Oil Recovery from Hydrocarbonaceous Solids
A thermal method and apparatus are provided for recovering hydrocarbons from hydrocarbon-containing solids such as oil shale, tar sands and other hydrocarbonaceous solids. The method includes combusting a pre-determined fraction of the hydrocarbon bearing aggregate solid in a closed reactor, thereby providing exothermic heat and gaseous combustion products which raise the temperature and pressure of the aggregate in the reactor causing the remaining solid hydrocarbon to undergo pyrolysis, phase changes and composition changes simultaneously upgrading the hydrocarbon product. The products of the operation are then produced and condensed.
This application claims priority from disclosure document applications numbers 589080, 589081, 589082, 589083, filed Nov. 2, 2005 and 589594 filed Nov. 9, 2005 and provisional patent 60/781,283 by Dr. Henry Crichlow.
BACKGROUND OF THE INVENTION Field of the InventionThis invention relates to the recovery of oil from hydrocarbonaceous solids. More particularly, the invention relates to a method and apparatus whereby hydrocarbons are extracted from tar sands, oil shales and similar materials by using a thermal process which simultaneously combines combustion and pyrolysis of the hydrocarbonaceous material.
SUMMARY OF THE INVENTIONThe method of the present invention relates to a new and improved method and apparatus for the thermal extraction of oil other valuable hydrocarbons from crushed hydrocarbonaceous solids, such as tar sands and oil shale. The terms tar sands and oil sands have the same meaning in this application and can be interchanged.
Specifically, the present invention provides for extracting oils and other hydrocarbons from crushed hydrocarbonaceous solids which comprises crushing the solids to provide a substantially uniform feed composition. The crushed solid aggregates are then thermally treated in a generally vertical closed reactor in an exothermic combustion process in which a fraction of the hydrocarbon is combusted to generate heat in-situ, this heat energy produces an elevated temperature and pressure environment inside the reactor in which the solid hydrocarbons subsequently undergo phase changes and pyrolysis and also are chemically upgraded to provide a higher quality hydrocarbon product.
Specifically, the present invention provides a method and apparatus for the thermal extraction of hydrocarbons from solid hydrocarbon-bearing aggregates using a substantially vertical pressurized reactor. The method provides for a thermal modification of the solid or semi-solid hydrocarbon by providing a high temperature and high pressure environment resulting from the exothermic combusting of a pre-determined fraction of the native hydrocarbon with an oxidizer in a closed reactor apparatus.
The primary features of the apparatus include a reactor and an associated system which provides an oxidizer source, an aggregate feed system, a production system for the hydrocarbon products and a heat exchanger for utilizing residual heat in the spent solids. This reactor is designed to operate under elevated temperatures and pressures which are developed during the thermal processing of the hydrocarbon feed. In addition to the reactor components, several accessory and peripheral elements are required to separate the solid, liquid and vapor products of the invention. The feed system provides for inputting the crushed aggregate into the reactor. The oxidizer system provides a source of oxygen which is needed and which is introduced into the reactor to maintain combustion of only a fractional part of the hydrocarbon in the aggregate.
In a more detailed feature of the present invention, the hot gases produced under pressure in the thermal process permeate the solid material, simultaneously raising the temperature thereby lowering the viscosity of the hydrocarbon, in addition, also pyrolyzing part of the hydrocarbon and vaporizing part of the hydrocarbon material.
In yet a more detailed aspect of the invention the exothermic combustion process oxidizes only a predetermined fraction of the in-place hydrocarbon, a fraction sufficient to raise the temperature of the remaining material to a level needed to complete the thermal processes. The quantity of oxidizer is pre-calculated stoichiometrically and since only a fraction of hydrocarbon is oxidized, the remaining hydrocarbon can be thermally modified and produced in this new invention.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.
An objective of this invention is to thermally extract hydrocarbons from solid hydrocarbonaceous materials like oil sands, oil shales and other bitumen bearing material using a closed pressurized reactor.
