JP2005347231A - Water processing device for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water processing device for a fuel cell processing the water collected from the fuel cell by an electric deionization apparatus improved so as to sufficiently remove fluorine flown into the electric deionization apparatus. <P>SOLUTION: The air is purified by guiding the water drained from an anode chamber of the electric deionization apparatus 4 to a gas-cleaning chamber 20 through a transport tube 18. After being decarbonated at a decarbonating chamber 30, the air is made to flow through fluorine removing chambers 70, 72, 74, and metal removing chambers 80, 82 successively, and supplied to the electric deionization apparatus 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell water treatment device for treating water recovered from a fuel cell with an electrodeionization device, and more particularly to a fuel cell water treatment device suitable when the fuel cell is a polymer electrolyte fuel cell.

  In order to recover and treat water such as condensed water discharged from the fuel cell and use it as a water source for a fuel reformer (steam reformer), the recovered water can be treated with an electrodeionization device. It is described in JP-A-9-161833, JP-A-2001-232394, and the like.

  In the former Japanese Patent Laid-Open No. 9-161833, the fuel cell is a phosphoric acid fuel cell, and in the latter Japanese Patent Laid-Open No. 2001-232394, the fuel cell is a solid polymer fuel cell. .

  In this polymer electrolyte fuel cell, a fluorine-based cation exchange membrane is used as a solid electrolyte, and the fuel cell wastewater contains a small amount of fluorine ions. For this reason, in the type of water treatment device that treats phosphoric acid fuel cell waste water as in the above-mentioned JP-A-9-161833, fluorine is not removed, and the ion exchanger in the electrodeionization device is quickly removed by fluorine. May deteriorate.

The latter Japanese Patent Application Laid-Open No. 2001-232394 describes that condensed water of a polymer electrolyte fuel cell is subjected to decarboxylation treatment, reverse osmosis membrane treatment (RO treatment), and electrodeionization treatment.
JP-A-9-161833 JP 2001-232394 A

  I. In JP-A-2001-232394, as described in paragraph 0029, about 90% of the dissolved ion component is removed by the RO device provided in the previous stage of the electrodeionization device, but still some fluorine ions are in the RO. There is a risk of flowing into the electrodeionization apparatus through the apparatus and degrading the ion exchanger of the electrodeionization apparatus.

  An object of the present invention is to provide a fuel cell water treatment device improved to sufficiently remove fluorine from water flowing into an electrodeionization device.

  II. Since the temperature of the recovered water from the fuel cell is as high as 40 to 65 ° C., organic substances and the like are eluted from the adsorbent that adsorbs and removes the impurities dissolved in the recovered water into the treated water and contaminates the subsequent electrodeionization device. However, there were problems such as causing performance degradation.

  In one aspect of the present invention, an object of the present invention is to provide an improved water treatment device that reduces elution of organic substances from an adsorbent that removes fluorine ions and the like from water flowing into an electrodeionization device. .

  The water treatment device for a fuel cell of the present invention (Claim 1) is a water treatment device for a fuel cell provided with an electrodeionization device for deionizing the recovered water collected from the fuel cell. Fluorine adsorption removing means is provided.

  According to a second aspect of the present invention, there is provided the water treatment apparatus for a fuel cell according to the first aspect, further comprising a decarboxylation unit upstream of the fluorine adsorption removal unit.

  According to a third aspect of the present invention, there is provided the water treatment apparatus for a fuel cell according to the second aspect, further comprising a metal adsorption removal means between the fluorine adsorption removal means and the electrodeionization apparatus.

  According to a fourth aspect of the present invention, there is provided the water treatment apparatus for a fuel cell according to the first aspect, further comprising a decarboxylation means between the fluorine adsorption removal means and the electrodeionization apparatus.

  According to a fifth aspect of the present invention, there is provided the water treatment apparatus for a fuel cell according to the fourth aspect, further comprising a metal adsorption removing unit between the decarboxylation unit and the electrodeionization unit.

