Well-to-wheels analysis of fuel-cell vehicle/fuel systems.

Major automobile companies worldwide are undertaking vigorous research and development efforts aimed at developing fuel-cell vehicles (FCVs). Proton membrane exchange (PEM)-based FCVs require hydrogen (H{sub 2}) as the fuel-cell (FC) fuel. Because production and distribution infrastructure for H{sub 2} off board FCVs as a transportation fuel does not exist yet, researchers are developing FCVs that can use hydrocarbon fuels, such as methanol (MeOH) and gasoline, for onboard production of H{sub 2} via fuel processors. Direct H{sub 2} FCVs have no vehicular emissions, while FCVs powered by hydrocarbon fuels have near-zero emissions of criteria pollutants and some carbon dioxide (CO{sub 2}) emissions. However, production of H{sub 2} can generate a large amount of emissions and suffer significant energy losses. A complete evaluation of the energy and emission impacts of FCVs requires an analysis of energy use and emissions during all stages, from energy feedstock wells to vehicle wheels--a so-called ''well-to-wheels'' (WTW) analysis. This paper focuses on FCVs powered by several transportation fuels. Gasoline vehicles (GVs) equipped with internal combustion engines (ICEs) are the baseline technology to which FCVs are compared. Table 1 lists the 13 fuel pathways included in this study. Petroleum-to-gasoline (with 30-ppm sulfur [S] content) is the baseline fuel pathway for GVs