A specific objective of this invention is to implement a controlled combustion of a fraction of the native hydrocarbon in the reactor to raise the temperature and pressure of the remaining aggregate material in the reactor.
A further objective is to pyrolize a part of the remaining bitumen or hydrocarbon in the aggregate material.
Another specific objective is to lower the viscosity of the remaining hydrocarbon in place in the aggregate by virtue of the elevated temperatures and pressures developed in the reactor during the combustion reaction.
Another specific objective is to vaporize part of the remaining unburnt hydrocarbon in place in the aggregate by virtue of the elevated temperatures and pressures developed in the reactor.
Another specific objective is to physically displace and produce significant amounts of the remaining lowered viscosity hydrocarbon in place in the aggregate by circulating a gas through the reactor system
A further objective is to utilize a plurality of catalysts to accelerate the thermal reactions taking place in the reactor.
A further objective is to utilize hydrogen to modify the thermal reactions taking place in the reactor.
A further objective is to produce the modified hydrocarbons and vapors from the reactor.
A further objective is to scavenge and recuperate the heat remaining in the spent aggregate and transfer this heat to the incoming aggregate to the reactor.
PRIOR ARTMost of the prior work in this technological area falls into three basic categories. The first is a fluidized bed, the second is a rotary kiln system and the last is a solvent type extraction process.
Patent 20050173305 teaches a basic thermal rotary kiln method for treating crushed hydrocarbonaceous solids in a horizontal rotary kiln with a hot gas and injected hydrocarbon. The in situ hydrocarbon is vaporized and the crushed solids are left behind.
Patent 20050252833 describes a typical fluidized bed process that includes treating the oil sand (tar sand) or shale to produce a fluidizable feed, feeding the fluidizable feed to a fluidized bed reactor, which is then treated with hydrogen.
Patent 5320747 illustrates a combined aqueous solvent process and a pyrolysis process in which the tar sand is first washed with aqueous solvents and then treated in pyrolysis process to extract the hydrocarbon.
Patent 4054492 teaches a dry distillation process in which the ground-up tar sand material is treated by mixing in a distillation zone with a heat carrier comprising fine-grained dry distillation residue which is heated by hot combustion gases for several minutes at temperatures of 750 deg. to 850 deg. C.
Patent 4160720 describes an apparatus for tar sand processing that is essentially a vertical sequence of two fluidized beds in which the tar sand is sequentially pyrolized first between 350 deg. C. to 500 deg. C. and then combusted between 500 deg. C. and 700 deg. C. In this apparatus there is a thermal connection between the two fluidized beds using a set of pipes in which a hot liquid like molten sodium, potassium or cesium is used as the working fluid to transfer heat energy from the combustion zone to the pyrolysis zone.
Patent 4486294 describes a flotation system for recovering bitumen, patent 4470899 uses a digester with kerosene, while patent 4120776 uses caustic solvent digestion while patent 4298457 upgrades liquid bitumen products with hydrogen at high temperatures and pressures.
Patent 5681452 teaches a high temperature, high-pressure reactor which uses a stream of heated hydrogen gas at 910 deg. F. to calcine and process oil shale and tar sands by hydrogenation and hydrocracking in a closed 12 ft diameter by 100 ft high system.
Patent 4585543 utilizes extremely finely divided shale or tar sands particles in the range of 0.5 to 500 microns which are flashed at 1400 deg. F. in a reactor in less than two seconds. The solid fines and gaseous products are separated. The remaining hydrocarbon in the solids is burnt outside of the reactor to preheat the finely divided feed.
Chemical solvent and other combined solvent technologies for treating carbonaceous materials are taught in patents, 5320746, 5017281, 4804459, 4752358, 4596651, 4399314, 4161442, 4067796, 4027731, 2825677, 3041267, 3475318, 3459653, 2965557, 3117922, 3553099, 3392105 and 3948754. Retorting, calcining and related technologies for treating carbonaceous materials are discussed in patents, 5902554, 4707248, 4519894, 4415432, 4409090, 4337143, 4197183, 4133739, 4017379 and 3972690.
