JP2004149890A - Dehumidification mechanism, and dehumidification method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more reduce the production cost of the gas to be treated by improving the efficiency of dehumidification treatment for a cathode gas and/or an anode gas (the gas to be treated) produced by utilizing electrolysis. <P>SOLUTION: In the dehumidification mechanism, a cathode gas or an anode gas as the gas to be treated produced by utilizing electrolysis is subjected to dehumidification. The dehumidification mechanism is provided with a dehumidification device where a dehumidification agent performing the dehumidification of the gas to be treated is housed in a vessel body. The vessel body is provided with a cooling trace for flowing a gas for cooling. Preferably, either the cathode gas or anode gas is regarded as the gas to be treated, and the gas for cooling is regarded as the other to the cathode gas or the anode gas. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dehumidifier and a dehumidifying method for dehumidifying a cathode gas and / or an anode gas generated by using electrolysis, and more particularly to a hydrogen gas and / or oxygen generated by using electrolysis of water. The present invention relates to a dehumidifying mechanism and a dehumidifying method for dehumidifying gas.
[0002]
[Prior art]
2. Description of the Related Art A method of generating a cathode gas (for example, hydrogen) and an anode gas (for example, oxygen) using electrolysis (hereinafter, also referred to as electrolysis) has been known. Such a gas generation method is widely used because a high-purity generated gas can be produced each time it is used, and it is not necessary to store the gas in a tank such as a cylinder or a cold evaporator, and to improve safety. I have.
By the way, when the cathode gas and the anode gas are generated by using the electrolytic action, the generated gas is in a wet state containing a large amount of moisture. Therefore, in general, when the cathode gas and the anode gas are generated by utilizing the electrolytic action, a dehumidifying mechanism for a generated gas in a wet state (hereinafter, also referred to as a gas to be treated) is provided.
[0003]
Conventionally, as a dehumidifying mechanism for dehumidifying such a gas to be treated, there are provided two or more dehumidifiers filled with a dehumidifier, and when dehumidifying the gas to be treated by one dehumidifier, the other dehumidifier dehumidifies the gas. Those configured to allow regeneration of the agent are used. Then, by using such a dehumidifier by alternately switching between dehumidification and regeneration every predetermined time, a dry gas to be treated is continuously supplied.
[0004]
By the way, the dehumidifying agent used in this type of dehumidifying mechanism generally exhibits a predetermined dehumidifying performance at about room temperature, and is regenerated by heating to a high temperature. It is necessary to repeat heating and cooling. That is, the amount of the dehumidifier used is determined using the time required for regeneration of the dehumidifier as one calculation reference. Therefore, in order to reduce the amount of the dehumidifier, it is necessary to heat and cool the dehumidifier as quickly as possible.
[0005]
Further, since the gas to be processed generated by using electrolysis is required to have high purity as in a cylinder or the like, it is necessary to prevent the gas purity from being reduced by a dehumidifying mechanism.
[0006]
Therefore, in the prior art, by removing a part of the gas to be treated that has been dehumidified by another dehumidifier to one dehumidifier during heating, the moisture is removed from the dehumidifier. I have. Further, even during cooling, the dehumidifier is cooled by supplying a part of the gas to be processed which has been dehumidified by another dehumidifier (Patent Document 1).
[0007]
Further, when the amount of water to be removed is large, a large amount of dehumidifying agent is required, and the apparatus is also increased in size. Therefore, the regeneration time is sufficiently reduced only by cooling using a part of the gas to be treated. And the waste gas is wasted. Therefore, in order to reduce the load on the dehumidifying device and reduce the size of the device, a method of installing a gas cooler for cooling the gas to be treated and condensing and removing moisture is provided in a stage preceding the dehumidifying device.
