A system and filtration cartridge for purifying emissions from fuel cell systems.

Abstract

The present invention provides a system for purifying emissions from fuel cell systems, and a filtration cartridge for the emission purification system. [Solution] The fuel cell system 100 comprises at least one reservoir 20 having a filtration cartridge 40 having an adsorbent / absorbent material 42 configured to remove perfluoroalkyl and polyfluoroalkyl substances from the exhaust, and a discharge valve 50 connected to an outlet port 26 of at least one reservoir 20.

Description

Technical Field

[0001] Embodiments relate to a system for purifying emissions of a fuel cell system and a filter cartridge for a system for purifying emissions of a fuel cell system.

Background Art

[0002] Perfluorinated and polyfluorinated materials are often used at different positions in a proton exchange membrane (PEM) fuel cell system due to their high stability. For example, the stack membrane of a PEM fuel cell system is often made from perfluorosulfonic acid (PFSA) to provide good ionic conductivity, electrical resistance, and membrane thickness. However, under difficult operating conditions, the membrane degrades, leading to the emission of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the cathode drain water.

[0003] When PFAS enters the environment, for example through the emissions of a fuel cell, it cannot be further decomposed through natural processes, accumulates in soil and water, and thus in food and beverages, potentially leading to health problems. Therefore, regulations have been introduced to prevent PFAS emissions to the environment, and their use in many applications across the industry will be prohibited. These regulations may put fuel cells, and more broadly hydrogen technologies (such as electrolyzers and system components) at risk because PFAS-free alternatives with similar performance and cost may not be available on the market in time.

[0004] U.S. Patent No. 6,855,449 discloses a fuel cell body and a circulation path for circulating water passing through the fuel cell body. This fuel cell system has a fluoride absorber embedded in the water circulation path, and is characterized in that the fluoride absorber absorbs fluorine from the water circulating in the water circulation path.

[0005] International Publication No. 2006 / 038325 discloses a fuel cell water treatment apparatus in which water recovered from a fuel cell is treated by an electrodeionization unit, and the apparatus is improved to achieve good defluorination from the water flowing into the electrodeionization unit. Wastewater from the negative electrode chamber of the electrodeionization unit is supplied to an air cleaning chamber through a transfer pipe, where air cleaning is performed. The resulting water is decarboxylated in a decarbonation chamber and then pumped to flow sequentially through a defluorination chamber and a demetallation chamber before being supplied to the electrodeionization unit. [Overview of the project]

[0006] The objective of this embodiment is to provide an improved system for purifying emissions from a fuel cell system.

[0007] A further objective of the embodiment is to provide a filtration cartridge for an improved system for purifying emissions from a fuel cell system.

[0008] According to one aspect of this embodiment, the objective is achieved by a system for purifying emissions from a fuel cell system, comprising at least one reservoir having a filtration cartridge with an adsorbent / absorbent material configured to remove perfluoroalkyl and polyfluoroalkyl substances from the emissions, and a discharge valve connected to the outlet port of at least one reservoir.

[0009] According to a further embodiment of this invention, a further object is achieved by a filtration cartridge for a system, the filtration cartridge comprising a cartridge container filled with an adsorbent / absorbent material, the cartridge container having at least one inlet opening and at least one outlet opening. The adsorbent / absorbent material is located inside the cartridge container and between at least one inlet opening and at least one outlet opening.

[0010] Advantageous embodiments are derived from the dependent claims, specification, and drawings.

[0011] The proposed system includes a system for capturing perfluoroalkyl and polyfluoroalkyl substances (PFAS) from fuel cell emissions before they are released into the environment. This may be designed to be part of a fuel cell stack used in mobile applications such as fuel cell electric vehicles (FCEVs), stationary energy production, and other fuel cell systems.

[0012] According to this embodiment, the system may further comprise other reservoirs, each containing other filter cartridges having other adsorbents / absorbents configured to further remove perfluoroalkyl and polyfluoroalkyl substances from the waste. The discharge valve may be connected to the inlet port of the other reservoir, which may further comprise an outlet port for the purified waste. Advantageously, these filter cartridges may contain different adsorbents / absorbents, thereby allowing the filter cartridges in the other reservoirs to effectively separate specific compounds only after the concentration of other compounds competing with the free binding site has been significantly reduced by the filter cartridge in at least one reservoir.

