Simultaneous metal, sulfur and nitrogen removal using supercritical water

Abstract

A process for removing metals, sulfur and nitrogen in the upgrading of hydrocarbons comprising: mixing hydrocarbons containing metals, sulfur and nitrogen with a fluid comprising water that has been heated to a temperature higher than its critical temperature in a mixing zone to form a mixture; passing the mixture to a reaction zone; reacting the mixture in the reaction zone under supercritical water conditions in the absence of externally added hydrogen for a residence time sufficient to allow upgrading reactions to occur while maintaining an effective amount of metals, derived from the hydrocarbon undergoing upgrading, in the reaction zone to catalyze the upgrading reactions; and recovering upgraded hydrocarbons having a lower concentration of metals, sulfur and nitrogen than the hydrocarbons before reaction is disclosed.

1 . A process for removing metals, sulfur and nitrogen in the upgrading of hydrocarbons comprising:
 (a) mixing hydrocarbons containing metals, sulfur and nitrogen with a fluid comprising water that has been heated to a temperature higher than its critical temperature in a mixing zone to form a mixture;   (b) passing the mixture to a reaction zone;   (c) reacting the mixture in the reaction zone under supercritical water conditions in the absence of externally added hydrogen for a residence time sufficient to allow upgrading reactions to occur while maintaining an effective amount of metals, derived from the hydrocarbon undergoing upgrading, in the reaction zone to catalyze the upgrading reactions; and   (d) recovering upgraded hydrocarbons having a lower concentration of metals, sulfur and nitrogen than the hydrocarbons of step (a).   
   
   
       2 . A process according to  claim 1 , wherein the hydrocarbons are heavy hydrocarbons selected from the group consisting of whole heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon fractions obtained from crude petroleum oils, heavy vacuum gas oils, vacuum residuum, petroleum tar, coal tar and their mixtures. 
   
   
       3 . A process according to  claim 1 , wherein the fluid comprising water enters the mixing zone at a temperature sufficiently higher than the critical temperature of water so as to cause the resulting mixture to have a temperature higher than the critical temperature of water. 
   
   
       4 . A process according to  claim 3 , wherein the temperature of the fluid comprising water is from 400° C. to 600° C. 
   
   
       5 . A process according to  claim 1 , wherein the hydrocarbons in step (a) are at a temperature of from 100° C. to 200° C. 
   
   
       6 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 1000° C., a pressure from 3,205 psia to 10,000 psia an oil/water volume ratio from 1:0.1 to 1:5 and where the residence time is from 1 minute to 6 hours. 
   
   
       7 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 600° C., a pressure from 3,205 psia to 7,200 psia, an oil/water volume ratio from 1:0.5 to 1:3 and where the residence time is from 8 minutes to 2 hours. 
   
   
       8 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 400° C. a pressure from 3,205 psia to 4,000 psia, an oil/water volume ratio from 1:1 to 1:2 and where the residence time is from 10 to 40 minutes. 
   
   
       9 . A process according to  claim 1 , wherein the mixture in the reaction zone is reacted in the absence of any externally supplied catalyst or promoter. 
   
   
       10 . A process according to  claim 1 , further comprising the step of heating the mixture formed in step (a) to a temperature higher than the supercritical temperature of water before passing the mixture to the reaction zone. 
   
   
       11 . A process for removing metals and sulfur in the upgrading of hydrocarbons comprising:
 (a) mixing hydrocarbons containing metals and sulfur with a fluid comprising water having a temperature higher than the critical temperature of water in a mixing zone to form a mixture having a temperature higher than the critical temperature of water;   (b) passing the mixture to a reaction zone;   (c) reacting the mixture in the reaction zone under supercritical water conditions in the absence of externally added hydrogen for a residence time sufficient to allow upgrading reactions including demetalation and desulfurization to occur while maintaining an effective amount of metals, derived from the hydrocarbon undergoing upgrading, in the reaction zone to catalyze desulfurization reactions; and   (d) recovering upgraded hydrocarbons having a lower concentration of metals and sulfur than the hydrocarbons of step (a)   
   
   
       12 . A process according to  claim 11 , wherein the hydrocarbons are heavy hydrocarbons selected from the group consisting of whole heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon fractions obtained from crude petroleum oils, heavy vacuum gas oils, vacuum residuum, petroleum tar, coal tar and their mixtures 
   
   
       13 . A process according to  claim 11 , wherein the fluid comprising water enters the mixing zone at a temperature sufficiently higher than the critical temperature of water so as to cause the resulting mixture to have a temperature higher than the critical temperature of water. 
   
   
       14 . A process according to  claim 13 , wherein the temperature of the fluid comprising water is from 400° C. to 600° C. 
   
   
       15 . A process according to  claim 11 , wherein the heavy hydrocarbons in step (a) are at a temperature of from 100° C. to 200° C. 
   
   
       16 . A process according to  claim 10 , wherein the supercritical water conditions include a temperature from 374° C. to 1000° C., a pressure from 3,205 psia to 10,000 psia an oil/water volume ratio from 1:0.1 to 1:5 and where the residence time is from 1 minute to 6 hours. 
   
   
       17 . A process according to  claim 10 , wherein the supercritical water conditions include a temperature from 374° C. to 600° C., a pressure from 3,205 psia to 7,200 psia, an oil/water volume ratio from 1:0.5 to 1:3 and where the residence time is from 8 minutes to 2 hours. 
   
   
       18 . A process according to  claim 10 , wherein the supercritical water conditions include a temperature from 374° C. to 400° C., a pressure from 3,205 psia to 4,000 psia, an oil/water volume ratio from 1:1 to 1:2 and where the residence time is from 10 to 40 minutes. 
   
   
       19 . A process according to  claim 10 , further comprising the step of heating the mixture formed in step (a) to a temperature higher than the critical temperature of water before passing the mixture to the reaction zone. 
   
   
       20 . A process for removing metals and sulfur in the upgrading of hydrocarbons comprising:
 (a) mixing hydrocarbons containing metals and sulfur with a fluid comprising water that has been heated to a temperature higher than its critical temperature in a mixing zone to form a mixture;   (b) passing the mixture to a reaction zone;   (c) reacting the mixture in the reaction zone under supercritical water conditions in the absence of externally added hydrogen for a residence time sufficient to allow upgrading reactions including demetalation and desulfurization to occur while maintaining an effective amount of metals, derived from the hydrocarbon undergoing upgrading, in the reaction zone to catalyze desulfurization reactions;   (d) separating a dreg stream containing metals from the reaction product;   (e) passing at least a portion of the dreg stream to the reaction zone; and   (g) recovering upgraded hydrocarbons having a lower concentration of metals and sulfur than the hydrocarbons of step (a).