[0008]
[Patent Document 1]
JP-A-57-105226
[Problems to be solved by the invention]
However, in the prior art as described above, although the inside of the dehumidifier can be maintained at high purity by using the gas to be treated itself for cooling, the gas to be treated after use is released to the atmosphere as a purge gas, Alternatively, it is necessary to dehumidify and pressurize again to reuse the gas, and in any case, there is a problem that the cost of generating the gas to be treated increases.
[0010]
Further, even when a gas cooler is used, the effect of cooling to condense and remove moisture is not sufficient just by using cooling tower water, which becomes about 32 ° C. in summer, as a cooling medium. Unless the chiller water is used as a refrigerant, it is not possible to effectively condense and remove water so that the dehumidifier can be substantially reduced.
However, the operation of the chiller requires a lot of energy, and also requires various accessories such as a drain pot for condensed water, resulting in various problems that the equipment configuration becomes very large and the equipment price increases. is there.
[0011]
In addition, the gas generation method using electrolysis is manufactured each time it is used in a demand destination, or is operated so as to adjust the generation amount according to the usage amount. Therefore, if the amount of generated gas is small, it is considered that the dehumidifying agent still has a sufficient dehumidifying ability. Nevertheless, if the switching operation between the dehumidifying and the regenerating is performed every predetermined time as described above, the heating is performed. Energy and purge gas are wasted.
[0012]
Therefore, the present invention is to improve the efficiency of dehumidification of the cathode gas and / or the anode gas (gas to be treated) generated by using electrolysis, thereby further reducing the production cost of the gas to be treated. Make it an issue.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, the present invention is a dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas or an anode gas generated by using electrolysis, and a dehumidifier for dehumidifying the gas to be treated. Is provided with a dehumidifying device accommodated in a container main body, and a cooling trace for conducting a cooling gas is provided in the container main body.
In the dehumidifying mechanism, preferably, the gas to be treated is one of a cathode gas and an anode gas, and the cooling gas is the other of the cathode gas and the anode gas.
[0014]
Further, the present invention is a dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by utilizing electrolysis, wherein the dehumidifying agent for dehumidifying the gas to be treated is a container main body. And a dehumidifying device that is housed in the container and is used by switching between a dehumidifying step and a regenerating step, wherein a hollow portion not containing a dehumidifying agent is formed at a lower portion of the container body. I do.
[0015]
Further, the present invention is a dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis, wherein the dehumidifying agent for dehumidifying the gas to be treated is a container main body. And a dehumidifying device which is housed in the container and is used by switching between a dehumidifying step and a regenerating step, wherein the container main body is supported by a measuring instrument.
[0016]
Further, the present invention is a dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by utilizing electrolysis, wherein the gas to be treated and water are provided at a stage preceding the dehumidifier. And a gas cooler for cooling the gas to be treated separated in the separation tank, wherein water condensed in the gas cooler naturally flows down to the separation tank. A dehumidifying mechanism is provided.
[0017]
Further, the present invention is a dehumidification method for dehumidifying a gas to be treated of a cathode gas or an anode gas generated by using electrolysis, and a dehumidification step of dehumidifying one of the gases to be treated with a dehumidifier. A regenerating step of heating and regenerating the dehumidifying agent, wherein in the regenerating step, the heated dehumidifying agent is indirectly cooled by the other of the gas to be treated. I do.
[0018]
Further, the present invention is a dehumidifying method for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis, wherein a dehumidifying step of dehumidifying the gas to be treated with a dehumidifying agent; A regenerating step of heating and regenerating the dehumidifying agent, and switching between the dehumidifying step and the regenerating step based on the weight of the dehumidifying agent measured in the dehumidifying step and / or the regenerating step. The present invention provides a dehumidification method characterized by the following.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
FIG. 1 is a flowchart showing one embodiment of the dehumidifying mechanism of the present invention. As shown in FIG. 1, the dehumidifying mechanism 1 of the present embodiment dehumidifies the hydrogen gas by using a hydrogen gas, which is a cathode gas generated by a water electrolysis module, as a gas to be treated. The hydrogen gas is configured to be supplied to the dehumidifier 1 via the gas separator and the gas cooler.
