Integrated dynamic, regulatory, and economic assessment of onboard carbon capture systems

The decarbonization of maritime transport is a key objective of IMO greenhouse gas strategy, requiring reductions in CO 2 emissions. Carbon Capture Systems (CCS) offer a promising onboard mitigation solution; however, most existing assessments rely on steady-state assumptions and fail to capture ship operations variability. Also, Carbon Intensity Indicator (CII) evaluation methods do not fully reflect operational impact of CCS, including changes in net emissions and transport capacity. To address this gap, this study develops a novel integrated dynamic framework combining real operational data with physics-based models of engines and chemical absorption-based carbon capture. The framework simulates CCS performance under time-varying conditions, develops an enhanced CII evaluation method, and performs techno-economic analysis, including sensitivity analysis of key parameters. The framework was applied to a container ship emitting 63,547 tCO 2 annually, with 42.65 GWh of recoverable waste heat, evaluating four exhaust-integration scenarios and design capacities of 2–16 t/h. CO 2 avoidance increased from 19% at 2 t/h to 74% at 16 t/h when all engines were integrated, while fuel penalties increased from 2.2% to 15.5%. CCS reduced CII from 5.1 gCO 2 /t·nm (without CCS) to 1.44 gCO 2 /t·nm (16 t/h configuration), achieving A-ratings across all scenarios. Considering technical, regulatory, spatial, and economic performance, the integrated optimal configuration is 10 t/h, capturing from all exhaust sources, achieving 70.1% CO 2 avoidance, sustaining IMO A-rating compliance, displacing 242 TEU (1.62% of capacity), and a CO 2 avoidance cost of 171.5 $/tCO 2 . The results indicate that CCS delivers substantial emission reductions while maintaining regulatory compliance and economic and spatial feasibility.