Alternative Fuels versus Traditional Fuels in Shipping

Abstract

The main source of emissions from sea-going vessels is the exhaust gas from burning fuel in the ship's combustion engines. The first regulation of exhaust gas emissions from ships, which came into effect twenty years ago, was not strict. However, the global 2020 cap on maximum 0.5 % sulphur in the exhaust gas from the ships combustion engines, in combination with the required reduction of nitrogen and carbon emissions for new-built vessels, is an economical and technical challenge for the shipping industry. Alternative fuels such as LNG, LPG, Methanol or Hydrogen is one tempting option for meeting these new requirements. Alternatively, traditional fuels can be used in combination with measures such as exhaust gas cleaning, engine and combustion process modifications. The data and literature of the options and their pros and cons tends to be fragmented and not easily available for shipping- lines, designers and builders. For these reasons, the motivation for this study has been to give an overview of options and compare based upon key performance indicators. The comparison includes; Emissions from Combustion; Well to wake emissions; Space and weight requirements; and Cost.