Continuous electrolysis method with electrolytic bath for polysulfide production and electrolysis device for implementing the same

Patent metadata

Field	Value
Publication number	US-10253422-B2
Application number	US-201815917847-A
Country	US
Kind code	B2
Filing date	Mar 12, 2018
Priority date	Oct 1, 2012
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

An electrolysis method of preventing the voltage of an electrolytic bath from rising over time without halting electrolysis and an electrolysis device for executing the method are provided such that: in operation of a two-compartment electrolytic bath, which has a membrane partitioning an anode compartment from a cathode compartment and in which a sulfide ion-containing white liquor for use in a pulp production process is fed into the anode compartment while direct current is supplied to the electrolytic bath to produce polysulfide in the anode compartment through electrolysis, and a sulfide ion-containing white liquor for use in a pulp production process that contains at least one of a scale cleaning agent and a scale inhibitor is fed to the anode compartment.

First claim

The invention claimed is:

1. An electrolysis method of reducing maintenance frequency and preventing the voltage of an electrolytic bath from rising over time, using a two-compartment electrolytic bath, which has a membrane with which an anode compartment is partitioned from a cathode compartment and in which a sulfide ion-containing white liquor for use in a pulp production process is fed into the anode compartment while direct current is supplied to the electrolytic bath to produce polysulfide in the anode compartment through electrolysis;
the method comprising:
carrying out electrolysis after the anode compartment and an anode solution feed line have been cleaned with an aqueous inorganic acid solution or a scale cleaning agent during a halt of the electrolysis, and
feeding, during the afterward electrolysis, at least one of a scale cleaning agent and a scale inhibitor to the sulfide ion-containing white liquor for use in the pulp production process during circulation of the sulfide ion-containing white liquor in between a white liquor tank and the anode compartment.

2. The electrolysis method of reducing maintenance frequency and preventing the voltage of an electrolytic bath from rising over time according to claim 1 , characterized in that:
the scale cleaning agent in the white liquor contains a chelating agent.

3. The electrolysis method of reducing maintenance frequency and preventing the voltage of an electrolytic bath from rising over time according to claim characterized in that:
the scale inhibitor in the white liquor contains a maleic acid-type polymer.

Assignees

• Jujo Paper Co Ltd
• Permelec Electrode Ltd

Inventors

• Suyama Kenichiro
• Kurosu Kazuhiro
• Kato Masaaki
• Otsu Hideo

Classifications

• C25B1/14

  Alkali metal compounds · CPC title

• C25B1/00 Primary

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C25B15/08

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title

• C02F2201/4611

  Fluid flow · CPC title

• D21C11/0042

  Fractionating or concentration of spent liquors by special methods (concentration by evaporation D21C11/10) · CPC title