Patent Grant
11710845
The present disclosure relates generally to thermodynamic processing, and more particularly, to systems, devices, and methods employing electrochemical processing (e.g., pumping, transport, compression, or expansion) with oxygen as carrier gas.
Embodiments of the disclosed subject matter convey a fluid, such as but not limited to carbon dioxide (CO2) or water vapor (H2O), across a membrane of an electrochemical module using oxygen (O2) as a carrier gas. The electrochemical module combines the fluid with O2 and electrons (e) to form an anion of the fluid and transports the anions through an anion exchange membrane. The anion exchange membrane is disposed between opposing electrodes, which may include respective catalysts that facilitate the reaction of the fluid with the oxygen carrier gas. The electrochemical module employing O2 as the carrier gas can be used in a variety of applications, including, but not limited to, compressing or expanding fluid in a heating/cooling system (e.g., vapor compression cycle) or power generation system (e.g., organic Rankine cycle or Brayton cycle), or removing the fluid from an air flow or flue gas flow (e.g., for CO2 capture, regeneration of stale air, or dehumidification).
In one or more embodiments, a system comprises an electrochemical module. The electrochemical module comprises an anion exchange membrane, a first electrode, and a second electrode. The first electrode is on an inlet side of the anion exchange membrane, and the second electrode is on an outlet side of the anion exchange membrane. The outlet side is opposite the inlet side. The electrochemical module is constructed to transport a fluid from the inlet side to the outlet side of the anion exchange membrane, in the presence of an electric field applied between the first and second electrodes, via a combination of the fluid with a carrier gas. The carrier gas comprises O2.
In one or more embodiments, a method comprises applying an electric field between first and second electrodes. The first electrode is on an inlet side of an anion exchange membrane of an electrochemical module. The second electrode is on an outlet side of the anion exchange membrane. The outlet side is opposite the inlet side. The method further comprises, at the inlet side of the anion exchange membrane, combining a fluid and a carrier gas. The method also comprises, in the presence of the applied electric field, transporting the combined fluid and carrier gas through the anion exchange membrane to the outlet side, and, at the outlet side of the anion exchange membrane, dissociating the transported combination back to the fluid and carrier gas. The carrier gas comprises O2.
Objects and advantages of embodiments of the disclosed subject matter will become apparent from the following description when considered in conjunction with the accompanying drawings.
Embodiments will hereinafter be described with reference to the accompanying drawings, which have not necessarily been drawn to scale. Where applicable, some elements may be simplified or otherwise not illustrated in order to assist in the illustration and description of underlying features. Throughout the figures, like reference numerals denote like elements.
Embodiments of the disclosed subject matter relate to electrochemical transport of a fluid across a membrane by using oxygen (O2) as a carrier gas. For example, the fluid can comprise carbon dioxide (CO2), water vapor (H2O), or any other compound capable of combining with O2 and electrons to form an anion. Using a combination of the O2 with the fluid, an electric field applied across the membrane transports the combination through the membrane, which transport may be used to accomplish one or more pressure processes (i.e., compression or expansion) of a heating/cooling system (e.g., a vapor compression cycle) or power generation system (e.g., an organic Rankine cycle or Brayton cycle), to isolate a particular component in an inlet gas flow (i.e., reducing CO2 content in an exhaust gas or stale air, or reducing water vapor in conditioned air), or for any other purpose. In some embodiments, the transport of the combination through the membrane may generate an electric field.
For example, in a fabricated embodiment, the electrodes were formed of CaRuO3 and attached to opposing surfaces of the AEM. KMnO4 was used as a strong oxidizing agent and mixed with 1M KOH solution to prepare 1 mM potassium permanganate solution. CaO and RuCl3 were mixed in a 1:1 molar ratio and dissolved in the potassium permanganate solution. The solution was placed in a stainless-steel reaction vessel and heated to 200° C. for 48 hours. The resulting precipitated product was washed with de-ionized (DI) water and ethanol and dried overnight at 80° C. The AEM was pre-treated by ion exchanging from Cl− state to CO32− state by soaking in Na2CO3 solution for 24 hours. An ink of the catalyst was prepared by mixing CaRuO3 with 5% ionomer solution in isopropanol, which solution was then sonicated for 30 mins to form an ink suspension. The ink solution in suspension form was brushed on the surface of carbon cloth, with loading amount of 5 mg/cm2, in order to form anode and cathode electrodes. The prepared electrodes were then pressed against the AEM with pound force of 500 psi to couple the electrodes to the AEM. Other fabrication processes for forming the electrodes and/or AEM are also possible according to one or more contemplated embodiments.
The assembly of the electrodes 106, 110 to AEM 108 can be considered an integral membrane electrode assembly (MEA) 102 and can be separately coupled to gas inlet distribution manifold 104 (i.e., suction-side or feed-side volume) and gas outlet distribution manifold 112 (i.e., discharge-side volume) to convey fluid and/or O2 carrier gas to/from the AEM 108. In some embodiments, the MEA 102 can include additional support structures, such as stainless-steel mesh, between the electrodes and the adjacent manifold, to bolster the AEM 108 against high pressures generated at the discharge side by the transport of the fluid through the AEM 108. DC voltage source 114, connected to the electrodes 106, 110, can apply an electric field to the AEM 108 to drive transport of the fluid, in particular, the ionic form of the fluid, therethrough.
Referring to
The O2 carrier gas 154 can be part of the cathode 106 (e.g., absorbed within a material of the electrode, as explained in further detail below) or externally supplied to the cathode 106, for example, separate from the fluid (e.g., via a separate inlet to the inlet manifold 104) or as part of the fluid supplied to the inlet manifold (e.g., where the gas or air flow includes CO2 or H2O as well as O2).
At the cathode 106, interaction with the catalyst causes a reaction between the fluid, 152, O2 carrier gas 154, and electrons 158 (e.g., from voltage source 114) to form the fluid anion 156. For example, when the fluid is CO2 and the catalyst is Pt, the catalyst-facilitated reactions at the cathode 106 to form the corresponding fluid anion, HCO3−, are given by:
O2+2H2O+4e−→4OH−
4OH−+4CO2→4HCO3− (1)
In another example, when the fluid is CO2 and the catalyst is CaRuO3, the catalyst-facilitated reaction at the cathode 106 to form the corresponding fluid anion, CO32−, is given by:
2CO2+O2+4e−→2CO32− (2)
In another example, when the fluid is H2O, the catalyst-facilitated reaction at the cathode 106 to form the corresponding fluid anion, OH−, is given by:
2H2O+O2+4e−→4OH− (3)
The process 700 can proceed to 704, where voltage source 114 applies an electric field to the cathode 106 and anode 110 of the MEA 102, such that, at 706, the fluid anion 156 is transported from the cathode 106 side through AEM 108 to the anode 110 side. In the transport 706, the O2 gas serves as a carrier for the fluid. The fluid in the ionic form (i.e., the anion 156) can move freely in the AEM 116 via an ion hopping mechanism. For example, the anion 156 can attach to carbonate functional groups in AEM 116 and can readily hop from one carbonate functional group to another carbonate functional group, driven by the DC voltage potential supplied by power supply 114.
