Deployment of integrated Power-to-X and CO2 utilization systems: Techno-economic assessment of synthetic natural gas and methanol cases

Abstract

Achieving the climate neutrality requires decisive actions in curbing CO2 emissions. Various possible strategies can be exploited for this target such as boosting renewable sources, increasing energy efficiency for both conversion and utilisation steps, deploying Carbon Capture, Utilization and Storage (CCUS) applications. Power-to-X (P2X) and CO2 utilization technologies got significant attention as options to reduce fossil CO2 emissions and produce sustainable chemicals. This work assesses large-scale synthetic natural gas (SNG) and methanol production from renewable H2 and captured CO2 from a techno-economic perspective. Sizes of investigated systems are 500 MWth for the SNG case and 100000 t/y for the methanol case to be relevant from an industrial perspective. The assessed concepts were modelled and simulated in a thermally integrated design for optimization of the overall energy utilization. The key performance indicators were calculated based on overall mass & energy balances. As results show, the SNG and methanol production systems from green H2 and captured CO2 have high energy efficiency (e.g., about 54–58 %) and very high CO2 conversion yields (about 96–99 %). From an economic point of view, these solutions are not yet competitive to existing fossil-based systems (e.g., production costs are about 16 €/GJ for SNG and about 755 €/t for renewable methanol compared to average 10 €/GJ for natural gas and 450–500 €/t for fossil methanol).