JP3181687B2 - Hydrogen recovery / purification apparatus and operation method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen recovery and purification apparatus and a method for operating the same.

[0002]

2. Description of the Related Art A conventional hydrogen recovery and purification apparatus is disclosed, for example, in Japanese Patent Laid-Open No. 3-271101. This hydrogen recovery and purification device connects a hydrogen utilization device and a hydrogen recovery container having a built-in hydrogen storage alloy and having a heating device and a cooling device attached thereto through an absorption gas line having a first pressure control valve, A discharge gas line having the following structure is connected to the hydrogen recovery container.

[0003] However, in this conventional hydrogen recovery and purification apparatus, when hydrogen gas from the hydrogen utilization apparatus is occluded in the hydrogen storage alloy in the hydrogen recovery vessel cooled by the cooling apparatus, the hydrogen utilization inside the hydrogen utilization apparatus is not performed. However, there is a technical problem that the toxic gas mixed for some reason is occluded together with the hydrogen gas, and the toxic gas is accumulated in the hydrogen storage alloy, so that the capability of hydrogen recovery and purification gradually decreases.
As such a poisoning gas, oxygen and other atmospheric components are known.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional technical problems, and the structure of the hydrogen recovery and purification apparatus is such that sealing members are provided at both ends of an outer cylinder, respectively. A hydrogen recovery container having a heat medium flow path partitioned by a partition member spanned between a pair of sealing members, and a hydrogen recovery container that is accommodated inside the hydrogen recovery container and outside the heat medium flow path, and stores hydrogen therein. A hydrogen storage alloy that stores hydrogen as a compound, an absorption gas line that introduces hydrogen into the hydrogen recovery container through a first valve, a release gas line that is connected to the hydrogen recovery container, and that interposes a second valve, A gas line for poisoning gas release with a third valve interposed therebetween, wherein the hydrogen storage alloy is heated to a temperature at which hydrogen is released by a heat medium passing from one end opening to the other end opening of the heat medium flow path. Configure a first heating device for heating A cooling device that cools the hydrogen-absorbing alloy to a temperature at which hydrogen is absorbed by the heat medium passing through the heat medium flow path is configured, and is insertable into and removable from the heat medium flow path. The toxic gas adhering to the hydrogen storage alloy is released from the toxic gas releasing gas line by a temperature lower than the heating temperature of the first heating device by 40.
A second heating device for heating the hydrogen storage alloy to a high temperature of not less than ° C is attached. Then, a vacuum pump for reducing the pressure inside the hydrogen recovery container can be connected to the toxic gas release gas line. Further, the configuration of the operation method of the hydrogen recovery / purification apparatus is such that a sealing member is provided at each end of the outer cylinder, and a hydrogen recovery channel having a heat medium flow path partitioned by a partition member provided between the pair of sealing members. A container, a hydrogen storage alloy contained in the hydrogen recovery container outside the heat medium flow path, and storing hydrogen as a hydride, and introducing hydrogen into the hydrogen recovery container through a first valve. One end opening of the heat medium flow path, comprising: a gas line for absorption, a gas line for discharge connected to the hydrogen recovery container and interposed with a second valve, and a gas line for discharge of toxic gas interposed with a third valve. A first heating device is configured to heat the hydrogen storage alloy to a temperature at which hydrogen is released by a heat medium passing through the heat medium toward the other end opening, and hydrogen is passed through the heat medium passage through the heat medium passage. Hydrogen storage alloy up to the storage temperature Using a hydrogen recovery / purification device that constitutes a cooling device for cooling, inserting a second heating device into the heat medium flow path, and releasing the toxic gas by the second heating device using the first heating device. The hydrogen storage alloy is heated to a temperature of 40 ° C. or more higher than the heating temperature by the above method, and the released poisonous gas is caused to flow out of the poisonous gas releasing gas line to the outside.

