JPS5978907A - Refining method of gaseous hydrogen - Google Patents

Abstract

PURPOSE:To refine inexpensively gaseous hydrogen to high purity with a simple installation by joining at least a set of gaseous hydrogen storage tanks contg. a hydrogen occluding alloy in series, connecting heat-exchangeably the same to each other and occluding and releasing successively gaseous hydrogen. CONSTITUTION:A gaseous hydrogen storage tank 4 in a front stage contg. a hydrogen occluding alloy 5 such as a Ti-Mn alloy or the like having a high equil. hydrogen pressure and a gaseous hydrogen storage tank 7 in a rear stage contg. a hydrogen occluding alloy 8 such as an Mn-Ni alloy having the equil. hydrogen pressure lower than said pressure are joined in series by means of a connecting pipe 10, and both storage tanks 4, 7 are connected heat exchangeably to each other by means of a heat exchanging pipe 19 through a circulation pump 18. The high pressure gaseous hydrogen in a bomb 1 is introduced through a gaseous hydrogen supply pipe 3 into the tank 4 where the gaseous hydrogen is occluded in the alloy in the above-mentioned constitution; at the same time, the hydrogen occluded in the tank 7 is released from a refined gas supply pipe 14. The release in the tank 4 and the occlusion in the tank 7 are accomplished in the succeeding stage. The heat generated by the occlusion is utilized by a heat exchange for the absorption of the heat required for the release.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying hydrogen gas to a high purity using a hydrogen storage alloy exclusively for titanium-manganese alloys.

Is it ambient air gas for the semiconductor industry, float process plate glass manufacturing, or metal heat treatment? The ambient gas may require, for example, 1,000% high purity hydrogen gas.

By the way, adsorption and diffusion methods have traditionally been used to purify hydrogen gas, but both have the disadvantage of expensive equipment, and the adsorption method requires an ultra-low temperature source such as liquid nitrogen, which increases running costs. There were drawbacks such as.

On the other hand, hydrogen storage alloys such as Ti-Mn base metals absorb only hydrogen in hydrogen gas containing impurities and release only hydrogen, so a method for purifying hydrogen gas using this principle has already been proposed in JP-A-31 ．． -Disclosed by Zazani No. 03. In this method, a set of containers containing a hydrogen storage alloy are connected in parallel, and the hydrogen gas to be purified is stored in one container, and at the same time, the hydrogen gas stored in the alloy is released from the other container as purified hydrogen. Furthermore, by connecting the same containers to each other through a heat exchanger so that they can exchange heat with each other, the heat generated during hydrogen storage in one container can be used as the heat required for releasing hydrogen in the other container, thereby eliminating the need for a heating/cooling source. The aim is to obtain purified hydrogen gas continuously at low cost.
In this case, a set of containers containing hydrogen storage alloys were connected in parallel, and the hydrogen gas to be purified only passed through one of the sets of containers once, so depending on the purpose of use, there was sufficient There was a drawback that purification purity could not be obtained.

Therefore, in the present invention, a set of containers (hydrogen gas storage tanks) are connected in series to the front and rear stages through connecting pipes, and both of the water gas storage tanks are connected to be able to exchange heat with each other, thereby purifying the hydrogen gas storage tank into the hydrogen gas storage tank at the front stage. A process of storing hydrogen gas and simultaneously releasing hydrogen gas as purified gas from a subsequent hydrogen gas storage tank, and transferring the hydrogen gas once stored in the previous hydrogen gas storage tank to the subsequent hydrogen gas storage tank through the connecting pipe. This is a hydrogen gas purification method comprising a step of re-occlusion in a hydrogen gas storage tank, in which the hydrogen gas can be passed through a hydrogen gas storage tank at least once, and high purification capacity can be obtained even with small equipment.

