Concept assessment of a marine carbon capture system for vessel regulatory lifetime extension

Anthropogenic Greenhouse gas emissions increase rapidly throughout years, forcing International Maritime Organization (IMO) to set strict targets on reducing emission in shipping. Carbon Capture (CC) could be one of the solutions within the decarbonization spectrum, given its potential for significant emission reduction. The shipping community is already exploring CC solutions through concept studies, joint development projects and pilot demonstrations. However, no clear window for CC inclusion in CII calculations has been provided by IMO, at the time this paper is written. The objective of this paper is to explore on a concept design level, the capacity of a CC system to improve the CII of a VLCC tanker vessel, to ensure regulatory compliance throughout her life expectancy. Newbuilt and conversion assessment is conducted, accounting for the vessel’s annual operating profile and the benefits of tight heat integration. To calculate the CC performance, a process model is developed of a conventional amine-based carbon capture system integrated to the ship machinery, with and without waste heat recovery (WHR) for CC heat supply. At design conditions all features of CCS and WHR components are determined. At operating conditions, estimates of pumping and compression requirements, reboiler duty and WHR production capacity are evaluated and accounted for in the total footprint of the ship. The results are annualized and compared to baseline no CCS conditions. The associated increase in fuel consumption due to CC use is estimated, along with the CC system’s capital and operational costs.