Patent ID: 7381319

Claim:
A method for inhibiting corrosion of metal surfaces in an overhead system in which hydrocarbons, water, ammonium chloride or amine hydrochlorides condense, the method comprising adding to the overhead system an amine composition in an amount and at a rate sufficient to maintain the pH of water condensate in the system at a pH of about 4.0 or higher effective to inhibit corrosion, the amine composition comprising: one sole amine selected from the group consisting of tert-butylamine, ethyldimethylamine, and isopropyldimethylamine; or at least two different amines selected from the group consisting of dimethylethanolamine, n-butylamine, sec-butylamine, tert-butylamine, diethylamine, dimethylbutylamine, dimethylisopropanolamine, ethylamine, ethyldimethylamine, N-ethylmorpho-line, isopropylamine, isopropyldimethylamine, methylamine, and trimethylamine.