Simulation Study On Utilising Cold Energy Fuel To Liquefy Captured Co₂ On Lng-Fuelled Vessels

This study addresses the issues of abundant cold energy in fuel and the high energy consumption of CO₂ liquefaction capture by the shipboard carbon capture system in LNG-fuelled vessels. Two liquefied CO₂ schemes are proposed: an LNG cold energy and refrigeration cycle integrated CO₂ liquefaction system (Scheme 1) and an LNG cold energy and seawater diversion liquefied CO₂ system (Scheme 2). The two systems are simulated in Aspen HYSYS software and, based on the simulation data, multiple thermodynamic parameters of the system, including exergy efficiency, cold energy utilisation rate, and energy consumption, are calculated under different vessel operating conditions, thereby verifying the feasibility of the system. On this basis, the systems are optimised, enhancing their overall performance. Through a comparative analysis of the two schemes, Scheme 1 was selected to conduct an economic analysis of typical vessel routes and calculations were conducted to determine the reduction in energy consumption and the decrease in carbon emissions achieved by utilising LNG cold energy for CO₂ liquefaction and capture. The results prove that the system should have good practical applications.