U.S. patent application number 12/509298 was filed with the patent office on 2011-01-27 for system and method for converting material comprising bitumen into light hydrocarbon liquid product.
Invention is credited to Willem P.C. Duyvesteyn.
Application Number | 20110017642 12/509298 |
Document ID | / |
Family ID | 43496369 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110017642 |
Kind Code |
A1 |
Duyvesteyn; Willem P.C. |
January 27, 2011 |
SYSTEM AND METHOD FOR CONVERTING MATERIAL COMPRISING BITUMEN INTO
LIGHT HYDROCARBON LIQUID PRODUCT
Abstract
Various methods and systems for obtaining light hydrocarbon
distillate from material comprising bitumen are disclosed. The
method may include a primary leaching or extraction process that
separates most of the bitumen from the material comprising bitumen
and results in a bitumen-enriched solvent phase and first
solvent-wet tailings. The bitumen-enriched solvent phase includes
mainly solvent and bitumen. The bitumen-enriched solvent phase is
injected into a nozzle reactor wherein at least a portion of the
bitumen is cracked into light hydrocarbon distillate. The light
hydrocarbon distillate may then be used as solvent in the first
primary leaching or extraction step.
Inventors: |
Duyvesteyn; Willem P.C.;
(Reno, NV) |
Correspondence
Address: |
HOLLAND & HART, LLP
P.O BOX 8749
DENVER
CO
80201
US
|
Family ID: |
43496369 |
Appl. No.: |
12/509298 |
Filed: |
July 24, 2009 |
Current U.S.
Class: |
208/390 |
Current CPC
Class: |
Y02E 50/10 20130101;
C10G 9/00 20130101; C10G 21/003 20130101; Y02E 50/13 20130101; B01J
2219/0011 20130101; C10G 1/04 20130101; B01J 2219/00006 20130101;
B01J 19/26 20130101 |
Class at
Publication: |
208/390 |
International
Class: |
C10G 1/04 20060101
C10G001/04 |
Claims
1. A method comprising: forming a first mixture by mixing a first
quantity of material comprising bitumen with a first solvent,
wherein the first mixture comprises a bitumen-enriched solvent
phase; separating the bitumen-enriched solvent phase from the first
mixture and thereby producing first solvent-wet tailings, wherein
the bitumen-enriched solvent phase comprises a bitumen component
and the first solvent-wet tailings comprise a first solvent
component; forming a light hydrocarbon liquid distillate and a
non-participating hydrocarbon stream by cracking bitumen component
inside a first nozzle reactor; and mixing the light hydrocarbon
liquid distillate with a second quantity of material comprising
bitumen.
2. The method as claimed in claim 1, further comprising: separating
the first solvent component from the first solvent-wet tailings by
adding a second solvent to the first solvent-wet tailings and
thereby producing second solvent-wet tailings, wherein the second
solvent-wet tailings comprise a second solvent component; and
separating the second solvent component from the second solvent-wet
tailings.
3. The method as recited in claim 1, wherein separating the
bitumen-enriched solvent phase from the first mixture comprises: a
first stage of separating a first quantity of the bitumen-enriched
solvent phase from the first mixture by filtering, settling or
draining the bitumen-enriched solvent phase from the first mixture;
and a second stage of separating a second quantity of the
bitumen-enriched solvent phase from the first mixture by adding a
second quantity of first solvent to the first mixture.
4. The method as recited in claim 3, wherein the second stage of
separating a second quantity of the bitumen-enriched solvent phase
from the first mixture comprises washing the first mixture with the
second quantity of first solvent in a countercurrent process.
5. The method as recited in claim 2, wherein separating the first
solvent component from the first solvent-wet tailings comprises
washing the first solvent-wet tailings with the second solvent in a
countercurrent process.
6. The method as recited in claim 2, wherein separating the second
solvent from the second solvent-wet tailings comprises flashing the
second solvent component from the second solvent-wet tailings.
7. The method as recited in claim 1, wherein separating the
bitumen-enriched solvent phase from the first mixture comprises
filtering the first mixture in a plate and frame-type filter
press.
8. The method as recited in claim 2, wherein separating the first
solvent component from the first solvent-wet tailings comprises
adding the second solvent to the first solvent-wet tailings loaded
in a plate and frame-type filter press.
9. The method as recited in claim 7, wherein filtering the first
mixture in a plate and frame-type filter press further comprises
adding a gas over the first mixture loaded in the plate and
frame-type filter press.
10. The method as recited in claim 8, wherein gas is added over the
first solvent-wet tailings loaded in the plate and frame-type
filter press.
11. The method as claimed in claim 1, further comprising: cracking
the non-participating hydrocarbon stream inside a second nozzle
reactor.
12. The method as claimed in claim 1, wherein the material
comprising bitumen is tar sands.
13. The method as claimed in claim 1, wherein the first solvent
comprises a light aromatic solvent.
14. The method as claimed in claim 13, wherein the light aromatic
solvent comprises kerosene, diesel, gas oil, naphtha, benzene,
toluene, an aromatic alcohol, derivatives thereof, or a combination
thereof.
15. The method as claimed in claim 2, wherein the second solvent
comprises a volatile hydrocarbon solvent.
16. The method as claimed in claim 15, wherein the volatile
hydrocarbon solvent comprises a cyclo- or iso-paraffin having
between 3 and 9 carbons, derivatives thereof, or combinations
thereof.
17. The method as claimed in claim 2, wherein the second solvent is
liquefied petroleum gas.
18. The method as claimed in claim 1, wherein the first nozzle
reactor comprises: a reactor body having an interior reactor
chamber with an injection end and an ejection end; an injection
passage mounted in the nozzle reactor in material injecting
communication with the injection end of the interior reactor
chamber, the injection passage having (a) an enlarged volume
injection section, an enlarged volume ejection section, and a
reduced volume mid-section intermediate the enlarged volume
injection section and enlarged volume ejection section, (b) a
material injection end, and (c) a material ejection end in
injecting communication with the interior reactor chamber; and a
material feed passage penetrating the reactor body and being (a)
adjacent to the material ejection end of the injection passage and
(b) transverse to an injection passage axis extending from the
material injection end to the material ejection end in the
injection passage.
19. The method as claimed in claim 1, wherein the light hydrocarbon
liquid distillate comprises hydrocarbon having a molecular weight
less than 300 Daltons.
20. The method as claimed in claim 1, wherein cracking bitumen
component inside the first nozzle reactor comprises: injecting a
stream of cracking material through an injection passage into an
interior reactor chamber; and injecting the bitumen component into
the interior reactor chamber adjacent to the injection passage and
transverse to the stream of cracking material entering the interior
reactor chamber from the injection passage.
