Low corrosion alkane sulfonic acids for condensation reactions

Abstract

The present invention relates to methods for adding an aqueous solution of alkane sulfonic acids to a reactor via a pipe or container, wherein a condensation reaction takes place after addition of the aqueous solution of alkane sulfonic acid and to methods for reducing or limiting corrosion by adding said aqueous solution to a reactor. The present invention also relates to the use of aqueous solutions of alkane sulfonic acids in the reduction or limitation of corrosion and to the use of such aqueous solutions in condensation reactions.

1 - 19 . (canceled) 
     
     
         20 . A method for reducing the corrosion rate of an iron-containing surface, comprising adding an aqueous solution (A) to the iron-containing surface,
 wherein said aqueous solution (A) comprises 80 w/w % to 99 w/w % of an alkane sulfonic acid, relative to the total weight of the aqueous solution (A).   
     
     
         21 . The method of  claim 20 , wherein the alkane sulfonic acid is methane sulfonic acid. 
     
     
         22 . The method of  claim 20 , wherein the surface comprising iron further comprises chrome and/or nickel. 
     
     
         23 . The method of  claim 20 , wherein the aqueous solution (A) further comprises nitric acid or salts thereof. 
     
     
         24 . The method of  claim 20 , wherein the iron-containing surface belongs to a reactor, pipe and/or container. 
     
     
         25 . The method of  claim 24 , wherein an acid catalyzed reaction takes place in the reactor after the addition of the aqueous solution (A) into the reactor. 
     
     
         26 . The method of  claim 25 , wherein the reaction is a condensation reaction. 
     
     
         27 . The method of  claim 20 , wherein a temperature of the aqueous solution (A) is at least about 20° C. when contacted with the iron-containing surface. 
     
     
         28 . The method of  claim 20 , wherein the method limits the corrosion rate of an iron-containing surface to a rate of max. 0.3 mm/year.