Supercritical Water Separation Process

Patent metadata

Field	Value
Publication number	US-2018010057-A1
Application number	US-201715644143-A
Country	US
Kind code	A1
Filing date	Jul 7, 2017
Priority date	Jul 8, 2016
Publication date	Jan 11, 2018
Grant date	—

Abstract

A supercritical water separation process and system is disclosed for the removal of metals, minerals, particulate, asphaltenes, and resins from a contaminated organic material. The present invention takes advantage of the physical and chemical properties of supercritical water to effect the desired separation of contaminants from organic materials and permit scale-up. At a temperature and pressure above the critical point of water (374° C., 22.1 MPa), nonpolar organic compounds become miscible in supercritical water (SCW) and polar compounds and asphaltenes become immiscible. The process and system disclosed continuously separates immiscible contaminants and solids from the supercritical water and clean oil product solution. The present invention creates a density gradient that enables over 95% recovery of clean oil and over 99% reduction of contaminants such as asphaltenes and particulate matter depending on the properties of the contaminated organic material.

First claim

The invention claimed is:

1 . A process for separating contaminants from a contaminated feedstock comprised of:
combining a contaminated feedstock and supercritical water to form a supercritical water and feedstock solution in a hydrothermal separation vessel, said hydrothermal separation vessel including an upper separation zone and a bottom concentration zone; maintaining a temperature and pressure within the hydrothermal separation vessel to achieve a vertical density gradient therein such that the separation zone of the hydrothermal separation vessel exhibits a lower density than the concentration zone of the hydrothermal separation vessel, to cause the contaminants to separate from the solution in the separation zone and to form a product stream; removing the product stream from the separation zone of the hydrothermal separation vessel; and removing the contaminants from the concentration zone of the hydrothermal separation vessel.

2 . The process of claim 1 , wherein the separation zone is maintained at a pressure greater than 22.1 MPa and a temperature greater than 374° C.

3 . The process of claim 1 , wherein the hydrothermal separation vessel includes a mid-level, mixing zone located between the separation zone and the concentration zone, wherein the contaminated feedstock and the water are each separately fed into the mixing zone, and wherein sufficient shear and mixing is provided in the mixing zone to cause dissolution of any soluble components of the feedstock into the supercritical water and separation of the contaminants as insoluble components.

4 . The process of claim 1 , wherein the contaminated feedstock and supercritical water are mixed together prior to delivery to the hydrothermal separation vessel.

5 . The process of claim 1 , wherein the contaminated feedstock is preheated indirectly prior to mixing with the supercritical water or is heated directly by mixing with the supercritical water.

6 . The process of claim 1 , wherein the separation zone of the hydrothermal separation vessel is configured to achieve up-flow of the supercritical water and any dissolved portions of the feedstock.

7 . The process of claim 1 , wherein dimensions of the hydrothermal separation vessel and feed rates of the supercritical water and contaminated feedstock are controlled to result in a vertical velocity that is less than a gravity settling rate of the contaminants.

8 . The process of claim 7 , wherein the vertical velocity in the hydrothermal separation vessel is between 0.1 and 10 feet per minute.

9 . The process of claim 1 , wherein the density gradient in the hydrothermal separation vessel results in plug flow in the vessel.

10 . The process of claim 1 , wherein a temperature in the separation zone of the hydrothermal separation vessel is between 380° C. and 450° C., or up to the highest temperature that can be achieved without causing thermal cracking, coking, or reaction of the feedstock.

11 . The process of claim 10 , wherein the temperature in the separation zone of the hydrothermal separation vessel is maintained directly by introduction of supercritical water to the hydrothermal separation vessel or indirectly by internal or external heat exchangers or heaters applied to the hydrothermal separation vessel.

12 . The process of claim 1 , wherein a temperature in the concentration zone is maintained below a reaction temperature of the contaminants and above a pour point temperature of the contaminants.

13 . The process of claim 1 , wherein the product stream is continually removed from the hydrothermal separation vessel and the contaminants are continually removed from the concentration zone of the hydrothermal separation vessel.

14 . The process of claim 1 , wherein a ratio of supercritical water-to-feedstock is between 1:10 to 3:1.

15 . The process of claim 1 , wherein the contaminated feedstock comprises petroleum crude oils, bitumen, petroleum refinery streams, waste or reclaimed oils and/or crude oil storage tank residue; renewable oils; soaps, algae and/or algal oil, and pyrolysis oil; and the contaminants comprise coke or mineral particulates, asphaltenes, catalyst fines, resins, salts, metals, and/or minerals.

16 . The process of claim 1 , wherein the temperature in the hydrothermal separation vessel is controlled by supplying split streams of supercritical water and/or split streams of heated contaminated feedstock at differing locations along a vertical height of the hydrothermal separation vessel between the separation zone and the concentration zone.

17 . The process of claim 1 , including the addition of separation aids to selectively enhance the separation and recovery of high molecular weight, non-paraffinic hydrocarbons or to selectively enhance the separation and removal of polar contaminants.

18 . A system for separating contaminants from a contaminated feedstock comprised of:
a hydrothermal separation vessel including at least one inlet for receiving a feedstock and a supercritical water, said hydrothermal separation vessel including an upper separation zone, a bottom concentration zone, and a mid-level mixing zone located between the separation zone and the concentration zone; a mixing device for combining the contaminated feedstock and the supercritical water to form a solution, wherein said mixing device is positioned inline prior to the at least one inlet of the hydrothermal separation vessel or positioned within the hydrothermal separation vessel, wherein said hydrothermal separation vessel, feedstock, and supercritical water cooperate together to achieve a vertical density gradient within the hydrothermal separation vessel, wherein the separation zone of the hydrothermal separation vessel exhibits lower density than the concentration zone of the hydrothermal separation vessel to cause the contaminants to separate from the solution in the separation zone and to form a product stream; at least one outlet for removing the product stream from the separation zone of the hydrothermal separation vessel; and at least one outlet for removing the contaminants from the concentration zone of the hydrothermal separation vessel.

19 . The system of claim 18 including multiple inlets within the hydrothermal separation vessel for receiving split streams of supercritical water and/or split streams of heated contaminated feedstock therein, wherein the multiple inlets are located at varying vertical heights between the separation zone and the concentration zone of the hydrothermal reactor to control the temperature of the hydrothermal separation vessel.

20 . The system of claim 18 , wherein the temperature in the separation zone of the hydrothermal separation vessel is between 380° C. and 450° C., or up to the highest temperature that can be achieved without causing thermal cracking, coking, or reaction of the feedstock, and the temperature in the concentration zone is maintained below a reaction temperature of the contaminants and above a pour point temperature of the contaminants.

Assignees

• Applied Res Associates Inc

Inventors

• Coppola Edward N
• Red Jr Charles
• Nana Sanjay
• Pelt Kenneth D
• Wahlgren Jocelyn Marie

Classifications

• B01D11/0488

  Flow sheets · CPC title

• B01D11/0446

  Juxtaposition of mixers-settlers · CPC title

• C10G31/08

  by treating with water · CPC title

• B01D11/0403

  with a supercritical fluid · CPC title

• C10G55/04 Primary

  including at least one thermal cracking step · CPC title