Techno-economic analysis of onboard carbon capture for container ships under variable engine load

Decarbonising the naval shipping sector is of paramount importance to decrease global CO2 emissions. This work presents a techno-economic analysis of onboard solvent-based carbon capture for an ultra-large container ship, powered by two dual-fuel engines fed with either heavy fuel oil or liquefied natural gas. Variable load factor depending on the fuel used by the ship and on the chosen design to supply the necessary heat and electricity to the carbon capture unit and a novel configuration based on electric heat pump is investigated. The results highlight that onboard carbon capture determines an increase in fuel consumption with respect to the unabated ship, that varies depending on the exhaust gas CO2 content (hence, on the ship fuel) and on the selected process design. The integration of the electric heat pump leads to a significant decrease in this additional fuel consumption and better results in terms of CO2 avoidance and costs.