At the anode 110, the catalyst facilitates dissociation of the transported fluid anion 166 at 708 to reform the constituent fluid and O2 carrier gas. For example, when the fluid is CO2 and the catalyst is Pt, the catalyst-facilitated reactions at the anode 110 are given by:
4HCO3−→4OH−+4CO2
4OH−→O2+2H2O+4e− (4)
In another example, when the fluid is CO2 and the catalyst is CaRuO3, the catalyst-facilitated reaction at the anode 110 is given by:
2CO32−→2CO2+O2+4e− (5)
In another example, when the fluid is H2O, the catalyst-facilitated reaction at the anode 110 is given by:
4OH−→2H2O+O2+4e− (6)
In essence, 708 is the reverse process of 702, with electrons 168 being released from the dissociating anion 166 to regenerate the O2 gas 164 and the fluid 162.
If the fluid flow to the inlet manifold 104 and the fluid flow from the outlet manifold 112 are regulated (e.g., when electrochemical module 100 operates as a compressor), the resulting fluid 162 at the discharge-side can be at a higher pressure. The resulting fluid 162 in outlet manifold 112 can then be conveyed at 710 for further processing (e.g., chemical or electrochemical modification for storage), waste disposal (e.g., discharge to a volume external to a conditioned space) and/or use (e.g., as the input to a heat exchanger or as a source of water). At 712, it can be determined if the process 700 should be repeated, for example, as part of a heating/cooling or power generation cycle or any other cycle, in which case the process 700 returns to 702.
Although 702-712 are illustrated separately in
As referenced above, in some embodiments, the O2 carrier gas may be provided to the inlet manifold 104 separately from the fluid or as part of the fluid (i.e., an air mixture including CO2 and O2, or H2O and O2). In other embodiments, the electrochemical module 100 can be constructed to restrict O2 from circulating outside of the MEA 102. For example, the cathode 106 and the anode 110 can include an oxygen-absorbing material, such as LaMnO3 perovskite. At the cathode 106, the oxygen-absorbing material can store O2 therein and can release as O2 gas 154 for combination with the fluid 152. Similarly, at the anode 110, the oxygen-absorbing material can receive O2 gas 164 from the dissociation of anion 166 and store the O2 therein. As a result, the O2 gas only migrates within the MEA 102. Once the oxygen-absorbing electrodes have been expended (i.e., when the cathode 106 has released all of its stored O2 or when the anode 110 has reached its capacity for storing O2), the electrodes can be regenerated, such as by reversing the flow through the electrochemical module 100, for example, as described below with respect to
The electrochemical transport process 150 uses energy in the form of a voltage charge (and corresponding current) supplied by the power supply 114. As a result, the electrochemical module 100 may be heated, which in turn may increase a temperature of the fluid 162. This increased temperature of the discharged, compressed fluid 162 can be undesirable in some applications, for example, when the module 100 serves as compressor of a vapor compression cycle. Thus, in some embodiments, heat 116 may be removed by cooling the module 100 and/or the resulting fluid output. As compared to conventional mechanical compressors, the electrochemical compressor 110 has relatively large surface areas (e.g., of AEM 108) for passive cooling.
Alternatively or additionally, heat 116 can be removed from the MEA 102 and/or the discharge fluid 162 via active cooling to yield a substantially temperature-controlled compression process 150. In some embodiments, the active cooling can yield a temperature for the fluid discharge 162 that has been chosen to maximize system performance (or to at least improve performance of the system). For example, the discharge may have a temperature value slightly higher than that of a subsequent heat exchanger (e.g., condenser in a vapor compression system). For example, heat 116 can be removed by heat exchangers thermally coupled to the outlet manifold 112. Such a heat exchanger can be an open channel heat exchanger (e.g., where a cooling air is flowed through a channel in or adjacent to channels in the outlet manifold 112), a microchannel flat tube array thermally coupled to the outlet manifold 212 and/or the MEA 102 (e.g., which can use higher density fluid than air), a metal foam heat exchanger thermally coupled to the outlet manifold 212 and/or the MEA 102, or any other type of heat exchanger setup.
As noted above, the transport of the combination of O2 and fluid through the membrane can be used to generate an electric field. For example, such transport may be driven by a pressure gradient between the inlet and outlet sides of the membrane.
In effect, operation of electrochemical module 200 is the reverse process of the operation of electrochemical module 100 described above with respect to
In some embodiments, the electrochemical module 200 may be the same device as electrochemical module 100 but operating in a reverse flow direction with opposite polarity. Thus, heat 216 can be removed in a manner similar to that described above for electrochemical module 100. Moreover, electrodes 206, 210 may be constructed to retain O2 carrier gas within MEA 202 in a manner similar to that described above for electrochemical module 100.
Referring to
At the anode 206, interaction with the catalyst facilitates a reaction between the electrons, fluid, and O2 carrier gas to form the fluid anion 256. The process 750 can proceed to 754, where the anion 256 is transported from the anode 206 side through AEM 208 to the cathode 210 side, for example, by a pressure gradient across the AEM 208. The transport of fluid anion 256 can generate an electric field (i.e., DC power). At 756, it is determined whether the generated power is to be used at 758 (e.g., to power another component of the system, such as electrochemical module 100) or to be stored at 760 (e.g., by charging a battery). At the cathode 210, the catalyst facilitates dissociation of the transported fluid anion 266 at 762 to reform the constituent fluid, O2 carrier gas, and electrons. In essence, 762 is the reverse process of 752, with electrons 668 released from anion 266 to regenerate the O2 gas 264 and fluid 262.
If the fluid flow to the inlet manifold 204 and the fluid flow from the outlet manifold 212 is regulated, the resulting fluid 262 at the discharge-side can be at a lower pressure. The resulting low-pressure fluid 262 in outlet manifold 212 can then be conveyed for further processing and/or use at 766, for example, as the input to a subsequent heat exchanger. At 766, it can be determined if the process 750 should be repeated, for example, as part of a heating/cooling or power generation cycle, in which case the process 750 returns to 752.