The University of Utah in Ref. 4 provides a very comprehensive discussion of tar sand recovery based on several laboratory studies involving fluidized beds.
Pressurized fluidized bed reactors shown in Refs. 5 and Ref. 6 have been proposed and utilized to gasify coal and potentially to process carbonaceous material. These devices partially gasify coal and produce a syn-gas. They operate at high temperatures, about 1800 deg. F. and with steam pressures approaching 6,000 psi.
References 6, and 7 provide detailed analyses of the recovery and upgrading of hydrocarbons from tar sands and oil shales. Reference 8 describes the Lurgi_Ruhrgas process which uses dry distillation techniques to recover up to 70% of the hydrocarbon by breaking down the mined material into liquids, vapor and entrained solids at high retort temperatures.
In addition to the above methods, a number of oil recovery methods related to oil shale and tar sands have been tested in the laboratory or in many operations in the field. These processes involve various techniques such as hot water processes, cold water processes, solvent processes, thermal processes and the like, all possess certain limitations which make them difficult to implement economically or mechanically in the field. Further, in many of these processes a high percentage as much as 20% of the original hydrocarbon remains in the spent residual solid product. This residual material is a significant loss of hydrocarbon revenue which is left behind in the spent material. The technology described here is a means to recover a relatively high percentage of the in-situ hydrocarbon and the residual material is limited only by the level of combustion that the operator is willing to tolerate in the combustion phase of this method. A method which would be effective in these oil shales and tar sands while leaving a small residue of hydrocarbons would be a significant advance in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention described herein is method and apparatus which is used to rapidly extract hydrocarbon from tar sands, oil shales and other hydrocarbon containing solids. The process uses a thermal device called a pressure vessel as an extraction unit or reactor, which utilizes the exothermic heat generated by combusting a predetermined fraction of the hydrocarbon in place, in contact with a pre-determined amount of oxidizer, in a closed pressure vessel under elevated temperatures and pressures to raise the temperature of the native materials and thus initiate a change of phase and pyrolysis of the solid hydrocarbon converting the solid hydrocarbons to hydrocarbon liquids and gases. Pyrolysis is defined in this application as the decomposition or transformation of a compound caused by heat.
As combustion takes place, the pressure and temperature inside of the closed vessel increase very rapidly. The hot combustion gases penetrate the bigger aggregates of rock and heat the hydrocarbons in them in a chain reaction which in turn produces a thermal disintegration and pyrolysis of the aggregates, decreasing their particle size leaving them hot, dry and clean with a significant fraction of the hydrocarbons in a hot gaseous form and permeating the pore spaces of the aggregate matrix. The hydrocarbon burning is controlled by providing only sufficient oxidizer material to burn a calculated amount of hydrocarbon. After the oxidizer is consumed, no further burning occurs and the remaining native hydrocarbon remains in the pore spaces. The resulting increase in pressure is used to help drive the gases out of the vessel. This hydrocarbon product, which has gone through a change of state and pyrolysis, is then condensed and collected. The process can handle large amounts of material with relatively small extraction units.
Table 1 shows a list of the elements of the method. Referring to
Referring to
By using a standard system energy balance well known in the industry, the quantity of oxidizer 12a that is needed to fully combust a pre-determined fraction of the hydrocarbon 27 and, to simultaneously raise the temperature of the aggregate material 1 to the required temperature for phase conversion, is computed stoichiometrically. A typical computation of an energy balance is shown in Table 2. In this table, the estimated quantity of bitumen to be fully combusted to raise the temperature of the remaining combined material is calculated. In practice, there are several process variables which influence the energy balance and those practiced in the field can easily modify the computations to achieve desired results. In one embodiment, the oxidizer 12a can be atmospheric oxygen, on another embodiment, it can be pure oxygen or an enriched air-oxygen mixture or still another embodiment the oxidizer can be any other chemicals capable of producing oxygen in suitable concentrations and quantities. In another embodiment, additional highly volatile fuel like a light hydrocarbon can be used in small amounts to aid in the initiation of combustion of the hydrocarbon. This fuel 12d is injected into the aggregate pack 1 either before or after the oxidizer 12a. In field operations, this energy balance is computed and the injected oxidizer quantity is controlled in real time by a control system which analyzes the input quality and quantity of the aggregate material and rates of feed to the reactor.
