Metal naphthenate is removed from a crude hydrocarbon mixture by a process. The process includes mixing the crude hydrocarbon mixture comprising metal naphthenate with an acid in the presence of water, wherein the acid converts the metal naphthenate to naphthenic acid and metal salt; allowing the metal salt to partition into a water phase; and separating the crude heavy hydrocarbon mixture comprising naphthenic acid and the water phase comprising the metal salt.

It has been discovered that contaminants such as metals and/or amines can be transferred from a hydrocarbon phase to a water phase in an emulsion breaking process by using a composition that contains water-soluble C5-C12 polyhydroxy carboxylic acids, ammonium salts thereof, alkali metal salts thereof, and mixtures of all of these. The composition may also optionally include a mineral acid to reduce the pH of the desalter wash water. The method permits transfer of metals and/or amines into the aqueous phase with little or no hydrocarbon phase under-carry into the aqueous phase. Resolving the emulsion into the hydrocarbon phase and the aqueous phase occurs in a refinery desalting process using electrostatic coalescence. The composition is particularly useful in treating crude oil emulsions, and in removing calcium and other metals therefrom. The polyhydroxy carboxylic acid additionally inhibits metal corrosion of metal pipe or other equipment used in a crude unit.

Disclosed is a method of removing metals from hydrocarbon oil, comprising: supplying a feed including hydrocarbon oil; mixing the feed with an aqueous solution including a metal scavenger to prepare a first mixture; separating the first mixture into a first aqueous solution phase and a first hydrocarbon phase and discharging the separated first aqueous solution phase; mixing the separated first hydrocarbon phase with washing water to produce a second mixture; separating the second mixture into a second aqueous solution phase and a second hydrocarbon phase; and recovering the separated second hydrocarbon phase and recirculating the separated second aqueous solution phase.

Disclosed is a method of removing metals from hydrocarbon oil, comprising: supplying a feed including hydrocarbon oil; mixing the feed with an aqueous solution including a metal scavenger to prepare a first mixture; separating the first mixture into a first aqueous solution phase and a first hydrocarbon phase and discharging the separated first aqueous solution phase; mixing the separated first hydrocarbon phase with washing water to produce a second mixture; separating the second mixture into a second aqueous solution phase and a second hydrocarbon phase; and recovering the separated second hydrocarbon phase and recirculating the separated second aqueous solution phase.

A method of removing metals and amines from crude oil comprising adding an effective metal removing amount of one or more hydroxycarboxylic acids selected from lactic acid and malic acid and salts thereof to said crude oil; adding wash water to said crude oil; mixing said crude oil, acid and wash water to form an emulsion; and resolving said emulsion into an aqueous phase and crude oil having a reduced metals content.

A method of removing metals and amines from crude oil comprising adding an effective metal removing amount of one or more hydroxycarboxylic acids selected from lactic acid and malic acid and salts thereof to said crude oil; adding wash water to said crude oil; mixing said crude oil, acid and wash water to form an emulsion; and resolving said emulsion into an aqueous phase and crude oil having a reduced metals content.

It has been discovered that metals and/or amines can be removed or transferred from a hydrocarbon phase to a water phase in an emulsion breaking process by using a composition that contains water-soluble hydroxyacids. Suitable water-soluble hydroxyacids include, but are not necessarily limited to glycolic acid, gluconic acid, C.sub.2-C.sub.4 alpha-hydroxy acids, poly-hydroxy carboxylic acids, thioglycolic acid, chloroacetic acid, polymeric forms of the above hydroxyacids, poly-glycolic esters, glycolate ethers, and ammonium salt and alkali metal salts of these hydroxyacids, and mixtures thereof. The composition may also include at least one mineral acid to reduce the pH of the desalter wash water. A solvent may be optionally included in the composition. The invention permits transfer of metals and/or amines into the aqueous phase with little or no hydrocarbon phase undercarry into the aqueous phase. The composition is particularly useful in treating crude oil emulsions, and in removing calcium and other metals therefrom.

It has been discovered that metals and/or amines can be removed or transferred from a hydrocarbon phase to a water phase in an emulsion breaking process by using a composition that contains water-soluble hydroxyacids. Suitable water-soluble hydroxyacids include, but are not necessarily limited to glycolic acid, gluconic acid, C.sub.2-C.sub.4 alpha-hydroxy acids, poly-hydroxy carboxylic acids, thioglycolic acid, chloroacetic acid, polymeric forms of the above hydroxyacids, poly-glycolic esters, glycolate ethers, and ammonium salt and alkali metal salts of these hydroxyacids, and mixtures thereof. The composition may also include at least one mineral acid to reduce the pH of the desalter wash water. A solvent may be optionally included in the composition. The invention permits transfer of metals and/or amines into the aqueous phase with little or no hydrocarbon phase undercarry into the aqueous phase. The composition is particularly useful in treating crude oil emulsions, and in removing calcium and other metals therefrom.

A method comprises correlatingin a system which comprises a non-aqueous phase comprising a hydrocarbon fluid, and an aqueous phasepartitioning levels of a basic contaminant and/or an acid of interest into the aqueous phase with the pH of the aqueous phase. The partitioning levels of the basic contaminant and the acid of interest, as well as the pH of the aqueous phase, are obtained under conditions which are representative of those used in a partitioning process in which a basic contaminant is removed from a hydrocarbon fluid.

The correlations may be used in a method for selecting an acidic environment for use in a partitioning process, for estimating corrosion risk downstream of a partitioning process, or for controlling a partitioning process.

A method comprises correlatingin a system which comprises a non-aqueous phase comprising a hydrocarbon fluid, and an aqueous phasepartitioning levels of a basic contaminant and/or an acid of interest into the aqueous phase with the pH of the aqueous phase. The partitioning levels of the basic contaminant and the acid of interest, as well as the pH of the aqueous phase, are obtained under conditions which are representative of those used in a partitioning process in which a basic contaminant is removed from a hydrocarbon fluid.

The correlations may be used in a method for selecting an acidic environment for use in a partitioning process, for estimating corrosion risk downstream of a partitioning process, or for controlling a partitioning process.