# US 2021/0276906 A1 · Use of percarboxylic acids for scale prevention in treatment systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276906 A1 - Document ID: US20210276906A1 - Status: Published application - Kind: A1 - Application number: 17/303,117 - Filed: 2021-05-20 - Published: 2021-09-09 - Earliest claimed: 2014-12-18 - Assignees: Ecolab USA Inc. - Applicants: Ecolab USA Inc. - Inventors: Ramakrishnan Balasubramanian; Brian Epps; Junzhong Li; Richard Staub; Victor Keasler - Web page: https://patentgrep.com/patent/US20210276906A1 ## CPC - C02F 5/10: using organic substances - C02F 1/50: by addition or application of a germicide or by oligodynamic treatment {(C02F1/4606, C02F1/467, C02F1/76 take precedence)} - C02F 5/02: Softening water by precipitation of the hardness - C02F 2101/10: Inorganic compounds - C02F 2101/101: {Sulfur compounds} - C02F 2101/12: Halogens or halogen-containing compounds - C02F 2101/203: {Iron or iron compound} - C02F 2103/10: from quarries or from mining activities - C02F 2103/365: {from petrochemical industry (e.g. refineries)} - C02F 2209/06: pH - C02F 2303/04: Disinfection - C02F 2303/22: Eliminating or preventing deposits, scale removal, scale prevention (C02F1/042, C02F1/4602, C02F5/00 take precedence) - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract Methods of employing peroxycarboxylic acid compositions for the prevention of scale formation and in some embodiments the removal of existing scale are disclosed. In particular, the scale inhibition properties of percarboxylic acids of varying chain lengths including C1-C22 provide effective scale inhibition and scale removal or destruction. Methods of employing peroxycarboxylic acid compositions for scale inhibition and/or removal are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. The methods provide suitable scale inhibition replacements and/or additives to known scale inhibitors. ## Claims ### Claim at position 1 1-97. (canceled) ### Claim 98 A method for reducing scale formation from a target comprising: contacting a target with at least about 2 ppm C1-C22 peroxycarboxylic acid composition, wherein the peroxycarboxylic acid does not include sulfoperoxycarboxylic acids, wherein the target is contacted at a pH below about 10.5, and wherein the contacting step is for a sufficient amount of time to reduce scale formation; and reducing said scale formation. ### Claim 99 (depends on 98) The method of claim 98, wherein the target comprises a water source in need of treatment to form a treated water source, a water source and a surface in contact therewith in need of treatment to form a treated water source, a water source and at least a portion of a medium, a container, an equipment, a system or a facility for producing, holding, processing, packaging, storing, or transporting pulp, or combinations thereof. ### Claim 100 (depends on 99) The method of claim 99, wherein the water source in need of treatment comprises fresh water, pond water, sea water, produced water, tower water or a combination thereof, and is used in oil and/or gas drilling operation. ### Claim 101 (depends on 1010) The method of claim 1010 wherein the water source or the peroxycarboxylic acid composition further comprises a friction reducer, a corrosion inhibitor or a viscosity enhancer. ### Claim 102 (depends on 99) The method of claim 99, wherein from about 2 ppm to about 10,000 ppm of said peroxycarboxylic acid composition is added to the water source. ### Claim 103 (depends on 98) The method of claim 98, wherein the percarboxylic acid composition comprises a C1-C22 percarboxylic acid, a C1-C22 carboxylic acid and hydrogen peroxide, wherein the C1-C22 percarboxylic acid comprises from about 1 wt-% to about 60 wt-%, the C1-C22 carboxylic acid comprises from about 10 wt-% to about 90 wt-%, and the hydrogen peroxide comprises from about 0.5 wt-% to about 25 wt-% of the percarboxylic acid composition. ### Claim 104 (depends on 98) The method of claim 98, wherein the C1-C22 percarboxylic acid is a C1-C22 peroxycarboxylic acid forming composition, wherein the C1-C22 peroxycarboxylic acid forming composition comprises an ester of polyhydric alcohol and C1-C22 carboxylic acid and hydrogen peroxide, wherein the ester of polyhydric alcohol and C1-C22 carboxylic acid comprises from about 50 wt-% to about 99 wt-% and the hydrogen peroxide comprises from about 0.1 wt-% to about 50 wt-% of the peroxycarboxylic acid forming composition. ### Claim 105 (depends on 98) The method of claim 98, wherein the pH of the target treated with the C1-C22 peroxycarboxylic acid composition is between about 3 and about 10.5. ### Claim 106 (depends on 98) The method of claim 98, wherein the scale is a phosphate scale, carbonate scale, chloride scale, sulfate scale and/or combinations thereof found in water sources employed for oil and gas operations, water cooling towers, recreational