EA034943B1 - Hydrogen cell and method for manifacturing same - Google Patents

Abstract

The invention provides a laboratory-type hydrogen cell design and manufacturing procedures for the hydrogen cell components. The weight of hydrogen produced by the cell depends mainly on the area of the electrodes involved in the hydrogen generation process. A prior art hydrogen cell according to patent US8152974B2 has flat electrodes, which restricts the potential for hydrogen yield increase due to structural capabilities for an increase in the electrode area. Reduction of mechanical strength with an increase in the flat electrode area is another factor that restricts the increase in the flat electrode area. It is suggested that this disadvantage (small area) is removed by building a hydrogen cell with cone electrodes close to a cylindrical shape. The distinctive features of the proposed invention features are higher reliability due to titanium powder modification by a glass-insulated microwire and centrifugation of cathode titanium powders which allow to separate powder particles so that finer particles are located closer to the ion-exchange membrane to decrease the probability of the membrane destruction.

Description

The present invention relates to the field of chemical engineering, in particular to laboratory devices for producing hydrogen by electrolysis.

From the current level of technology, the TsvetKhrom-8 electrolysis module (electrolyzer) is known, intended for the production of highly pure hydrogen and oxygen from deionized water by electrolysis using a solid-polymer proton-conducting membrane. Patents are known that describe the design of laboratory devices for producing hydrogen and oxygen, manufacturing processes for the manufacture of electrodes of electrochemical cells and methods for their use. These include patents:

US 8152974 B2;

US patent application No. US 20040105773;

application for international patent No.PCT / HU05 / 00046;

US Patent Application No. US 06828056 et al.

Closest to the claimed technical solution is patent US 8152974 B2, in which the scope of protection relates to the electrode, the method of its manufacture and its use in an electrochemical cell. In accordance with the description of the cell is a flat metal electrodes made of titanium powders and separated by a proton membrane. When voltage is applied to the electrodes, water decomposes into hydrogen and oxygen, which are sent to receivers through their channels. The electrodes are made of titanium powder by pressure or sintering. Moreover, in the manufacture of the electrode, on the side of which hydrogen is formed, it is layered - a finer powder with lower porosity is placed on the membrane. The technology of manufacturing layers in bulk. The selection of the layer thickness is critical: a too thin electrode can be destroyed as a result of the mechanical load created by the high hydrogen pressure that arises during operation. Too thick an electrode reduces the efficiency of the material flow inside it. Based on this, the establishment (determination) of the average pore size and thickness of the electrodes requires careful consideration and technology. The disadvantage of the prototype is the low productivity of hydrogen production, determined by the small area of the electrodes, limited by the transverse dimensions of the chamber, and a decrease in the strength of flat electrodes with an increase in their area.

The problem to which the invention is directed is to increase the productivity of hydrogen production, simplify the manufacturing technology of the device, increase the reliability of the device and increase the strength of the electrodes. This problem is solved due to the fact that the claimed invention is a device consisting of electrodes separated by a proton membrane made of titanium powders by sintering and in contact with metal carriers coated with catalysts located in a plastic base covered by a plastic cover, having holes and sealed inlets for supplying deionized water, electricity and installation of a device for measuring the water level and outlets for oxygen, water and hydrogen, characterized in that the electrodes, membrane and carriers are made in the form of truncated cones located vertically with the top downward, and the generatrices of the cone make up axis angle within 5-30 °.

The electrodes can be made of titanium powder with a modification of their lengths of microwire in glass insulation with a length of 0.5-3.5 mm and sintered in a vacuum oven at a softening temperature of glass of 600-700 ° C. Before sintering, the cathode electrode is formed in a flask, the outer electrode of which is a titanium carrier, and the internal fake electrode (matrix) is made of stainless steel, the generators of which are parallel and spaced from each other at a distance of 2.5-3.5 mm.

Titanium powder is poured into the flask, it is mounted vertically and centrifuged at the angular speed necessary to create a uniform distribution of powder particles by their size in the electrode section. In this case, fine powders are located closer to the inner steel electrode, whose place will be taken by the membrane, which significantly reduces the probability of violating the integrity of the membrane adjacent to the surface of the powder. The anode electrode is made by sintering titanium powder also with its modification by microwire segments in glass insulation in the form consisting of an external titanium carrier and an internal steel cone electrode. Centrifugation is not used here. After the sintering procedure, the steel electrodes are removed from the molds, and the electrodes formed from titanium powder on titanium carriers and the membrane are collected in a block.

The technical result provided by the given set of features is to increase the productivity of hydrogen.

The invention is illustrated by drawings of FIG. 1 and 2, which depict sections of the electrolyzer.