[0013] According to this embodiment, the system may further include a water separator for separating water from the airflow, the water separator comprising an inlet port for the airflow, an outlet port for the airflow from which the water has been separated, and a water discharge port for the water separated from the airflow. At least one reservoir inlet port may be connected to the water discharge port of the water separator.

[0014] The system may be based on two existing components, namely a water separator and an ion exchanger. The water separator may be located, for example, directly at the discharge port of the fuel cell, or between the turbine outlet and the outlet of the hydrogen purge valve. The water separator can separate water from the fuel cell discharge. Depending on the rate of the removal process, a two-stage reservoir is envisioned. The water flowing out of the water separator is collected in a first reservoir containing one or any combination of adsorbents / absorbents, activated carbon, and ion exchange resins, specifically designed to remove PFAS from the water. A second reservoir may collect water from which PFAS has been at least partially removed in the first reservoir, and contains one or any combination of adsorbents / absorbents, activated carbon, and ion exchange resins, specifically designed to remove residual PFAS from the water. Sensors may be integrated to measure the reservoir's fill level.

[0015] Over time, the adsorbent / absorbent material becomes saturated with PFAS ions. Therefore, the adsorbent / absorbent material may be applied to a cartridge that can be easily replaced with a new one.

[0016] Therefore, the distinguishing features of this system are its ability to separate water from fuel cell emissions and to remove PFAS from this water.

[0017] Advantageously, a solution is provided to capture PFAS in wastewater from fuel cells before it is released into the environment, thereby enabling compliance with future regulatory requirements regarding PFAS released into the environment.

[0018] According to a preferred embodiment of the system, the filtration cartridge may be positioned inside at least one reservoir and the other reservoir, respectively, such that the inlet port of at least one reservoir and the inlet port of the other reservoir are separated by the filtration cartridge from the outlet port of at least one reservoir and the outlet port of the other reservoir, respectively. This forces the fluid flow from the inlet port to the outlet port of the reservoir to flow through the filtration cartridge.

[0019] According to a preferred embodiment of the system, at least one reservoir and other reservoirs may each comprise a housing in which a filtration cartridge is respectively placed. The filtration cartridge, filled with adsorbent / absorbent material, can be replaced when the adsorbent / absorbent material becomes saturated.

[0020] According to a preferred embodiment of the system, each filtration cartridge may comprise a cartridge container filled with an adsorbent / absorbent material, the cartridge container having at least one inlet opening and at least one outlet opening. The adsorbent / absorbent material may be placed inside the cartridge container and between at least one inlet opening and at least one outlet opening. This allows for easy handling of the adsorbent / absorbent material, activated carbon, ion exchange resin, and / or bead structure bed.

[0021] According to a preferred embodiment of the system, the housings of at least one reservoir and other reservoirs each have sealing fittings for housing the respective filtration cartridges, such that the fluid flow from the inlet opening to the outlet opening is forced to pass through each of the filtration cartridges. This ensures that the water from the water separator is purified by the adsorbent / absorbent material.

[0022] According to a preferred embodiment of the system, the discharge valve may be for controlling the contact time between the adsorbent / absorbent material and the discharge. This allows control over the adsorption process of PFAS on the adsorbent / absorbent material.

[0023] According to a preferred embodiment of the system, the adsorbent / absorbent material may be activated carbon, ion exchange resin, and a bead structure bed, or any combination thereof. Advantageously, the removal of PFAS from water is facilitated.

[0024] According to a preferred embodiment of the system, the filtration cartridge may be replaceable. The filtration cartridge filled with the adsorption / absorbent material can be replaced when the adsorption / absorbent material is saturated.

[0025] The proposed filtration cartridge can be used in a PFAS capture system from fuel cell emissions before being released into the environment.

[0026] The water flowing out from the water separator of the system may be recovered into a first reservoir equipped with a filtration cartridge containing any one or any combination of an adsorption / absorbent material, activated carbon, and an ion exchange resin, which is specially designed to remove PFAS from water. Also, the second reservoir may also be equipped with another filtration cartridge containing any one or any combination of an adsorption / absorbent material, activated carbon, and an ion exchange resin, which is specially designed to remove residual PFAS from water.

