Development and comparative eco-techno-economic analysis of two carbon capture and utilization pathways for polyethylene production

The aim of this work is the design and eco-techno-economic analysis of novel technologies for low- and high-density polyethylene production, based on CO 2 capture and utilization in the methanol-to-olefins process. Two primary routes for methanol production are investigated and compared to the conventional method: direct hydrogenation of CO 2 to methanol and tri-reforming of methane and CO 2 . The former involves the conversion of CO 2 into methanol, while the second, natural gas and CO 2 are reformed to produce methanol. Methanol is converted into ethylene which is then polymerized into polyethylene. Utilizing simulation and lifecycle assessment results, we conducted comprehensive eco-techno-economic assessments for both polymers to assess the potential contribution of these pathways to a more circular economy. The results showed that a minimum selling price of at least 5,934 USD/tonne of polymer is needed to make the processes financially attractive. Since these prices are significantly higher than market prices, they are unable to compete in the market. Consequently, the impact of CO 2 utilization credit, as a financial incentive to encourage the adoption of technologies that reduce CO 2 emissions, is also studied. The analysis revealed that a minimum credit of 668 USD/tonne of CO 2 is needed to make the process economically viable. Moreover, our e-TEA results showed that the TRM-based route is more financially viable than the CO 2 hydrogenation alternative, provided that the CO 2 mitigation credit is lower than 468 USD/tonne of CO 2 . The sensitivity analysis of various parameters is also conducted to determine the profitability of each technology at various market conditions. • CCU is used for the production of LDPE and HDPE via the intermediate methanol • TRM is used as a comparative pathway for polyethylene production • e-TEA is conducted to compare the selling price of polyethylene to market price • Electricity and equipment costs have the largest contribution to selling price • A CO 2 credit of at least 668 USD/tonne CO 2 is needed to reduce the price gap