U.S. patent application number 13/538176 was filed with the patent office on 2014-01-02 for method and system for injecting low pressure oxygen from an ion transport membrane into an ambient or super ambient pressure oxygen-consuming process.
This patent application is currently assigned to L'Air Liquide Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude. The applicant listed for this patent is Wei HUANG, Remi Pierre Tsiava, Justin Jian Wang. Invention is credited to Wei HUANG, Remi Pierre Tsiava, Justin Jian Wang.
Application Number | 20140004470 13/538176 |
Document ID | / |
Family ID | 49778492 |
Filed Date | 2014-01-02 |
United States Patent
Application |
20140004470 |
Kind Code |
A1 |
HUANG; Wei ; et al. |
January 2, 2014 |
Method and System for Injecting Low Pressure Oxygen from an Ion
Transport Membrane into an Ambient or Super Ambient Pressure
Oxygen-Consuming Process
Abstract
A stream of sub ambient oxygen from an ion transport membrane is
injected into an ambient pressure or super ambient pressure
oxygen-consuming process through an annular space in between
concentrically disposed inner and outer tubes where a high velocity
gas is injected into the process from the inner tube.
Inventors: |
HUANG; Wei; (Newark, DE)
; Wang; Justin Jian; (Bear, DE) ; Tsiava; Remi
Pierre; (Saint Germain-Les_Corbeil, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HUANG; Wei
Wang; Justin Jian
Tsiava; Remi Pierre |
Newark
Bear
Saint Germain-Les_Corbeil |
DE
DE |
US
US
FR |
|
|
Assignee: |
L'Air Liquide Societe Anonyme pour
l'Etude et l'Exploitation des Procedes Georges Claude
Paris
CA
American Air Liquide, Inc.
Fremont
|
Family ID: |
49778492 |
Appl. No.: |
13/538176 |
Filed: |
June 29, 2012 |
Current U.S.
Class: |
431/11 ; 110/301;
431/12 |
Current CPC
Class: |
Y02E 20/34 20130101;
Y02P 40/55 20151101; C03B 5/2353 20130101; F23L 15/00 20130101;
Y02E 20/348 20130101; Y02P 40/50 20151101; F23L 7/007 20130101;
C01B 13/0251 20130101; C01B 2203/025 20130101; Y02E 20/344
20130101 |
Class at
Publication: |
431/11 ; 431/12;
110/301 |
International
Class: |
F23L 7/00 20060101
F23L007/00; F23L 15/00 20060101 F23L015/00 |
Claims
1. A method for injecting low pressure oxygen from an ion transport
membrane into an ambient or super ambient pressure oxygen-consuming
process, comprising the steps of: feeding a super ambient pressure,
oxygen-containing feed gas to a first ion transport membrane to
produce a sub-ambient pressure first permeate stream essentially
consisting of oxygen and a first non-permeate stream essentially
consisting of oxygen-deficient feed gas, the ion transport membrane
comprising a material that is a hybrid electron/O.sup.2- anion
hybrid conductor; injecting a high velocity gas into the
oxygen-consuming process from an interior of an inner tube, the
high velocity gas having a velocity of at least 80 m/s; and
injecting the sub-ambient pressure first permeate stream into the
oxygen consuming process form an annular space in between the inner
tube and an outer tube concentrically disposed around the inner
tube, the first permeate stream being sucked from the annular space
by the relative vacuum created by expansion of the high velocity
gas from the inner tube, the sub ambient pressure first permeate
stream having a pressure of at least 8000 Pascal.
2. The method of claim 1, wherein the first permeate stream is not
compressed before it is injected into the oxygen-consuming
process.
3. The method of claim 1, further comprising the step of feeding
compressed air to a second ion transport membrane to produce a
super ambient pressure second permeate stream essentially
consisting of oxygen and a super ambient pressure second
non-permeate stream essentially consisting of oxygen-deficient air,
wherein the oxygen-containing feed gas fed to the first ion
transport membrane is the second non-permeate stream and the second
ion transport membrane comprises a material that is a hybrid
electron/O.sup.2- anion hybrid conductor.