[0027] Over time, the adsorption / absorbent material will become saturated with PFAS ions. Therefore, the filtration cartridge is designed to be easily replaced with a new one. <0​​​​​​​​​​This embodiment can be best understood from the following detailed description of the embodiments together with the above and other objects and advantages, but is not limited to these embodiments.

Brief Description of the Drawings

[0031] [Figure 1] It is a diagram showing a system for purifying the exhaust of a fuel cell system according to this embodiment. [Figure 2] It is a diagram showing the water separator of the system of FIG. 1. [Figure 3] It is a diagram showing the layout of a fuel cell system provided with the system of FIG. 1.

Mode for Carrying Out the Invention

[0032] In the drawings, the same elements are denoted by the same reference numerals. The drawings are merely schematic representations and are not intended to depict specific parameters of the embodiments. Also, the drawings are intended to depict only typical embodiments and should not be considered as limiting the scope of the embodiments.

[0033] FIG. 1 shows a system 100 for purifying the exhaust of a fuel cell system 200 according to an embodiment.

[0034] As shown in FIG. 3, the system 100 is directly connected to the exhaust line of the fuel cell system 200 or is arranged along the exhaust line, near the outlet, and immediately before the drainage to the environment or the return to the fuel cell system 200.

[0035] System 100 comprises four main components arranged in a two-stage reservoir configuration. First, fuel cell emissions flowing out from the fuel cell stack pass through a water separator 10 configured to transfer water droplets from the fuel cell emissions to a water wall membrane, where these droplets can be discharged as liquid water. The liquid water then flows into a first reservoir 20 containing an adsorbent / absorbent material 42. A discharge valve 50 connected to this first reservoir 20 holds the water and ensures maximum contact time with the adsorbent / absorbent material 42 for effective filtration. If additional contact time is required, the water flows into a second reservoir 30 for a secondary filtration phase. The second reservoir 30 then discharges the purified emissions directly into the environment or back into the rest of the fuel cell stack.

[0036] As shown in Figure 1, the system 100 includes a water separator 10 for separating water from a first airflow having a first water content. The water separator 10 includes an inlet port 12 for the first airflow, an outlet port 14 for a second airflow having a second water content, and a water discharge port 16 for the water separated from the first airflow. The first water content is higher than the second water content.

[0037] The system 100 further comprises a first reservoir 20 and a second reservoir 30, each having a filtration cartridge 40 having an adsorption / absorbent material 42, and a discharge valve 50.

[0038] The inlet port 24 of the first reservoir 20 is connected to the water discharge port 16 of the water separator 10. The outlet port 26 of the first reservoir 20 is connected to the discharge valve 50, and the discharge valve 50 is connected to the inlet port 34 of the second reservoir 30.

[0039] The second reservoir 30 is equipped with an outlet port 36 for the purified waste.

[0040] The adsorbent / absorbent material 42 inside the filtration cartridge 40 is configured to remove at least perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water.

[0041] Figure 2 shows the function of the water separator 10 in the system 100 of Figure 1.

[0042] The first airflow, i.e., air containing high-concentration water droplets 13, flows into the water separator 10 through the inlet port 12. In the swirling flow generator stage 15, heavier water droplets 13 are pushed against the outer wall of the water separator 10 by centrifugal force, thus forming a water film 11 on the pipe wall. In the external diffuser 17, the water is separated in the water discharge region 18 and led to the water discharge port 16 of the water separator 10. The internal diffuser 19 separates a second airflow that is led to the outlet port 14. The second airflow contains only low-concentration water droplets 13.

[0043] The first and second reservoirs 20 and 30 are each equipped with housings 22 and 32, respectively, and the filtration cartridge 40 is located inside the housings 22 and 32.

[0044] The filtration cartridge 40 comprises a cartridge container 48 filled with an adsorbent / absorbent material 42. The cartridge container 48 has at least one inlet opening 44 and at least one outlet opening 46, and the adsorbent / absorbent material 42 is located inside the cartridge container 48 and between at least one inlet opening 44 and at least one outlet opening 46.

