U.S. patent application number 16/891477 was filed with the patent office on 2020-09-17 for hydrogen generation assemblies.
This patent application is currently assigned to Element 1 Corp.. The applicant listed for this patent is Element 1 Corp.. Invention is credited to David J Edlund, Robert Schluter.
Application Number | 20200289978 16/891477 |
Document ID | / |
Family ID | 1000004870134 |
Filed Date | 2020-09-17 |
United States Patent
Application |
20200289978 |
Kind Code |
A1 |
Edlund; David J ; et
al. |
September 17, 2020 |
HYDROGEN GENERATION ASSEMBLIES
Abstract
Hydrogen generation assemblies and methods of generating
hydrogen are disclosed. In some embodiments, the method may include
receiving a feed stream in a fuel processing assembly of the
hydrogen generation assembly; and generating a product hydrogen
stream in the fuel processing assembly from the received feed
stream. Generating a product hydrogen stream may, in some
embodiments, include generating an output stream in a hydrogen
generating region from the received feed stream, and generating the
product hydrogen stream in a purification region from the output
stream. The method may additionally include receiving the generated
product hydrogen stream in a buffer tank of the hydrogen generation
assembly; and detecting pressure in the buffer tank via a tank
sensor assembly. The method may further include stopping generation
of the product hydrogen stream in the fuel processing assembly when
the detected pressure in the buffer tank is above a predetermined
maximum pressure.
Inventors: |
Edlund; David J; (Bend,
OR) ; Schluter; Robert; (Bend, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Element 1 Corp. |
Bend |
OR |
US |
|
|
Assignee: |
Element 1 Corp.
Bend
OR
|
Family ID: |
1000004870134 |
Appl. No.: |
16/891477 |
Filed: |
June 3, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15985175 |
May 21, 2018 |
10710022 |
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16891477 |
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15483265 |
Apr 10, 2017 |
10166506 |
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15985175 |
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14931585 |
Nov 3, 2015 |
9616389 |
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15483265 |
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13829766 |
Mar 14, 2013 |
9187324 |
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14931585 |
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13600096 |
Aug 30, 2012 |
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13829766 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C01B 3/323 20130101;
C01B 2203/1247 20130101; C01B 3/22 20130101; C01B 2203/0405
20130101; C01B 2203/1223 20130101; C01B 2203/169 20130101; B01D
53/22 20130101; C01B 2203/0811 20130101; C01B 2203/0205 20130101;
C01B 2203/1235 20130101; C01B 2203/0244 20130101; C01B 2203/1229
20130101; C01B 2203/16 20130101; C01B 3/32 20130101; B01D 2313/26
20130101; B01D 2313/23 20130101; C01B 2203/146 20130101; C01B
2203/0445 20130101; C01B 2203/1217 20130101; B01D 63/087 20130101;
C01B 2203/044 20130101; C01B 2203/1241 20130101; C01B 2203/047
20130101; B01D 2313/14 20130101; C01B 3/34 20130101; C01B 2203/1619
20130101; C01B 2203/0283 20130101; C01B 2203/043 20130101; C01B
3/24 20130101; C01B 3/503 20130101; B01D 2053/222 20130101 |
International
Class: |
B01D 53/22 20060101
B01D053/22; C01B 3/32 20060101 C01B003/32; C01B 3/50 20060101
C01B003/50; B01D 63/08 20060101 B01D063/08; C01B 3/22 20060101
C01B003/22; C01B 3/24 20060101 C01B003/24; C01B 3/34 20060101
C01B003/34 |
Claims
1. A hydrogen generation assembly, comprising: a fuel processing
assembly configured to receive a feed stream and produce a product
hydrogen stream from the feed stream; a pressurized gas assembly
configured to receive at least one container of pressurized gas
that is configured to purge the fuel processing assembly; a purge
conduit configured to fluidly connect the pressurized gas assembly
and the fuel processing assembly; and a purge valve assembly
configured to allow the at least one pressurized gas to flow
through the purge conduit from the pressurized gas assembly to the
fuel processing assembly when power to the fuel processing assembly
is interrupted.
2. The assembly of claim 1, wherein the purge valve assembly
includes a purge valve that moves between a closed position in
which the at least one pressurized gas does not flow through the
purge conduit from the pressurized gas assembly, and an open
position in which the at least one pressurized gas is allowed to
flow through the purge conduit from the pressurized gas
assembly.
3. The assembly of claim 2, wherein the purge valve is in the
closed position when there is power to the fuel processing
assembly, and wherein the purge valve automatically moves to the
open position when power to the fuel processing assembly is
interrupted.
4. The assembly of claim 2, wherein the purge valve assembly
further includes a purge solenoid configured to move the purge
valve between the open and closed positions, the fuel processing
assembly including a control system configured to send a control
signal to the purge solenoid, and wherein the purge solenoid is
configured to move the purge valve to the closed position when the
purge solenoid receives the control signal, and to automatically
move the purge valve to the open position when the purge solenoid
does not receive the control signal.
5. The assembly of claim 1, wherein at least a portion of the fuel
processing assembly and at least a portion of the purge assembly
are contained within an enclosure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/985,175, filed May 21, 2018 and entitled
"Hydrogen Generation Assemblies", which is a continuation of U.S.
patent application Ser. No. 15/483,265, which was filed Apr. 10,
2017 and entitled "Hydrogen Generation Assemblies and Hydrogen
Purification Devices," which issued as U.S. Pat. No. 10,166,506 on
Jan. 1, 2019, which is a continuation application of U.S. patent
application Ser. No. 14/931,585, filed Nov. 3, 2015 and entitled
"Hydrogen Generation Assemblies and Hydrogen Purification Devices,"
which issued as U.S. Pat. No. 9,616,389 on Apr. 11, 2017, which is
a divisional application of U.S. patent application Ser. No.
13/829,766, filed Mar. 14, 2013 and entitled "Hydrogen Generation
Assemblies and Hydrogen Purification Devices," which issued as U.S.
Pat. No. 9,187,324 on Nov. 17, 2015, which is a
continuation-in-part application of U.S. patent application Ser.
No. 13/600,096, filed Aug. 30, 2012 and entitled "Hydrogen
Generation Assemblies." The complete disclosures of the above
applications are hereby incorporated by reference for all
purposes.
BACKGROUND OF THE DISCLOSURE
[0002] A hydrogen generation assembly is an assembly that converts
one or more feedstocks into a product stream containing hydrogen
gas as a majority component. The feedstocks may include a
carbon-containing feedstock and, in some embodiments, also may
include water. The feedstocks are delivered to a hydrogen-producing
region of the hydrogen generation assembly from a feedstock
delivery system, typically with the feedstocks being delivered
under pressure and at elevated temperatures. The hydrogen-producing
region is often associated with a temperature modulating assembly,
such as a heating assembly or cooling assembly, which consumes one
or more fuel streams to maintain the hydrogen-producing region
within a suitable temperature range for effectively producing
hydrogen gas. The hydrogen generation assembly may generate
hydrogen gas via any suitable mechanism(s), such as steam
reforming, autothermal reforming, pyrolysis, and/or catalytic
partial oxidation.
[0003] The generated or produced hydrogen gas may, however, have
impurities. That gas may be referred to as a mixed gas stream that
contains hydrogen gas and other gases. Prior to using the mixed gas
stream, it must be purified, such as to remove at least a portion
of the other gases. The hydrogen generation assembly may therefore
include a hydrogen purification device for increasing the hydrogen
purity of the mixed gas stream. The hydrogen purification device
may include at least one hydrogen-selective membrane to separate
the mixed gas stream into a product stream and a byproduct stream.
The product stream contains a greater concentration of hydrogen gas
and/or a reduced concentration of one or more of the other gases
from the mixed gas stream. Hydrogen purification using one or more
hydrogen-selective membranes is a pressure driven separation
process in which the one or more hydrogen-selective membranes are
contained in a pressure vessel. The mixed gas stream contacts the
mixed gas surface of the membrane(s), and the product stream is
formed from at least a portion of the mixed gas stream that
permeates through the membrane(s). The pressure vessel is typically
sealed to prevent gases from entering or leaving the pressure
vessel except through defined inlet and outlet ports or
conduits.
[0004] The product stream may be used in a variety of applications.
One such application is energy production, such as in
electrochemical fuel cells. An electrochemical fuel cell is a
device that converts fuel and an oxidant to electricity, a reaction
product, and heat. For example, fuel cells may convert hydrogen and
oxygen into water and electricity. In those fuel cells, the
hydrogen is the fuel, the oxygen is the oxidant, and the water is a
reaction product. Fuel cell stacks include a plurality of fuel
cells and may be utilized with a hydrogen generation assembly to
provide an energy production assembly.
[0005] Examples of hydrogen generation assemblies, hydrogen
processing assemblies, and/or components of those assemblies are
described in U.S. Pat. Nos. 5,861,137; 6,319,306; 6,494,937;
6,562,111; 7,063,047; 7,306,868; 7,470,293; 7,601,302; 7,632,322;
U.S. Patent Application Publication Nos. 2006/0090397;
2006/0272212; 2007/0266631; 2007/0274904; 2008/0085434;
2008/0138678; 2008/0230039; 2010/0064887; and U.S. patent
application Ser. No. 13/178,098. The complete disclosures of the
above patents and patent application publications are hereby
incorporated by reference for all purposes.
SUMMARY OF THE DISCLOSURE
[0006] Some embodiments may provide a hydrogen generation assembly.
In some embodiments, the hydrogen generation assembly may include a
fuel processing assembly configured to receive a feed stream and
produce a product hydrogen stream from the feed stream. The
hydrogen generation assembly may additionally include a feed
assembly configured to deliver the feed stream to the fuel
processing assembly. The feed assembly may include a feed tank
configured to contain feedstock for the feed stream, and a feed
conduit fluidly connecting the feed tank and the fuel processing
assembly. The feed assembly may additionally include a pump
configured to deliver the feed stream at a plurality of flowrates
to the fuel processing assembly via the feed conduit. The hydrogen
generation assembly may further include a control system. The
control system may include a feed sensor assembly configured to
detect pressure in the feed conduit downstream from the pump. The
control system may additionally include a pump controller
configured to select a flowrate from the plurality of flowrates
based on the detected pressure in the feed conduit, and to operate
the pump at the selected flowrate.
[0007] In some embodiments, the hydrogen generation assembly may
include a fuel processing assembly configured to receive a feed
stream and produce a product hydrogen stream from the feed stream.
The hydrogen generation assembly may additionally include a
pressurized gas assembly configured to receive at least one
container of pressurized gas that is configured to purge the fuel
processing assembly. The hydrogen generation assembly may further
include a purge conduit configured to fluidly connect the
pressurized gas assembly and the fuel processing assembly. The
hydrogen generation assembly may additionally include a purge valve
assembly configured to allow the at least one pressurized gas to
flow through the purge conduit from the pressurized gas assembly to
the fuel processing assembly when power to the fuel processing
assembly is interrupted.
[0008] In some embodiments, the hydrogen generation assembly may
include a fuel processing assembly configured to receive a feed
stream and to be operable among a plurality of modes, including a
run mode in which the fuel processing assembly produces a product
hydrogen stream from the feed stream, and a standby mode in which
the fuel processing assembly does not produce the product hydrogen
stream from the feed stream. The hydrogen generation assembly may
additionally include a buffer tank configured to contain the
product hydrogen stream, and a product conduit fluidly connecting
the fuel processing assembly and the buffer tank. The hydrogen
generation assembly may further include a tank sensor assembly
configured to detect pressure in the buffer tank, and a control
assembly configured to operate the fuel processing assembly between
the run and standby modes based, at least in part, on the detected
pressure in the buffer tank.
[0009] Some embodiments may provide a steam reforming hydrogen
generation assembly configured to receive at least one feed stream
and generate a reformate stream containing hydrogen gas as a
majority component and other gases. In some embodiments, the steam
reforming hydrogen generation assembly may include an enclosure
having an exhaust port, and a hydrogen-producing region contained
within the enclosure and configured to produce, via a steam
reforming reaction, the reformate stream from the at least one feed
stream. The steam reforming hydrogen generation assembly may
additionally include a reformer sensor assembly configured to
detect temperature in the hydrogen-producing region. The steam
reforming hydrogen generation assembly may further include a
heating assembly configured to receive at least one air stream and
at least one fuel stream and to combust the at least one fuel
stream within a combustion region contained within the enclosure
producing a heated exhaust stream for heating at least the
hydrogen-producing region to at least a minimum hydrogen-producing
temperature. The steam reforming hydrogen generation assembly may
additionally include a damper moveably connected to the exhaust
port and configured to move among a plurality of positions
including a fully open position in which the damper allows the
heated exhaust stream to flow through the exhaust port, a closed
position in which the damper prevents the heated exhaust stream
from flowing through the exhaust port, and a plurality of
intermediate open positions between the fully open and closed
positions. The steam reforming hydrogen generation assembly may
further include a damper controller configured to move the damper
between the fully open and closed positions based, at least in
part, on the detected temperature in the hydrogen-producing
region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view of an example of a hydrogen
generation assembly.
