Future fuel for worldwide tankershipping in spot market

Abstract: Ship exhausts contain high levels of sulphur oxides, nitrogen oxides, carbon dioxide and particles dueto the heavy fuel oil, HFO, used for combustion and the combustion characteristics of the engine.As a result of upcoming stricter regulations for shipping pollution, as well as growing attentionto greenhouse gas emissions, air pollution and uncertainty of future petroleum oil supply, a shifttowards a cleaner burning fuel is needed.This work explores potential alternative fuels, both conventional and unconventional, and abatementtechnologies, to be used by tankers in the worldwide spot market to comply with upcomingenvironmental regulations in the near and coming future. As a reference the product tanker M/TGotland Marieann is used and recommendations for which fuel that shall be used by the referenceship in 2015 and 2020 are presented.The environmental assessment and evaluation of the fuels are done from a life cycle perspective usingresults from Life Cycle Assessment, LCA, studies.This study illustrates that, of the various alternatives, methanol appears to be the best candidatefor long-term, widespread replacement of petroleum-based fuels within tanker shipping. It does notemit any sulphur oxides nor particles and the nitrogen oxides are shown to be lower than those ofmarine gas oil, MGO. The global warming potential of the natural gas produced methanol is notlower than that of MGO, but when gradually switching to bio-methanol the greenhouse gas emissionsare decreasing and with methanol the vision of a carbon free society can be reached.For 2015 a switch towards methanol is not seen as realistic. Further research and establishment ofregulations and distribution systems are needed, however there are indications that a shift will bepossible sometime between 2015 and 2020. For 2015 a shift towards MGO is suggested as it involveslow investment costs and there is no need for infrastructure changes. As MGO is more expensivethan methanol, a shift is preferable as soon as the market, technology and infrastructure are ready.