21. The method of claim 1, further comprising: separating the
bitumen-enriched solvent phase into bitumen component and a first
solvent phase prior to cracking the bitumen component inside a
first nozzle reactor.
22. The method of claim 21, wherein separating the bitumen-enriched
solvent phase into bitumen component and the first solvent phase
comprises heating the bitumen-enriched solvent phase to a
temperature above the boiling point temperature of the first
solvent.
23. A method comprising: forming a first mixture by mixing a first
quantity of material comprising bitumen with a first solvent,
wherein the first mixture comprises a bitumen-enriched solvent
phase; separating the bitumen-enriched solvent phase from the first
mixture and thereby producing first solvent-wet tailings, wherein
the bitumen-enriched solvent phase comprises a bitumen component
and a primary first solvent component and the first solvent-wet
tailings comprise a secondary first solvent component; separating
the primary first solvent from the bitumen-enriched solvent phase
to thereby isolate the bitumen component of the bitumen-enriched
solvent phase; producing an asphaltene stream by deasphalting
bitumen component; forming a light hydrocarbon liquid distillate
and a non-participating hydrocarbon stream by cracking the
asphaltene stream inside a first nozzle reactor; and mixing the
light hydrocarbon liquid distillate with a second quantity of
material comprising bitumen.
24. The method as claimed in claim 23, further comprising:
separating the secondary first solvent component from the first
solvent-wet tailings by adding a second solvent to the first
solvent wet tailings and thereby producing second solvent-wet
tailings, wherein the second solvent-wet tailings comprise a second
solvent component; and separating the second solvent component from
the second solvent-wet tailings.
25. The method as recited in claim 23, wherein separating the
bitumen-enriched solvent phase from the first mixture comprises: a
first stage of separating a first quantity of the first
bitumen-enriched solvent phase from the first mixture by filtering,
settling or draining the bitumen-enriched solvent phase from the
first mixture; and a second stage of separating a second quantity
of the first bitumen-enriched solvent phase from the first mixture
by adding a second quantity of first solvent to the first
mixture.
26. The method as recited in claim 25, wherein the second stage of
separating the second quantity of the first bitumen-enriched
solvent phase from the first mixture comprises washing the first
mixture with the second quantity of first solvent in a
countercurrent process.
27. The method as recited in claim 24, wherein separating the first
solvent component from the first solvent-wet tailings comprises
washing the first solvent-wet tailings with the second solvent in a
countercurrent process.
28. The method as recited in claim 24, wherein separating the
second solvent from the second solvent-wet tailings comprises
flashing the second solvent component from the second solvent-wet
tailings.
29. The method as recited in claim 23, wherein separating the
bitumen-enriched solvent phase from the first mixture comprises
filtering the first mixture in a plate and frame-type filter
press.
30. The method as recited in claim 24, wherein separating the first
solvent component from the first solvent-wet tailings comprises
adding second solvent to the first solvent-wet tailings loaded in a
plate and frame-type filter press.
31. The method as recited in claim 29, wherein filtering the first
mixture in a plate and frame-type filter press further comprises
adding a gas over the first mixture loaded in the plate and
frame-type filter press.
32. The method as recited in claim 30, wherein gas is added over
the first solvent-wet tailings loaded in the plate and frame-type
filter press.
33. The method as claimed in claim 23, further comprising: cracking
the non-participating hydrocarbon inside a second nozzle
reactor.
34. The method as claimed in claim 23, wherein the material
comprising bitumen is tar sands.
35. The method as claimed in claim 23, wherein the first solvent
comprises a light aromatic solvent.
36. The method as claimed in claim 35, wherein the light aromatic
solvent comprises kerosene, diesel, gas oil, naphtha, benzene,
toluene, an aromatic alcohol, derivatives thereof, or a combination
thereof.
37. The method as claimed in claim 24, wherein the second solvent
comprises a volatile hydrocarbon solvent.
38. The method as claimed in claim 37, wherein the volatile
hydrocarbon solvent comprises a cyclo- or iso-paraffin having
between 3 and 9 carbons, derivatives thereof, or combinations
thereof.
39. The method as claimed in claim 24, wherein the second solvent
is liquefied petroleum gas.
40. The method as claimed in claim 23, wherein the first nozzle
reactor comprises: a reactor body having an interior reactor
chamber with an injection end and an ejection end; an injection
passage mounted in the nozzle reactor in material injecting
communication with the injection end of the interior reactor
chamber, the injection passage having (a) an enlarged volume
injection section, an enlarged volume ejection section, and a
reduced volume mid-section intermediate the enlarged volume
injection section and enlarged volume ejection section, (b) a
material injection end, and (c) a material ejection end in
injecting communication with the interior reactor chamber; a
material feed passage penetrating the reactor body and being (a)
adjacent to the material ejection end of the injection passage and
(b) transverse to a injection passage axis extending from the
material injection end to the material ejection end in the
injection passage.
41. The method as claimed in claim 23, wherein the light
hydrocarbon liquid distillate comprises hydrocarbon having a
molecular weight less than 300 Daltons.
42. The method as claimed in claim 23, wherein cracking the
asphaltene stream inside the first nozzle reactor comprises:
injecting a stream of cracking material through a injection passage
into an interior reactor chamber; and injecting the asphaltene
stream into the interior reactor chamber adjacent to the injection
passage and transverse to the stream of cracking material entering
the interior reactor chamber from the injection passage.
43. The method as recited in claim 23, wherein separating the first
solvent from the bitumen-enriched solvent phase comprises heating
the bitumen-enriched solvent phase to a temperature above the
boiling point temperature of the first solvent.
44. A method comprising: solvent extracting a first quantity of
material comprising bitumen with at least one solvent to separate
bitumen from the first quantity of material comprising bitumen;
cracking the bitumen to form a light hydrocarbon liquid distillate;
and solvent extracting a second quantity of material comprising
bitumen with the light hydrocarbon distillate to separate bitumen
from the second quantity of material comprising bitumen.
45. A method comprising: mixing a first solvent with a first
quantity of material comprising bitumen; separating a
bitumen-enriched solvent phase from a first result of mixing the
first solvent with the first quantity of material comprising
bitumen; feeding the bitumen-enriched solvent phase through a
nozzle reactor; and mixing a portion of a second result of feeding
the bitumen-enriched solvent phase through a nozzle reactor with a
second quantity of material comprising bitumen.
46. The method as recited in claim 45, wherein separating the
bitumen-enriched solvent phase from the first result of mixing the
first solvent with the first quantity of material comprising
bitumen comprises: filtering, settling or draining a first quantity
of bitumen-enriched solvent phase from the first result of mixing
the first solvent with the first quantity of material comprising
bitumen; displacing a second quantity of bitumen-enriched solvent
phase from the first result of mixing the first solvent with the
first quantity of material comprising bitumen.
