A Review of Ship Energy Efficiency and Emission Reduction Technologies under the IMO's Decarbonization Framework

Abstract

This paper presents a systematic review of ship energy efficiency improvement and emission reduction technologies. Framed within the regulatory framework established by the IMO namely EEDI, EEXI, and CII the study analyzes ship energy consumption structures, emission characteristics, and compliance requirements. From a technical pathway perspective, the paper focuses on energy efficiency improvement measures (including hull form optimization, lightweight materials, propulsion system enhancements, and renewable energy integration) as well as emission reduction strategies (such as exhaust gas after-treatment, alternative fuels, and intelligent operational management). The findings indicate that the synergistic integration of multiple technologies combined with intelligent optimization can significantly reduce ship carbon intensity. Looking ahead, technological breakthroughs in zero-carbon fuels, carbon capture, and digital twins are essential to advancing the shipping industry toward its carbon neutrality goals.