Electrolytic cells

Abstract

An electrolytic cell for producing hydrogen peroxide includes an anode, a cathode and an intermediate membrane. The anode is associated with a first electrolyte and the cathode is associated with a second electrolyte. The use of two electrolytes associated with the respective electrodes permits the user to select the most suitable salt solutions for each electrode and so avoid production of gases and by-products unsuitable for a domestic environment. Thus, the electrolytic cell is suitable for use in an automatic dishwasher.

Description

REFERENCE TO RELATED APPLICATIONS[0001]This application is a national stage application under 35 USC 371 of International Application No. PCT / GB2007 / 001214, filed Apr. 2, 2007, which claims the priority of United Kingdom Application No. 0607279.7, filed Apr. 11, 2006, the contents of both of which prior applications are incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention relates to electrolytic cells, and especially to such cells arranged to produce hydrogen peroxide in, for example, an automatic dishwasher.BACKGROUND OF THE INVENTION[0003]In a conventional automatic dishwasher, detergents are employed to produce a wash liquid for use on dirty items placed in the dishwasher for washing. However, such detergents can decompose to produce pollutants when the wash liquid is released to the environment.[0004]It has been proposed to use a solution of hydrogen peroxide as a wash liquid in an automatic dishwasher. The advantage of hydrogen peroxide is that it decompo...

AI Technical Summary

Benefits of technology

[0008]The provision of two electrolytes associated with the respective electrodes permits the user to select the most suitable salt solutions for each electrode. For example, a metal chloride solution may be employed in connection with the anode to provide a cheap and plentiful electrolyte, with a different metal salt solution being used as the electrolyte associated with the cathode so as to prevent the generation of harmful by-products, such as chlorine gas.

Problems solved by technology

However, such detergents can decompose to produce pollutants when the wash liquid is released to the environment.

However, hydrogen peroxide is unstable and is not capable of being stored for long periods without decomposing.

A problem which may be encountered with the electrolysis of water is that, in order to produce good yields of hydrogen peroxide, the water must be electrically conductive.

However, water piped in from the local main supply, which would be the most convenient source of water, is not particularly conductive.

However, the electrochemical reaction involved in the production of hydrogen peroxide causes chlorine gas to be produced at the anode, which is extremely poisonous.

However, these proposals add to the cost and / or complexity of the electrolytic cell.

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