Hydrogen enriched LNG fuel for maritime applications – A life cycle study

Abstract

This study evaluates the engine performance and life-cycle emissions of hydrogen enriched LNG as a pragmatic solution to more rapidly introducing hydrogen as marine fuel, while waiting for pure hydrogen fuel infrastructure to be built. Engine experiments in a 4-stroke marine diesel engine operating with a spark-ignited pre-chamber ignition system were conducted, and a wide range of engine exhaust emissions measurements including CH4, N2O, H2, and particulate matter (black carbon emission evaluation) were recorded at varying engine loads. The fuel compositions ranged from pure LNG operation to pure hydrogen operation and also included pure conventional diesel fuel oil for comparison. The research methodology integrates engine tests with a full well-to-wake life-cycle assessment (LCA). The impact of using 39.6% hydrogen by energy fraction in natural gas reduced GHG emission by 37.8% on a life-cycle basis at 50% engine load, which could mean a significant reduction of GHG emissions.