The present invention will be specifically explained below with reference to the drawings. In the figure, 1 is a commercially available gas cylinder filled with compressed hydrogen of about 50% purity, and inside a cylindrical hydrogen gas storage tank 4 to which a hydrogen supply pipe 3 with a valve 2 at its opening is connected. contains a bulk Ti-Mn hydrogen storage alloy 5, and a filter tube 6 is disposed at the center of the interior. The filter tube 6 is a porous sintered alloy manufactured by sintering stainless steel powder, and one end thereof is
This hydrogen supply pipe 3 is connected. This is a hydrogen gas storage tank similar to that shown in Figure 7, but it contains a -NI or Fe-Ti hydrogen storage alloy 8, which has a lower equilibrium hydrogen pressure than the Ti-Mn system. 9 is the filter tube.

A connecting pipe 10 connects the hydrogen gas storage tank 4.1 to the ends of the filter tubes 6.9, and a valve U is interposed in the middle of the connecting pipe 10. The connecting pipe 10 is branched to the primary side of the valve H, and an exhaust pipe ν is connected thereto, and an exhaust valve 13 with a large opening is provided to this. 14 is the fin 1. of the hydrogen gas storage 117. A valve 15 is interposed in the purified gas supply pipe connected to the other end of the turbine 9. A branched exhaust pipe 16 is connected to the primary side of the valve 15, and, like the valve 13, an exhaust valve 17 that is open to the atmosphere is provided. Also, a heat exchange pipe 19 &t' equipped with a circulation pump 18, and both hydrogen gas storage tanks 4. It is arranged in a coil shape in γ, and the heat medium is caused to flow by the operation of the circulation pump 18! 11, both hydrogen gas storage tanks 4.7 are configured to be able to exchange heat with each other.

Now, when refining the hydrogen gas in the cylinder, first, the inside of the hydrogen supply pipe 3, the inside of the hydrogen gas storage tank 4.7, and the serial #10
Inside, the purified gas supply pipe 14 is replaced with hydrogen gas as pure as possible, and then valve 11 is closed and valve 2.
15 is opened, and valves 13 and 17 are of course closed. Therefore, the high pressure hydrogen gas in the cylinder 1 is transferred to the hydrogen supply pipe 3.
The hydrogen gas is guided through the hydrogen gas storage tank 4 and stored in the hydrogen storage alloy 6. That is, the hydrogen gas storage tank 4 contains cylinders 1 and 3.
09! (The high pressure above the station is applied and it reacts with the alloy 5 to produce hydride. This is an exothermic reaction, and the heat generated at that time is absorbed by the medium in the heat exchanger vibe 19 and circulated into the hydrogen gas storage tank.) 7. The hydrogen storage alloy 8 which has already stored enough hydrogen gas is placed in the hydrogen gas storage tank 7, and the valve 15 is now opened to reduce the pressure inside the tank, and the heat exchange vibrator 19 When heated by the thermal energy transferred from the hydrogen gas storage tank 7, the hydride is decomposed and hydrogen gas is released into the purified gas supply pipe 14.The hydrogen storage alloy 5 is saturated with hydrogen gas, and the hydrogen storage alloy 8 is heated. After most of the stored hydrogen gas is released,
Close valve 2.15. Then, the valve 13 is opened to discharge the impure gas remaining in the hydrogen gas storage tank 4 without being stored in the hydrogen storage alloy 5 into the atmosphere. After that, the pulp train is closed and the valve U is opened to transfer the hydrogen gas stored in the hydrogen storage alloy 6 through the connecting pipe 10 to the hydrogen storage alloy 8.
to be reabsorbed. At that time, the equilibrium hydrogen pressure of the hydrogen storage alloy 5 in the hydrogen gas storage tank 4 in the previous stage is about 30 atmospheres of Ti-M
n series, and the equilibrium hydrogen pressure of the hydrogen storage alloy 8 in the hydrogen gas storage tank 7 in the latter stage is about 10 sword pressures lower than that of the hydrogen storage alloy 5, so the hydrogen gas released from the hydrogen storage alloy 5 is 8 is well absorbed. In addition, the heat generated from the hydrogen storage alloy 8 at that time is absorbed by the heat medium in the heat exchanger vibe 19 and transferred to the hydrogen @ louse alloy 5, so the hydrogen storage alloy 8
The hydrogen gas release action of the hydrogen storage alloy 8 and the hydrogen gas storage action of the hydrogen storage alloy 8 are respectively promoted 8, and when the hydrogen storage alloy 8 reaches a saturated state with hydrogen gas, the hydrogen gas storage tank 7 is closed by closing the valve 11 and opening the valve 17. Impure gas remaining without being stored in the hydrogen storage alloy 8 is discharged into the atmosphere. Thereafter, the valve 17 is closed and the valve 15 is opened to release the pure hydrogen gas stored in the hydrogen storage alloy 8 into the purified gas supply pipe 14. At the same time, the valve 2 is opened to release the hydrogen gas in the cylinder l again into hydrogen gas. The hydrogen is introduced into a storage tank 4 and stored in a hydrogen storage alloy 5. Thereafter, in the same manner, the hydrogen gas once stored in the hydrogen gas storage tank 4 in the previous stage is transferred to the hydrogen gas storage tank 7 in the latter stage to be re-occluded, and the hydrogen gas to be purified is stored in the hydrogen gas storage tank 4 in the previous stage. At the same time, the process of releasing hydrogen gas as purified gas from the hydrogen gas storage tank in the latter stage is performed alternately, and during this period, the hydrogen gas storage tanks in the front and rear stages exchange heat with each other to achieve rc storage and release actions. It is. Incidentally, when a commercially available hydrogen gas having a purity of 1.5% was supplied from the hydrogen supply pipe 3 and purified, hydrogen gas of a purity of 1.5% was obtained in the purified gas supply pipe 14. If necessary, further purification can be achieved by connecting multiple stages of hydrogen gas storage tanks in series. Even in that case, if the hydrogen gas storage tanks in the front and rear stages are connected for heat exchange so that hydrogen gas can be stored and released at the same time, no other heat source or cooling source is required, and the drop in gas pressure can be avoided. For this purpose, a pressure boosting pump is placed in place.