waters, warewash applications, clean-in-place applications, industrial equipment and process streams, a medium, a container, an equipment, a system or a facility for producing, holding, processing, packaging, storing, or transporting pulp and/or combinations thereof. ### Claim 107 (depends on 98) The method of claim 98, wherein the contacting step provides the peroxycarboxylic acid composition to the target for at least about 1 minute and by means of a spray, a fog, or a foam, or by dipping all or part of the target in a composition comprising the peroxycarboxylic acid composition, and wherein the contacting step is conducted at a temperature ranging from about 0° C. to about 130° C. ### Claim 108 (depends on 98) The method of claim 98, wherein the peroxycarboxylic acid composition further comprises or is combined at a target with an additional functional ingredient comprising a catalyst, stabilizing agent, pH buffering agent, acidulant, friction reducer, viscosity enhancer, defoaming agent, anti-redeposition agent, bleaching agent, solubility modifier, dispersant, metal protecting agent, corrosion inhibitor, additional biocide, additional scale inhibitor, sequestrant and/or chelating agent, peracid stabilizer, surfactant and/or antimicrobial agent, additional carboxylic acid, emulsion breaker, emulsion stabilizer, additional scale inhibitor such as an iron dissolver, fragrance and/or dye, rheology modifier or thickener, hydrotrope or coupler, buffer, solvent or combinations thereof. ### Claim 109 (depends on 98) The method of claim 98, wherein the microbial population in and/or on the target is reduced by at least one log10 and wherein the treatment with the peroxycarboxylic acid further removes iron sulfide from the target. ### Claim 110 A method for dissolving and removing scale from a target comprising: contacting a target with at least about 2 ppm C1-C22 peroxycarboxylic acid composition, wherein the peroxycarboxylic acid does not include sulfoperoxycarboxylic acids, wherein the target is contacted at a pH below about 10.5, and wherein the contacting step is for a sufficient amount of time to dissolve and remove scale from a target; and removing said scale, wherein said scale is an iron sulfide, an inorganic calcium component, or an inorganic sulfate. ### Claim 111 (depends on 110) The method of claim 110, wherein the target comprises a water source in need of treatment to form a treated water source, a water source and a surface in contact therewith in need of treatment to form a treated water source, a water source and at least a portion of a medium, a container, an equipment, a system or a facility for producing, holding, processing, packaging, storing, or transporting pulp, or combinations thereof. ### Claim 112 (depends on 111) The method of claim 111, wherein the water source in need of treatment comprises fresh water, pond water, sea water, produced water, tower water or a combination thereof, wherein a combination of the water sources is a blended water source that comprises fresh water or pond water and reuse water, and wherein the water source or the peroxycarboxylic acid composition further comprises a friction reducer, a corrosion inhibitor or a viscosity enhancer. ### Claim 113 (depends on 110) The method of claim 110, wherein the water source comprises from about 2 ppm to about 1,000 ppm of said peroxycarboxylic acid composition. ### Claim 114 (depends on 110) The method of claim 110, wherein the C1-C22 percarboxylic acid comprises from about 1 wt-% to about 60 wt-%, the C1-C22 carboxylic acid comprises from about 10 wt-% to about 90 wt-%, and the hydrogen peroxide comprises from about 0.5 wt-% to about 25 wt-% of the percarboxylic acid composition. ### Claim 115 (depends on 110) The method of claim 110, wherein the percarboxylic acid composition is a peroxycarboxylic acid forming composition comprising an ester of polyhydric alcohol and C1-C22 carboxylic acid and hydrogen peroxide, and optionally wherein the ester of polyhydric alcohol and C1-C22 carboxylic acid comprises from about 50 wt-% to about 99 wt-% and the hydrogen peroxide comprises from about 0.1 wt-% to about 50 wt-% of the peroxycarboxylic acid forming composition. ### Claim 116 (depends on 110) The method of claim 110, wherein the pH of the target treated with the peroxycarboxylic acid composition is between about 3 and about 10.5, and wherein the contacting step provides the peroxycarboxylic acid composition to the target by means of a spray, a fog, or a foam, or by dipping all or part of the target in a composition comprising the peroxycarboxylic acid composition, and wherein the contacting step lasts for at least about 1 minute and is conducted at a temperature ranging from about 0° C. to about 130° C. ### Claim 117 (depends on 110) The method of claim 110, wherein the microbial population in and/or on the target is reduced by at least one log10.