JPS6114101A - Hydrogen purification apparatus - Google Patents

Abstract

PURPOSE:To make the apparatus compact and to reduce the cost of operation by providing a specified refrigeration cycle using flon to a purification cylinder in the hydrogen purification apparatus wherein two purification cylinders packed with a hydrogen-occluding alloy are alternately changed over and used. CONSTITUTION:Compressed raw gas is forced into the firts purification cylinder 3 in the occlusion stage through a pipe 1 and a valve 2 to occlude selectively the hydrogen in the raw gas (the temp. of the cylinder 3 is elevated), and the remaining gaseous impurities are discharged through a valve 8 and a pipe 9. Meanwhile, the occluded purified hydrogen is taken out from the second purification cylinder 13 in the discharge stage through a pipe 15 (the temp. of the cylinder 13 is lowered). Simultaneously with the operation, flon consisting of a mixed phase of gas and liquid is sent to the cylinder 3 from a liquid flon storage 4 through an expansion valve 5 to cool the cylinder 3. Then the vaporized flon is compressed by a compressor 12 and heated, and sent to the cylinder 13 to heat the cylinder 13. The liquefied flon is cooled by a supercooler 20 approximately to ordinary temp., and refluxed to the liquid flon storage 4. The operations are repeated while changing over the roles of the purification cylindrs 3 and 13 by the operation of valves.

Description

DETAILED DESCRIPTION OF THE INVENTION The technical field of the invention relates to an apparatus for purifying hydrogen gas from hydrogen-containing gas using a hydrogen storage alloy.

How to purify hydrogen using hydrogen storage alloys.

When a woodcutter's alloy takes advantage of its ability to absorb hydrogen, a hydrogen-absorbing alloy is filled in a container, and hydrogen gas containing impure gas is introduced into the container.

Only hydrogen gas is occluded in the alloy with heat generation, leaving behind impure gas. After releasing this impure gas to the outside of the container, if one alloy is heated, hydrogen absorbing gas is released from the alloy, and highly pure hydrogen is obtained. In this process, when hydrogen is absorbed, it generates heat, so it is cooled with cooling water to prevent the temperature from rising.On the other hand, when it is released, it absorbs heat, so it is heated with hot water to keep the temperature constant. need to be kept.

In order to operate this process continuously and produce high-purity hydrogen industrially, two or more purification cylinders filled with hydrogen storage alloy are installed, and hot water and cooling water are used as heating and cooling sources. Prepare and alternately switch the refining cylinder between the hydrogen storage process and the hydrogen release process.

Cooling water is selectively supplied to the purification cylinder in the hydrogen storage process, and hot water is supplied to the f# purification cylinder in the hydrogen release process.

However, in this method, hot water and cooling water are used for heating and cooling, and these sensible heats are used as the heat source.
The disadvantages are that the device becomes larger and consumes more energy.

However, there were limits to cooling with cooling water, and a major drawback was that the storage temperature could not be kept low enough, which forced the storage pressure to be high.

Purpose of the Invention The present invention was made in view of the above circumstances, and it is an object of the present invention to provide a hydrogen M manufacturing device using a hydrogen storage alloy that can reduce energy costs and make the device more compact. be.

Structure of the Invention The hydrogen purification apparatus of the present invention comprises two or more refining cylinders filled with a hydrogen storage alloy, the refining cylinder in the hydrogen storage process serving as an evaporator, and the refining cylinder in the hydrogen releasing process serving as a condenser. It is equipped with a refrigeration cycle.

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Specific structure of the invention and its operation The unexploded 8A will be explained in detail below with reference to one drawing.

The drawing shows an example of the hydrogen i/'ItIJ1 device of the present invention.

Hydrogen gas containing impurity gas is used as raw material gas at 2 to several L O
It is pressurized to about kg/cm and is sent from pipe 1 through valve 2 to first production cylinder 3 which is in the hydrogen storage process. The first cylindrical tube 3 contains a LaNi-based alloy, an F
It is filled with a hydrogen-absorbing metal coating such as an eTi-based alloy that has a high equilibrium hydrogen pressure near room temperature, and has a structure that allows heat exchange. Hydrogen in the raw material gas introduced into the first refining cylinder 3 is selectively occluded by the hydrogen storage alloy, and impure gas remains in the space inside the cylinder. Since this is an exothermic reaction or absorption of hydrogen into the hydrogen storage alloy, the temperature of the hydrogen storage alloy and the No. TN 1llI3 rises in this hydrogen storage step. When this temperature rises, the horizontal hydrogen pressure increases and the elementary storage rate decreases, so it is necessary to cool it. Therefore,
Freon lightning passes from the Freon liquid reservoir 4 through the expansion valve 5 and becomes a gas-liquid mixed phase state6. The fluorocarbons sent to the XIS cylinder 3 through the valve 7 and then cooled are gas-liquid mixed phase, so the latent heat of vaporization can be used for cooling, and the fluorocarbons have a high A small amount is sufficient.

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 8 is opened, and the impure gas is removed. Derived from the first precision tube 3.

The pipe 9 is also discharged, and the valve 7 is closed to stop the supply of fluorocarbon to the first tube-making cylinder 3. The fluorocarbon heated and vaporized in the first production tube 3 is transferred to the tube 10. Valve 11? : Then sent to the freon compressor 12.