As explained in the embodiments above, according to the hydrogen gas purification method of the present invention, hydrogen gas can be purified to a high purity with simple equipment using two sets of hydrogen gas storage tanks, and furthermore, no heat source is required due to heat exchange. Since the system can be operated at low running costs, it is advantageous.

[Brief explanation of the drawing]

The drawing is a schematic diagram of an apparatus manufactured by M, showing an embodiment of the present invention. 2...Valve, 3...Hydrogen supply pipe, 4...
Hydrogen scum storage tank, 5...Hydrogen storage alloy, 7...Hydrogen gas storage tank, 8...Hydrogen storage alloy, 10...Connecting pipe, 11...Valve, 12...・Emission! , 1
1...Halfke 14...Purified gas supply pipe, 15
... Valve, 16... Discharge pipe. 17... Valve, ]8-... Circulation pump, 19.
...Heat exchange pipe. Patent applicant: Daido Steel Co., Ltd.

Claims (1)

[Scope of Claims] 1. At least one set of hydrogen gas storage tanks containing a hydrogen storage alloy are connected in series in the front and rear stages by connecting pipes, and both hydrogen gas storage tanks are connected to each other so as to be able to exchange heat, and A step in which the hydrogen gas to be purified is stored in the hydrogen gas storage tank in the previous stage and at the same time, the hydrogen gas is released as purified gas from the hydrogen gas storage tank in the latter stage, and the hydrogen gas once stored in the hydrogen gas storage tank in the former stage is passed through the connecting pipe to the latter stage. A hydrogen gas purification method comprising the step of transferring the hydrogen gas to a hydrogen gas storage tank and re-occluding it. 2. The hydrogen gas purification method according to claim 1, wherein the hydrogen gas storage tank at the front stage contains a hydrogen storage alloy having a higher equilibrium hydrogen pressure than the hydrogen gas storage tank at the rear stage.