined heat and power (CHP) generation via air gasification of OK and OTC. The gasification model is calibrated and validated by using experimental data available in the literature related to five different operating conditions, obtaining an average deviation of predicted syngas composition from experimental outcomes in the range of 1.23% to 13.26%. The developed model is then used to identify optimal gasification conditions, finding a temperature of 950°C for OK and 900°C for OTC at an equivalence ratio of at least 0.2. If globally available, OK and OTC were utilized this way in 2024, they could produce 20,375 MWh of electricity and 38,829 MWh of thermal energy, potentially cutting CO2 emissions by 16 Mt/yr compared to the use of conventional energy sources.