[0011] FIG. 2 is a schematic view of another example of a hydrogen
generation assembly.
[0012] FIG. 3 is a partial schematic view of an additional example
of a hydrogen generation assembly.
[0013] FIG. 4 is a schematic view of an example of a control
assembly.
[0014] FIG. 5 is a graph showing an example of the control assembly
of FIG. 4 receiving a detection signal and conditioning the
detection signal to generate a conditioned signal.
[0015] FIG. 6 is a partial schematic view of a further example of a
hydrogen generation assembly.
[0016] FIG. 7 is an example of a purge assembly of a hydrogen
generation assembly.
[0017] FIG. 8 is another example of a purge assembly of a hydrogen
generation assembly.
[0018] FIG. 9 is a partial schematic view of an additional example
of a hydrogen generation assembly.
[0019] FIGS. 10-12 are partial schematic views of the hydrogen
generation assembly of FIG. 9 showing another example of a damper
and examples of positions for that damper.
[0020] FIG. 13 is a partial schematic view of a further example of
a hydrogen generation assembly.
[0021] FIG. 14 is a partial schematic view of another example of a
hydrogen generation assembly.
[0022] FIG. 15 is a partial schematic view of the hydrogen
generation assembly of FIG. 14 showing a three-way valve in a flow
position.
[0023] FIG. 16 is a partial schematic view of the hydrogen
generation assembly of FIG. 14 showing the three-way valve of FIG.
15 in a vent position.
[0024] FIG. 17 is a partial schematic view of a further example of
a hydrogen generation assembly.
[0025] FIG. 18 is a partial schematic view of the hydrogen
generation assembly of FIG. 17 showing a first valve in an open
position and a second valve in a closed position.
[0026] FIG. 19 is a partial schematic view of the hydrogen
generation assembly of FIG. 17 showing the first valve of FIG. 18
in a closed position and the second valve of FIG. 18 in an open
position.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0027] FIG. 1 shows an example of a hydrogen generation assembly
20. Unless specifically excluded hydrogen generation assembly may
include one or more components of other hydrogen generation
assemblies described in this disclosure. The hydrogen generation
assembly may include any suitable structure configured to generate
a product hydrogen stream 21. For example, the hydrogen generation
assembly may include a feedstock delivery system 22 and a fuel
processing assembly 24. The feedstock delivery system may include
any suitable structure configured to selectively deliver at least
one feed stream 26 to the fuel processing assembly.
[0028] In some embodiments, feedstock delivery system 22 may
additionally include any suitable structure configured to
selectively deliver at least one fuel stream 28 to a burner or
other heating assembly of fuel processing assembly 24. In some
embodiments, feed stream 26 and fuel stream 28 may be the same
stream delivered to different parts of the fuel processing
assembly. The feedstock delivery system may include any suitable
delivery mechanisms, such as a positive displacement or other
suitable pump or mechanism for propelling fluid streams. In some
embodiments, feedstock delivery system may be configured to deliver
feed stream(s) 26 and/or fuel stream(s) 28 without requiring the
use of pumps and/or other electrically powered fluid-delivery
mechanisms. Examples of suitable feedstock delivery systems that
may be used with hydrogen generation assembly 20 include the
feedstock delivery systems described in U.S. Pat. Nos. 7,470,293
and 7,601,302, and U.S. Patent Application Publication No.
2006/0090397. The complete disclosures of the above patents and
patent application are hereby incorporated by reference for all
purposes.
[0029] Feed stream 26 may include at least one hydrogen-production
fluid 30, which may include one or more fluids that may be utilized
as reactants to produce product hydrogen stream 21. For example,
the hydrogen-production fluid may include a carbon-containing
feedstock, such as at least one hydrocarbon and/or alcohol.
Examples of suitable hydrocarbons include methane, propane, natural
gas, diesel, kerosene, gasoline, etc. Examples of suitable alcohols
include methanol, ethanol, polyols (such as ethylene glycol and
propylene glycol), etc. Additionally, hydrogen-production fluid 30
may include water, such as when fuel processing assembly generates
the product hydrogen stream via steam reforming and/or autothermal
reforming. When fuel processing assembly 24 generates the product
hydrogen stream via pyrolysis or catalytic partial oxidation, feed
stream 26 does not contain water.
[0030] In some embodiments, feedstock delivery system 22 may be
configured to deliver a hydrogen-production fluid 30 that contains
a mixture of water and a carbon-containing feedstock that is
miscible with water (such as methanol and/or another water-soluble
alcohol). The ratio of water to carbon-containing feedstock in such
a fluid stream may vary according to one or more factors, such as
the particular carbon-containing feedstock being used, user
preferences, design of the fuel processing assembly, mechanism(s)
used by the fuel processing assembly to generate the product
hydrogen stream etc. For example, the molar ratio of water to
carbon may be approximately 1:1 to 3:1. Additionally, mixtures of
water and methanol may be delivered at or near a 1:1 molar ratio
(37 weight % water, 63 weight % methanol), while mixtures of
hydrocarbons or other alcohols may be delivered at a
water-to-carbon molar ratio greater than 1:1.
[0031] When fuel processing assembly 24 generates product hydrogen
stream 21 via reforming, feed stream 26 may include, for example,
approximately 25-75 volume % methanol or ethanol (or another
suitable water-miscible carbon-containing feedstock) and
approximately 25-75 volume % water. For feed streams that at least
substantially include methanol and water, those streams may include
approximately 50-75 volume % methanol and approximately 25-50
volume % water. Streams containing ethanol or other water-miscible
alcohols may contain approximately 25-60 volume % alcohol and
approximately 40-75 volume % water. An example of a feed stream for
hydrogen generating assembly 20 that utilizes steam reforming or
autothermal reforming contains 69 volume % methanol and 31 volume %
water.
[0032] Although feedstock delivery system 22 is shown to be
configured to deliver a single feed stream 26, the feedstock
delivery system may be configured to deliver two or more feed
streams 26. Those streams may contain the same or different
feedstocks and may have different compositions, at least one common
component, no common components, or the same compositions. For
example, a first feed stream may include a first component, such as
a carbon-containing feedstock and a second feed stream may include
a second component, such as water. Additionally, although feedstock
delivery system 22 may, in some embodiments, be configured to
deliver a single fuel stream 28, the feedstock delivery system may
be configured to deliver two or more fuel streams. The fuel streams
may have different compositions, at least one common component, no
common components, or the same compositions. Moreover, the feed and
fuel streams may be discharged from the feedstock delivery system
in different phases. For example, one of the streams may be a
liquid stream while the other is a gas stream. In some embodiments,
both of the streams may be liquid streams, while in other
embodiments both of the streams may be gas streams. Furthermore,
although hydrogen generation assembly 20 is shown to include a
single feedstock delivery system 22, the hydrogen generation
assembly may include two or more feedstock delivery systems 22.
[0033] Fuel processing assembly 24 may include a hydrogen-producing
region 32 configured to produce an output stream 34 containing
hydrogen gas via any suitable hydrogen-producing mechanism(s). The
output stream may include hydrogen gas as at least a majority
component and may include additional gaseous component(s). Output
stream 34 may therefore be referred to as a "mixed gas stream" that
contains hydrogen gas as its majority component but which includes
other gases.
[0034] Hydrogen-producing region 32 may include any suitable
catalyst-containing bed or region. When the hydrogen-producing
mechanism is steam reforming, the hydrogen-producing region may
include a suitable steam reforming catalyst 36 to facilitate
production of output stream(s) 34 from feed stream(s) 26 containing
a carbon-containing feedstock and water. In such an embodiment,
fuel processing assembly 24 may be referred to as a "steam
reformer," hydrogen-producing region 32 may be referred to as a
"reforming region," and output stream 34 may be referred to as a
"reformate stream." The other gases that may be present in the
reformate stream may include carbon monoxide, carbon dioxide,
methane, steam, and/or unreacted carbon-containing feedstock.
[0035] When the hydrogen-producing mechanism is autothermal
reforming, hydrogen-producing region 32 may include a suitable
autothermal reforming catalyst to facilitate the production of
output stream(s) 34 from feed stream(s) 26 containing water and a
carbon-containing feedstock in the presence of air. Additionally,
fuel processing assembly 24 may include an air delivery assembly 38
configured to deliver air stream(s) to the hydrogen-producing
region.
[0036] In some embodiments, fuel processing assembly 24 may include
a purification (or separation) region 40, which may include any
suitable structure configured to produce at least one hydrogen-rich
stream 42 from output (or mixed gas) stream 34. Hydrogen-rich
stream 42 may include a greater hydrogen concentration than output
stream 34 and/or a reduced concentration of one or more other gases
(or impurities) that were present in that output stream. Product
hydrogen stream 21 includes at least a portion of hydrogen-rich
stream 42. Thus, product hydrogen stream 21 and hydrogen-rich
stream 42 may be the same stream and have the same composition and
flow rates. Alternatively, some of the purified hydrogen gas in
hydrogen-rich stream 42 may be stored for later use, such as in a
suitable hydrogen storage assembly and/or consumed by the fuel
processing assembly. Purification region 40 also may be referred to
as a "hydrogen purification device" or a "hydrogen processing
assembly."
[0037] In some embodiments, purification region 40 may produce at
least one byproduct stream 44, which may contain no hydrogen gas or
some hydrogen gas. The byproduct stream may be exhausted, sent to a
burner assembly and/or other combustion source, used as a heated
fluid stream, stored for later use, and/or otherwise utilized,
stored, and/or disposed. Additionally, purification region 40 may
emit the byproduct stream as a continuous stream responsive to the
deliver of output stream 34, or may emit that stream
intermittently, such as in a batch process or when the byproduct
portion of the output stream is retained at least temporarily in
the purification region.
[0038] Fuel processing assembly 24 may include one or more
purification regions configured to produce one or more byproduct
streams containing sufficient amounts of hydrogen gas to be
suitable for use as a fuel stream (or a feedstock stream) for a
heating assembly for the fuel processing assembly. In some
embodiments, the byproduct stream may have sufficient fuel value or
hydrogen content to enable a heating assembly to maintain the
hydrogen-producing region at a desired operating temperature or
within a selected range of temperatures. For example, the byproduct
stream may include hydrogen gas, such as 10-30 weight % hydrogen
gas, 15-25 weight % hydrogen gas, 20-30 weight % hydrogen gas, at
least 10 or 15 weight % hydrogen gas, at least 20 weight % hydrogen
gas, etc.
[0039] Purification region 40 may include any suitable structure
configured to reduce the concentration of at least one component of
output stream 21. In most applications, hydrogen-rich stream 42
will have a greater hydrogen concentration than output stream (or
mixed gas stream) 34. The hydrogen-rich stream also may have a
reduced concentration of one or more non-hydrogen components that
were present in output stream 34 with the hydrogen concentration of
the hydrogen-rich stream being more, the same, or less than the
output stream. For example, in conventional fuel cell systems,
carbon monoxide may damage a fuel cell stack if it is present in
even a few parts per million, while other non-hydrogen components
that may be present in output stream 34, such as water, will not
damage the stack even if present in much greater concentrations.
Therefore, in such an application, the purification region may not
increase the overall hydrogen concentration but will reduce the
concentration of one or more non-hydrogen components that are
harmful, or potentially harmful, to the desired application for the
product hydrogen stream.
[0040] Examples of suitable devices for purification region 40
include one or more hydrogen-selective membranes 46, chemical
carbon monoxide removal assemblies 48, and/or pressure swing
adsorption (PSA) systems 50. Purification region 40 may include
more than one type of purification device and the devices may have
the same or different structures and/or operate by the same or
difference mechanism(s). Fuel processing assembly 24 may include at
least one restrictive orifice and/or other flow restrictor
downstream of the purification region(s), such as associated with
one or more product hydrogen stream(s), hydrogen-rich stream(s),
and/or byproduct stream(s).
[0041] Hydrogen-selective membranes 46 are permeable to hydrogen
gas, but are at least substantially (if not completely) impermeable
to other components of output stream 34. Membranes 46 may be formed
of any hydrogen-permeable material suitable for use in the
operating environment and parameters in which purification region
40 is operated. Examples of suitable materials for membranes 46
include palladium and palladium alloys, and especially thin films
of such metals and metal alloys. Palladium alloys have proven
particularly effective, especially palladium with 35 weight % to 45
weight % copper. A palladium-copper alloy that contains
approximately 40 weight % copper has proven particularly effective,
although other relative concentrations and components may be used.
Another especially effective alloy is palladium with 2 weight % to
10 weight % gold, especially palladium with 5 weight % gold. When
palladium and palladium alloys are used, hydrogen-selective
membranes 46 may sometimes be referred to as "foils."
[0042] Chemical carbon monoxide removal assemblies 48 are devices
that chemically react carbon monoxide and/or other undesirable
components of output stream 34 to form other compositions that are
not as potentially harmful. Examples of chemical carbon monoxide
removal assemblies include water-gas shift reactors that are
configured to produce hydrogen gas and carbon dioxide from water
and carbon monoxide, partial oxidation reactors that are configured
to convert carbon monoxide and oxygen (usually from air) into
carbon dioxide, and methanation reactors that are configured to
convert carbon monoxide and hydrogen to methane and water. Fuel
processing assembly 24 may include more than one type and/or number
of chemical removal assemblies 48.