47. The method as claimed in claim 45, wherein the first solvent
comprises a light aromatic solvent.
48. The method as claimed in claim 45, wherein the portion of the
second result comprises light hydrocarbon distillate.
49. A method comprising: mixing a first quantity of material
comprising bitumen with a first solvent; separating a
bitumen-enriched solvent phase from a first result of mixing the
first solvent with the first quantity of material comprising
bitumen; separating a first solvent component from the
bitumen-enriched solvent phase; deasphalting a second result of
separating the first solvent component from the bitumen-enriched
solvent phase; feeding a third result of deasphalting the second
result into a nozzle reactor; and mixing a portion of a fourth
result of feeding the third result into a nozzle reactor with a
second quantity of material comprising bitumen.
50. The method as claimed in claim 49, wherein the first solvent
comprises a light aromatic solvent.
51. The method as claimed in claim 49, wherein the portion of the
fourth result comprises light hydrocarbon distillate.
52. The method as claimed in claim 1, further comprising: upgrading
bitumen component of the bitumen-enriched solvent phase.
53. The method as claimed in claim 23, further comprising:
upgrading bitumen component of the bitumen-enriched solvent phase.
Description
BACKGROUND
[0001] Bitumen is an extremely heavy type of crude oil that is
often found in naturally occurring geological materials such as tar
sands, black shales, coal formations, and weathered hydrocarbon
sources contained in sandstones and carbonates. Bitumen may be
described as flammable brown or black mixtures or tar-like
hydrocarbons derived naturally or by distillation from petroleum.
Bitumen can be in the form of a viscous oil to a brittle solid,
including asphalt, tars, and natural mineral waxes. Substances
containing bitumen may be referred to as bituminous, e.g.,
bituminous coal, bituminous tar, or bituminous pitch. At room
temperature, the flowability of bitumen is much like cold molasses.
Bitumen may be processed to yield oil and other commercially useful
products, primarily by cracking the bitumen into lighter
hydrocarbon material. A comparison between the properties of
Athabasca-type bitumen and an average crude oil is presented in the
following table.
TABLE-US-00001 Property (typical) Bitumen Crude Oil Specific
gravity - g/cc 1.05 0.85 Viscosity @ 38 deg C. - cp 750,000 <200
Carbon - % 83 86 Hydrogen - % 10.5 13.5 H/C mol ratio 1.5 1.9
Sulfur 5.0 <0.5 C5 asphaltenes - % 17 <5 Resins - % 34 <20
Aromatics - % 34 >30 Saturates - % 15 >35 Conradson carbon -
% 15 <5
[0002] As noted above, tar sands represent one of the well known
sources of bitumen. Tar sands typically include bitumen, water and
mineral solids. The mineral solids can include inorganic solids
such as coal, sand, and clay. Tar sand deposits can be found in
many parts of the world, including North America. One of the
largest tar sands deposits is in the Athabasca region of Alberta,
Canada. In the Athabasca region, the tar sands formation can be
found at the surface, although it may be buried as deep as two
thousand feet below the surface overburden. Tar sands deposits are
measured in barrels equivalent of oil. It is estimated that the
Athabasca tar sands deposit contains the equivalent of about 1.7 to
2.3 trillion barrels of oil. Global tar sands deposits have been
estimated to contain up to 4 trillion barrels of oil. By way of
comparison, the proven worldwide oil reserves are estimated to be
about 1.3 trillion barrels.
[0003] The bitumen content of tar sands varies from approximately 3
wt % to 21 wt %, with a typical content of approximately 12 wt %.
As such, an initial step in deriving oil and other commercially
useful products from bitumen typically requires extracting the
bitumen from the naturally occurring geological material. In the
case of tar sands, this may include separating the bitumen from the
mineral solids and other components of tar sands.
[0004] One conventional process includes mixing the tar sands ore
with hot water to form a bitumen enriched froth. The froth is
separated and further processed to isolate the bitumen product.
Conventional water-based extraction technologies are capable of
separating bitumen from higher grade ore but are unable to
economically separate bitumen from lower grade ore. Unfortunately,
this means that a significant amount of tar sand ore is not capable
of being processed to recover the otherwise valuable bitumen.
[0005] Another problem with conventional water based extraction
technologies is the low overall recovery rate of bitumen.
Unfortunately, some conventional extraction processes discharge
part of the bitumen in the ore with the tailings. Other
conventional processes discharge a significant part of the bitumen
in the ore as an asphaltene precipitate with the tailings. Not only
does this reduce the efficiency of the extraction process due to
lower recoveries, but it also presents potential environmental
problems that must be addressed.
[0006] Many conventional methods for obtaining bitumen from tar
sands also have serious technical limitations. For example, many
conventional methods use water, which can cause clays in the tar
sands to swell and interfere with processing equipment. In
addition, some conventional methods result in the undesirable
precipitation of soluble asphaltenes.
[0007] One example of a conventional method is described in U.S.
Pat. No. 4,046,668 (the '668 patent). The '668 patent discloses the
extraction of hydrocarbons from tar sands with a mixture of light
naphtha having from 5 to 9 carbon atoms per molecule and methanol.
The method disclosed in the '668 patent is limited, in part,
because it requires the simultaneous use of two solvents, which
increases processing costs and is less efficient in terms of
bitumen recovery and solvent plus bitumen content of the final
tailings that are disposed.
[0008] U.S. Pat. No. 4,347,118 (the '118 patent) discloses a method
in which pentane is used to extract bitumen from tar sands. The
method disclosed in the '118 patent requires the use of two
fluidized bed drying zones. Operation of these fluidized bed drying
zones requires a large amount of energy, limiting the efficiency of
the overall method. Furthermore, the pentane solvent does not
solubilize the asphaltene fraction of the bitumen that is not
pentane soluble. Thus, this fraction of the bitumen is discharged
with the tailings. For Athabasca type bitumen, this may range from
20 wt % to 40 wt % of the total initial hydrocarbon content of the
tar sands.
[0009] U.S. Pat. No. 5,143,598 (the '598 patent) discloses a method
that includes adding heptane to tar sands to form a bitumen-rich
heptane phase and then displacing the bitumen-rich heptane phase
with water. This method utilizes steam vaporization and
condensation, which are low-efficiency processes. Also, the use of
heptane, a non-aromatic solvent, in this method can result in the
precipitation of the heptane insoluble asphaltene fraction present
in the bitumen phase. The heptane insoluble asphaltene fraction is
discharged with the tailings. In addition, using water not only
generates large amounts of aqueous waste but also creates oil-water
emulsions that are very difficult to breakdown. The use of water
can also introduce undesirable impurities into bitumen, such as
chlorine, and can result in undesirable swelling of clays in the
tar sands. Furthermore, the bitumen recovered by this method
typically has a low purity and requires additional processing, such
as by centrifugation. This further increases the cost of the
overall recovery process.
