U.S. patent application number 11/279128 was filed with the patent office on 2007-09-13 for oil recovery from hydrocarbonaceous solids.
Invention is credited to Henry B. Crichlow.
Application Number | 20070209972 11/279128 |
Document ID | / |
Family ID | 38477843 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070209972 |
Kind Code |
A1 |
Crichlow; Henry B. |
September 13, 2007 |
Oil Recovery from Hydrocarbonaceous Solids
Abstract
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.
Inventors: |
Crichlow; Henry B.; (Norman,
OK) |
Correspondence
Address: |
HENRY CRICHLOW
330 W. GRAY ST.
SUITE 504
NORMAN
OK
73069
US
|
Family ID: |
38477843 |
Appl. No.: |
11/279128 |
Filed: |
April 10, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60781283 |
Mar 13, 2006 |
|
|
|
Current U.S.
Class: |
208/408 ;
208/407; 208/419; 208/427 |
Current CPC
Class: |
C10G 1/06 20130101; C10G
1/02 20130101; C10G 1/08 20130101 |
Class at
Publication: |
208/408 ;
208/427; 208/419; 208/407 |
International
Class: |
C10G 1/08 20060101
C10G001/08; C10G 1/06 20060101 C10G001/06 |
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 (H.sub.c), 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*H.sub.c 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 C.sub.m, and wherein the resultant temperature
rise is less than Q*H.sub.c/(M*C.sub.m), 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.degree. API.
10. The method of claim 1, wherein the produced mixture comprises
non-condensable hydrocarbons and the total molar fraction of
C.sub.1 to C.sub.4 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.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] 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 Invention
[0002] This 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 INVENTION
[0003] The 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] A further objective is to pyrolize a part of the remaining
bitumen or hydrocarbon in the aggregate material.
[0013] 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.
[0014] 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.
[0015] 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
[0016] A further objective is to utilize a plurality of catalysts
to accelerate the thermal reactions taking place in the
reactor.
[0017] A further objective is to utilize hydrogen to modify the
thermal reactions taking place in the reactor.
[0018] A further objective is to produce the modified hydrocarbons
and vapors from the reactor.
[0019] 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 ART
[0020] Most 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] The University of Utah in Ref. 4 provides a very
comprehensive discussion of tar sand recovery based on several
laboratory studies involving fluidized beds.
[0031] 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.
[0032] 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.
[0033] 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
[0034] FIG. 1 shows a schematic of the generalized layout of the
reactor cell and the accessory equipment used in the recovery of
hydrocarbons.
[0035] FIG. 2 shows a generalized schematic of the pressure vessel
reactor and the associated gas circulating system implemented.
[0036] FIG. 3 shows an idealized microscopic view of the tar sand
material with sand grains surrounded by a connate water film and
the bitumen layer.
[0037] FIG. 4 shows schematically shows the directional movement of
hot gases successively into the matrix of a tar sand aggregate
during the thermal process.
[0038] FIG. 5 shows a top cross-section view of a "star" shaped
combustion tunnel in the center of the pressure vessel.
[0039] FIG. 6 shows a side view cross-section of the pressure
vessel with contained aggregate and the vertically disposed
combustion tunnel.
[0040] FIG. 7 shows a top cross-section view with a circular shaped
combustion tunnel.
[0041] FIG. 8 shows an implementation of a fuel pack in the
combustion tunnel.
[0042] FIG. 9 shows a cross-sectional view of the movement of the
burn sequence as the combustion front moves radially through the
hydrocarbonaceous aggregate from the center combustion tunnel
outwards to the periphery of the reactor.
[0043] FIG. 10 shows an implementation of a fiber wrapped
reactor.
[0044] FIG. 11 shows an implementation of a cement wrapped
reactor.
[0045] FIG. 12 shows an implementation of a plurality of reactors
which are cooled to lower the temperature of the reactor shell.
DESCRIPTION OF THE INVENTION
[0046] 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.
