The U.S. Maritime Administration (MARAD) has recently released a study that evaluates total fuel cycle emissions for natural gas versus conventional marine fuels. This study was conducted as a part of MARAD’s Maritime Environmental & Technology Assistance program, which focuses efforts on emerging marine transportation and environmental issues.
Results of the study showed that the use of natural gas as a propulsion fuel can reduce air quality pollutants and reduce major greenhouse gas emissions when compared to conventional fuels.
The study concludes that when taking into account the global warming potential of CH4, N2O, and CO2, LNG fuel is found in coastal scenarios (both West Coast and East Coast) to produce less overall GHG emissions (as measured in CO2 equivalent units) than diesel fuel scenarios using either low-sulfur distillate (depending upon pathway) or high-sulfur residual fuel.
While this analysis does not include an assessment of impacts resulting from each of those pollutants, one can consider the fact that the IMO deemed NOx and SOx both important enough pollutants to regulate.
The information provided by this study is important as marine transportation stakeholders evaluate the use of natural gas as a viable alternative propulsion fuel for reducing air polluting emissions.
The research was conducted through a cooperative partnership with the Maritime Administration, the University of Delaware and The Rochester Institute of Technology.
The complete study can be viewed here.