[0010] The above issues may be mitigated or eliminated by
separating bitumen from a material comprising bitumen by using a
two step extraction process as disclosed in co-pending U.S.
application Ser. Nos. 12/041,554 and 11/249,234, both of which are
incorporated herein by reference in their entireties. The method
generally comprises a first extraction step wherein material
comprising bitumen is mixed with a first solvent, and the resulting
mixture is separated into a bitumen-enriched solvent phase and
first solvent-wet tailings. The majority of the bitumen in the
material comprising bitumen is contained in the bitumen-enriched
solvent phase. The first solvent may be, for example, a light
aromatic solvent. The bitumen-enriched solvent phase may then
undergo a further separation wherein the bitumen is separated from
the first solvent. In a second extraction step, the first
solvent-wet tailings are mixed with a second solvent, and the
resulting mixture is separated into a first solvent-enriched second
solvent phase and second solvent-wet tailings. The majority of the
first solvent in the first solvent-wet tailings are contained in
the first solvent-enriched second solvent phase. The second solvent
may be a volatile hydrocarbon solvent. The second solvent-wet
tailings are then treated to remove any most, if not all, of the
second solvent contained therein. The bitumen obtained from the
bitumen-enriched solvent phase may then be subjected to further
processing to upgrade the material into useful fuel products.
[0011] As can be seen from the above description, this two-step
extraction process requires various supplies of solvents in order
to carry out the separation of bitumen from material comprising
bitumen. Typically, the solvents will need to be obtained from a
third party, thus increasing the overall cost of the process and
making the manufacturing process dependent on an outside vendor.
Factors such as these will tend to inflate the price of oil derived
from material comprising bitumen according to the two step
extraction process.
SUMMARY
[0012] Disclosed are embodiments of a method and system for
obtaining light hydrocarbon liquid distillate from material
comprising bitumen. The disclosed method and system may include one
or more solvent extraction steps to separate bitumen from the
material comprising bitumen, a cracking step for cracking bitumen
inside a nozzle reactor, and a recycling step to use the light
hydrocarbon liquid distillate produced from cracking the bitumen in
the nozzle reactor as the solvent in at least one of the extraction
steps. In some embodiments, such a method and system may thereby
become an essentially solvent free and self-sustaining method and
system.
[0013] In some embodiments, a method includes forming a first
mixture by mixing a first quantity of material comprising bitumen
with a first solvent. The first mixture includes a bitumen-enriched
solvent phase. The method also includes separating the
bitumen-enriched solvent phase from the first mixture. Separation
of the bitumen-enriched solvent phase results in the first mixture
becoming first solvent-wet tailings. The bitumen-enriched solvent
phase includes bitumen component and the first solvent-wet tailings
include a first solvent component. The method also includes forming
a light hydrocarbon liquid distillate and a non-participating
hydrocarbon stream by cracking the bitumen component of the
bitumen-enriched solvent phase in a first nozzle reactor. The
method can also include mixing the light hydrocarbon distillate
with a second quantity of material comprising bitumen.
[0014] In some embodiments, a method includes forming a first
mixture by mixing a first quantity of material comprising bitumen
with a first solvent. The first mixture includes a bitumen-enriched
solvent phase. The method also includes separating the
bitumen-enriched solvent phase from the first mixture. Separation
of the bitumen-enriched solvent phase results in the first mixture
becoming first solvent-wet tailings. The bitumen-enriched solvent
phase includes a bitumen component and a primary first solvent
component, and the first solvent-wet tailings include a first
solvent component. The method also includes separating the primary
first solvent from the bitumen-enriched solvent phase. Separation
of the primary solvent from the bitumen-enriched solvent phase
results in the isolation of the bitumen component of the
bitumen-enriched solvent phase. The method can further include
producing an asphaltene stream by deasphalting the bitumen
component. The method may also include forming a light hydrocarbon
liquid distillate and a non-participating hydrocarbon stream by
cracking the asphaltene stream in a first nozzle reactor. Further,
the method can also include mixing the light hydrocarbon distillate
with a second quantity of material comprising bitumen.
[0015] In some embodiments, a method includes solvent extracting a
first quantity of material comprising bitumen with at least one
solvent to separate bitumen from the first quantity of material
comprising bitumen. The method also includes cracking the separated
bitumen to form a light hydrocarbon liquid distillate. The method
can also include solvent extracting a second quantity of material
comprising bitumen with the light hydrocarbon liquid distillate to
separate bitumen from the second quantity of material comprising
bitumen.
[0016] In some embodiment, a method includes mixing a first
quantity of material comprising bitumen with a first solvent. The
method also includes separating a bitumen-enriched solvent phase
from a first result of mixing the first solvent with the first
quantity of material comprising bitumen. Additionally, the method
includes separating a first solvent component from the
bitumen-enriched solvent phase. The method can also include
deasphalting a second result of separating the first solvent
component from the bitumen-enriched solvent phase. Furthermore, the
method includes feeding a third result of deasphalting the second
result into a nozzle reactor. The method also includes mixing a
portion of a fourth result of feeding the third result into a
nozzle reactor with a second quantity of material comprising
bitumen.
[0017] In some embodiments, a method includes mixing a first
quantity of material comprising bitumen with a first solvent. The
method can also include separating a bitumen-enriched solvent phase
from a first result of mixing the first solvent with the first
quantity of material comprising bitumen. The method can also
include separating a first solvent component from the
bitumen-enriched solvent phase. The method further includes
deasphalting a second result of separating the first solvent
component from the bitumen-enriched solvent phase. Additionally,
the method includes feeding a third result of deasphalting the
second result into a nozzle reactor. Furthermore, the method
includes mixing a portion of a fourth result of feeding the third
result into a nozzle reactor with a second quantity of material
comprising bitumen.
[0018] It is to be understood that the foregoing is a brief summary
of various aspects of some disclosed embodiments. The scope of the
disclosure need not therefore include all such aspects or address
or solve all issues noted in the background above. In addition,
there are other aspects of the disclosed embodiments that will
become apparent as the specification proceeds.
