NOVELTY - Process for desulfurization of a hydrocarbon feed stream, comprises: providing a hydrocarbon feed stream, contaminated with sulfur compounds; passing the sulfur contaminated feed stream through a zeolite Y adsorbent; and subsequently passing the feed stream through a selective sulfur adsorbent, where the feed stream is substantially desulfurized.    USE - The process is useful for desulfurizing hydrocarbon feed stream and a hydrocarbon fuel cell feed stream. The sulfur adsorbent system is useful for removing sulfur from a hydrocarbon used in a fuel cell processing train (claimed). The process is useful for hydrogen generation useful in a fuel cell processing train (preferably proton exchange membrane fuel cell), which is useful in an automobile.    ADVANTAGE - The process: desulfurizes the sulfur containing hydrocarbon feed stream to about 50 ppb or less; and produces a substantially desulfurized hydrocarbon fuel stream at temperatures less than 100 degrees C, even if water is present in the fuel stream. The system: adsorbs substantial quantities of a wide range of sulfur compounds, including dimethyl sulfide, various mercaptans, such as ethyl mercaptan and tertiary butyl mercaptan, hydrogen sulfide, carbonyl sulfide, tetrahydro thiophene, disulfides, sulfoxides, other organic sulfides and/or various higher molecular weight sulfur-containing compounds; and is a improved desulfurization systems, which absorbs the above broad range of sulfur compounds effectively for an extended period of time to delay breakthrough of sulfur compounds as long as possible. The desulfurization system can be substantially enhanced by utilizing a zeolite Y adsorbent, preferably exchanged with copper cations, i.e. the system performs surprisingly better than any of the individual selective sulfur adsorbents or the copper exchanged zeolite Y, when used individually. The sequential sulfur adsorbent system is not subjected to desorption of the adsorbed sulfur compounds when the conditions surrounding the sulfur adsorbent system change, as often occurs with some conventional sulfur adsorbents.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a process for desulfurization of a hydrocarbon fuel cell feed stream comprising: providing a hydrocarbon feed stream contaminated with sulfur compounds; passing the sulfur contaminated feed stream through a sequential sulfur adsorbent system comprising a zeolite Y ion exchanged with a cation comprising copper (Cu), silver (Ag), manganese (Mn), magnesium (Mg), iron (Fe), calcium (Ca), cerium (Ce), lanthanum (La), strontium (Sr), praseodymium (Pr) and/or neodymium (Nd), and a selective sulfur adsorbent comprising manganese compound(s) and copper oxide, manganese compound(s) and iron oxide, and manganese compound(s), iron oxide and copper oxide, in sequence, to produce a hydrocarbon feed stream which has been substantially desulfurized; and delivering the substantially desulfurized hydrocarbon feed stream to a fuel cell processing train; and    (2) a sulfur adsorbent system for use in removing sulfur from a hydrocarbon used in a fuel cell processing train, comprising: zeolite Y adsorbent ion exchanged with a cation comprising Cu, Ag, Mn, Mg, Fe, Ca, Ce, La, Sr, Pr and/or Nd and a selective sulfur adsorbent, where the sulfur adsorbent system is configured such that the hydrocarbon sequentially passes through the zeolite Y adsorbent and then the selective sulfur adsorbent.