[0047] 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.
[0048] Table 1 shows a list of the elements of the method.
Referring to FIG. 1 showing a schematic of an embodiment of the
apparatus. This apparatus comprises a pressurized vessel or reactor
2, which is implemented in a vertical position. In another
embodiment, the reactor can be spherical in shape. The vertical
position is not limiting or mandatory and other embodiments with
less than a 90 degree angle with the horizontal can be implemented.
In operation, the pressure vessel 2 is charged with aggregate 1. A
feed input system 4 and a materials output system 3 provides for
feeding aggregate and removal of spent aggregate from the pressure
vessel 2. In one embodiment, the pressure vessel 2 is fitted with
rapid release ends so that the input feed material can be fed into
and the spent material removed rapidly from the pressure vessel 2
during operation. This rapid open-close embodiment allows an almost
continuous operation to occur in field practice with a plurality of
pressure vessels 2 clustered together. An oxidizer 12a is injected
into the reactor 2 from the oxidizer system supply 12b. Accessory
systems necessary to condense and separate the products of the
reaction are attached to the reactor 2. These include solids
separator 5, condenser 6, separator 7, another condenser 8, another
separator 9, and a flare system 10 and necessary piping system 11.
An additional supply system 12c for a combustible fluid 12d is part
of the apparatus and connected to the reactor 2.
[0049] Referring to FIG. 1, the solid tar sand or oil shale
material is crushed to form an aggregate 1. The aggregate 1 which
is nominally about 1 inch sized particles, is introduced into the
reactor vessel 2 by means of the input materials handling system 4.
Naturally occurring in the aggregate 1 is the pure hydrocarbon
material 27 as shown in FIG. 3 where the sand grains 26 are coated
with connate water 28 and surrounded by the solid hydrocarbon 27
either bitumen in the case of sands or kerogen in the case of
shales. In this invention, the term hydrocarbon refers to any of
the typical solid hydrocarbon derivatives found in the oil shales,
tar sands and heavy oil deposits worldwide.
[0050] 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.
[0051] Referring to FIG. 2, which shows a schematic of some of the
invention elements, an igniter device 13 and an igniter pack 14 are
present in the lower portion of the pressure vessel 2. In one
embodiment the igniter device 13 can be an electric arc type device
like a spark plug like apparatus. In one embodiment, a plurality of
igniter devices 13, operatively placed in the reactor, can be used
to accomplish the initiation of the combustion process. The igniter
pack 14 can be small quantity of highly combustible material, which
improves the combustibility of the hydrocarbon 27 and allows the
combustion front to propagate rapidly. After the pressure vessel 2
is filled with the charge of hydrocarbon aggregate 1, the required
quantity of oxidizer 12a is injected into the pressure vessel 2
from the oxidizer supply 12b. The igniter 13 is activated and
ignites the igniter pack 14. The oxidizer 12a can be injected
either before the igniter 13 is activated or after the igniter 13
is activated. In the case where the oxidizer is injected before
igniter activation the burn rate is initially faster than in the
case when the oxidizer is injected after the ignition is initiated.
The igniter pack 14 facilitates and initiates the combustion of the
hydrocarbon 27 in the pressure vessel 2. The additional small
quantity of fuel 12d which permeates the aggregate pack helps the
combustion process. The combustion propagates vertically and
horizontally in the pressure vessel 2 as a fraction of the
hydrocarbon burns producing considerable exothermic heat and
raising the temperature and pressure inside the pressure vessel 2.
This propagation of the combustion front is shown in FIG. 9.
[0052] 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.