[0005]

The cooling device cools the hydrogen storage alloy in the hydrogen recovery container. For example, hydrogen gas from a hydrogen utilization device is introduced from an absorption gas line, and the hydrogen gas is supplied to the hydrogen storage alloy in the hydrogen recovery container. In the occluded state, the hydrogen storage alloy in the hydrogen recovery container is heated at a relatively low temperature by the first heating device. As a result, hydrogen gas is released from the hydrogen storage alloy in the hydrogen recovery container in which hydrogen has been stored, and the released high-purity hydrogen gas flows out through the release gas line.
When storing hydrogen gas, the first valve is opened and both the second and third valves are closed. When releasing hydrogen gas, the first and third valves are both closed, and the second valve is opened.

When the poisoning gas for the hydrogen storage alloy is mixed into the hydrogen utilization device for some reason and is deposited and accumulated on the hydrogen storage alloy for a long time to gradually reduce the storage capacity, the second heating device is used. Activate That is, after the hydrogen gas is released from the hydrogen storage alloy, the second heating device is inserted into the heat medium flow path, the second heating device is operated, and the hydrogen storage alloy is heated at 40 ° C. higher than the heating temperature of the first heating device. The heating is performed to the above high temperature, and the temperature state is maintained for a predetermined time. Thereby, the toxic gas adhering to the hydrogen storage alloy is gradually released. The released poisonous gas is released outside through a poisoning gas releasing gas line. When releasing the poisonous gas, the first and second
Close the valves together and open the third valve. that time,
By driving the vacuum pump, the toxic gas can be forcibly discharged to the outside. Thus, the hydrogen storage alloy in the hydrogen recovery container is activated, and the hydrogen storage capacity is regenerated.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show one embodiment of a hydrogen recovery and purification apparatus. In the figure, reference numeral 1 denotes a hydrogen recovery container that stores a hydrogen storage alloy A (metal hydride). The hydrogen recovery container 1 has sealing members 1b and 1c at both ends of an outer cylinder 1a.
(End plate) and a plurality of partition members 1d spanning between the pair of sealing members 1b and 1c.
Is partitioned. The heat medium flow path 9 has one end opening 9a and the other end opening 9b that open to the respective sealing members 1b and 1c.
Having. The hydrogen storage alloy A that stores hydrogen as hydride is accommodated in a space defined by the outer cylinder 1a, the sealing members 1b and 1c, and the partition members 1d.

An inlet cover 17 is detachably attached to one sealing member 1b of the hydrogen recovery container 1 by a bolt (not shown). The inlet cover 17 is connected via a pipe 19 having an open / close valve 18. It is connected to the heat medium supply device 20. An outlet lid 21 is detachably attached to the other sealing member 1c by a bolt (not shown). The outlet lid 21 is connected to the above-described heat medium supply device 20 by a pipe 23 having an open / close valve 22. It is connected. Reference numeral 2 denotes a temperature sensor for detecting the temperature of the hydrogen storage alloy A in the hydrogen recovery container 1.

The heat medium from the heat medium supply device 20 passes through the pipe 19, the on-off valve 18, and the inlet cover 17, passes through the heat medium flow path 9 from one end opening 9 a, and receives the hydrogen in the hydrogen recovery container 1. The storage alloy A is heated or cooled to open the other end 9
b, the outlet lid 21, the open / close valve 22, and the pipe 2
3 and is returned to the heat medium supply device 20. The first heating device 7a or the cooling device 8 for heating or cooling the hydrogen storage alloy A in the hydrogen recovery container 1 by adjusting the temperature of the heat medium.
Function as The cooling device 8 functions by supplying a heat medium, for example, cold water, from the heat medium supply device 20 to the heat medium passage 9, and cools the hydrogen storage alloy A to a temperature at which hydrogen is stored by the cooling device 8. In addition, the first heating device 7a
The first heating device 7a functions by supplying a heat medium, for example, hot water or steam, from the heat medium supply device 20 to the heat medium flow path 9.
Accordingly, the hydrogen storage alloy A is heated at a relatively low temperature to a temperature at which hydrogen is released.