[0019] The foregoing and other features, utilities, and advantages
of the subject matter described herein will be apparent from the
following more particular description of certain embodiments as
illustrated in the accompanying drawings. In this regard, it is to
be understood that the scope of the invention is to be determined
by the claims as issued and not by whether given subject includes
any or all features or aspects noted in this Summary or addresses
any issues noted in the Background.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The preferred and other embodiments are disclosed in
association with the accompanying drawings in which:
[0021] FIG. 1 is a flow chart depicting a method for obtaining
bitumen;
[0022] FIG. 2 is a cross-section view of one embodiment of a nozzle
reactor;
[0023] FIG. 3 is a flow chart depicting a method for obtaining
bitumen;
[0024] FIG. 4 is a schematic diagram of a system and method for
obtaining bitumen;
[0025] FIG. 5 is a schematic diagram of a system and method for
obtaining bitumen;
[0026] FIG. 6 is a schematic diagram of a system and method for
obtaining bitumen; and
[0027] FIG. 7 is a schematic diagram of a system and method for
obtaining bitumen;
DETAILED DESCRIPTION
[0028] Before describing the details of the various embodiments
herein, it should be appreciated that the terms "solvent," "a
solvent" and "the solvent" include one or more than one individual
solvent compound unless expressly indicated otherwise. Mixing
solvents that include more than one individual solvent compounds
with other materials can include mixing the individual solvent
compounds simultaneously or serially unless indicated otherwise. It
should also be appreciated that the term "tar sands" includes oil
sands. The separations described herein can be partial, substantial
or complete separations unless indicated otherwise. All percentages
recited herein are weight percentages unless indicated
otherwise.
[0029] Tar sands are used throughout this disclosure as a
representative material comprising bitumen. However, the methods
and system disclosed herein are not limited to processing of tar
sands. Any material comprising bitumen may be processed by the
methods and systems disclosed herein.
[0030] As shown in FIG. 1, a first embodiment of a method for
obtaining bitumen from material comprising bitumen includes a first
step 100 of mixing a first quantity of material comprising bitumen
with a first solvent to form a first mixture including a
bitumen-enriched solvent phase, a step 110 of separating the
bitumen enriched solvent phase from the first mixture and thereby
producing first solvent-wet tailings, a step 120 of cracking the
bitumen component of the bitumen-enriched solvent phase inside a
first nozzle reactor to form a light hydrocarbon liquid distillate
and a non-participating hydrocarbon stream, and a step 130 of
mixing the light hydrocarbon liquid distillate with a second
quantity of material comprising bitumen.
[0031] Step 100 of mixing a first quantity of material comprising
bitumen with a first solvent to form a first mixture represents a
solvent extraction step (also sometimes referred to as dissolution,
solvation, or leaching). Solvent extraction is a process of
separating a substance from a material by dissolving the substance
of the material in a liquid. In this situation, the material
comprising bitumen is mixed with one or more solvents to dissolve
bitumen in the solvent and thereby separate it from the other
components of the material comprising bitumen (e.g., the mineral
solids of tar sands).
[0032] The first solvent used in mixing step 100 may include a
hydrocarbon solvent. Any suitable hydrocarbon solvent or mixture of
hydrocarbon solvents that is capable of dissolving bitumen may be
used. In certain embodiments, the hydrocarbon solvent is a
hydrocarbon solvent that does not cause asphaltene precipitation.
The hydrocarbon solvent or mixture of hydrocarbon solvents can be
economical and relatively easy to handle and store. The hydrocarbon
solvent or mixture of hydrocarbon solvents may also be generally
compatible with refinery operations.
[0033] In some embodiments, the first solvent may be a light
aromatic solvent. The light aromatic solvent may be an aromatic
compound having a boiling point temperature less than about
400.degree. C. at atmospheric pressure. In certain embodiments, the
light aromatic solvent used in the first mixing step is an aromatic
having a boiling point temperature in the range of from about
75.degree. C. to about 350.degree. C. at atmospheric pressure, and
more specifically, in the range of from about 100.degree. C. to
about 250.degree. C. at atmospheric pressure.
[0034] It should be appreciated that the light aromatic need not be
100% aromatic compounds. Instead, the light aromatic solvent may
include a mixture of aromatic and non-aromatic compounds. For
example, the first solvent can include greater than zero to about
100 wt % aromatic compounds, such as approximately 10 wt % to 100
wt % aromatic compounds, or approximately 20 wt % to 100 wt %
aromatic compounds. In one example, the aromatic compounds include
naphthalenes and/or cyclo-alkanes. A general chemical formula for
cyclo-alkanes is C.sub.nH.sub.2(n+1-g), where n is the number of C
atoms and g is the number of rings in the molecule.
[0035] Any of a number of suitable aromatic compounds may be used
as the first solvent. Examples of aromatic compounds that can be
used as the first solvent include benzene, toluene, xylene,
aromatic alcohols and combinations and derivatives thereof. The
first solvent can also include compositions, such as kerosene,
diesel (including biodiesel), gas oil (e.g., light gas oil (gas oil
having boiling point temperature in the range of from 200.degree.
C. to 300.degree. C.) or medium light gas oil (gas oil having
boiling point temperature in the range of from 240.degree. C. to
350.degree. C.)), light distillate (distillate having boiling point
temperature in the range of from 140.degree. C. to 260.degree. C.),
commercial aromatic solvents such as Solvesso 100, Solvesso 150,
and Solvesso 200 (also known in the U.S.A. as Aromatic 100, 150,
and 200, including mainly C.sub.10-C.sub.11 aromatics, and produced
by ExxonMobil), and/or naphtha. Naphtha, for example, is
particularly effective at dissolving bitumen and is generally
compatible with refinery operations. Some examples of kerosene
include hydrocarbons having between 9 and 15 carbons per molecule.
Some examples of diesel include hydrocarbons having between 15 and
25 carbons per molecule. Some examples of light or medium light gas
oil include hydrocarbons having between 13 and 20 carbons per
molecule. Some examples of naphtha include hydrocarbons having
between 4 and 12 carbons per molecule. These examples are not
intended to limit the general meanings of the respective terms.
[0036] The material comprising bitumen used in the mixing step may
be any material that includes bitumen. In certain embodiments, the
material comprising bitumen includes any material including 3 wt %
or more of bitumen. Exemplary materials comprising bitumen include,
but are not limited to, tar sands, black shales, coal formations,
and weathered hydrocarbon sources contained in sandstones and
carbonates. The material comprising bitumen may be obtained by any
known means for obtaining material comprising bitumen, such as by
surface mining, underground mining, or any in situ extraction
methods, such as vapor extraction (Vapex) and steam assisted
gravity drainage (SAGD) extraction, and other solvent and thermal
extraction techniques.
[0037] The step 100 of mixing a first quantity of material
comprising bitumen and a first solvent can be performed as a
continuous, batch, or semi-batch process. Continuous processing is
typically used in larger scale implementations. However, batch
processing may result in more complete separations than continuous
processing.
