Peroxyformic acid compositions for membrane filtration cleaning in energy services
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.
1. A method for treating a membrane system comprising:
contacting a membrane with a peroxyformic acid composition comprising peroxyformic acid, formic acid, hydrogen peroxide, an acidulant and an anionic surfactant, wherein the composition is membrane compatible and does not damage the membrane as measured by a decrease in flux of the membrane; and
removing biofilm, microbial growth and/or mineral deposits from the membrane surface, wherein the contacting is intermittent and occurs daily, bi-weekly, or weekly.
2. The method of claim 1 , wherein the membrane is a reverse osmosis membrane, nanofiltration membrane, ultrafiltration membrane, or a microfiltration membrane.
3. 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.
4. The method of claim 1 , wherein the peroxyformic acid composition comprises between about 0.001% (w/w) and about 5% (w/w) hydrogen peroxide, and between about 0.0001% (w/w) to about 20% (w/w) peroxyformic acid.
5. 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.
6. The method of claim 1 , wherein the peroxyformic acid composition is free of 2,2-dibromo-3-nitrilopropionamide.
7. The method of claim 1 , wherein the acidulant is nitric acid, sulfuric acid, phosphoric acid, and/or methyl sulfonic acid.
8. The method of claim 1 , wherein the is anionic surfactant is an alkyl aryl sulfonate, alkyl sulfonate, alkyl ether sulfate, alkyl sulfate, and/or alcohol sulfate.
9. The method of claim 8 , wherein the alkyl aryl sulfonate is a linear alkyl benzene sulfonate and/or xylene sulfonate.
10. The method of claim 1 , wherein the membrane is fouled with a hydrocarbon, microorganism, biofilm, mineral scale, and/or iron sulfide.
11. 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.
12. The method of claim 11 , wherein the formic acid is provided in a first aqueous composition and is contacted with a second aqueous solution of the hydrogen peroxide.
13. The method of claim 11 , wherein the method prevents the build-up of microorganisms and/or membrane deposits on the membrane.
14. The method of claim 1 , wherein the peroxyformic acid composition further comprises a wetting agent, a chelant, solvent and/or an additional surfactant.
15. The method of claim 1 , wherein the contacting step lasts between 15 minutes and 15 hours.
16. The method of claim 1 , wherein the peroxyformic acid composition does not generate chlorine species.
17. The method of claim 1 , wherein the membrane is contacted with between about 1 ppm to about 300 ppm actives of peroxyformic acid.
18. The method of claim 1 , wherein the peroxyformic acid composition comprises an additional peroxycarboxylic acid.