In this embodiment, the outer cylinder 1
a has a large-diameter cylindrical shape, a plurality of partition members 1d have a small-diameter cylindrical shape, and constitutes a shell-and-tube heat exchanger. Alternatively, a plate-type heat exchanger that partitions the heat medium flow path 9 with a pair of plate-shaped partition members may be configured.

Next, on one side of the hydrogen recovery container 1, an absorption gas line 3 with a first valve 4 having an opening / closing function interposed is provided.
Are connected at one end. The other end of the absorption gas line 3 is connected to a hydrogen utilization device 10 such as a hydrogen-cooled generator, a semiconductor manufacturing facility, or the like. However, the hydrogen utilization device 10 here may be any device that releases hydrogen gas used for recovery and purification, and includes a hydrogen generation device such as an ammonia decomposition device.

The other end of the discharge gas line 6 is connected to the other side of the hydrogen recovery container 1, and the discharge gas line 6 is provided with a second valve 5 having an opening / closing function. The hydrogen gas is introduced from the absorption gas line 3, recovered and purified by the hydrogen storage alloy A in the hydrogen recovery container 1, and flows out from the release gas line 6. A hydrogen utilization device 10 is normally connected to the other end of the release gas line 6 so that the hydrogen gas recovered and purified in the hydrogen recovery container 1 is circulated and used. Then, the gas line 11 for releasing toxic gas is connected to the hydrogen recovery container 1 via the third valve 15, the condenser 13 and the vacuum pump 12. The vacuum pump 12 has a function of opening the third valve 15, driving the first valve 4 and the second valve 5 in a closed state, and depressurizing the inside of the hydrogen recovery container 1.

Further, the hydrogen recovery container 1 is provided with a second heating device 7b for heating the hydrogen storage alloy A at a relatively high temperature. The second heating device 7b is composed of, for example, an electric heater and can be inserted into and removed from the heat medium flow path 9. In the inserted state, the second heating device 7b is fixed to one of the sealing members 1b by a bolt (not shown) to store hydrogen. The hydrogen storage alloy A is heated to a temperature higher than the heating temperature of the first heating device 7a by 40 ° C. or more so as to release the poisonous gas such as the atmosphere from the alloy A.

The hydrogen storage alloy A reacts with hydrogen gas and reversibly stores or releases hydrogen gas. This reaction is based on hydrogen equilibrium pressure-temperature characteristics (PT characteristics) in the plateau region. From the temperature condition at equilibrium pressure,
When cooled to a low temperature, hydrogen gas is absorbed, and when heated to a high temperature, hydrogen gas is released. Thus, the normal first heating device 7a in the conventional hydrogen recovery / purification device heats the hydrogen storage alloy A to a maximum of about 150 to 170 ° C. to release hydrogen gas. 7b is 20
It is sufficient to have the ability to heat the hydrogen storage alloy A to 0 ° C. or higher. Reference numeral 26 denotes a power / control device that controls the second heating device 7b based on a detection signal from the temperature sensor 2.

Next, the operation of the above embodiment will be described. With the second heating device 7b pulled out, and with the inlet cover 17 and the outlet cover 21 attached to the hydrogen recovery container 1, the cooling device 8 cools the hydrogen storage alloy A in the hydrogen recovery container 1, and The first valve 4 is opened with the third valves 5 and 15 closed, and hydrogen gas from the hydrogen utilization device 10 is introduced from the gas line 3 for absorption, and the hydrogen recovery container 1
To be supplied. As a result, hydrogen gas begins to be stored in the hydrogen storage alloy A of the hydrogen recovery container 1. After the storage of the hydrogen gas by the hydrogen storage alloy A is completed, the hydrogen storage alloy A in the hydrogen recovery container 1 is heated at a relatively low temperature by the first heating device 7a, and the first valve 4 is shut off. The second valve 5 is opened. Thereby, hydrogen gas is released from the hydrogen storage alloy A in the hydrogen recovery container 1 in which hydrogen has been stored,
The released high-purity hydrogen gas flows out through the release gas line 6.

