Title of Invention

THERMALLY PRIMED HYDROGEN-PRODUCING FUEL CELL SYSTEM

Abstract Thermally primed fuel processing assemblies and hydrogen-producing fuel cell systems that include the same. The thermally primed fuel processing assemblies include at least one hydrogen-producing region housed within an internal compartment of a heated containment structure. In some embodiments, the heated containment structure is an oven. In some embodiments, the compartment also contains a purification region and/or heating assembly. In some embodiments, the containment structure is adapted to heat and maintain the internal compartment at or above a threshold temperature, which may correspond to a suitable hydrogen-producing temperature. In some embodiments, the containment structure is adapted to maintain this temperature during periods in which the fuel cell system is not producing power and/or not producing power to satisfy an applied load to the system. In some embodiments, the fuel cell system is adapted to provide backup power to a power source, which may be adapted to power the containment structure.
Full Text WO 2007/037856 PCT/US2006/033027
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THERMALLY PRIMED HYDROGEN-PRODUCING FUEL CELL SYSTEM
Related Application
The present application claims priority to similarly entitled U.S. Patent
Application Serial No. 11/229,365, which was filed on September 16, 2005. The
complete disclosure of the above-identified patent application is hereby incorporated by
reference for all purposes.
Field of tlie Disclosure
The present disclosure is directed generally to hydrogen-producing fuel cell
systems, and more particulai'ly, to hydrogen-producing fuel processing systems with
thennally primed hydrogen-producing regions.
Background of the Disclosure
As used herein, a fuel processing assembly is a device or combination of devices
that produces hydrogen gas from one or more feed streams that include one or more
feedstocks. Examples of fuel processing assemblies include steam and autothermal
reformers, in which the feed stream contains water and a carbon-containing feedstock,
such as an alcohol or a hydrocarbon. Fuel processors typically operate at elevated
temperatures. In endothermic fuel processing reactions, such as in steam reforming fliel
processing assemblies, the heat required to heat at least the hydrogen-producing region of
the fuel processing assembly to, and maintain the region at, a suitable hydrogen-
producing temperature needs to be provided by a heating assembly, such as a burner,
electrical heater or the lilce. When burners are used to heat the fuel processor, the burners
typically utilize a combustible fuel stream, such as a combustible gas or a combustible
liquid.
In a hydrogen-producing fuel processing assembly that utilizes a steam reformer,
or steam reforming region, hydrogen gas is produced from a feed stream that includes a
carbon-containing feedstock and water. Steam reforming is performed at elevated
temperatures and pressures, and a steam reformer typically includes a heating assembly
that provides heat for the steam reforming reaction. Illustrative but not exclusive uses of
the heat include maintaining the reforming catalyst bed at a selected refonning
temperature, or temperature range, and vaporizing a liquid feed stream prior to its use to
produce hydrogen gas. One type of heating assembly is a burner, in which a combustible
fuel stream is combusted with air. In a hydrogen-producing fuel processing assembly that
utilizes an autotliemial lefonner, or autothermal reforming region, hydrogen gas is
produced from a feed stream that includes a carbon-containing feedstock and water,

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which is reacted in the presence of air. Steam and autothermal reformers utilize
reforming catalysts tliat are adapted to produce hydrogen gas from tlie above-discussed
feed streams when tlie hydrogen-producing region is at a suitable hydrogen-producing
temperature, or within a suitable hydrogen-producing temperature range. The product
hydrogen stream from the hydrogen-producing region may be purified, if needed, and
thereafter used as a fuel stream for a fuel cell slack, which produces an electric current
from the product hydrogen stream and an oxidant, such as air. This electric current, or
power output, from the fuel cell stack may be utilized to satisfy the energy demands of an
energy-consuming device.
A consideration with any hydrogen-producing fuel cell system is the time it takes
to begin generating an electric current from hydrogen gas produced by the fuel cell
system after there is a need to begin doing so. In some applications, it may be acceptable
to have a period of time in which there is a demand, or desire, to have tlie fuel cell system
produce a power output to satisfy an applied load, but in which the system is not able to
produce the power output. In other applications, it is not acceptable to have a period
where the applied load from an energy-consuming device cannot be satisfied by the fuel
cell system even though there is a desire to have this load satisfied by the system. As an
illustrative example, some fuel cell systems are utilized to provide backup, or
supplemental power, to an electrical grid or other primary power source. When the
primary power source is not able to satisfy the applied load thereto, it is often desirable
for the backup fiiel cell system to be able to provide essentially instantaneous power so
that the supply of power to the energy-consuming devices is not interrupted, or not
noticeably interrupted.
Fuel cells typically can begin generating an electric current within a very short
amount of time after hydrogen gas or anotlier suitable fuel and an oxidant, such as air, is
delivered thereto. For example, a fuel cell stack may be adapted to produce an electric
current within less than a second after the flows of hydrogen gas and air are delivered to
the fuel cells in the fijel ceil stack. Inclusive of the time required to initiate the delivery of
these streams from a source containing the hydrogen gas and air, the time required to
produce the electric current should still be relatively short, such as less than a minute.
However, hydrogen-producing fuel cell systems that require the hydrogen gas to first be
produced, and perhaps purified, prior to being utilized to generate the desired power
output take longer to generate this power output. When the fuel processing assembly is
already at a suitable hydrogen-producing temperature, the fuel cell system may be able to

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produce the desired power output from hydrogen gas generated by the fuel processing
assembly witliin a few minutes, or less. However, v/hen the hydrogen-producing fuel
processor of tlie fuel cell system's fuel processbg assembly is not already at a desired
hydrogen-producing temperature, the required time will be much longer. For example,
when started up from an ambient temperature of 25° C, it may take thirty minutes or more
to properly start up the fuel processing assembly and to produce the desired power output
from hydrogen gas produced by the fuel processing assembly.
Conventionally, several dijfferent approaches have been taken to provide
hydrogen-producing fliel cell systems that can satisfy an applied load while the associated
hydrogen-producing &el processing assembly is started up from its off, or unheated and
inactive, operating state, heated to a suitable hydrogen-producing temperature, and
thereafter utilized to produce and optionally purify the required hydrogen gas to produce a
power output to satisfy the applied load. One approach is to include one or more batteries
or other suitable energy storage devices that may be used to satisfy the applied load until
the fuel cell system can produce a sufficient power output to satisfy the applied load.
Typically, this approach also requires that the fuel cell system include suitable chargers to
recharge the batteries during operation of the fuel cell system. This approach is effective,
especially for lower power demands of 1 kW or less, so long as the wei^t and size
requirements of the battery, or batteries, is acceptable. In portable fuel cell systems and
fuel cell systems that are designed to satisfy greater applied loads, such as loads of 10 kW
or more, it may not be practical to utilize batteries to satisfy an applied load for the time
required for the fuel processing assembly to be started up. Another approach is for the
fuel processing assembly to include a hydrogen storage device that is sized and otherwise
configured to store a sufficient amount of hydrogen gas to supply the fuel cell stack while
the fuel processing assembly is started up. Tj^ically, this approach also requires that the
fuel cell system include suitable compressors and other control and regulation structure to
recharge the storage device. This approach is also effective, but requires that tlie space,
additional equipment and expense of including the storage device and associated
components is acceptable.
In some applications, it may be desirable to be able to produce a desired power
output from hydrogen gas produced by the fiiel processing assembly of a hydrogen-
producing fuel cell system without requiring either stored hydrogen or stored power to be
used to satisfy the applied load wliile tlie fuel processing assembly is started up from' an
inactive, or off, operating state and heated to a suitable hydrogen-producing temperature.

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Summary of the Disclosure
The present disclosure is directed to thermally primed fuel processing assemblies
and to hydrogen-producing fuel cell systems that include the same. The thermally primed
fuel processing assemblies include at least one hydrogen-producing region, such as may
be adapted to produce hydrogen gas by a steam reforming or autothermal reforming
process utilizing a suitable refonning catalyst. At least the hydrogen-producing region is
housed witliin an internal compartment of a heated containment structure. In some
embodiments, the containment structure may be a heated and insulated containment
structure, hi some embodiments, the heated containment' structure is an oven. In some
embodiments, at least one purification region and/'or heating assembly is contained within
the internal compartment with the hydrogen-producing region. In some embodiments, the
containment structure is adapted to heat and maintain the internal compartment at or
above a threshold temperature, or within a selected temperature range, which in some
embodiments may correspond to a suitable hydrogen-producing temperature or
temperature range for the hydrogen-producing region. In some embodiments, the
containnent structure is adapted to maintain tlie internal compartment at this temperature,
or temj)erature range, during periods in which the fuel cell system is not producing a
power Dutput and/or not producing a power output to satisfy an applied load to the
system. In some embodiments, the fuel cell sj'stem is adapted to provide backup, or
supplemental, power to a primary power source that is adapted to provide power to at
least one energy-consuming device, and in some embodiments, the primary power source
is fiirthur adapted to provide power to the containment structure.

