Systems and methods to enhance heavy metals removal from liquid hydrocarbons

Abstract

The inventions relate generally to systems and methods for removing mercury or mercury containing compound(s) from hydrocarbon solutions.

What is claimed is: 
     
         1 . A system for removing mercury from a hydrocarbon mixture with an initial level of mercury of more than about 100 ppb comprising:
 one or more tanks;   one or more chemical additives for promoting a chemical reaction within the hydrocarbon mixture and forming a top layer comprising crude oil with a reduced mercury content relative to the initial level of mercury in the hydrocarbon mixture and a bottom layer comprising water and mercury; and   a separator for separating the top layer from the bottom layer.   
     
     
         2 . The system of  claim 1 , wherein, said separator is selected from a bulk separator, a desalter separator, a sedimentation tank, a centrifuge, a filter, a flotation tank, and an inlet separator. 
     
     
         3 . The system of  claim 1 , wherein the one or more tanks include a tank for the top layer and a tank for the bottom layer. 
     
     
         4 . The system of  claim 1 , wherein the chemical additives are selected from 6-mercapto-1-hexanol, thiosalicyclic acid/4-mercaptobenzoic acid, pentaerythritol tetrakis(3-mercaptopropionate), cysteine, triethylene glycol, terephthalic acid, and mixtures thereof. 
     
     
         5 . The system of  claim 1 , wherein the one or more chemical additives are selected from 2,2′-thiodiethanethiol, ethylene glycol bis-mercaptoacetate, 6-mercapto-1-hexanol, cysteine, 4-mercaptobenzoic acid, 2-Mercaptobenzothiazole, triethylene glycol, terephthalic acid, and mixtures thereof. 
     
     
         6 . The system of  claim 1 , wherein the one or more chemical additives further comprise water and wherein the one or more chemical additives are present in the water in a range of from about 10 ppm to about 1000 ppm. 
     
     
         7 . The system of  claim 1 , further comprising a mixer for mixing the hydrocarbon mixture with the one or more chemical additives. 
     
     
         8 . The system of  claim 1 , wherein the separator comprises a 0.2-10 micron nominal filter. 
     
     
         9 . A method for separating mercury from a mixture comprising one or more hydrocarbons and an initial level of mercury, wherein the method comprises:
 introducing one or more chemical additives into the mixture to promote a chemical reaction and form a top layer comprising crude oil with a reduced mercury content relative to the initial level of mercury in the hydrocarbon mixture and a bottom layer comprising water and mercury; and   separating the top layer from the bottom layer.   
     
     
         10 . The method of  claim 9 , wherein the separating step comprises employing a bulk separator, a desalter separator, a sedimentation tank, a centrifuge, a filter, a flotation tank, or an inlet separator. 
     
     
         11 . The method of  claim 9 , wherein the one or more chemical additives are introduced into an injection port at a wellhead into the mixture comprising one or more hydrocarbons. 
     
     
         12 . The method of  claim 9 , wherein the one or more chemical additives are selected from 6-mercapto-1-hexanol, thiosalicyclic acid/4-mercaptobenzoic acid, pentaerythritol tetrakis(3-mercaptopropionate), cysteine, a glycol, an organic acid, triethylene glycol, terephthalic acid, and mixtures thereof. 
     
     
         13 . The method of  claim 12  wherein the glycol is triethylene glycol. 
     
     
         14 . The method of  claim 12  wherein the organic acid is terephthalic acid. 
     
     
         15 . The method of  claim 9 , wherein the one or more chemical additives are selected from 2,2′-thiodiethanethiol, ethylene glycol bis-mercaptoacetate, 6-mercapto-1-hexanol, cysteine, 4-mercaptobenzoic acid, 2-Mercaptobenzothiazole, and mixtures thereof. 
     
     
         16 . The method of  claim 9 , wherein the one or more hydrocarbons comprise crude oil. 
     
     
         17 . The method of  claim 9 , wherein the separating step comprises employing a 0.45 micron filter. 
     
     
         18 . The method of  claim 9 , wherein the method is performed in one more tanks selected from a ship cargo tank, an FSO cargo tank, or an OCP tank. 
     
     
         19 . The method of  claim 9 , wherein the facilitating comprises mixing with a desalter mixer or a pump recirculator. 
     
     
         20 . The method of  claim 9 , wherein the one or more chemical additives are added with water to the hydrocarbons.