Although 752-766 are illustrated separately in
Thus, an electrochemical module employing O2 carrier gas can be constructed for fluid capture, fluid compression, and/or fluid expansion (and potential power recovery). In some embodiments, the electrochemical module can be constructed to be switchable between a first mode where a voltage is applied to the electrochemical module, the MEA has a first polarity, and fluid flow is in a first direction (e.g., a compression mode), and a second mode where a voltage is generated by the electrochemical module, the MEA has a second polarity opposite the first, and fluid flow is in a second direction opposite the first (e.g., an expansion mode). Regardless of the operational configuration, the electrochemical module may have a similar device construction.
For example,
An opposing end plate 312 with one or more channels 320 therein can serve as a second gas distribution manifold (inlet or outlet manifold depending on operation of cell 300). Layout and/or geometry of channel(s) 320 can be substantially the same or differ across end plate 312. Moreover, layout and/or geometry of channel(s) 320 of end plate 312 can be substantially the same as the layout and/or geometry of channel(s) 318 of end plate 304, for example, when device 300 is constructed to reverse fluid flow to switch between first and second modes. Alternatively, layout and/or geometry of channel(s) 320 of end plate 312 can differ from the layout and/or geometry of channel(s) 318 of end plate 304. An inlet/outlet face of end plate 312 can face electrode 310 such that channel(s) 320 are in fluid communication with MEA 302. A sealing gasket 316 can be disposed between end plate 312 and MEA 302 to prevent leakage of fluid and/or O2 from device 300.
The inlet/outlet face of end plate 304 may also be in electrical contact with electrode 306. Similarly, the inlet/outlet face of end plate 312 may be in electrical contact with electrode 310. Thus, the electric field can be applied to electrodes 306, 310 (and thus AEM 308) via end plates 304, 312, respectively. Alternatively, respective electrical connections may be routed through end plates 306, 312, through gaskets 314, 316, or through a portion of MEA 302 so as to apply the electric field to respective electrodes 306, 310 without directly energizing manifolds 304, 312.
The gas distribution manifolds 304, 312 may be formed of a material substantially resistant to degradation to electricity and/or the chemistry present during operation of the electrochemical device 300. Moreover, the manifolds 304, 312 may be constructed to resist the fluid pressures generated during operation and/or to conduct electricity and/or heat. For example, the manifolds 304, 312 may be constructed of graphite or stainless steel, although other materials are also possible according to one or more contemplated embodiments. When the fluid is CO2, the use of stainless steel for the manifolds may be preferable over graphite in order to avoid corrosion.
Within each gas distribution manifold, the channel layout and/or geometry can be designed to account for pressure and fluid flow variations. For example,
Similarly,
The discussion above has focused on a single electrochemical cell. However, the flow rate of fluid through a single electrochemical cell may be insufficient for practical embodiments. Thus, in some embodiments, multiple electrochemical unit cells (whether compressor, expander, switchable compressor/expander, or fluid capture module) can be coupled together (serially or in parallel) to form an electrochemical module stack. In this way, the flow rate can be increased and/or the desired pressure lift across the compressor can be achieved.
For example,
For example, each transfer manifold 402a, 402b can be a combination of an outlet manifold (e.g., end plate 370 in
As noted above, the power consumed in the electrochemical compression can generate heat, which may affect performance of the vapor compression cycle. Thus, in embodiments, the generated heat may be removed, for example, by including cooling elements in the transfer manifolds 402a-402b and/or outlet manifold 112c. For example, when the transfer manifold 402a, 402b is configured as a combination of outlet manifold and inlet manifold, an array of cooling channels (e.g., in a thermally conductive plate) may be disposed between the adjacent manifolds (i.e., sandwiched between the outlet and inlet end plates in a stack) to carry away heat by flowing a fluid therethrough. Alternatively or additionally, thermal management techniques similar to those applied for cooling of ion exchange membranes in hydrogen fuel cells may be applied to regulate a temperature of the disclosed electrochemical modules.
Of course, although three parallel stages 100d-100f are illustrated in
As noted above, embodiments of the disclosed electrochemical modules can be employed in a vapor compression system employing the fluid as a working fluid (i.e., refrigerant), for example, as illustrated in
In system 500, the compressor 502 receives saturated CO2 vapor at 520 and compresses it to generate a higher-pressure CO2 vapor at 504. The CO2 vapor at 504 may be superheated vapor. As noted above, heat may be removed from compressor 502 (i.e., from the discharged CO2) such that the temperature of discharged CO2 is controlled for optimal performance of the vapor compression system 500 (e.g., to have a temperature at or slightly above that of the cooling heat exchanger 506). Heat 508 is transferred from CO2 vapor 504 via heat exchanger 506 to condense the CO2. After condenser 506, the CO2 at 510 may be saturated liquid. The expander 512 may receive the saturated CO2 liquid 510 and further reduce a pressure thereof to generate a lower pressure CO2 at 514, which may be a liquid-vapor CO2 blend. Heat 516 is transferred to lower pressure CO2 514 via heat exchanger 518 to evaporate the CO2. The resulting saturated CO2 vapor 520 can be conveyed back to compressor 502, where the cycle can repeat.
When the operating high-side temperature becomes higher than the critical temperature of CO2 and O2 mixture, the heat 508 rejection process becomes a supercritical gas cooling process. The entire cycle of system 500 therefore becomes a trans-critical cycle, and there is no two-phase condensation for heat 508 rejection nor evaporation for heat 516 absorption. Thus, heat exchanger 506 operates as a gas cooler rather than condenser while heat exchanger 518 operates as a gas heater rather than evaporator.
The electrochemical module may be employed as compressor 502 and/or expander 512 in system 500. For example,
Alternatively or additionally, the expander 512 of
The circulation of carrier gas in the vapor compression system may impact efficiency of the system, for example, by undermining heat exchanger performance. Thus, in embodiments, the transport of the carrier gas through the system may be limited by one more capture components. For example,
It is also possible to dispose the phase separator 561 at locations within the flow path of the vapor compression cycle different from that illustrated in
Alternatively or additionally, the carrier gas can be prevented from circulating in the vapor compression system by constructing each electrochemical device with carrier-gas-absorbing electrodes. The electrochemical devices can switch between operation as either a compressor or power-harvesting evaporator, depending on its mode of operation. For example,
The electrodes of the MEA in each electrochemical module 602, 612 can be formed, or having a coating, of LaMnO3 perovskite so as to store the O2 carrier gas therein and prevent O2 from circulating in the cycle outside of the respective MEA. Each electrochemical module 602, 612 can have a respective power module 604, 614, which is switchable between a power supply mode and a power storage mode, and a respective thermal regulation unit 606, 616 for removing heat during respective compression and/or expansion processes. A power line 618 can electrically connect the power modules 604, 614 together so as to share electrical power therebetween.
