Non-triazole imidazoline and amide compounds and methods for inhibiting corrosion in industrial water treatment

Abstract

Methods of treating aqueous systems with treatment compositions including non-triazole derivatives of imidazoline and/or amide compounds are provided that are effective to inhibit corrosion of corrodible metal surfaces in the aqueous systems. The non-triazole imidazoline and/or amide compounds show comparable or better corrosion inhibition as compared to conventional triazole corrosion inhibitors, and have low toxicity and good stability in the presence of halogens such as halogen-containing biocides or free chlorine.

What is claimed is: 
     
         1 . A method of inhibiting corrosion of a corrodible metal surface that contacts a water stream in a water system, the method comprising:
 introducing into the water stream a treatment composition including at least one of (i) at least one non-triazole derivative of imidazoline compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group, and (ii) at least one amide compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group.   
     
     
         2 . The method of  claim 1 , wherein the treatment composition includes the non-triazole derivative of imidazoline compound, and the non-triazole derivative has a structure corresponding to Formula (I): 
       
         
           
           
               
               
           
         
         where R is a hydrocarbon group having in a range of 7 to 20 carbon atoms. 
       
     
     
         3 . The method of  claim 2 , wherein the hydrocarbon group has in a range of 11 to 20 carbon atoms. 
     
     
         4 . The method of  claim 1 , wherein the treatment composition includes the amide compound, and the amide compound has a structure corresponding to Formula (II): 
       
         
           
           
               
               
           
         
         where R is a hydrocarbon group having 7 to 20 carbon atoms, each R′ is independently H or C, R″ is N, a nitrogen-containing group, O, C, OH, or COOH, n is in a range of 1 to 20, m is in a range of 1 to 20, and 1 is in a range of 1 to 20. 
       
     
     
         5 . The method of  claim 4 , wherein R has 11 to 20 carbon atoms. 
     
     
         6 . The method of  claim 1 , wherein a number of the at least two nitrogen atoms is in a range of 2 to 4. 
     
     
         7 . The method of  claim 1 , wherein the at least one carboxylate group of the non-triazole derivative is a carboxylate ether, and wherein the at least one carboxylate group of the amide compound is a carboxylate ether. 
     
     
         8 . The method of  claim 1 , wherein the treatment composition includes the non-triazole derivative of imidazoline compound, and the non-triazole derivative is sodium dicarboxylethyl coco phosphoethyl imidazoline. 
     
     
         9 . The method of  claim 1 , wherein the treatment composition includes the amide compound, and the amide compound is selected from the group consisting of disodium cocoamphodiacetate, sodium cocoamphoacetate, and disodium lauroamphodiacetate. 
     
     
         10 . The method of  claim 1 , wherein the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is introduced into the water stream in an amount of from 0.01 ppm to 100 ppm. 
     
     
         11 . The method of  claim 1 , wherein the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is introduced into the water stream in an amount of from 1 ppm to 3 ppm. 
     
     
         12 . The method of  claim 1 , wherein the corrodible metal surface is a yellow metal surface. 
     
     
         13 . The method of  claim 1 , wherein the water system is a mixed metal system including a yellow metal surface and at least one of a stainless steel surface, mild steel surface, galvanized steel surface, a ferrous steel surface, and an aluminum surface. 
     
     
         14 . The method of  claim 1 , further comprising introducing into the water stream at least one polyol in an amount of from 0.01 ppm to 10 ppm. 
     
     
         15 . The method of  claim 14 , wherein the polyol is a carbohydrate derived polyol. 
     
     
         16 . The method of  claim 1 , further comprising introducing into the water stream at least one compound selected from the group consisting of glucaric acid, gluconic acid, glucoheptonate, citric/poly citric acid, ascorbic acid, erythorbic acid, glycolic acid, adipic acid, and polymaleic acid in a total amount of from 0.01 ppm to 10 ppm. 
     
     
         17 . The method of  claim 1 , further comprising introducing into the water stream at least one of a nitrite, molybdate, silicate, borate, Sn, Al, Zn, PO 4 , polymaleic acid, and organic phosphonate compound in an amount of from 0.01 ppm to 100 ppm. 
     
     
         18 . The method of  claim 1 , wherein the treatment composition includes the at least one amide compound, and the method further comprises introducing into the water stream at least one chelant selected from the group consisting of glutamic acid, N,N-diacetic acid, tetrasodium salt (GLDA), methylglycine N,N-Diacetic Trisodium Salt (MGDA), and ethanoldiglycinic disodium salt (EDG). 
     
     
         19 . The method of  claim 1 , wherein the water stream includes less than 5 ppm triazole compounds. 
     
     
         20 . The method of  claim 1 , wherein the treatment composition exhibits a chlorine demand in the water stream of 1.1 mg/L or less. 
     
     
         21 . The method of  claim 1 , wherein a sufficient amount of the treatment composition is introduced into the water stream for a sufficient duration to form a protective film on the corrodible metal surface that has a thickness in a range of 1 nm to 150 nm. 
     
     
         22 . The method of  claim 1 , wherein a sufficient amount of the treatment composition is introduced into the water stream for a sufficient duration so that the corrodible metal surface has a protective film and exhibits a contact angle that is in a range of from 65 to 85 degrees.