Fuel cell system and desulfurization system
One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
1. A method of operating a desulfurization system, comprising:
providing a sulfur-oxidation catalyst comprising at least one Group VIII noble metal and iron, wherein the iron comprises 0.5% to 40% by weight;
supplying a sulfur-containing fuel and an oxidant to the sulfur oxidation-catalyst;
contacting the sulfur oxidation-catalyst with the fuel and the oxidant; and
oxidizing sulfur in the fuel using the oxidant and the sulfur-oxidation catalyst.
2. The method of claim 1 , further comprising:
providing a sulfur oxide trap; and
removing at least a portion of the oxidized sulfur from the fuel with the sulfur oxide trap; and
providing desulfurized fuel.
3. The method of claim 2 , wherein said sulfur oxide trap comprises alkali metal oxides, alkaline earth oxides or base metal oxides configured to remove the sulfur oxides from the fuel by absorption.
4. The method of claim 1 , wherein the at least one Group VIII noble metal comprises platinum, palladium, rhodium, iridium or a combination thereof.
5. The method of claim 4 , wherein the at least one Group VIII noble metal comprises platinum.
6. The method of claim 1 , wherein the amount of oxidant supplied to the sulfur-oxidation catalyst is selected to effect the selective oxidation of sulfur in the fuel while preventing the combustion of the fuel.
7. The method of claim 1 , where said oxidant is O 2 , and wherein the ratio of O 2 , from said oxidant, and sulfur, from said fuel, supplied to the sulfur-oxidation catalyst is greater than or equal to 10.
8. The method of claim 1 , where said oxidant is O 2 , and wherein the ratio of O 2 from said oxidant and carbon from said fuel supplied to the sulfur-oxidation catalyst is less than or equal to 0.5.
9. The method of claim 8 , wherein the ratio of O 2 from said oxidant and carbon from said fuel supplied to the sulfur-oxidation catalyst is between 0.001 and 0.3.
10. The method of claim 1 , wherein said desulfurization system is operated at a temperature between 150° C. and 600° C.
11. The method of claim 10 , wherein said desulfurization system is operated at a temperature between 200° C. and 450° C.
12. The method of claim 1 , wherein said sulfur-oxidation catalyst further comprises at least one promoter element configured to promote sulfur oxidation.
13. The method of claim 12 , wherein the at least one promoter element comprises at least one element selected from the group consisting of Groups IIa-VIIa, Groups Ib-Vb, Lanthanide Series and Actinide Series elements.
14. The method of claim 13 , wherein the at least one promoter element comprises 0.01% to 10% by weight.
15. The method of claim 14 , wherein the at least one promoter element comprises 0.1% to 5% by weight.
16. A method of desulfurizing a fuel, comprising:
providing a desulfurization system comprising:
a sulfur-oxidation catalyst comprising platinum; iron, wherein the iron comprises 0.5% to 40% by weight; and at least one promoter element selected from the group consisting of Groups IIa-VIIa, Groups Ib-Vb, Lanthanide Series and Actinide Series elements, wherein the at least one promoter element comprises 0.1% to 5% by weight;
a sulfur oxide trap comprising alkali metal oxides, alkaline earth oxides or base metal oxides configured to adsorb the sulfur oxides;
wherein said desulfurization system is operated at a temperature between 225° C. and 350° C.;
supplying a sulfur-containing fuel and an oxidant comprising O 2 to the sulfur oxidation catalyst wherein the amount of oxidant supplied is selected to effect the selective oxidation of sulfur in the sulfur-containing fuel while preventing the combustion of the fuel;
mixing the sulfur-containing fuel and the oxidant at a location upstream of the sulfur oxidation-catalyst to form a feed stream, wherein the ratio of O 2 and sulfur in said feed stream is greater than or equal to 10, and wherein the ratio of O 2 and carbon in the feed stream is between 0.001 and 0.05;
contacting the sulfur oxidation-catalyst with feed stream; and
oxidizing sulfur in the feed stream using the oxidant and the sulfur-oxidation catalyst;
absorbing at least a portion of the sulfur oxides in the sulfur oxide trap; and
providing desulfurized fuel to a fuel cell system.
17. The method of claim 16 , wherein the iron comprises 1% to 30% by weight.
18. The method of claim 17 , wherein the iron comprises 2% to 10% by weight.
19. The method of claim 18 , wherein the iron comprises 3% to 7% by weight.
20. The method of claim 19 wherein the iron comprises 4% to 6% by weight.