Techno-economic analysis, energy, exergy and environmental assessment of green methanol production via solar-driven gasification of corn stalk using Aspen Plus simulation

This study proposes an integrated solar-driven corn-stalk gasification system for green methanol (MeOH) production and conducts a comprehensive 4-E analysis (energy, exergy, economic and environmental) using Aspen Plus. Concentrated solar heat with molten-salt thermal energy storage (TES) is used to meet the high-temperature demand of gasification, while alkaline water electrolysis supplies renewable hydrogen (H2) for MeOH synthesis, thereby forming a near-closed carbon cycle. Using Zibo, Shandong Province as the evaluation site, key parameters were set, including a gasification temperature of 900 °C and a steam-to-biomass ratio (S/B) of 0.4. Simulation results indicate that the total energy input of the system is 10504.32 kW. The mechanical energy output reaches 6512.67 kW, resulting in solar energy and exergy efficiencies of 55.7% and 53.2%, respectively. Techno-economic analysis (TEA) shows that, for an annual MeOH production of 4000 tons, the total system investment is estimated at 14.86 million euros. The levelized cost of MeOH (LCoM) is calculated at 960 €/t. Environmental assessment reveals a CO2 emission intensity of just 0.114 t/GJ, which is 22.1%–65.2% lower than conventional fossil fuel-based MeOH production pathways. Overall, the study demonstrates techno-economic feasibility for solar-integrated biomass gasification for green MeOH, enabling deep decarbonization in maritime transport.