Biomass Gasification for Clean Methanol Synthesis: A 4E-Based Model for Circular Carbon Economy and Green Energy Transition

The increasing reliance on fossil fuels has intensified carbon dioxide emissions, highlighting the need for cleaner and more sustainable fuel production pathways. In this study, a renewable methanol production system based on biomass gasification, carbon dioxide utilization, and renewable hydrogen integration is proposed and systematically evaluated. The process is modeled using Aspen Plus and assessed through a comprehensive 4E framework, including energy, exergy, economic, and environmental analyses. The results indicate that the proposed system achieves a methanol production cost of 428.28 $/t, an overall exergy efficiency of 20.89%, and a net power requirement of 13.45 MW, while the total environmental impact is limited to 0.1272 Pts/s. These findings demonstrate that eliminating energy-intensive units such as gas turbines and conventional post-combustion carbon capture can significantly reduce energy consumption, costs, and environmental burdens. Overall, the proposed configuration offers a technically feasible and environmentally favorable pathway for clean methanol production and contributes to sustainable fuel development and circular carbon utilization.