When the recovery and purification of hydrogen gas are repeatedly performed in this manner, the poisoning gas for the hydrogen storage alloy A is mixed into the hydrogen utilization device 10 for some reason, and the hydrogen storage alloy A is used for a long time. A is accumulated on A and gradually reduces the occlusion capacity. FIG. 3 shows the relationship between the hydrogen storage capacity of the hydrogen storage alloy A and the hydrogen storage time. In this figure, the curve a shows the characteristic after the activation treatment of the new hydrogen storage alloy A, the curve b shows the characteristic after poisoning for 2 hours, the curve c shows the characteristic after poisoning for 6 hours, and the curve d shows the characteristic after poisoning for 6 hours. After poisoning,
Shown respectively. These poisons were caused by hydrogen storage alloy A
Was given to the atmosphere for a predetermined time. It can be seen from the figure that the hydrogen storage capacity decreases as the poisoning time increases.

The second heating device 7b is operated when the hydrogen storage alloy A is poisoned and the hydrogen storage capacity is reduced. First,
After releasing the hydrogen gas from the hydrogen storage alloy A, the inlet cover 17 (or the outlet cover 21) is removed from the hydrogen recovery container 1, and the second heating device 7b is inserted into the heat medium flow path 9 to seal one side. It is fixed to the member 1b by a bolt (not shown).
Then, the first valve 4 and the second valve 5 are shut off and the third valve
The valve 15 is opened, the second heating device 7b is operated, and as shown in FIG.
It is shifted to the reproduction operation in ₁ ~t _2.

As is known from FIG. 2, the second heating device 7b is turned off during the normal operation, and the second heating device 7b is turned on during the regeneration operation. The hydrogen storage alloy A is heated to a high temperature T of 40 ° C. or higher than the heating temperature of the first heating device 7a.
₁ and the temperature is maintained for a predetermined time (t ₃
Be maintained only ~t _4), the toxic gas is released gradually adhered to the hydrogen-absorbing alloy A. The released poisonous gas flows out through the poisoning gas releasing gas line 11 to the outside. At that time, the vacuum pump 12 is driven to forcibly discharge the poisonous gas to the outside, and the condenser 13 is driven to condense the poisonous gas and discharge the poisonous gas to a high degree.

Thus, the hydrogen storage alloy A in the hydrogen recovery container 1 is activated, and the hydrogen storage capacity is regenerated to a state close to the curve a shown in FIG. FIG. 4 shows the hydrogen storage amount ratio (Q / Q
₀ ) and the temperature (° C.). Here, the hydrogen storage amount ratio is defined as the hydrogen storage amount Q of the hydrogen storage alloy A after the regeneration process from the poisoned state and the hydrogen storage amount Q of the non-poisoned and good-quality hydrogen storage alloy A that has been activated. _The temperature (° C.) is the predetermined temperature T ₁ shown in FIG.
₁ maintenance time (t ₃ ~t ₄₎ is about 1 hour. In FIG. 4, the f-curve shows the characteristics after poisoning for 2 hours, the g-curve shows the characteristics after poisoning for 4 hours, the h-curve shows the characteristics after poisoning for 6 hours, and the i-curve shows the characteristics after poisoning for 12 hours. , Respectively. The poisoning was performed by opening the hydrogen storage alloy A to the atmosphere for a predetermined time in the same manner as in the case described above.

As can be seen from the figure, it can be said that the recovery of the hydrogen storage amount ratio (Q / Q ₀ ) at a relatively low temperature of T ₁ = 200 ° C. or less is particularly good with the increase of the poisoning time. However, the hydrogen storage amount ratio (Q / Q ₀ ) at a relatively high temperature of about T ₁ = 400 ° C. or more recovers relatively well regardless of the length of the poisoning time.

[0021]

As will be understood from the above description,
According to the hydrogen recovery and purification apparatus of the present invention, the function of regenerating the poisoned hydrogen storage alloy is added, and the hydrogen storage alloy can be efficiently regenerated without removing the hydrogen storage alloy from the hydrogen recovery and purification apparatus. As a result, the life of the hydrogen storage alloy is extended,
As a result, the long-term use of the hydrogen recovery and purification device becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a hydrogen recovery and purification apparatus according to one embodiment of the present invention.