[0053] Referring to FIG. 4 which shows an idealized cross-section
of an aggregate particle, as the hydrocarbon 27 is combusted inside
the reactor 2, the pressure and temperature rises inside the
reactor 2 and the hot gases 36 penetrate the surface 41 of the
aggregate particle 1 and at the microscopic level the difference in
pressures between the hot high pressure gas 36 and the low pressure
zones 39 and 40 inside the aggregate material allow the hot
products of combustion to completely penetrate the solid aggregate
1. On contacting the hot gases 36 generated by the combustion
process the water film 28 surrounding the sand grains 26 shown in
FIG. 3 rapidly evaporate creating a dispersion effect on the solid
hydrocarbon 27 which helps the aggregate particle 1 to disintegrate
into a fine distribution of sand and hydrocarbon. The unburnt
hydrocarbon 27 goes through a pyrolysis stage and change of phase
and the vaporized and pyrolized material now occupies the
interstitial pore spaces in the aggregate 1. The result of the
combustion process is the formation of gaseous combustion products
and heated hydrocarbon which has now undergone a substantial
chemical and physical change.
[0054] 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.
[0055] 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.
[0056] In another embodiment of the invention, referring to FIG. 2,
a fluid circulating system comprising a pump or compressor device
15, a fluid supply 16, and a plurality of pipes 17, is used after
the combustion step to circulate a drive fluid through the pressure
vessel 2 in the direction 18 shown. The drive fluid, which can be
any gaseous fluid and preferably the combustion products
themselves, is used to scavenge the hydrocarbon products which have
undergone chemical and physical changes during the thermal process.
This scavenging process is similar to a cycling gas drive process,
illustrated in Ref. 1, which is a common practice in enhanced oil
recovery in the petroleum industry. In a gas cycling process dry
natural gas is injected into and repeatedly circulated through the
reservoir rock system to increase the oil recovery by enriching the
oil components in the produced gas stream. The cycled gas
repeatedly picks up more and more liquid oil components from the
native hydrocarbons in the pore space traversed by the circulating
gas. Since in each circulation of fluid the oil components are
entrained from the aggregate particle surfaces, the free pore
spaces and are added to the flowing gas stream, the required number
of pore volumes of drive fluids to circulate is determined either
empirically or from a series of chemical process calculations.
After the required circulation time which normally involves less
than 100 pore volumes requiring less than 15 minutes, the enriched
combustion products containing the hydrocarbon vapors are then
vented to the condensation system beginning at the solid trap 5. In
this embodiment the gas is circulated either upward or downward in
the reactor device.
[0057] A further embodiment to the invention is shown in FIGS. 5,
6, and 7 in which a vertical combustion tunnel 34 is implemented in
the center of the aggregate material 1 in the pressure vessel 2.
This combustion tunnel 34 which is essentially a vertical void or
space, can be implemented in a variety of shapes is shown as a
"star" in cross-section in FIG. 5. This implementation is similar
in principle and function to the vertical axial tunnel used in
solid rocket booster motors shown in Ref. 2, in which the rocket
fuel burns more uniformly, rapidly and efficiently along the
vertical axis and also across the horizontal axis. The
implementation of the tunnel 34 as shown shortens the distance
traveled by the combustion front as it moves horizontally across
the aggregate material 1. FIG. 9 shows the movement of the
combustion front as it consumes the hydrocarbon material 27 in the
aggregate 1 by successively burning through the solid material away
from the central combustion tunnel 34. The combustion tunnel 34
allows uniform controlled burn, it also allows a rapid burn since
the combustion front has to move radially only a few inches in the
horizontal direction outward from the central axis of the pressure
vessel 2, rather than vertically a distance of several feet if the
burn were initiated from the base of the pressure vessel only and
front movement was limited to planar movement from the base of the
vessel upwards. A further embodiment of the combustion tunnel is
implemented by utilizing a fuel pack 37, shown in FIG. 8, which is
a consumable pack comprising a combustion accelerator which is
operatively placed in the combustion tunnel 34. The accelerator
material is used to help maximize the combustion process throughout
the aggregate column. Typical accelerants can be solid, liquid or
gels which can burn rapidly and uniformly across the total axis of
the fuel pack. A further embodiment of the invention involves the
implementation of a plurality of vertical combustion tunnels 34 in
the reactor 2, this embodiment will be most beneficial in reactors
that have large areal cross-sections.
