Desulfurization system and method for desulfurizing a fuel stream

Abstract

A method for producing a substantially desulfurized hydrocarbon fuel stream at temperatures less than 100° C. including providing a nondesulfurized fuel cell hydrocarbon fuel stream and passing the fuel stream through a sequential sulfur adsorbent system containing calcium exchanged zeolite, hydrated alumina and a selective sulfur adsorbent placed in sequence to produce a substantially desulfurized hydrocarbon fuel stream.

1 . A process for desulfurization of a hydrocarbon feed stream comprising 
 providing a hydrocarbon feed stream, which is contaminated with sulfur compounds, including carbonyl sulfide,    passing the sulfur contaminated feed stream through a sequential sulfur adsorbent system comprising in sequence zeolite, hydrated alumina, and a selective sulfur adsorbent to produce a hydrocarbon feed stream which has been substantially desulfurized.    
     
     
         2 . The process of  claim 1 , where the zeolite comprises a calcium exchanged zeolite X or LSX.  
     
     
         3 . The process of  claim 2 , wherein the calcium exchanged zeolite X or LSX is exchanged with calcium ions at least about 50%.  
     
     
         4 . The process of  claim 3 , wherein the calcium exchanged zeolite X or LSX is further exchanged with metal ions selected from the group consisting of zinc, cadmium, cobalt, nickel, copper, iron, manganese, silver, gold, scandium, lithium and combinations thereof.  
     
     
         5 . The process of  claim 1 , wherein the Si:Al ratio of the zeolite is from about 1.0 to about 1.25.  
     
     
         6 . The process of  claim 1 , wherein the composition of the hydrated alumina is selected from boehmite, pseudo-boehmite and gibbsite.  
     
     
         7 . The process of  claim 1 , wherein the composition of the hydrated alumina is selected from Al(OH) 3  and AlO(OH).  
     
     
         8 . The process of  claim 1 , wherein the selective sulfur absorbent comprises zinc oxide, copper oxide and a binder.  
     
     
         9 . The process of  claim 1 , wherein the selective sulfur absorbent comprises copper oxide and one or more manganese compounds.  
     
     
         10 . The process of  claim 1 , wherein the selective sulfur absorbent comprises one or more manganese compounds and an iron compound.  
     
     
         11 . The process of  claim 1 , wherein the temperature of the sequential sulfur adsorbent system, as the feed stream passes therethough, is from ambient to about 100° C.  
     
     
         12 . The process of  claim 1 , wherein the temperature of the sequential sulfur adsorbent system, as the feed stream passes therethough, is from ambient to about 60° C.  
     
     
         13 . The process of  claim 1 , wherein the feed stream contacts the zeolite prior to contacting either the hydrated alumina or the selective sulfur absorbent.  
     
     
         14 . The process of  claim 1 , wherein the feed stream contacts the zeolite prior to contacting the hydrated alumina and contacts the selective sulfur adsorbent after contacting the hydrated alumina.  
     
     
         15 . A process for desulfurization of a hydrocarbon fuel cell feed stream comprising 
 providing a hydrocarbon feed stream to a fuel cell processing train, wherein the feed stream is contaminated with sulfur compounds, including carbonyl sulfide,    passing the sulfur contaminated feed stream through a sequential sulfur adsorbent system comprising, in sequence, calcium-exchanged zeolite, hydrated alumina and a selective sulfur adsorbent to produce a hydrocarbon feed stream which has been substantially desulfurized, and    delivering the substantially desulfurized hydrocarbon feed stream to remaining components of the fuel cell processing train.    
     
     
         16 . The process of  claim 15 , wherein the temperature of the sequential sulfur adsorbent system as the feed stream passes therethough is from ambient to about 100° C.  
     
     
         17 . A process for the desulfurization of a hydrocarbon fuel cell feed stream comprising 
 providing the hydrocarbon feed stream to a fuel cell processing train, wherein the feed stream is contaminated with sulfur compounds, including one or more compounds selected from the group consisting of carbonyl sulfide, hydrogen sulfide, tetra hydro thiophene, dimethyl sulfide, mercaptans, disulfides, thiophenes, sulfoxides, other organic sulfides, and higher molecular weight organic sulfur compounds and combinations thereof,    passing the sulfur contaminated feed stream through a sequential sulfur adsorbent system comprising, in sequence, calcium exchange zeolite X or LSX, hydrated alumina, selected from the group consisting of boehmite, pseudo-boehmite and gibbsite and mixtures thereof, and a selective sulfur adsorbent selected from the group consisting of a blend of components selected from a) copper oxide, a manganese compound and a binder; b) copper oxide, a zinc compound and a binder, and c) a manganese compound, an iron compound and a support to produce a hydrocarbon feed stream which has been substantially desulfurized, and    delivering the substantially desulfurized hydrocarbon feed stream to remaining components of the fuel cell processing train.    
     
     
         18 . The process of  claim 17 , wherein the temperature of the sequential sulfur adsorbent system as the feed stream passes therethrough is from ambient to about 100° C.  
     
     
         19 . The process of  claim 17 , wherein the pressure of the sulfur contaminated feed stream as it passes through the sequential sulfur adsorbent system is from about 1 bar to about 18 bar.  
     
     
         20 . A sequential adsorbent system for use in a fuel cell processing train comprising in sequence calcium exchanged zeolite, hydrated alumina and a selective sulfur adsorbent, wherein the calcium exchanged zeolite comprises calcium exchanged zeolite X or LSX ion exchanged to at least 50% of the available metal ions with calcium ions; wherein the hydrated alumina is selected from the group consisting of gibbsite, boehmite, pseudo-boehmite and mixtures thereof; and wherein the selective sulfur adsorbent comprises from about 60 to about 80% by weight of one or more manganese compounds selected from the group consisting of MnO 2 , Mn 2 O 3 , Mn 3 O 4  and Mn(OH) 4  and mixtures thereof, from about 15 to about 40% by weight of copper oxide, and a binder.  
     
     
         21 . A sequential adsorbent system for use in a fuel cell processing train comprising in sequence calcium exchanged zeolite, wherein the calcium exchanged zeolite comprises calcium exchanged zeolite X or LSX, ion exchanged to at least 50% of the available metal ions with calcium ions; hydrated alumina selected from the group consisting of gibbsite, boehmite, pseudo-boehmite and mixtures thereof, and a selective sulfur adsorbent comprising from about 15 to about 40 copper oxide, from about 5 to about 15 of a zinc compound and at least about 40% alumina.  
     
     
         22 . A sequential adsorbent system for use in a fuel cell processing train comprising in sequence calcium exchanged zeolite X or LSX, ion exchanged to at least 50% of the available metal ions with calcium cations; hydrated alumina selected from the group consisting of gibbsite, boehmite, pseudo-boehmite and mixtures thereof, and a selective sulfur adsorbent comprising from about 20 to about 40% of a manganese compound or compounds selected from the group consisting of MnO 2 , Mn 2 O 3 , Mn 3 O 4 , Mn(OH) 4  and mixtures thereof, from about 40 to about 80% of iron oxide, and a support.