  The water treatment device for a fuel cell according to claim 6 is characterized in that, in claim 4, a metal adsorption removal means is provided between the fluorine adsorption removal means and the decarboxylation means.

  According to a seventh aspect of the present invention, there is provided the water treatment apparatus for a fuel cell according to any one of the first to sixth aspects, wherein the fluorine adsorption removing means includes a fluorine adsorption resin, an anion exchange resin, or an alumina compound.

  The water treatment device for a fuel cell according to claim 8 is characterized in that, in claim 7, the fluorine adsorption removal resin or the anion exchange resin has a TOC elution amount of 200 ppb or less.

  The water treatment device for a fuel cell according to claim 9 is characterized in that, in claim 8, the fluorine adsorption removing resin or the anion exchange resin is washed with pure water of 65 ° C. or more.

  The water treatment device for a fuel cell of claim 10 is characterized in that, in claim 3, 5 or 6, the metal adsorption removal means comprises a metal adsorption resin, a chelate resin or a cation exchange resin.

  The water treatment device for a fuel cell of claim 11 is characterized in that, in claim 10, the resin of the metal adsorption removal means has a TOC elution amount of 200 ppb or less.

  The water treatment apparatus for a fuel cell according to claim 12 is characterized in that, in claim 11, the resin is washed with pure water at 65 ° C. or higher.

  A water treatment device for a fuel cell according to a thirteenth aspect is the water treatment device according to any one of the second to twelfth aspects, wherein the decarbonation means is a gas-liquid contact type, and an air supply source to the gas phase side is provided in the fuel cell power generation device. The air supply device to the fuel cell air electrode installed in the fuel cell, and the air collected from the air supply device outlet, or a part or all of the fuel cell air electrode exhaust to the gas phase side of the decarbonation means It is characterized by supplying.

  A fuel cell water treatment device according to a fourteenth aspect is the water treatment device for a fuel cell according to any one of the second to twelfth aspects, wherein the decarbonation means is a membrane type, and an air supply source to the gas phase side is installed in the fuel cell power generator. An air supply device to the air electrode of the fuel cell, which is characterized in that the air collected from the outlet of the air supply device is supplied to the gas phase side of the decarbonation means.

  In the water treatment apparatus for fuel cells of the present invention, fluorine is highly adsorbed and removed from the water from the fuel cell by the fluorine adsorption / removal device, so that the ion exchanger of the electrodeionization device is prevented from being deteriorated by fluorine. In addition, the fuel cell wastewater can be treated stably over a long period of time.

  According to a second aspect of the present invention, a decarbonation means is provided in front of the fluorine adsorption removal means, and according to a fourth aspect, a decarbonation means is provided between the fluorine adsorption removal means and the electrodeionization apparatus.

  The fuel cell recovered water may include water recovered from exhaust gas containing a large amount of carbon dioxide gas such as exhaust gas from a fuel reformer. When treating such recovered water with a water treatment device, the deionization means reduces the load of the electrodeionization device in advance by decarboxylation by decarboxylation means before flowing into the electrodeionization device. Power consumption can be reduced.

  In claim 3, between the fluorine adsorption removal means and the electrodeionization apparatus, in claim 5, between the decarbonation means and the electrodeionization apparatus, and in claim 6, the fluorine adsorption removal means and the decarboxylation apparatus. Metal adsorption removal means are provided between the means.

  Thus, if the metal adsorption removal means is provided on the rear side of the fluorine adsorption removal means and on the front stage side of the electrodeionization apparatus, even if metal ions such as cerium and aluminum are eluted from the fluorine adsorption removal means, Metal ions flowing into the electrodeionization apparatus can be reduced. Thereby, it becomes possible to maintain the performance of the ion exchanger of the electrodeionization apparatus high over a long period of time.

  As described in claim 7, the fluorine adsorption removal means is preferably a fluorine adsorption resin, an anion exchange resin, or an alumina compound (for example, aluminum oxide).

  As claimed in claim 10, the metal adsorption removal means is preferably a metal adsorption resin, a chelate resin or a cation exchange resin.