In a first mode 600a of operation illustrated in
The compression 804 of fluid by compressor 602a may be in a similar manner as described above with respect to
The compressed fluid is conveyed to heat exchanger 506, where heat is transferred from the fluid to cool (and in some configurations condense) the working fluid at 806. The cooled working fluid is conveyed to expander 612a. During the first mode 600a, the expansion 808 of working fluid by expander 612a may in a similar manner as described above with respect to
At the beginning of the first mode 600a, the cathode 624a has substantially all of the hydrogen in MEA 620 (i.e., is fully charged with O2), while the anode 626b has substantially none of the O2 (i.e., is fully discharged). Similarly, at the beginning of the first mode 600a, the anode 636a has substantially all of the O2 in MEA 630, while the cathode 634a has substantially none of the O2. The processes of the first mode 600a can continue until the inlet electrodes (i.e., cathode 624a of compressor 602a and anode 636a of expander 612a) are fully discharged, i.e., all of the O2 therein has been transferred through their respective AEM 622, 632 to charge the corresponding outlet electrodes (i.e., anode 626a of compressor 602a and cathode 634a of expander 612a). Thus, at 812, the process 800 can determine if regeneration of electrodes is required.
Once the inlet electrodes 624a, 636a have been fully discharged (i.e., depleted of O2), system 600 can switch to a second mode at 814. In the second mode 600b of operation, illustrated in
Thus, the compression 818 of working fluid by compressor 612b may be in a manner similar to that described above with respect to
Although 804-810 of the first mode are illustrated separately and 818, 806, 820, and 810 of the second mode are illustrated separately in
Although
For example,
In a first mode 650a, the first electrochemical device 602a operates as the compressor while the second electrochemical device 602b operates as the expander. Valve 652 is at a first orientation that routes discharge from port 658 of the first electrochemical device 602a to the inlet of cooling heat exchanger 506, and that routes discharge from the cooling heat exchanger 506 to port 662 of the second electrochemical device 602b. Valve 654 is at a first orientation that routes discharge from port 660 of the second electrochemical device 602b to the inlet of heating heat exchanger 518, and that routes discharge from the heating heat exchanger 518 to port 656 of the first electrochemical device 602a. In effect, the first mode 650a may operate similar to the first mode 600a of
Once the inlet electrodes have been exhausted (or when regeneration of electrodes is otherwise desired), the system can switch to the second mode 650b, as illustrated in
As compared to the first mode 650a, the direction of working fluid flow through the electrochemical devices 602a, 602b in the second mode 650b has been reversed. Moreover, the functions of the electrochemical devices 602a, 602b have been switched. Thus, the first electrochemical device 602a serves as compressor in the first mode 650a and as expander in the second mode 650b, and vice versa for the second electrochemical device 602b. However, the direction of working fluid flow through the cooling heat exchanger 506 (e.g., condenser) and heating heat exchanger 518 (e.g., evaporator) remains the same regardless of operation mode 650a, 650b.
Other configurations for regeneration of O2 storage electrodes in electrochemical devices are also possible according to one or more contemplated embodiments. For example,
In a first mode 670a, valves 672, 674 are in a respective first orientation. Thus, valve 672 routes working fluid discharged from port 676 of compressor 532 to the inlet of cooling heat exchanger 506, and routes working fluid discharged from heating heat exchanger 518 to port 678 of compressor 532. Valve 674 routes working fluid discharged from port 682 of expander 552 to the inlet of heating heat exchanger 518, and routes working fluid discharged from cooling heat exchanger 506 to port 680 of expander 552. In effect, the first mode 670a may operate similar to the first mode 600a of
Once the inlet electrodes have been exhausted (or when regeneration of electrodes is otherwise desired), the system can switch to the second mode 670b, as illustrated in
In another example of a system for electrode regeneration, an electrochemical device may have a pair of electrochemical modules that operate in an alternating manner to provide a particular thermodynamic process (e.g., electrochemical device acting as compressor). When the cathode of a first of the electrochemical modules becomes depleted, the system may switch the working fluid input to the second electrochemical module. A polarity of the electric field applied to the first electrochemical module can then be switched to allow regeneration of the input electrode while the second electrochemical module actively performs compression of the working fluid. The system may switch back and forth, redirecting working fluid input between the pair of electrochemical modules, such that one is always performing compression while the other is idle/recharging.
Embodiments of the disclosed electrochemical module are not limited to use in a vapor compression cycle. Rather, the electrochemical module can find use in a wide variety of applications where transport of a fluid through an anion exchange membrane using O2 as carrier gas is possible and desirable. For example, embodiments of the disclosed electrochemical device can be employed in a power generation system, such as an organic Rankine cycle (ORC) or a Brayton cycle, with CO2 as working fluid.
For example,
In ORC 1600, the pump 1602 (e.g., a conventional liquid pump or electrochemical device) receives liquid-phase working fluid at 1620 from condensing heat exchanger 1618 and pumps it to a higher pressure at 1604. Heat 1608 is transferred to the pumped working fluid 1604 via heat exchanger 1606 to generate vapor-phase working fluid at 1610. After evaporating heat exchanger 06, the vapor-phase working fluid 1610 is provided to an expansion device 1612 (e.g., a turbine or electrochemical device), which generates power 1626 by expanding the working fluid (a portion of which may be used a power 1624 for pump 1602). Heat 1616 is transferred from the resulting low pressure working fluid 1614 using condensing heat exchanger 1618. The resulting liquid-phase working fluid at 1620 can then be conveyed to pump 1602, where the cycle repeats. Heat 1608 can thus be used to generate a net power output 1626.
The electrochemical device may be employed as pump 1602 and/or expander 1612 in ORC 1600. For example,
In other configurations of Brayton cycle 1700, the output 1720 from turbine 1714 can be exhausted to the environment rather than recirculated at 1704 to pump 1702 (i.e., an open Brayton cycle rather than the illustrated closed Brayton cycle). In such configurations, input 1704 may be taken from ambient air, and at least the CO2 in the ambient air input is compressed by pump 1702.
The electrochemical device may be employed as pump 1702 and/or expander 1714 in Brayton cycle 1700. For example,
Alternatively or additionally, the pump 1702 of
Although the above description focused on electrochemical processing of a working fluid in a heating/cooling cycle (e.g., vapor compression cycle) or a power generation cycle (e.g., ORC or Brayton cycle), embodiments of the disclosed electrochemical module are not limited to such uses. Rather, the electrochemical module can be applied to transport of a fluid that is not otherwise considered a working fluid.
