Method and composition for removing sulfide-containing scale from metal surfaces
AssigneeThe Dow Chemical Company
InventorGary R. Buske
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Abstract
An aqueous cleaning composition is described herein which contains glyoxylic acid dissolved in an aqueous non-oxidizing acid. This cleaning solution is effective in removing acid-soluble, sulfide-containing scale from metal surfaces (e.g. refinery equipment) without the evolution of gaseous hydrogen sulfide.
Claims9
An aqueous acid composition comprising an aqueous non-oxidizing acid having glyoxlic acid dissolved therein;
- said composition having, as one of its chemical properties, the capability of dissolving acid-soluble, sulfide-containing scale from a metal surface without the evolution of hydrogen sulfide gas.
In the method of chemically cleaning acid-soluble, sulfide-containing scale from a metal surface comprising contacting said scale with an aqueous acid cleaning composition comprising an aqueous non-oxidizing acid having at least one aldehyde dissolved or dispersed therein, which aldehyde is present in an amount at least sufficient to prevent or substantially prevent the evolution of hydrogen sulfide gas the improvement comprising using glyoxlic acid as said aldehyde.
Dependencies are inferred from the claim text.