Referring to
As an example, the heat released by the combustion of bitumen 27 is approximately 18,500 BTU/lb while the products of combustion are principally carbon dioxide and water.
Referring to
A further embodiment of the method provides for the inclusion of a chemical catalyst with the aggregate material 1 to reduce the effects of impurities like sulfur in the feed stream. A plurality of different catalysts for example, compounds of calcium or magnesium, which are well known in the industry are optionally used to remove the impurities and their products from the final products of the thermal process.
After a predetermined time, which can be as short as two minutes or as long as 60 minutes, the fluid in the reactor 2 is vented to allow the vaporized products to be produced. The residence time in the pressure vessel 2 depends on the size of the vessel and the intrinsic properties of the hydrocarbonaceous solid material. The vaporized products 43 contain principally a higher grade hydrocarbon, combustion products and solids. A higher grade hydrocarbon is one of higher API gravity.
In another embodiment of the invention, referring to
A further embodiment to the invention is shown in
In one embodiment, the invention provides a method in which hydrogen can be optionally injected into the reactor to provide a reactant for hydrocracking and hydrogenation of the hydrocarbon products. Referring to
Another embodiment of the invention is shown in
Another embodiment of the invention is shown in
In one embodiment of the invention, the heat energy stored in the hot spent aggregate at the output feed system 3 shown in
It is an object of the invention, therefore, to provide a new and efficient method for the extraction of hydrocarbons from solids containing such material and particularly from tar sands, oil shales and other heavy oil deposits. Another object of the present invention is to provide the rapid and economical production of various products from the hydrocarbonaceous solids.
REFERENCES
- 1. SPE 1813, “Equilibrium Revaporization of Retrograde Condensate by Dry Gas Injection”, Society of Petroleum Engineers, Dallas Tex., SPE Journal, March 1968, p 87-94. www.spe.org
- 2 Solid Rocket Booster Engines Design, http://en.wikipedia.org/wiki/Solid-rocket.
- 3. SPE 35392, “Combustion/Oxidation Behavior of Athabasca Oil Sands Bitumen”, Society of Petroleum Engineers, Dallas Tex. www.spe.org
- 4. Annual Review of Energy, November 1987, Vol. 12. pages 283-356. “Tar Sand Research and Development at the University of Utah”. http://arjournals.annualreviews.org/doi/pdf/10.1146/annurev.eq.12.110187.001435
- 5. “Pressurised Fluidised Reactor”, www.energy.kth.se/proj/projects/SUSPOWER/Downloads/Pressurized%20fluidized%20bed%20reactor.pdf
- 6. “Development of Foster Wheeler's Vision 21 Partial Gasification Module”, A. Robertson, Foster Wheeler Development Corp., Vision 21 Review Program, Livingston N.J. Nov. 6, 2001.
- 7. “Oil sand and Oil Shale Chemistry”, Otto P. Strausz and Elizabeth M Lown., Verlag Chemie, NY. Weinhem 1978. ISBN 0-89573-102-9
- 8. “Heavy Oil and Tar Sands Recovery and Upgrading”, M. M Schumacher, Editor, Noyes data Corporation, Park Ridge, N.J. USA. 1982. ISBN-0-8155-0893-X.
9. “Oil Sands Fuel of the Future”, L. V. Hills, Editor, McAra printing, Calgary, Canada. 1974.
