Thermal apparatus and process for removing contaminants from oil

• US 20020029996A1
• Filed: 05/22/2001
• Published: 03/14/2002
• Est. Priority Date: 09/27/1996
• Status: Active Grant

• Current Assignee: UMATAC Industrial Processes Inc. a Company of ThyssenKrupp
• Original Assignee: Alberta Oil Sands Tech and Research Authority
• Inventors: Odut, Steve, Taciuk, Gordon, Taciuk, William, Wheeler, Charlie
• Granted Patent: US 6,589,417 B2
• Time in Patent Office: Days
• US Class Current: 208/126
• CPC Class Codes: B01J 19/28 Moving reactors, e.g. rotary drums B01J19/08 takes precedence
• CPC Class Codes: B01J 2208/00212 Plates; Jackets; Cylinders
• CPC Class Codes: B01J 2208/00247 Reflux columns
• CPC Class Codes: B01J 2208/00504 by means of a burner
• CPC Class Codes: B01J 2208/00513 using inert heat absorbing solids in the bed
• CPC Class Codes: B01J 2208/0053 Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 6/008 Pyrolysis reactions of hydrocarbons C10G9/00
• CPC Class Codes: C10B 1/10 Rotary retorts
• CPC Class Codes: C10B 47/30 in rotary ovens or retorts
• CPC Class Codes: C10B 55/02 with solid materials
• CPC Class Codes: C10G 9/28 with preheated moving solid material
• CPC Class Codes: C10M 175/0025 by thermal processes

Abstract

Used oil is treated in a reactor to remove contaminants. The reactor comprises a rotating vessel housed within a heating chamber. The inside of the vessel is indirectly heated by conduction through the vessel walls. The vessel contains a permanently resident charge of non-ablating, coarse granular solids. Within the vessel, the oil is vaporized and pyrolysed, producing a hydrocarbon vapor. Coke is formed as a byproduct. Contaminants, such as metals and halides become associated with the coke. The coarse granular solids scour and comminute the coke to form fine solids. The fine solids are separated from the coarse solids and are removed from the vessel. The hydrocarbon vapors are separated from any fine solids and are routed to a vapor condensation system for producing a substantially contaminant-free product oil. The contaminant-rich solids are collected for disposal.

Claims

1. A thermal process for removing contaminants from oil comprising:

providing a rotating vessel having a circumferential wall and end walls forming an internal reaction zone;

providing a charge of non-ablating coarse granular solids which form a bed within the reaction zone;

heating the outside of the vessel so as to indirectly heat the reaction zone and the bed of coarse granular solids by conduction through the vessel'"'"'s walls;

feeding contaminated oil through the one of the vessel'"'"'s end walls so that it discharges into the reaction zone;

vaporizing and pyrolyzing the oil within the hot reaction zone to produce hydrocarbon vapours and deposit coke, whereby substantially all of the contaminants become associated with the coke;

scouring the vessel walls with the bed of coarse granular solids to remove coke deposits and comminute the coke into fine solids;

separating the fine solids from the bed of coarse solids;

removing the hydrocarbon vapours and fine solids from the reaction zone;

recovering the fine solids and vapours separately; and

condensing the vapours to recover substantially contaminant-free product oil

2. The thermal process as recited in claim 1 wherein some of the fine solids are removed from the reaction zone by elutriation with the hydrocarbon vapours.

3. The thermal process as recited in claim 1 wherein the fine solids are removed from the reaction zone by a combination of:

elutriation of fine solids with the hydrocarbon vapour; and

mechanically separating fine solids from the bed of coarse solids and conveying the fine solids out of the reaction zone.

4. The thermal process as recited in claim 3 wherein the feed oil is discharged so as to contact the circumferential vessel wall.

5. The thermal process as recited in claim 3 wherein the feed oil is discharged so as to contact the bed of coarse solids.

6. The thermal process as recited in claim 3 wherein the feed oil is preheated, to a temperature sufficient to vaporize water, prior to discharge into the reaction zone.

7. The thermal process as recited in claim 4, 5, or 6 wherein the coarse solids are a plurality of steel chips.

8. The thermal process as recited in claim 1 wherein the contaminants comprise metals and fine solids.

9. The thermal process as recited in claim 6 wherein the contaminants include water.

10. Apparatus for removing contaminants from oil comprising:

a rotating vessel having a circumferential wall and end walls forming an internal reaction zone;

a charge of non-ablating coarse solids which form a bed within the reaction zone;

means for heating the outside of the vessel so as to indirectly heat the reaction zone and the bed of coarse granular solids by conduction through the vessel'"'"'s walls;

means for feeding contaminated oil into the reaction zone so that the oil vaporizes and pyrolyses, forming hydrocarbon vapours and depositing coke, whereby substantially all of the contaminants become associated with the coke, the bed of coarse granular solids acting to scour the coke deposits and comminute the coke and form fine solids;

means for removing the hydrocarbon vapours from the reaction zone; and

means for separating the fine solids from the bed of coarse solids and removing the fine solids from the reaction zone separately from the hydrocarbon vapours to produce a contaminant-rich solids product; and

condensation means for condensing the hydrocarbon vapours and producing a substantially contaminant-free product oil.

11. The apparatus as recited in claim 10 wherein the means for indirectly heating the reaction zone comprises:

a housing forming a heating chamber surrounding the vessel and forming an annular space therebetween;

burner means for circulating combustion gases in the annular space for transferring heat to the vessel; and

an exhaust stack for conducting combustion gases from the heating chamber.

12. The apparatus as recited in claim 11 wherein

the means for feeding contaminated oil into the reaction zone comprises a conduit extending through one end wall of the vessel and having means for distributing the oil within the zone, and

the means for removing the hydrocarbon vapours from the reaction zone comprises a vapour pipe which extends along the axis of the vessel and projects through one end wall of the vessel.

13. The apparatus as recited in claim 12 further comprising a cyclone positioned in-line with the vapour pipe for separating fine solids which accompany the hydrocarbon vapours.

14. The apparatus as recited in claim 10 wherein the means for separating the fine solids from the coarse granular solids and removing them from the reaction zone comprise:

a conduit having a solids entrance adjacent the periphery of the vessel wall, a solids exit adjacent the vessel'"'"'s axis and at least two solids conveyance portions extending therebetween,

the first conveyance portion of the conduit having first and second ends, both ends lying adjacent the vessel'"'"'s circumference, wherein the inner radius of the conduit is screened for excluding coarse granular solids and admitting only fine solids into the conduit,

the second conveyance portion of the conduit having first and second ends, the first end being connected to the second end of the first conveyance portion, the second conveyance portion spiralling radially inwardly to discharge at its second end into the vapour pipe; and

means associated with the vapour pipe for transport of the fine solids out of the reaction zone.

15. The apparatus as recited in claim 14 wherein the means associated with the vapour pipe for transporting fine solids out or the reaction zone comprise a screw conveyor extending along the bottom of the vapour pipe and a discharge hopper located external to the heating chamber.

16. The apparatus as recited in claim 10 wherein the bed of coarse granular solids comprise a plurality of steel chips.