# US 11,026,420 B2 · Peroxyformic acid compositions for membrane filtration cleaning in energy services > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,026,420 B2 - Document ID: US11026420B2 - Status: Granted - Kind: B2 - Application number: 16/559,894 - Filed: 2019-09-04 - Published: 2020-01-02 - Granted: 2021-06-08 - Earliest claimed: 2016-12-15 - Assignees: Ecolab USA Inc. - Applicants: Ecolab USA Inc. - Inventors: Junzhong Li; Cynthia Bunders; Richard Staub; Paul Frazer Schacht; Caleb Power; Ramakrishnan Balasubramanian; Robert J. Ryther; Catherine Hanson - Web page: https://patentgrep.com/patent/US11026420B2 ## CPC - A01N 37/16: containing the group [IMAGE cpc-sch-A01N-0934.gif]; Thio analogues thereof - A61L 2/18: Liquid substances - A61L 2/186: Peroxide solutions - A61L 2202/17: Combination with washing or cleaning means - C02F 2303/20: Prevention of biofouling - A01N: PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF (preservation of food or foodstuff A23); BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES (preparations for medical, dental or toiletry purposes which kill or prevent the growth or proliferation of unwanted organisms A61K); PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - 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 Peroxyformic acid compositions for treatment and removal of biofilm growth and mineral deposits on membranes for energy services applications are disclosed. In particular, peroxyformic acid compositions are generated in situ or on site generation for the reduction and prevention, of biofilms and the mitigation of mineral buildup on the membranes. The compositions according to the invention are compatible with the membranes under application of use conditions. ## Claims ### Claim 1 A method for removing mineral deposits from a membrane system comprising: contacting a membrane fouled with mineral deposits comprising sulfate, sulfur, and/or sulfide with a peroxyformic acid composition comprising peroxyformic acid and hydrogen peroxide, wherein the ratio of the peroxyformic acid to the hydrogen peroxide in the peroxyformic acid composition is from about 5:1 to about 40:1; and removing the mineral deposits from the membrane; wherein the contacting occurs not more frequently than once every 24 hours, and wherein the peroxyformic acid composition contacts the membrane for less than about 12 hours; and wherein the peroxyformic acid composition is membrane compatible and does not damage the membrane as measured by a decrease in flux of the membrane. ### Claim 2 (depends on 1) The method of claim 1, wherein the membrane is a reverse osmosis membrane, nanofiltration membrane, ultrafiltration membrane, or a microfiltration membrane. ### Claim 3 (depends on 1) The method of claim 1, wherein the membrane comprises cellulose, cellulose acetate, nitrocellulose, polysulfone, polyethersulfone, fully aromatic polyamide, polyvinylidene fluoride, polytetrafluoroethylene, polyacrylnitrile, polypropylene, carbon, alpha-aluminum oxide, zirconium oxide, ceramic and/or stainless steel. ### Claim 4 (depends on 1) The method of claim 1, wherein the treatment with the peroxyformic acid composition does not negatively impact the pressure on the membrane or decrease the lifespan of the membrane in comparison to a membrane treated with other oxidizer chemistries. ### Claim 5 (depends on 1) The method of claim 1, wherein the membrane system treats a water source. ### Claim 6 (depends on 5) The method of claim 5, wherein the water source is freshwater, sea water, produced water, brackish water, transport water, and/or water used in oil and gas production systems. ### Claim 7 (depends on 5) The method of claim 5, wherein the mineral deposits comprise calcium sulfate, barium sulfate, strontium sulfate, and/or iron sulfide. ### Claim 8 (depends on 1) The method of claim 1, wherein the treatment with the peroxyformic acid composition further removes microorganisms from the membrane system. ### Claim 9 (depends on 8) The method of claim 8, wherein the microorganisms comprise sulfur- and/or sulfate-reducing bacteria. ### Claim 10 (depends on 1) The method of claim 1, wherein the concentration of hydrogen peroxide in the peroxyformic acid composition is between about 0.001% (w/w) to about 5% (w/w). ### Claim 11 (depends on 1) The method of claim 1, further comprising at least one additional step of a first product removal step before the membrane is contacted with the peroxyformic acid composition, a pre-rinse step of washing the membrane with water, a soak step of washing the membrane, and/or an additional treatment cycle(s) comprising an acidic treatment, an enzymatic treatment, an alkaline treatment and/or a neutral treatment either before or after the peroxyformic acid composition contacts the membrane. ### Claim 12 (depends on 1) The method of claim 1, wherein the membrane is contacted with from about 0.00001% (w/w) to about 0.1% (w/w) active peroxyformic acid. ### Claim 13 (depends on 1) The method of claim 1, wherein the membrane is contacted with peroxyformic acid for at least 15 minutes. ### Claim 14 (depends on 1) The method of claim 1, wherein the membrane is contacted with an additional peroxyacid, chelant, solvent, surfactant and/or other additive which may be dosed separately or simultaneously with the peroxyformic acid composition. ### Claim 15 (depends on 1) The method of claim 1, wherein the membrane is contacted with the peroxyformic acid composition at a temperature of from about 2° C. to about 70° C. ### Claim 16 (depends on 1) The method of claim 1, wherein the peroxyformic acid composition is generated in situ by contacting formic acid with hydrogen peroxide, wherein before said contacting, the ratio between the concentration of said formic acid (w/v) and the concentration of said hydrogen peroxide (w/v) is about 2 or higher, and the ratio between the concentration of said peracid (w/w) and the concentration of hydrogen peroxide (w/w) in said formed resulting aqueous composition reaches about 2 or higher within about 1 hour of said contacting. ### Claim 17 (depends on 1) The method of claim 1, further comprising a step of reducing the concentration of the hydrogen peroxide in the peroxyformic acid composition. ### Claim 18 (depends on 1) The method of claim 1, wherein contacting step includes contacting the membrane with at least about 1 ppm to about 300 ppm actives of peroxyformic acid composition.