WO2009070938A1

WO2009070938A1 - Multielectrodes-type ion-membrane electrolytic cell with oxygen-cathodes

Info

Publication number: WO2009070938A1
Application number: PCT/CN2007/071152
Authority: WO
Inventors: Lianghu Zhang; Jianjun Wang; Feng Wang; Haiyao Li; Lide Guo; Pai Zhang
Original assignee: Bluestar (Beijing) Chemical Machinery Co., Ltd.; Beijing University Of Chemical Technology; China National Bluestar (Group) Co., Ltd
Priority date: 2007-12-03
Filing date: 2007-12-03
Publication date: 2009-06-11
Also published as: CN101849037A; CN101849037B

Abstract

A multielectrodes-type ion-membrane electrolytic cell with oxygen-cathodes, which belongs to chlor-alkali industry. The essential of the present invention is the improvement at the side of the oxygen-cathode, at which the cathode panel in the cathode chamber is connected with the anode panel in the anode chamber by welding several titanium-steel composite plates between them, and a porous electrode-holder is connected with the cathode panel in the cathode chamber by welding several cathode ribs between them to form a gas chamber. The gas diffusion electrode is welded onto the porous electrode-holder, and the periphery of the gas diffusion electrode is connected to the frame by sealing and securing. Several holes are arranged at the lower part of the upside square tube-type frame towards the cathode chamber , and the holes are uniformly distributed along the longitudinal direction of the upside square tube-type frame. Moreover, Several holes are arranged at the upper part of the downside square-tube of the frame towards the cathode chamber , and the holes are uniformly distributed along the longitudinal direction of the downside square tube-type frame. The present invention possesses appropriate structure and lower operation cost.

Description

Technical field

The invention belongs to the chlor-alkali industrial technology, and particularly relates to a bipolar ion membrane electrolysis unit tank.

Background technique

The electrodes at both ends of the bipolar cell are connected to the positive and negative terminals of the DC power source to form an anode or a cathode. When a current flows through the electrolytic cell through the series connected electrodes, one side of the intermediate electrode is an anode and the other side is a cathode, so that it has bipolarity. When the total area of the electrodes is the same, the current of the bipolar type electrolytic cell is smaller and the voltage is higher, and the investment of the required DC power source is saved compared to the single pole type. Usually, the repolarization type generally adopts a filter press structure and is relatively compact. The cell consists of a cell, an anode and a cathode, and most of the separator separates the anode and cathode compartments. According to the different electrolytes, it is divided into three types: aqueous solution electrolysis tank, molten salt electrolysis tank and non-aqueous solution electrolysis tank. When direct current passes through the electrolytic cell, an oxidation reaction occurs at the interface between the anode and the solution, and a reduction reaction occurs at the interface between the cathode and the solution to obtain a desired product. Optimal design of the cell structure and reasonable selection of electrodes and separator materials are key factors in improving current efficiency, reducing cell voltage, and saving energy.

Usually, the residence time of the electrolyte in the electrolytic cell not only affects the production capacity of the equipment, but also affects the current efficiency of the electrolysis process in some cases, such as electrolysis of sodium chlorate, intermediate product hypochlorous acid (HC10). The chemical reaction rate with the hypochlorite ion (C103) is very slow, such as staying in the electrolytic cell for a long time, not only reducing the utilization rate of the electrolytic cell, but also the hypochlorite ion is oxidized on the surface of the anode or reduced on the surface of the cathode. Reduce current efficiency. Therefore, modern cell designs seek to reduce volume and allow electrolyte to flow rapidly along the electrode.

Summary of the invention The object of the present invention is to provide a bipolar oxygen cathode ion membrane electrolysis cell tank whose cathode side electrode structure is designed by using a gas diffusion cathode, which can reduce the DC power consumption per ton of alkali.

