Environmental feasibility of biogas and biodiesel as fuel for passenger ferries

Övrigt konferensbidrag, 2011

Mobility is important in our everyday life. Marine transportation has the potential to increase its level of sustainability, by implementing new cleaning technologies, increase its energy efficiency and/or by changing fuel. The ferry traffic between the Swedish mainland and the island Gotland has a unique opportunity to be a first mover with environmentally sustainable shipping solutions, as it is procured by the Swedish authority Rikstrafiken. The present contract expires in January 2015 and Rikstrafiken has therefore made an investigation regarding the future ferry traffic [1]. This investigation stresses long term economical, social and environmental sustainability as conditions for the future ferry traffic. One possible solution to come closer to environmental sustainability could be to use biogas as fuel. Biogas has shown good life cycle environmental performance as vehicle fuel (e.g.[2]), but the use of liquefied biogas on ships has not been tested or evaluated. Liquefaction is needed in order to have acceptable energy content per unit volume of the fuel, but the liquefaction process is energy intensive and costly [3]. Biodiesel is another possible solution to consider. Both biogas and biodiesel can be blended with fossil fuels (natural gas and diesel, respectively) [4]. Here the environmental performance of liquefied biogas and biodiesel are compared with marine gas oil and liquefied natural gas.