Claims
1. A thermal method for treating hydrocarbonaceous solids to extract hydrocarbons therefrom; the method comprising the steps of:
- (a) crushing the hydrocarbonaceous solids to form an aggregate;
- (b) loading the crushed aggregate into a closed reactor vessel;
- (c) treating the aggregate material in a reactor to obtain a mixture comprising vaporized hydrocarbon products, enriched gas, and spent solids by: (i) injection of an oxidizer into the reactor, (ii) providing an ignition source, (iii) combustion of a fraction of the solid hydrocarbon in the aggregate to provide heat energy inside the reactor, (iv) allowing the combustion heat to raise the temperature and pressure inside the reactor, (v) pyrolyzing the remainder of the solid hydrocarbon in the reactor vessel, (vi) controlling the temperature within the reactor vessel, (vii) controlling the pressure within the reactor vessel, and (viii) allowing the contents of the reactor to equilibrate for a given residence time to allow the vaporization of the products of combustion and pyrolysis;
- (d) removing the produced mixture from the said reactor.
2. The method of claim 1, wherein the temperature within the reactor ranges between 500 deg. F. and 1500 deg. F.
3. The method of claim 1, wherein the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure and the pressure ranges from 15 psi to 5,000 psi.
4. The method of claim 1, wherein the step of providing heat from the combustion reaction to the aggregate hydrocarbon material comprises the sub-step of:
- burning a selected quantity (Q) of the hydrocarbon material, such that the heat of combustion per unit mass of the hydrocarbon material is (Hc), and the heat energy produced causes a phase change in at least some hydrocarbons within the reactor; and
- wherein heat energy provided to the reactor is equal to or less than Q*Hc and the said heat is available to heat the remaining material and to raise the temperature of the contents of the reactor wherein an average composite heat capacity of the material is Cm, and wherein the resultant temperature rise is less than Q*Hc/(M*Cm), where M is the total mass of material in the reactor.
5. The method of claim 1, wherein combustion of the crushed hydrocarbonaceous solids occurs at a temperature between 900.deg. F. and 1300.deg. F.
6. The method of claim 1, wherein the aggregate solids have a residence time ranging between 1 minute and 60 minutes in the reactor.
7. The method of claim 1, wherein the treated hydrocarbon solid is tar sand hydrocarbon material.
8. The method of claim 1, wherein the treated hydrocarbon solid is oil shale hydrocarbon material.
9. The method of claim 1, wherein the produced mixture comprises condensable hydrocarbons having an API gravity of at least 15° API.
10. The method of claim 1, wherein the produced mixture comprises non-condensable hydrocarbons and the total molar fraction of C1 to C4 non-condensable hydrocarbon components is greater than 0.001.
11. The method of claim 1, wherein the step of treating the aggregate material further comprises the sub-steps of:
- providing a specified quantity of hydrogen gas to the combustion process to hydrogenate hydrocarbons within the aggregate mixture, and
- heating a part of the aggregate by the heat of hydrogenation reaction.
12. The method of claim 1, wherein the step of treating the aggregate material further comprises the sub-step of:
- providing a catalyst which is added to the aggregate to control the sulfur reactions in the combustion and pyrolysis process within the aggregate mixture.
13. The method of claim 12, wherein the catalyst is a plurality of chemical compounds comprising a mixture of calcium and magnesium compounds.
14. The method of claim 1, wherein the step of treating the aggregate material further comprises the sub-step of:
- providing a gas re-circulating system operatively associated with the reactor to circulate a gas through the combusted aggregate material within the reactor.
15. The method of claim 14, wherein the circulated gas is a hydrocarbon gas.
16. The method of claim 14, wherein the circulated gas is an inert gas.
17. The method of claim 14, wherein the circulated gas is flue gas.
18. The method of claim 14, wherein the circulated gas is air.
19. The method of claim 14, wherein the circulated gas is a combination of a plurality of gases comprising hydrocarbon gases and non-hydrocarbon gases.
20. The method of claim 14, wherein the circulated gas scavenges, entrains, accumulates and transports the hydrocarbon products present in the aggregate pore spaces.
21. The method of claim 14, wherein the gas is circulated for a finite time equal to or greater than the time required to circulate at least 5 pore volumes of the reactor volume.