In order to achieve the above object, the technical solution of the present invention is as follows: The bipolar oxygen cathode ion membrane electrolysis cell slot comprises a slot frame formed by an upper frame square tube, a lower frame square tube and side frame square tubes. An anode chamber disk plate, a plurality of anode rib plates and an anode electrode are formed on the anode side of the groove frame to form an anode chamber, and an anode inlet nozzle is connected with the anode liquid separation tube, and a titanium-carbon steel composite is arranged on the cathode side of the unit groove. a plate, a plate-shaped cathode chamber disk plate, a plurality of cathode rib plates, an electrode support mesh, and a gas diffusion cathode, wherein the titanium layer of the titanium-carbon steel composite plate faces the anode side, and the carbon steel layer faces the cathode side; wherein, the cathode chamber disk The plate is welded to the anode chamber disk plate through a titanium-carbon steel composite plate, and the electrode support mesh is welded to the cathode chamber disk plate through a plurality of cathode rib plates to form a gas chamber, and the gas diffusion cathode is welded and connected to the electrode support mesh and the gas diffusion cathode The periphery of the square frame is sealed and connected to the slot; the lower corner of the upper frame square tube faces the cathode chamber, and a plurality of holes are formed along the length of the upper frame square tube a uniform distribution of the degree direction; the upper corner of the lower frame square tube facing the cathode chamber has a plurality of holes and the plurality of holes are evenly distributed along the length direction of the lower frame square tube; the cathode inlet connection tube is connected to the lower frame square tube The cathode outlet nozzle is in communication with the upper frame square tube; the gas inlet nozzle communicates with the gas chamber through the upper frame square tube, and the water outlet nozzle communicates with the gas chamber through the lower frame square tube.

As a modification of the present invention, each of the cathode ribs is provided with a plurality of through holes, and the plurality of through holes are evenly distributed along the upper and lower directions of the cathode ribs.

As a further improvement of the present invention, a vapor-liquid separation device is disposed between the anode chamber disk plate and the plurality of anode rib plates at the upper portion of the anode chamber, and the vapor-liquid separation device includes a bending plate and a screen, and the folding The cross-sectional shape of the curved plate is shaped, and the side of the plate is welded and sealed to the pan chamber, and a channel is disposed between the upper side and the side wall of the anode chamber disk; the screen is disposed at the periphery of the channel The bottom of the vapor-liquid separation device is provided with an anode outlet box connected to the anode and an anode outlet tube connected to the anode outlet box.

Working principle: As shown in Figure 9, when used, several unit slots according to the invention are selected according to the requirements of different devices. The anode side and the cathode side between adjacent unit slots pass through respective anode and cathode spacers. The upper ion membrane forms an electrolytic cell. The flow path of the current during the working process is: cathode disk plate, cathode rib plate, electrode support mesh, gas diffusion cathode, ion film, anode electrode, anode rib, plate, anode plate, composite plate, cathode plate, and so on.

The design points of the bipolar oxygen cathode ion membrane electrolysis unit cell of the present invention are as follows:

1. The anode electrolysis chamber, the cathode electrolysis chamber and the gas chamber are separately arranged, and the metal conductors are directly connected to each other;

2. The upper and lower frame square tubes serve not only as the support of the unit tank, but also as the cathode liquid inlet and outlet collecting pipe, the gas collecting pipe and the liquid dividing pipe;

3. A support net for conducting and supporting a gas diffusion cathode is disposed in the cathode chamber;

4. The anode sealing surface is made of titanium-palladium alloy or titanium-rhenium alloy with good crevice corrosion resistance, or coated with crevice corrosion resistance to improve the service life of the whole machine;

5. The screen structure of the vapor-liquid separation device separates the vapor and liquid of the vapor-liquid mixture generated by the electrolysis of the anode chamber to facilitate the discharge of the vapor-liquid mixture.

At present, the chlor-alkali industry produces 1 ton of caustic soda with a DC power consumption of about 2200 degrees. With the oxygen cathode electrolysis cell of the present invention, the DC power consumption per ton of alkali can be reduced to about 1600 degrees, and the energy saving is 20% to 30%, and the effect is very remarkable. The invention has the advantages of reasonable structure and low running cost, and has good promotion and application.

DRAWINGS 1 is a schematic view showing the overall structure of a bipolar oxygen cathode ion membrane electrolysis unit cell according to the present invention; FIG. 2 is a cross-sectional view taken along line A-A of FIG.

