Method and device for electrostatic desalter optimization for enhanced metal and amine removal from crude oil

Abstract

A method for removing calcium, iron, other metals, and amines from crude oil in a refinery desalting process includes the steps of: running a plurality of tests to determine at least one statistically significant processing characteristic of the refinery desalting process; adding a wash water to the crude oil; adding the wash water to the crude oil to create an emulsion; adding to the wash water, the crude oil or the emulsion an acid additive consisting of at least one of the following: oxalic acid, citric acid, water-soluble hydroxyacid selected from the group consisting of glycolic acid, gluconic acid, C.sub.2-C.sub.4 alpha-hydroxy acids, malic acid, lactic acid, 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; resolving the emulsion containing the acid additive into a hydrocarbon phase and an aqueous phase; and adjusting a control setting of the processing characteristic as a function of the tests.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a method and device for determining the statistically optimal desalter parameter settings for removing metals, amines and other contaminants from crude oil at minimum cost via electrostatic coalescence.BACKGROUND INFORMATION[0002]U.S. Pat. No. 4,853,109 discloses a method for removing metal contaminants, particularly iron and non-porphyrin, organically-bound iron components from crude petroleum. This process comprises mixing crude oil with an aqueous solution of hydroxo-carboxylic acids or salts thereof, preferably citric acid, and separating the aqueous solution and metals from the crude.[0003]U.S. Pat. No. 5,078,858 discloses a method for extracting iron species from crude oil by directly adding oxalic or citric acid to the crude oil feedstock, mixing the acid and oil, then adding wash water to form a water in oil emulsion. The emulsion is resolved separating the aqueous solution and metals from the crude.[0004]U.S. Pat....

AI Technical Summary

Problems solved by technology

First, as temperature is increased, there is a corresponding decrease in oil density and viscosity which implies a significant increase in the settling rate of water droplets within the oil phase thus allowing a greater amount of oil to be processed resulting in an increase in profit from performing oil desalting.

However, crude oil conductivity increases exponentially with temperature which implies a higher rate of electrical power consumption during electrostatic coalescence which increases processing expense.

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