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Brief Description of tlie Drawings
Fig. 1 is a schematic view of a thermally primed hydrogen-producing fiiel cell
system according to the present disclosure.
Fig. 2 is a schematic view of a thermally primed Iiydrogen-producing fuel
processing assembly according to the present disclosure.
Fig. 3 is a fragmentary schematic view of another thermally primed hydrogen-
producing fuel processing assembly according to the present disclosure.
Fig. 4 is a fragmentary schematic view of anotlier thermally primed hydrogen-
producing fuel processing assembly according to the present disclosure.
Fig. 5 is a schematic view of portions of another thermally primed hydrogen-
producing fliel processing assembly according to the present disclosure
Fig. 6 is a schematic view of another thermally primed hydrogen-producing fuel
processing assembly according to the present disclosure.
Fig. 7 is a schematic view of a thermally primed hydrogen-producing fuel cell
system according to the present disclosure.
Fig. 8 is a schematic view of a thermally primed hydrogen-producing fuel cell
system according to the present disclosure, as well as an energy-consuming device and a
primary power source that is normally adapted to provide power to the energj'-consuming
device.
Detailed Description and Best Mode of the Disclosure
A thermally primed fuel processing assembly is shown in Fig. 1 and is indicated
generally at 10. Thermally primed fuel processing assembly 10 includes a thermally
primed fuel processor 12 that is adapted to produce a product hydrogen stream 14
containing hydrogen gas, and preferably at least substantially pure hydrogen gas, from
one or more feed streams 16. Feed stream 16 includes at least one carbon-containing
feedstock 18, and may include water 17. Fuel processor 12 is any suitable device, or
combination of devices, that is adapted to produce hydrogen gas from feed stream(s) 16.
Accordingly, fuel processor 12 includes a hydrogen-producing region 19, in which a
hydrogen gas is produced using any suitable hydrogen-producing mechanism(s) and/or
process(es). The product hydrogen stream may be delivered to a fuel cell stack 40, which
is adapted to produce an electric current, or power output, 41 from hydrogen gas and an
oxidant, such as air. An air stream is illustrated at 43 in Fig. 1 and may be delivered to
the fuel cells in the stacic via any suitable mechanism"or process. Systems according to
the present disclosure that include at least one fuel cell stack and at least one thermally

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primed fuel processing assembly that is adapted to produce hydrogen gas for tlie at least
one fuel cell stack may be referred to as thermally primed hydrogen-producing fuel cell
systems. Altliough a single fuel processor 12 and/or a single fuel cell stack 40 are shown
in Fig. 1, it is within the scope of the disclosure that more tlian one of either or botli of
these components, and/or subcomponents thereof, may be used.
Thermally primed fuel processing assembly 10 includes a hydrogen-producing
region 19 that is housed within a heated containment structure, or heated containment
assembly, 70 and which is adapted to produce hydrogen gas from the one or more feed
streams by utilizing any suitable hydrogen-producing mechanism(s). As discussed in
more detail herein, containment structure 70 defines an internal compartment 72 into
which at least the hydrogen-producing region of the fuel processing assembly is located.
The containment structure includes a heating assembly that is adapted to heat and
maintain tlie internal compartment, and structures contained therewithin, to a threshold
temperature, or temperature range. This threshold temperature, or temperature range may
correspond to a suitable hydrogen-producing temperature, or temperature range, for the
fiiel processing assembly to produce hydrogen gas in its hydrogen-producing region. The
containment structure may also be referred to as a heated containment system, and/or a
positively heated thermal reservoir that contains at least the hydrogen-producing region of
the fijel processing assembly.
Feed stream(s) 16 may be delivered to the hydrogen-producing region of
thermally primed fuel processor 12 via any suitable mechanism. While a single feed
stream 16 is shown in solid lines in Fig. 1, it is within the scope of the disclosure that
more than one stream 16 may be used and that these streams may contain the same or
different feedstocks. This is schematically illustrated by the inclusion of a second feed
stream 16 in dashed lines in Fig. 1. When feed stream 16 contains two or more
components, such as a carbon-containing feedstock and water, the components may be
delivered in the same or different feed streams. For example, when the fuel processor is
adapted to produce hydrogen gas from a carbon-containing feedstock and water, these
components are tjpically delivered in separate streams, and optionally (at least until both
streams are vaporized or otherwise gaseous), when they are not miscible with each other,
such as sho%vn in Fig. 1 by reference numerals 17 and 18 pointing to different feed
streams. When the carbon-containing feedstock is miscible with water, the feedstock is
typically, but is iiut required to be, delivered with the water component of feed stream 16,
such as shown in Fig. 1 by reference numerals 17 and 18 pointing to the same feed stream

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16. For example, when the fuel processor receives a feed stream containing water and a
water-soluble alcohol, such as methanol, these components may be premixed and
delivered as a single stream.
In Fig. 1, feed stream 16 is shown being delivered to fuel processor 12 by a
feedstock delivery system 22, which schematically represents any suitable mechanism,
device or combination thereof for selectively delivering the feed stream to the fuel
processor. For example, the delivery system may include one or more pumps that are
adapted to deliver the components of stream 16 fi-om one or more supplies. Additionally,
or alternatively, feedstock delivery system 22 may include a valve assembly adapted to
regulate the flow of the components from a pressurized supply. The supplies may be
located external of tlie fuel processing assembly, or may be contained within or adjacent
the assembly. When feed stream 16 is delivered to the fuel processor in more than one
stream, the streams may be delivered by the same or separate feedstock delivery systems.
Hydrogen-producing region 19 may utilize any suitable process or mechanism to
produce hydrogen gas from feed stream(s) 16. The output stream 20 from the hydrogen-
producing region contains hydrogen gas as a majority component. Output stream 20 may
include one or more additional gaseous components, and thereby may be referred to as a
mixed gas stream that contains hydrogen gas as its majority component. As discussed,
examples of suitable mechanisms for producing hydrogen gas from feed stream(s) 16
include steam reforming and autothermal reforming, in which reforming catalysts are
used to produce hydrogen gas from a feed stream 16 containing a carbon-containing
feedstock 18 and water 17. Examples of suitable carbon-containing feedstocks 18 include
at least one hydrocarbon or alcohol. Examples of suitable hydrocarbons include methane,
propane, natural gas, diesel, kerosene, gasoline and the like. Examples of suitable
alcohols include methanol, ethanol, and polyols. such as ethylene glycol and propylene
glycol.
Steam reforming is one example of a hydrogen-producing mechanism that may be
employed in hydrogen-producing region 19 in which feed sfream 16 comprises water and
a carbon-containing feedstock. In a steam reformmg process, hydrogen-producing
region 19 contains a suitable steam reforming catalyst 23, as indicated in dashed lines in
Fig. 1. In such an embodiment, the fuel processor may be referred to as a steam reformer,
hydrogen-producing region 19 may be referred to as a reforming region, and output, or
- mixed gas, stream 20 may be referred to as a refomiate stieain. As used herein, reforming
region 19 refers to any hydrogen-producing region utilizing a steam reforming hydrogen-

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producing mechanism. Examples of suitable steam reforming catalysts include copper-
zinc formulations of low temperature shift catalysts and a cliromium fonnulation sold
under the trade name KMA by Siid-Chemie, although others may be used. Tlie other
gases that may be present in the refonnate stream include carbon monoxide, carbon
dioxide, methane, steam, and/or unreacted carbon-containing feedstock.
Steam reformers tj'pically operate at temperatures in the range of 200° C and
900° C, and at pressures in the range of 50 psi and 300 psi, although temperatures and
pressures outside of this range are within the scope of the disclosure. When the carbon-
containing feedstock is methanol, the hydrogen-producing steam reforming reaction will
typically operate in a temperature range of approximately 200-500° C. Illustrative subsets
of this range include 350-450° C, 375-425° C, and 375-400° C. When the carbon-
containing feedstock is a hydrocarbon, ethanol, or a similar alcohol, a temperature range
of approximately 400-900° C will typically be used for the steam reforming reaction.
Illustrative subsets of this range include 750-850° C, 725-825° C, 650-750° C,
700-800° C, 700-900° C, 500-800° C, 400-600° C, and 600-800° C. It is within the scope
of the present disclosure for the hydrogen-producing region to include two or more zones,
or portions, each of which may be operated at the same or at different temperatures. For
example, when the hydrogen-production fluid includes a hydrocarbon, in some
embodiments it may be desirable to include two different hydrogen-producing portions,
with one operating at a lower temperature than the other to provide a pre-reforming
region. In such an embodiment, the fuel processing system may alternatively be
described as including two or more hydrogen-producing regions. Feed stream 16 is
typically delivered to reforming region 19 of fuel processor 12 at a selected pressure, such
as a pressure within the illustrative pressure range presented above. Thermally primed
fuel processing assemblies according to the present disclosure may therefore be adapted
to maintain at least the hydrogen-producing region of the fuel processor at or above a
threshold hydrogen-producing temperature tliat corresponds to one of the above-presented
illustrative temperatures, and/or within a selected threshold temperature range that
corresponds to one of the above-presented illustrative temperature ranges.
Another suitable process for producing hydrogen gas in the hydrogen-producing
region 19 of thermally primed fuel processor 12 is autothermal reforming, in which a
suitable autothermal reforming catalyst is used to produce hydrogen gas from water and a
carbon-containing feedstock in the presence of air. When autothermal reforming is used,
the thermally primed fuel processor flirther includes an air delivery assembly 68 that is

