Techno-economic assessment of alternative fuels in maritime applications

This work focused on the techno-economic assessment of alternative fuels, including hydrogen, ammonia, methanol, and natural gas, in the case of their utilisation in port areas. Different production routes were investigated, including processes based on green hydrogen production, carbon dioxide capture and methanation. Based on the developed process schemes and balances, the main equipment was identified and preliminarily designed, and energy requirements were assessed. The estimated values were considered as the basis for the economic analysis, including the estimation of capital expenditure (CAPEX), operating expenditure (OPEX), and levelized cost of fuel (LCOF). The influence of relevant technical and economic parameters was also investigated through sensitivity analyses in order to identify the main factors affecting the competitiveness of the considered production pathways. The price of electricity and hydrogen production route were found to be particularly affecting the overall viability of the analysed alternatives. In particular, the availability of low-cost electricity plays a decisive role in determining the feasibility of all pathways. Future reductions in renewable electricity prices, particularly in the range of 30–50 €/MWh, could significantly improve economic performance, also in view of their indirect impacts on the production cost of green hydrogen, considered in this work as an intermediate for all the analysed production pathways. The results obtained allowed the different alternative fuel routes to be compared on a consistent basis, highlighting their main technical and economic characteristics and the factors that most strongly influence production costs.