Patent ID: 8323416

Claim:
A process for removing one or more scale deposits formed on a surface, comprising the steps of: providing a composition having a first pH of less than about 7.5 to prevent polythionic acid stress corrosion cracking to said surface, said composition comprising: a) an effective amount of an organic acid and/or a salt thereof; and b) an effective amount of an oxidizing agent selected from the group consisting of a peroxide, a chlorate, a perchlorate, a nitrate, or a permanganate, wherein the organic acid and/or the salt thereof and the oxidizing agent in the composition are in a weight ratio of about 2.5:1 to about 1:10; providing scale deposits comprising primarily metal sulfides and coke formed on said surface, wherein said scale deposits are formed in a hydrocarbon conversion process; contacting the surface with said composition for a period of time sufficient to remove one or more scale deposits, wherein during said contacting step, the composition has a second pH, said second pH being greater than the first pH.