JPS5945901A - Method and apparatus for releasing hydrogen from hydrogen-occluding substance - Google Patents

Abstract

PURPOSE:To release hydrogen from a silicon-containing substance for the storage of hydrogen, by utilizing the chemical reaction of said substance with an aqueous solution of an alkali. CONSTITUTION:A silicon-containing substance for the storage of hydrogen (SiH2) is prepared by carrying out the glow discharge or sputtering of silane gas at about 0.1-10Torr, thereby depositing the powdery product to the cooled face. A slurry containing abut 30wt% of the slicon-containing substance is prepared in the tank 1, and separately, an aqueous solution of NaOH is prepared in the tank 2. The pumps 5 and 6 are operated to introduce the SiH2 slurry and the NaOH solution into the reactor 7 and contact the components with each other. The generated hydrogen gas is recovered through the vapor-liquid separator 9 and the desiccating tube 11, etc. SiH2 reacts with an aqueous solution of an alkali according to the formula, and 1mol of SiH2 gives 3mol of hydrogen, which corresponds to three times the amount of hydrogen released by the simple heating of the SiH2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for releasing hydrogen from a hydrogen storage material and an apparatus for carrying out the method.

In the specification of Japanese Patent Application No. 57-13125, - (SL horse), L
- Hydrogen storage materials are described that contain bonded chains and a four-coordinated Si lattice and store 60 to 70 atoms of hydrogen.

This hydrogen storage material absorbs silane gas at a pressure of 0.1 to 1QT.
subjected to glow discharge or sputtering under orr;
It is produced by depositing a powdered product on a cooling surface and contains a large amount of hydrogen, making it extremely useful as a hydrogen storage material.

When utilizing the hydrogen stored in this hydrogen storage material, the hydrogen storage material must be heated to 250° C.
Hydrogen was released by heating to a temperature of . When such a hydrogen release method is used, the hydrogen storage material can be used repeatedly since the material remaining after hydrogen release can be allowed to store hydrogen again at an appropriate temperature and pressure. On the other hand, it has the following drawbacks: (1) The hydrogen storage material must be housed in an airtight container and heated under conditions that prevent it from coming into contact with air. If this is not the case, the heating performed to release hydrogen will oxidize to produce F3i0□, H2O. (2) The substance gradually deteriorates due to repeated release and storage of hydrogen, and its hydrogen storage capacity decreases.

(3) It is not possible to release all the stored hydrogen.

Releasing all the hydrogen results in material degradation (including oxidation); (4) high energy consumption is involved to obtain a hydrogen release temperature of approximately 250C; In particular, hydrogen storage materials made of silicon are extremely disadvantageous because they can safely be heated up to 500C in order to release the stored hydrogen.

The purpose of the present invention is to
An object of the present invention is to provide an excellent method for releasing hydrogen without the above-mentioned drawbacks, and an apparatus for carrying out the method.

The method for releasing hydrogen from a hydrogen storage material according to the present invention is characterized by reacting a silicon-containing hydrogen storage material with an alkaline water bath liquid.

According to the method of the present invention, a silicon-containing hydrogen storage material is dissolved in an alkaline aqueous solution at room temperature, and at this time the following chemical reaction takes place: E3iH2+ 2NaOH+H20-+ Na2F3i
03+ It is clear from the reaction equation of 3 horses that 5, 5L
) 6 moles of hydrogen are obtained at room temperature from 121 moles. Also,
21 mole of SiH or 1 mole of H2O was decomposed in the presence of an alkali, indicating that water decomposition is carried out more favorably by chemical reaction than by electrolysis.

An example in which hydrogen is continuously released from a silicon-containing hydrogen storage material according to the present invention will be described below.

Example FIG. 1 shows a hydrogen release flowchart according to the present invention.

A 60% by weight slurry of silicon-containing hydrogen storage material (StH2) produced as described in Japanese Patent Application No. JM57-13125 is prepared in tank 1. - Put caustic soda and water into tank 2 to prepare a 10% Nc=OH aqueous solution. It is preferable to input 5jH2 and NaOH into each tank from the upper input port at appropriate times to keep the liquid stirring in the tank constant at all times. Then valves 3 and 4 are opened and pumps 5 and 6 are activated to pump the SiH2 slurry and N
The aOH solution is pressurized to 1 to 2 kIA thin 2, injected from nozzles 8 in one reactor Z, brought into contact in one reactor, and reacted instantaneously. The position of the nozzle is not limited to the top and bottom, but may be placed on the left and right, as long as the two liquids collide with each other. The hydrogen gas generated by the reaction is led to a gas-liquid separator 9 to remove moisture from the gas. In order to maintain the pressure of the generated hydrogen gas at a predetermined value, the pressure gauge 10 attached to the gas-liquid separator and pumps 5 and 6 are electrically linked to control the output of the pumps. Si sent to
The amount of hydrogen gas generated is kept constant by adjusting the amount of H2 and NaOH. The hydrogen gas that has passed through the gas-liquid separator is, for example, Ca
It passes through a drying pipe 11 filled with Cl2, and is controlled by a flow rate control valve 12 and a flow rate setting controller 16 so that the required flow rate is always obtained, and then subjected to a load. The N" S t Q 3 solution generated in the reactor is appropriately discharged by the valve 15. 14 is a flow meter. In this way, the pressure and flow rate of the released hydrogen gas are automatically controlled, and the raw material is Hydrogen gas can be continuously generated by sequentially charging tanks 1 and 2.

According to the present invention, by utilizing the chemical reaction between S t H2 and an alkaline aqueous solution, 3 moles of hydrogen can be released from 1 mole of 5LH2°, and this amount of hydrogen released is greater than when heated (S t H2 → sL+H2↑); ■Hydrogen is released by chemical reaction at room temperature, so there is no energy consumption for heating, etc.; ■Add 5 zHz raw materials and alkaline components to their respective tanks in a timely manner. can generate hydrogen continuously; ■ The pressure and flow rate of released hydrogen can be adjusted by the pump outlet and flow rate control valve; ■ NaE3i03 produced by the reaction is harmless and can be directly disposed of in sewage. Benefits such as being able to release water into the water can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a hydrogen release flowchart according to the present invention. Symbols in the figure = 1...5zHz tank, 2...NaOH
tank. 3.4.12.15...Valve, 6,5...Pump, 7
...Reaction chamber. 8... Nozzle, 9... Gas-liquid separator, 10... Pressure gauge. 11...Drying tube, 16...Flow rate setting controller, 14.
··Flowmeter.

Claims (1)

[Claims] A method for releasing hydrogen from a silicon-containing hydrogen storage material, which comprises reacting a silicon-containing hydrogen storage material (S t H2) with an alkaline aqueous solution. 2) A tank containing a slurry of silicon-containing hydrogen storage material, a tank containing an alkaline water bath liquid, and a reaction chamber with two nozzles inside the chamber.1 Gas-liquid separation device into which hydrogen released from the reaction chamber is introduced, and drying. A hydrogen release device comprising a tube and a flow rate setting controller.