Process development and techno-economic evaluation of methanol production by direct CO₂ hydrogenation using solar-thermal energy

This study proposes and analyzes a novel methanol production process developed by integrating CO₂ hydrogenation and thermochemical splitting technologies. Using Sunshine-to-Petrol, which produces liquid hydrocarbons using solar thermal energy, as the baseline framework, we developed a highly energy-efficient methanol production process comprised of the solar field for CO₂ and H₂O splitting using concentrated solar thermal energy, integrated with methanol production through the direct hydrogenation of CO₂ and CO. The optimal process configuration and operating conditions for maximizing the amount of methanol were established using a sequential quadratic programming. Consequently, the proposed process achieved a high energy efficiency of 15.5%, and the minimum selling price of methanol was established as 0.94 $/kg, accompanied by a 26% improvement over previous schemes and other CO₂-to-methanol frameworks. Furthermore, we examined additional alternative scenarios to establish the optimistic conditions such that the minimum selling price of 0.53 $/kg is considered as a competitive price in the methanol market.