There is a formulation and a method for inhibiting carbon-based deposits on metal substrate. The method comprises the use of a formulation comprising at least one oxidizing agent and at least one etchant capable of forming free metal ions from the metal substrate, at least one sequestering agent having a ligand capable of forming a complex with the free metal ions and at least one chelating agent having a ligand capable of complexing with at least one surface metal atom.

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, ##STR00001##
wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and R.sup.1 and R.sup.2 may be identical or different, X is H, CH.sub.3 or C.sub.2H.sub.5; and n may vary from 1 to 20,
wherein said first phosphate ester is having a structure I or II, ##STR00002##
wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and R.sup.1 and R.sup.2 may be identical or different, said first phosphate ester being obtained as a reaction product of reaction of an alcohol with a phosphorous pentaoxide.

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, ##STR00001##
wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and R.sup.1 and R.sup.2 may be identical or different, X is H, CH.sub.3 or C.sub.2H.sub.5; and n may vary from 1 to 20,
wherein said first phosphate ester is having a structure I or II, ##STR00002##
wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of moieties having 1 to 20 carbon atoms and R.sup.1 and R.sup.2 may be identical or different, said first phosphate ester being obtained as a reaction product of reaction of an alcohol with a phosphorous pentaoxide.

A corrosion inhibiting composition is provided which comprises a salt of a fatty acid-amine condensate and an aromatic solvent. The composition can be used in reducing, inhibiting or preventing corrosion of a metal surface used in recovery, transportation, refining or storage of a hydrocarbon fluid containing elemental sulfur or polysulfide.

A corrosion inhibiting composition is provided which comprises a salt of a fatty acid-amine condensate and an aromatic solvent. The composition can be used in reducing, inhibiting or preventing corrosion of a metal surface used in recovery, transportation, refining or storage of a hydrocarbon fluid containing elemental sulfur or polysulfide.

Methods of inhibiting corrosion in a benzene distillation or dryer unit are provided wherein alkenyl succinic acids or anhydrides (ASA) are brought into contact with metal surfaces thereby protecting the metal from an acidic corrosive medium flowing through the overhead. The benzene distillation column or drying tower may be utilized to purify benzene for subsequent feed of the purified benzene to an alkylation process such as in the alkylation of benzene by ethene to form ethylbenzene utilizing a zeolite alkylation catalyst.

Methods of inhibiting corrosion in a benzene distillation or dryer unit are provided wherein alkenyl succinic acids or anhydrides (ASA) are brought into contact with metal surfaces thereby protecting the metal from an acidic corrosive medium flowing through the overhead. The benzene distillation column or drying tower may be utilized to purify benzene for subsequent feed of the purified benzene to an alkylation process such as in the alkylation of benzene by ethene to form ethylbenzene utilizing a zeolite alkylation catalyst.

Disclosed are sulfur-containing molybdenum complexes used in compositions and methods for inhibiting or reducing high temperature corrosion in petroleum refineries.

Disclosed are sulfur-containing molybdenum complexes used in compositions and methods for inhibiting or reducing high temperature corrosion in petroleum refineries.

The invention relates to a composition for inhibiting corrosion of the upper part (or roof) of a pipeline for conveying wet hydrocarbons, i.e. hydrocarbons comprising a variable amount of water, said composition comprising at least one Amine 1 with vapour pressure greater than or equal to 10 mmHg, and at least one. Amine 2 with vapour pressure greater than or equal to 0.1 mmHg and strictly less than 10 mmHg.

The invention also relates to the use of such a composition, and also to the method of inhibiting top-of-line corrosion employing said inhibitor composition.