JP2005116184A - Water treatment device for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment device for a fuel cell used for subjecting recovery water from the fuel cell to a decarboxylation treatment and an electric deionization treatment at a low cost. <P>SOLUTION: Drainage from an negative electrode chamber of an electric deionization device 4 is introduced into a central chamber 26 of an air-cleaning chamber 20 through a transfer pipe 18; and air is cleaned by injecting the air into it through a tube 21. The cleaned air is injected into a decarboxylation chamber 30, and the recovery water of the fuel cell is subjected to a decarboxylation treatment. The recovery water is sequentially run through fluorine removal chambers 70, 72 and 74 and metal removal chambers 80 and 82 via a pump 62, and supplied to the deionization chamber 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a water treatment device for a fuel cell for treating raw water such as recovered water from a fuel cell with an electrodeionization device and supplying it to a fuel cell system.

  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. The exhaust gas from the fuel cell contains electrochemically generated water vapor and carbon dioxide, and the condensed water obtained by cooling the exhaust gas and performing gas-liquid separation also contains a carbonic acid component. Therefore, if this condensed water is treated as it is, this carbon dioxide gas also becomes a load of the ion exchange resin, which causes an increase in the exchange frequency of the ion exchange resin. In addition, carbonate ions may be difficult to remove with an electrodeionization apparatus. Therefore, in the apparatus of each of the above publications, the recovered water is treated with an electrodeionization apparatus after being decarboxylated.

  In the former Japanese Patent Laid-Open No. 9-161833, the waste water of a phosphoric acid fuel cell is treated by a decarbonation tower and a microfiltration membrane separation, and then treated by an electrodeionization apparatus.

In the latter Japanese Patent Application Laid-Open No. 2001-232394, the waste water of the polymer electrolyte fuel cell is decarboxylated by an air contact type or gas membrane permeation type decarboxylation means, followed by reverse osmosis treatment, and then electrodeposition. It is processed with an ion device. In this polymer electrolyte fuel cell, a fluorine-based cation exchange membrane is used as the solid electrolyte, and the fuel cell wastewater contains a small amount of fluorine ions. Therefore, in order to prevent the ion exchanger in the electrodeionization apparatus from deteriorating due to fluorine, it is desirable that the water treatment apparatus for fuel cells is provided with a fluorine removing means in front of the electrodeionization apparatus.
JP-A-9-161833 JP 2001-232394 A

  The decarboxylation tower employed in the above-mentioned JP-A-9-161833 requires a tower having a remarkably large volume. The gas membrane permeation type decarboxylation apparatus employed in the above Japanese Patent Application Laid-Open No. 2001-232394 is expensive.

  The present invention removes carbonic acid from the water flowing into the electrodeionization apparatus at low cost, and removes turbidity, microorganisms, etc. mixed in the gas to prevent clogging after the decarbonation apparatus. An object of the present invention is to provide a water treatment device for a fuel cell that can be used.

  A water treatment apparatus for a fuel cell according to the present invention includes a decarbonation apparatus that decarboxylates raw water, a pretreatment means that performs a metal adsorption treatment after treating the treated water from the decarbonation apparatus with a fluorine adsorption, and the pretreatment means. A water treatment device for a fuel cell having an electrodeionization device for deionizing water from the water, wherein the decarboxylation device blows a gas into raw water to perform a decarboxylation treatment. In the preceding stage, a gas cleaning device for purifying the gas is provided, and the gas cleaning device cleans the gas by contacting the drainage of the electrodeionization device or surplus condensed water generated from the fuel cell. It is characterized by being.

  In such a water treatment device for fuel cells, it is possible to produce high-quality treated water by treating fuel cell wastewater with a decarbonation treatment, a fluorine removal treatment and a metal fluorine removal treatment, and then treating with an electrodeionization device. it can. This treated water is suitable for fuel cell fuel reforming and the like. In this fuel cell water treatment device, since fluorine is removed, deterioration of the ion exchange resin of the electrodeionization device is prevented.

  This decarboxylation process is performed by blowing a gas into the raw water, and the configuration is simple. Moreover, since the gas used for this decarboxylation process is washed with water and dust in the air (atmosphere) is dedusted, the decarboxylation process water is not contaminated.

  This air washing treatment is to bring the electrodeionization device wastewater into contact with the gas, and can effectively utilize the drainage of the electrodeionization device.

  The air cleaning device includes a central chamber into which the drainage of the electrodeionization device is introduced and the gas is blown into water, a water outflow chamber that communicates with a lower portion of the central chamber, and into which water flows from the central chamber. And a water overflow port provided in the upper part of the water outflow chamber, and preferably configured so that a gas desorbed from the water surface in the central chamber is supplied to the decarboxylation device.

  In this air cleaning apparatus, water is stored in the central chamber up to the level of the overflow port. For this reason, the blowing depth of gas can be made as designed, and the gas can be sufficiently purified.

  According to the water treatment apparatus for a fuel cell of the present invention, decarboxylation is performed at low cost.

  Note that metal ions such as cerium and aluminum ions may be eluted from members provided on the front side of the electrodeionization apparatus such as a fluorine adsorption removal apparatus. Since the metal removal device is provided after the fluorine removal device and before the electrodeionization device, the amount of metal flowing into the electrodeionization device is reduced, and the ion exchanger performance of the electrodeionization device is maintained high over a long period of time. be able to.

