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US 5,972,196 AGranted
Electrochemical production of ozone and hydrogen peroxide
AssigneeLynntech, Inc.
InventorsOliver J. Murphy, G. Duncan Hitchens
Life of this patent
Estimating the term…
Abstract
Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganisms and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.
Claims25
A method comprising:
- providing an electrochemical cell comprising an ionically conducting membrane in intimate contact between an anode and a cathode having a cathodic catalyst layer and a gas diffusion layer, wherein the gas diffusion layer includes hydrophobic pathways and hydrophilic pathways therethrough;
- providing a power supply having a positive terminal coupled to the anode and a negative terminal coupled to the cathode;
- supplying liquid water to the anode;
- supplying oxygen gas through the hydrophobic pathways of the gas diffusion layer to the cathodic catalyst layer;
- oxidizing water at the anode to produce ozone and hydrogen ions;
- electroosmotically transporting water along with the hydrogen ions through the ionically conducting membrane to the cathodic catalyst layer;
- reducing the oxygen at the cathodic catalyst layer to produce hydrogen peroxide;
- and
- withdrawing the hydrogen peroxide and the electroosmotically transported water from the cathodic catalyst layer through the hydrophilic pathways of the gas diffusion layer.
6 more elements
A method for the synthesis of chemicals in an electrochemical cell with a cathode having a gas diffusion layer and a cathodic catalyst layer and an anode having a porous substrate and an anodic catalyst layer, comprising the steps of:
- supplying oxygen gas through a first flow field to a first surface of the gas diffusion layer;
- passing oxygen through hydrophobic pathways in the gas diffusion layer to the cathodic catalyst layer along a second surface of the gas diffusion layer;
- supplying liquid water through a second flow field to a first surface of the porous substrate;
- passing liquid water through the porous substrate to the anodic catalyst layer along a second surface of the porous substrate;
- providing an ionically conducting membrane in intimate contact between the cathodic catalyst layer and the anodic catalyst layer;
- providing a power supply having a positive terminal coupled to the anodic catalyst and a negative terminal coupled to the cathodic catalyst;
- oxidizing liquid water at the anodic catalyst to produce a mixture of oxygen and ozone gases, hydrogen ions, and electrons;
- conducting the hydrogen ions and liquid water through the membrane to the cathodic catalyst layer;
- conducting the electrons through the power supply to the cathodic catalyst;
- reducing oxygen at the cathodic catalyst layer to produce hydrogen peroxide;
- and
- withdrawing hydrogen peroxide and liquid water from the cathodic catalyst layer through hydrophilic pathways in the gas diffusion layer to the first flow field.
9 more elements
A method, comprising the steps of:
- supplying oxygen gas through a first flow field to a first surface of a gas diffusion layer, wherein the gas diffusion layer has hydrophobic pathways and hydrophilic pathways;
- passing oxygen through the hydrophobic pathways of the gas diffusion layer to a cathodic catalyst layer along a second surface of the gas diffusion layer;
- supplying water through a second flow field to a first surface of a porous substrate;
- passing water through the porous substrate to an anodic catalyst layer along a second surface of the porous substrate;
- providing an ionically conducting membrane in intimate contact between the cathodic catalyst layer and the anodic catalyst layer;
- providing a power supply having a positive terminal coupled to the anodic catalyst and a negative terminal coupled to the cathodic catalyst;
- oxidizing water at the anodic catalyst to produce a mixture of oxygen and ozone gases, hydrogen ions, and electrons;
- conducting the hydrogen ions and their water of hydration through the membrane to the cathodic catalyst layer;
- conducting the electrons through the power supply to the cathodic catalyst;
- reducing oxygen at the cathodic catalyst to produce hydrogen peroxide;
- and
- withdrawing hydrogen peroxide and water from the catalyst layer through the hydrophilic pathways of the gas diffusion layer to the first flow field.
9 more elements
Dependencies are inferred from the claim text.