For example,
The flue gas 914 may include CO2 at a relatively low pressure (e.g., P1C=˜0.1-1 atm) and is incident on a cathode of the AEM of the electrochemical module 916. The catalyst of the cathode facilitates a reaction between the CO2 and O2 to form an anion at 1006. At 1008, a DC voltage is applied between the cathode and anode of the AEM of the electrochemical module 916, thereby transporting the anion through the AEM at 1010. The catalyst of the anode facilitates the reverse reaction to dissociate the anion back into CO2 and O2 at 1012. The electrochemical module 916 thus transports the CO2 across its AEM to isolate the CO2 920 from the inlet flue gas 914. The resulting CO2 920 may be at a relatively higher pressure (e.g., P2C=˜1-100 atm, such as 20 atm).
An outlet conduit 918 can direct the relatively higher-pressure CO2 stream 920 for further processing or use. For example, it may desirable to store the CO2 to prevent it from entering the atmosphere or for other purposes. Thus, in some embodiments, process 1000 proceeds to 1014, where outlet conduit 918 directs the CO2 stream 920 to a storage 922.
For example, storage 922 can include a potassium carbonate (K2CO3) solution, which can absorb the CO2 when combined at high pressure. In particular, the absorption process can be given by:
In general, the flue gas may have a sufficiently high temperature that the CO2 stream 920 does not require separate heating for combination with the K2CO3 solution. However, in some embodiments, 1014 can include heating the CO2 stream 920 to a sufficiently high temperature (e.g., ˜100° C.) for the above noted reaction with K2CO3.
Other options for storage 922 are also possible according to one or more contemplated embodiments. For example, storage 922 can include liquefying the captured CO2. The liquefied CO2 can then be injected into the ground, submerged in body of water (e.g., ocean), or sequestered in any other receptacle. In another example, storage 922 can be a receptacle such as a gas tank or cylinder, for example, for use of liquid CO2 in commercial or research purposes.
In some embodiments, the stored CO2 can be further processed to produce fuel, such as ethylene (C2H4) and/or methane (CH4). If it is determined that fuel is desirable at 1018, the process 1000 can proceed to 1020 for fuel production. For example, the fuel production process 1020 can employ the conversion system 960 illustrated in
Voltage applied by voltage source 964 to the electrodes 966, 968 causes an electrochemical reduction reaction to take place which generates a fuel stream from the KHCO3 solution. In particular, the reduction reaction can be given by:
The resulting fuel stream can be conveyed from reaction chamber 962 via an outlet conduit 920 for use or further processing. Returning to
Although 1002-1022 are illustrated separately in
Although the description of
Although the above description has focused on the transport of CO2, embodiments of the disclosed subject matter are not limited thereto. Rather, the electrochemical module can be applied to other fluids. Indeed, any fluid capable of a catalyst-driven reaction with O2 gas to form an anion can be transported using the disclosed electrochemical devices. For example, in some embodiments, the electrochemical device can be sued to capture water vapor from air (i.e., dehumidifier).
Air 1106 having a first humidity level can be directed to system 1100 via an inlet conduit 1104. In some embodiments, it may be desirable to increase efficiency of water vapor transfer by employing an electrohydrodynamic (EHD) module 1102 to direct water vapor in the air toward the AEM. For example, EHD module 1102 can include a coronator electrode, to which a high voltage is applied, and an electrode (e.g., mesh electrode), which is separate from but adjacent to the cathode of the AEM and which is held at ground.
In some embodiments, the EHD module 1102 may be integrated with the electrochemical module 1114, for example, as part of the inlet flow path to or inlet manifold of the electrochemical module 1114. For example,
Of course, other geometries other than those specifically illustrated in
Returning to
The electrochemical module 1114 thus transports the H2O across its AEM to isolate the H2O 1118 (which may now be at a relatively higher pressure) from the inlet air 1106. At 1514, the resulting dehydrated air 1110 can be conveyed from system 1100 by outlet conduit 1108, for example, to a conditioned space. Meanwhile, at 1516, an outlet conduit 1116 can direct the relatively higher-pressure H2O stream 1118 for further processing or use. For example, it may desirable to condense the water vapor to produce drinking or reclaimed water. Alternatively or additionally, the collected water vapor 1118 can be exhausted to atmosphere, stored for later, or condensed and disposed of. The process 1500 can then proceed to 1518, where it is determined if the process 1500 should be repeated, for example, as part of an ongoing dehumidification cycle, or any other cycle, in which case the process 1500 returns to 1502.
Although 1502-1518 are illustrated separately in
The electrochemical dehydration units (with or without integrated electrohydrodynamic unit) described above can be combined with a conventional heating/cooling/refrigeration (HCR) system (e.g., a vapor compression system) to improve cooling performance of the system. The combined electrochemical dehydration unit and HCR system may operate as a separate sensible and latent cooling (SSLC) system. The HCR system is thus configured to handle the sensible cooling while the electrochemical dehydration unit is configured to handle latent cooling (i.e., dehumidification). In the HCR system, the evaporator can be operated at a temperature higher than the dew point of the return air so that it handles the sensible load only. This results in a reduced temperature lift for the HCR system and a lower compressor power input, thereby improving the coefficient of performance (COP).
For example,
Thus, the HCR system 1406 can cool a first portion of return air by rejecting heat therein to working fluid flowing through evaporator 1412. Simultaneously, the electrochemical dehydration unit 1430 removes water vapor 1432 from the remaining portion 1426 of return air and any added outdoor air 1428, thereby providing latent cooling. The resulting dehumidified air 1434 can be combined with the cooled air 1436 from the HCR system 1406. A fan 1438 can direct the combined air 1440 to the space 1402 to provide thermal conditioning thereof.
Of course one of ordinary skill in the art will readily appreciate that the layout of
Although particular systems or cycles, in which the disclosed electrochemical device can be used to provide transport, pumping, compression, expansion, or power harvesting have been described, embodiments of the disclosed subject matter are not limited thereto. Indeed, one of ordinary skill in the applicable arts will readily appreciate that the disclosed electrochemical devices can be provide transport, pumping, compression, expansion, or power harvesting in other systems employing beyond those specifically discussed herein.
Moreover, aspects of the above described systems or cycles can be applied in isolation from other aspects thereof. For example, the electrochemical device may be used as a pump of fluid, whether or not part of a heating/cooling or power generation system. For example, the electrochemical device could be used to regenerate stale air (which may have a relatively high CO2 content) by transporting CO2 and/or humidity from input air across the AEM using O2 as carrier gas.
