Bipolar zero-gap electrolytic cell

Abstract

A bipolar zero-gap electrolytic cell comprising an anode comprising an anode substrate constituted of a titanium expanded metal or titanium metal net of 25 to 70% opening ratio, which anode after coating the substrate with a catalyst has a surface of 5 to 50 mum unevenness difference maximum and has a thickness of 0.7 to 2.0 mm. In this electrolytic cell, the possibility of breakage of ion exchange membrane is low, and the anolyte and catholyte have a concentration distribution falling within given range. With this electrolytic cell, stable electrolysis can be performed for a prolonged period of time with less variation of cell internal pressure.

Description

technical field [0001] The invention relates to a bipolar zero-spacing electrolyzer. [0002] This is a bipolar electrolytic cell of a pressure filter type electrolytic cell formed by arranging a plurality of bipolar electrolytic cells through cation exchange membranes. Composition, wherein there are at least two layers in the above-mentioned cathode chamber: a conductive cushion (cushion mat) layer and a cathode layer for hydrogen generation, the cathode layer for hydrogen generation is located on the conductive cushion layer and overlaps with the part in contact with the cation exchange membrane. [0003] This electrolytic cell is characterized in that: the material constituting the anode is titanium expanded metal or titanium wire mesh (gold mesh) with an opening ratio of 25% to 70%, and the catalyst is applied to the above material. , the maximum unevenness of the anode surface is 5μm-50μm, and the thickness is 0.7mm-2.0mm. Background technique [0004] Various proposa...

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Problems solved by technology

[0011] In JP-A No. 61-19789 and JP-A-63-11686, although it is considered that the gas and electrolyte are not pumped to the upper part but are pumped downward, the liquid and gas are still sometimes discharged in mixed phases, which cannot prevent Vibration occurs in the unit electrolyzer

In addition, in order to make the electrolyte concentration inside the tank uniform, a conductive dispersion or a current distribution member that can circulate the electrolyte inside is provided, but the disadvantage is that the structure inside the electrolytic tank becomes complicated.

[0012] In the official publication No. 57-153376, as a countermeasure to prevent vibration in the electrolytic tank, the scheme of the wave-absorbing plate is proposed, but only by this scheme can not obtain sufficient wave-absorbing effect, and cannot completely prevent vibration caused by vibration in the electrolytic tank. Vibration caused by pressure changes

[0013] In JP-A-4-289184 and JP-A-8-100286, in order to make the electrolyte in the tank uniform, a cylindrical conduit and a downcomer (downcomer) that can circulate the electrolyte inside are provided, but The structure in the electrolyzer is still relatively complicated, and the manufacturing cost is relatively high, or when 5kA / m 2 When the above high current density is electrolyzed, the concentration distribution of the electrolyte will have a great adverse effect on the ion exchange membrane.

[0014] Further, these publications all consider that the gas-liquid separation chamber has a sufficiently large space to some extent, and it is drawn out in a downward or horizontal gas-liquid separation state to prevent vibration, but at 5kA / m 2 Vibration still occurs at higher current densities above

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