Fuel cell systems
View Patent ↗Fuel cell systems and methods of operating fuel cell systems are disclosed. In some embodiments, the systems and methods include an emission control system that reduces an amount of organic emission(s) released from the fuel cell systems. The organic emission(s) can include, for example, methanol, formic acid, and/or formaldehyde.
1. A fuel cell system, comprising:
an outlet;
a fuel cell stack in fluid communication with the outlet;
an organic fuel in fluid communication with the fuel cell stack; and
an emission control system in fluid communication with the outlet, the control system capable of reducing an amount of an organic emission from the outlet by absorption, adsorption, catalysis and/or chemical reaction with the emission,
wherein the fuel cell system is a direct methanol fuel cell system.
2. The system of claim 1 , wherein the organic emission is selected from the group consisting of methanol, formic acid, and formaldehyde.
3. The system of claim 1 , wherein the outlet is an anode outlet.
4. The system of claim 1 , wherein the outlet is a cathode outlet.
5. The system of claim 1 , wherein the emission control system comprises a packed bed.
6. The system of claim 5 , wherein the packed bed includes a material is selected from the group consisting of activated carbon, potassium permanganate, elumine, and lanthanum oxide.
7. The system of claim 1 , wherein the emission control system comprises a substrate and a first material dispersed on the substrate, the first material capable of reducing the amount of the organic emission.
8. The system of claim 7 , wherein the first material is selected from the group consisting of activated carbon, potassium permanganate, elumine, and lanthanum oxide.
9. The system of claim 1 , wherein the organic fuel and the emission control system are components of a modular system.
10. The system of claim 1 , further comprising a mechanism adapted to restrict gas flow to the fuel cell stack.
11. The system of claim 10 , wherein the mechanism comprises a pressure-sensitive valve.
12. The system of claim 11 , wherein the pressure-sensitive valve comprises a slit valve.
13. The system of claim 10 , wherein the mechanism comprises a shape memory material.
14. The system of claim 10 , wherein the mechanism is adapted to restrict gas flow through the outlet.
15. The system of claim 10 , wherein the mechanism is adapted to restrict gas flow through an inlet in fluid communication with the fuel cell stack.
16. The system of claim 1 , wherein the organic fuel comprises an alcohol.
17. The system of claim 16 , wherein the alcohol comprises methanol.
18. The system of claim 1 , wherein the fuel cell stack comprises a fuel cell having a gas diffusion layer having a first material capable of reducing an amount of the organic emission that contacts the first material.
19. The system of claim 18 , wherein the first material is selected from the group consisting of platinum, palladium, ruthenium, osmium, and iridium.
20. The system of claim 18 , wherein the first material comprises an oxide.
21. A fuel cell system, comprising a fuel cell including a cathode, an anode, and a gas diffusion layer different from the cathode and the anode, the gas diffusion layer having dispersed therein a first material capable of reducing an amount of an organic emission that contacts the first material.
22. The system of claim 21 , wherein the first material is dispersed in the gas diffusion layer at less than about 0.1 mg/cm 2 .
23. The system of claim 21 , wherein the first material is dispersed in the gas diffusion layer at less than about 0.05 mg/cm 2 .
24. The system of claim 21 , wherein the first material is dispersed in the gas diffusion layer at less than about 0.01 mg/cm 2 .
25. The system of claim 21 , wherein the first material is selected from the group consisting of platinum, palladium, ruthenium, osmium, and iridium.
26. The system of claim 21 , wherein the first material comprises an oxide.
27. The system of claim 26 , wherein the oxide is selected from the group consisting of platinum oxide, ruthenium oxide, manganese oxide, and chromium oxide.
28. The system of claim 21 , wherein the organic emission is selected from the group consisting of methanol, formic acid, and formaldehyde.
29. A method of operating a fuel cell system, the method comprising:
contacting an organic fuel to a catalyst of a fuel cell in the fuel cell system; and
reducing an amount of an organic emission from an outlet of the fuel cell system by absorption, adsorption, catalysis, and/or chemical reaction with the organic emission,
wherein the fuel cell system is a direct methanol fuel cell system.
30. The method of claim 29 , wherein the organic emission is selected from the group consisting of methanol, formic acid, and formaldehyde.
31. The method of claim 29 , comprising contacting emission from the outlet with a first material capable of reducing an amount of methanol from the outlet.
32. The method of claim 31 , wherein the first material comprises carbon.
33. The method of claim 29 , comprising contacting emission from the outlet with a first material capable of reducing an amount of formic acid from the outlet.
34. The method of claim 33 , wherein the first material comprises lanthanum oxide or carbon.
35. The method of claim 29 , comprising contacting emission from the outlet with a first material capable of reducing an amount of formaldehyde from the outlet.
36. The method of claim 35 , wherein the first material comprises potassium permanganate or elumine.
37. The method of claim 29 , wherein the organic fuel comprises an alcohol.
38. The method of claim 37 , wherein the alcohol comprises methanol.
39. The method of claim 29 , wherein the outlet is an anode outlet.
40. The method of claim 30 , wherein emission from the anode outlet comprises methanol, and further comprising introducing the methanol from the anode outlet to the fuel cell.
41. The method of claim 29 , wherein the outlet is a cathode outlet.
42. The method of claim 29 , further comprising contacting the organic emission with a first material dispersed in a gas diffusion layer of the fuel cell, the first material capable of reducing an amount of the organic emission.
43. The method of claim 42 , wherein the first material is selected from the group consisting of platinum, palladium, ruthenium, osmium, and iridium.
44. The system of claim 42 , wherein the first material comprises an oxide.