[0045] The adsorbent / absorbent material 42 may be one or any combination of activated carbon, ion exchange resin, and a bead structure bed for removing at least PFAS from water.

[0046] At least one inlet opening 44 and at least one outlet opening 46 are equipped with a sieve or fluid-permeable membrane to retain the adsorbent / absorbent material 42 inside the cartridge container 48, particularly when the adsorbent / absorbent material 42 is a bead-structured floor.

[0047] The filtration cartridge 40 is positioned inside the housings 22, 32 of the first and second reservoirs 20, 30 such that the inlet ports 24, 34 of the first and second reservoirs 20, 30 are separated from the outlet ports 26, 36 by the filtration cartridge 40. For this purpose, the housings 22, 32 of the first and second reservoirs 20, 30 each have sealing fittings 28, 38 for housing the filtration cartridge 40 such that the fluid flow from the inlet opening 44 to the outlet opening 46 is forced to pass through the filtration cartridge 40.

[0048] The filtration cartridges 40 are arranged to be replaceable so that they can be replaced when the adsorbent / absorbent material 42 is saturated with PFAS. These filtration cartridges 40 may contain different adsorbent / absorbent materials 42, so that the filtration cartridges 40 in the second reservoir 30 may effectively separate a particular compound only after the concentration of other compounds competing with the free binding site has been significantly reduced by the filtration cartridges 40 in the first reservoir 20.

[0049] The discharge valve 50 is configured to control the contact time between the adsorbent / absorbent material 42 and the water separated from the first airflow. Therefore, the discharge valve 50 can hold water in the first reservoir 20 in order to increase the reaction time of the water with the adsorbent / absorbent material 42.

[0050] Figure 3 shows the layout of the fuel cell system equipped with the system 100 of Figure 1.

[0051] The fuel cell system 200 receives air through the cathode air filter 60. The air is led to the compressor 62. The compressed air is cooled in the charge air cooler 64, humidified in the humidifier 66, and supplied to the fuel cell stack 68.

[0052] The emissions exit the fuel cell stack 68 and are supplied to system 100, i.e., a first system 100a for PFAS removal, at a first branch 52. The first branch 52 is a cathode discharge path interposed between the fuel cell stack 68 and the humidifier 66. System 100a may release the emissions, from which water has been separated, into the environment, or it may purify the PFAS in the emissions before releasing them into the environment, and / or it may send the purified emissions back to the fuel cell system 200, for example, the humidifier 66.

[0053] The emissions exit the fuel cell stack 68 and are supplied at a second branch 54 to system 100, i.e., a second system 100b for PFAS removal. The second branch 54 is another cathode emissions path from the fuel cell stack 68 to a point downstream of the humidifier 66 and before the compressor 62. System 100b may release the emissions separated by water into the environment, purify the PFAS from the emissions before releasing them into the environment, and / or send the purified emissions back to the fuel cell system 200, e.g., the compressor 62.

[0054] System 100 is further positioned as a third system 100c downstream of a mixer (not shown) that mixes the emissions from the compressor 62 with the purge gas from the anode loop. System 100c may release the emissions, separated by water, into the environment, purify the PFAS from the emissions before releasing them into the environment, and / or send the purified emissions back to the fuel cell system 200. [Explanation of Symbols]

[0055] 10 Water separator 11 Water film 12 Inlet port, first airflow 13 water drops 14. Outlet port, second airflow 15 Swirling flow generator 16 Water discharge ports 17 External diffuser 18 Water discharge area 19 Internal diffuser 20 First Reservoir 22 Housing 24 Entrance Ports 26 Exit Ports 28 Seal fitting section 30 Second Reservoir 32 Housing 34 Entrance Port 36 Exit Ports 38 Seal fitting section 40 filtration cartridges 42 Adsorbent / Absorbent Materials 44 Inflow opening 46 Outlet opening 48 cartridge containers 50 Discharge valve 52 The first branch 54 The second branch 60 Cathode Air Filter 62 Compressor 64 Charge Air Cooler 66 Humidifier 68 Fuel Cell Stack 100 Systems 100a System 1 100b Second System 100c Third System 200 Fuel Cell Systems

Claims

1. A system (100) for purifying emissions from a fuel cell system (200), A reservoir (20) comprising at least one filtration cartridge (40) having an adsorbent / absorbent material (42) configured to remove perfluoroalkyl and polyfluoroalkyl substances from the aforementioned waste, A system (100) comprising a discharge valve (50) connected to the outlet port (26) of at least one reservoir (20).