  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.

  A preferred embodiment of the air cleaning device 5 will be described in detail later.

  The decarbonation device 1 includes a spiral plate 32 shown in FIG. 8 to be described later, and a filler filled in the spiral flow path of the spiral plate 32. This configuration will be described later in detail.

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

  Further, the decarbonation device 1 is composed of a spiral plate and a filler, and is excellent in decarbonation characteristics while being small. For this reason, the load of the electrodeionization apparatus 4 is small.

  The gas (air) supplied to the decarbonation device 1 is dust-removed by the air cleaning device 5, and the raw water (recovered water) is prevented from being contaminated. This air washing device 5 is for washing with the drainage of the electrodeionization device 4, and the drainage of the electrodeionization device 4 is effectively reused.

  In this fuel cell water treatment device, even if metal ions such as cerium and aluminum ions are eluted from the fluorine adsorption removal device 2, they are removed by the metal removal device 3. For this reason, it becomes possible to maintain the performance of the ion exchanger of the electrodeionization apparatus 4 high over a long period of time.

  Next, a pretreatment device in which the air cleaning device, the decarbonation device, the fluorine adsorption removal device, and the metal removal device are arranged in a casing, and an electrodeionization device 4 attached to the pretreatment device are provided. A fuel cell water treatment 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 cross-sectional view, FIG. 8 is a perspective view of a spiral plate in the decarbonation chamber, and FIG. 9 is a schematic view of a filler.

  As described above, the fuel cell water treatment apparatus is obtained by integrating the pretreatment apparatus 10 having the decarbonation apparatus 1 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.

  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. Infused and used for decarboxylation.

  The air cleaned in the air cleaning chamber 20 is introduced from the air introduction port 31 to the decarbonation chamber 30 in which the decarboxylation device is installed, and the water used for the cleaning is an outflow hole (illustrated) provided in the back surface of the casing 12. Abbreviated) and discarded.

  The decarbonation device in the decarbonation chamber 30 includes a spiral plate 32 and a filler.

  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 random three-dimensional structure filling 33 entangled with a synthetic resin or metal wire schematically shown in FIG. It rises along the spiral plate while being divided, and is configured to be sufficiently decarboxylated. The diameter of this wire is preferably about 0.05 to 0.5 mm. The average diameter of the passage between the wires of the filler is preferably about 2 to 10 mm, particularly about 3 to 7 mm.

  The spiral plate 32 is obtained by connecting a bent metal plate with slits in multiple stages by welding or the like, and a long and narrow partition plate is vertically passed through the axial center portion of the spiral. The height of the spiral per step is preferably about 5 to 10 mm.

  In this embodiment, since the decarbonation chamber 30 has a rectangular parallelepiped shape, the metal plate constituting each step of the spiral plate 32 has a rectangular shape. However, if the decarboxylation chamber is cylindrical, the spiral plate is It is a screw screw.

  The decarbonation chamber 30 has a height of 100 mm, a depth and a width of 50 mm, a seven-stage spiral plate 32 is arranged as shown in the figure, and a filler having an average opening diameter of about 5 mm is filled into the spiral flow path. When water having a water temperature of 5 ° C. and a carbon dioxide concentration of 80 ppm was passed through the decarboxylation apparatus at 40 mL / min and air was diffused at 2000 mL / min, the carbon dioxide concentration of the treated water was found to be 10 ppm or less. .

  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. In place of the fluorine adsorbing resin, an alumina compound having fluorine adsorbing ability such as alumina silicate can also 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.

  In addition, the said embodiment is an example of this invention and this invention can take forms other than illustration. For example, in the above embodiment, the drainage of the electrodeionization device 4 is supplied to the air cleaning chamber 20, but condensed water generated in the fuel cell system may be supplied.

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 typical perspective view of a filling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pretreatment apparatus 12 Casing 18 Transfer pipe 20 Washing room 20a, 20b Partition plate 21 Air blowing tube 22 Frame 23 Enclosure part 24 Drooping plate 25 Standing plate 26 Central chamber 27 Water outflow chamber 28 Air outflow chamber 29 Overflow Port 30 Decarbonation chamber 32 Spiral plate 33 Filling 50 Storage chamber 62 Pump 70, 72, 74 Fluorine removal chamber 76 Fluorine adsorption resin 80, 82 Metal removal chamber 86 Metal adsorption resin

Claims (2)

A decarbonation apparatus for decarboxylating raw water, a pretreatment means for removing metal after treatment of the treated water from the decarbonation apparatus by fluorine adsorption, and an electrodeionization treatment for deionizing water from the pretreatment means. A water treatment device for a fuel cell having an ion device,
The decarboxylation device is for decarboxylation by blowing gas into raw water,
A scrubber for purifying the gas is provided upstream of the decarbonator,
The water cleaning device for a fuel cell is characterized in that the air cleaning device purifies the waste water of the electrodeionization device or surplus condensed water generated from the fuel cell by bringing the gas into contact therewith. The air cleaning device according to claim 1,
A central chamber into which drainage of the electrodeionization apparatus is introduced and the gas is blown into water;
A water outflow chamber that communicates with the lower portion of the central chamber and from which water is transferred;
An overflow port provided in the upper part of the water outflow chamber;
The fuel cell water treatment device is characterized in that the gas desorbed from the water surface in the central chamber is supplied to the decarboxylation device.

Images