Composition and method for inhibiting metal corrosion against acid

Abstract

A method for inhibiting corrosion of a metal article includes contacting the metal article with a corrosive medium containing an acid and a zinc phthalocyanine (Zn-Pc) compound thereby adsorbing the Zn-Pc compound onto at least one surface of the metal article. The Zn-Pc compound is present in the corrosive medium in an amount of 0.01 to 1 millimoles per liter (mmol/L). The Zn-Pc compound is of formula (I).

1 : A method for inhibiting corrosion of a metal article in contact with a corrosive medium, the method comprising:
 contacting the metal article with the corrosive medium comprising an acid and a zinc phthalocyanine (Zn-Pc) compound thereby adsorbing the Zn-Pc compound onto at least one surface of the metal article;   wherein the Zn-Pc compound is present in the corrosive medium in an amount of 0.01 to 1 millimoles per liter (mmol/L);   wherein the Zn-Pc compound has a formula (I)   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , and R 3  are each independently selected from the group consisting of a hydrogen atom, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkoxy, a hydroxyl group, a halogen group, an amine group, a nitro group, and a cyano group. 
       
     
     
         2 : The method of  claim 1 , wherein the metal article is made of aluminum. 
     
     
         3 : The method of  claim 1 , wherein the at least one surface of the metal article is made of aluminum. 
     
     
         4 : The method of  claim 1 , wherein the metal article is part of a casing, a pipe, a pump, a screen, a valve, or a fitting of an oil or a gas well. 
     
     
         5 : The method of  claim 1 , wherein the acid is at least one selected from the group consisting of hydrochloric acid (HCl), sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ), acetic acid, and hydrofluoric acid (HF). 
     
     
         6 : The method of  claim 1 , wherein the contacting the metal article with the corrosive medium is at a temperature of 290 to 340 Kelvin (K). 
     
     
         7 : The method of  claim 1 , wherein the metal article has a corrosion rate of about 50 to 500 millimeter penetration per year (mmpy), when the at least one surface of the metal article is in contact with the corrosive medium at from 298 to 333K, and the Zn-Pc compound is present in the corrosive medium in an amount of from 0.01 to 0.4 mmol/L. 
     
     
         8 : The method of  claim 1 , wherein contacting the Zn-Pc compound provides an inhibition efficiency of 10 to 75% when the at least one surface of the metal article is in contact with the corrosive medium at from 298 to 333K, and the Zn-Pc compound is present in the corrosive medium in an amount of from 0.01 to 0.4 mmol/L. 
     
     
         9 : The method of  claim 1 , wherein the metal article is made of aluminum, and wherein the metal article has an activation energy of 6 to 14 kilojoules per mole (kJ/mol) when the metal article is in contact with the corrosive medium at from 298 to 333K, and the Zn-Pc compound is present in the corrosive medium in an amount of from 0.01 to 0.4 mmol/L. 
     
     
         10 : The method of  claim 1 , wherein the Zn-Pc compound has a ball-type geometry. 
     
     
         11 : The method of  claim 1 , wherein the Zn-Pc compound has a formula (II) 
       
         
           
           
               
               
           
         
       
     
     
         12 : The method of  claim 1 , wherein the Zn-Pc compound absorbed onto the at least one surface of the metal article is present in the form of a film. 
     
     
         13 : The method of  claim 12 , wherein at least 70% of the at least one surface of the metal article is covered by the film of the Zn-Pc compound, each % based on a total surface area of the at least one surface of the metal article. 
     
     
         14 : The method of  claim 1 , wherein the at least one surface of the metal article is made of aluminum, and wherein the at least one surface has a smoother surface morphology compared to a same surface of the metal article in contact with the corrosive medium in the absence of the Zn-Pc compound. 
     
     
         15 : The method of  claim 14 , wherein the at least one surface of the metal article comprises about 0.1 to 1 wt. % carbon, about 0.1 to 1 wt. % nitrogen, about 1 to 4 wt. % oxygen, about 0.1 to 1 wt. % zinc, and about 90 to 99.9 wt. % aluminum, each wt. % based on a total weight of the metal article, as determined by energy dispersive X-ray spectroscopy (EDS). 
     
     
         16 : The method of  claim 15 , wherein the at least one surface of the metal article comprises about 0.53 wt. % carbon, about 0.36 wt. % nitrogen, about 2.19 wt. % oxygen, about 0.52 wt. % zinc, and about 96.41 wt. % aluminum, each wt. % based on the total weight of the metal article, as determined by EDS. 
     
     
         17 : The method of  claim 1 , further comprising preparing the Zn-Pc compound by:
 mixing and heating a nitrophthalonitrile of formula (III), a biphenol of formula (IV) and DMSO in the presence of a base to form a precursor; and   heating the precursor and zinc (II) acetate to form a mixture, and washing;   wherein formula (III) is   
       
         
           
           
               
               
           
         
         wherein formula (IV) is 
       
       
         
           
           
               
               
           
         
       
       and
 wherein R 1 , R 2 , and R 3  are each independently selected from the group consisting of a hydrogen atom, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkoxy, a hydroxyl group, a halogen group, an amine group, a nitro group, and a cyano group. 
 
     
     
         18 : The method of  claim 17 , wherein the nitrophthalonitrile is 3-nitrophthalonitrile. 
     
     
         19 : The method of  claim 17 , wherein the biphenol is 4,4′-dihydroxybiphenyl. 
     
     
         20 : The method of  claim 17 , wherein the base comprises sodium carbonate, and potassium carbonate.