Low-carbon emission electricity and methanol co-generation using thermochemical hydrogen production; thermo-environ-economic evaluation and AI-aided tri-criteria optimization

This study presents the development and optimization of a low-carbon integrated co-generation system for simultaneous electricity and methanol production. The proposed configuration combines biomass gasification, an external fired gas turbine, a Vanadium-Chlorine (V–Cl) thermochemical water-splitting cycle, a steam Rankine cycle, and an integrated methanol synthesis unit. Unlike conventional methanol production pathways that rely on electricity-intensive electrolysis, the present system utilizes waste heat from the power cycle for hydrogen production, and internal CO 2 capture, thereby enhancing thermal integration and reducing CO 2 emission to atmosphere. A comprehensive thermo-environ-economic evaluation is performed to assess the system performance, and an AI-aided tri-criteria optimization is applied to find the best operating conditions. Results of parametric analysis indicate significant trade-offs between power production and methanol yield; for example, increasing the thermochemical system's input temperature difference raises methanol production, while reducing net power output. Compared with a conventional mono-power configuration, the integrated system reduces the CO 2 emission index by 24.4%, while results in a higher levelized product cost of ( L C O P ) reflecting the additional costs associated with the chemical production units. The TOPSIS-selected solution yields an L C O P of 63.63 $/MWh, which is 39.2% lower than the thermodynamic-based optimum, while maintaining an exergy efficiency of 38.49% and a CO 2 emission index of 0.572 kg/kWh. Overall, the proposed system demonstrates that integrating power generation with methanol synthesis can significantly improve carbon performance and enable more sustainable biomass utilization.