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adapted to deliver an air stream to the hydrogen-producing region, as indicated in dashed
lines in Fig. 1. Thermally primed fliel processing assemblies may be adapted to maintain
hydrogen-producing regions that utilize an autothermal reforming reaction at one of the
above-presented illustrative temperatures, or temperature ranges, discussed with respect
to hydrogen-producing steam reforming reactions. Autotliermal hydrogen-producing
reactions utilize a primary endothermic reaction that is utilized in conjunction with an
exothermic partial oxidation reaction tlmt generates heat within the hydrogen-producing
region upon initiation of the initial hydrogen-producing reaction. Accordingly, even
though autothermal hydrogen-producing reactions include an exothermic reaction, a need
still exists to initially heat the hydrogen-producing region to at least a minimum suitable
hydrogen-producing temperature.
The product hydrogen stream 14 produced by the fuel processing assembly may
be delivered to a fuel cell stack 40. A fuel cell stack is a device that produces an
electrical potential from a source of protons, such as hydrogen gas, and an oxidant, such
as oxygen gas. Accordingly, a fuel cell stack may be adapted to receive at least a portion
of product hydrogen stream 14 and a stream of oxygen (which is tj'pically delivered as an
air stream), and to produce an electric current therefrom. This is schematically illustrated
in Fig. 1, in which a fuel cell stack is indicated at 40 and produces an electric current, or
power output, which is schematically illustrated at 41. Fuel cell stack 40 contains at least
one, and typically multiple, fuel cells 44 that are adapted to produce an electric current
fit>m an oxidant, such as air, oxygen-enriched air, or oxygen gas, and the portion of the
product hydrogen stream 14 delivered thereto. The fiiei cells typically are joined together
between common end plates 48, which contain fluid delivery/removal conduits, although
this construction is not required to all embodiments. Examples of suitable fiiel cells
include proton exchange membrane (PEM) fuel cells and alkaline fuel cells. Others
include solid oxide fiiel cells, phosphoric acid fuel cells, and molten carbonate fuel cells.
The electric current, or power output, 41 produced by stack 40 may be used to
satisfy the energy demands, or applied load, of at least one associated energy-consuming
device 46. Illustrative examples of devices 46 include, but should not be limited to, tools,
lights or lighting assemblies, appliances (such as household or other appliances),
households or other dwellings, offices or other commercial establishments, computers,
signaling or communication equipment, etc. Similarly, fuel cell stack 40 may be used to
satisfy^tiie-powei requirements of fuel cell system 42, which may be referred to as the'
balance-of-plant power requu-ements of the fuel cell system. It should be understood that

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device 46 is schematically illustrated in Fig. 1 and is meant to represent one or more
devices, or collection of devices, that are adapted to draw electric cun-ent from, or apply a
load to, the fuel cell system.
As discussed, heated containment structure 70 is adapted to heat and maintain at
least the hydrogen-producing region of the thermally primed fuel processor at a suitable
hydrogen-producing temperature, such as at one of tlie illustrative temperatures discussed
above and/or +/- 25° C of these illustrative temperatures. An illustrative example of a
suitable containment structure 70 is schematically illustrated hi Fig. 2. As shown, the
containment structure defines an enclosure 84 containing internal compartment 72, which
is sized to receive, or house, at least the hydrogen-producing region of fuel processor 12.
The enclosure includes walls 86, which preferably include internal surfaces 88 that define
an at least substantially, if not completely, closed boundary around the internal
compartment. It is within the scope of the present disclosure that walls 86 may have the
same or different thicknesses, sizes, shapes, and the like. Similarly, it is not required that
the enclosure have a rectilinear configuration, with Fig. 2 merely intended to provide an
illustrative schematic example.
The walls and/or other portions of enclosure 86 preferably are insulated to reduce
the thermal load, or energy demand, to heat and maintain the internal compartment at the
selected temperature. Although not required, it is within the scope of the present
disclosure that the enclosure, such as walls 86, is/are sufficiently insulated that the
exterior surface 90 thereof is maintained at or below a threshold external temperature
while the internal compartment is maintained at one of the suitable threshold hydrogen-
producing temperatures discussed herein. Illustrative, non-exclusive examples of suitable
threshold external temperatures include temperatures of less than 100° C, thresholds of
less than 75° C, less than 50° C, and less than 25° C. As discussed, these external
temperatures are not required, and the exterior of the enclosure may be at temperatures
that exceed these illustrative examples without departing from the scope of the present
disclosure.
It is within the scope of the present disclosure that the enclosure 84 may include
one or more vents or other air-circulation passages. It is also within the scope of the
present disclosure that the only fluid passages between the internal compartment and
exterior of the enclosure is through defined inlet and outlet conduits, or ports, such as to
deliver feed stream(s) to tlie hydrogen-producing region, to withdraw the hydrogen-
containing stream(s) from the enclosure, and/or to deliver air to into the compartment and

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to withdraw exhaust from tlie enclosure. This is somewhat schematically illustrated in
Fig. 2, in which a feed stream port is indicated at 92, a product hydrogen port is indicated
at 94, an air inlet port is indicated at 96, and an exhaust port is indicated at 98. More than
one of the illustrated examples of possible ports may be mcluded in any containment
structure according to the present disclosure. Similarly, the structure may include one or
more ports in addition to, or instead of, one or more of the illustrative ports described
above.
\Vhen the fluid streams that are delivered into or withdrawn from a particular
structure within the internal compartment, such as instead of the internal compartment
generally, the ports may be associated with one or more fluid conduits 100 that define
prescribed flow paths for the fluids within the compartment. For example, feed port 92
includes a fluid conduit that delivers the feed stream to the hydrogen-producing region.
This conduit may define or otherwise form at least a portion of a vaporization region 102,
in which a feed stream that is delivered as a liquid stream is vaporized prior to being
delivered into contact with the reforming catalyst in hydrogen-producing region 19. In
some embodiments, the vaporization region may be contained within the hydrogen-
producing region, with the feed stream being \'aporized prior to being delivered into
contact with the reforming catalyst. In some embodiments, the feed stream may be a
gaseous stream when introduced into the internal compartment and therefore may not
need to be vaporized in a vaporization region within the compartment. Also shown in the
illustrative example shown in Fig. 2 is a conduit 100 through which the hydrogen gas
from the hydrogen-producing region is delivered to hydrogen port 94, which is in fluid
communication with the fuel cell stack..
Fig. 2 also illustrates that heated containment structures 70 according to the
present disclosure also include, or optionally are in thermal communication with, a
heating assembly 110 that is adapted to heat die internal compartment to at least a
threshold temperature, such as a suitable hydrogen-producing temperature, during periods
in which the hydrogen-producing region is not producing hydrogen gas but in which it is
desirable to maintain the hydrogen-producing region in a primed operating state. As
discussed, this primed, or thermally primed, operating state may be an operating state in
which at least the hydrogen-producing region is maintained at, or within, a suitable
hydrogen-producing temperature or range of temperatures. It is within the scope of the
present disclosure that heating assembly 110 may be configured to only heat the internal
compartment (and its contents) when the hydrogen-producing region is not producing