4. The method of claim 3, wherein the high velocity gas is the
second permeate stream.
5. The method of claim 4, wherein: the oxygen-consuming process is
an oxy-combustion furnace; and the inner and outer tubes are part
of a burner that also feeds a fuel into oxy-combustion furnace
where it reacts with the first permeate stream and the high
velocity gas.
6. The method of claim 1, wherein: the oxygen-consuming process is
an oxy-combustion furnace; the feed gas is compressed air; and the
high velocity gas comprises a flue gas that is recovered from the
oxy-combustion furnace.
7. The method of claim 1, wherein the oxygen-consuming process is a
combustion space of a boiler, an industrial melting furnace, an
electric arc furnace, a blast furnace, or a partial oxidation
reactor.
8. The method of claim 1, wherein: the oxygen-consuming process is
an oxy-combustion furnace producing flue gas; and the feed gas is
compressed air that has been pre-heated through heat exchange with
the flue gas.
9. A system for consuming oxygen that is received at low pressure
from an ion transport membrane, comprising: a reactor adapted for
consuming oxygen; a first ion transport membrane comprising a
material that is a hybrid electron/O.sup.2- anion hybrid conductor,
the first ion transport membrane having an inlet, a first permeate
stream outlet and a first non-permeate stream outlet; a source of a
gas; an oxygen injection device comprising an outer tube
concentrically disposed around an inner tube, inner tube having an
inlet and outlet, an annular space in between the inner and outlet
tubes having an inlet and outlet, wherein the inlet of the inner
tube is in fluid communication with the gas source, the inlet of
the annular space is in fluid communication with the first permeate
stream outlet, and the outlets of the inner tube and the annular
space are in fluid communication with an interior of the
reactor.
10. The system of claim 9, wherein there is no compressor in fluid
communication between the first permeate stream outlet and the
outer tube inlet.
11. The system of claim 9, further comprising: a compressor having
an air inlet; and a compressed air outlet and a second ion
transport membrane comprising a material that is a hybrid
electron/O.sup.2- anion hybrid conductor, the second ion transport
membrane having an inlet, a second permeate stream outlet and a
second non-permeate stream outlet, the second ion transport
membrane being adapted to permeate oxygen from a feed gas that is
fed to the inlet of the second ion transport membrane, the
non-permeate portion of the feed gas fed to the inlet of the second
ion transport membrane being channelled to the second non-permeate
stream outlet, the permeated oxygen from the second ion transport
membrane being channelled to the second permeate stream outlet,
wherein: the compressed air outlet is in fluid communication with
the inlet of the second ion transport membrane; the inlet of the
first ion transport membrane is in fluid communication with the
second non-permeate stream outlet; and the gas source is the second
permeate stream outlet.
12. The system of claim 11, wherein: the reactor is an
oxy-combustion furnace; and the inner and outer tubes are part of a
burner that is adapted to feed a fuel into the oxy-combustion
furnace where it reacts with oxygen from the first permeate outlet
that is injected from the outlet of the annular space and oxygen
from the second permeate outlet that is injected from the outlet of
the inner tube.
13. The system of claim 9, further comprising a compressor,
wherein: an outlet of the compressor is in fluid communication with
the inlet of the first ion transport membrane; the reactor is an
oxy-combustion furnace; and the gas source is compressed flue gas
that is recovered from the oxy-combustion furnace.
14. The system of claim 9, wherein the reactor is a combustion
space of a boiler, a furnace, an aluminum furnace, a cement kiln,
an electric arc furnace, a blast furnace, or a partial oxidation
reactor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to injection of oxygen from
ion transport membranes.
[0004] 2. Related Art
Oxy-Combustion in Glass Manufacturing Process
[0005] Air-fired glass melting furnaces has been converted to
oxygen-fired technology (i.e., oxy-combustion with oxygen
concentrations in the oxidant of up to 100%) primarily due to
environmental regulations. Oxy-combustion is one of the most
thermally efficient and cost-effective ways to enable glass
manufacturers to meet NOx emissions restrictions. Compared with
air-fired combustion, oxy-combustion has the potential to reduce
NOx emissions by up to 85%.