[0058] 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 FIG. 1 a hydrogen supply system 44
comprising compressors and piping to allow high-pressure hydrogen
to be injected into the pressure vessel 2 containing the combusting
mixture. The hydrogen is injected after the combustion process is
completed and the hydrocarbon has undergone a phase change. At the
reactor high temperature, the vaporized hydrocarbon can react more
effectively with the injected hydrogen to upgrade the hydrocarbons
produced from the aggregate material.
[0059] Another embodiment of the invention is shown in FIGS. 10 and
11 in which the wall of the pressure vessel 2 is modified by a
composite sheath construction. This composite construction allows
the vessel to maintain required vessel strength, to lower vessel
construction costs, and to increase the economic benefits of the
oil recovery operation. As shown in FIG. 10 the pressure vessel 2
is wrapped in a high strength fiber sheath 29 similar to that used
the construction of a high pressure gas cylinder for SCUBA diving
or for compressed natural gas (CNG) fuel storage. In these two
instances, the working pressures of the composite material
cylinders are far in excess of 3,000 psi. As shown in FIG. 11
another modification of the pressure vessel 2 is the utilization of
reinforced concrete sheath 31 around the pressure vessel 2 to
increase the strength of the composite vessel. The use of a
composite sheath for the pressure vessel 2 minimizes cost of
manufacture without sacrificing the strength or integrity of the
vessel.
[0060] Another embodiment of the invention is shown in FIG. 12
which illustrates a cooling system comprising a coolant reservoir
19, a cooling jacket and associated piping 20, a pump 21, a heat
exchanger 22. A plurality of pressure vessels 2 are implemented as
a cluster and surrounded by a common cooling jacket 20. During the
operation of the invention, coolant fluid 23, 24, 25 is circulated
around the pressure vessels to remove the sensible heat and lower
the wall temperatures of the pressure vessels 2. Lowering of the
vessel wall temperatures increases the operational pressures of the
pressure vessels 2 since at higher temperatures the tensile
strength of the steel decreases.
[0061] In one embodiment of the invention, the heat energy stored
in the hot spent aggregate at the output feed system 3 shown in
FIG. 1 is used to preheat the incoming aggregate feed 1 by the use
of an air heated exchanger system in which the hot air generated
off the spent aggregate preheats the incoming aggregate through a
pre-heater system 45. This pre-heating phase raises the aggregate
feed temperature and at the same time decreases the fraction of
water in the aggregate material by evaporating and vaporizing part
of the in-situ water as the temperature is raised. Since the latent
heat of vaporization is a significant component to the heat
requirements of the reactor process, decreasing the water content
lowers the heat requirements, and thus the amount of hydrocarbon
which is required to be burnt to complete the reaction in the
pressure vessel 2. This approach increases the economics of
operation of the invention since more oil is recovered from the
aggregate.
[0062] 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
[0063] 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 [0064] 2
Solid Rocket Booster Engines Design,
http://en.wikipedia.org/wiki/Solid-rocket. [0065] 3. SPE 35392,
"Combustion/Oxidation Behavior of Athabasca Oil Sands Bitumen",
Society of Petroleum Engineers, Dallas Tex. www.spe.org [0066] 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 [0067] 5. "Pressurised Fluidised Reactor",
www.energy.kth.se/proj/projects/SUSPOWER/Downloads/Pressurized%20fluidize-
d%20bed%20reactor.pdf [0068] 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. [0069] 7. "Oil sand and Oil Shale Chemistry",