[0021]
The water electrolysis module is, for example, configured by stacking a plurality of electrolysis cells in which an electrode plate and a power supply are stacked on both sides of a solid polymer electrolyte membrane, and pure water supplied to the anode side is used. Electrolysis generates hydrogen gas as a cathode gas and oxygen gas as an anode gas.
[0022]
FIG. 2 is a schematic diagram showing the positional relationship between the gas separator 40 and the gas cooler 50 disposed at the preceding stage of the dehumidifier, that is, between the water electrolysis module and the dehumidifier. As shown in FIG. 2, the gas cooler 50 is disposed above the gas separator 40, and a pipe extending from the gas separator 40 to the gas cooler 50 faces upward (horizontal) toward the gas cooler 50. ), That is, the water condensed in the gas cooler 50 naturally flows down to the separation tank 40.
[0023]
The gas separator 40 and the gas cooler 50 are not particularly limited, and those having a known device configuration can be used. As the gas cooler 50, for example, a plate type that introduces cooling water in a countercurrent flow is used. A heat exchanger can be suitably used.
In addition, the gas to be treated generated by the water electrolysis module generally has a temperature of about 45 ° C. and a dew point of about 45 ° C. In consideration of the capacity of a dehumidifier provided in a subsequent stage, the gas cooler 50 is It is preferable that the temperature of the gas to be treated be about 35 ° C. and the dew point be about 35 ° C.
[0024]
In this embodiment, as shown in FIG. 1, the dehumidifier 10 includes a first dehumidifier and a second dehumidifier arranged in parallel, and when one is in the dehumidification process, the other is in the regeneration process. It is configured to be. Therefore, when the first dehumidifier is in the dehumidification process and the second dehumidifier is in the regeneration process, the hydrogen gas that has exited the gas cooler is supplied to the first dehumidifier and dehumidified to a predetermined dew point. , And supplied to the demand destination. Further, in that case, part of the hydrogen gas dehumidified by the first dehumidifier is supplied to the second dehumidifier in the regeneration step from the reverse direction of the dehumidification step, and is used for regeneration and cooling of the dehumidifier. After that, the gas is discharged as a purge gas.
Further, a cooling gas is supplied to the second dehumidifier in the regeneration step.
[0025]
FIG. 3 is a front view showing the configuration of the dehumidifying apparatus 10 by a partial cross section. As shown in FIG. 3, the dehumidifier 10 includes a container main body 11 containing a dehumidifier 20 therein, a hydrogen gas supply pipe 12a provided on both upper and lower ends of the container main body 11, and a hydrogen gas discharge pipe 12a. It comprises a pipe 12b, cooling traces 13 arranged on the outer surface of the container body 11 at substantially equal intervals, and heating wires 15 also arranged at substantially equal intervals in the spiral gap of the cooling traces. .
[0026]
In addition, a cavity 16 in which the dehumidifying agent 20 is not stored is formed in a lower portion of the container body 11.
[0027]
A part of the hydrogen gas supply pipe 12a and a part of the hydrogen gas discharge pipe 12b, and a part of the supply side and the discharge side of the cooling trace 13 are each formed of a deformable flexible hose, and the lower part of the dehumidifier 10 is disposed. The supporting plate for supporting is provided with a slide mechanism 31 that allows the container main body 11 to be vertically movable with respect to a fixing member (not shown).
The dehumidifier 10 is supported by a weighing device 30 in a state of being suspended from above, and detects the weight change of the dehumidifier 20 as needed by measuring the total weight including the container body 11 and the like. Is configured to obtain.
[0028]
The cooling trace 13 is for indirectly cooling the dehumidifying agent 20 housed inside the container body 11 with a cooling gas. Specifically, a metal pipe made of stainless steel or copper is provided outside the container body 11. It is attached to the surface by welding or clipping. When the container body 11 is cylindrical, for example, as shown in FIG. 3, the cooling traces 13 are preferably arranged in a spiral along the outer peripheral surface of the cylindrical container body 11.