[0006] Besides the reduction of NOx emissions, the oxy-combustion
has several other significant advantages over traditional air-fired
combustion processes: [0007] the mass and volume of the flue gas
are reduced by .about.75%; [0008] there is less heat loss in the
flue gas due to the reduction of the flue gas volume; [0009] the
size of the flue gas treatment equipment can be significantly
reduced [0010] the flue gas is primarily CO.sub.2, which is
suitable for sequestration; [0011] the separation of pollutants
from CO.sub.2 is easier since the concentration of pollutants in
the flue gas is higher than that produced by air-fired combustion;
[0012] most of the flue gas is condensable, which makes compression
separation an option; [0013] the heat of condensation can be
captured and reused.
[0014] However, economically speaking, oxygen (for use in oxy-fuel
combustion) is costly for glass melting furnaces. The main cost
increase is the separation of oxygen from air using a cryogenic air
separation unit (ASU). This separation process requires a great
deal of energy. For example, in the field of power generation
nearly 15% of the production of a coal-fired power station can be
consumed by the ASU.
[0015] Thus, there is a need for an alternative method of producing
O.sub.2 at relatively low cost for use in oxy-combustion technology
by the glass industry.
[0016] Nevertheless, oxygen generated at high temperatures has the
potential to benefit oxy-combustion processes by reducing the
amount of fuel needed. In comparison to ambient temperature
oxy-combustion, it has been demonstrated that as much as 10% of the
fuel requirement may be reduced if the oxygen is preheated to
550.degree. C. and the natural gas fuel is preheated to 450.degree.
C. Preheating O.sub.2 to a higher temperature could provide an even
greater reduction of the fuel requirement. However, handling pure
O.sub.2 at a temperature higher than 650.degree. C. is very
difficult and there are very few materials that have been shown to
reliably withstand such high temperatures in the O.sub.2 rich
environment.
Ion Transport Membranes
[0017] Ion transport membranes (ITMs) are fabricated from ionic and
mixed-conducting ceramic oxides that conduct oxygen ions at
elevated temperatures of 800-900.degree. C. There are a wide
variety of materials that are suitable for use in ITMs and their
details need not be duplicated herein.
[0018] ITMs are considered desirable for integration with glass
melting furnaces. Because the glass melting furnace flue gas
temperature is roughly 1400.degree. C. at the exit of the
combustion chamber, the thermal energy of the hot flue gas can be
partly recovered through heat transfer with compressed air, which
in turn is used as the feed gas for the ITM. In operation, air is
typically compressed to about 16 bars, heated to 900.degree. C.,
and fed to the ITM. Hot oxygen permeates through the ITM. In order
to provide a suitable driving force across the membrane, the oxygen
partial pressure of the permeate must be kept low. Typically, an
oxygen recovery of 50% to 80% from air is potentially possible.
While the O.sub.2 product is available at 900.degree. C., its
pressure depends upon the degree of recovery from the air feed gas.
The O.sub.2 product may be available at a desirably high pressure
of about 2.2 bar, but at the expense of relatively low recoveries.
At relatively higher recoveries, the O.sub.2 product may only be
available at pressures as low as about 0.5 bar.
[0019] Glass melting furnaces operate at high temperatures and at
pressures a few Pascal above the ambient pressure. O.sub.2
recovered at high temperature and at a relatively high pressure
(i.e., >1.1 bar) from an ITM does not require further preheating
and is suitable for injection into the glass melting furnace (via a
lance or burner). If greater recoveries are desired, the resultant
O.sub.2 is generated at pressures below ambient. There are
difficulties experienced when attempting to inject such low
pressure O.sub.2 into the furnace. Compressing O.sub.2 at
900.degree. C. is considered undesirable due to the significant
material constraints noted above. Cooling the O.sub.2 down then
compressing it is another option, but such an approach will
decrease the energy efficiency.
[0020] Thus, it is an object of the invention to inject oxygen from
an ITM into a high temperature oxygen consuming process at
relatively high recoveries without requiring compression of the
oxygen. It is another object of the invention to inject oxygen from
an ITM into a high temperature oxygen consuming process at
relatively high recoveries without being restricted by the
relatively limited selection of materials that can withstand high
temperature oxygen-rich environments. It is yet another object of
the invention to improve the efficiency of ITMs integrated with
high temperature oxygen consuming processes.