[0038] The material comprising bitumen and the first solvent may be
mixed by any suitable manner for mixing two materials for any
suitable period of time. The mixing 100 of the material comprising
bitumen and the first solvent is preferably carried out to the
point of dissolving most, if not all, of the bitumen contained in
the material comprising bitumen. In certain embodiments, the
material comprising bitumen and the first solvent are mixed in a
vessel to dissolve the bitumen and form the first mixture. The
vessel can be selectively opened or closed. The vessel used for
mixing may also contain mechanisms for stirring and mixing solvent
and material comprising bitumen to further promote dissolution of
the bitumen in the first solvent. For example, powered mixing
devices such as a rotating blade may be provided to mix the
contents of the vessel. The vessel may also rotate about its axis
to provide mixing, such as in a ball mill, or may be a grinding
mill, such as described in U.S. Pat. No. 5,512,008.
[0039] The presence of water in the material comprising bitumen may
impact the amount of power to be used when mixing the first solvent
and material comprising bitumen to dissolve the bitumen in the
first solvent. Material comprising bitumen may include from about 2
wt % to about 10 wt % water, and excessive mixing with the first
solvent can result in the formation of certain water-solvent
emulsions that can be quite stable. By controlling the amount of
power used when mixing and the mixing time, the water content of
the material comprising bitumen will stay associated with the
non-bitumen components of the material comprising bitumen. Any
mixing regime that produces a Reynolds number in excess of 10,000
would likely result in the formation of certain water-solvent
emulsions. Additionally, it is expected that with tar sand clumps
of 3 inches or less, the mixing time should be limited to less than
30 minutes to avoid emulsion formation.
[0040] In certain embodiments, material comprising bitumen and the
first solvent are mixed by virtue of the manner in which the
material comprising bitumen and the first solvent are introduced
into the vessel. In this regard, the first solvent may be
introduced into a vessel already containing material comprising
bitumen at a high velocity, thereby effectively agitating and
mixing the contents of the vessel. Conversely, the material
comprising bitumen may be introduced into a vessel already
containing first solvent. In some embodiments, the first solvent
and material comprising bitumen are jointly introduced into a
rotating mill with a ball charge or a non-rotating vibratory mill
with charge of grinding or mixing media.
[0041] The amount of the first solvent added to the material
comprising bitumen is a sufficient amount to effectively dissolve
at least a portion, or desirably all, of the bitumen in the
material comprising bitumen. In some embodiments, the amount of the
first solvent mixed with the material comprising bitumen is
approximately 0.5 to 3.0 times the amount of bitumen by volume
contained in the material comprising bitumen, approximately 0.6 to
2.0 times the amount of the bitumen by volume contained in the
material comprising bitumen, or approximately 0.75 to 1.5 times the
amount of bitumen by volume contained in the material comprising
bitumen.
[0042] It should be noted that the ratio of the first solvent to
bitumen is affected by the amount of bitumen in the material
comprising bitumen. For example, when the material comprising
bitumen is a high grade tar sands ore (e.g., greater than 12 wt %
bitumen), the high grade tar sands ore can be processed with a
solvent to bitumen weight ratio as low as 2:1. However lower grade
tar sands ore (e.g., 6 wt % bitumen) may be processed with a
solvent to bitumen ratio greater than 3:1 to provide sufficient
liquid to fill up the open space between the particles.
[0043] The first mixture of the first solvent and the material
comprising bitumen generally results in the formation of a
bitumen-enriched solvent phase within the first mixture, with the
majority of the bitumen from the material comprising bitumen
dissolved in the bitumen-enriched solvent phase. In certain
embodiments, 90%, preferably 95%, and most preferably 99% or more
of the bitumen in the material comprising bitumen is dissolved in
the first solvent and becomes part of the bitumen-enriched solvent
phase.
[0044] Step 100 of mixing first solvent and material comprising
bitumen may be performed at any suitable temperature and pressure.
In certain embodiments, it may be desirable to perform the mixing
step at an increased pressure to maintain the first solvent as a
liquid during the mixing. Additionally, performing the mixing step
at higher temperatures may allow for the use of a wider range of
suitable first solvents (e.g., aromatic solvents having a boiling
point temperature higher than 400.degree. C.). Mixing at elevated
temperatures may also enhance the kinetics of the dissolution
process.
[0045] In step 110, the bitumen-enriched solvent phase is separated
from the first mixture, Separation of the bitumen-enriched solvent
phase from the first mixture results in the first mixture becoming
first solvent-wet tailings. Any suitable process for separating the
bitumen-enriched solvent phase from the first mixture may be used,
such as by filtering (including pressure and vacuum filtration),
settling and decanting, or by gravity or gas overpressure
drainage.
[0046] Separation of the bitumen-enriched solvent phase preferably
does not include the separation of the water content of the first
mixture. Because the water is heavier than the first solvent
(specific gravity of 1 for water versus specific gravity of
.about.0.8 for first solvent), the water will likely not be removed
from the first mixture when the bitumen-enriched solvent phase is
separated by the method disclosed above.
[0047] In certain embodiments, the bitumen-enriched solvent phase
removed from the first mixture includes from about 5 wt % to about
50 wt % of bitumen and from about 50 wt % to about 95 wt % of the
first solvent. The bitumen-enriched solvent phase includes little
or no non-bitumen components of the material comprising bitumen
(e.g., mineral solids). The first solvent-wet tailings created by
removing the bitumen-enriched solvent phase from the first mixture
may include from about 75 wt % to about 95 wt % non-bitumen
components of the material comprising bitumen and from about 5 wt %
to about 25 wt % first solvent. The first solvent component of the
first solvent-wet tailings represents first solvent mixed with the
material comprising bitumen but which is not removed from the first
mixture during separation step 110. This first solvent component of
the first solvent-wet tailings may have bitumen dissolved therein.
Accordingly, in certain embodiments, the first solvent-wet tailings
may include from about 50 wt % to about 99 wt % of bitumen.
[0048] The vessel for mixing mentioned previously may function as
both the mixer and a separator for separating the bitumen-enriched
solvent phase from the first mixture. Alternatively, separate
vessels can be used for mixing and separating, wherein the first
mixture is transported from the mixing vessel to a separation
vessel. In certain embodiments, the vessel may be divided into
sections. One section may be used to mix the material comprising
bitumen and the first solvent and another section may be used to
separate the bitumen-enriched solvent phase and the first
solvent-wet tailings.
[0049] The separation of the bitumen-enriched solvent phase from
the first mixture can be performed as a continuous, batch, or
semi-batch process. Continuous processing is typically used in
larger scale implementations. However, batch processing may result
in more complete separations than continuous processing.
[0050] Separation of the bitumen-enriched solvent phase from the
first mixture by any of the above-described methods may be preceded
or followed by applying pressurized gas over the first mixture.