  As described in claims 8 and 10, it is preferable that these resins have a TOC elution amount of 200 ppb or less, whereby the electrodeionization device is contaminated by the resin, or resin components are mixed into the treated water of the electrodeionization device. It is prevented.

  As described in claims 9 and 12, by washing these resins with pure water of 65 ° C. or higher in advance, unstable bonded molecules and unpolymerized molecules are removed in advance, and elution is reduced to reduce the subsequent electrodeposition. Stable performance can be maintained for a long time by suppressing contamination of the ion device.

  As claimed in claims 13 and 14, a gas-liquid contact type or membrane type decarboxylation device is suitable as the decarboxylation means. It is preferable to supply air to the gas phase side of the decarbonation device using an air supply device to the fuel cell air electrode. Specifically, air is collected from the outlet of the air supply device and supplied to the gas phase side of the decarbonation means. In the case of claim 13, a part or all of the fuel cell air electrode exhaust may be supplied to the gas phase side of the decarbonation means.

  FIG. 1 is a flowchart of a fuel cell water treatment apparatus according to an embodiment. The recovered water such as the condensed water of the fuel cell is treated by the decarboxylation device 1, the fluorine adsorption removal device 2, the metal removal device 3 and the electrodeionization device 4, and the deionized water generated by the electrodeionization device 4 is used as a fuel reformer. Supplied to the quality device.

  This electrodeionization apparatus has a structure in which a cation exchange membrane and an anion exchange membrane are arranged between an anode and a cathode to form a desalting chamber and a concentrating chamber, and the desalting chamber is filled with an ion exchanger. It may be. In this case, the anode chamber and the cathode chamber may be provided independently, and at least one of these electrode chambers may also serve as the concentration chamber.

  In this embodiment, the decarboxylation device 1 is of the air aeration system. The air for aeration is bubbled in the air cleaning device 5 and purified, and then blown into the water in the decarbonation device 1. Drainage from the concentration chamber or electrode chamber of the electrodeionization device 4 is introduced into the air cleaning device 5. The waste water of the air cleaning device 5 is discharged out of the system.

  In the fuel cell water treatment device configured as described above, fluorine is highly adsorbed and removed by the fluorine adsorption / removal device 2 from the fuel cell recovery water, so that the ion exchanger of the electrodeionization device 4 is deteriorated by fluorine. Therefore, the fuel cell wastewater can be treated stably over a long period of time and used as a water source for the fuel reformer.

  In addition, even if metal ions such as cerium or aluminum ions are eluted from the fluorine adsorption / removal device 2, they are removed by the metal removal device 3, so that the performance of the ion exchanger of the electrodeionization device 4 can be maintained high over a long period of time. Is possible.

  Next, water for a fuel cell comprising the pretreatment device in which the decarbonation device, the fluorine adsorption removal device, and the metal removal device are disposed in the casing, and the electrodeionization device 4 attached to the pretreatment device. The processing apparatus will be described with reference to FIGS.

  FIG. 2 is a perspective view of the fuel cell water treatment device as viewed from below, FIG. 3 is a perspective view of the casing with the front cover opened, and FIG. FIG. 5 is a front view showing the configuration of FIG. 4, FIG. 6 is a perspective view of the frame in the air-cleaning chamber, and FIG. 7 is a line VII-VII in FIG. FIG. 8 is a perspective view of a spiral plate in the decarbonation chamber.

  As described above, the fuel cell water treatment apparatus is obtained by integrating the pretreatment apparatus 10 and the electrodeionization apparatus 4. The casing 12 of the pretreatment device 10 has a shallow rectangular parallelepiped shape, and a front cover 14 is attached to the front surface.

  As shown in FIGS. 4 and 5, the waste water from the concentration chamber or electrode chamber of the electrodeionization device 4 is introduced into the air cleaning chamber 20 through the transfer pipe 18, and the air is cleaned. The configuration of the air cleaning chamber 20 will be described in detail later.

  The air cleaned in the air cleaning chamber 20 is introduced from the air inlet 31 to the decarbonation chamber 30, and the water used for cleaning flows out from an outflow hole (not shown) provided on the back surface of the casing 12, and is discarded. Is done.