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hydrogen gas. However, it is also within the scope of the present disclosure that the
heating assembly may be configured to heat the internal compartment (and its contents)
until the hydrogen-producing region begins producing hydrogen gas and/or until the fuel
cell stack begins producing a sufficient power output to satisfy the applied load to the fuel
cell system. As a further illustrative example, the heating assembly may be configured to
continue heating the internal compartment and its contents for a selected time period after
the above-discussed events occur (or are detected). As still a further example, the heating
assembly may be adapted to continue to provide heat to the internal compartment (and its
contents) regardless of whether the hydrogen-producing region is producing hydrogen gas
and/or the fuel cell stack is producing an electric current, such as if the internal
compartinent, or a selected region thereof, falls below the threshold temperature (or falls
below this temperature by more than a selected temperature range).
As illustrated in the schematic example shown in Fig. 2, the containment structure
includes a heating assembly 110 that is adapted to heat the internal compartment 72 of the
containment structure, and accordingly, to heat the hydrogen-producing region and any
other structure contained in the internal compartment to the selected threshold
temperature. In solid lines in Fig. 2, heating assembly 110 is illustrated being located
within enclosure 84 and external of the internal compartment 72 of the containment
structure. As discussed, this configuration is not required and it is within the scope of the
present disclosure that the heating assembly may be partially or completely positioned
external of enclosure 84 and/or within internal compartment 72, as schematically
represented in dashed lines in Fig. 2.
A suitable structure for heating assembly 110 is an electrically powered
heater 112, such as resistance heater that is powered by a suitable power source, such as a
battery, an electrical grid, a generator, or any other suitable power source adapted to
provide electrical power to the heater. Heater 112 may, but is not required to, generate a
heating fluid stream 116 that is delivered into tlie internal compartment, such as when the
heater receives an air stream 118 that is heated and delivered into the internal
compartment. Heater 112 and/or any other suitable heating assembly 110 may include
one or more heating elements, or heat sources, 114 that may be positioned in any suitable
location relative to the internal compartment of the containment structure. For example,
the heating assembly may include at least one heating element that is within, or which
extends at least partially within, the internal compartment. Additionally or alternatively.

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the heating assembly may include one or more compartments that extend completely, or
at least partially, within one or more walls 86 of tlie containment structure.
As a further illustrative, non-exclusive example, heating assembly 110 may
include a combustion region 120 that generates a heating fluid stream 116 in the form of a
combustion exhaust stream that may be delivered to the intemal compartment to heat the
compartment and structures contained herein. The combustion region may be within the
containment structure, within the internal compartment, or may be external the
containment structure. In at least this latter example, the combustion exhaust stream may
be delivered to the intemal compartment through one or more fluid conduits, such as may
extend through at least one wall of the containment stiicture to deliver the combustion
exhaust stream into the intemal compartment.
Fig. 3 illustrates an example of a containment structure 70 that includes, or is in
thermal communication with, a heating assembly 110 that includes an electrically
powered heater 112. As shown, heater 112 is in electrical communication with a power
source 130 that is adapted to provide sufficient power to the heater to enable the heater to
heat the intemal compartment to tlie selected threshold temperature and to thereafter
maintain this temperature and/or a suitable temperature range of the selected threshold
temperature, such as ± 5°C, ± 10° C, or ± 25° C of this temperature. The heating
element(s) 114 of the electrical heater may extend in any suitable position relative to the
intemal compartment. Illustrative, non-exclusive examples of which include positions
along or within one or more of the walls 86 of the enclosure and/or within intemal
compartment 72. As illustrated in dashed lines in Fig. 3, the electrical heater may receive
an air stream 118, with the heater heating this stream to produce a heating fluid stream
that is delivered into the intemal compartment to heat at least the hydrogen-producing
region of the thermally primed fuel processing assembly'.
Fig. 4 illustrates an example of a containment stmcture 70 that includes, or is in
thermal communication witli, a heating assembly 110 that includes a combustion region
120 that is adapted to receive and combust a combustible fuel stream 122 in the presence
of air, such as from an air stream 118, to produce a heating fluid stream 116 in the form
of a combustion exhaust stream. Fuel stream 122 may include any suitable combustible
fuel, with illustrative examples including gaseous and liquid ftiels. Further illustrative
examples include feed stream 16, carbon-containing feedstock 18, hydrogen or other
gases produced by the hydrogen-producing itgiou, pixjpane, natuitil gas, gasoline,
kerosene, diesel, and the like. The combustion region may be adapted to receive and

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combust a particular fuel or type of fuel. The combustion region may include an igniter,
or other suitable ignition source, 124 that is adapted to initiate combustion of the fuel
stream, with it being within the scope of the present disclosure that the igniter is in
electrical communication with a power source 130 that is adapted to selectively actuate
the igniter. In addition to the previously discussed examples of suitable power sources,
the igniter may be adapted to be powered by a flywheel or ultracapacitor.
As discussed above with respect to Fig. 2, heating assemblies may be positioned
external, within, and/or internal of the enclosure that defines the internal compartment of
tlie containment structure. Accordingly, the illustrative examples of electrical heaters and
combustion regions shown in Figs. 3 and 4 may be implemented at least partially, if not
completely, external of the enclosure, within the enclosure, or within the internal
compartment. As also discussed, at least when it is located external of the enclosure, the
heating assembly may include at least one fluid conduit to selectively deliver a heating
fluid stream to the internal compartment or otherwise into thermal communication with
the internal compartment to provide the desired heating of the compartment and its
contents. It is further witliin the scope of the present disclosure that the internal
compartment may include one or more subcompartments, may include one or more heat
deflection structures, thermal baffles or barriers, fans or circulation members, and/or other
temperature-modulating structures that selectively define regions of higher and lower
temperatures within the internal compartment. These optional temperature-modulating
structures are schematically illustrated, individually and in combination, in Fig. 2 at 134.
In Figs. 1-4, thermally primed fuel processing assembly 10 has been described as
including at least a hydrogen-producing region 19 tliat is positioned within the internal
compartment of a heated containment structure 70 according to the present disclosure. In
each of these Figures, reference numeral 136 is also presented in dashed lines to indicate
that other components of the fuel processing assembly may be located within the internal
compartment and therefore heated and maintained at a selected threshold temperature
and/or within a selected temperature range by heating assembly 110. When present in the
internal compartment, these components of the fuel processing assembly should be
configured to withstand the temperature that is' maintained within the compartment by
heating assembly 110. An example of an additional component of the thermally primed
fuel processing that, when present, may be (but is not required to be) housed within
compartment" 72 is a vaporization region, such as schematically illustrated in Fig. 2
at 102. It is within the scope of the present disclosure that vaporization region 102, when

WO 2007/037856 PCT/US2006/033027
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present, may be otlierwise configured and may, in some embodiments, be located within a
common shell, or housing, with the hydrogen-producing region in the internal
compartment. In Fig. 2, the shell, or housing, tliat contains the hydrogen-producing
region within the internal compartment is indicated at 104,
Another example of a component of fuel processing assembly 10 that may (but is
not required to) be present in internal compartment 72 is a heating assembly 140 that is
adapted to heat at least the hydrogen-producing region when the hydrogen-producing
region is in a hydrogen-producing operating state. An illustrative example of such a
heating assembly is indicated schematically in Fig. 5. Heating assembly 140 may be
referred to as a second, or secondary, or active operating state heating assembly. WHien
present in a particular embodiment of assembly 10, the hydrogen-producing heating
assembly is adapted to combust a fuel stream 142 to generate a combustion stream 144 to
maintain at least the hydrogen-producing region 19 of fiiel processing assembly 10 at a
suitable hydrogen-producing temperature or range of temperatures. In some
embodiments, this secondary heating assembly may be referred to as a burner. In some
embodiments, the secondary heating assembly may be adapted to additionally or
alternatively heat other portions of the fuel processing assembly, such as a membrane
module or other purification region, catalyst region, etc. Heating assembly 140 may
utilize air that is delivered by air stream 118 to support combustion, and may utilize an
igniter or other suitable ignition source, such as discussed previously with respect to
combustion region 120. Fuel stream 142 may include any suitable combustible fuel. As
discussed, illustrative examples include various gaseous fuels, such as various
combustible gaseous streams produced by the fuel processing assembly, gaseous carbon-
containing feedstocks, liquid carbon-containing feedstocks, and combustible fuel streains
containing any of these components. While not required to all embodiments, it is within
the scope of the present disclosure that the fuel stream may include, or even be
completely formed fixim, at least a portion of output stream 20. It is further which the
scope of the present disclosure that this gaseous fuel stream may be supplemented with
additional fuel that is delivered to the heating assembly from external the compartment,
such as via a suitable port.
It is within the scope of the present disclosure that the hydrogen-producing region
may utilize a process that inherently produces sufficiently pure hydrogen gas for use as a
fuel stream for fuel ceU stack 40. WTien the output stream contains sufficiently pure'
hydrogen gas and/or sufficiently low concentrations of one or more non-hydrogen