[0043] Pressure swing adsorption (PSA) is a chemical process in
which gaseous impurities are removed from output stream 34 based on
the principle that certain gases, under the proper conditions of
temperature and pressure, will be adsorbed onto an adsorbent
material more strongly than other gases. Typically, the
non-hydrogen impurities are adsorbed and removed from output stream
34. 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. PSA system 50 also provides an
example of a device for use in purification region 40 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.
[0044] In FIG. 1, purification region 40 is shown within fuel
processing assembly 24. The purification region may alternatively
be separately located downstream from the fuel processing assembly,
as is schematically illustrated in dash-dot lines in FIG. 1.
Purification region 40 also may include portions within and
external to the fuel processing assembly.
[0045] Fuel processing assembly 24 also may include a temperature
modulating assembly in the form of a heating assembly 52. The
heating assembly may be configured to produce at least one heated
exhaust stream (or combustion stream) 54 from at least one heating
fuel stream 28, typically as combusted in the presence of air.
Heated exhaust stream 54 is schematically illustrated in FIG. 1 as
heating hydrogen-producing region 32. Heating assembly 52 may
include any suitable structure configured to generate the heated
exhaust stream, such as a burner or combustion catalyst in which a
fuel is combusted with air to produce the heated exhaust stream.
The heating assembly may include an ignitor or ignition source 58
that is configured to initiate the combustion of fuel. Examples of
suitable ignition sources include one or more spark plugs, glow
plugs, combustion catalyst, pilot lights, piezoelectric ignitors,
spark igniters, hot surface igniters, etc.
[0046] In some embodiments, heating assembly 52 may include a
burner assembly 60 and may be referred to as a combustion-based, or
combustion-driven, heating assembly. In a combustion-based heating
assembly, heating assembly 52 may be configured to receive at least
one fuel stream 28 and to combust the fuel stream in the presence
of air to provide a hot combustion stream 54 that may be used to
heat at least the hydrogen-producing region of the fuel processing
assembly. Air may be delivered to the heating assembly via a
variety of mechanisms. For example, an air stream 62 may be
delivered to the heating assembly as a separate stream, as shown in
FIG. 1. Alternatively, or additionally, air stream 62 may be
delivered to the heating assembly with at least one of the fuel
streams 28 for heating assembly 52 and/or drawn from the
environment within which the heating assembly is utilized.
[0047] Combustion stream 54 may additionally, or alternatively, be
used to heat other portions of the fuel processing assembly and/or
fuel cell systems with which the heating assembly is used.
Additionally, other configuration and types of heating assemblies
52 may be used. For example, heating assembly 52 may be an
electrically powered heating assembly that is configured to heat at
least hydrogen-producing region 32 of fuel processing assembly 24
by generating heat using at least one heating element, such as a
resistive heating element. In those embodiments, heating assembly
52 may not receive and combust a combustible fuel stream to heat
the hydrogen-producing region to a suitable hydrogen-producing
temperature. Examples of heating assemblies are disclosed in U.S.
Pat. No. 7,632,322, the complete disclosure of which is hereby
incorporated by reference for all purposes.
[0048] Heating assembly 52 may be housed in a common shell or
housing with the hydrogen-producing region and/or separation region
(as further discussed below). The heating assembly may be
separately positioned relative to hydrogen-producing region 32 but
in thermal and/or fluid communication with that region to provide
the desired heating of at least the hydrogen-producing region.
Heating assembly 52 may be located partially or completely within
the common shell, and/or at least a portion (or all) of the heating
assembly may be located external that shell. When the heating
assembly is located external the shell, the hot combustion gases
from burner assembly 60 may be delivered via suitable heat transfer
conduits to one or more components within the shell.
[0049] The heating assembly also may be configured to heat
feedstock delivery system 22, the feedstock supply streams,
hydrogen-producing region 32, purification (or separation) region
40, or any suitable combination of those systems, streams, and
regions. Heating of the feedstock supply streams may include
vaporizing liquid reactant streams or components of the
hydrogen-production fluid used to produce hydrogen gas in the
hydrogen-producing region. In that embodiment, fuel processing
assembly 24 may be described as including a vaporization region 64.
The heating assembly may additionally be configured to heat other
components of the hydrogen generation assembly. For example, the
heated exhaust stream may be configured to heat a pressure vessel
and/or other canister containing the heating fuel and/or the
hydrogen-production fluid that forms at least portions of feed
stream 26 and fuel stream 28.
[0050] Heating assembly 52 may achieve and/or maintain in
hydrogen-producing region 32 any suitable temperatures. Steam
reformers typically operate at temperatures in the range of
200.degree. C. and 900.degree. C. However, temperatures outside
this range are within the scope of this disclosure. When the
carbon-containing feedstock is methanol, the steam reforming
reaction will typically operate in a temperature range of
approximately 200-500.degree. C. Example subsets of that range
include 350-450.degree. C., 375-425.degree. C., and 375-400.degree.
C. When the carbon-containing feedstock is a hydrocarbon, ethanol
or another alcohol, a temperature range of approximately
400-900.degree. C. will typically be used for the steam reforming
reaction. Example subsets of that range include 750-850.degree. C.,
725-825.degree. C., 650-750.degree. C., 700-800.degree. C.,
700-900.degree. C., 500-800.degree. C., 400-600.degree. C., and
600-800.degree. C. Hydrogen-producing region 32 may 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,
hydrogen-producing region 32 may include two different
hydrogen-producing portions, or regions, with one operating at a
lower temperature than the other to provide a pre-reforming region.
In those embodiments, the fuel processing assembly may also be
referred to as including two or more hydrogen-producing
regions.
[0051] Fuel stream 28 may include any combustible liquid(s) and/or
gas(es) that are suitable for being consumed by heating assembly 52
to provide the desired heat output. Some fuel streams may be gases
when delivered and combusted by heating assembly 52, while others
may be delivered to the heating assembly as a liquid stream.
Examples of suitable heating fuels for fuel streams 28 include
carbon-containing feedstocks, such as methanol, methane, ethane,
ethanol, ethylene, propane, propylene, butane, etc. Additional
examples include low molecular weight condensable fuels, such as
liquefied petroleum gas, ammonia, lightweight amines, dimethyl
ether, and low molecular weight hydrocarbons. Yet other examples
include hydrogen and carbon monoxide. In embodiments of hydrogen
generation assembly 20 that include a temperature modulating
assembly in the form of a cooling assembly instead of a heating
assembly (such as may be used when an exothermic
hydrogen-generating process--e.g., partial oxidation--is utilized
instead of an endothermic process such as steam reforming), the
feedstock delivery system may be configured to supply a fuel or
coolant stream to the assembly. Any suitable fuel or coolant fluid
may be used.
[0052] Fuel processing assembly 24 may additionally include a shell
or housing 66 in which at least hydrogen-producing region 32 is
contained, as shown in FIG. 1. In some embodiments, vaporization
region 64 and/or purification region 40 may additionally be
contained within the shell. Shell 66 may enable components of the
steam reformer or other fuel processing mechanism to be moved as a
unit. The shell also may protect components of the fuel processing
assembly from damage by providing a protective enclosure and/or may
reduce the heating demand of the fuel processing assembly because
components may be heated as a unit. Shell 66 may include insulating
material 68, such as a solid insulating material, blanket
insulating material, and/or an air-filled cavity. The insulating
material may be internal the shell, external the shell, or both.
When the insulating material is external a shell, fuel processing
assembly 24 may further include an outer cover or jacket 70
external the insulation, as schematically illustrated in FIG. 1.
The fuel processing assembly may include a different shell that
includes additional components of the fuel processing assembly,
such as feedstock delivery system 22 and/or other components.
[0053] One or more components of fuel processing assembly 24 may
either extend beyond the shell or be located external the shell.
For example, purification region 40 may be located external shell
66, such as being spaced-away from the shell but in fluid
communication by suitable fluid-transfer conduits. As another
example, a portion of hydrogen-producing region 32 (such as
portions of one or more reforming catalyst beds) may extend beyond
the shell, such as indicated schematically with a dashed line
representing an alternative shell configuration in FIG. 1. Examples
of suitable hydrogen generation assemblies and its components are
disclosed in U.S. Pat. Nos. 5,861,137; 5,997,594; and 6,221,117,
the complete disclosures of which are hereby incorporated by
reference for all purposes.
[0054] Another example of hydrogen generation assembly 20 is shown
in FIG. 2, and is generally indicated at 72. Unless specifically
excluded, hydrogen generation assembly 72 may include one or more
components of hydrogen generation assembly 20. Hydrogen-generation
assembly 72 may include a feedstock delivery system 74, a
vaporization region 76, a hydrogen-producing region 78, and a
heating assembly 80, as shown in FIG. 2. In some embodiments,
hydrogen generation assembly 20 also may include a purification
region 82.
[0055] The feedstock delivery system may include any suitable
structure configured to deliver one or more feed and/or fuel
streams to one or more other components of the hydrogen-generation
assembly. For example, feedstock delivery system may include a
feedstock tank (or container) 84 and a pump 86. The feedstock tank
may contain any suitable hydrogen-production fluid 88, such as
water and a carbon-containing feedstock (e.g., a methanol/water
mixture). Pump 86 may have any suitable structure configured to
deliver the hydrogen-production fluid, which may be in the form of
at least one liquid-containing feed stream 90 that includes water
and a carbon-containing feedstock, to vaporization region 76 and/or
hydrogen-producing region 78.
[0056] Vaporization region 76 may include any suitable structure
configured to receive and vaporize at least a portion of a
liquid-containing feed stream, such as liquid-containing feed
stream 90. For example, vaporization region 76 may include a
vaporizer 92 configured to at least partially transform
liquid-containing feed stream 90 into one or more vapor feed
streams 94. The vapor feed streams may, in some embodiments,
include liquid. An example of a suitable vaporizer is a coiled tube
vaporizer, such as a coiled stainless steel tube.
[0057] Hydrogen-producing region 78 may include any suitable
structure configured to receive one of more feed streams, such as
vapor feed stream(s) 94 from the vaporization region, to produce
one or more output streams 96 containing hydrogen gas as a majority
component and other gases. The hydrogen-producing region may
produce the output stream via any suitable mechanism(s). For
example, hydrogen-producing region 78 may generate output stream(s)
96 via a steam reforming reaction. In that example,
hydrogen-producing region 78 may include a steam reforming region
97 with a reforming catalyst 98 configured to facilitate and/or
promote the steam reforming reaction. When hydrogen-producing
region 78 generates output stream(s) 96 via a steam reforming
reaction, hydrogen generation assembly 72 may be referred to as a
"steam reforming hydrogen generation assembly" and output stream 96
may be referred to as a "reformate stream."
[0058] Heating assembly 80 may include any suitable structure
configured to produce at least one heated exhaust stream 99 for
heating one or more other components of the hydrogen generation
assembly 72. For example, the heating assembly may heat the
vaporization region to any suitable temperature(s), such as at
least a minimum vaporization temperature or the temperature in
which at least a portion of the liquid-containing feed stream is
vaporized to form the vapor feed stream. Additionally, or
alternatively, heating assembly 80 may heat the hydrogen-producing
region to any suitable temperature(s), such as at least a minimum
hydrogen-producing temperature or the temperature in which at least
a portion of the vapor feed stream is reacted to produce hydrogen
gas to form the output stream. The heating assembly may be in
thermal communication with one or more components of the hydrogen
generation assembly, such as the vaporization region and/or
hydrogen-producing region.
[0059] The heating assembly may include a burner assembly 100, at
least one air blower 102, and an igniter assembly 104, as shown in
FIG. 2. The burner assembly may include any suitable structure
configured to receive at least one air stream 106 and at least one
fuel stream 108 and to combust the at least one fuel stream within
a combustion region 110 to produce heated exhaust stream 99. The
fuel stream may be provided by feedstock delivery system 74 and/or
purification region 82. The combustion region may be contained
within an enclosure of the hydrogen generation assembly. Air blower
102 may include any suitable structure configured to generate air
stream(s) 106. Igniter assembly 104 may include any suitable
structure configured to ignite fuel stream(s) 108.
[0060] Purification region 82 may include any suitable structure
configured to produce at least one hydrogen-rich stream 112, which
may include a greater hydrogen concentration than output stream 96
and/or a reduced concentration of one or more other gases (or
impurities) that were present in that output stream. The
purification region may produce at least one byproduct stream or
fuel stream 108, which may be sent to burner assembly 100 and used
as a fuel stream for that assembly, as shown in FIG. 2.
Purification region 82 may include a flow restricting orifice 111,
a filter assembly 114, a membrane assembly 116, and a methanation
reactor assembly 118. The filter assembly (such as one or more hot
gas filters) may be configured to remove impurities from output
stream 96 prior to the hydrogen purification membrane assembly.
