JPS62123001A - Method for purifying hydrogen - Google Patents

Abstract

PURPOSE:To eliminate cooling and heating from the outside of system, to reduce purification cost and to simplify and miniaturize a device, by using heat generation in a purifying column in a hydrogen occlusion process for heat absorption in a purifying column in a hydrogen release process by transfer of a heating medium. CONSTITUTION:A hydrogen in a raw material gas is occluded in a hydrogen occlusion alloy 4 by a first purifying column 3 in a hydrogen occlusion process. Since hydrogen occlusion rate is dropped when temperature is raised by heat generation in the opera tion, a heating medium in a heat exchange pipe 5 for the heating medium is heated and evaporated by the heat generation to prevent rise in temperature. Introduction of the raw material gas 1 is stopped when the hydrogen occlusion alloy 4 is saturated and an impure gas is exhausted from a pipe 7. On the other hand, a second purifying column 11 is in a hydrogen release process and purified hydrogen released from the hydrogen occlusion alloy 4 is sent from a pipe 13. Since the release reaction is an endothermic reaction, the heating medium vaporized in the previous process is sent to a heat exchange pipe 14 for a heat medium of the second column 11 to prevent reduction in hydrogen release rate. When these processes are finished, the first column 3 is changed to the hydrogen release process and the second column 11 to the hydrogen occlusion process, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for f# purifying hydrogen gas from a hydrogen-containing gas using a hydrogen storage alloy.

[Prior art and its problems]

The method of splitting hydrogen using a hydrogen storage alloy takes advantage of the property of certain metal alloys to absorb hydrogen well. When a hydrogen storage alloy is filled in a container and hydrogen gas rich in impure gas is introduced into the container, only the hydrogen gas is absorbed by the alloy with heat generation, and the impure gas becomes 13iI. After releasing this impure gas to the outside of the container, if the alloy is heated, water-absorbing gas is released from the alloy, and high purity hydrogen can be obtained. In this process, when hydrogen is absorbed and formed, it generates heat, so it must be cooled with cooling water to prevent temperature fluctuations.On the other hand, when hydrogen is released, it absorbs heat, so it must be heated with hot water, etc. It is necessary to keep it constant.

In order to operate this process continuously to produce interstitial hydrogen on an industrial scale (1c>1), two or more refining cylinders filled with hydrogen storage alloy must be installed, and hot water and hot water can be used as heating and cooling sources. Prepare cooling water, switch the treetop HR alternately between the hydrogen absorption process and the hydrogen release process, and switch and supply cooling water to the purification cylinder in the hydrogen storage process and hot water to the purification cylinder in the hydrogen release process. I have to.

However, in this method, hot water and cooling water are used for heating and cooling, and these are used as sensible heat sources, which has the drawback of increasing the size of the device and increasing energy consumption.

(Means for solving the rl, i-1 vanishing point) Therefore, in this invention, a 1゛amylated heat medium is introduced into the refining cylinder in the hydrogen storage process, and the heat generated in the fi-fi fission cylinder is is absorbed as the latent heat of vaporization of the heating medium to vaporize the heating medium, and this vaporized heating medium is introduced into the refining cylinder in the hydrogen release process, the alloy in this refining cylinder is heated, the heating medium is condensed and liquefied, and this By sending the liquefied heat medium back to the refining column in the hydrogen storage process, external heating and cooling are no longer necessary, reducing energy costs and simplifying and downsizing the equipment.

Hereinafter, the #I manufacturing method of the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an example of a purification apparatus 4 suitable for carrying out the hydrogen purification method of the present invention.

Hydrogen gas containing impurity gas is used as raw material gas.
The first ftN is pressurized to a certain degree and is in the hydrogen storage process from pipe 1 through valve 2! l! ! ! It is introduced into the tube 3.

The first coffin tube 3 contains L a Ni alloy, F
It is filled with a hydrogen storage alloy 4 having a high equilibrium hydrogen pressure near room temperature, such as an eTi-based alloy, and has a built-in heat exchange pipe 5 for heat medium, so that heat exchange can be performed. Hydrogen in the raw material gas introduced into the first mill making cylinder 3 is selectively occluded in the hydrogen storage alloy 4, and impure gas remains in the space inside the cylinder. Since hydrogen storage into the hydrogen storage alloy 4 is an exothermic reaction, the temperature of the hydrogen storage alloy 4 and the first #1 IJ cylinder 3 rises in this hydrogen storage step. When this temperature increases, the hydrogen equilibrium pressure increases and the hydrogen absorption ML capacity decreases, so it is necessary to cool it. For this purpose, a liquid heat medium, such as CCb Fy C
Ce 2 Fz e CCg F37. The generated heat heats and evaporates the heating medium, thereby preventing a rise in temperature. At this time, since the latent heat of vaporization of the heating medium can be used, the cooling effect is high (and the number of heating medium tubes may be small).