In addition, although particular configurations have been separately discussed above, the features of one particular configuration may apply to other configurations as well. For example, although
Moreover, although examples involving the separate electrochemical transport of CO2 and H2O have been discussed above, embodiments of the disclosed subject matter are not limited thereto. For example, in some embodiments, both CO2 and H2O (along with O2 carrier gas) may be simultaneously transported through AEM. In other embodiments, the material of the AEM and/or the catalyst of the electrodes can be chosen to preferentially select one of CO2 and H2O for transport through the AEM. For example, CO2 may be selected over H2O for transport by using a solid oxide membrane and operating at a relatively high temperature to form CO3−. In addition, the compounds that can be transported through the AEM are not limited CO2 and H2O. Rather any compound capable combining with O2 carrier gas or OH to form an anion can be transported by the disclosed electrochemical devices.
Although the description above has used the terms “fluid” and “working fluid,” it will be readily apparent to one of ordinary skill in the applicable arts that such terminology includes the vapor and supercritical phases as well as the liquid phase. Indeed, in some embodiments, the electrochemical device may receive a two-phase input (e.g., liquid-phase and vapor-phase CO2) and transport the input fluid across the AEM. Depending on temperature and pressure, the transported fluid may remain multi-phase or may become a single phase. In other embodiments, the electrochemical device may receive a liquid-phase only input, and thus may operate as a pump to transport the liquid-phase across the AEM. In still other embodiments, the fluid (e.g., CO2) input to the electrochemical device may be a supercritical fluid, which may be compressed and cooled during the compression process by the electrochemical device.
Moreover, although exemplary chemistries and materials have been discussed above, one of ordinary skill in the art will understand that the teachings of the present disclosure can be extended to other materials and chemistries. Thus, embodiments of the disclosed subject matter are not limited to the specific chemistries and materials discussed herein.
It will be appreciated that the aspects of the disclosed subject matter can be implemented, fully or partially, in hardware, hardware programmed by software, software instruction stored on a computer readable medium (e.g., a non-transitory computer readable medium), or any combination of the above.
For example, components of the disclosed subject matter, including components such as a controller, process, or any other feature, can include, but are not limited to, a personal computer or workstation or other such computing system that includes a processor, microprocessor, microcontroller device, or is comprised of control logic including integrated circuits such as, for example, an application specific integrated circuit (ASIC).
Features discussed herein can be performed on a single or distributed processor (single and/or multi-core), by components distributed across multiple computers or systems, or by components co-located in a single processor or system. For example, aspects of the disclosed subject matter can be implemented via a programmed general purpose computer, an integrated circuit device, (e.g., ASIC), a digital signal processor (DSP), an electronic device programmed with microcode (e.g., a microprocessor or microcontroller), a hard-wired electronic or logic circuit, a programmable logic circuit (e.g., programmable logic device (PLD), programmable logic array (PLA), field-programmable gate array (FPGA), programmable array logic (PAL)), software stored on a computer-readable medium or signal, an optical computing device, a networked system of electronic and/or optical devices, a special purpose computing device, a semiconductor chip, a software module or object stored on a computer-readable medium or signal.
When implemented in software, functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The steps of a method or algorithm disclosed herein may be embodied in a processor-executable software module, which may reside on a computer-readable medium. Instructions can be compiled from source code instructions provided in accordance with a programming language. The sequence of programmed instructions and data associated therewith can be stored in a computer-readable medium (e.g., a non-transitory computer readable medium), such as a computer memory or storage device, which can be any suitable memory apparatus, such as, but not limited to read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random-access memory (RAM), flash memory, disk drive, etc.
As used herein, computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. Thus, a storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code in the form of instructions or data structures and that may be accessed by a computer.
Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a transmission medium (e.g., coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave), then the transmission medium is included in the definition of computer-readable medium. Moreover, the operations of a method or algorithm may reside as one of (or any combination of) or a set of codes and/or instructions on a machine readable medium and/or computer-readable medium, which may be incorporated into a computer program product.
One of ordinary skill in the art will readily appreciate that the above description is not exhaustive, and that aspects of the disclosed subject matter may be implemented other than as specifically disclosed above. Indeed, embodiments of the disclosed subject matter can be implemented in hardware and/or software using any known or later developed systems, structures, devices, and/or software by those of ordinary skill in the applicable art from the functional description provided herein.
In this application, unless specifically stated otherwise, the use of the singular includes the plural, and the separate use of “or” and “and” includes the other, i.e., “and/or.” Furthermore, use of the terms “including” or “having,” as well as other forms such as “includes,” “included,” “has,” or “had,” are intended to have the same effect as “comprising” and thus should not be understood as limiting.
Any range described herein will be understood to include the endpoints and all values between the endpoints. Whenever “substantially,” “approximately,” “essentially,” “near,” or similar language is used in combination with a specific value, variations up to and including 10% of that value are intended, unless explicitly stated otherwise.
The terms “system,” “device,” and “module” have been used interchangeably herein, and the use of one term in the description of an embodiment does not preclude the application of the other terms to that embodiment or any other embodiment.
It is thus apparent that there is provided, in accordance with the present disclosure, systems, devices, and methods employing electrochemical processing with oxygen as carrier gas. Many alternatives, modifications, and variations are enabled by the present disclosure. While specific examples have been shown and described in detail to illustrate the application of the principles of the present invention, it will be understood that the invention may be embodied otherwise without departing from such principles. For example, disclosed features may be combined, rearranged, omitted, etc. to produce additional embodiments, while certain disclosed features may sometimes be used to advantage without a corresponding use of other features. Accordingly, Applicant intends to embrace all such alternative, modifications, equivalents, and variations that are within the spirit and scope of the present invention.