[0061] Membrane assembly 116 may include any suitable structure
configured to receive output or mixed gas stream(s) 96 that
contains hydrogen gas and other gases, and to generate permeate or
hydrogen-rich stream(s) 112 containing a greater concentration of
hydrogen gas and/or a lower concentration of other gases than the
mixed gas stream. Membrane assembly 116 may incorporate
hydrogen-permeable (or hydrogen-selective) membranes that are
planar or tubular, and more than one hydrogen-permeable membrane
may be incorporated into membrane assembly 116. The permeate
stream(s) may be used for any suitable applications, such as for
one or more fuel cells. In some embodiments, the membrane assembly
may generate a byproduct or fuel stream 108 that includes at least
a substantial portion of the other gases. Methanation reactor
assembly 118 may include any suitable structure configured to
convert carbon monoxide and hydrogen to methane and water. Although
purification region 82 is shown to include flow restricting orifice
111, filter assembly 114, membrane assembly 116, and methanation
reactor assembly 118, the purification region may have less than
all of those assemblies, and/or may alternatively, or additionally,
include one or more other components configured to purify output
stream 96. For example, purification region 82 may include only
membrane assembly 116.
[0062] In some embodiments, hydrogen generation assembly 72 may
include a shell or housing 120 which may at least partially contain
one or more other components of that assembly. For example, shell
120 may at least partially contain vaporization region 76,
hydrogen-producing region 78, heating assembly 80, and/or
purification region 82, as shown in FIG. 2. Shell 120 may include
one or more exhaust ports 122 configured to discharge at least one
combustion exhaust stream 124 produced by heating assembly 80.
[0063] Hydrogen generation assembly 72 may, in some embodiments,
include a control system 126, which may include any suitable
structure configured to control operation of hydrogen generation
assembly 72. For example, control assembly 126 may include a
control assembly 128, at least one valve 130, at least one pressure
relief valve 132, and one or more temperature measurement devices
134. Control assembly 128 may detect temperatures in the
hydrogen-producing region and/or purification regions via the
temperature measurement device 134, which may include one or more
thermocouples and/or other suitable devices. Based on the detected
temperatures, the control assembly and/or an operator of the
control system may adjust delivery of feed stream 90 to
vaporization region 76 and/or hydrogen-producing region 78 via
valve(s) 130 and pump(s) 86. Valve(s) 130 may include a solenoid
valve and/or any suitable valve(s). Pressure relief valve(s) 132
may be configured to ensure that excess pressure in the system is
relieved.
[0064] In some embodiments, hydrogen generation assembly 72 may
include a heat exchange assembly 136, which may include one or more
heat exchangers 138 configured to transfer heat from one portion of
the hydrogen generation assembly to another portion. For example,
heat exchange assembly 136 may transfer heat from hydrogen-rich
stream 112 to feed stream 90 to raise the temperature of the feed
stream prior to entering vaporization region 76, as well as to cool
hydrogen-rich stream 112.
[0065] Another example of hydrogen generation assembly 20 is
generally indicated at 140 in FIG. 3. Unless specifically excluded,
hydrogen generation assembly 140 may include one or more components
of one or more other hydrogen generation assemblies described in
this disclosure. Hydrogen generation assembly 140 may include a
feedstock delivery system or feed assembly 142 and a fuel
processing assembly 144 configured to receive at least one feed
stream from the feedstock delivery system and produce one or more
product hydrogen stream(s), such as a hydrogen gas stream, from the
feed stream(s).
[0066] The feedstock delivery system may include any suitable
structure configured to deliver one or more feed and/or fuel
streams to one or more other components of the hydrogen generation
assembly, such as fuel processing assembly 144. For example, the
feedstock delivery system may include a feedstock tank or feed tank
(and/or container) 146, a feed conduit 148, a pump 150, and a
control system 152. The feed tank may contain feedstock for one or
more feed streams of the fuel processing assembly. For example,
feed tank 146 may contain any suitable hydrogen-production fluid,
such as water and a carbon-containing feedstock (e.g., a
methanol/water mixture).
[0067] Feed conduit 148 may fluidly connect feed tank 146 with fuel
processing assembly 144. The feed conduit may include a feed
portion 154 and a bypass portion 156. The bypass portion may be
configured to prevent overpressurization in the feed conduit, in
the fuel processing assembly, and/or in one or more other
components of hydrogen generation assembly 140. For example, bypass
portion 156 may include a valve assembly 158, such as a pressure
relief valve or a check valve.
[0068] Pump 150 may have any suitable structure configured to
deliver one or more feed and/or fuel streams to the fuel processing
assembly at a plurality of flowrates to fuel processing assembly
144 via, for example, feed conduit 148. For example, pump 150 may
be a variable-speed pump (or a pump that includes a variable speed
motor) that injects the feed and/or fuel streams into the fuel
processing assembly under pressure. The pump may operate at a speed
based on a control signal from the control system. For example,
pump 150 may operate or turn at a higher speed (which results in
the pump discharging the feed and/or fuel streams at a higher
flowrate) when the control signal increases in magnitude, while the
pump may operate or turn at a lower speed (which results in the
pump discharging the feed and/or fuel streams at a lower flowrate)
when the control signal decreases in magnitude.
[0069] Pressure in the fuel processing assembly (such as in the
hydrogen-producing region of the fuel processing assembly) may
increase with higher pump flowrates and may decrease with lower
pump flowrates. For example, one or more fixed flow restriction
devices in the fuel processing assembly may cause a proportional
increase in pressure with higher pump flowrates, and a proportional
decrease in pressure with lower pump flowrates. Because feed
conduit 148 fluidly connects the feedstock delivery system and the
fuel processing assembly, an increase (or decrease) in pressure in
the fuel processing assembly may result in an increase (or
decrease) in pressure in the feed conduit downstream from pump
150.
[0070] Control system 152 may include any suitable structure
configured to control and/or operate pump 150 and/or other
controlled devices of hydrogen generation assembly 140. For
example, control system 152 may include a sensor assembly 160, a
control assembly 162, and communication linkages 164.
[0071] The sensor assembly may include any suitable structure
configured to detect and/or measure one or more suitable operating
variables and/or parameters in the hydrogen generation assembly
and/or generate one or more signals based on the detected and/or
measured operating variable(s) and/or parameter(s). For example,
the sensor assembly may detect mass, volume, flow, temperature,
electrical current, pressure, refractive index, thermal
conductivity, density, viscosity, optical absorbance, electrical
conductivity, and/or other suitable variable(s), and/or
parameter(s). In some embodiments, the sensor assembly may detect
one or more triggering events. A "triggering event," as used
herein, is a measurable event in which a predetermined threshold
value or range of values representative of a predetermined amount
of one or more of the components forming one or more streams
associated with the hydrogen generation assembly is reached or
exceeded.
[0072] For example, sensor assembly 160 may include one or more
sensors 166 configured to detect pressure, temperature, flowrate,
volume, and/or other parameters. Sensors 166 may, for example,
include at least one feed sensor 168 configured to detect one or
more suitable operating variables, parameters, and/or triggering
events in feed conduit 148. The feed sensor may be configured to
detect, for example, pressure in the feed conduit and/or generate
one or more signals based on the detected pressure.
[0073] Control assembly 162 may be configured to communicate with
sensor assembly 160 and pump 150 (and/or other controlled devices
of hydrogen generation assembly 140) via communication linkages
164. For example, control assembly 162 may include any suitable
structure configured to select a flowrate from the plurality of
flowrates of pump 150 based on the detected pressure in the feed
conduit, and/or to operate the pump at the selected flowrate.
Communication linkages 164 may be any suitable wired and/or
wireless mechanism for one- or two-way communication between the
corresponding devices, such as input signals, command signals,
measured parameters, etc.
[0074] Control assembly 162 may, for example, include at least one
processor 170, as shown in FIG. 4. The processor may communicate
with sensor assembly 160 and pump 150 and/or other
controlled-devices via communication linkages 148. Processor 170
may have any suitable form, such as a computerized device, software
executing on a computer, an embedded processor, programmable logic
controller, an analog device (with one or more resistors), and/or
functionally equivalent devices. The control assembly may include
any suitable software, hardware, and/or firmware. For example,
control assembly 162 may include memory device(s) 172 in which
preselected, preprogrammed, and/or user-selected operating
parameters may be stored. The memory device may include volatile
portion(s), nonvolatile portion(s), and/or both.
[0075] In some embodiments, processor 170 may be in the form of a
signal conditioner 174, which may include any suitable structure
configured to condition one or more signals received from sensor
assembly 160. The signal conditioner may amplify, filter, convert,
invert, range match, isolate, and/or otherwise modify one or more
signals received from the sensor assembly such that the conditioned
signals are suitable for downstream components. For example, signal
conditioner 174 may invert one or more signals received from sensor
assembly 160. "Invert," as used herein, refers to one or more of
the following: converting a signal with a characteristic having
ascending values to a signal with the characteristic having
descending values, converting a signal with a characteristic having
descending values to a signal with the characteristic having
ascending values, converting a signal with a characteristic having
a high value to a signal with the characteristic having a low value
(or having the highest value to the lowest value), and/or
converting a signal with a characteristic having a low value to a
signal with the characteristic having a high value (or having the
lowest value to the highest value). Characteristics of the signals
may include voltage, current, etc. One or more of the converted
values may match and/or correspond to values from the original
signal, such as converting the highest original value to the lowest
original value and/or converting the lowest original value to the
highest original value. Alternatively, one or more of the converted
values may be different from the original values of the
signals.
[0076] In some embodiments, control assembly 162 may include a user
interface 176, as shown in FIG. 4. The user interface may include
any suitable structure configured to allow a user to monitor and/or
interact with operation of processor 170. For example, user
interface 176 may include a display region 178, a user input device
180, and/or a user-signaling device 182, as shown in FIG. 4. The
display region may include a screen and/or other suitable display
mechanism in which information is presented to the user. For
example, display region 178 may display current values measured by
one or more sensors 166, current operating parameters of the
hydrogen generation assembly, stored threshold values or ranges,
previously measured values, and/or other information regarding the
operation and/or performance of the hydrogen generation
assembly.
[0077] User input device 180 may include any suitable structure
configured to receive input from the user and send that input to
processor 170. For example, the user input device may include
rotary dials, switches, push-buttons, keypads, keyboards, a mouse,
touch screens, etc. User input device 180 may, for example, enable
a user to specify how signals from sensor assembly 160 will be
conditioned, such as whether the signal will be inverted, what the
range of values of the inverted signal should be, etc.
User-signaling device 182 may include any suitable structure
configured to alert a user when an acceptable threshold level has
been exceeded. For example, the user-signaling device may include
an alarm, lights, and/or other suitable mechanism(s) for alerting a
user.
[0078] In some embodiments, control assembly 162 may be configured
to only condition signals received from sensor assembly 160 via
signal conditioner 168 without additional processing of the signal
and/or sending a different signal. In other words, the signal(s)
from sensor assembly 160 may be conditioned via signal conditioner
168 and the conditioned signals may be sent to pump 150 and/or
other controlled device(s) via communication linkages 164 to
operate the pump and/or other controlled devices without additional
processing by the control assembly and/or other assemblies.
[0079] The conditioned signal (such as an inverted signal) may be
configured, for example, to select a flowrate for pump 150 from the
plurality of flowrates. When the conditioned signal is configured
to select a flowrate for the pump, the control assembly may be
described as being configured to select the flowrate based on (or
based solely on) the conditioned signal.
[0080] An example of controlling pump 150 with a conditioned signal
is shown in graph 184 in FIG. 5. Sensor assembly 160 may include
feed sensor 168 that detects pressure and sends a detection signal
186 to control assembly 162 based on the detected pressure. The
detection signal may be a voltage signal as shown in FIG. 5, a
current signal, and/or other suitable signals that are proportional
to the detected pressure. The detection signal(s) may be any
suitable voltage(s) and/or current(s), such as 0-5 volts and/or
4-20 milliampere (mA).
[0081] Control assembly 162 may condition (such as invert) the
detection signal into a conditioned signal 188 such that the
conditioned signal is configured to select one or more parameters
(such as flowrate and/or speed) for pump 150 and/or other
controlled devices. The conditioned signal(s) may be any suitable
voltage(s) and/or current(s), such as 0-5 volts and/or 4-20 mA. The
voltages and pressure shown in FIG. 5 are only one example of the
various voltages and pressures that may be generated and/or
detected by control system 152. In other words, control system 152
is not limited to operation in the voltages and pressures shown in
that figure.
[0082] Another example of hydrogen generation assembly 20 is
generally indicated at 190 in FIG. 6. Unless specifically excluded,
hydrogen generation assembly 190 may include one or more components
of one or more other hydrogen generation assemblies described in
this disclosure. Hydrogen generation assembly 190 may include a
feedstock delivery system or feed assembly 192 and a fuel
processing assembly 194 configured to receive at least one feed
stream from the feedstock delivery system and produce one or more
product hydrogen stream(s), such as a hydrogen gas stream, from the
feed stream(s).