  To-be-treated water is introduced into the upper part of the decarbonation chamber 30 from a treated water inlet (not shown) on the back surface or upper surface of the casing 12. In the decarbonation chamber 30, the air from the air inlet 31 rises while circling the spiral plate 32, contacts with the water to be treated, and decarboxylates. The spiral passage 34 of the spiral plate 32 is filled with a packing (not shown) having a random structure in which wires are entangled, and the air rises along the spiral plate while being slowly and finely divided. It is configured to perform decarboxylation.

  The decarboxylated water flows into the relay chamber 40 (FIGS. 4 and 7) from the decarboxylation chamber 30 through the advection port 36 (FIG. 5), and from the relay chamber 40 to the advection port 42 (seventh). It flows into the water storage chamber 50 via the figure). As shown in FIG. 7, the relay chamber 40 extends in the vertical direction behind the water storage chamber 50. A water advection port 42 is provided in the upper portion of the relay chamber 40.

  In the water storage chamber 50, float switches 52 and 54 for detecting the water level are provided. If both the float switches 52 and 54 are OFF, the pump 62 described below is stopped.

  The water in the water storage chamber 50 is introduced into the lower portion of the first fluorine removal chamber 70 through the tube 60, the pump 62 driven by the motor 64, and the tube 66, and rises in the chamber 70. Next, water is introduced into the upper portion of the second fluorine removing chamber 72 from the upper portion of the fluorine removing chamber 70 via the advection pipe 71 and descends in the chamber 72. Next, it is introduced into the lower part of the third fluorine removal chamber 74 through the advection port 73 and moves up in the chamber 74.

  Each fluorine removal chamber 70, 72, 74 is filled with fluorine adsorption resin 76 (FIG. 3), and fluorine ions are adsorbed and removed. Instead of the fluorine adsorption resin 76, an alumina compound having fluorine adsorption ability such as alumina silicate can be used.

  The water that has reached the upper part in the third fluorine removal chamber 74 flows from the advection port 78 to the upper part of the first metal removal chamber 80 and descends in the chamber 80. Next, the air flows into the lower part of the second metal removal chamber 82 from the advection port 81 and rises in the chamber 82. The water reaching the upper part of the chamber 82 is introduced into the electrodeionization device 4 through the advection port 84. Although not shown in the drawing, a microfiltration membrane is disposed so as to cover the advection port 84 so that resin fragments do not flow into the electrodeionization device 4.

  Each metal removal chamber 80, 82 is filled with a metal adsorption resin 86, and metal ions are adsorbed and removed.

  In this way, the water decarboxylated, fluorine-removed and metal-removed by the pretreatment device 10 is introduced into the electrodeionization device 4 through the advection port 84.

  In the casing 10, partition plates 90, 92, 94, 96, 98 are extended in the vertical direction in order to partition and form the removal chambers 70, 72, 74, 80, 82. 72, 74, 80, 82 extend in the vertical direction. The tube 66 passes through the partition plate 90, and the advection pipe 71 passes through the partition plate 92. The advection ports 73, 78, 81 are provided in the partition plates 94, 96, 98. The advection port 84 is formed in the side wall of the casing 12.

  Next, the structure of the air cleaning chamber 20 will be described in detail with reference to FIG. 6 (a) and 6 (b) are perspective views seen from opposite directions. In FIG. 6 (b), water staying in the air cleaning chamber 20 is shown.

  The air cleaning chamber 20 is formed between a pair of vertical partition plates 20a and 20b (FIG. 5) provided integrally with the casing 12.