[0029]
In addition, compressed air can be used as a cooling gas to be conducted to the cooling trace 13, but preferably, the other gas generated by the water electrolysis module is used. Therefore, for example, when hydrogen gas is dehumidified as a gas to be treated as in the present embodiment, it is preferable to use oxygen gas generated by a water electrolysis module as a cooling gas.
[0030]
As the heating wire 15, a known wire such as a sheathed heater in which a heating wire is held by an insulator in a thin metal tube can be used. For example, the heating wire 15 is attached to the container body 11 by clipping and heating cement. .
[0031]
On the other hand, the dehumidifier 20 for dehumidifying the gas to be treated is not particularly limited, and a general dehumidifier such as synthetic zeolite or activated alumina can be used.
[0032]
Next, an operation method of the dehumidifier 11 of the embodiment will be described.
First, the hydrogen gas sent to the dehumidifier 10 in the dehumidification process is supplied into the container main body 11 from the hydrogen gas supply pipe 12a at the lower part of the container main body 11, and after being dehumidified by the dehumidifier 20 to a predetermined dew point, The hydrogen gas is discharged to the outside of the container body 11 from the upper hydrogen gas discharge pipe 12b. In the dehumidifying step, the cooling by the cooling trace 13 and the heating by the heating wire 15 are not indispensable. For example, when the dehumidifying agent generates heat by dehumidifying, in order to suppress the temperature rise of the dehumidifying agent. A cooling gas may be conducted to the cooling trace 13.
[0033]
Then, the hydrogen gas discharged from the dehumidifier 10 is supplied to a demand destination. As shown in FIG. 1, a part of the hydrogen gas is sent to the dehumidifier 10 in the regeneration step.
[0034]
More specifically, the regeneration step of the dehumidifier 10 includes a heating step of removing moisture by heating the dehumidifier, and a cooling step of cooling the heated dehumidifier to about room temperature. Each step in the dehumidifier 10 of this embodiment as shown in FIG. 3 will be described. In the heating step, the entire container body 11 is heated by the heating wire 15, and in the cooling step, the cooling gas is supplied to the cooling trace 13. It is conducted and cooled until the dehumidifying agent 20 recovers the predetermined dehumidifying performance.
In the regeneration step, a part of the dehumidified hydrogen gas is supplied from the hydrogen gas discharge pipe 12b to the container body 11, and after the dehumidifier 20 is removed or cooled, the hydrogen supply pipe 12a is removed. And is released as a purge gas.
[0035]
The dehumidifier 10 of the present embodiment is operated so that the weight from the start of dehumidification in the dehumidification process is continuously measured by the measuring device 30 and the dehumidification process and the regeneration process are switched based on the measured weight. Is done. More specifically, the weight of the entire dehumidifier 10 when the dehumidifier 20 housed in the container body 11 absorbs water and breaks through is measured in advance by the measuring device 30, and the weight is measured in the dehumidification process. When the measured weight reaches a predetermined weight (for example, 95% of the weight at breakthrough), the dehumidification step and the regeneration step are switched.
Preferably, the weight may be measured by the weighing device 30 in the same manner as in the heating in the regeneration step, and the heating may be stopped when the weight in the dry state becomes substantially the same as the previously measured weight.
[0036]
According to the dehumidifying mechanism and the dehumidifying method of the present embodiment, the following effects can be obtained. That is, since the water condensed in the gas cooler 50 flows down naturally to the separation tank 40, the condensed water can be effectively reused as pure water without being discharged to the outside as a purge. It becomes possible. Further, not only can the apparatus configuration be simplified and the cost can be reduced, but also the purity of the high-purity hydrogen gas generated by the water electrolysis can be reduced since the device is reliably shielded from the outside.