Figure 3 is a cross-sectional view taken along line B-B of Figure 2;

Figure 4 is a cross-sectional view taken along line C-C of Figure 1;

Figure 5 is a schematic view showing the structure of the left, right and upper sides of the screen 31 in the embodiment;

Figure 6 is a schematic view showing the structure of the four sides of the screen 31 being a folded structure in the embodiment; Figure 7 is a partial view of the D direction of Figure 5;

Figure 8 is a partial view taken along line E of Figure 6;

Figure 9 is a schematic diagram of an electrolytic cell composed of two repolarized oxygen cathode ion membrane electrolysis cell tanks.

detailed description

The specific embodiments are specifically described below in conjunction with the drawings.

As shown in FIG. 1 , FIG. 2 and FIG. 3 , the bipolar oxygen cathode ion membrane electrolysis unit tank of the embodiment includes a groove formed by an upper frame square tube 8 , a lower frame square tube 7 and side frame square tubes. a frame, an anode chamber disk plate 18, a plurality of anode rib plates 19 and an anode electrode 20 are formed on the anode side of the groove frame to form an anode chamber, and the anode inlet nozzle 1 is in communication with the anode liquid separation tube 2, and the groove frame content on the cathode side of the unit groove A titanium-carbon steel composite plate 13, a plate-shaped cathode chamber disk plate 14, a plurality of cathode ribs 15, an electrode support mesh 16, and a gas diffusion cathode 17 are disposed, and the titanium layer of the titanium-carbon steel composite plate 13 faces the anode side. The carbon steel layer may be 0. 5~3匪, preferably 1匪; the carbon steel layer may be 2~4mm, preferably 3mm.

The cathode chamber disk plate 14 is welded to the anode chamber disk plate 18 through the titanium-carbon steel composite plate 13 , and the electrode support mesh 16 is welded to the cathode chamber disk plate 18 through a plurality of cathode rib plates 15 to form a gas chamber. The gas diffusion cathode 17 is welded to the electrode support net 16 , and the periphery of the gas diffusion cathode 17 is sealedly connected to the groove frame;

The lower corner portion of the upper frame square tube 8 facing the cathode chamber is provided with a plurality of holes 81 having a diameter of Φ 3 Φ Φ 5TM and the plurality of holes 81 are evenly distributed along the length direction of the upper frame square tube 8; The upper corner portion of the lower frame square tube 7 facing the cathode chamber is provided with a plurality of holes 71 having a diameter of Φ 1 Φ Φ 3TM and the plurality of holes 71 are evenly distributed along the length direction of the lower frame square tube 7;

As shown in FIG. 4, the cathode inlet nozzle 6 communicates with the lower frame square tube 7, and the cathode outlet nozzle 10 communicates with the upper frame square tube 8; the gas inlet nozzle 11 communicates with the gas chamber through the upper frame square tube 8, the water outlet The nozzle 12 communicates with the gas chamber through the lower frame square tube 7.

Preferably, each of the cathode ribs 15 has a plurality of through holes 151 formed therein, and the plurality of through holes 151 are evenly distributed along the upper and lower directions of the cathode ribs 15.

More preferably, a vapor-liquid separation device 3 is disposed between the anode chamber disk plate 18 and the plurality of anode rib plates 19 at the upper portion of the anode chamber, and the vapor-liquid separation device includes a bending plate 30 and a screen 31. The cross-sectional shape of the bending plate 30 is shaped, and the side edges thereof are welded and sealed to the male and female chamber disk plates 18, and a passage 33 is left between the upper side and the side wall of the anode chamber disk plate 18; the screen 31 It is disposed at the channel 33 and its periphery is sealedly connected to the periphery of the channel 33; at one end of the vapor-liquid separation device 3, an anode outlet case 4 connected thereto and an anode outlet port 5 communicating with the anode outlet case 4 are disposed.

The sieve mesh may be a 2X4 or 3X5 pull net plate, or a Φ 0. 8~ Φ 1 titanium wire woven 8~10 mesh woven mesh may be used.