On the other hand, the second refining cylinder 13 having the same structure as the first refining cylinder 3 is
At this time, it is in the hydrogen release process. Ding nawachi.

The hydrogen storage alloy filled as described above in the previous process stores water and impure gas is discharged.
From the refining cylinder L3, a water cable made of treetops released from the hydrogen storage alloy is connected to the valve 14. It is led out through tube 15. Since this release of hydrogen from the hydrogen storage alloy is an endothermic reaction, the temperature inside the second refiner tube 13 decreases. When the temperature inside the cylinder decreases, the hydrogen release rate and hydrogen release pressure decrease, so it is necessary to heat the cylinder.Therefore, the first production cylinder 3 is also sent to the freon compressor t2, where the temperature and pressure are increased. Condition M
Fluorocarbon pipe 16. After valve 17? Send it to the A2 refining cylinder. The vaporized fluorocarbon gas introduced into the second tree-making cylinder [3]
The hydrogen-absorbing alloy that is releasing hydrogen is heated, and at the same time, it is cooled and liquefied. Liquefied Freon is Bensho 8. It passes through a pipe 19, is cooled to approximately room temperature in an air-cooled or water-cooled subcooler 20, and is then stored in a fluorocarbon reservoir 4. Second
70/ introduced into the crack tube 13 generates condensation heat.

Excellent for heating young fruits, requiring only a small amount of fluorocarbons. Once hydrogen release has stopped, stop supplying vaporized fluorocarbons.

The second refining column 13 will enter the next hydrogen storage step.

Hereinafter, these two steps will be explained as follows.
Hydrogen can be continuously purified by repeating the process with and .

In such hydrogen purification equipment, high-temperature gaseous chlorofluorocarbons are introduced into the second purification column [3] during the water bulk discharge process that requires heating, and are heated and liquefied, and cooling is required at the same time. The first semi-fiber cylinder 3 in the hydrogen storage process
Freon in a gas-liquid mixed phase state is introduced into the tank to cool it and vaporize it, and the M-made cylinder in the hydrogen release process is used as a compressor.

Since we have formed a fluorocarbon refrigeration cycle in which the refining cylinder in the hydrogen storage process is used as an evaporator, the heat generated from, for example, the first refining cylinder 3 in the hydrogen storage process is transferred to the second refining cylinder L in the hydrogen desorption process.
It can now be used for heat absorption in step 3, and the refining tube [heating in step 3,
It becomes possible to reduce energy costs required for cooling. In addition, since easily condensable fluorocarbons are used, latent heat can be used for heating and cooling, and only a small amount of fluorocarbons need to be circulated to allow heating and cooling of young fruits. It is easy to keep the temperature distribution within t3 uniform, the operation is easy, and the equipment can be made compact. In addition, since the refining column in the hydrogen storage process can be cooled to a sufficiently low temperature, the hydrogen storage pressure can be lowered, and the compression power can be reduced by reducing the compression pressure of the raw gas.

Next, the economic efficiency of the N-made apparatus of the present invention and a conventional refining apparatus will be compared.

LaNi based alloy used as hydrogen storage alloy, 10kg7
100 Nm3/hr of hydrogen 'a [
In the case of cracking, the heating energy for hydrogen release is theoretically 35
000Kca 1/hr required. If this were to be covered by hot water using a conventional electric heater, 40Kw of electric power would be required, and electric power would also be required to operate the hot water circulation pump. On the other hand, the device of the present invention requires only 13 to L5 Kw of power as the Freon compressor 12 (7) jb power, and the power cost is less than half.

In addition, chlorinated methane (methyl chloride) other than the front
A heating medium such as or ammonia can also be used.

As described in detail, the hydrogen purification apparatus of the present invention is an apparatus that alternately operates two or more refining cylinders filled with a hydrogen storage alloy to perform a hydrogen storage process and a hydrogen release process. A Teikoku cycle with an InIIn upper evaporator and an f# cracked cylinder condenser in the hydrogen release process is installed, so the heat generated by the refining cylinder in the hydrogen absorption process is transferred to the hydrogen release process. Semen #! 1. Can be used to heat cylinders,
The energy cost required for heating and cooling M tubes can be greatly reduced.

In addition, since the I-made cylinder in the hydrogen storage process can be cooled to a sufficiently low temperature, the hydrogen storage alloy can be lowered to a lower temperature, and the power cost for compressing raw gas can also be reduced. This has the advantage that the equipment for this process can be made smaller and it is easier to operate.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an example of the hydrogen purification apparatus of the present invention. 3... First treetop tube, 4... Freon liquid reservoir, 5... Expansion valve, 12... Freon compressor, [3... Second
fttR tube, 20... supercooler.

Claims (1)

[Scope of Claims] An apparatus that purifies hydrogen from a hydrogen-containing gas by having two or more refining cylinders filled with a hydrogen storage alloy and alternately switching these refining cylinders to a hydrogen storage process and a hydrogen release process, A hydrogen purification device characterized by having a refrigeration cycle in which a purification column in a hydrogen storage process is used as an evaporator and a purification column in a hydrogen release process is used as a condenser.