WO 2007/037856 PCT/US2006/033027
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components for use as the fuel stream for fiiel cell stack 40, product hydrogen stream 14
may be formed directly from output stream 20. However, in many hydrogen-producing
processes, output stream 20 will be a mixed gas stream that contains hydrogen gas as a
majority component along with other gases. Similarly, in many applications, tlie output
stream 20 may be substantially pure hydrogen gas but still contain concentrations of one
or more non-hydrogen components that are harmful or otherwise undesirable in the
application for which the product hydrogen stream is intended to be used.
For example, when stream 14 is intended for use as a fuel stream for a fiiel cell
stack, such as stack 40, compositions that may damage the fuel cell stack, such as carbon
monoxide and carbon dioxide, may be removed from the hydrogen-rich stream, if
necessary. For many fuel cell stacks, such as proton exchange membrane (PEM) and
alkaline fuel cell stacks, the concentration of carbon monoxide is preferably less than
10 ppm (parts per million). Preferably, the concentration of carbon monoxide is less than
5 ppm, and even more preferably, less than 1 ppm. The concentration of carbon dioxide
may be greater than that of carbon monoxide. For example, concentrations of less than
25% carbon dioxide may be acceptable in some embodiments. Preferably, the
concentration is less tlian 10%, and even more preferably, less than 1%. While not
required, especially preferred concentrations are less than 50 ppm. The acceptable
minimum concentrations presented herein are illustrative examples, and concentrations
other than those presented herein may be used and ai-e within the scope of the present
disclosure. For example, particular users or manufecturers may require minimum or
maximum concentration levels or ranges that are different than those identified herein.
Accordingly, thermally primed fuel processing assembly 10 may (but is not
required to) further include a purification region 24, in which a hydrogen-rich stream 26
is produced fix>m the output, or mixed gas, stream from hydrogen-producing region 19.
Hydrogen-rich stream 26 contains at least one of a greater hydrogen concentration than
output stream 20 and a reduced concentration of one or more of the other gases or
impurities that were present in the output stream. In Fig. 6, the illustrative example of a
thermally primed fiiel processing assembly shown in Fig. 2 is shown including at least
one purification region 24. Purification region 24 is schematically illustrated in Fig. 6,
where output, or mixed gas, stream 20 is shown being delivered to an optional
purification region 24. As shown in Fig. 6, ai least a portion of hydrogen-rich stream 26
forms product hydrogen stream 14. Accordingly, hydrogen-rich stream 26 and product
hydrogen stream 14 may be the same stream and have the same compositions and flow

WO 2007/037856 PCT/US2006/033027
17
rates. However, it is also within the scope of the present disclosure that some of the
purified hydrogen gas in hydrogen-rich stream 26 may be stored for later use, such as in a
suitable hydrogen storage assembly, and/or consumed by the fuel processing assembly.
Purification region 24 may, but is not required to, produce at least one byproduct
stream 28. When present, byproduct stream 28 may be exhausted, sent to a burner
assembly or other combustion source (such as a hydrogen-producing heating assembly),
used as a heated fluid stream, stored for later use, or otherwise utilized, stored or disposed
of. It is within the scope of the disclosure that bj'product stream 28 may be emitted from
the purification region as a continuous stream responsive to the delivery of output stream
20 to the purification region, or intermittently, such as in a batch process or when the
byproduct portion of the output stream is retained at least tempomrily in the purification
region.
Purification region 24 includes any suitable device, or combination of devices,
that ai-e adapted to reduce the concentration of at least one component of output
stream 20. In most applications, hydrogen-rich stream 26 will have a greater hydrogen
concentration than output, or mixed gas, stream 20. However, it is also within the scope
of the present disclosure that the hydrogen-rich stream will have a reduced concentration
of one or more non-hydrogen components that were present in output stream 20, yet have
the same, or even a reduced overall hydrogen concentration as the output stream. For
example, in some applications where product hydrogen stream 14 may be used, certain
impurities, or non-hydrogen components, are more harmful than others. As a specific
example, in conventional fuel cell systems, carbon monoxide may damage a fiiel cell
stack if it is present in even a few parts per million, while other non-hydrogen
components that may be present in stream 20, such as water, will not damage the stack
even if present in much greater concentrations. Therefore, in such an application, a
suitable purification region may not increase the overall hydrogen concentration, but it
will reduce the concentration of a non-hydrogen component that is harmful, or potentially
harmful, to the desired application for the product hydrogen stream.
Illustrative examples of suitable devices for purification region 24 include one or
more hydrogen-selective membranes 30, chemical carbon monoxide (or other impurity)
removal assemblies 32, and pressure swing adsorption systems 38. It is within the scope
of the disclosure that purification region 24 may include more than one type of
purification device, and that these devices may have tiie same or different structures
and/or operate by the same or different mechanisms.

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Hydrogen-selective membranes 30 are permeable to hydrogen gas, but are at least
substantially, if not completely, impermeable to other components of output stream 20.
Membranes 30 may be formed of any hydrogen-permeable material suitable for use in tlie
operating environment and parameters in which purification region 24 is operated.
Examples of suitable materials for membranes 30 include palladium and palladium alloys,
and especially thin films of such metals and metal alloys. Palladium alloys have proven
particulariy effective, especially palladium with 35 wt% to 45 wt% copper. A palladium-
copper alloy that contains approximately 40 wt% copper has proven particularly effective,
although other relative concentrations and components may be used within the scope of
the disclosure.
Hydrogen-selective membranes are typically formed fi-om a thin foil that is
approximately 0.001 inches thick. It is within tlie scope of the present disclosure,
however, tliat the membranes may be formed from other hydrogen-permeable and/or
hydrogen-selective materials, including metals and metal alloys other than those
discussed above as well as non-metallic materials and compositions, and that the
membranes may have thicknesses tliat are greater or less than discussed above. For
example, the membranes may be made thinner, with cominensurate increase in hydrogen
flux. Examples of suitable mechanisms for reducing the thickness of tlie membranes
include rolling, sputtering and etching. A suitable etching process is disclosed in U.S.
Patent No. 6,152,995, the complete disclosure of which is hereby incorporated by
reference for all purposes. Examples of various membranes, membrane configurations,
and methods for preparing the same are disclosed in U.S. Patent Nos. 6,221,117,
6,319,306, and 6,537,352, the complete disclosures of which are hereby incorporated by
reference for all purposes.
Chemical carbon monoxide removal assemblies 32 are devices that chemically
react carbon monoxide and/or other undesirable components of stream 20, if present in
output stream 20, to form other compositions that are not as potentially harmful.
Examples of chemical carbon monoxide removal assemblies include water-gas shift
reactors and other devices that convert carbon monoxide to carbon dioxide, and
methanation catalyst beds that convert carbon monoxide and hydrogen to methane and
water. It is within the scope of the disclosure that fuel processing assembly 10 may
include more than one type and/or number of chemical removal assemblies 32.
Pressure swing adsorption (PSA) is a chemical process in which gaseous
impurities are removed from output stream 20 based on the principle that certain gases,

WO 2007/037856 PCT/US2006/033027
19
under the proper conditions of temperature and pressure, will be adsorbed onto an
adsorbent material more strongly than other gases. Typically, it is tlie impurities that are
adsorbed and removed from output stream 20. The success of using PSA for hydrogen
purification is due to the relatively strong adsorption of common impurity gases (such as
CO, CO2, hydrocarbons including CH4, and No) on the adsorbent material. Hydrogen
adsorbs only very wealdy and so hydrogen passes through the adsorbent bed while the
impurities are retained on the adsorbent material. Impurity gases such as NH3, H2S, and
H2O adsorb very strongly on the adsorbent material and are removed from stream 20
along with other impurities. If the adsorbent material is going to be regenerated and these
impurities are present in stream 20, purification region 24 preferably includes a suitable
device that is adapted to remove these impurities prior to deliveiy of stream 20 to the
adsorbent material because it is more difficult to desorb these impurities.
Adsorption of impurity gases occurs at elevated pressure. When the pressure is
reduced, the impurities are desorbed from the adsorbent material, thus regenerating the
adsorbent material. Typically, PSA is a cyclic process and requires at least two beds for
continuous (as opposed to batch) operation. Examples of suitable adsorbent materials
that may be used in adsorbent beds are activated carbon and zeolites, especially 5 A
(5 angstrom) zeolites. The adsorbent material is commonly in the form of pellets and it is
placed in a cylindrical pressure vessel utilizing a conventional packed-bed configuration.
Other suitable adsorbent material compositions, forms, and configurations may be used.
PSA system 38 also provides an example of a device for use in purification
region 24 in which the byproducts, or removed components, are not directly exhausted
from the region as a gas stream concurrently with the purification of the output stream.
Instead, these byproduct components are removed when the adsorbent material is
regenerated or otherwise removed from the purification region.
In the illustrative, non-exclusive embodiment sliown in Fig. 6, purification region
24 is shown in solid lines within internal compartment 72 and as a separate structure from
the housing 104 that contains hydrogen-producing region 19. It is witliin the scope of the
disclosure that housing 104 may additionally or alternatively include a purification region
24 in addition to hydrogen-producing region 19, with the purification region(s) being
adapted to receive the mixed gas, or reformate, stream produced in the hydrogen-
producing region. It is also within the scope of the present disclosure that the fiiel
processing assembly may include a purification region 24 that is external of the
contaiimient structure's enclosure, such as indicated in dash-dot lines in Fig. 6. Any of

