Method and apparatus for removing sulfur from a hydrocarbon fuel
AssigneeBallard Power Systems Inc.
InventorsBenny W. Chow, Leonard McNeilly
Life of this patent
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Abstract
A desulfurization unit is provided. In one embodiment, the present desulfurization unit comprises: a first adsorbent bed having an inlet for receiving a hydrocarbon fuel stream and comprising an adsorbent selected from the group consisting of metal oxides and zeolites; a downstream nickel adsorbent bed; and a downstream guard bed comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites. Processes for desulfurizing hydrocarbon fuel streams employing the present desulfurization unit are provided. Fuel cell electric power generation systems employing the present desulfurization unit are also provided.
Claims75
A desulfurization unit comprising:
- (a) a first adsorbent bed having an inlet for receiving a hydrocarbon fuel stream and comprising an adsorbent selected from the group consisting of metal oxides and zeolites;
- (b) a nickel adsorbent bed downstream of the first bed;
- and
- (c) a guard bed downstream of the first bed and comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites.
A desulfurization unit comprising:
- (a) a vessel having an inlet and outlet for receiving and discharging a hydrocarbon fuel stream;
- (b) a first bed disposed in an upstream portion of the vessel, the first bed comprising an adsorbent selected from the group consisting of metal oxides and zeolites;
- (c) a second bed disposed in a downstream portion of the vessel, the second bed comprising a nickel adsorbent;
- and
- (d) a guard bed disposed in a downstream portion of the vessel, the guard bed comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites.
A desulfurization unit comprising:
- (a) a first bed for adsorbing primary sulfur compounds from a hydrocarbon fuel stream;
- (b) a second bed for adsorbing secondary sulfur compounds from the fuel stream;
- and
- (c) a guard bed for adsorbing primary and secondary sulfur compounds from the fuel stream,
- wherein the first bed is upstream of the second bed and the guard bed.
A process for reducing the sulfur content of a hydrocarbon fuel stream comprising primary sulfur compounds to ≦1 ppm, the process comprising:
- (a) heating the fuel stream to a temperature greater than or equal to the thermal decomposition temperature of at least a portion of the primary sulfur compounds;
- (b) directing the fuel stream to a first bed comprising an adsorbent selected from the group consisting of metal oxides and zeolites;
- (c) directing the heated fuel stream to a nickel adsorbent bed downstream of the first bed;
- and
- (d) directing the heated fuel stream to a guard bed downstream of the second bed, the guard bed comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites.
A process for reducing the sulfur content of a hydrocarbon fuel stream comprising secondary sulfur compounds to ≦1 ppm, the process comprising:
- (a) directing the fuel stream to a first bed comprising an adsorbent selected from the group consisting of metal oxides and zeolites;
- (b) directing the fuel stream to a guard bed downstream of the first bed, the guard bed comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites;
- and
- (c) directing the fuel stream to a third bed downstream of the guard bed, the third bed comprising a nickel adsorbent.
A fuel cell electric power generation system comprising:
- (a) a fuel processing system for converting a hydrocarbon fuel stream to a reformate stream comprising hydrogen, the fuel processing system comprising a desulfurization unit comprising:
- (i) a metal oxide adsorbent bed;
- (ii) a nickel metal adsorbent bed downstream of the metal oxide bed;
- and
- (iii) a copper-zinc guard bed downstream of the metal oxide bed;
- and
- (b) a fuel cell stack for receiving the reformate and connectable to an electrical load.
A method of operating a fuel cell electric power generation system comprising
- a fuel processing system for converting a hydrocarbon fuel stream to a reformate stream comprising hydrogen, the fuel processing system comprising a desulfurization unit, the desulfurization unit comprising
- a metal oxide adsorbent bed,
- a nickel metal adsorbent bed downstream of the metal oxide bed, and
- a copper-zinc guard bed downstream of the metal oxide bed, and
- a fuel cell stack for receiving the reformate and connectable to an electrical load, the method comprising:
- (a) directing the fuel stream to a first bed comprising an adsorbent selected from the group consisting of metal oxides and zeolites, and having a first minimum operating temperature;
- (b) directing the fuel stream to a downstream second bed comprising a nickel adsorbent, and having a second minimum operating temperature;
- (c) directing the fuel stream to a downstream guard bed comprising an adsorbent selected from the group consisting of copper-zinc adsorbents, activated alumina, activated carbon, and zeolites, and having a third minimum operating temperature lower than the first and second minimum operating temperatures;
- and
- (d) heating the fuel stream to a process temperature that is higher than or equal to any of the first, second and third minimum operating temperatures.
Dependencies are inferred from the claim text.