  The air supplied from an air pump (not shown) is blown into the air cleaning chamber 20 through the air tube 21. A frame 22 is installed in the air cleaning chamber 20. The frame 22 includes a surrounding frame portion 23, a hanging plate 24, and a rising plate 25, and a central chamber 26, a water outflow chamber 27, and an air outflow chamber 28 are formed. The end of the tube 21 is inserted into the central chamber 26. Water is introduced into the central chamber 26 via the transfer pipe 18. A drooping plate 24 is provided between the central chamber 26 and the water outflow chamber 27 so as to hang from the upper side of the surrounding frame portion 23, and the water in the central chamber 26 flows around the lower end of the drooping plate 24 and flows out of the water. The water flows into the chamber 27 and flows out of the casing 12 from the upper portion of the water outflow chamber 27 through the overflow port 29. In the central chamber 26 and the water outflow chamber 27, water is accumulated up to the lower edge level of the overflow port 29, and the lower end of the tube 21 is submerged in the water.

  The central chamber 26 and the air outflow chamber 28 are partitioned by a rising plate 25 that rises from the bottom side of the surrounding frame portion 23.

  The air blown into the water from the tube 21 detaches from the water surface, then flows around the upper end of the rising plate 25 and flows into the air outflow chamber 28, and enters the decarbonation chamber 30 through the air inlet 31. Blown and used for decarboxylation as described above.

  9 and 10 are flow charts of a fuel cell water treatment apparatus according to another embodiment of the present invention.

  In FIG. 9, the fluorine adsorption / removal device 2 is arranged on the upstream side of the decarboxylation device 1, and processing is performed in the order of fluorine adsorption removal → decarbonation → metal removal → electric deionization. Other configurations are the same as those in FIG.

  In FIG. 10, in FIG. 9, the decarboxylation device 1 is disposed on the rear stage side of the metal removal device 3, and processing is performed in the order of fluorine adsorption removal → metal removal → decarbonation → electric deionization. Other configurations are the same as those in FIG.

  Even in the fuel cell water treatment apparatus of FIGS. 9 and 10 configured as described above, since fluorine is highly adsorbed and removed by the fluorine adsorption / removal device 2 from the fuel cell recovered water, the ion of the electrodeionization device 4 The exchanger is prevented from being deteriorated by fluorine, and the fuel cell waste water can be stably treated over a long period of time and used as a water source for the fuel reformer.

  In addition, even if metal ions such as cerium or aluminum ions are eluted from the fluorine adsorption / removal device 2, they are removed by the metal removal device 3, so that the performance of the ion exchanger of the electrodeionization device 4 can be maintained high over a long period of time. Is possible.

  Fluorine adsorption resin and anion exchange resin used for fluorine adsorption removal means, metal adsorption resin, chelate resin, and cation exchange resin used for metal adsorption removal means are unstable molecules in the inside. It has unpolymerized molecules, and when the temperature rises, the molecules in an unstable bond state and the unpolymerized molecules are eluted from the resin into water.

  Since the temperature of the fuel cell recovered water rises to about 65 ° C., the amount of effluent from the fluorine adsorption removal means and metal adsorption removal means placed in front of the electrodeionization apparatus increases, and the ion exchanger of the electrodeionization apparatus In addition to degrading the performance, it also flows into the treated water and lowers the purity of the treated water.

  The main effluent from the filler is TOC. Therefore, it is possible to use the TOC elution amount as an indicator of the cleanliness of the filler. By using a filler having a TOC elution amount of 200 ppb or less, contamination of the electrodeionization apparatus, TOC component in the treated water Can be prevented. Here, the TOC elution amount is a value obtained by (inlet TOC concentration) − (outlet TOC concentration).

  In the present invention, the metal removing device 3 may be omitted in the flow shown in FIGS.

  In the present invention, the decarbonation means may be a gas-liquid contact type other than the aeration type as described above. For example, a decarboxylation tower that sprinkles water from the upper part of the tower and sends air from the lower part can be used. The decarboxylation means may be a membrane type.

  As an air supply source used for the decarbonation means, an air supply device provided in the fuel cell power generator to the fuel cell air electrode may be used. In this way, it is not necessary to provide an air supply source such as a blower, a fan, or a compressor inside the water treatment apparatus, and the apparatus can be miniaturized. Further, in the gas-liquid contact type, exhaust containing generated water generated by reaction inside the fuel cell can be used. In this case, the generated water in the exhaust gas to be used can be taken in by gas-liquid contact, so that the recovered water utilization rate of the fuel cell power generator can be improved.