[0037]
In addition, since the cavity 16 in which the dehumidifier 20 is not accommodated is formed in the lower part of the container body 11, water generated by condensation in the dehumidification step is temporarily stored in the cavity 16 and then regenerated. In the process, it can be discharged from the hydrogen supply pipe 12a together with the purge gas. As described above, by providing the dehumidifying device 10 with the drain function, it is not necessary to install a drain device between the gas cooler and the dehumidifying device, so that the device can be simplified and the gas purity can be maintained. .
Further, by setting the cavity 16 to have a capacity sufficiently larger than the amount of water generated by condensation between the cooler and the dehumidifier, it is possible to prevent the dehumidifier from being immersed by the water generated by the dehumidification in the dehumidification process. can do.
[0038]
Further, in the dehumidifying mechanism of the present embodiment, since the dehumidifying device 10 having the cooling trace for conducting the cooling gas is used, the container body 11 at high temperature is not rapidly cooled, and the temperature difference is not increased. , For example, the occurrence of fatigue cracks due to thermal fatigue can be prevented. Further, since the dehumidifier is indirectly cooled, there is no possibility that the purity of the hydrogen gas is reduced.
[0039]
Further, the cooling trace has the following advantages over the cooling method using a jacket. That is, in the jacket, the cooling gas bypasses from the inlet to the outlet or stagnates, and the entire container is cooled unevenly, but in the cooling trace, since the cooling gas flows along the tube, the entire container is cooled. It can be cooled uniformly. At the same flow rate, the cooling trace has a higher outlet temperature of the cooling gas than the jacket, and has excellent cooling efficiency.
Also, if the jacket is to be cooled at the same efficiency and uniformly with the jacket, it is necessary to provide a large number of very fine partitioning plates inside the jacket, and furthermore, an electric heater must be penetrated through the partitioning plates. It becomes very complicated. On the other hand, in the cooling trace, since the tube is simply wound around the container body, there is an effect that the production is very simple.
In addition, the jacket which is a double cylinder has a large thermal stress and is inferior in durability. Further, a bellows is required to release the thermal stress, which leads to an increase in cost and size. On the other hand, since the cooling trace is formed by winding a tube, thermal stress can be easily released and the durability is excellent without increasing the cost or the size.
[0040]
Therefore, at the time of cooling, by passing the cooling gas through the cooling trace as described above, the dehumidifying agent can be quickly cooled, and the cooling process can be greatly shortened. Such a shortening of the cooling step not only can reduce the amount of the dehumidifying agent, but also can significantly reduce the energy consumption for regeneration and the amount of purge gas, so that the gas generation efficiency of the water electrolysis apparatus is remarkably increased. It will be improved.
[0041]
For example, using a dehumidifier in which a dehumidifier (synthetic zeolite) is filled in a cylindrical dehumidifier body (about 10 cm in diameter and about 1 m in length) and comparing the cooling time from 300 ° C., nothing flows through the cooling trace. In some cases, only about 200 hours after about 3 hours, and only about 150 hours after about 5 hours. If compressed air flows through the cooling trace, cool to about 50 ° C after about 3 hours. Is possible.
[0042]
Furthermore, the other oxygen gas generated by the water electrolysis module contains a large amount of water and has a large heat capacity like hydrogen gas. Cooling can be performed efficiently.
Also, air can be sucked by an ejector using the pressure and flow rate of oxygen gas, and the air can be used as a cooling gas. In this case, since the air flow rate increases (3 to 7 times), cooling can be performed more efficiently.
In this way, by efficiently cooling the dehumidifier by the cooling trace, the cooling time can be reduced, and the amount of hydrogen gas (purge gas) consumed in the regeneration step can be reduced as much as possible.
