Life cycle analysis of hydrotreated vegetable oils production based on green hydrogen and used cooking oils

• Life cycle analysis for Hydrotreated Vegetable Oil production using green hydrogen. • Palm oil and the electricity grid choices are also investigated. • The lowest environmental impacts are when using renewable electricity scenarios. • Green hydrogen production achieves an 80 % reduction in global warming potential. Hydrotreated Vegetable Oils (HVOs) have won significant attention worldwide as a viable alternative to fossil diesel in transportation. In the present study, a life cycle analysis (LCA) of the production of HVO is conducted, focused on HVO in the case of Portugal. The production process considered exploits used cooking oils (UCOs), alongside green hydrogen (GH 2 ). SimaPro software is used to analyse the environmental impacts of the entire value chain associated with the production of GH 2 and HVO. The resulting environmental impacts are also compared with other conventional scenarios that include using virgin oils and the grid mix electricity. The LCA results demonstrated that the HVO produced using GH 2 and UCO has a reduction in environmental impacts by around 0.23 to 0.45 kg CO 2 eq./kg HVO compared to the conventional scenarios. The lowest GWP level observed is in the UCO with PV/Wind electricity scenario at 0.304 kg CO 2 eq/kg HVO, While the highest GWP is for using Palm Oil with grid mix at 0.748 kg CO 2 eq/kg HVO. These findings underscore the significant influence of electricity sources and feedstock type on the GWP values in HVO production.