Integrated fuel cell system
AssigneeIdaTech, LLC
InventorsDavid J. Edlund, William A. Pledger
Life of this patent
Estimating the term…
Abstract
The invented system includes a fuel-cell system comprising a fuel cell that produces electrical power from air (oxygen) and hydrogen, and a fuel processor that produces hydrogen from a variety of feedstocks. One such fuel processor is a steam reformer which produces purified hydrogen from a carbon-containing feedstock and water. In the invented system, various mechanisms for implementing the cold start-up of the fuel processor are disclosed, as well as mechanisms for optimizing and/or harvesting the heat and water requirements of the system, and maintaining desired the feed ratios of feedstock to water in the fuel processor and purity of the process water used in the system.
Claims32
A processing system, comprising:
- a fuel processor adapted to receive a feed stream containing a carbon-containing feedstock and water and to produce a product hydrogen stream therefrom, wherein the fuel processor includes a hydrogen-production region, in which the feed stream is reacted at an elevated temperature in the presence of a steam reforming catalyst to form a mixed gas stream containing hydrogen gas and other gases, and further wherein the fuel processor includes a separation region adapted to separate the mixed gas stream into a stream containing at least substantially pure hydrogen gas from which the product hydrogen stream is formed and a byproduct stream containing at least a substantial portion of the other gases;
- a feedstock reservoir containing a liquid carbon-containing feedstock;
- a water reservoir containing water;
- and
- a pump assembly adapted to draw a liquid feedstock stream containing feedstock from the feedstock reservoir and a liquid water stream containing water from the water reservoir and to deliver the feedstock stream and the water stream to the fuel processor, wherein the pump assembly includes a plurality of synchronized pump heads adapted to pump fluid from a corresponding plurality of pump cavities, wherein one of the pump cavities is adapted receive feedstock from the feedstock reservoir and one of the pump cavities is adapted to receive water from the water reservoir.
In a fuel processing system having a hydrogen-production region, in which a mixed gas stream containing hydrogen gas and other gases is produced by steam reforming from a feed stream containing a carbon-containing feedstock and water, and a separation region, in which the mixed gas stream is separated using at least one hydrogen-selective membrane into a hydrogen-rich stream from which a product hydrogen stream is formed and a byproduct stream containing at least a substantial portion of the other gases, a method for starting up the fuel processing system comprising:
- delivering a stream containing hydrogen gas from a hydrogen storage vessel to a combustion region and combusting the stream to produce a heated fluid stream;
- heating the hydrogen-production region with the heated fluid stream until the hydrogen-production region reaches a temperature of at least approximately 250° C.;
- delivering a feed stream containing water and a carbon-containing feedstock to the hydrogen-production region to produce by steam reforming the mixed gas stream;
- separating the mixed gas stream into the hydrogen-rich stream and the byproduct stream;
- delivering at least a portion of the hydrogen-rich stream to the hydrogen storage vessel to at least partially recharge the hydrogen storage vessel, delivering the byproduct stream to the combustion region, and reducing the flow of the stream containing hydrogen gas to the combustion region;
- and
- delivering at least a portion of the hydrogen-rich stream to a fuel cell stack to produce an electric current therefrom.
A fuel cell system, comprising:
- a fuel processor adapted to receive a feed stream containing a carbon-containing feedstock and to produce a byproduct stream and a product hydrogen stream containing hydrogen gas therefrom, wherein the fuel processor includes a hydrogen-production region, in which the feedstock is reacted at an elevated temperature to form a product stream containing hydrogen gas, and a separation region containing at least one hydrogen-selective membrane adapted to separate the product stream into the product hydrogen stream and a byproduct stream;
- a fuel cell stack adapted to receive the product hydrogen stream and produce an electric current therefrom, wherein the fuel cell stack includes a cathode chamber and an anode chamber and is further adapted to produce a water stream that is removed from the cathode chamber of the fuel cell stack;
- and
- a cooling assembly that is adapted to receive and cool the water stream and then deliver the water stream to the fuel cell stack to cool the fuel cell stack, wherein the cooling assembly includes an ion-exchange bed through which at least a portion of the water stream is passed to remove ions from the water stream.
Dependencies are inferred from the claim text.