WO 2007/037856 PCT/US2006/033027
20
the thennally primed fuel processing assemblies described, illustrated and/or incorporated
herein may be, but are not required to be, implemented with one or more of the
purification regions described, illustrated, and'or incorporated herein.
In the context of a fuel processor, or fuel processmg assembly, that is adapted to
produce a product hydrogen stream that will be used as a feed, or fuel, stream for a fuel
cell stack, the fuel processor preferably is adapted to produce substantially pure hydrogen
gas, and even more preferably, the fuel processor is adapted to produce pure hydrogen
gas. For the purposes of the present disclosure, substantially pure hydrogen gas is greater
than 90% pure, preferably greater than 95% pure, more preferably greater than 99% pure,
and even more preferably greater than 99.5% pure. Suitable fuel processors for producing
streams of at least substantially pure hydrogen gas are disclosed in U.S. Patent Nos.
6,319,306, 6,221,117, 5,997,594, 5,861,137, pending U.S. Patent Application Serial No.
09/802,361, which was filed on March 8, 2001 and is entitled 'Tuel Processor and Systems
and Devices Containing the Same," and U.S. Patent Application Serial No. 10/407,500,
which was filed on April 4,2003, is entitled "Steam Reforming Fuel Processor," and which
claims priority to U.S. Provisional Patent Application Serial No. 60/372,258. The complete
disclosures of the above-identified patents and patent applications are hereby incorporated by
reference for all purposes.
Fig. 7 illustrates another example of a fuel cell system 42 that includes a
thennally primed fuel processing assembly 10 according to the present disclosure. Fig. 7
is intended to illustrate additional components that may, but are not required in all
embodiments, be included in system 42 and/or assembly 10. In other words, it is within
the scope of the present disclosure that thermally primed fliel processing assemblies and
fuel cell systems containing the same may include additional components besides those
described and/or illustrated herein, such as one or more suitable, controllers, flow
regulating devices, heat exchangers, heating/cooling assemblies, fuel/feed supplies,
hydrogen storage devices, energy storage devices, reservoirs, filters, and the like.
Fuel cell stack 40 may receive all of product hydrogen stream 14. Some or all of
stream 14 may additionally, or alternatively, be delivered, via a suitable conduit, for use
in another hydrogen-consuming process, burned for fuel or heat, or stored for later use.
As an illustrative example, a hydrogen storage device 50 is shown in Fig. 7. Device 50 is
adapted to store at least a portion of product hydrogen stream 14. For example, when the
demand for hydrogen gas by stack 40 is less than the hydrogen output of fiiel processor
12, the excess hydrogen gas may be stored in device 50. Illustrative examples of suitable

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21
hydrogen storage devices include hydride beds and pressurized tanlcs. Although not
required, a benefit of fuel processing assembly 10 or fuel cell system 42 including a
supply of stored hydrogen gas is that this supply may be used to satisfy the hydrogen
requirements of stack 40, or the other application for which stream 14 is used, in
situations when thennally primed fuel processor 12 is not able to meet these hydrogen
demands. Examples of these situations include when the fuel processor is offline for
maintenance or repair, and when the fuel cell stack or application is demanding a greater
flow rate of hydrogen gas than the maximum available production from the fuel
processor. Additionally or alternatively, the stored hydrogen may also be used as a
combustible fuel stream to heat the fuel processing assembly or fuel cell system. Fuel
processing assemblies that are not directly associated with a fuel cell stack may still
include at least one hydrogen storage device, thereby enabling the product hydrogen
streams from these fuel processing assemblies to also be stored for later use.
Thermally primed fiiel cell system 42 may also include a battery or other suitable
energy storage device 52 that is adapted to store the electric potential, or power output,
produced by stack 40 and to utilize this stored potential to provide a power source (such
as one or more of the previously described power sources 130). For example, device 52
may be adapted to provide power to one or more of an igniter, pump (such as to supply
feed stream 16), blower or other air propulsion device (such as to deliver air stream 118),
sensor, controller, flow-regulating valve, and the like. Device 52 may be a rechargeable
device, and fuel cell system 42 may include a charging assembly that is adapted to
recharge the device. It is also withm the scope of the present disclosure that device 52
may be present in system 42 but may not be adapted to be recharged by system 42.
Similar to the above discussion regarding excess hydi-ogen gas, fuel cell stack 40 may
produce a power output in excess of that necessary to satisfy the load exerted, or applied,
by device 46, including the load required to power fuel cell system 42. In flirther
similarity to the above discussion of excess hydrogen gas, this excess power output may
be used in other applications outside of the fuel cell system and/or stored for later use by
the fuel cell system. For example, the battery or other storage device may provide power
for use by system 42 during periods in which the system is not producing electricity
and/or hydrogen gas.
WTien fuel cell system 42 includes a hydrogen storage device 50, the hydrogen
storage device may be designed, sized, or otherwise adapted to not be able to satisfy the
hydrogen demands of the fuel cell stack duiing a time period that is equal to the time

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22
period in which it would take the fiiel cell system to start up from an unheated operating
state (i.e., if the system was implemented without a thermally primed fuel processing
assembly). This response time may be referred to as a start up response time, in that it
includes the time required to heat at least the hydrogen-producing region to a suitable
hydrogen-producing temperature. This start up response time is contrasted with tlie time
required to produce hydrogen gas from the thermally primed fuel processing assembly
that has been maintained at a suitable hydrogen-producing temperature, and then to
generate a power output therefrom. This response time may be referred to a thermally
biased response time.
Therefore, while not required, the fuel cell system may include a hydrogen
storage device that has insufficient capacity, even when fully charged, to provide
sufficient amounts of hydrogen gas to provide the hydrogen gas required by the fuel cell
stack to satisfy the applied load thereto during a time period that is equal to the time that
would otherwise be required to start up the fuel cell system from an off, or unheated,
operating state. As further illustrative examples, the maximum capacity of the hydrogen-
storage device may be selected to be less than 75%, less than 50% or even less then 25%
of this potential hydrogen demand. Expressed in slightly different terms, during a time
period that corresponds to the time it would take to start up the fuel cell stack from an
unheated operating state (i.e., if the thennally primed fuel processor assembly was not
present or operational), the fuel cell stack may require a volume of hydrogen gas to
generate a sufficient power output to satisfy the applied load thereto, with this volume
exceeding the capacity of the hydrogen storage device, and optionally exceeding the
capacity of the hydrogen storage device by at least 25%, 50%, 75%, or even 100% of its
capacity.
Similarly, when fuel cell system 42 includes an energy storage device 52, such as
a battery, capacitor or ultracapacitor, flywheel, or the like, this device may have a
maximum charge that is less tlian the power output that would be required to satisfy the
applied load to the fuel cell stack during a time period that corresponds to the time that
would be required to startup the fuel cell system from an unheated, off operating state
(i.e., if the thermally primed fuel processing assembly was not present). It is within the
scope of the present disclosure that this maximum charge may be less than tlie required
power output by at least 25%, 50%, 75%, or more. Expressed in slightly different terms,
during a time period that corresponds to the time it v^'ould take to start up the ftiel cell
stack fixDm an unheated (off and/or unprimed) operating state (i.e., if the thermally primed

WO 2007/037856 PCTAJS2006/033027
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fuel processing assembly was not present), the energy-consuming device may demand, or
require, a power output tiiat exceeds the maximum (i.e., fully charged) capacity of the
energy-storage device.
This intentional undersizing of devices 50 and/or 52 is not required, especially
since these components are not required to all embodiments. However, the above
discussion demonstrates that it is within the scope of the present disclosure to include a
hydrogen storage device and/or energy storage device while still requiring tlie heated
containment assembly for the system to be properly operational. A related consideration
is the cost and/or space required for these components if they were sized to provide a fuel
cell system that did not include a heated containment structure according to the present
disclosure.
In Fig. 7, optional flow-regulating structures are generally indicated at 54 and
schematically represent any suitable manifolds, valves, controllers, switches and the like
for selectively delivering hydrogen gas and the fuel cell stack's power output to device 50
and battery 52, respectively, and to draw the stored hydrogen and stored power output
therefrom. Also shown in Fig. 7 is an optional, and schematically illustrated, example of
a power management module 56 that is adapted to regulate the power output from the fuel
cell stack, such as to filter or otherwise normalize the power output, to convert the power
output to a higher or lower voltage, to convert the power output from a DC power output
to an AC power output, etc.
Thennally primed fuel processing assemblies, and fuel cell systems incorporating
the same, may also include or be in communication with a controller that is adapted to
selectively control the operation of the assembly/system by sending suitable command
signals and/or to monitor the operation of the assembly/system responsive to input from
various sensors. A controller is indicated in dash-dot lines at 58 in Fig. 7 as being in
communication with energy-storage device 52 (and/or power source 130) to indicate that
the controller may be adapted to be powered thereby. It is also within the scope of the
present disclosure that the controller, when present, is powered by another suitable power
source. The controller may be a computerized, or computer-implemented controller and
in some embodiments may include software and hardware components. The controller
may be a dedicated controller, in that it is primarily adapted to monitor and/or control the
operation of the fuel cell system or fuel processing assembly. It is also witliin the scope
of the present disclosure that the controller, when present, may be adapted to pertbnn
other functions.

