Abstract
In this work the main objective is to analyze energy consumption and CO2 emissions of biohydrogen for use in the transportation sector in Portugal. A life cycle assessment will be performed in order to evaluate bio-hydrogen pathways, having biodiesel and conventional fossil diesel as reference. The pathways were production of feedstock, pre-treatment, treatment, compression, distribution and applications. For the well-to-tank analysis the SimaPro 7.1 software and excel tools are used. This study includes not only a well-to-tank analysis but also a tank-to-wheel analysis (using ADVISOR software) estimating hydrogen consumption and electricity consumption of a fuel cell hybrid and a plug-in hybrid. Several bio-hydrogen feedstocks to produce hydrogen through fermentation processes will be considered: potato peels. The results are compared with diesel internal combustion engine vehicles running on diesel and biodiesel. The required energy resulting from sunflower, rapeseed/soybean, microalgae and diesel are respectively 0.77, 0.99, 0.75 and 0.16 MJ/MJfuel. The required CO2 emissions resulting are respectively 39, 90, 35 and 14 g/ MJfuel. For hydrogen the respective values are 0.33 MJ/MJfuel and 8.05 g/ MJfuel. The lowest values of fuel life cycle energy consumption and CO2 emissions, excluding plug-in hybrid fuel cell running on hydrogen from natural gas centralized reforming, are for hybrid and plug-in hybrid fuel cell vehicles running on hydrogen from potato peels.
Keywords: bio-hydrogen, life-cycle assessment, bio-diesel, energy consumption, CO2 emissions.