Environmental Evaluation of Direct Hydrogen and Reformer-Based Fuel Cell Vehicles 2002-01-0094
Fuel cells have attracted a great deal of attention in the last few years as potential replacements for conventional gasoline- or diesel-powered internal combustion engines. This study evaluated the potential life-cycle environmental impacts of a fuel cell vehicle (FCV) using a 50 kW proton exchange membrane (PEM) fuel cell system (both with and without a fuel reformer), and compared them with those of a gasoline-fueled internal combustion engine vehicle (ICEV). The fuels considered for the fuel cell systems were direct hydrogen (without reformer), and methanol and gasoline (with reformer). Exclusive of the propulsion systems, the rest of the vehicle was assumed to be the same across all the profiles.
The hydrogen FCV is found to have the lowest impact scores in 12 of the 14 impact categories evaluated (see Appendix A for impact category definitions), mainly because of zero air emissions from driving and the lowest total lifetime quantity by mass of fuel (hydrogen) required during use. In 5 of these 12 categories, the gasoline FCV is a close second.
An additional long-term scenario for the gasoline FCV assumed a much lower platinum content and reduced overall weight (reduced by ∼ 220 kg). This vehicle has the lowest impact scores in 3 categories (nonrenewable resource use, energy use, and smog formation), while the hydrogen FCV still leads in the other nine impact categories. Also, the long-term gasoline FCV's scores are much closer to the hydrogen FCV's scores. The hydrogen FCV, however, still remains the most environmentally preferable vehicle.