[0083] The feedstock delivery system may include a feedstock tank
or feed tank (and/or container) 196, a feed conduit 198, a pump
200, and a control system 202. The feed tank may contain feedstock
for one or more feed streams of the fuel processing assembly. Feed
conduit 198 may fluidly connect feed tank 196 with fuel processing
assembly 194. The feed conduit may include a feed portion 204 and a
bypass portion 206. The bypass portion may be configured to prevent
overpressurization in hydrogen generation assembly 190. For
example, bypass portion 206 may include a pressure relief valve
208.
[0084] Pump 200 may have any suitable structure configured to
deliver one or more feed and/or fuel streams to the fuel processing
assembly at a plurality of flowrates to fuel processing assembly
194 via, for example, feed conduit 198. For example, pump 200 may
be a variable-speed pump (or a pump that includes a variable speed
motor) that injects the feed and/or fuel streams into the fuel
processing assembly under pressure. The pump may operate at a speed
based on a control signal from the control system.
[0085] Control system 202 may include any suitable structure
configured to control and/or operate pump 200 and/or other
controlled devices of hydrogen generation assembly 190. For
example, control system 202 may include at least one pressure
transducer 210, a control assembly 212, and communication linkages
214. Pressure transducer 210 may be configured to detect pressure
in feed conduit 198. Although pressure transducer 210 is shown to
be adjacent to pump 200 and/or bypass portion 206, the pressure
transducer may be positioned in any suitable portions along the
feed portion.
[0086] Control assembly 212 may include a power supply assembly 216
and a signal conditioner assembly 218. The power supply assembly
may include any suitable structure configured to provide suitable
power to the signal conditioner assembly. For example, the power
supply assembly may include one or more batteries, one or more
solar panels, one or more connectors for connecting to a DC or AC
power source, etc. In some embodiments, power supply assembly 216
may include a DC power supply, which may provide the same voltage
as is required to operate pump 200 and/or pressure transducer
210.
[0087] Signal conditioner assembly 218 may include any suitable
structure configured to condition one or more signals received from
pressure transducer 210 such that one or more of the conditioned
signals may be used to operate pump 200. For example, signal
conditioner assembly 218 may invert the pressure signals (or
transducer signals) received from the pressure transducer and relay
the inverted signals via communication linkages 214 to pump 200.
The inverted signals may be configured to select a speed and/or
flowrate for pump 200 among the plurality of speeds and/or
flowrates for the pump. When the inverted signals are used to
control the pump's speed, the signals may be referred to as "speed
control signals."
[0088] An example of a purge assembly of the hydrogen generation
assemblies described in the present disclosure is shown in FIG. 7
and is generally indicated at 220. The purge assembly may include
any suitable structure configured to purge one or more other
portions of a hydrogen generation assembly. Purge assembly 220 may
be configured to purge one or more gases from reactor(s),
purifier(s), fuel processing assembly(ies), and/or other
component(s) and/or device(s) of hydrogen generation assemblies of
the present disclosure and/or other hydrogen generation assemblies.
For example, purge assembly 220 may include a pressurized gas
assembly 222, a purge conduit 224, and a valve assembly 226. Purge
conduit 224 may be configured to fluidly connect the pressurized
gas assembly and one or more other portions of the hydrogen
generation assembly.
[0089] Pressurized gas assembly 222 may include any suitable
structure configured to connect to and/or receive at least one gas
supply assembly 228. For example, pressurized gas assembly 222 may
include any suitable connectors, piping, valves, and/or other
components configured to connect to and/or receive gas supply
assembly 228. The gas supply assembly may include one or more
containers of pressurized gas (such as one or more cartridges
and/or cylinders) and/or one or more tanks of pressurized gas. The
gas supply assembly may include any suitable pressurized gas
configured to purge one or more other components of the hydrogen
generation assemblies described in the present disclosure. For
example, gas supply assembly may include compressed carbon dioxide
or compressed nitrogen.
[0090] Purge conduit 224 may be configured to fluidly connect the
pressurized gas assembly and one or more other portions of the
hydrogen generation assembly, such as the fuel processing assembly.
The purge conduit may include any suitable connectors, piping,
valves, and/or other components to provide for the fluid connection
between the above assemblies.
[0091] Valve assembly 226 may include any suitable structure
configured to manage flow of the pressurized gas through purge
conduit 224 from pressurized gas assembly 222 to one or more other
portions of the hydrogen generation assembly. For example, valve
assembly 226 may be configured to allow at least one pressurized
gas to flow through the purge conduit from the pressurized gas
assembly to one or more other portions of the hydrogen generation
assembly and/or to prevent the at least one pressurized gas to flow
through the purge conduit from the pressurized gas assembly to one
or more other portions of the hydrogen generation assembly. The
valve assembly may be configured to allow or prevent flow based on
one or more detected variable(s), parameter(s) and/or triggering
event(s). For example, the valve assembly may be configured to
allow flow of at least one pressurized gas from the pressurized gas
assembly to one or more other portions of the hydrogen generation
assembly when power to one or more portions of the hydrogen
generation assembly is interrupted.
[0092] In some embodiments, a control system 230 may control one or
more valves of valve assembly 226. Control system 230 may also
control one or more other components of the hydrogen generation
assembly, or may be dedicated to controlling only purge assembly
220. In some embodiments, valve assembly 226 may be configured to
manage flow in the purge conduit independent of control system 230
and/or any control system of the hydrogen generation assembly. In
other words, valve assembly 226 may be configured to selectively
allow and prevent flow without direction from control system 230
and/or any control system of the hydrogen generation assembly.
[0093] The purge assembly may be located within enclosure or shell
66, external to the shell, or partially within the shell and
partially external the shell. In some embodiments, at least a
portion of the fuel processing assembly may be contained within an
enclosure and at least a portion of the purge assembly may be
contained within the enclosure, as shown in FIG. 1.
[0094] Purge assembly 220 may be connected to any suitable other
component(s) of the hydrogen generation assembly. For example, as
shown in FIG. 2, purge assembly 220 may be connected to the feed
conduit either upstream of heat exchange assembly 136 (such as
shown via purge conduit 224), and/or downstream of the heat
exchange assembly (such as shown via a purge conduit 225). In some
embodiments, the feed conduit of the hydrogen generation assembly
may include a check valve 232 to prevent backflow of the
pressurized gas into the feedstock delivery system, such as when
the pump does not prevent backflow. The pressurized gas from the
purge assembly may exit the hydrogen generation assembly at any
suitable portions, such as the burner and/or the product hydrogen
line.
[0095] Another example of purge assembly 220 is shown in FIG. 8 and
is generally indicated at 232. Purge assembly 232 may include a
pressurized gas assembly 234, a purge conduit 236, and a valve
assembly 238. The pressurized gas assembly may include any suitable
structure configured to receive at least one pressurized gas
container 240 having at least one pressurized gas. Purge conduit
236 may include any suitable structure configured to fluidly
connect pressurized gas assembly 234 and one or more other portions
of the hydrogen generation assembly.
[0096] Valve assembly 238 may include any suitable structure
configured to manage flow of the at least one pressurized gas
through the purge conduit from the pressurized gas assembly to one
or more other portions of the hydrogen generation assembly. For
example, valve assembly 238 may include a manual valve 240 and a
solenoid valve (or purge solenoid valve) 242, as shown in FIG. 8.
The manual valve may be closed to isolate the pressurized gas
assembly from one or more other portions of the hydrogen generation
assembly, such as when installing or connecting a compressed or
pressurized gas canister to the pressurized gas assembly. Manual
valve 240 may then be opened to allow the solenoid valve to manage
flow of the gas through the purge conduit from the pressurized gas
assembly to one or more other portions of the hydrogen generation
assembly. Manual valve 240 may sometimes be referred to as a
"manual isolation valve."
[0097] Solenoid valve 242 may include at least one solenoid or
purge solenoid 244 and at one valve or purge valve 246. The valve
may be configured to move among a plurality of positions, including
between a closed position and an open position. In the closed
position, the pressurized gas assembly is isolated from one or more
other portions of the hydrogen generation assembly and the
pressurized gas does not flow through the purge conduit from the
pressurized gas assembly. In the open position, the pressurized gas
assembly is in fluid communication with one or more other portions
of the hydrogen generation assembly and pressurized gas is allowed
to flow through the purge conduit from the pressurized gas
assembly. Solenoid 244 may be configured to move valve 226 between
the open and closed positions based on one or more detected
variable(s), parameter(s) and/or triggering event(s). Solenoid
valve 242 may, for example, be configured to allow flow of at least
one pressurized gas from the pressurized gas assembly to one or
more other portions of the hydrogen generation assembly when power
to the solenoid and/or one or more portions of the hydrogen
generation assembly is interrupted, such as when power to the fuel
processing assembly is interrupted.
[0098] For example, valve 246 may be configured to be in the open
position without power to solenoid 244 (may also be referred to as
"normally open"), such as via urging of one or more bias elements
or springs (not shown). Additionally, valve 246 may be configured
to be in the closed position with power to solenoid 244 (which may
move the valve to the closed position against urging of the bias
element(s)). Thus, a loss of electrical power to one or more
portions of the hydrogen generation assembly (and/or a loss of
electrical power to solenoid 244) may cause valve 246 to
automatically move from the closed position to the open position.
In other words, valve 246 of solenoid valve 242 may be configured
to be in the closed position when there is power to the solenoid
and/or one or more portions of the hydrogen generation assembly
(such as the fuel processing assembly), and may automatically move
to the open position when power to the solenoid and/or one or more
portions of the hydrogen generation assembly is interrupted.
[0099] In some embodiments, solenoid valve 242 may be controlled by
a control system 248. For example, control system 248 may be
configured to send a control signal to solenoid 244 and the
solenoid may be configured to move valve 246 to the closed position
when the control signal is received. Additionally, valve 246 may be
configured to automatically move to the open position when the
solenoid does not receive a control signal from the control system.
Control system 248 may control one or more other components of the
hydrogen generation assembly or may be separate from any control
system. The solenoid valve may, in some embodiments, be controlled
by both the control system and whether power is supplied to the
solenoid.
[0100] In some embodiments, purge assembly 220 may include a
flow-restriction orifice 250, which may be configured to reduce or
limit flow rate of the pressurized gas discharged from the
pressurized gas assembly. For example, when the pressurized gas is
nitrogen, the flow-restriction orifice may reduce or limit flow
rate of the nitrogen gas to avoid overpressure in one or more other
components of the hydrogen generation assembly, such as in the
reformer and/or purifier. However, when the pressurized gas is
liquefied compressed gas, such as carbon dioxide, the purge
assembly may not include the flow-restriction orifice.
[0101] The purge assemblies of the present disclosure may be used
as part of (or in) any suitable hydrogen generation assembly, such
as a hydrogen generation assembly with a reformer but without a
hydrogen purifier, a hydrogen generation assembly with a hydrogen
purifier but without a reformer, a hydrogen generation assembly
with a methanol/water reformer, a natural gas reformer, a LPG
reformer, etc.
[0102] Another example of hydrogen generation assembly 20 is
generally indicated at 252 in FIG. 9. Unless specifically excluded,
hydrogen generation assembly 252 may include one or more components
of one or more other hydrogen generation assemblies described in
this disclosure. Hydrogen generation assembly 252 may include an
enclosure or shell 254, a hydrogen-producing region 256, a heating
assembly 258, and an exhaust management assembly 260. The enclosure
or shell may include any suitable structure configured to at least
partially contain one or more other components of hydrogen
generation assembly 252 and/or provide insulation (such as thermal
insulation) for those component(s). The enclosure may define an
insulated zone or insulated hot zone 261 for the components within
the enclosure. Enclosure 254 may include at least one exhaust port
262 configured to exhaust gases within the enclosure to the
environment and/or to an exhaust collection system.
[0103] Hydrogen-producing region 256 may be partially or fully
contained within the enclosure. The hydrogen-producing region may
receive one or more feed streams 264 and produce an output stream
266 containing hydrogen gas via any suitable hydrogen-producing
mechanism(s), such as steam reforming, autothermal reforming, etc.
The output stream may include hydrogen gas as at least a majority
component and may include additional gases. When hydrogen
generation assembly 252 is a steam reforming hydrogen generation
assembly, then the hydrogen-producing region may be referred to as
being configured to produce, via a steam reforming reaction, a
reformate stream 266.
[0104] In some embodiments, hydrogen generation assembly 252 may
include a purification region 268, which may include any suitable
structure configured to produce at least one hydrogen-rich (or
permeate) stream 270 from output (or reformate) stream 266 and at
least one byproduct stream 272 (which may contain no or some
hydrogen gas). For example, the purification region may include one
or more hydrogen-selective membranes 274. The hydrogen-selective
membrane(s) may be configured to produce at least part of the
permeate stream from the portion of the reformate stream that
passes through the hydrogen-selective membrane(s), and to produce
at least part of the byproduct stream from the portion of the
reformate stream that does not pass through the hydrogen-selective
membrane(s). In some embodiments, hydrogen generation assembly 252
may include a vaporization region 276, which may include any
suitable structure configured to vaporize the feed stream(s)
containing one or more liquid(s).
