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.

1 . A method for removing calcium, iron, other metals, and amines from crude oil in a refinery desalting process comprising 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.   
     
     
         2 . The method as recited in  claim 1  wherein the pH of the wash water, if the hydroxyacid is added to the wash water, is below 6. 
     
     
         3 . The method as recited in  claim 1  wherein different control settings are stored for different types of crude oil. 
     
     
         4 . The method as recited in  claim 1  wherein the tests include a plurality of candidate variables representing different processing characteristics. 
     
     
         5 . The method as recited in  claim 4  wherein the tests include setting minimum and maximum values for the candidate variables. 
     
     
         6 . The method as recited in  claim 1  wherein the hydroxyacid selected is malic acid. 
     
     
         7 . The method as recited in  claim 1  wherein the processing characteristic is a temperature of the crude oil or wash water. 
     
     
         8 . The method as recited in  claim 1  wherein the processing characteristic is a crude oil supply feed rate. 
     
     
         9 . The method as recited in  claim 1  wherein the processing characteristic is a temperature of the emulsion. 
     
     
         10 . The method as recited in  claim 1  wherein the processing characteristic is a percentage of hydroxyacid additive to the wash water. 
     
     
         11 . The method as recited in  claim 1  wherein the processing characteristic is a flow rate of a solution mixture of hydroxyacid additive and wash water. 
     
     
         12 . The method as recited in  claim 1  wherein the processing characteristic is an electrostatic desalter electric field. 
     
     
         13 . The method as recited in  claim 1  wherein the processing characteristic is an electrostatic desalter water or emulation level. 
     
     
         14 . The method as recited in  claim 1  further comprising determining a prediction equation as a function of the tests. 
     
     
         15 . The method as recited in  claim 4  wherein a mean square function determination is made for each candidate variable. 
     
     
         16 . A method for improving a refinery desalting process comprising the steps of:
 providing a range of values for at least one candidate variable representing a desalting process characteristic;   performing a statistical calculation to determine at least one statistically significant candidate variable of the at least one candidate variable which is statistically significant for improving the refinery desalting process; and   adjusting a control setting of the desalting process as a function of the statistical calculation.   
     
     
         17 . The method as recited in  claim 16  wherein the range of values includes a minimum value and a maximum value. 
     
     
         18 . The method as recited in  claim 16  wherein the at least one candidate variable includes a plurality of candidate values. 
     
     
         19 . A crude oil refinery, crude oil desalter, or laboratory environment operating the method as recited in  claim 1 . 
     
     
         20 . A crude oil refinery, crude oil desalter, or laboratory environment operating the method as recited in  claim 16 .