SUMMARY
[0021] There is disclosed a method for injecting low pressure
oxygen from an ion transport membrane into an ambient or super
ambient pressure oxygen-consuming process, comprising the following
steps. A super ambient pressure, oxygen-containing feed gas is fed
to a first ion transport membrane to produce a sub-ambient pressure
first permeate stream essentially consisting of oxygen and a first
non-permeate stream essentially consisting of oxygen-deficient feed
gas, the ion transport membrane comprising a material that is a
hybrid electron/O.sup.2- anion hybrid conductor. A high velocity
gas is injected into the oxygen-consuming process from an interior
of an inner tube, the high velocity gas having a velocity of at
least 80 m/s. The sub-ambient pressure first permeate stream is
injected into the oxygen consuming process form an annular space in
between the inner tube and an outer tube concentrically disposed
around the inner tube, the first permeate stream being sucked from
the annular space by the relative vacuum created by expansion of
the high velocity gas from the inner tube, the sub ambient pressure
first permeate stream having a pressure of at least 8000
Pascal.
[0022] There is also provided a system for consuming oxygen that is
received at low pressure from an ion transport membrane,
comprising: a reactor adapted for consuming oxygen; a first ion
transport membrane comprising a material that is a hybrid
electron/O.sup.2- anion hybrid conductor, the first ion transport
membrane having an inlet, a first permeate stream outlet and a
first non-permeate stream outlet; a source of a gas; and an oxygen
injection device comprising an outer tube concentrically disposed
around an inner tube. The inner tube has an inlet and outlet, an
annular space in between the inner and outlet tubes having an inlet
and outlet. The inlet of the inner tube is in fluid communication
with the gas source, the inlet of the annular space is in fluid
communication with the first permeate stream outlet, and the
outlets of the inner tube and the annular space are in fluid
communication with an interior of the reactor.
[0023] Either of or both of the method and system may include one
or more of the following aspects: [0024] the first permeate stream
is not compressed before it is injected into the oxygen-consuming
process. [0025] compressed air is fed to a second ion transport
membrane to produce a super ambient pressure second permeate stream
essentially consisting of oxygen and a super ambient pressure
second non-permeate stream essentially consisting of
oxygen-deficient air, wherein the oxygen-containing feed gas fed to
the first ion transport membrane is the second non-permeate stream
and the second ion transport membrane comprises a material that is
a hybrid electron/O.sup.2- anion hybrid conductor. [0026] the high
velocity gas is the second permeate stream. [0027] the
oxygen-consuming process is an oxy-combustion furnace. [0028] the
inner and outer tubes are part of a burner that also feeds a fuel
into oxy-combustion furnace where it reacts with the first permeate
stream and the high velocity gas. [0029] the oxygen-consuming
process is an oxy-combustion furnace. [0030] the feed gas is
compressed air. [0031] the high velocity gas comprises a flue gas
that is recovered from the oxy-combustion furnace. [0032] the
oxygen-consuming process is a combustion space of a boiler, an
industrial melting furnace, an electric arc furnace, a blast
furnace, or a partial oxidation reactor. [0033] the
oxygen-consuming process is an oxy-combustion furnace producing
flue gas. [0034] the feed gas is compressed air that has been
pre-heated through heat exchange with the flue gas. [0035] there is
no compressor in fluid communication between the first permeate
stream outlet and the outer tube inlet. [0036] the method or system
further comprises: [0037] a compressor having an air inlet; and
[0038] a compressed air outlet and a second ion transport membrane
comprising a material that is a hybrid electron/O.sup.2- anion
hybrid conductor, the second ion transport membrane having an
inlet, a second permeate stream outlet and a second non-permeate
stream outlet, the second ion transport membrane being adapted to
permeate oxygen from a feed gas that is fed to the inlet of the
second ion transport membrane, the non-permeate portion of the feed
gas fed to the inlet of the second ion transport membrane being
channelled to the second non-permeate stream outlet, the permeated
oxygen from the second ion transport membrane being channelled to
the second permeate stream outlet, wherein: [0039] the compressed
air outlet is in fluid communication with the inlet of the second
ion transport membrane; [0040] the inlet of the first ion transport