[0105] Heating assembly 258 may be configured to receive at least
one air stream 278 and at least one fuel stream 280 and to combust
the fuel stream(s) within a combustion region 282 contained within
enclosure 254. Fuel stream 280 may be produced from the
hydrogen-producing region (and/or the purification region), and/or
may be produced independent of the hydrogen generation assembly.
The combustion of the fuel stream(s) may produce one or more heated
exhaust streams 284. The heated exhaust stream(s) may heat, for
example, hydrogen-producing region 256, such as to at least a
minimum hydrogen-producing temperature. Additionally, the heated
exhaust stream(s) may heat vaporization region 276, such as to at
least a minimum vaporization temperature.
[0106] Exhaust management assembly 260 may include any suitable
structure configured to manage exhaust streams in enclosure 254,
such as heated exhaust streams 284. For example, the exhaust
management assembly may include a sensor assembly 286, a damper
assembly 288, and a control assembly 290, as shown in FIG. 9.
[0107] Sensor assembly 286 may include any suitable structure
configured to detect and/or measure one or more suitable operating
variables and/or parameters in the hydrogen generation assembly
and/or generate one or more signals based on the detected and/or
measured operating variable(s) and/or parameter(s). For example,
the sensor assembly may detect mass, volume, flow, temperature,
electrical current, pressure, refractive index, thermal
conductivity, density, viscosity, optical absorbance, electrical
conductivity, and/or other suitable variable(s), and/or
parameter(s). In some embodiments, the sensor assembly may detect
one or more triggering events.
[0108] For example, sensor assembly 286 may include one or more
sensors 292 configured to detect pressure, temperature, flowrate,
volume, and/or other parameters in any suitable portion(s) of the
hydrogen generation assembly. Sensors 292 may, for example, include
at least one hydrogen-producing region sensor 294 configured to
detect one or more suitable operating variables, parameters, and/or
triggering events in hydrogen-producing region 256. The
hydrogen-producing region sensor may be configured to detect, for
example, temperature in the hydrogen-producing region and/or
generate one or more signals based on the detected temperature in
the hydrogen-producing region.
[0109] Additionally, sensors 292 may include at least one
purification region sensor 296 configured to detect one or more
suitable operating variables, parameters, and/or triggering events
in purification region 268. The purification region sensor may be
configured to detect, for example, temperature in the purification
region and/or generate one or more signals based on the detected
temperature in the purification region.
[0110] Damper assembly 288 may include any suitable structure
configured to manage flow, such as the flow of exhaust gases (or
heated exhaust stream(s) 284), through exhaust port 262. For
example, damper assembly 288 may include at least one damper 298
and at least one actuator 300. The damper may be moveably connected
to exhaust port 262. For example, damper 298 may be slidably,
pivotably, and/or rotatably connected to the exhaust port.
[0111] Additionally, the damper may be configured to move among a
plurality of positions. Those positions may include, for example, a
fully open position 302, a closed position 304, and a plurality of
intermediate open positions 306 between the fully open and closed
positions, as shown in FIGS. 10-12. In the fully open position,
damper 298 may allow one or more exhaust streams 307 (such as
heated exhaust stream(s) 284 and/or other exhaust gases in the
enclosure) to flow through exhaust port 262. In the closed
position, damper 298 may block the exhaust port and prevent exhaust
stream(s) from flowing through the exhaust port. The intermediate
open positions may allow the exhaust stream(s) to flow through
exhaust port 262 at slower rate(s) than when the damper is in the
fully open position. During operation, the temperature in the
hydrogen-producing region may decrease when the exhaust stream(s)
are restricted by the damper.
[0112] Damper 298 may include any suitable structure. For example,
damper 298 may be a gate-type damper with one or more plates that
slide across the exhaust port, such as shown in FIGS. 10-12.
Additionally, damper 298 may be a flapper-type damper, such as
shown in FIG. 9. The flapper-type damper may, for example, include
full circle or half-circle inserts that pivot to open or close the
exhaust. Actuator 300 may include any suitable structure configured
to move damper 298 among the plurality of positions. In some
embodiments, the actuator may move the damper incrementally between
the fully open and closed positions. Although damper assembly 288
is shown to include a single damper and a single actuator, the
damper assembly may include two or more dampers and/or two or more
actuators.
[0113] Control assembly 290 may include any suitable structure
configured to control damper assembly 288 based, at least in part,
on input(s) from sensor assembly 286, such as based, at least in
part, on detected and/or measured operating variable(s) and/or
parameter(s) by the sensor assembly. Control assembly 290 may
receive input(s) only from sensor assembly 286 or the control
assembly may receive input(s) from other sensor assemblies of the
hydrogen generation assembly. Control assembly 290 may control only
damper assembly, or the control assembly may control one or more
other components of the hydrogen generation assembly.
[0114] Control assembly 290 may, for example, be configured to move
damper 298, such as via actuator 300, between the fully open and
closed positions based, at least in part, on the detected
temperature in the hydrogen-producing region and/or the
purification region. When control assembly 290 receives inputs from
two or more sensors, the control assembly may select the input with
a higher value, may select the input with a lower value, may
calculate an average of the input values, may calculate a median of
the input values, and/or perform other suitable calculation(s). For
example, control assembly 290 may be configured to move the damper
toward (or incrementally toward) the closed position when detected
temperature in the hydrogen-producing and/or purification regions
are above a predetermined maximum temperature, and/or to move the
damper toward (or incrementally toward) the fully open position
when the detected temperature in the hydrogen-producing and/or
purification regions are below a predetermined minimum temperature.
The predetermined maximum and minimum temperatures may be any
suitable maximum and minimum temperatures. For example, the maximum
and minimum temperatures may be set based on a desired range of
temperatures for operating the vaporization, hydrogen-producing,
and/or purification regions.
[0115] Another example of hydrogen generation assembly 20 is
generally indicated at 308 in FIG. 13. Unless specifically
excluded, hydrogen generation assembly 308 may include one or more
components of one or more other hydrogen generation assemblies
described in this disclosure. The hydrogen generation assembly may
provide or supply hydrogen to one or more hydrogen consuming
devices 310, such as a fuel cell, hydrogen furnace, etc. Hydrogen
generation assembly 308 may, for example, include a fuel processing
assembly 312 and a product hydrogen management system 314.
[0116] Fuel processing assembly 312 may include any suitable
structure configured to generate one or more product hydrogen
streams 316 (such as one or more hydrogen gas streams) from one or
more feed streams 318 via one or more suitable mechanisms, such as
steam reforming, autothermal reforming, electrolysis, thermolysis,
partial oxidation, plasma reforming, photocatalytic water
splitting, sulfur-iodine cycle, etc. For example, fuel processing
assembly 312 may include one or more hydrogen generator reactors
320, such as reformer(s), electrolyzer(s), etc. Feed stream(s) 318
may be delivered to the fuel processing assembly via one or more
feed conduits 317 from one or more feedstock delivery systems (not
shown).
[0117] Fuel processing assembly 312 may be configured to be
operable among a plurality of modes, such as a run mode and a
standby mode. In the run mode, the fuel processing assembly may
produce or generate the product hydrogen stream(s) from the feed
stream(s). For example, in the run mode, the feedstock delivery
system may deliver the feed stream to the fuel processing assembly
and/or may perform other operation(s). Additionally, in the run
mode, the fuel processing assembly may receive the feed stream, may
combust the fuel stream via the heating assembly, may vaporize the
feed stream via the vaporization region, may generate the output
stream via the hydrogen producing region, may generate the product
hydrogen stream and the byproduct stream via the purification
region, and/or may perform other operations.
[0118] In the standby mode, fuel processing assembly 312 may not
produce the product hydrogen stream(s) from the feed stream(s). For
example, in the standby mode, the feedstock delivery system may not
deliver the feed stream to the fuel processing assembly and/or may
not perform other operation(s). Additionally, in the standby mode,
the fuel processing assembly may not receive the feed stream, may
not combust the fuel stream via the heating assembly, may not
vaporize the feed stream via the vaporization region, may not
generate the output stream via the hydrogen producing region, may
not generate the product hydrogen stream and the byproduct stream
via the purification region, and/or may not perform other
operations. The standby mode may include when the fuel processing
assembly is powered down or when there is no power to the fuel
processing assembly.
[0119] In some embodiments, the plurality of modes may include one
or more reduced output modes. For example, fuel processing assembly
312 may produce or generate product hydrogen stream(s) 316 at a
first output rate when in the run mode (such as at a maximum output
rate or normal output rate), and produce or generate the product
hydrogen stream(s) at second, third, fourth, or more rates that are
lower (or higher) than the first rate when in the reduced output
mode (such as at a minimum output rate).
[0120] Product hydrogen management system 314 may include any
suitable structure configured to manage product hydrogen generated
by fuel processing assembly 312. Additionally, the product hydrogen
management system may include any suitable structure configured to
interact with fuel processing assembly 312 to maintain any suitable
amount of product hydrogen available for hydrogen consuming
device(s) 310. For example, product hydrogen management system 314
may include a product conduit 322, a buffer tank 324, a buffer tank
conduit 325, a sensor assembly 326, and a control assembly 328.
[0121] Product conduit 322 may be configured to fluidly connect
fuel processing assembly 312 with buffer tank 324. Buffer tank 324
may be configured to receive product hydrogen stream 316 via
product conduit 322, to retain a predetermined amount or volume of
the product hydrogen stream, and/or to provide the product hydrogen
stream to one or more hydrogen consuming devices 310. In some
embodiments, the buffer tank may be a lower-pressure buffer tank.
The buffer tank may be any suitable size based on one or more
factors, such as expected or actual hydrogen consumption by the
hydrogen consuming device(s), cycling characteristics of the
hydrogen generator reactor, fuel processing assembly, etc.
[0122] In some embodiments, buffer tank 324 may be sized to provide
enough hydrogen for a minimum amount of time of operation of the
hydrogen consuming device(s) and/or for a minimum amount of time of
operation for the fuel processing assembly, such as a minimum
amount of time of operation for the vaporization region,
hydrogen-producing region, and/or purification region. For example,
the buffer tank may be sized for two, five, ten, or more minutes of
operation of the fuel processing assembly. Buffer tank conduit 325
may be configured to fluidly connect buffer tank 324 with hydrogen
consuming device(s) 310.
[0123] Sensor assembly 326 may include any suitable structure
configured to detect and/or measure one or more suitable operating
variables and/or parameters in the buffer tank and/or generate one
or more signals based on the detected and/or measured operating
variable(s) and/or parameter(s). For example, the sensor assembly
may detect mass, volume, flow, temperature, electrical current,
pressure, refractive index, thermal conductivity, density,
viscosity, optical absorbance, electrical conductivity, and/or
other suitable variable(s), and/or parameter(s). In some
embodiments, the sensor assembly may detect one or more triggering
events.
[0124] For example, sensor assembly 326 may include one or more
sensors 330 configured to detect pressure, temperature, flowrate,
volume, and/or other parameters. Sensors 330 may, for example,
include at least one buffer tank sensor 332 configured to detect
one or more suitable operating variables, parameters, and/or
triggering events in the buffer tank. The buffer tank sensor may be
configured to detect, for example, pressure in the buffer tank
and/or generate one or more signals based on the detected pressure.
For example, unless product hydrogen is being withdrawn from the
buffer tank at a flow rate that is equal to, or greater than, the
incoming flow rate into the buffer tank, the pressure of the buffer
tank may increase and the tank sensor may detect the increase of
pressure in the buffer tank.
[0125] Control assembly 328 may include any suitable structure
configured to control fuel processing assembly 312 based, at least
in part, on input(s) from sensor assembly 326, such as based, at
least in part, on detected and/or measured operating variable(s)
and/or parameter(s) by the sensor assembly. Control assembly 328
may receive input(s) only from sensor assembly 326 or the control
assembly may receive input(s) from other sensor assemblies of the
hydrogen generation assembly. Control assembly 328 may control only
the fuel processing assembly, or the control assembly may control
one or more other components of the hydrogen generation assembly.
The control assembly may communicate with the sensor assembly, the
fuel processing assembly, and/or a product valve assembly (further
described below) via communication linkages 333. Communication
linkages 333 may be any suitable wired and/or wireless mechanism
for one- or two-way communication between the corresponding
devices, such as input signals, command signals, measured
parameters, etc.
[0126] Control assembly 328 may, for example, be configured to
operate fuel processing assembly 312 between the run and standby
modes based, at least in part, on the detected pressure in buffer
tank 324. For example, control assembly 328 may be configured to
operate the fuel processing assembly in the standby mode when the
detected pressure in the buffer tank is above a predetermined
maximum pressure, and/or to operate the fuel processing assembly in
the run mode when the detected pressure in the buffer tank is below
a predetermined minimum pressure.
[0127] The predetermined maximum and minimum pressures may be any
suitable maximum and minimum pressures. Those predetermined
pressures may be independently set, or set without regard to other
predetermined pressure(s) and/or other predetermined variable(s).
