Assessment of heat balance in the FSRU regasification cycle aligns with IMO’s decarbonisation strategy

In 2023, the International Maritime Organization revised its greenhouse gas strategy, striving to reduce annual emissions from international shipping by at least 70% by 2040. The Mediterranean Sea will become an emission control area for sulphur oxides and particulate matter from May 2025, and the EU will include shipping in its Emission Trading System from 2024. Liquid natural gas is expected to become a cleaner marine fuel, but it alone cannot meet emission reduction goals. The cryogenic carbon capture process can separate CO2 from exhaust gases, compress it, and store it in a liquid state with high density. This study aims to integrate an energy balance equation model to analyse the energy exchange in the regasification process and identify potential areas for improvement and targeted solutions to enhance performance and comply with IMO emission regulations. Based on a mathematical model, the energy balances are calculated and yield the following results: steam heater (26,999 kW), R-290 preheater (5,837 kW), trim heater (3,290 kW), R-290 evaporator (13,322 kW), and LNG vaporiser (23,118 kW). A report also determined that within a temperature range between -56.6℃ and 31℃ and a pressure range of greater than 5.2 bar (absolute) and less than 74 bar (absolute), the CO2 is in a liquid phase. Due to CO2 density which fluctuates in liquid at 1032 kg/m3 and in solid phase at 1562 kg/m3 the physical condition is compatible with the storage stage of capture emission.