CO2-emissions reduction potential of LNG compared with conventional fossil fuels and the influence of port manoeuvres

This is the authors' abstract. We don't add key points for this paper.

This study evaluated the CO 2 -emission reduction potential of liquefied natural gas (LNG) in maritime transport and examined the influence of vessel operational profiles on emissions performance. A roll-on/roll-off passenger case study indicated an estimated 17.07% reduction in CO 2 emissions using LNG relative to conventional-fuel use, which was lower than the 25%–30% reduction reported previously. To investigate this discrepancy, eight tanker vessels covering a combined distance of more than 1.77 million nautical miles were analysed. The results indicated an estimated CO 2 -emission reduction of ∼ 25% using LNG during long-distance operations, whereas frequent port calls, manoeuvring and auxiliary-engine use substantially reduced the estimated emission-reduction benefit. Additionally, annual distance sailed and CO 2 emissions were analysed for each vessel, yielding average emission rates of 0.196 t CO 2 /mile for coastal vessels and 0.499 t CO 2 /mile for Suezmax vessels. These findings indicate that operational factors play an important role in decarbonisation outcomes and highlight the need to combine fuel-transition policies with operational and port-based measures.