22. The method of claim 1, wherein the oxidizer comprises a combination of gases containing oxygen in the range of 1 mol % oxygen to 100 mol % oxygen.
23. The method of claim 1, wherein the oxidizer comprises a combination of chemicals capable of producing a gas containing oxygen in the range of 1 mol % oxygen to 100 mol % oxygen.
24. An apparatus for carrying out a thermal method for treating hydrocarbonaceous solids to extract hydrocarbons therefrom; the said apparatus comprising:
- (a) a pressurized reactor having a materials handling system for feeding the aggregate into the reactor and removing the spent material from the reactor;
- (b) means for supplying oxidizer material for the reactor operatively connected to the reactor and containing oxidizer material;
- (c) means for igniting the combustion process in the reactor;
- (d) means for enhancing the initiation of the combustion process by using a fuel pack containing highly combustible material;
- (e) means for disposing a vertical combustion tunnel axially and operatively in the center of the aggregate column;
- (f) means operatively connected to the reactor for circulation of a gas through the reactor contents, so that the hydrocarbons products produced in the combustion process can be entrained in the circulating gas stream;
- (g) means for storing a hydrogen gas supply which is available for injection into the reactor;
- (h) means operatively connected to the reactor for injecting hydrogen gas into the reactor;
- (i) a coolant system;
- (j) a heat recovery and pre-heat system;
- (k) means operatively connected to the reactor for injecting low molecular weight hydrocarbon material into the reactor;
- (l) means for condensation and separation of products of the combustion process; and
- (m) means for rapidly releasing the ends or caps of the reactor vessel so that the reactor can be either filled with aggregate feed or emptied of spent material in less than 15 minutes.
25. The apparatus of claim 24, wherein the ignition means is implemented by a plurality of separate devices disposed at intervals throughout the reactor device.
26. The apparatus of claim 24, wherein the combustion tunnel is implemented with a variety of regular or irregular cross-sections so that greater combustion efficiency of the aggregate material occurs.
27. The apparatus of claim 24, wherein a plurality of combustion tunnels are implemented so that combustion efficiency can be maximized.
28. The apparatus of claim 24, wherein the condensation means allow the produced fluids to be condensed to a liquid state.
29. The apparatus of claim 24, wherein the separation means allow the solids in the produced fluids to be separated from the liquids in the produced fluids.
30. The apparatus of claim 24, further comprising a heat recovery unit operatively associated with the reactor for recovery of heat from spent solids to preheat incoming feed material.
31. The apparatus of claim 24, wherein the fuel pack extends substantially throughout the length of the combustion tunnel.
32. The apparatus of claim 24, wherein the fuel pack fuel comprises a highly combustible material.
33. The apparatus of claim 24, wherein the fuel pack comprises a solid material.
34. The apparatus of claim 24, wherein the fuel pack comprises a gel material.
35. The apparatus of claim 24, wherein the fuel pack comprises an encapsulated liquid material.
36. The apparatus of claim 24, wherein the fuel pack comprises a combination of solid, liquid and gel materials.
37. The apparatus of claim 24, wherein the reactor vessel is substantially spherical in shape.
38. The apparatus of claim 24, wherein the reactor vessel is cooled by a circulating fluid.
39. The apparatus of claim 24, wherein the reactor vessel is wrapped by a reinforced cement sheath.
40. The apparatus of claim 24, wherein the reactor vessel is wrapped by a reinforced fiber sheath.
41. The apparatus of claim 24, wherein the reactor vessel is substantially vertical in shape.
42. The method of claim 1, wherein the reactor vessel is substantially vertical in shape.
43. The method of claim 1, wherein the reactor vessel is substantially spherical in shape.
Type: Application
Filed: Apr 10, 2006
Publication Date: Sep 13, 2007
Inventor: Henry Crichlow (Norman, OK)
Application Number: 11/279,128
International Classification: C10G 1/08 (20060101); C10G 1/06 (20060101);