Method of enhancing corrosion resistance of oxidizable materials and components made therefrom
AssigneePurdue Research Foundation
InventorKenneth H. Sandhage
Life of this patent
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Abstract
Methods of enhancing the corrosion resistance of an oxidizable material exposed to a supercritical fluid is disclosed One method includes placing a surface layer on an oxidizable material, and choosing a buffered supercritical fluid containing a reducing agent with the composition of the buffered supercritical fluid containing the reducing agent chosen to avoid the corrosion of the surface layer or reduce the rate of corrosion of the surface layer and avoid the corrosion of the oxidizable material or reduce the rate of corrosion of the oxidizable material at a temperature above the supercritical temperature and supercritical pressure of the supercritical fluid.
Claims24
A method of enhancing the corrosion resistance of an oxidizable material to an oxidizing fluid that is corrosive to the oxidizable material, the method comprising:
- forming a buffered mixture of carbon dioxide as the oxidizing fluid and carbon monoxide as a reducing species that reduces the thermodynamic driving for reaction of the oxidizing fluid with the oxidizable material, the buffered mixture containing a ratio of the carbon monoxide fugacity to the carbon dioxide fugacity of at least 0.0000153;
- depositing a surface layer containing copper on a surface of the oxidizable material;
- and
- with the buffered mixture at a temperature of at least 750° C. and a pressure at or above 7.4 MPa to result in the buffered mixture being a buffered supercritical fluid, contacting the surface layer with the buffered supercritical fluid, the carbon monoxide of the reducing species rendering the copper of the surface layer inert to the buffered supercritical fluid and reducing the thermodynamic driving force for oxidative corrosion of the oxidizable material by the carbon dioxide of the oxidizing fluid.
A method of using a corrosion-resistant component having an oxidizable material and exposing the corrosion-resistant component to an oxidizing fluid that is corrosive to the oxidizable material, the method comprising:
- forming a buffered mixture of carbon dioxide as the oxidizing fluid and carbon monoxide as a reducing species that reduces the thermodynamic driving for reaction of the oxidizing fluid with the oxidizable material, the buffered mixture containing a ratio of the carbon monoxide fugacity to the carbon dioxide fugacity of at least 0.0000153;
- depositing a surface layer containing copper on a surface of the oxidizable material;
- and
- with the buffered mixture at a temperature of at least 750° C. and a pressure at or above 7.4 MPa to result in the buffered mixture being a buffered supercritical fluid, contacting the surface layer with the buffered supercritical fluid, the carbon monoxide of the reducing species rendering the copper of the surface layer inert to the buffered supercritical fluid and reducing the thermodynamic driving force for oxidative corrosion of the oxidizable material by the carbon dioxide of the oxidizing fluid.
A method of operating a power system with a passageway formed by an oxidizable material with a surface layer that contains a copper material, the method comprising:
- heating a working fluid of the power system to a temperature of at least 750° C. and a pressure at or above 7.4 MPa to result in the working fluid being a buffered supercritical fluid of carbon dioxide as an oxidizing fluid and carbon monoxide as a reducing species at a ratio of at least 0.0000153 of the carbon monoxide fugacity to the carbon dioxide fugacity;
- and
- rendering the copper material of the surface layer inert to the buffered supercritical fluid by passing the buffered supercritical fluid through the passageway so that the carbon monoxide therein renders the copper material inert to the carbon dioxide therein.
A method of rendering inert a surface layer on an oxidizable material in a heat exchanger or a power system, the method comprising:
- forming a buffered mixture of carbon dioxide as an oxidizing fluid and carbon monoxide as a reducing species that reduces the thermodynamic driving for reaction of the oxidizing fluid with the oxidizable material, the buffered mixture containing a ratio of the carbon monoxide fugacity to the carbon dioxide fugacity of at least 0.0000153;
- depositing the surface layer containing copper on a surface of the oxidizable material;
- and
- with the buffered mixture at a temperature of at least 750° C. and a pressure at or above 7.4 MPa to result in the buffered mixture being a buffered supercritical fluid, contacting the surface layer with the buffered supercritical fluid, the carbon monoxide of the reducing species rendering the copper of the surface layer inert to the buffered supercritical fluid and reducing the thermodynamic driving force for oxidative corrosion of the oxidizable material by the carbon dioxide of the oxidizing fluid.
Dependencies are inferred from the claim text.