2. The reservoir (30) further comprises another filtration cartridge (40) having another adsorbent / absorbent material (42) configured to further remove perfluoroalkyl and polyfluoroalkyl substances from the discharge, The discharge valve (50) is connected to the inlet port (34) of the other reservoir (30), The system (100) according to claim 1, wherein the other reservoir (30) further comprises an outlet port (36) for purified waste.

3. The system (100) according to claim 2, wherein the filtration cartridge (40) is positioned inside the at least one reservoir (20) and the other reservoir (30) respectively, such that the inlet port (24) of the at least one reservoir (20) and the inlet port (34) of the other reservoir (30) are separated by the filtration cartridge (40) from the outlet port (26) of the at least one reservoir (20) and the outlet port (36) of the other reservoir (30).

4. The system (100) according to claim 2 or 3, wherein at least one reservoir (20) and the other reservoir (30) each comprises housings (22, 32) in which the filtration cartridge (40) is respectively disposed.

5. Each of the filtration cartridges (40) comprises a cartridge container (48) filled with the adsorbent / absorbent material (42), the cartridge container (48) having at least one inlet opening (44) and at least one outlet opening (46), The system (100) according to claim 4, wherein the adsorption / absorbent material (42) is disposed inside the cartridge container (48) and between the at least one inlet opening (44) and the at least one outlet opening (46).

6. The system (100) according to claim 5, wherein the housings (22, 32) of the at least one reservoir (20) and the other reservoir (30) each have sealing fittings (28, 38) for housing the filtration cartridges (40) respectively, such that a fluid flow from the at least one inlet opening (44) to the at least one outlet opening (46) is forced through each of the filtration cartridges (40).

7. The system (100) according to any one of claims 1 to 3, wherein the discharge valve (50) is for controlling the contact time between the adsorption / absorbent material (42) and the discharged material.

8. The system (100) according to any one of claims 1 to 3, wherein the adsorbent / absorbent material (42) is one or any combination of activated carbon, ion exchange resin, and bead structure bed.

9. The system (100) according to any one of claims 1 to 3, wherein the filtration cartridge (40) is replaceable.

10. The system further comprises a water separator (10) for separating water from the airflow, the water separator (10) comprising an inlet port (12) for the airflow, an outlet port (14) for the airflow from which the water has been separated, and a water discharge port (16) for the water separated from the airflow. The system (100) according to any one of claims 1 to 3, wherein the inlet port (24) of at least one reservoir (20) is connected to the water discharge port (16) of the water separator (10).

11. The system (100) is a first system (100a) interposed between the fuel cell stack (68) and the humidifier (66) of the fuel cell system (200), The system (100) according to any one of claims 1 to 3, wherein the emissions are from the fuel cell stack (68).

12. The system (100) is a second system (100b) interposed between the humidifier (66) and the compressor (62) of the fuel cell system (200), The system (100) according to any one of claims 1 to 3, wherein the emissions are from the fuel cell stack (68) and / or the humidifier (66).

13. The system (100) is a third system (100c) located downstream of the mixer of the fuel cell system (200), The system (100) according to any one of claims 1 to 3, wherein the discharge is from the mixer and is a mixture of discharge from the compressor (62) and purge gas from the anode loop.

14. A filtration cartridge (40) for a system (100) according to any one of claims 1 to 3, The filtration cartridge (40) comprises a cartridge container (48) filled with the adsorbent / absorbent material (42), and the cartridge container (48) has at least one inlet opening (44) and at least one outlet opening (46). The adsorbent / absorbent material (42) is disposed inside the cartridge container (48) and between the at least one inlet opening (44) and the at least one outlet opening (46) of the filtration cartridge (40).

15. Each of the at least one inlet opening (44) and the at least one outlet opening (46) is equipped with a sieve or a fluid-permeable membrane. The filtration cartridge (40) according to claim 14, wherein the adsorbent / absorbent material (42) is one or any combination of activated carbon, ion exchange resin, and a bead structure bed.

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