Applying a pressurized gas over the first mixture facilitates the
separation of the bitumen-enriched solvent phase from the
non-bitumen components of the first solvent-wet tailings. Liberated
bitumen-enriched solvent phase can then be removed by applying
additional first solvent to the first solvent-wet tailings as
described in greater detail below. The addition of additional first
solvent can, in some embodiments, displace the liberated
bitumen-enriched solvent phase from the first solvent-wet tailings.
Applying a pressurized gas over the first mixture may also provide
a driving force for moving bitumen-enriched solvent phase out of
the first mixture without the need for adding additional first
solvent. Any suitable gas may be used. In certain embodiments, the
gas is nitrogen, carbon dioxide or steam. The gas may also be added
over the first mixture in any suitable amount. In certain
embodiments, 62.5 ft.sup.3 to 375 ft.sup.3 of gas per ton of
material comprising bitumen is used. This is equivalent to a range
of about 4.5 liters to 27 liters of gas per liter of material
comprising bitumen. In some embodiments, 125 ft.sup.3 of gas per
ton of material comprising bitumen is used.
[0051] In certain embodiments, the bitumen-enriched solvent phase
is separated from the first mixture by filtering the first mixture
with a plate and frame-type filter press. Any plate and frame-type
filter press known to those of ordinary skill in the art may be
used. An exemplary plate and frame-type filter press suitable for
use in this method is described in U.S. Pat. No. 4,222,873.
Generally, the first mixture is pumped into frame chamber located
between two filter plates. The first mixture fills the frame
chamber and the liquid component of the first mixture migrates out
of the frame chamber through the filter cloths of each filter
plate, thereby separating the liquid component of the first mixture
from the solid component of the first mixture. In this case, the
liquid component is the bitumen-enriched solvent phase (i.e., first
solvent having bitumen dissolved therein) and the solids component
is the first solvent-wet tailings. The bitumen-enriched solvent
phase that has passed out of the frame chamber is routed out of the
plate and frame-type filter press while the first solvent-wet
tailings are left behind in the frame chamber.
[0052] When utilizing a plate and frame-type filter press to
separate the first mixture, pressurized gas may be injected into
the frame chamber after the frame chamber has been filled with the
first mixture to promote the separation of the bitumen-enriched
solvent phase from mineral solids in the first mixture and the
displacement of the bitumen-enriched solvent phase from the first
mixture. The introduction of pressurized gas into the frame chamber
may proceed according to the details provided above for applying
pressurized gas over a first mixture.
[0053] In certain embodiments, step 110 includes a second
separation stage in addition to the separation described above.
When the bitumen-enriched solvent phase is removed from the first
mixture, a residual amount of bitumen-enriched solvent phase may
remain in the first mixture. Because the first mixture includes a
residual amount of bitumen-enriched solvent phase, the first
mixture is now considered first solvent-wet tailings. Accordingly,
the second separation stage is performed to remove the residual
bitumen-enriched solvent phase from the first solvent-wet
tailings.
[0054] The second separation stage may be performed by adding a
second quantity of first solvent to the first solvent-wet tailings.
The addition of a second quantity of first solvent displaces the
residual bitumen-enriched solvent phase and thereby forces the
residual bitumen-enriched solvent phase out of the first
solvent-wet tailings. Some of the second quantity of the first
solvent may remain in the first solvent-wet tailings, but little to
no bitumen-enriched solvent phase remains. In this manner, the
first solvent-wet tailings remain first solvent-wet tailings even
after the second stage of separation, although the first
solvent-wet tailing become essentially bitumen-free.
[0055] Any suitable amount of first solvent may be added to the
first solvent-wet tailings in order to displace the
bitumen-enriched solvent phase. In certain embodiments, the second
quantity of first solvent is added to the first solvent-wet
tailings in an amount of from about 10% to about 200% of the first
quantity of first solvent mixed with the material comprising
bitumen. The second quantity of first solvent may also be added to
the first solvent-wet tailings in any suitable fashion. For
example, where the first solvent-wet tailings remain loaded in the
frame chamber of a plate and frame-type filter press as described
above, the second quantity of first solvent may be added to the
frame chamber to displace the residual bitumen-enriched solvent
phase out of the first-solvent wet tailings and through the filter
screens on either side of the filter chamber.
[0056] The second quantity of first solvent may be the same first
solvent as used in step 100 of mixing first solvent with the
material comprising bitumen. Alternatively, the second quantity of
first solvent may be a different solvent from the first quantity of
first solvent. However, the second quantity of first solvent is
still of the type of first solvents described in greater detail
above (e.g., a light aromatic solvent).
[0057] The residual bitumen-enriched solvent phase displaced from
the first solvent-wet tailings includes predominantly bitumen and
first solvent. In certain embodiments, the residual
bitumen-enriched solvent phase includes from about 5 wt % to about
50 wt % bitumen and from about 50 wt % to about 95 wt % first
solvent. Little to no non-bitumen components of the material
comprising bitumen is present in the residual bitumen-enriched
solvent phase. After removal of the residual bitumen-enriched
solvent phase, the first solvent-wet tailings include little or no
bitumen. In certain embodiments, the first solvent-wet tailings
include from 0 wt % to about 2 wt % bitumen, from about 2 wt % to
about 15 wt % first solvent, and from about 83 wt % to about 98 wt
% non-bitumen components.
[0058] The residual bitumen-enriched solvent phase collected from
the second separation stage may be combined with the
bitumen-enriched solvent phase collected from the first separation
stage prior to any further processing conducted on the
bitumen-enriched solvent phase.
[0059] In some embodiments, the second separation stage is carried
out by washing the first solvent-wet tailings with the second
quantity of first solvent in a countercurrent process. The
countercurrent process generally includes moving the first
solvent-wet tailings in one direction while passing the second
quantity of first solvent through the first solvent-wet tailings in
an opposite direction. For example, the first solvent-wet tailings
may be loaded at the bottom of a screw classifier conveyor
positioned at an incline, while second quantity of first solvent is
introduced at the top of the screw classifier conveyor. An
exemplary screw classifier conveyor suitable for use in this method
is described in U.S. Pat. No. 2,666,242. As the screw classifier
conveyor moves the first solvent-wet tailings upwardly, the second
quantity of first solvent flows down the inclined screw classifier
conveyor and passes through the first solvent-wet tailings. The
second quantity of first solvent displaces any residual
bitumen-enriched solvent phase contained in the first solvent-wet
tailings, thereby "washing" the bitumen from the first solvent-wet
tailings.
