Effective novel non-polymeric and non-fouling additive for inhibiting high-temperature naphthenic acid corrosion and method of using the same

Abstract

The present invention relates to inhibition of high temperature naphthenic acid corrosion occurring in hydrocarbon processing units. The invention provides an effective novel non-polymeric and non-fouling additive for inhibiting high-temperature naphthenic acid corrosion, comprising an effective corrosion-inhibiting amount of a second phosphate ester wherein said second phosphate ester is obtained by reacting a first phosphate ester with an oxirane compound selected from the group consisting of butylene oxide, ethylene oxide, propylene oxide or any other oxirane compound or a combination thereof, preferably with butylene oxide, capably yielding said second phosphate ester, having a structure A or B, wherein Rand Rare each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and Rand Rmay be identical or different, X is H, CHor CH; and n may vary from 1 to 20,wherein said first phosphate ester is having a structure I or II, wherein Rand Rare each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and Rand Rmay be identical or different, said first phosphate ester being obtained as a reaction product of reaction of an alcohol with a phosphorous pentaoxide.