Strategies for introducing methanol as an alternative fuel for shipping

Although waterborne transport is an energy efficient means of transport, its contribution to greenhouse gas emissions is growing and pollutant emissions are high relative to other forms of transport. Emission legislation on the other hand is catching up by introducing strongly reduced emission limits in the upcoming years, which leads to an urgent need for alternative ways of fueling waterborne transport. In the Horizon 2020 “LeanShips” project, the use of methanol as an alternative fuel for shipping is studied in one of its demonstrators. In the demonstrator, a high speed marine diesel engine is converted for methanol use. This paper discusses the rationale for methanol as an alternative fuel for marine transportation, different possible strategies for operating vessel engines on methanol, their pros and cons, and the approach taken within LeanShips, namely dual fuel operation with methanol port injection. The potential of methanol concerning energy efficiency and pollutant emissions is discussed, as well as other demonstration projects on methanol and next steps for methanol engine developments