The present application claims the benefit of U.S. Provisional Application No. 62/590,922, filed Nov. 27, 2017, which is hereby incorporated by reference herein in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5041195 | Taylor | Aug 1991 | A |
| 5645700 | White | Jul 1997 | A |
| 6387230 | Murphy et al. | May 2002 | B1 |
| 7846604 | Highgate et al. | Dec 2010 | B2 |
| 8246723 | Wright et al. | Aug 2012 | B2 |
| 8584479 | Kuwabara et al. | Nov 2013 | B2 |
| 8627671 | Bahar | Jan 2014 | B2 |
| 8640492 | Bahar | Feb 2014 | B2 |
| 8769972 | Bahar | Jul 2014 | B2 |
| 9005411 | Bahar et al. | Apr 2015 | B2 |
| 9151283 | Bahar et al. | Oct 2015 | B2 |
| 9457324 | Bahar et al. | Oct 2016 | B2 |
| 9599364 | Bahar et al. | Mar 2017 | B2 |
| 9738981 | Naugler et al. | Aug 2017 | B2 |
| 10087532 | Bahar et al. | Oct 2018 | B2 |
| 10890344 | Bahar et al. | Jan 2021 | B2 |
| 11131029 | Wang et al. | Sep 2021 | B2 |
| 20020166763 | Tsai | Nov 2002 | A1 |
| 20040211679 | Wong et al. | Oct 2004 | A1 |
| 20090293526 | Ichinomiya | Dec 2009 | A1 |
| 20110133308 | Chan et al. | Jun 2011 | A1 |
| 20110207028 | Fukuta | Aug 2011 | A1 |
| 20150241091 | Bahar | Aug 2015 | A1 |
| 20160341449 | Bahar | Nov 2016 | A1 |
| 20170362720 | Bahar et al. | Dec 2017 | A1 |
| 20180058729 | Bahar | Mar 2018 | A1 |
| 20190161870 | Wang et al. | May 2019 | A1 |
| Number | Date | Country |
|---|---|---|
| WO-2013050146 | Apr 2013 | WO |
| WO 2017091785 | Jun 2017 | WO |
| WO-2018147253 | Aug 2018 | WO |
| WO 2018161711 | Sep 2018 | WO |
| Entry |
|---|
| English translation of Taku et al, JP 2010/ (Year: 2010). |
| Adams et al., “A Carbon Dioxide Tolerant Aqueous-Electrolyte-Free Anion-Exchange Membrane Alkaline Fuel Cell,” ChemSusChem, Dec. 2007, 1: pp. 79-81. (3 pages). |
| Bedbak et al., “Performance analysis of a compressor driven metal hydride cooling system,” International Journal of Hydrogen Energy, Dec. 2004, 30: pp. 1127-1137. (11 pages). |
| Bullecks et al., “Development of a cylindrical PEM fuel cell,” International Journal of Hydrogen Energy, Nov. 2010, 36: pp. 713-719. (7 pages). |
| Bussayajarn et al., “Planar air breathing PEMFC with self-humidifying MEA and open cathode geometry design for portable applications,” SIMTech technical reports, 2010, 11(2): pp. 66-69. (4 pages). |
| Chen et al., “Hydroxide Solvation and Transport in Anion Exchange Membranes,” Journal of the American Chemical Society, Dec. 2015, 138: pp. 991-1000. (10 pages). |
| Chu et al., “Performance of polymer electrolyte membrane fuel cell (PEMFC) stacks. Part I. Evaluation and simulation of an air-breathing PEMFC stack,” Journal of Power Sources, 1999, 83: pp. 128-133. (6 pages). |
| Dais Analytic Corporation, “Membrane dehumidification enabling alternative cooling strategies in humid environments,” Presentation at ARPA-E Summit [online], Feb. 2013 [retrieved on Nov. 14, 2022]. Retrieved from the Internet: <URL: http://www.arpae-summit.com/paperclip/exhibitor_docs/13AE/Dais_Analytic_Corporation_104.pdf>. (11 pages). |
| Dekel, Dario R. “Review of cell performance in anion exchange membrane fuel cells,” Journal of Power Sources, Aug. 2017, 375: pp. 158-169. (12 pages). |
| Fabian et al., “The role of ambient conditions on the performance of a planar, air-breathing hydrogen PEM fuel cell,” Journal of Power Sources, May 2006, 161: pp. 168-182. (15 pages). |
| Faghri et al., “Challenges and opportunities of thermal management issues related to fuel cell technology and modeling,” International Journal of Heat and Mass Transfer, 2005, 48: pp. 3891-3920. (30 pages). |
| Ganley, Jason C., “An intermediate-temperature direct ammonia fuel cell with a molten alkaline hydroxide electrolyte,” Journal of Power Sources, Dec. 2007, 178: pp. 44-47. (4 pages). |
| Gardner et al., “Electrochemical separation of hydrogen from reformate using PEM fuel cell technology,” Journal of Power Sources, Jun. 2007, 171: pp. 835-841. (7 pages). |
| Gerlach, David W., “Experimental Verification of Electroosmotic Dehumidification with Nafion and Plaster-Silica Gel Membranes,” International Refrigeration and Air Conditioning Conference, Jul. 2008, Paper No. 862 (2436). (9 pages). |
| Grigoriev et al., “Description and characterization of an electrochemical hydrogen compressor/concentrator based on solid polymer electrolyte technology,” International Journal of Hydrogen Energy, Aug. 2010, 36: pp. 4148-4155. (8 pages). |
| Halseid et al., “Effect of ammonia on the performance of polymer electrolyte membrane fuel cells,” Journal of Power Sources, Dec. 2005, 154: pp. 343-350. (8 pages). |
| Hopkins et al., “Hydrogen compression characteristics of a dual stage thermal compressor system utilizing LaNi5 and Ca0.6Mm0.4Ni5 as the working metal hydrides,” International Journal of Hydrogen Energy, Apr. 2010, 35: pp. 5693-5702. (10 pages). |
| Iwahara et al., “Electrochemical dehumidification using proton conducting ceramics,” Solid State Ionics, 2000, 136-137: pp. 133-138. (6 pages). |
| Jeong et al., “Effects of cathode open area and relative humidity on the performance of air-breathing polymer electrolyte membrane fuel cells,” Journal of Power Sources, Nov. 2005, 158: pp. 348-353. (6 pages). |
| Joo et al., “Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation,” Nano Letters, Jun. 2010, 10: pp. 2709-2713. (5 pages). |
| Jung et al., “An experimental approach to investigate the transport of ammonia as a fuel contaminant in proton exchange membrane fuel cells,” Journal of Power Sources, Nov. 2014, 275: pp. 14-21. (8 pages). |
| Kamkari et al., “Investigation of Electrohydrodynamically-Enhanced Convective Heat and Mass Transfer from Water Surface,” Heat Transfer Engineering, 2010, 31(2): pp. 138-146. (9 pages). |
| Kim et al., “Air-breathing miniature planar stack using the flexible printed circuit board as a current collector,” International Journal of Hydrogen Energy, Nov. 2008, 34: pp. 459-466. (8 pages). |
| Lai et al., “EHD-enhanced drying with multiple needle electrode,” Journal of Electrostatics, Dec. 2004, 63: pp. 223-237. (15 pages). |