For example, the predetermined maximum pressure may be set based on
the operating pressure range of the fuel processing assembly, such
as to prevent overpressure in the fuel processing assembly because
of back pressure from the product hydrogen management system.
Additionally, the predetermined minimum pressure may be set based
on the pressure required by the hydrogen consuming device(s).
Alternatively, control assembly 328 may operate the fuel processing
assembly to operate in the run mode within a predetermined range of
pressure differentials (such as between the fuel processing
assembly and the buffer tank and/or between the buffer tank and the
hydrogen consuming device(s)), and in the standby mode when outside
the predetermined range of pressure differentials.
[0128] In some embodiments, product hydrogen management system 314
may include a product valve assembly 334, which may include any
suitable structure configured to manage and/or direct flow in
product conduit 322. For example, the product valve assembly may
allow the product hydrogen stream to flow from the fuel processing
assembly to the buffer tank, as indicated at 335. Additionally,
product valve assembly 334 may be configured to vent product
hydrogen stream 316 from fuel processing assembly 312, as indicated
at 337. The vented product hydrogen stream may be discharged to
atmosphere and/or to a vented product hydrogen management system
(not shown).
[0129] Product valve assembly 334 may, for example, include one or
more valves 336 that are configured to operate between a flow
position in which the product hydrogen stream from the fuel
processing assembly flows through the product conduit and into the
buffer tank, and a vent position in which the product hydrogen
stream from the fuel processing assembly is vented. Valve(s) 336
may be positioned along any suitable portion(s) of the product
conduit prior to the buffer tank.
[0130] Control assembly 328 may be configured to operate the
product valve assembly based on, for example, input(s) from sensor
assembly. For example, the control assembly may direct or control
the product valve assembly (and/or valve(s) 336) to vent the
product hydrogen stream from the fuel processing assembly when the
fuel processing assembly is in the standby mode. Additionally,
control assembly 328 may direct or control product valve assembly
334 (and/or valve(s) 336) to allow the product hydrogen stream to
flow from the fuel processing assembly to the buffer tank when fuel
processing assembly 312 is in the run mode and/or reduced output
mode(s).
[0131] Another example of hydrogen generation assembly 20 is
generally indicated at 338 in FIG. 14. Unless specifically
excluded, hydrogen generation assembly 338 may include one or more
components of one or more other hydrogen generation assemblies
described in this disclosure. The hydrogen generation assembly may
provide or supply hydrogen to one or more hydrogen consuming
devices 340, such as a fuel cell, hydrogen furnace, etc. Hydrogen
generation assembly 338 may, for example, include a fuel processing
assembly 342 and a product hydrogen management system 344. Fuel
processing assembly 342 may include any suitable structure
configured to generate one or more product hydrogen streams 346
(such as one or more hydrogen gas streams) from one or more feed
streams 348 via one or more suitable mechanisms.
[0132] Product hydrogen management system 344 may include any
suitable structure configured to manage product hydrogen generated
by fuel processing assembly 342. Additionally, the product hydrogen
management system may include any suitable structure configured to
interact with fuel processing assembly 342 to maintain any suitable
amount of product hydrogen available for hydrogen consuming
device(s) 340. For example, product hydrogen management system 344
may include a product conduit 349, a buffer tank 352, a buffer tank
conduit 353, a buffer tank sensor assembly 354, a product valve
assembly 355, and a control assembly 356.
[0133] Product conduit 349 may be configured to fluidly connect
fuel processing assembly 342 with buffer tank 352. The product
conduit may include any suitable number of valves, such as check
valve(s) (such as check valve 350), control valve(s), and/or other
suitable valves. Check valve 350 may prevent backflow from the
buffer tank toward the fuel processing assembly. The check valve
may open at any suitable pressures, such as 1 psi or less. Buffer
tank 352 may be configured to receive product hydrogen stream 346
via product conduit 349, to retain a predetermined amount or volume
of the product hydrogen stream, and/or to provide the product
hydrogen stream to one or more hydrogen consuming devices 340.
[0134] Buffer tank conduit 353 may be configured to fluidly connect
buffer tank 352 and hydrogen consuming device(s) 340. The buffer
tank conduit may include any suitable number of valves, such as
check valve(s), control valve(s), and/or other suitable valve(s).
For example, the buffer tank conduit may include one or more
control valves 351. Control valve 351 may allow isolation of the
buffer tank and/or other components of the hydrogen generation
assembly. The control valve may, for example, be controlled by
control assembly 356 and/or other control assembly(ies).
[0135] Tank sensor assembly 354 may include any suitable structure
configured to detect and/or measure one or more suitable operating
variables and/or parameters in the buffer tank and/or generate one
or more signals based on the detected and/or measured operating
variable(s) and/or parameter(s). For example, the buffer tank
sensor assembly may detect mass, volume, flow, temperature,
electrical current, pressure, refractive index, thermal
conductivity, density, viscosity, optical absorbance, electrical
conductivity, and/or other suitable variable(s), and/or
parameter(s). In some embodiments, the buffer tank sensor assembly
may detect one or more triggering events. For example, buffer tank
sensor assembly 354 may include one or more tank sensors 358
configured to detect pressure, temperature, flowrate, volume,
and/or other parameters. Buffer tank sensors 358 may, for example,
be configured to detect pressure in the buffer tank and/or generate
one or more signals based on the detected pressure.
[0136] Product valve assembly 355 may include any suitable
structure configured to manage and/or direct flow in product
conduit 349. For example, the product valve assembly may allow the
product hydrogen stream to flow from the fuel processing assembly
to the buffer tank, as indicated at 359. Additionally, product
valve assembly 355 may be configured to vent product hydrogen
stream 346 from fuel processing assembly 342, as indicated at 361.
The vented product hydrogen stream may be discharged to atmosphere
and/or to a vented product hydrogen management system (not shown)
including discharging vented product hydrogen back to the fuel
processing assembly.
[0137] Product valve assembly 355 may, for example, include a
three-way solenoid valve 360. The three-way solenoid valve may
include a solenoid 362 and a three-way valve 364. The three-way
valve may be configured to move between a plurality of positions.
For example, three-way valve 364 may be configured to move between
a flow position 363 and a vent position 365, as shown in FIGS.
15-16. In the flow position, the product hydrogen stream is allowed
to flow from the fuel processing assembly to the buffer tank, as
indicated at 359. In the vent position, the product hydrogen stream
from the fuel processing assembly is vented, as indicated at 361.
Additionally, the three-way valve may be configured to isolate the
buffer tank from the product hydrogen stream when the valve is in
the vent position. Solenoid 362 may be configured to move valve 364
between the flow and vent positions based on input(s) received from
control assembly 356 and/or other control assembly(ies).
[0138] Control assembly 356 may include any suitable structure
configured to control fuel processing assembly 342 and/or product
valve assembly 355 based, at least in part, on input(s) from buffer
tank sensor assembly 354, such as based, at least in part, on
detected and/or measured operating variable(s) and/or parameter(s)
by the buffer tank sensor assembly. Control assembly 356 may
receive input(s) only from buffer tank sensor assembly 354 and/or
the control assembly may receive input(s) from other sensor
assemblies of the hydrogen generation assembly. Additionally,
control assembly 356 may control only the fuel processing assembly,
only the product valve assembly, only both the fuel processing
assembly and the product valve assembly, or the fuel processing
assembly, product valve assembly and/or one or more other
components of the hydrogen generation assembly. Control assembly
356 may communicate with the fuel processing assembly, the buffer
tank sensor assembly, and the product valve assembly via
communication linkages 357. Communication linkages 357 may be any
suitable wired and/or wireless mechanism for one- or two-way
communication between the corresponding devices, such as input
signals, command signals, measured parameters, etc.
[0139] Control assembly 356 may, for example, be configured to
operate fuel processing assembly 342 among or between the run and
standby modes (and/or reduced output mode(s)) based, at least in
part, on the detected pressure in buffer tank 352. For example,
control assembly 356 may be configured to operate the fuel
processing assembly in the standby mode when the detected pressure
in the buffer tank is above a predetermined maximum pressure, to
operate the fuel processing assembly in one or more reduced output
mode(s) when the detected pressure in the buffer tank is below a
predetermined maximum pressure and/or above a predetermined
operating pressure, and/or to operate the fuel processing assembly
in the run mode when the detected pressure in the buffer tank is
below a predetermined operating pressure and/or predetermined
minimum pressure. The predetermined maximum and minimum pressures
and/or predetermined operating pressure(s) may be any suitable
pressures. For example, the one or more of the above pressures may
be independently set based on a desired range of pressures for the
fuel processing assembly, product hydrogen in the buffer tank,
and/or the pressure requirements of the hydrogen consuming
device(s). Alternatively, control assembly 356 may operate the fuel
processing assembly to operate in the run mode within a
predetermined range of pressure differentials (such as between the
fuel processing assembly and the buffer tank), and in the reduced
output and/or standby mode when outside the predetermined range of
pressure differentials.
[0140] Additionally, control assembly 356 may be configured to
operate the product valve assembly based on, for example, input(s)
from sensor assembly. For example, the control assembly may direct
or control solenoid 362 to move three-way valve 364 to the vent
position when the fuel processing assembly is in the standby mode.
Additionally, control assembly 356 may direct or control the
solenoid to move three-way valve 364 to the flow position when fuel
processing assembly 342 is in the run mode.
[0141] Control assembly 356 may, for example, include a controller
366, a switching device 368, and a power supply 370. Controller 366
may have any suitable form, such as a computerized device, software
executing on a computer, an embedded processor, programmable logic
controller, an analog device, and/or functionally equivalent
devices. Additionally, the controller may include any suitable
software, hardware, and/or firmware.
[0142] Switching device 368 may include any suitable structure
configured to allow controller 366 to control solenoid 362. For
example, the switching device may include a solid-state relay 372.
The solid-state relay may allow controller 366 to control solenoid
362 via power supply 370. For example, when solenoid 362 is
controlled with 24 volts, the solid-state relay may allow
controller 366 to use a voltage signal less than 24 volts (such as
5 volts) to control solenoid 362. Power supply 370 may include any
suitable structure configured to provide power sufficient to
control solenoid 362. For example, power supply 370 may include one
or more batteries, one or more solar panels, etc. In some
embodiments, the power supply may include one or more electrical
outlet connectors and one or more rectifiers (not shown). Although
the solenoid and controller are described to operate at certain
voltages, the solenoid and controller may operate at any suitable
voltages.
[0143] Another example of hydrogen generation assembly 20 is
generally indicated at 374 in FIG. 17. Unless specifically
excluded, hydrogen generation assembly 374 may include one or more
components of one or more other hydrogen generation assemblies
described in this disclosure. The hydrogen generation assembly may
provide or supply hydrogen to one or more hydrogen consuming
devices 376, such as a fuel cell, hydrogen furnace, etc. Hydrogen
generation assembly 374 may, for example, include a fuel processing
assembly 378 and a product hydrogen management system 380. Fuel
processing assembly 378 may include any suitable structure
configured to generate one or more product hydrogen streams 382
(such as one or more hydrogen gas streams) from one or more feed
streams 384 via one or more suitable mechanisms.
[0144] Product hydrogen management system 380 may include any
suitable structure configured to manage product hydrogen generated
by fuel processing assembly 382 and/or interact with fuel
processing assembly 382 to maintain any suitable amount of product
hydrogen available for hydrogen consuming device(s) 376. For
example, product hydrogen management system 380 may include a
product conduit 386, a buffer tank 388, a buffer tank conduit 389,
a tank sensor assembly 390, a product valve assembly 392, and a
control assembly 394.
[0145] Product conduit 386 may be configured to fluidly connect
fuel processing assembly 378 with buffer tank 388. The product
conduit may include a flow portion or leg 395 and a vent portion or
leg 396. Additionally, product conduit 386 may include any suitable
number of valves, such as check valve(s) (such as check valve 397),
control valve(s), and/or other suitable valve(s). Buffer tank 388
may be configured to receive product hydrogen stream 382 via
product conduit 386, to retain predetermined amount(s) or volume(s)
of the product hydrogen stream, and/or to provide the product
hydrogen stream to one or more hydrogen consuming devices 376.
[0146] Buffer tank conduit 389 may be configured to fluidly connect
buffer tank 388 with hydrogen consuming device(s) 376. The buffer
tank conduit may include any suitable number of valves, such as
check valve(s), control valve(s), and/or other suitable valve(s).
For example, the buffer tank conduit may include one or more
control valves 398. Control valve 398 may allow isolation of the
buffer tank and/or other components of the hydrogen generation
assembly. The control valve may, for example, be controlled by
control assembly 394 and/or other control assembly(ies).
[0147] Tank sensor assembly 390 may include any suitable structure
configured to detect and/or measure one or more suitable operating
variables and/or parameters in the buffer tank and/or generate one
or more signals based on the detected and/or measured operating
variable(s) and/or parameter(s). For example, the tank sensor
assembly may detect mass, volume, flow, temperature, electrical
current, pressure, refractive index, thermal conductivity, density,
viscosity, optical absorbance, electrical conductivity, and/or
other suitable variable(s), and/or parameter(s). In some
embodiments, the tank sensor assembly may detect one or more
triggering events. For example, tank sensor assembly 390 may
include one or more tank sensors 400 configured to detect pressure,
temperature, flowrate, volume, and/or other parameters. Tank
sensors 400 may, for example, be configured to detect pressure in
the buffer tank and/or generate one or more signals based on the
detected pressure.