membrane is in fluid communication with the second non-permeate
stream outlet; and [0041] the gas source is the second permeate
stream outlet. [0042] the inner and outer tubes are part of a
burner that is adapted to feed a fuel into the oxy-combustion
furnace where it reacts with oxygen from the first permeate outlet
that is injected from the outlet of the annular space and oxygen
from the second permeate outlet that is injected from the outlet of
the inner tube. [0043] the method or system further comprises a
compressor, wherein: [0044] an outlet of the compressor is in fluid
communication with the inlet of the first ion transport membrane;
[0045] the reactor is an oxy-combustion furnace; and [0046] the gas
source is compressed flue gas that is recovered from the
oxy-combustion furnace. [0047] the reactor is a combustion space of
a boiler, a furnace, an aluminum furnace, a cement kiln, an
electric arc furnace, a blast furnace, or a partial oxidation
reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] For a further understanding of the nature and objects of the
present invention, reference should be made to the following
detailed description, taken in conjunction with the accompanying
drawings, in which like elements are given the same or analogous
reference numbers and wherein:
[0049] FIG. 1 is a schematic of the invention with one ITM.
[0050] FIG. 2 is a schematic of the invention with two ITMs.
[0051] FIG. 3 is a CFD simulation of an embodiment of the
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] In this invention, sub ambient pressure oxygen that is
permeated from an ion transport membrane is injected into an
oxygen-consuming process from an oxygen injection device. The
oxygen injection device comprises an outer tube concentrically
disposed around an inner tube. The outlet of the inner tube and an
outlet of an annular space in between the inner and outer tubes
feed into an interior of a reactor in which the oxygen-consuming
process takes place. A high velocity gas is injected into the
reactor from the inner tube. Expansion of the high velocity gas at
the outlet of the inner tube causes oxygen to be sucked from the
annular space and, hence, sucked from the ion transport
membrane.
[0053] The reactor containing the oxygen-consuming process is not
limited. Typical types of reactors include oxy-combustion furnaces,
oxy-combustion boilers, aluminum furnaces, cement kilns, electric
arc furnaces having oxygen lances or oxy-combustion burners,
industrial melting furnaces, and blast furnaces. The industrial
melting furnace is typically a furnace in which glass, metal, or
vitrifiable material such as a ceramic or frit.
[0054] The ion transport membrane is made of a material that
includes a densified separation layer made of a hybrid
electron/O.sup.2- anion hybrid conductor. The densified separation
layer is otherwise gas-tight. Such materials are well known and
their details need not be duplicated herein.
[0055] An oxygen-containing feed gas (that is fed to an inlet of
the ion transport membrane) is similarly not limited. Typically,
the feed gas is compressed air, oxygen-deficient air, or an
oxygen-containing gas derived from a high temperature, industrial
process such as a glass furnace or blast furnace. At least some of
the oxygen from the oxygen-containing feed gas permeates through
the membrane and exits the membrane at a permeate outlet. The
non-permeate portion of the oxygen-containing feed gas (now termed
oxygen-deficient feed gas) exits the membrane at a non-permeate
outlet. The feed gas is at a temperature high enough to maintain
the temperature of the hybrid O.sup.2- anion and electron conductor
material so that oxygen may permeate across the membrane.
Typically, the feed gas is at a temperature of about 900.degree. C.
The feed gas is also at a pressure suitably high to generate a
driving force across the membrane that drives permeation of oxygen
across the membrane. Typically the feed gas is at a pressure of
about 16 bar.
[0056] The permeate from the membrane is at sub ambient pressure.
Rather than compress the permeate in order to inject the permeate
into the reactor, it is sucked into the reactor by the creation of
a low pressure region adjacent the outlet of the inner tube and the
outlet of the annular space that results from the expansion of the
high velocity gas at the outlet of the inner tube. In this manner,
oxygen that would otherwise not be able to be injected into the
reactor (or injected only if it was compressed) may be injected
into the reactor. As a result, higher recoveries of oxygen from the
feed gas are realized. The gas pressure of the permeate should be
8000 Pascal or higher. If the pressure of the permeate is too low,
it will not be able to be sucked into the reactor via the annular
space.