[0043]
Furthermore, in the dehumidifying mechanism of the present embodiment, since the dehumidifying device 10 is operated to switch between the dehumidifying step and the regeneration step based on the weight measured by the measuring device 30, the amount of hydrogen gas generated is small. A remarkable effect of reducing the frequency of switching between the dehumidifying step and the regenerating step, reducing the heat energy consumed in the regenerating step and the amount of purge gas, and suppressing the deterioration frequency of the dehumidifying agent to reduce the frequency of replacement. To play.
[0044]
In addition, since heating can be stopped based on the weight measurement result by the weighing device 30 during heating in the regeneration step, waste of thermal energy in the regeneration step can be prevented.
[0045]
In the above embodiment, the case where the hydrogen gas as the cathode gas is used as the gas to be processed is described. However, the oxygen gas as the anode gas may be used as the gas to be processed as a matter of course. Further, other cathode gas and anode gas generated by electrolyzing an electrolytic solution other than pure water can be used as the gas to be treated.
[0046]
Although a flexible hose is used for a part of the hydrogen gas supply pipe and a part of the discharge pipe, a swivel pipe joint may be used to make the pipe movable vertically.
Further, the weighing device 30 may be arranged below the dehumidifier 10.
[0047]
【The invention's effect】
As described above, according to the dehumidifying mechanism and the dehumidifying method according to the present invention, the dehumidifying treatment of the cathode gas and / or the anode gas generated by using the electrolysis can be performed efficiently, and the cathode gas and the anode It is possible to further reduce the gas generation cost.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an embodiment of a dehumidifying mechanism according to the present invention.
FIG. 2 is a schematic diagram showing a positional relationship between a gas separator and a gas cooler.
FIG. 3 is a front view showing a partial cross section of an embodiment of a dehumidifying device used in the dehumidifying mechanism according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dehumidifying mechanism 10 Dehumidifying device 11 Container main body 13 Cooling trace 15 Heating wire 20 Dehumidifying agent 30 Meter 40 Gas separator 50 Gas cooler

Claims (7)

A dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis,
Dehumidifier for dehumidifying the gas to be treated is provided with a dehumidifier contained in a container body,
A dehumidifying mechanism, wherein a cooling trace for conducting a cooling gas is provided in the container body. The dehumidifying mechanism according to claim 1, wherein the gas to be processed is one of a cathode gas and an anode gas, and the cooling gas is the other of a cathode gas and an anode gas. A dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis,
A dehumidifier is provided in which a dehumidifier for dehumidifying the gas to be treated is stored in a container body and used by switching between a dehumidification step and a regeneration step.
A dehumidifying mechanism, wherein a hollow portion in which a dehumidifying agent is not formed is formed in a lower portion of the container body. A dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated using electrolysis,
A dehumidifier is provided in which a dehumidifier for dehumidifying the gas to be treated is stored in a container body and used by switching between a dehumidification step and a regeneration step.
A dehumidifying mechanism, wherein the container body is supported by a measuring device. A dehumidifying mechanism for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated using electrolysis,
In the preceding stage of the dehumidifier, a separation tank for separating the gas to be treated and water, and a gas cooler for cooling the gas to be treated separated in the separation tank,
A dehumidifying mechanism, wherein the water condensed by the gas cooler naturally flows down to the separation tank. A dehumidifying method for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis,
A dehumidifying step of dehumidifying one of the gases to be treated with a dehumidifying agent,
A regeneration step of heating and regenerating the dehumidifier,
A dehumidifying method, wherein the heated dehumidifying agent is indirectly cooled by the other gas to be treated in the regeneration step. A dehumidifying method for dehumidifying a gas to be treated of a cathode gas and / or an anode gas generated by using electrolysis,
A dehumidifying step of dehumidifying the gas to be treated with a dehumidifying agent,
A regeneration step of heating and regenerating the dehumidifier,
A dehumidification method, wherein the dehumidification step and the regeneration step are switched based on the weight of the dehumidifier measured in the dehumidification step and / or the regeneration step.

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