An integrated assessment of the safety, economic, and environmental impacts of hydrogen refueling stations in comparison to conventional fuel stations

This work presents a comparative sustainability assessment of hydrogen refueling stations with respect to vehicle refueling stations supplying conventional fuels. The assessment considers the integrate contribution of process economics, environmental impacts, and process safety, to represent all the pillars of sustainability. The comparison is among hydrogen (stored at the refueling station either as compressed gas vs. liquid) with respect to gasoline, diesel, liquefied petroleum gas, compressed and liquefied natural gas, and an e-charging station. The impacts related to each pillar of sustainability are quantified using key performance indicators, which are aggregated (by means of Analytic Hierarchy Process) into a single metric, called the Overall Sustainability Index (OSI), to obtain a ranking of the refueling alternatives. An uncertainty analysis (using Monte Carlo method) is also presented to discuss the robustness of the ranking. The results show that liquefied hydrogen refueling stations obtain better performance when environmental and economic aspects are preferred in the evaluation of the OSI. On the other hand, safety concerns of the novel hydrogen-based technologies make conventional fuels, such as LPG, better alternative due to the technical maturity and consolidated design practices. Finally, a sensitivity analysis with respect to main parameters affecting the calculation of the key performance indicators is also presented to draw broader conclusions.