| Li et al., “The performance of PEM fuel cells fed with oxygen through the free-convection mode,” Journal of Power Sources, 2003, 114: pp. 63-69. (7 pages). |
| Luo et al., “An Acrylate-Polymer-Based Electrolyte Membrane for Alkaline Fuel Cell Applications,” ChemSumChem, 2011, 4: pp. 1557-1560. (4 pages). |
| Matian et al., “Model based design and test of cooling plates for an air-cooled polymer electrolyte fuel cell stack,” International Journal of Hydrogen Energy, Mar. 2011, 36: pp. 6051-6066. (16 pages). |
| Mefford et al., “Anion charge storage through oxygen intercalation in LaMnO3 perovskite pseudocapacitor electrodes,” Nature Materials, Jul. 2014, 13: pp. 726-732. (7 pages). |
| Mehta et al., “Review and analysis of PEM fuel cell design and manufacturing,” Journal of Power Sources, 2003, 114: pp. 32-53. (22 pages). |
| Misran et al., “Water transport characteristics of a PEM fuel cell at various operating pressures and temperatures,” International Journal of Hydrogen Energy, Jan. 2013, 38: pp. 9401-9408. (8 pages). |
| Moton et al., “Advances in Electrochemical Compression of Hydrogen,” Proceedings of the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology, Jun. 30-Jul. 2, 2014. (10 pages). |
| Muthukumar et al., “Metal hydride based heating and cooling systems: A review,” International Journal of Hydrogen Energy, Feb. 2010, 35: pp. 3817-3831. (15 pages). |
| Odabaee et al., “Metal foam heat exchangers for thermal management of fuel cell systems—An experimental study,” Experimental Thermal and Fluid Science, Aug. 2013, 51: pp. 214-219. (6 pages). |
| Ohadi et al., “Heat transfer enhancement of laminar and turbulent pipe flow via corona discharge,” Int. J. Heat Mass Transfer, 1991, 34(4/5): pp. 1175-1187. (13 pages). |
| Onda et al., “Separation and compression characteristics of hydrogen by use of proton exchange membrane,” Journal of Power Sources, Nov. 2006, 164: pp. 1-8. (8 pages). |
| Pandey et al., “Insight on pure vs air exposed hydroxide ion conductivity in an anion exchange membrane for fuel cell applications,” ECS Transactions, 2014, 64(3): pp. 1195-1200. (6 pages). |
| Pennline et al., “Separation of CO2 from flue gas using electrochemical cells,” Fuel, Dec. 2009, 89: pp. 1307-1314. (8 pages). |
| Qi et al., “Performance investigation on polymeric electrolyte membrane-based electrochemical air dehumidification system,” Applied Energy, Sep. 2017, 208: pp. 1174-1183. (10 pages). |
| Rigdon et al., “Reaction Dependent Transport of Carbonate and Bicarbonate through Anion Exchange Membranes in Electrolysis and Fuel Cell Operations,” ECS Transactions, 2015, 69(33): pp. 1-9. (9 pages). |
| Sakuma et al., “Estimation of dehumidifying performance of solid polymer electrolytic dehumidifier for practical application,” J Appl Electrochem, Sep. 2010, 40: pp. 2153-2160. (8 pages). |
| Sakuma et al., “Water transfer simulation of an electrolytic dehumidifier,” J Appl Electrochem, Nov. 2008, 39: pp. 815-825. (11 pages). |
| Shafiee et al., “Different reactor and heat exchanger configurations for metal hydride hydrogen storage systems—A review,” International Journal of Hydrogen Energy, May 2016, 41: pp. 9462-9470. (9 pages). |
| Shaughnessy et al., “Electrohydrodynamic Pressure of the Point-to-Plane Corona Discharge,” Aerosol Science and Technology, 1991, 14: pp. 193-200. (8 pages). |
| Soto et al., “Effect of Transient Ammonia Concentrations on PEMFC Performance,” Electrochemical and Solid-State Letters, Apr. 2003, 6(7): pp. A133-A135. (3 pages). |
| Strobel et al., “The compression of hydrogen in an electrochemical cell based on a PE fuel cell design,” Journal of Power Sources, 2002, 105: pp. 208-215. (8 pages). |
| Tao et al., “Electrochemical ammonia compression,” Chem. Commun., 2017, 53: pp. 5637-5640. (4 pages). |
| Tao et al., “Electrochemical compressor driven metal hydride heat pump,” International Journal of Refrigeration, Aug. 2015, 60: pp. 278-288. (11 pages). |
| Tao et al., “Performance Investigation on Electrochemical Compressor with Ammonia,” 23rd International Compressor Engineering Conference at Purdue, Jul. 2016, Paper No. 2469(1380). (6 pages). |
| Unlu et al., “Anion Exchange Membrane Fuel Cells: Experimental Comparison of Hydroxide and Carbonate Conductive Ions,” Electrochemical and Solid-State Letters, Jan. 2009, 12(3): pp. B27-B30. (4 pages). |
| Uribe et al., “Effect of Ammonia as Potential Fuel Impurity on Proton Exchange Membrane Fuel Cell Performance,” Journal of the Electrochemical Society, Jan. 2002, 149(3): pp. A293-A296. (4 pages). |
| Varcoe et al., “Anion-exchange membranes in electrochemical energy systems,” Energy & Environmental Science, 2014, 7: pp. 3135-3191. (57 pages). |
| Vega et al., “Carbonate Selective Ca2Ru2O7-y Pyrochlore Enabling Room Temperature Carbonate Fuel Cells, I. Synthesis and Physical Characterization” Journal of the Electrochemical Society, Dec. 2011, 159(1): pp. B12-B17. (6 pages). |
| Vega et al. “Carbonate Selective Ca2Ru2O7-y Pyrochlore Enabling Room Temperature Carbonate Fuel Cells, II. Verification of Carbonate Cycle and Electrochemical Performance,” Journal of the Electrochemical Society, 2012, 159(1): pp. B18-B23. (6 pages). |
| Wang et al., “Investigation of potential benefits of compressor cooling,” Applied Thermal Engineering, Nov. 2007, 28: pp. 1791-1797. (7 pages). |
| Weng et al., “Electrochemical CO2 Reduction to Hydrocarbons on a Heterogeneous Molecular Cu Catalyst in Aqueous Solution,” Journal of the American Chemical Society, Jun. 2016, 138: pp. 8076-8079. (4 pages). |
| Zhang et al., “A critical review of cooling techniques in proton exchange membrane fuel cell stacks,” International Journal of Hydrogen Energy, Nov. 2011, 37: pp. 2412-2429. (18 pages). |
| Zhou et al., “Anionic polysulfone ionomers and membranes containing fluorenyl groups for anionic fuel cells,” Journal of Power Sources, Jan. 2009, 190: pp. 285-292. (8 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20190165405 A1 | May 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62590922 | Nov 2017 | US |