[0148] Product valve assembly 392 may include any suitable
structure configured to manage and/or direct flow in product
conduit 386. For example, the product valve assembly may allow the
product hydrogen stream to flow from the fuel processing assembly
to the buffer tank (as indicated at 401), and/or vent product
hydrogen stream 382 from fuel processing assembly 378 (as indicated
at 403). The vented product hydrogen stream may be discharged to
atmosphere and/or to a vented product hydrogen management system
(not shown).
[0149] Product valve assembly 392 may, for example, include a first
solenoid valve 402 and a second solenoid valve 404. The first
solenoid valve may include a first solenoid 406 and a first valve
408, while the second solenoid valve may include a second solenoid
410 and a second valve 412. As shown in FIGS. 18-19, the first
valve may be configured to move between a plurality of positions,
including a first open position 407 and a first closed position
409. Additionally, the second valve may be configured to move
between a plurality of positions, including a second open position
411 and a second closed position 413.
[0150] When the first valve is in the open position, the product
hydrogen stream is allowed to flow from the fuel processing
assembly to the buffer tank. In contrast, when the first valve is
in the closed position, buffer tank is isolated from the product
hydrogen stream from the fuel processing assembly (or the product
hydrogen stream from the fuel processing assembly is not allowed to
flow to the buffer tank). When the second valve is in the open
position, the product hydrogen stream from the fuel processing
assembly is vented. In contrast, when the second valve is in the
closed position, the product hydrogen stream from the fuel
processing assembly is not vented.
[0151] First solenoid 406 may be configured to move first valve 408
between the open and closed positions based on input(s) received
from control assembly 394. Additionally, second solenoid 410 may be
configured to move second valve 412 between the open and closed
position based on input(s) received from the control assembly.
[0152] Control assembly 394 may include any suitable structure
configured to control fuel processing assembly 378 and/or product
valve assembly 392 based, at least in part, on input(s) from buffer
tank sensor assembly 390, such as based, at least in part, on
detected and/or measured operating variable(s) and/or parameter(s)
by the buffer tank sensor assembly. Control assembly 394 may
receive input(s) only from buffer tank sensor assembly 390 and/or
the control assembly may receive input(s) from other sensor
assemblies of the hydrogen generation assembly. Additionally,
control assembly 394 may control only the fuel processing assembly,
only the product valve assembly, only both the fuel processing
assembly and the product valve assembly, or the fuel processing
assembly, product valve assembly and/or one or more other
components of the hydrogen generation assembly. Control assembly
394 may communicate with the fuel processing assembly, the buffer
tank sensor assembly, and/or the product valve assembly via
communication linkages 393. Communication linkages 393 may be any
suitable wired and/or wireless mechanism for one- or two-way
communication between the corresponding devices, such as input
signals, command signals, measured parameters, etc.
[0153] Control assembly 394 may, for example, be configured to
operate fuel processing assembly 378 between the run and standby
modes (and/or reduced output mode(s)) based, at least in part, on
the detected pressure in buffer tank 388. For example, control
assembly 394 may be configured to operate the fuel processing
assembly in the standby mode when the detected pressure in the
buffer tank is above a predetermined maximum pressure, to operate
the fuel processing assembly in one or more reduced output mode(s)
when the detected pressure in the buffer tank is below a
predetermined maximum pressure and/or above a predetermined
operating pressure, and/or to operate the fuel processing assembly
in the run mode when the detected pressure in the buffer tank is
below a predetermined operating pressure and/or predetermined
minimum pressure. The predetermined maximum and minimum pressures
and/or predetermined operating pressure(s) may be any suitable
pressures. For example, the one or more of the above pressures may
be independently set based on a desired range of pressures for the
fuel processing assembly, the product hydrogen in the buffer tank,
and/or the pressure requirements of the hydrogen consuming
device(s). Alternatively, control assembly 394 may operate the fuel
processing assembly to operate in the run mode within a
predetermined range of pressure differentials (such as between the
fuel processing assembly and the buffer tank and/or between the
buffer tank and the hydrogen consuming device(s)), and in the
reduced output and/or standby mode(s) when outside the
predetermined range of pressure differentials.
[0154] Additionally, control assembly 394 may be configured to
operate the product valve assembly based on, for example, input(s)
from sensor assembly. For example, the control assembly may direct
or control the first and/or second solenoids to move the first
valve in the closed position and/or the second valve in the open
position when the fuel processing assembly is in the standby mode.
Additionally, control assembly 394 may direct or control the first
and/or second solenoids to move the first valve in the open
position and/or the second valve in the closed position when fuel
processing assembly 378 is in the run mode and/or reduced output
mode(s).
[0155] Control assembly 394 may, for example, include a controller
414, a switching device 416, and a power supply 418. Controller 414
may have any suitable form, such as a computerized device, software
executing on a computer, an embedded processor, programmable logic
controller, an analog device, and/or functionally equivalent
devices. Additionally, the controller may include any suitable
software, hardware, and/or firmware.
[0156] Switching device 416 may include any suitable structure
configured to allow controller 414 to control the first and/or
second solenoids. For example, the switching device may include a
solid-state relay 420. Power supply 418 may include any suitable
structure configured to provide power sufficient to control the
first and/or second solenoids.
[0157] Hydrogen generation assemblies of the present disclosure may
include one or more of the following: [0158] A feed assembly
configured to deliver a feed stream to a fuel processing assembly.
[0159] A feed tank configured to contain feedstock for a feed
stream. [0160] A feed conduit fluidly connecting a feed tank and a
fuel processing assembly. [0161] A pump configured to deliver a
feed stream at a plurality of flowrates to a fuel processing
assembly via a feed conduit. [0162] A feed sensor assembly
configured to detect pressure in a feed conduit downstream from a
pump. [0163] A feed sensor assembly configured to generate a signal
based on detected pressure. [0164] A pump controller configured to
select a flowrate from a plurality of flowrates based on detected
pressure. [0165] A pump controller configured to operate a pump at
a selected flowrate. [0166] A pump controller configured to select
a flowrate for a pump based solely on detected pressure. [0167] A
pump controller configured to condition a signal received from a
sensor assembly. [0168] A pump controller configured to invert a
signal received from a feed sensor assembly. [0169] A pump
controller configured to select a flowrate based on a conditioned
signal. [0170] A pump controller configured to select a flowrate
based on an inverted signal. [0171] A fuel processing assembly
configured to receive a feed stream. [0172] A fuel processing
assembly configured to produce a product hydrogen stream from a
feed stream. [0173] A fuel processing assembly configured to be
operable among a plurality of modes. [0174] A fuel processing
assembly configured to be operable among a run mode in which the
fuel processing assembly produces a product hydrogen stream from a
feed stream, and a standby mode in which the fuel processing
assembly does not produce the product hydrogen stream from the feed
stream. [0175] A purge assembly. [0176] A pressurized gas assembly
configured to receive at least one container of pressurized gas
that is configured to purge a fuel processing assembly. [0177] A
purge conduit configured to fluidly connect a pressurized gas
assembly and a fuel processing assembly. [0178] A purge valve
assembly configured to allow at least one pressurized gas to flow
through a purge conduit from a pressurized gas assembly to a
hydrogen generation assembly when power to the hydrogen generation
assembly is interrupted. [0179] A solenoid valve that moves between
a closed position in which at least one pressurized gas does not
flow through a purge conduit from a pressurized gas assembly, and
an open position in which the at least one pressurized gas is
allowed to flow through the purge conduit from the pressurized gas
assembly. [0180] A solenoid valve that is in the closed position
when there is power to a fuel processing assembly. [0181] A
solenoid valve that automatically moves to an open position when
power to a fuel processing assembly is interrupted. [0182] A
solenoid valve configured to move to a closed position when the
solenoid valve receives a control signal. [0183] A solenoid valve
configured to automatically move to an open position when the
solenoid valve does not receive a control signal. [0184] A control
system configured to send a control signal to a solenoid valve.
[0185] An enclosure containing at least a portion of a fuel
processing assembly and at least a portion of a purge assembly.
[0186] An enclosure having an exhaust port. [0187] A
hydrogen-producing region contained within an enclosure. [0188] A
hydrogen-producing region configured to produce, via a steam
reforming reaction, a reformate stream from at least one feed
stream. [0189] A purification region contained within an enclosure.
[0190] A purification region including a hydrogen-selective
membrane. [0191] A purification region configured to produce a
permeate stream comprised of the portion of a reformate stream that
passes through a hydrogen-selective membrane, and a byproduct
stream comprised of the portion of the reformate stream that does
not pass through the membrane. [0192] A reformer sensor assembly
configured to detect temperature within a hydrogen-producing
region. [0193] A reformer sensor assembly configured to detect
temperature in the purification region. [0194] A heating assembly
configured to receive at least one air stream and at least one fuel
stream. [0195] A heating assembly configured to combust at least
one fuel stream within a combustion region contained within an
enclosure producing a heated exhaust stream for heating at least a
hydrogen-producing region to at least a minimum hydrogen-producing
temperature. [0196] A damper moveably connected to an exhaust port.
[0197] A damper configured to move among a plurality of positions.
[0198] A damper configured to move among a fully open position in
which the damper allows a heated exhaust stream to flow through an
exhaust port, a closed position in which the damper prevents the
heated exhaust stream from flowing through the exhaust port, and a
plurality of intermediate open positions between the fully open and
closed positions. [0199] A damper controller configured to move a
damper between fully open and closed positions based, at least in
part, on a detected temperature in a hydrogen-producing region.
[0200] A damper controller configured to move a damper between
fully open and closed positions based, at least in part, on a
detected temperature in at least one of a hydrogen-producing region
and a purification region. [0201] A damper controller configured to
move a damper toward a closed position when a detected temperature
is above a predetermined maximum temperature. [0202] A damper
controller configured to move a damper toward an open position when
a detected temperature is below a predetermined minimum
temperature. [0203] A buffer tank configured to contain a product
hydrogen stream. [0204] A product conduit fluidly connecting a fuel
processing assembly and a buffer tank. [0205] A tank sensor
assembly configured to detect pressure in a buffer tank. [0206] A
product valve assembly configured to manage flow in a product
conduit. [0207] At least one valve that is configured to operate
between a flow position in which a product hydrogen stream from a
fuel processing assembly flows through a product conduit and into a
buffer tank, and a vent position in which the product hydrogen
stream from the fuel processing assembly is vented prior to the
buffer tank. [0208] A three-way solenoid valve. [0209] A first
valve configured to control flow of a product hydrogen stream
between a fuel processing assembly and a buffer tank. [0210] A
first valve configured to move between a first open position in
which a product hydrogen stream flows between a fuel processing
assembly and a buffer tank, and a first closed position in which
the product hydrogen stream does not flow between the fuel
processing assembly and the buffer tank. [0211] A second valve
configured to vent a product hydrogen stream from a fuel processing
assembly. [0212] A second valve configured to move between a second
open position in which a product hydrogen stream is vented, and a
second closed position in which the product hydrogen stream is not
vented. [0213] A control assembly configured to operate a fuel
processing assembly between run and standby modes based, at least
in part, on detected pressure. [0214] A control assembly configured
to operate a fuel processing assembly in a standby mode when
detected pressure in a buffer tank is above a predetermined maximum
pressure. [0215] A control assembly configured to operate a fuel
processing assembly in a run mode when detected pressure in a
buffer tank is below a predetermined minimum pressure. [0216] A
control assembly configured to direct a product valve assembly to
vent a product hydrogen stream from a fuel processing assembly when
the fuel processing assembly is in the standby mode. [0217] A
control assembly configured to move at least one valve to a flow
position when a fuel processing assembly is in a run mode. [0218] A
control assembly configured to move at least one valve to a vent
position when a fuel processing assembly is in a standby mode.
[0219] A control assembly configured to move a first valve to a
first open position and a second valve to a second closed position
when a fuel processing assembly is in a run mode. [0220] A control
assembly configured to move a first valve to a first closed
position and a second valve to a second open position when a fuel
processing assembly is in a standby mode.
INDUSTRIAL APPLICABILITY
[0221] The present disclosure, including hydrogen generation
assemblies, hydrogen purification devices, and components of those
assemblies and devices, is applicable to the fuel-processing and
other industries in which hydrogen gas is purified, produced,
and/or utilized.
[0222] The disclosure set forth above encompasses multiple distinct
inventions with independent utility. While 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 any claim recites "a" or "a first" element or the
equivalent thereof, such claim should be understood to include
incorporation of one or more such elements, neither requiring nor
excluding two or more such elements.
[0223] Inventions embodied in various combinations and
subcombinations of features, functions, elements, and/or properties
may be claimed through presentation of new claims in a related
application. Such 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
the inventions of the present disclosure.
* * * * *