Methods for forming peroxyformic acid and uses thereof

Abstract

The present invention relates generally to methods for forming peroxyformic acid, comprising contacting formic acid with hydrogen peroxide. The methods for forming peroxyformic acid can include adding formic acid with a relatively lower concentration of hydrogen peroxide, or adding formic acid to a peroxycarboxylic acid composition or forming composition to react with hydrogen peroxide in the compositions. The present invention also relates to peroxyformic acid formed by the above methods. The present invention further relates to the uses of peroxyformic acid for treating a variety of targets, e.g., target water, including target water used in connection with oil- and gas-field operations. The present invention further relates to methods for reducing or removing H 2 S or iron sulfide in the treated water source, improving clarity of the treated water source, or reducing the total dissolved oxygen or corrosion in the treated water source, using peroxyformic acid, including peroxyformic acid generated in situ.

What is claimed is: 
     
         1 . A method for forming peroxyformic acid comprising:
 contacting formic acid with hydrogen peroxide to form a resulting aqueous composition that comprises a peracid that comprises peroxyformic acid,   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 2 hours of said contacting.   
     
     
         2 . The method of  claim 1 , wherein before the contacting, the formic acid is provided in a composition that comprises formic acid, the composition is an aqueous solution that comprises formic acid, or formic acid is provided in a composition that comprises a substance that generates formic acid upon contact with an aqueous composition. 
     
     
         3 . The method of  claim 1 , wherein before the contacting, the hydrogen peroxide is provided in a composition that comprises hydrogen peroxide, the composition is an aqueous solution that comprises hydrogen peroxide, or the hydrogen peroxide is provided in a composition that comprises a substance that generates hydrogen peroxide upon contact with an aqueous composition. 
     
     
         4 . The method of  claim 1 , wherein (a) the formic acid provided in a first aqueous composition is contacted with the hydrogen peroxide provided in a second aqueous composition to form peroxyformic acid in the resulting aqueous composition, or (b) the formic acid provided in a first aqueous composition is contacted with a substance that generates hydrogen peroxide upon contact with an aqueous composition provided in a second solid composition to form peroxyformic acid in the resulting aqueous composition. 
     
     
         5 . The method of  claim 1 , wherein (a) a substance that generates formic acid upon contact with an aqueous composition provided in a first solid composition is contacted with hydrogen peroxide provided in a second aqueous composition to form peroxyformic acid in the resulting aqueous composition, (b) a substance that generates formic acid upon contact with an aqueous composition provided in a first solid composition and a substance that generates hydrogen peroxide upon contact with an aqueous composition provided in a second solid composition are contacted with a third aqueous composition to form peroxyformic acid in the resulting aqueous composition, or (c) a substance that generates formic acid upon contact with an aqueous composition and a substance that generates hydrogen peroxide upon contact with an aqueous composition are provided in a first solid composition, and the first solid composition is contacted with a second aqueous composition to form peroxyformic acid in the resulting aqueous composition. 
     
     
         6 . The method of  claim 1 , wherein either the first or second composition further comprises a surfactant, enzyme, builder, chelating agent, and/or additional functional ingredient. 
     
     
         7 . The method of  claim 1 , wherein the formed aqueous composition comprises about 5% (w/w) or less hydrogen peroxide. 
     
     
         8 . The method of  claim 1 , wherein the formic acid and hydrogen peroxide are contacted in the presence of a C 2 -C 22  carboxylic acid and the peracid in the formed aqueous composition comprises peroxyformic acid and the C 2 -C 22  percarboxylic acid. 
     
     
         9 . The method of  claim 8 , wherein the C 2 -C 22  carboxylic acid is acetic acid, octanoic acid and/or sulfonated oleic acid, and the peracid in the formed aqueous composition comprises peroxyformic acid and one or more of peroxyacetic acid, peroxyoctanoic acid and peroxysulfonated oleic acid. 
     
     
         10 . The method of  claim 1 , which is conducted at a temperature ranging from about −2° C. to about 70° C. 
     
     
         11 . The method of  claim 1 , which is conducted in the presence of a catalyst. 
     
     
         12 . The method of  claim 1 , wherein before the contacting, the second aqueous composition comprises from about 1 (w/v) to about 40 (w/v) of the C 2 -C 22  percarboxylic acid, the salt of formate or ester of formate is added to the second aqueous composition so that the aqueous composition comprises from about 5 (w/v) to about 30 (w/v) of the salt of formate or ester of formate, and the ratio between the concentration of total peracid (w/w) and the concentration of hydrogen peroxide (w/w) in the resulting aqueous composition reaches about 2 or higher within about 3 hours of the contacting. 
     
     
         13 . The method of  claim 1 , wherein the resulting aqueous composition further comprises a stabilizing agent for the peracid. 
     
     
         14 . The method of  claim 1 , wherein the resulting aqueous composition comprises from about 0.001% to about 20% peroxyformic acid. 
     
     
         15 . Peroxyformic acid composition formed using the method of  claim 1 . 
     
     
         16 . A method for treating a target, which method comprises:
 contacting a target with an effective amount of peroxyformic acid composition of  claim 15  to form a treated target composition,   wherein said treated target composition comprises from about 0.5 ppm to about 5,000 ppm of said peroxyformic acid, and said contacting lasts for sufficient time to stabilize or reduce microbial population in and/or on said target or said treated target composition, and   wherein the target is water, and the method comprises providing an effective amount of the peroxyformic acid composition to the water source in need of treatment to form a treated water source.   
     
     
         17 . The method of  claim 16 , wherein the water is used in a laundry or textile application. 
     
     
         18 . The method of  claim 16 , wherein the peroxyformic acid is used at a concentration from about 0.5 ppm to about 1,000 ppm. 
     
     
         19 . The method of  claim 16 , wherein the contacting step lasts for at least 30 seconds and is conducted at a temperature ranging from about 0° C. to about 70° C. 
     
     
         20 . The method of  claim 16 , wherein the microbial population in and/or on the target or the treated target composition is reduced by at least one log 10 .