Otto P. Strausz and Elizabeth M Lown., Verlag Chemie, NY. Weinhem
1978. ISBN 0-89573-102-9 [0070] 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.
[0071] 9. "Oil Sands Fuel of the Future", L. V. Hills, Editor,
McAra printing, Calgary, Canada. 1974. TABLE-US-00001 TABLE 1 Item
List No Description 1 Hydrocarbon containing aggregate 2 Pressure
Vessel 3 Spent Feed system 4 Input Feed system 5 Solid Trap 6 Air
cooled Condenser 7 Heavy oil Separator 8 Liquid Cooled Condenser 9
Light Oil Separator 10 Gas Vent 11 Collection system 12a Oxidizer
12b Oxidizer Supply 12c Supplemental Fuel Supply 12d Supplemental
Fuel 13 Ignition Device 14 Igniter pack 15 Circulating Pump 16
Fluid Supply 17 Circulating pipes 18 Direction of flow 19 Coolant
reservoir 20 Cooling Jacket 21 Pump 22 Heat Exchanger 23 Coolant
Fluid 24 Hot Coolant 25 Cold Coolant 26 Sand Grain 27 Solid
Hydrocarbon e.g Bitumen 28 Connate Water 29 Reinforced Fibre
wrapping 30 Reinforcing bar in cement sheath 31 Cement Sheath 32
Initial Combustion Front 33 Late Stage Combustion Front 34
Combustion Tunnel 35 Cross-section Line 36 Hot Combustion Gases 37
Fuel Pack 38 Outer high pressure zone 39 Intermediate pressure zone
40 Inner low pressure zone 41 Surface of aggregate particle 42
Direction of hot gas flow into aggregate 43 Combustion Products 44
Hydrogen Supply 45 Aggregate Preheater system
[0072] TABLE-US-00002 TABLE 2 BITUMEN ENERGY BALANCE Quantity Units
Basis 1 Ton 2,000 lbs Percent - Bitumen 13% Percent -Water 3%
Bitumen in 1 Ton 260 lbs Bitumen-Heat Value 18,486 BTU/Lb Sand in 1
Ton 1680 Lbs Water in 1 Ton 60 Lbs Heat Transfer Efficiency -% 90%
Re-Heat Transfer Efficiency -% 70% Sand Density 110 lb/ft3 Bitumen
Sp Cr 1.0077 Bitumen Density 62.88 Ib/ft3 Bitumen Fraction 0.13
Heat Capacity water 1.00 Btu/lb/F. Latent Heat Steam 1180 BTU/Lb
Bitumen Sp. Heat Capacity 0.35 Btu/lb/F. Sand Sp. Heat Capacity
0.19 Btu/lb/F. Overall Sp. Heat Capacity 0.2108 Btu/lb/F. Heat
Required per ton Material to Boiling 470.2 BTU Pt. Overall Sp. Heat
Capacity to Boiling Pt 0.2351 Btu/lb/F. Heat Required per ton to
vaporize water 70,800 BTU Process Variables On 1 Ton Basis: 2,000
Bitumen Burnt 10.00% Weight Bitumen-lb 26 Heat Produced-Btu
(Available) 480,636 Heat for Latent Vaporization (Approximate)
70,800 Heat Available for sensible changes. 409,836 Weight Sand +
Bitumen + Water lb 2000 Total Heat Capacity - Btu/F. 470.2 Heat
Transfer Efficiency -% 90% Temperature Rise - F. 784 Ambient temp -
F. 65 Temperature Level of Material -F. 849 Temperatures Needed
Melting Pt - C. 350 Temperatures Needed - F. 662 Overheat Degrees -
F. 187 Remaining Bitumen - Lbs 234 Remaining Sand - Lbs 1,680
Temperature Difference to Ambient - F. 784 Residual Heat in Sand -
BTU 250,399 Re-Heat Transfer Efficiency -% 70% Heat Transferred to
incoming Material - 175,279 BTU Heat to Vaporize incoming water -
BTU 70,800 Heat to raise bitumen, sand, water - BTU 104,479
Temperature Rise - F. 222 Temperature of Incoming PreHeated Aggre-
287 gate - F.
* * * * *
References