Hybrid reformer for fuel flexibility
View Patent ↗A reformer for a fuel cell system includes a leading segment and a trailing segment. The leading segment includes less reactive catalyst and/or more stabilizing catalyst than the trailing segment. The reformer may be used for reformation of high and low hydrocarbon fuels.
1. A fuel cell system, comprising:
a high temperature fuel cell stack;
a reformer which comprises a leading segment and a trailing segment, wherein the leading segment comprises less reactive catalyst than the trailing segment, and wherein the leading segment and the trailing segment are located in a same reformer housing, and wherein the reactive catalyst comprises nickel; and
wherein the reformer housing is external to the high temperature fuel cell stack.
2. The fuel cell system of claim 1 , wherein the leading segment contains a lower amount of nickel than the trailing segment.
3. The fuel cell system of claim 1 , wherein the leading segment contains a lower nickel concentration than the trailing segment.
4. The fuel cell system of claim 1 , wherein nickel amount or concentration increases between the leading segment and the trailing segment in a single step or in a graded fashion.
5. The fuel cell system of claim 1 , wherein:
a rhodium stabilizing catalyst is located in the reformer; and
the leading segment of the reformer comprises more of the rhodium stabilizing catalyst than the trailing segment.
6. The fuel cell system of claim 1 , wherein:
the at least one fuel cell stack comprises an internal or an external reformation type solid oxide fuel cells;
the reformer comprises an external reformer; and
the reformer is thermally integrated with the at least one fuel cell stack.
7. The fuel cell system of claim 6 , further comprising a burner which is thermally integrated with the reformer.
8. The fuel cell system of claim 1 , wherein the fuel cell stack comprises a solid oxide fuel cell stack.
9. A fuel cell system, comprising:
a high temperature fuel cell stack;
a reformer which comprises a leading segment and a trailing segment;
wherein:
the leading segment comprises more stabilizing catalyst than the trailing segment;
the leading segment comprises not more reactive catalyst than the trailing segment;
the reactive catalyst comprises nickel and the stabilizing catalyst comprises rhodium;
and
the leading segment and the trailing segment are located in a same reformer housing;
and
wherein the reformer housing is external to the high temperature fuel cell stack.
10. The fuel cell system of claim 9 , wherein:
the leading segment of the reformer comprises a higher amount or concentration of the rhodium catalyst than the trailing segment; and
the leading segment of the reformer comprises a lower amount or concentration of the nickel catalyst than the trailing segment.
11. The fuel cell system of claim 9 , wherein:
the leading segment of the reformer comprises a higher amount or concentration of the rhodium catalyst than the trailing segment; and
the leading segment of the reformer comprises a substantially equal amount or concentration of the nickel catalyst as the trailing segment.
12. The fuel cell system of claim 9 , wherein the fuel cell stack comprises a solid oxide fuel cell stack.