FIG. 2 is a diagram showing temperature-time characteristics of the second heating device.

FIG. 3 is a diagram showing a hydrogen storage capacity-hydrogen storage time characteristic.

FIG. 4 is a diagram showing a hydrogen storage amount ratio-temperature characteristic.

[Explanation of symbols]

1: hydrogen recovery container, 1a: outer cylinder, 1b, 1c: sealing member, 1d: partition member, 2: temperature sensor, 3: absorption gas line, 4: first valve, 5: second valve, 6: Release gas line, 7a: first heating device, 7b: second heating device, 8: cooling device, 9: heat medium flow path, 9a: one end opening,
9b: Opening at the other end, 10: Hydrogen utilization device, 11: Gas line for releasing toxic gas, 12: Vacuum pump, 13: Condenser, 15: Third valve, 17: Inlet lid, 19, 23: Piping, 20 : Heat medium supply device, 21: outlet cover, A: hydrogen storage alloy.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-271101 (JP, A) JP-A-2-9701 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C01B 3/00-3/56 B01D 53/14

Claims (3)

(57) [Claims] 1. A sealing member is provided at each end of an outer cylinder,
A hydrogen recovery container having a heat medium flow path partitioned by a partition member spanned between a pair of sealing members, and a hydrogen recovery container that is accommodated inside the hydrogen recovery container and outside the heat medium flow path, and stores hydrogen therein. A hydrogen storage alloy that stores hydrogen as a compound, an absorption gas line that introduces hydrogen into the hydrogen recovery container through a first valve, a release gas line that is connected to the hydrogen recovery container, and that interposes a second valve, A gas line for poisoning gas release with a third valve interposed therebetween, wherein the hydrogen storage alloy is heated to a temperature at which hydrogen is released by a heat medium passing from one end opening to the other end opening of the heat medium flow path. A first heating device for heating is constituted, and the heat medium passing through the heat medium flow path is
A cooling device is configured to cool the hydrogen storage alloy to a temperature at which hydrogen is stored, and the device can be inserted into and removed from the heat medium flow path. A hydrogen recovery and purification apparatus, comprising a second heating device for heating the hydrogen storage alloy to a temperature higher than the heating temperature of the first heating device by 40 ° C. or more so as to release the gas from the gas line for gas release. 2. The hydrogen recovery and purification apparatus according to claim 1, wherein a vacuum pump for reducing the pressure in the hydrogen recovery container is connected to the gas line for releasing toxic gas. 3. Sealing members are provided at both ends of the outer cylinder, respectively.
A hydrogen recovery container having a heat medium flow path partitioned by a partition member spanned between a pair of sealing members, and a hydrogen recovery container that is accommodated inside the hydrogen recovery container and outside the heat medium flow path, and stores hydrogen therein. A hydrogen storage alloy that stores hydrogen as a compound, an absorption gas line that introduces hydrogen into the hydrogen recovery container through a first valve, a release gas line that is connected to the hydrogen recovery container, and that interposes a second valve, A gas line for poisoning gas release with a third valve interposed therebetween, wherein the hydrogen storage alloy is heated to a temperature at which hydrogen is released by a heat medium passing from one end opening to the other end opening of the heat medium flow path. A first heating device for heating is constituted, and the heat medium passing through the heat medium flow path is
Using a hydrogen recovery / purification device that constitutes a cooling device that cools the hydrogen storage alloy to a temperature at which hydrogen can be stored, a second heating device is inserted into the heat medium flow path, and poisoning is caused by the second heating device. Heating the hydrogen storage alloy to a temperature higher than the heating temperature of the first heating device by 40 ° C. or more so as to release the gas, and discharging the released toxic gas from the toxic gas release gas line to the outside. Characteristic method of operating a hydrogen recovery and purification device.