CO2 utilization for methanol production; Optimal pathways with minimum GHG reduction cost

Mitigating CO2 emissions from industries and other sectors of our economy is a critical component of building a sustainable economy. This paper investigates two different methanol synthesis routes based on CO2 utilization (CO2 capture and utilization [CCU], and tri-reforming of methane [TRM]), and compares the results with the conventional methanol production using natural gas as the feedstock (NG-MeOH). A comprehensive techno-economic analysis (TEA) model that includes the findings of the life cycle assessment (LCA) models of methanol production using various CO2 utilization pathways is conducted. Economic analysis is conducted by developing a cost model that is connected to the simulation models for each production route. Compared to the conventional process (with a GHG emission of 0.6 kg CO2/kg MeOH), the lifecycle GHG reduction of 1.75 and 0.41 kg CO2/kg MeOH are achievable in the CCU and TRM pathways, respectively. Furthermore, the results indicate that, under current market conditions and hydrogen production costs, methanol production via CO2 hydrogenation will result in a cost approximately three times higher than that of the conventional process. The integrated TEA-LCA model shows that this increased cost of production equates to a required life cycle GHG reduction credit of $279 to $422 per tonne of CO2 utilized, depending on construction material and selected pathway. Additionally, when compared to the CO2 hydrogenation route, the tri-reforming process (TRM-MeOH) can result in a 42% cost savings. Furthermore, a minimum financial support of $56 per tonne utilized CO2 will be required to make the TRM-MeOH process economically viable.

Automated summary

Mitigating CO2 emissions from industries and other sectors of our economy is crucial for building a sustainable economy. This paper investigates different methanol synthesis routes based on CO2 utilization and compares them with the conventional methanol production using natural gas. The results show that using CO2 capture and utilization and tri-reforming of methane pathways can significantly reduce greenhouse gas emissions. However, the cost of methanol production via CO2 hydrogenation is three times higher than the conventional process. The tri-reforming process can be a more cost-effective option, but still requires financial support.