Bio-CO2 to e-Methanol: A Value Chain Assessment for Integration into the European Maritime Sector

e-Methanol produced from biogenic CO2 and renewable hydrogen has emerged as a promising carbon-neutral maritime fuel, offering a viable pathway to reduce the sector's reliance on fossil fuels and support large-scale decarbonisation. This study provides an assessment of critical aspects throughout the value chain, spanning biogenic CO2 sourcing and capture, renewable hydrogen production, methanol synthesis, logistics, and maritime end-use. Process models are developed in Aspen Plus™, including a benchmark CO2-MEA capture system and an alternative four-reactor methanol synthesis configuration with intermediate cooling and product separation. A sensitivity analysis of the CO2 capture process is first performed to evaluate the influence of feed characteristics and design parameters on capture efficiency. The four-reactor synthesis scheme is then assessed under varying CO2 purities (50-99 mol %), demonstrating strong suitability for inert-rich feeds. Finally, two port-level case studies for EU’s major bunkering hubs indicate that replacing 0.5-2% of the annual bunkering demands would require approximately 135-749 ktpa of biogenic CO2 and 19-103 ktpa of renewable hydrogen (144-800 MW of electrolyser capacity). Results showed that those demands are within the scales of existing port infrastructures, but coordinated development of CO2 supply, hydrogen production, and fuel logistics are critical to achieve across the value chain.