[0057] The high velocity gas is also not limited. Typical examples
include oxygen, flue gas, gaseous fuel, particulate solid fuel
fluidized with a conveying gas such as air, or other industrial gas
derived from a high temperature, industrial process such as a blast
furnace or a partial oxidation reactor/gasifier. The high velocity
gas is injected from the inner tube at a velocity sufficient to
cause the oxygen to be sucked from the annular space. Typically,
the velocity is at least 80 m/s or about 130-140 m/s.
[0058] The oxygen injection device may extend through a wall of the
reactor so that the downstream ends of the inner and outer tubes
are disposed within the reactor or their downstream ends may be
flush with a wall of the reactor. The inner diameter of the outer
pipe should only be a few mm larger than the outer diameter of the
inner pipe in order to create the low pressure region at the outlet
of the annular space. If the gap between the inner and outer pipes
is too large, a high pressure zone will appear adjacent the inner
surface of the outer pipe and a low pressure zone appear adjacent
the outer surface of the inner pipe. In such a situation, the flue
gas will recirculate at the interface of the oxygen injection
device and the wall of the reactor into which it extends and the
oxygen in the annular space will not be sucked into the reactor.
Because the annular space is limited by the gap, the mass flow rate
of oxygen sucked into the reactor is similarly limited. Therefore,
a plurality of the oxygen injection devices might be necessary when
a relatively large mass flow rate of oxygen needs to be sucked into
the reactor from the combined annular spaces.
[0059] The suction rate (the mass flow rate of the oxygen sucked
from the annular space divided by the mass flow rate of the high
velocity gas) is dependent upon the velocity of the high velocity
gas in the inner pipe and also upon the thickness of the gap
between the inner and outer pipes. The suction rate increases when
the velocity of the high velocity gas in the inner pipe increases.
If the velocity of high velocity gas in the inner pipe is
relatively low, the inner diameter of the outer pipe should be
reduced in order to keep the same suction ratio in the gases from
the outer pipe. In one embodiment, the device has seven
pipe-in-pipe structures. HP O.sub.2 flows at high velocity (130-140
m/s) in the inner pipe of each structure. O.sub.2 at sub-atmosphere
of ITM system connected to the outer pipes. As the HP O.sub.2 flush
out of the inner pipe at high speed, a negative pressure is created
at the joint area of the outer pipe and furnace wall, and thus the
HT/LP O.sub.2 can be sucked into the flow stream.
[0060] The oxygen injection device can be used for a wide variety
of purposes. It can be used as a burner or lance whereby the high
velocity gas is oxygen. It can instead be used as a gas mixer for a
high pressure gas (the high velocity gas) and a low pressure gas
(the oxygen permeate at sub ambient pressure).
[0061] In one embodiment and as best shown in FIG. 1, there is only
one ion transport membrane 1 (the first ion transport membrane) 1.
The feed gas 3 is either compressed air or an oxygen-containing gas
at super ambient pressure that is derived from a high temperature
industrial process. Oxygen permeates across the first ion transport
membrane 1 and exits as a first permeate stream 5 at a first
permeate stream outlet. The portion of the feed gas 3 that does not
permeate across the first ion transport membrane 1 exits as a first
non-permeate stream 7 at a first non-permeate stream outlet.
Optionally, the first non-permeate stream 7 may be used as the high
velocity gas 9 if it is at a sufficiently high pressure, in which
case the first non-permeate outlet is the source of the high
velocity gas 9. The high velocity gas 9 is injected from the inner
tube 11 and into an interior of the reactor (not shown) where the
oxygen-consuming process occurs. The first permeate stream 5 is
injected from an annular space 13 between the inner tube 11 and
outer tube 15.
