Comparative LCA assessment of diesel oil and hydrogen internal combustion engines for power generation

The present thesis is part of a broader project which main objectives is the engineering of a newly conceived mono-fuel hydrogen internal combustion engine (ICE), which will allow a reduction of emissions and cost with respect to the nowadays fossil fueled based powertrains. The range of applications is wide and space from automotive to offroad to power generation. In the present study, the primary aim is to analyze the environmental footprint of a hydrogen fueled engine achieved by retrofitting an existing diesel-powered ICE with a purposely made conversion procedure. One significant advantage of this retrofit technique is its ability to exploit existing infrastructure, allowing for a smoother and faster shift to greener energy sources. The Life Cycle Assessment (LCA) methodology is applied to provide an extensive cradle-to-grave evaluation of its environmental impact across all the stages of its entire life cycle, from raw material extraction to manufacturing, operation, and end-of-life. The analysis has been carried out using both primary data (i.e., company-specific material and energy flows are used), and literature data (i.e., electrolyzer construction, material used in hydrogen production plant). An important focus on the use phase has been carried out considering, in a very detailed way, the hydrogen production methods adopting current technologies (i.e., steam methane reforming, grid fed electrolysis, coal gasification), and future scenarios (i.e., carbon capture and storage coupled with the fossil-based production methods, electrolysis completely sustained by renewable resources) as they deeply affect the final outcomes. The most relevant impact categories taken into account are climate change, use of fossil resources, freshwater ecotoxicity, acidification and particulate matter. The achieved results display that today technologies are not yet competitive in reducing the overall environmental impact, as they are still too much based-on fossil resources, but the adoption of new and more sustainable apparatus in the following years is going to be a game changer.