WO 2007/037856 PCT/US2006/033027
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In Fig. 8, a thermally primed fuel cell system 42 (i.e., a fuel cell system that
includes a tliermally primed fuel processing assembly 10) according to the present
disclosure is shown being adapted to provide backup power to an energy-consuming
device 46 that is adapted to be powered by a primary power source 200. In other words,
when the primary power source is operational, it satisfies the load applied by energy-
consuming device 46. While primary power source 200 is operational and available to
satisfy the applied load from energy-consuming device 46, the heated containment
structure of thermally primed fuel processing assembly 10 may be operational to maintain
at least the hydrogen-producing region 19 of the fuel processor at a threshold hydrogen-
producing temperature range and/or within a threshold hydrogen-producing temperature
range, such as those described and/or incorporated herein. In such a configuration, fuel
cell system 42 is configured to provide backup, or supplemental, power to the energ}'-
consuming device, such as when the primary power source is not operational or is
otherwise not available or able to satisfy the applied load from the energy-consuming
device. In Fig. 8, only portions of system 42 are shown, and it is within the scope of the
present disclosure that system 42 may include any of the components, subcomponents,
and/or variants described, illustrated and/or incorporated herein.
When configured to provide backup power to an energy-consuming device 46,
system 42 may be configured to detect the operational state of the primary power source
via any suitable mechanism and/or may be adapted to initiate the production of hydrogen
gas (and thereby initiate the generation of power output 41) responsive to detecting an
applied load to the ftiel cell system from the energy-consuming device. When system 42
includes, or is in communication with a controller, the controller may include at least one
sensor that is adapted to detect whether a load is being applied to the thermally primed
hydrogen-producing fuel cell system from the energy-consuming device, and/or whether
the primary power source is providing any (or sufficient) power to the energy-consuming
device. Responsive at least in part to this detection, the controller may initiate the
production of hydrogen gas by sending one or more suitable command signals to the
feedstock delivery system to cause stream(s) 16 to be delivered to the hydrogen-
producing region of the fuel processing assembly. The controller may be adapted to
perform various diagnostics, or system integrity checks responsive to the detection that
system 42 is needed to provide a power output to satisfy an applied load fix>m the energy-
consuming device. As discussed, the controller may be a computerized, or computer-
implemented controller that is adapted to perform various control and/or monitoring

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25
functions and/or which may include hardware and software components, may include a
microprocessor, and/or may include a digital or analog circuit. The controller, when
present, may also simply include a sensor or detector that is adapted to send a command
signal to feedstock delivery system 22 responsive to detecting that there is a need for
system 42 to being producing a power output.
As indicated in Fig. 8, it is within the scope of the present disclosure that at least
the heating assembly 110 of, or associated with, the heated containment structure may be
adapted to be powered by the primary power source when the primary power source is
available to satisfy the applied load of the energj'-consuming device. Accordingly, when
the primary power source is operational, it may be configured to supply the applied load
of the energy-consuming device, while also providing power to at least the heating
assembly of the thermally primed fuel processing system of fuel cell system 42. In such a
configuration, the fuel cell system may be maintained in its "primed" operational state, in
which at least the hydrogen-producing region thereof is maintained at a suitable
temperature for producing hydrogen gas therein responsive to the delivery of a suitable
feed stream(s) thereto. However, because the power requirements of the fuel cell system
are satisfied by the primary power source while the primary power source is operational,
the fuel cell system does not need to generate a sufficient, or even any, power output
while in its primed operational state. Similarly, the fiiel processing assembly may not be
generating any hydrogen gas while in this operational state, even though it is being
maintained at a suitable temperature, or witliin a suitable temperature range, for
generating hydrogen gas.
When, and if, the primary power source fails, is offline, or otherwise is unable to
satisfy the applied load of the energy-consuming device, the thermally primed fuel cell
system is able to generate a power output to satisfy this applied load. Furthermore,
because the fuel processing assembly was maintained at a suitable temperature (or
temperature range) for generating hydrogen gas, the time required to begin generating the
required power output will be considerably less than if tlie fuel processing assembly was
instead maintained at an unheated, or off, operational state. For example, the thermally
primed fuel cell system may be able to satisfy the applied load in less then a few minutes,
such as less then three minutes, less than two minutes, less then one minute, or even less
than fortj'-five seconds, inclusive of any diagnostics or other self-checks performed by a
controller of the system. Expressed in sliglitly different terms, thermally biased
hydrogen-producing fuel cell systems may have a thermally biased response time to begin

WO 2007/037856 PCT/US2006/033027
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generating a power output from hydrogen gas produced in the system, with this response
time being less than a few minutes, less than two minutes, less than one minute, less than
forty-five seconds, etc. This response time will be much shorter than a comparative start
up response time if the hydrogen-producing fael cell system was not a thennally biased
hydrogen-producing fuel cell system.
As discussed above, thermally primed fuel cell systems according to the present
disclosure may include a hydrogen-storage device and/or an energy-storage device that is
undersized for a fuel cell system tliat does not include a thermally primed fuel processing
assembly, such as an assembly that includes a heated containment structure according to
the present disclosure. However, the hydrogen storage device and/or energy-storage
device may be sized to provide the required hydrogen gas and/or power output during the
much shorter time period that elapses for the thermally primed fuel cell system to begin
generating a sufficient power output to satisfy the applied load of energy-consuming
device 46. For example, this may enable the fuel cell system to provide an
uninterruptible backup power supply (UPS) for the energy-consuming device.
Industrial Applicability
Thermally primed fuel processing assemblies and hydrogen-producing fuel cell
systems containing the same are applicable to the fuel processing, fuel cell and other
industries in which hydrogen gas is produced, and in the case of fuel cell systems,
consumed by a fuel cell stack to produce an electric current.
It is believed that the disclosure set forth above encompasses multiple distinct
inventions with independent utility, ^^^lile each of these inventions has been disclosed in
its preferred form, the specific embodiments thereof as disclosed and illustrated herein are
not to be considered in a limiting sense as numerous variations are possible. The subject
matter of the inventions includes all novel and non-obvious combinations and
subcombinations of the various elements, features, functions and/or properties disclosed
herein. Similarly, where the claims recite "a" or "a first" element or the equivalent
thereof, such claims should be understood to include incorporation of one or more such
elements, neither requiring nor excluding two or more such elements.
It is believed that the following claims particularly point out certain combinations
and subcombinations that are directed to one of the disclosed inventions and are novel
and non-obvious. Inventions embodied in other combinations and subcombinations of
features, functions, elements and/or properties may be claimed through amendment of the
present claims or presentation of new claims in this or a related application. Such

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amended or new claims, whether they are directed to a different invention or directed to
the same invention, whether different, broader, narrower, or equal in scope to the original
claims, are also regarded as included within the subject matter of tlie inventions of the
present disclosure.

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CLAIMS:
1. A thermally primed hydrogen-producing fuel cell system, comprising:
a fuel processing assembly comprising a hydrogen-producing region that contains
a reforming catalyst, wherein the hydrogen-producing region is adapted to receive a feed
stream containing at least a carbon-containing feedstock and water and to produce from
the feed stream a reform ate stream containing hydrogen gas as a majority component;
a fuel cell stack adapted to receive an oxidsmt and a fuel stream containing
hydrogen gas produced in the hydrogen-producing region, wherein the fuel cell stack is
further adapted to generate a power output from the fuel stream and the oxidant;
a containment structure including an enclosure that defines an internal
compartment containing at least the hydrogen-producing region of the fuel processing
assembly; and
a heating assembly adapted to heat and maintain at least the internal compartment
of the containment structure at or above a threshold temperature during periods in which
the fuel cell system is not producing the power output and the fuel processing assembly is
not producing the refonnate stream.
2. The fiiel cell system of claim 1, wherein the fuel cell stack is adapted to
supply the power output to satisfy an applied load from an energy-consuming device
when a primary power source that is normally adapted to satisfy the applied load is not
providing a power output to satisfy the applied load.
3. The fuel cell system of claim 2, wherein the heating assembly is adapted
to be powered by the primary power source when the primary power source is configured
to satisfy the applied load from the energy-consuming device.
4. The fuel cell system of claim 2, wherein tlie primary power source
includes an electrical grid.
5. The fiiel cell system of claim 2, wherein tlie heating assembly is adapted
to stop heating the internal compartment when the fuel processing assembly is producing
hydrogen gas.