  Note that each of the above embodiments is an example of the present invention, and the present invention may take forms other than those shown in the drawings.

It is a flowchart of the water treatment apparatus for fuel cells which concerns on embodiment. It is a perspective view of the state looked up from the downward direction of the water treatment apparatus for fuel cells of FIG. It is a perspective view of the state which opened the front cover of the casing of FIG. It is a perspective view of the state which removed the fluorine adsorption resin and the metal adsorption resin from FIG. It is a front view which shows the structure of FIG. It is a perspective view of the flame | frame in a cleansing chamber. It is the VII-VII sectional view taken on the line of FIG. It is a perspective view of the spiral board in a decarbonation chamber. It is a flowchart of the water treatment apparatus for fuel cells which concerns on another embodiment. It is a flowchart of the water treatment apparatus for fuel cells which concerns on another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pretreatment apparatus 12 Casing 18 Transfer pipe 20 Air washing room 21 Air blowing tube 22 Frame 30 Decarbonation room 32 Spiral plate 50 Storage room 62 Pump 70,72,74 Fluorine removal room 76 Fluorine adsorption resin 80,82 Metal removal room 86 Metal adsorption resin

Claims (14)

In a fuel cell water treatment device comprising an electrodeionization device for deionizing recovered water recovered from a fuel cell,
A water treatment apparatus for a fuel cell, comprising a fluorine adsorption removing means in a front stage of the electrodeionization apparatus.   The water treatment apparatus for a fuel cell according to claim 1, further comprising a decarboxylation means upstream of the fluorine adsorption removal means.   3. The water treatment apparatus for a fuel cell according to claim 2, further comprising a metal adsorption removal means between the fluorine adsorption removal means and the electrodeionization apparatus.   2. The water treatment apparatus for a fuel cell according to claim 1, further comprising a decarboxylation means between the fluorine adsorption removal means and the electrodeionization apparatus.   5. The water treatment apparatus for a fuel cell according to claim 4, further comprising a metal adsorption removing means between the decarbonation means and the electrodeionization apparatus.   5. The water treatment apparatus for a fuel cell according to claim 4, further comprising a metal adsorption removal means between the fluorine adsorption removal means and the decarbonation means.   7. The water treatment apparatus for a fuel cell according to claim 1, wherein the fluorine adsorption removing unit includes a fluorine adsorption resin, an anion exchange resin, or an alumina compound.   8. The water treatment apparatus for a fuel cell according to claim 7, wherein the fluorine adsorption removal resin or the anion exchange resin has a TOC elution amount of 200 ppb or less.   9. The water treatment apparatus for a fuel cell according to claim 8, wherein the fluorine adsorption removing resin or anion exchange resin is washed with pure water at 65 ° C. or higher.   7. The water treatment device for a fuel cell according to claim 3, 5 or 6, wherein the metal adsorption removing means comprises a metal adsorption resin, a chelate resin or a cation exchange resin.   11. The water treatment apparatus for a fuel cell according to claim 10, wherein the resin of the metal adsorption removing means has a TOC elution amount of 200 ppb or less.   The water treatment apparatus for a fuel cell according to claim 11, wherein the resin is washed with pure water of 65 ° C or higher.   13. The fuel cell air electrode according to any one of claims 2 to 12, wherein the decarboxylation means is a gas-liquid contact type, and an air supply source to the gas phase side thereof is installed in the fuel cell power generator. A fuel cell water treatment, characterized in that it is an air supply device and supplies part or all of the air collected from the outlet of the air supply device or the fuel cell air electrode exhaust to the gas phase side of the decarbonation means apparatus.   13. The air supply to a fuel cell air electrode according to any one of claims 2 to 12, wherein the decarboxylation means is a membrane type, and an air supply source to the gas phase side is installed in the fuel cell power generator. A water treatment device for a fuel cell, characterized in that the air collected from the outlet of the air supply device is supplied to the gas phase side of the decarbonation means.

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