Techno-economic and environmental impact assessment of chemical absorption based shipboard carbon capture and storage

Shipboard carbon capture and storage (SCCS) is a viable retrofit for maritime decarbonisation, yet its environmental and techno-economic performance remains under-quantified. This study links life-cycle assessment with life-cycle costing to evaluate SCCS across four fuel configurations comprising very low sulphur fuel oil (VLSFO), marine gas oil (MGO), liquefied natural gas (LNG), and methanol, analysed with/without capture. Fuel system boundaries follow International Maritime Organization guidance. The SCCS boundary covers post-combustion monoethanolamine (MEA) absorption, compression/liquefaction and onboard liquid CO 2 storage; one-off manufacture/transport/installation and periodic maintenance are included, whereas port offloading and downstream transport, storage or utilisation are excluded. To enhance generalisability, conservative settings are adopted, assuming post-combustion monoethanolamine at 1.5 kg/t CO 2 , 58% capture efficiency, 3.7 GJ/t CO 2 energy use, and a 30-year service life with 5-year maintenance. Under these settings, installing SCCS lowers well-to-propeller greenhouse-gas emissions by 48.8–49.5% across all fuels after including 8.5–9.2% SCCS self-emissions. These net reductions support technical feasibility through policy alignment, with attained Energy Efficiency Existing Ship Index decreasing and Carbon Intensity Indicator improving by up to two grades for representative container, bulk-carrier, and tanker vessels. MGO with SCCS attains decarbonisation comparable to methanol, hence the economic comparison focuses on these two pathways. Over 30 years, MGO with SCCS is 7.1% less costly, with fuel prices the primary driver. Probabilistic analysis indicates SCCS on MGO is the lower-cost option in 69.8% of cases. Overall, within the stated boundary, the findings demonstrate the significance and effectiveness of SCCS for ship decarbonisation. • Study links life cycle assessment and costing for ship carbon capture and storage. • Shipboard carbon capture cuts well-to-propeller emissions by 48.7% to 49.5%. • Carbon capture on ships helps meet 2030 International Maritime Organization rules. • Marine gas oil with carbon capture costs 7.4% less than that of methanol conversion. • Shipboard carbon capture is the lower-cost option in 81.7% of cases studied.