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6. The fuel cell system of claim 5, wherein the fuel processing assembly
further comprises a second heating assembly, wherein tlie second heating assembly is
positioned within the enclosure and is adapted to receive and combust a fuel stream.
7. The fuel cell system of claim 6, wherein the second heating assembly is
adapted to provide heat to at least tlie hydrogen-producing region of the fuel processing
assembly when the fuel processing assembly is producrag hydrogen gas.
8. The fuel cell system of claim 6, wherein the fuel stream is a gaseous fiiel
stream.
9. The fuel cell system of claim 8, wherein the gaseous fuel stream includes
hydrogen gas produced by the fuel processing assemblj'.

10. The fuel cell system of claim 1, wherein the hydrogen-producing region is
adapted to produce hydrogen gas from the feed stream, if delivered thereto, when the
hydrogen-producing region is at the threshold temperatare.
11. The fiiel cell system of claim 10, wherein the carbon-containing feedstock
is metlianol and the threshold temperature is at lejist 350° C.
12. The fuel cell system of claim 10, wherein the carbon-containing feedstock
is a hydrocarbon and the threshold temperature is at least 700° C.
13. The fliel cell system of claim 1, wherein the enclosure is an insulated
enclosure having an internal surface, which defines at least in part the internal
compartment, and an exterior surface, and further wherein the enclosure is adapted to
maintain the exterior surface at a temperature that is less than 100° C when the threshold
temperature is at least 350° C.
14. The fuel cell system of claim 13, wherein the enclosure is adapted to
maintain the exterior surface at a temperature that is less than 50° C when the threshold
temperature is at least 350° C.

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15. The fuel cell system of claim 1, wherein the fUel processing assembly
fiirther comprises at least one purification region adapted to receive at least a portion of
the refonnate stream and to produce a product hydrogen stream having at least one of a
greater concentration of hydrogen gas and a lower concentration of at least one of the
other gases present in the reformate stream.
16. The fuel cell sj'stem of claim 15, wherein the fuel processing assembly
includes at least one purification region within tlie internal compartment.
17. The fuel cell system of claim 15, wherein the fuel processing assembly
includes at least one purification region external the enclosure.

18. The fuel cell system of claim 1, wherein the fuel cell system further
includes an energy storage device adapted to satisfy an applied load fixjm at least one of
the fiiel cell system and an energy-consuming device.
19. The fuel cell system of claim 18, wherein the fuel cell system has a
thermally primed response time to produce hydrogen gas with the fuel processing
assembly when the fuel processing assembly has been heated to at least the threshold
temperature by the heating assembly and to generate the power output from hydrogen gas
produced by the fuel processing assembly, wherein the ener^ storage device has a
maximum charge that is adapted to satisfy an applied load for a time period, and further
wherein the time period is greater than the thermally primed response time.
20. The fuel cell system of claim 19, wherein the fuel cell system has a startup
response time to begin producing the power output from hydrogen gas when the fuel
processing assembly has not been heated to the threshold temperature by the heating
assembly, and further wherein the time period is less than the startup response time.

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21. A thennally primed hydrogen-producing fuel cell system, comprising:
a fuel processing assembly comprising a hydrogen-producing region that contains
a reforming catalyst, wherein the hydrogen-producing region is adapted to receive a feed
stream containing at least a carbon-containing feedstock and water and to pi-oduce from
the feed stream a refonnate stream containing hydrogen gas as a majority component;
a purification region adapted to receive at least a portion of the reformate stream
and to separate the portion into a product hydrogen stream containing greater hydrogen
purity than the reformate stream, and a byproduct stream;
a fuel cell stack adapted to receive an oxidant and a fuel stream containing
hydrogen gas produced in the hydrogen-producing region, wherein the fuel cell stack is
further adapted to generate a power output from the fuel stream and the oxidant;
a containment structure including an insulated enclosure that defines an internal
compartment containing at least the hydrogen-producing region and the purification
region of the fuel processing assembly; and
a heating assembly adapted to heat and maintain at least the internal compartment
of the containment structure at or above a threshold temperature of at least 350° C during
periods in which the fuel cell system is not producing the power output and the fuel
processing assembly is not producing the reformate stream, wherein the heating assembly
is not powered by the fuel cell system at least when the fuel cell system is not producing
the power output.
22. The fuel cell system of claim 21, wherein the heating assembly is an
electrically powered heating assembly.
23. The fuel cell system of claim 21, wherein the fuel cell system further
comprises a second heating assembly that is adapted to receive and combust at least the
byproduct stream, and further wherein the second heating assembly is contained within
the compartment.

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24. A method for using a thermally primed hydrogen-producing fuel cell
system, which includes at least a hydrogen-producing fuel processing assembly and a fuel
cell stack, to supplement a primai7 power source adapted to satisfy an applied load from
an energy-consuming device, the method comprising:
heating at least a hydrogen-producing region of a fuel processing assembly to at
least a threshold temperature at which the hydrogen-producing region is adapted to
produce a mixed gas stream containing hydrogen gas as a majority component from a
feed stream containing water and a carbon-containing feedstock;
maintaining the hydrogen-producing region at or above the threshold temperature
during periods in which tlie hydrogen-producing region is not producing hydrogen gas;
delivering at least water and a carbon-containing feedstock to the hydrogen-
producing region during a transition period in which there is a demand for a power output
from the fuel cell system to satisfy an applied load;
producing hydrogen gas in the hydrogen-producing region; and
generating the power output with the fuel cell stack from oxidant and hydrogen
gas produced in the hydrogen-producing region.
25. The method of claim 24, wherein the heating and maintaining is
performed by a heating assembly that is adapted to heat at least the hydrogen-producing
region of the fuel processing assembly.
26. The method of claim 25, wherein the heating assembly is an electrically
powered heating assembly that is adapted to be powered by the primary power source.
27. The method of claim 25, wherein the method further includes stopping the
maintaining by the heating assembly prior to the generating step.
28. The method of claim 21, wherein at least one of the heating and the
maintaining steps includes powering a heating assembly with the primary power source to
generate heat to heat the hydrogen-producing region.
29. The method of claim 21, wherein at least the hydrogen-producing region
of the fuel processing assembly is contained in an internal compartment of an enclosure,
and further wherein the heating and maintaining steps include utilizing a heating
assembly to heat the internal compartment to at least a threshold temperature.

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30. The method of claim 29, wherein the threshold temperature corresponds
to a temperature at which the hydrogen-producing region is adapted to produce, from
water and at least one carbon-containing feedstock, a stream containing hydrogen gas as a
majority component.
31. The method of claim 21, furtiier comprising detecting when the primaiy
power source is not able to satisfy the applied load from the energy-consuming device
and initiating the delivering step responsive at least in part thereto.
32. The method of claim 31, wherein upon the occurrence of the detecting
step, the method is adapted to complete the delivering and producing step and to initiate
the generating step in less than one minute.

Thermally primed fuel processing assemblies and hydrogen-producing fuel cell systems that include the same. The
thermally primed fuel processing assemblies include at least one hydrogen-producing region housed within an internal compartment
of a heated containment structure. In some embodiments, the heated containment structure is an oven. In some embodiments,
the compartment also contains a purification region and/or heating assembly. In some embodiments, the containment structure is
adapted to heat and maintain the internal compartment at or above a threshold temperature, which may correspond to a suitable
hydrogen-producing temperature. In some embodiments, the containment structure is adapted to maintain this temperature during
periods in which the fuel cell system is not producing power and/or not producing power to satisfy an applied load to the system. In
some embodiments, the fuel cell system is adapted to provide backup power to a power source, which may be adapted to power the
containment structure.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=7uIeUyM4AJ55yHXZlYmVDA==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 272380
Indian Patent Application Number 974/KOLNP/2008
PG Journal Number 14/2016
Publication Date 01-Apr-2016
Grant Date 30-Mar-2016
Date of Filing 05-Mar-2008
Name of Patentee IDATECH, LLC.
Applicant Address 63065 NE 18TH STREET BEND, OREGON
Inventors:
# Inventor's Name Inventor's Address
1 EDLUND, DAVID, J. 1698 NW DAVENPORT AVENUE, BEND, OR 97701
PCT International Classification Number H01M 8/06, H01M 8/04
PCT International Application Number PCT/US2006/033027
PCT International Filing date 2006-08-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/229365 2005-09-16 U.S.A.