As shown in FIG. 5 and FIG. 7, the left, right and upper sides of the screen 31 are a folded structure, and the screen 31 is disposed on the outer side of the bent plate 30 and the left, right and upper folded portions thereof. They are fixedly connected to the left, right and upper side walls of the pan chamber panel 18, respectively. In addition, as shown in FIG. 6 and FIG. 8 , the screen 31 may also be different from the above structure, and the four sides are folded, and the screen 31 is disposed on the inner side of the bending plate 30 and the opening faces the bending plate 30 . The left, right and upper folded portions of the screen 31 are fixedly coupled to the left, right and upper side walls of the male and female chamber trays 18, respectively, and the lower folded edges thereof are fixedly coupled to the bent plate 30.

Still more preferably, the material of the anode sealing surface is selected from a titanium palladium alloy or a titanium niobium alloy. It is also possible to apply a corrosion-resistant coating to the anode sealing surface, for example, a palladium coating or a ruthenium coating.

As shown in FIG. 9, a plurality of unit slots of the present invention are selected according to the requirements of different devices, and the anode side and the cathode side between adjacent unit slots are sandwiched with ion membranes 41 through respective anode pads 42 and cathode pads 40. , forming an electrolytic cell.

During operation, the anolyte enters the anode liquid separation tube 2 in the electrolytic cell from the anode inlet nozzle 1 and then uniformly distributes a plurality of Φ 1~ Φ 3 mm small holes through the anode liquid separation tube 2 into the anode electrolysis chamber to generate chlorine gas by electrolysis. After that, the anolyte containing chlorine gas enters the vapor-liquid separation device 3 built in the electrolytic cell for preliminary separation, as shown in FIG. 5 and FIG. 7, the vapor-liquid equilibrium phase enters the anode outlet box 4 through the vapor-liquid equilibrium phase. The anode outlet nozzle 5 discharges the electrolysis unit tank. The catholyte enters the lower frame square tube of the electrolytic cell from the cathode inlet connecting pipe 6, and enters the cathode of the electrolytic cell through a plurality of Φ 1~Φ 3mm small holes 71 uniformly distributed on the upper corner of the cathode casing toward the upper corner of the cathode chamber. The cathode liquid is evenly distributed in the cathode chamber of the electrolytic cell, and the catholyte after electrolysis enters the upper frame of the electrolytic cell through a plurality of Φ 3 Φ 5 mm small holes 81 uniformly distributed on the upper corner of the cathode chamber 8 toward the lower corner of the cathode chamber. In the square tube 8, finally, the electrolytic cell tank is discharged from the cathode outlet connecting tube 10. The gas participating in the reaction enters the gas chamber of the electrolytic cell through the gas inlet nozzle 11 and ensures uniform distribution of the medium through the through hole 151 in the cathode rib 15 , and the water electrode combines with the hydrogen ions generated during the electrolysis to generate water, and the electrolysis product water is Water outlet 12 Deriving the electrolysis cell, unreacted oxygen and gas are led out of the electrolysis cell from the gas outlet nozzle 9. The above detailed description of the bipolar oxygen cathode ion membrane electrolysis unit cell of the present invention is only for explaining the present invention and is not intended to limit the technical solutions described in the embodiment. It will be understood by those skilled in the art that the present invention may be modified or equivalently replaced to achieve the same technical effect. For example, the gas outlet nozzle 9 may not be separately set, and the electrolysis product water and the unreacted gas may be taken over. 12 mixing and deriving the electrolytic cell; as long as the needs of use are met, it is within the scope of protection of this patent.

Claims

Claim

1. A bipolar oxygen cathode ion membrane electrolysis cell slot, comprising a trough frame formed by an upper frame square tube 8, a lower frame square tube 7 and two side frame square tubes, the anode side of which is welded with an anode chamber disk plate 18. A plurality of anode ribs 19 and anode electrodes 20 form an anode chamber, and an anode inlet nozzle 1 is in communication with the anode liquid separation tube 2, and is characterized by:

The slot on the cathode side of the unit slot is provided with a titanium-carbon steel composite plate 13, a plate-shaped cathode chamber disk plate 14, a plurality of cathode ribs 15, an electrode support mesh 16 and a gas diffusion cathode 17, the titanium-carbon steel The titanium layer of the composite plate 13 faces the anode side, and the carbon steel layer faces the cathode side; wherein, the cathode chamber disk plate 14 is welded to the anode chamber disk plate 18 through the titanium-carbon steel composite plate 13, and the electrode support mesh 16 passes through a plurality of cathode rib plates. 15 is welded to the cathode chamber disk plate 18 to form a gas chamber, and the gas diffusion cathode 17 is welded to the electrode support mesh 16;

The lower corner portion of the upper frame square tube 8 facing the cathode chamber is provided with a plurality of holes 81 and the plurality of holes 81 are evenly distributed along the length direction of the upper frame square tube 8;

The upper corner portion of the lower frame square tube 7 facing the cathode chamber is provided with a plurality of holes 71 and the plurality of holes 71 are evenly distributed along the length direction of the lower frame square tube 7;

The cathode inlet nozzle 6 is in communication with the lower frame square tube 7, and the cathode outlet nozzle 10 is connected to the upper frame square tube 8;

The gas inlet nozzle 11 communicates with the gas chamber through the upper frame square tube 8, and the water outlet nozzle 12 communicates with the gas chamber through the lower frame square tube 7.

2. The bipolar oxygen cathode ion-exchange membrane electrolysis cell according to claim 1, wherein the diameter of the hole 81 of the upper frame square tube 8 facing the lower corner of the cathode chamber is Φ 3 Φ Φ 5TM _; The diameter of the hole 71 of the lower frame square tube 7 facing the upper corner portion of the cathode chamber is Φ 1 to Φ 3TM.

3. The bipolar oxygen cathode ion-exchange membrane electrolysis unit cell according to claim 1, wherein each of the cathode ribs 15 is provided with a plurality of through holes 151, and the plurality of through holes 151 are along the cathode ribs. The upper and lower directions of the plate 15 are evenly distributed.

4. The bipolar oxygen cathode ion membrane electrolysis cell tank according to claim 1, wherein a vapor-liquid separation device is disposed between the anode chamber disk plate 18 and the plurality of anode rib plates 19 at an upper portion of the anode chamber. 3, the vapor-liquid separation device comprises a bending plate 30 and a screen 31, the sectional shape of the bending plate 30 is shaped, and the side of the bending plate 30 is welded and sealed with the solar disk plate 18, the upper side and the anode A passage 33 is disposed between the side walls of the chamber plate 18; the screen 31 is disposed at the passage 33 and has a periphery sealed to the periphery of the passage 33; and is connected at one end of the vapor-liquid separation device 3 The anode outlet box 4 and the anode outlet port 5 communicating with the anode outlet box 4 are provided.

The bipolar oxygen cathode ion-exchange membrane electrolysis unit cell according to claim 4, wherein the left, right and upper sides of the screen 31 are folded, and the screen 31 is disposed on the bending plate 30. The outer side and its left, right and upper folded portions are fixedly coupled to the left, right and upper side walls of the male and female chamber trays 18, respectively.

6. The bipolar oxygen cathode ion membrane electrolysis unit cell according to claim 4, wherein the four sides of the screen 31 are folded structures, and the screen 31 is disposed on the inner side of the bent plate 30 and is open. Toward the bending plate 30, the left, right and upper flange portions of the screen 31 are fixedly coupled to the left, right and upper side walls of the male and female chamber disk panels 18, respectively, and the lower flanged edges thereof are fixedly coupled to the bending plate 30.

The bipolar oxygen cathode ion membrane electrolysis unit cell according to claim 1, 2, 3, 4, 5 or 6, wherein the periphery of the gas diffusion cathode 17 is sealedly connected to the cell frame.

8. The bipolar oxygen cathode ion membrane electrolysis cell tank according to claim 7, wherein the material of the anode sealing surface is a titanium palladium alloy.

The bipolar oxygen membrane electrolysis cell tank according to claim 7, wherein the material of the anode sealing surface is made of a titanium-niobium alloy.

The bipolar ion-exchange membrane electrolysis cell tank according to claim 7, wherein the anode sealing surface is coated with a palladium coating.

The bipolar ion-exchange membrane electrolysis cell tank according to claim 7, wherein the anode sealing surface is coated with a ruthenium coating.