[0062] In another embodiment and as best illustrated in FIG. 2,
there are two ion transport membranes 21, 22 in series. Compressed
air 23 from the outlet of a compressor (not shown) is fed to the
inlet of one of the ion transport membranes (the second ion
transport membrane 22). Oxygen permeates across the second membrane
22 and exits as a second permeate stream 24 at a second permeate
stream outlet. The second permeate outlet is in fluid communication
with the inlet of the inner tube 25 so that the stream of second
permeate (which is at super ambient pressure) is the high velocity
gas. The remaining portion of the air (which has not permeated
across the second membrane 22) exits the second membrane 22 as a
second non-permeate stream 26 at a second non-permeate stream
outlet. The second non-permeate 26 is oxygen-deficient air. The
second non-permeate 26 (which is also at super ambient pressure) is
fed to the inlet of the other ion transport membranes (the first
ion transport membrane 21). Oxygen from the second non-permeate
permeates 26 across the first membrane 21 and exits as a first
permeate stream 27 from a first permeate stream outlet. The first
permeate stream outlet is in fluid communication with an inlet of
the annular space 28 of the oxygen injection device so that the
first permeate stream 27 is sucked from the first membrane 21 and
the annular space 28 and injected into the reactor from the outlet
of the annular space 28. The remaining portion of the second
non-permeate stream (which has not permeated across the first
membrane 21) exits the first membrane 21 as a first non-permeate
stream 29 at a first non-permeate stream outlet. The first
non-permeate stream 29 ordinarily is quite low in oxygen and may be
used for any purpose requiring a low oxygen or high nitrogen
gas.
Prophetic Examples
[0063] CFD (Computational fluid dynamics) simulations have been
conducted to calculation the amount of HT/LP O2 that can be sucked
in by the HT/HP O.sub.2 flow stream by a device having seven
pipe-in-pipe structures. The flow rates of the O.sub.2 through the
inner pipes and outer pipes, the inlet velocity of the O.sub.2 in
the inner pipes, the pressure of the LP O.sub.2, and the resultant
suction ratios are listed in Table 1. The suction ratio by this
design is pretty high, ranging from 15% to 56.4% depending on the
pressure of the LP O.sub.2. Table 2 shows the O.sub.2 suction ratio
when the inner oxygen flow velocity is varied. As seen in Table 2,
the O.sub.2 suction ratio increases if increasing the O.sub.2 flow
velocity. FIG. 3 shows a simulation with seven pipe-in-pipe oxygen
injectors. Thus, the CFD simulation proves the efficiency of the
novel design.
TABLE-US-00001 TABLE 1 CFD simulations of O.sub.2 suction ratio
with different inner pipe pressure Pressure of O.sub.2 flow rate
Inlet LP O.sub.2 O.sub.2 flow rate of the inner velocity of
(relative of the outer Suction pipe inner pipe to 1 atm) pipes
Ratio Case (kg/s) (m/s) (Pascal) (kg/s) (%) 1 0.14 (0.02 .times. 7)
136 0 0.079 56.4 2 0.14 (0.02 .times. 7) 136 -1000 0.047 33.6 3
0.14 (0.02 .times. 7) 136 -1500 0.032 22.9 4 0.14 (0.02 .times. 7)
136 -2000 0.021 15.0
TABLE-US-00002 TABLE 2 CFD simulations of O2 suction ratio with
different inner oxygen flow velocity Inlet O.sub.2 flow rate
velocity Pressure of O.sub.2 flow rate of the inner of inner LP
O.sub.2 (relative of the outer Suction pipe pipe to 1 atm) pipes
Ratio Case (kg/s) (m/s) (Pascal) (kg/s) (%) 2 0.14 136 -1000 0.047
33.6 (0.02 .times. 7) 5 0.10 97 -1000 0.016 16.0 (0.014286 .times.
7) 6 0.08 78 -1000 0 0 (0.011428 .times. 7)
[0064] Preferred processes and apparatus for practicing the present
invention have been described. It will be understood and readily
apparent to the skilled artisan that many changes and modifications
may be made to the above-described embodiments without departing
from the spirit and the scope of the present invention. The
foregoing is illustrative only and that other embodiments of the
integrated processes and apparatus may be employed without
departing from the true scope of the invention defined in the
following claims.
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