# Multicriteria Analysis of Alternative Marine Fuels in Sustainable Coastal Marine Traffic
## 2 Alternative Marine Fuel Selection Problem  
A requirement for reduction of environmental impact from marine coastal traffic was a motivation to consider different mitigation measures. There are numerous studies proposing the methodology of evaluating the environmental impact from marine traffic as well as proposing different solutions. [PERSON] and [PERSON] (2013) described a methodology for estimation of air pollutant emissions from ships, showing that different emissions are present during cruising, maneuvering, and hoteling of ships. [PERSON] and [PERSON] (2014) evaluated the installation of scrubbers as a solution for the reduction of SOx emissions in comparison to low sulfur fuel. Use of alternative fuels in marine transportation is recognized as one of the most effective solutions for mitigation of environmental impact. [PERSON] et al. (2015) evaluated ammonia as a potential marine fuel to reduce the climate impact of shipping considering the short sea ships, deep sea ships, and container ships. [PERSON] and [PERSON] (2016) compared alternative marine fuels by applying a fuzzy group approach, which was used to capture the opinions and preferences form different stakeholders. [PERSON] and [PERSON] (2017) performed an environmental and economical assessment of alternative marine fuels. [PERSON] et al. (2018) in their research performed a life-cycle assessment of a liquified natural gas (LNG)-fueled vessel in domestic services, focusing on the comparative analysis between LNG and conventional marine gas oil (MGO) and showing that the use of LNG can provide substantial benefits considering the environmental point of view. Still, this analysis considers marine transportation on a significantly long travel distance. In this paper, five alternative fuels were selected for the analysis. The general characteristics of each fuel, namely, the flash point, autoignition temperature, flammability limits, toxicity, and price levels, are provided in Table 1. Regarding biofuel, it is important to emphasize that this alternative fuel is considered in a general context; i.e., the exact type of biofuel was not specified for this research. Environmental issues should be primarily considered at the strategic level of planning and decision making, in order to establish a framework for proper selection of mitigation measures and their implementation. Unfortunately, key maritime strategic document in Croatia, such as the Strategy of Maritime Development and Integrated Maritime Policy 2014-2020 (2014), only superficially encompasses environmental issues. Any long-term planning with respect to marine environment protection and mitigation of environmental impact through reduction of acidification, for instance, is still not being considered. In 2016, the Republic of Croatia adopted the Act on the establishment of alternative fuel infrastructure (2014). Alternative fuels encompass electric energy, hydrogen, biofuel, natural gas (LNG), or liquefied petroleum gas (LPG). However, the elements of this Act considering the use of alternative fuels are not mandatory; they only provide a general framework on how to reduce the oil dependence in order to minimize the environmental impact in the future. The latter shows that there are several unresolved issues in the legislative framework of Croatia considering application of alternative fuels, as well as a significant gap between the regulations and practical application. The Adriatic Sea, being one of the most vulnerable of the European seas according to the MSFD (2017), requires appropriate strategies as well as policies to preserve its natural biodiversity and to maintain the sustainable development of the marine environment and coastal area. One of the potential solutions could be switching to more environmentally friendly fuel alternatives for coastal transportation. Use of environmentally friendly fuel in coastal marine traffic could certainly contribute to sustainable traffic development by reducing greenhouse gas and other emissions.