In this way, when hydrogen storage progresses and the hydrogen storage alloy becomes saturated, the introduction of the raw material gas is stopped, the valve 6 is opened, and the impure gas is led out and discharged from the pipe 7 to the outside of the system. The vaporized heat medium passes through a heat medium valve 8, a heat medium pipe 9, and a heat medium valve 10, and then enters the second heat medium.
It is sent to the refining column 11.

On the other hand, the second refined slate 11, which has a similar structure to the first cypress slate 3, is in the hydrogen release process at this time. That is, as described above in the previous process, the filled hydrogen storage alloy 4 stores hydrogen and the second treetop cylinder 11ρ) is in a state where impurity gas is discharged.
In these cases, the loaded hydrogen released from the hydrogen storage alloy 4 is 12 square meters.
,'[,713. Hydrogen generation from this hydrogen storage alloy 4 is an endothermic reaction, so when the repulsion of the second cylindrical cylinder 11 decreases, the hydrogen release rate and hydrogen release pressure decrease, so it is inevitable that mytA will occur. Therefore, as this heating source, the heat exchange pipe 14 for the heat medium of the second treetop slate 11, which is the heat medium vaporized in the first treetop tube 3, as described in iIJ.
The heating medium that heated the inside of the cylinder 11 is cooled and liquefied.

In this way, the first refining cylinder 3 performs the hydrogen storage process, and the second N cylinder 11 performs the hydrogen release process. When these processes are completed, the 11fI cylinder 3 performs the hydrogen desorption process, and the second refining cylinder 11 performs the hydrogen desorption process. The process is switched to the occlusion process, and the raw material gas is introduced from the pipe 1 through the valve 15 into the second production cylinder 11, and the impure gas is discharged from the pipe 17P16. Further, purified hydrogen gas is led out from the first grist cylinder 3 via a valve 17 and a pipe 13. At this time, the hypothermia that was liquefied in the second refining cylinder 11 in the previous step is heated by the heat produced by the second top-forming cylinder 11 entering the hydrogen storage process, and is vaporized. The vaporized heat medium is transferred to the heat medium valve 10. It is introduced into the first refining cylinder 3 through the heat medium pipe 9 and the heat medium valve 8, where it heats the first refining cylinder 3 which is in the hydrogen release process, and liquefies itself.

As described above, hydrogen can be continuously -i'J IJ by alternately switching the hydrogen storage process and the hydrogen release process in the first purification cylinder 3 and the second purification cylinder 11. The transfer of the heat medium between the first top-forming cylinder 3 and the second #tff cylinder 11 occurs naturally due to the difference in vapor pressure due to the temperature difference between the refining stations. In addition, the heating medium used here has a boiling point between the storage temperature during hydrogen storage and the release temperature during hydrogen release, and has an fQ degree in between, which facilitates the movement of the heating medium. It is also desirable to do so.

[For production]

In this type of hydrogen purification method, the heat generated by the refining column during the hydrogen storage process is used to absorb heat from the refining column during the hydrogen release process through the action of a heating medium, eliminating the need for heating and cooling from outside the system. In addition, since the latent heat of vaporization and liquefaction of the heating medium is utilized, the heat capacity can be increased, which suppresses the heat transfer effect and reduces the hydrogen In addition, since only one heating medium system is required, equipment can be simplified, equipment costs are low, and operation is easy and there is little risk of failure.

FIG. 2 shows another example of the apparatus for carrying out the hydrogen production method of the present invention, and the same components as those shown in FIG. omitted. In this example, IC, Jl, etc. are used when the equipment becomes large and many heating mediums are required.

When the first clearing cylinder 3 is in the hydrogen storage process and the second yuri cylinder 11 is in the hydrogen releasing process, the heat medium is sent out from the heat medium tank 18 by the pump 19, passes through the pipe 20% valve 21, and is transferred to the first purification cylinder. 3 is sent to the heat exchange pipe 5 for heat medium.

