Described herein are methods and systems for performing liquid-liquid extraction in bulk tankage. According to certain embodiments, the liquid-liquid extraction can occur in a bulk tank via a circulation loop, in which a solvent mixture is injected with the hydrocarbon ahead of mix valves on the circulation loop. According to other embodiments, a misting system is installed in the vapor or head space of bulk tankage. The misting system distributes small micro-drops of a solvent mixture so as to cause a uniform lay down over the entire top surface area of hydrocarbon. The solvent mixture migrates from the top surface of the hydrocarbon to the bottom of the bulk tank, reacting during migration to cause liquid-liquid extraction.

Methods for conserving the use of fresh wash water in crude oil desalting are described. A crude oil stream including salt mixes with a wash water stream to form an emulsion. The emulsion flows to a desalter, and the wash water coalesces to reform the wash water stream and to transfer at least a portion of the salt from the crude oil stream to the wash water stream. The crude oil stream with reduced salt content separates from the wash water stream. The effluent, which includes the wash water stream, flows from the desalter to a processing unit. The effluent is processed to reduce a concentration of salt in the effluent to be substantially equal to or less than a concentration of salt in the wash water stream. At least a portion of the processed effluent mixes with the crude oil stream before the emulsion flows to the desalter.

A method for selective extraction of naphthenic acids from an acidic crude oil, including: providing an acidic crude oil including naphthenic acids and having a total acid number (TAN) greater than 0.4; mixing the acidic crude oil with a first aqueous solution including water and a weak base to extract a portion of naphthenic acids from the acidic crude oil thereby creating a second aqueous solution containing a mixture of the portion of naphthenic acids, the water and the weak base in an emulsion; separating the second aqueous solution from the emulsion; wherein the second aqueous solution contains an additional portion of the acidic crude oil; adding a salt to the second aqueous solution, thereby causing the additional portion of the acidic crude oil to separate from the second aqueous solution; removing the additional portion of the acidic crude oil from the second aqueous solution; and extracting the portion of the naphthenic acids from the second aqueous solution.

A process for treating a heavy oil by heating a feedstock comprising a heavy oil in order to separate from the heavy oil a first fraction. The first fraction contains no more than 25% of the total number of acid groups of the heavy oil. A second fraction contains at least 75% of the total number of acid groups of the heavy oil. The second fraction then is treated under conditions that provide a heavy oil that has a total acid number, or TAN, that does not exceed 1.0 mg KOH/g, or is at least 50% lower than the total acid number prior to treatment, an olefin content that does not exceed 1.0 wt. %, and a p-value of at least 50% of the p-value of the heavy oil prior to treatment, or a p-value that is at least 1.5.

A method and apparatus for continuously treating acid gases including recovering absorbent chemicals by introducing streams leaving a regenerator and/or leaving an absorber into a static mixing zone wherein supplemental washing water is added to recover absorbent chemicals. Improvements to the prior art methods are provided where one or more absorbent chemical recovery units are included to increase the amount of recovered absorbent chemicals exiting the regenerator and/or exiting the absorber are increased and/or maximized. Absorbent chemical recovery units can include mixing units where liquid is added to the stream of sour gas and absorbent chemical to mix with and absorb the absorbent chemical from the stream.

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.

The present invention relates to the field of inhibition of metal corrosion in hot acidic hydrocarbons, wherein acidity is derived from presence of naphthenic acid. More particularly, it relates to a polymeric additive for inhibiting high temperature napthenic acid corrosion, wherein said polymeric additive is polymeric phosphate ester of polyisobutylene succinate ester or oxide derivative of polymeric phosphate ester of polyisobutylene succinate ester. A polymeric phosphate ester of polyisobutylene succinate ester which is capable of acting as naphthenic acid corrosion inhibitor by inhibiting naphthenic acid corrosion in crude oil/feedstock/hydrocarbon streams containing naphthenic acid, and demonstrating higher thermal stability at elevated temperature varying from about 200 C. to about 400 C. [about 400 F. to about 750 F.] is disclosed.

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.

Methods for conserving the use of fresh wash water in crude oil desalting are described. A crude oil stream including salt mixes with a wash water stream to form an emulsion. The emulsion flows to a desalter, and the wash water coalesces to reform the wash water stream and to transfer at least a portion of the salt from the crude oil stream to the wash water stream. The crude oil stream with reduced salt content separates from the wash water stream. The effluent, which includes the wash water stream, flows from the desalter to a processing unit. The effluent is processed to reduce a concentration of salt in the effluent to be substantially equal to or less than a concentration of salt in the wash water stream. At least a portion of the processed effluent mixes with the crude oil stream before the emulsion flows to the desalter.

The present disclosure refers to a process and a process plant for extraction of metals from a hydrocarbon mixture obtained from a gasification or pyrolysis process, comprising the steps of combining said hydrocarbon mixture with an aqueous acid forming a mixture, mixing said mixture, separating said mixture in a contaminated aqueous phase and a purified hydrocarbon phase, with the associated benefit of said aqueous acid being able to release metals bound in such gasification and pyrolysis processes.