The electrolyzer of FIG. 1 and 2, consists of two porous electrodes 1 and 2, made of titanium powders, modified with microwire segments in glass insulation, separated by a proton exchange membrane 3, made in the form of truncated cones located on thin-walled titanium carriers and placed in a cone-shaped recess of the base 4 made from insulating material, and tightly covered with a conical cover 5 made

- 1,034943 also made of insulating material. The surfaces of the base and the cover in contact with the carriers 6 and 7 are equipped with channels for supplying water and removing oxygen and hydrogen. A high pressure, of the order of hundreds of atmospheres, is created in the electrolyzer. Therefore, the lid and the base, separated by a seal 9, are fastened by metal rods 10 passing through the metal hoops 11 and 12. The surfaces of the carriers, base, electrodes, membranes and lids should fit snugly against each other. In order to avoid deformation of the membrane during assembly and sealing, a plastic ring 13 is installed in the upper part of the base, on the inner polished surface of which the edge of the membrane is installed, which allows pressing the cover against the base to avoid deformation of the membrane and the upper part of the titanium electrode. The ring on the periphery has recesses transverse to the surface, through which hydrogen formed passes at the base – cap interface. Hydrogen through the side openings in the ring enters the outlet in the lid and is directed to the consumer through the outlet pipe 14. The joints of the electrodes, carriers and the membrane with the base and the cover are sealed with O-rings 15 and 16. Water inlets 8, oxygen and water outlets through the pipe 17 and hydrogen 14 are sealed at the joints with the cover and the base, which are tightened with nuts 18. An electrical voltage is applied to input 19 and pipe 17.

A method of manufacturing an electrolyzer is as follows.

1. Prepare a mixture of titanium powder with pieces of microwire in glass insulation with a length of 1.53.5 mm in volume ratio to the powder 1: 5-1: 10.

2. Cover part of the inner surface of the titanium carrier 6 with a catalyst.

3. A container is assembled from a titanium perforated cone (carrier) 6 made of a strip 0.5-0.7 mm thick and a stainless steel fake electrode of the same thickness located coaxially at a distance of 2.5-3.5 mm from each other .

4. Fall asleep the mixture between titanium and steel electrodes.

5. Centrifuged the container with the mixture at an angular velocity, ensuring the location of large particles to the titanium wall and small to the false electrode.

6. Sinter the mixture in a vacuum oven at a temperature of 600-700 ° C.

7. Remove the false electrode.

8. Perform operations 3, 6 and 7 with the anode electrodes: collect the container, fill the mixture and remove the false electrode.

9. Place the seal 15 in the bottom of the base.

10. Place the cathode electrode 1 with the carrier 6 in the base 4.

11. Connect the cathode carrier 6 with the input of electricity 19.

12. Strengthen the insulating ring 13 in the base 4.

13. Placed on the anode electrode 2 membrane 3.

14. Place the anode electrode with the carrier, the membrane and the pipe 17 connected to the carrier at the base.

15. Install the seals 16 and 9 on the insulating ring 13 and the base 4.

16. Install the cover 5.

17. Pull the cover to the base with nuts.

18. Install a water inlet tube 8 in the central hole.

19. Install a water level sensor (not shown) on the side surface of the base.

The cell operates when filling its volume with deionized water through the tube 8 when applying voltage to the electrodes 1 and 2 through the pipe 17 and the input 19. Hydrogen leaves the cell through the pipe 14, oxygen and excess water through the pipe 17.

Claims (4)

CLAIM 1. The electrolyzer, consisting of a base and a cover of polymer insulating material, in which holes are provided for installing sealed inlets for supplying deionized water, electric voltage, placement of water level indicators and outlets of oxygen, water and hydrogen, and electrodes separated by proton exchange are installed in the base cavity membrane and titanium carriers, the working surfaces of which are coated with a catalyst, characterized in that the electrodes, membrane and carriers are made in the form of truncated cones, coaxially located with the vertex downward relative to the vertical axis in the base cavity, and the generators of the cones are inclined to the axis at an angle of 5 to 30 ° moreover, the electrodes are made of titanium powder modified with micron wire segments in glass insulation 1.5-3.5 mm long with a modifier concentration in the powder (by volume) from 1: 5 to 1:10. 2. A method of manufacturing an electrolyzer according to claim 1, characterized in that each of the electrodes is sintered from titanium powder at a temperature of 600-700 ° C together with a stainless steel matrix in vacuum, and the generators of the truncated cones installed coaxially are placed at a distance of 2, 53.5 mm required to achieve a given electrode wall thickness. 3. The method according to claim 2, characterized in that the cathode electrode together with the carrier, the matrix and - 2 034943 a mixture of titanium powder and pieces of micron wire in glass insulation before sintering is subjected to centrifugation by rotation of the base with a lid with an angular speed sufficient to separate the particles of the granular mixture into fractions and uniform distribution of large particles on the outside of the carrier. 4. The method according to claim 2 and 3, characterized in that before assembling the electrolyzer, the stainless steel molding elements (matrix) are removed, and the cathode and anode electrodes are assembled into a block and a proton exchange membrane is installed between them.