The first Kozue-made strawberry 3 is cooled, and the vaporized heat medium is released from the valve 8;
It moves to the heat exchange pipe 14 for the heat medium of the second oval cylinder 11 via the heat medium pipe 9 and the valve 10, heats the second wooden cylinder 11 here, and liquefies itself, and the heat for the heat medium is transferred. Replacement vibrator 14 to valve 22
The heat medium is then collected in the heat medium tank 18. Next, when the first refining chamber 3 enters the hydrogen release process and the 21st cylinder 11 enters the hydrogen storage process, the heat medium is sent from the pump 19 to the #1 cylinder 11 via the blue 20 and valve 23. Further, it moves to the first tree-making cylinder 3, passes through the first tree-making cylinder 3 to the square 24, and then passes through the heating medium tube 18.
people.

In this case, is it a heating medium? : It will be stored outside the treetop refinery,
It is possible to reduce the volume occupied by the heat exchange pipe for the heat medium in the refining cylinder and increase the amount of hydrogen absorbing alloy violet in the refining cylinder.

Furthermore, since the heat medium supply layer can be arbitrarily adjusted by the pump 19, the hydrogen storage and release rate can be reduced to 1ijil '61J.

In addition, unmanned operation can be performed by using automatic valves for all the injection valves in the first station. In addition, any type can be used for the heating medium barrel pipe in the refining cylinder, such as the two-if type, the multi-¥11 type, and the great fin type. Also, depending on the type of hydrogen-sulfur absorbing alloy, storage pressure, release pressure, etc., the heating medium may be C', Hs Ce* Cr4 C1h tCCls
F, CC112F2. CHFz Ce, C3C
Various types such as ds F3v N)b can be used, and it is also possible to change the boiling point by applying pressure. moreover,
It is also possible to reduce the hydrogen release rate by suppressing the heating ly (self-water heater, V6 air heater, etc.) in the heat medium pipe 9, or by providing a cooling source such as a chiller to lower the hydrogen release rate.

〔Example〕

i'31 Using the equipment shown in Figure 31, the water storage alloy is
aN is k, heat medium toshite CCe5FC floor R-
11, boiling point 26.7°C, 1^tm) was used to carry out the hydrogen U production method of the present invention. The hydrogen suction pressure was 8 atm - the hydrogen discharge pressure was f, 5 atm. When hydrogen is absorbed at 8 atm, heat of 55°C is generated. On the other hand, 1.5a
When hydrogen is released at tm, it absorbs heat and is cooled to 15°C. Therefore, if a heating medium is sealed in the W part in the storage process, it will absorb heat and vaporize. The vaporized heat medium moves to the refining column in the discharge process, where it is cooled and liquefied.

In this embodiment, the heat generated during hydrogen storage can be used for the heat absorption during hydrogen release, and all heat from the outside is not required.In contrast, in the conventional system, approximately 2,907 liters of heat is required for the hydrogen storage process and the hydrogen release process. /Nrrjl-b is required, and if only heating during hydrogen storage is performed using an electric heater, approximately Q, 3kwh of power will be consumed.

〔Effect of the invention〕

As explained above, in 7 of the present invention, the uncoated coffin manufacturing method introduces a specific heating medium into the PR manufacturing process in the hydrogen storage process, vaporizes the heating medium with the heat generated in this refining cylinder, and generates heat from this vaporization. In order to introduce the medium into the refining cylinder in the hydrogen release process, heat the refining cylinder to form a cage for the heating medium, and then switch the refining cylinder to the hydrogen storage process and repeat the same process. No cooling is required and energy costs are eliminated.

@ Since it utilizes the latent heat of vaporization and latent heat of liquefaction of the heating medium, it has a large heat capacity (improves the heat transfer effect and shortens the storage and release times.

θ Since only one heating medium system is required, the entire device can be simplified, the equipment cost is low, the pump rotation is simple, and maintenance is easy.

It has the following advantages.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are both schematic configuration diagrams showing an example of an apparatus used in the hydrogen purification method of the present invention.

Claims (1)

[Claims] In a method of purifying hydrogen from a hydrogen-containing gas by providing a plurality of purification cylinders filled with a hydrogen storage alloy and having built-in heat exchange pipes, and switching these purification cylinders alternately to a hydrogen storage process and a hydrogen release process, A liquefied heating medium is introduced into the refining cylinder in the hydrogen storage process between the heat exchange pipes of each refining cylinder, and the heat generated in this refining cylinder is absorbed as latent heat of vaporization of the heating medium to vaporize the heating medium. The method is characterized in that a vaporized heat medium is introduced into a refining cylinder in a hydrogen release process, the refining cylinder is heated, the heat medium is condensed and liquefied, and this liquefied heat medium is sent to a refining cylinder in a hydrogen storage process. hydrogen purification method.