[0060] Separation of the residual bitumen-enriched solvent phase
and the first solvent-wet tailings naturally occurs based on the
configuration of the screw classifier conveyor, with the
predominantly liquid residual bitumen-enriched solvent phase
collecting at one end of the washing unit and the predominantly
solid first solvent-wet tailings at the opposite end of the washing
unit. For example, when an inclined screw classifier conveyor is
used, the residual bitumen-enriched solvent phase will collect at
the bottom of the screw classifier conveyor, while the first
solvent-wet tailings will collect at the top of the screw
classifier conveyor. The residual bitumen-enriched solvent phase
includes predominantly bitumen and first solvent. In certain
embodiments, the residual bitumen-enriched solvent phase includes
from about 5 wt % to about 50 wt % bitumen and from about 50 wt %
to about 95 wt % first solvent. The bitumen-enriched solvent phase
may include relatively minor amounts of non-bitumen components of
the material comprising bitumen. The first solvent-wet tailings
include predominantly first solvent and non-bitumen components of
the material comprising bitumen. The first solvent component of the
first solvent-wet tailings is first solvent that does not pass all
the way through the first solvent-wet tailings in the
countercurrent washing process. In certain embodiments, the first
solvent-wet tailings includes from about 5 wt % to about 20 wt %
first solvent and from about 80 wt % to about 95 wt % non-bitumen
components (e.g., mineral solids). The first solvent-wet tailings
may include no bitumen, especially in the case where additional
quantities of first solvent are added to the first solvent-wet
tailings as described in greater detail below.
[0061] The countercurrent process may include multiple stages. For
example, after a first pass of first solvent through the first
solvent-wet tailings, the resulting residual bitumen-enriched
solvent phase may be passed through the first solvent-wet tailings
several more times. Alternatively, additional quantities of fresh
first solvent may be passed through the first solvent-wet tailings
one or more times. In this manner, the residual bitumen-enriched
solvent phase or fresh quantities of first solvent become
progressively more enriched with bitumen after each stage and the
first solvent-wet tailings lose progressively more bitumen after
each stage.
[0062] Another suitable process for separating the bitumen-enriched
solvent phase from the first solvent includes loading the first
mixture in a vertical column and injecting a second quantity of
first solvent into the first mixture. More specifically, the second
quantity of first solvent is injected into the first material at a
top end of the vertical column such that the second quantity of
first solvent passes through the first material and displaces the
bitumen-enriched solvent phase included in the first material. The
injection of the second quantity of first solvent results in the
bitumen-enriched solvent phase exiting the vertical column at the
bottom end of the vertical column where it may be collected.
[0063] Any method of loading the first mixture in the vertical
column may be used. First mixture may be poured into the vertical
column or, when an appropriate first mixture viscosity is obtained
during the mixing of the first solvent and the material comprising
bitumen, the first mixture may be pumped into the vertical column.
First mixture is generally loaded in the vertical column by
introducing the first mixture into the column at the top end of the
vertical column. The bottom end of the vertical column is blocked,
such as by a removable plug or by virtue of the bottom end of the
vertical column resting against the floor. In certain embodiments,
a metal filter screen at the bottom end of the vertical column is
used to maintain the first mixture in the vertical column. As such,
introducing first mixture at the top end of the vertical column
fills the vertical column with first mixture. The amount of first
mixture loaded in the vertical column may be such that the first
mixture substantially fills the vertical column with first mixture.
In certain embodiments, first mixture is added to the vertical
column to occupy 90% or more of the volume of the vertical column.
In certain embodiments, the first mixture is not filled to the top
of the vertical column so that room is provided to inject first
solvent, second solvent, etc., into the vertical column.
[0064] The vertical orientation of the vertical column includes
aligning the column substantially perpendicular to the ground, but
also includes orientations where the column forms angles less than
90.degree. with the ground. The column may generally be oriented at
any angle that results in gravity aiding the flow of the first
solvent, second solvent, etc., from one end of the column to the
other. In certain embodiments, the column is oriented at an angle
anywhere within the range of from about 1.degree. to 90.degree.
with the ground. In a preferred embodiment, the column is oriented
at an angle anywhere within the range of from about 15.degree. to
90.degree. with the ground.
[0065] The material of the vertical column is also not limited. Any
material that will hold the first mixture within the vertical
column may be used. The material is also preferably a non-porous
material such that various liquids injected into the vertical
column may only exit the column from one of the ends of the
vertical column. The material may be a corrosive resistant material
so as to withstand the potentially corrosive components of the
first mixture loaded in the column as well as any potentially
corrosive materials injected into the vertical column.
[0066] The shape of the vertical column is not limited to a
specific configuration in all embodiments. Generally speaking, the
vertical column has two ends opposite one another, designated a top
end and a bottom end. The cross-section of the vertical column may
be any shape, such as a circle, oval, square or the like. The
cross-section of the vertical column may change along the height of
the column, including both the shape and size of the vertical
column cross-section. The vertical column may be a straight line
vertical column having no bends or curves along the height of the
vertical column. Alternatively, the vertical column may include one
or more bends or curves.
[0067] Various dimensions may be used for the vertical column,
including the height, inner cross sectional diameter and outer
cross sectional diameter of the vertical column. In certain
embodiments, the ratio of height to inner cross sectional diameter
may range from 0.5:1 to 15:1.
[0068] The second quantity of first solvent may be injected into
the vertical column by any suitable method. In certain embodiments,
the second quantity of first solvent is poured into the vertical
column at the top end and allowed to flow down through the first
mixture loaded therein under the influence of gravity.
[0069] The amount of first solvent added to the first mixture is
not limited. The amount is preferably enough first solvent to
displace most or all of the dissolved bitumen content of the first
mixture. In certain embodiments, the second quantity of first
solvent added to the first mixture is from about 1.25 to about 2.25
times the amount of bitumen by volume in the original material
comprising bitumen.
[0070] Upon injection into the first mixture, the first solvent
flows downwardly through the height of the column via small void
spaces in the first mixture. The first solvent may flow downwardly
through the force of gravity or by an external force applied to the
vertical column. Examples of external forces applied include the
application of pressure from the top of the vertical column or the
application of suction at the bottom of the vertical column.
[0071] In certain embodiments, the addition of first solvent is
carried out under flooded conditions. In other words, more first
solvent is added to the top of the vertical column than what flows
down through the first mixture, thereby creating a head of solvent
at the top of the vertical column.
[0072] In certain embodiments, the bitumen-enriched solvent exiting
the vertical column includes from about 10 wt % to about 60 wt %
bitumen and from about 40 wt % to about 90 wt % first solvent.
Minor amounts of non-bitumen material may also be included in the
bitumen-enriched solvent phase. In certain embodiments, 95% or more
of the bitumen is removed from the first mixture.
[0073] Various methods of collecting the bitumen-enriched solvent
may be used, such as by providing a collection vessel at the bottom
end of the vertical column. The bottom end of the vertical column
may include a metal filter screen having a mesh size that does not
permit first mixture to pass through but which does allow for
bitumen-enriched solvent to pass through and collect in a
collection vessel located under the screen. Collection of
bitumen-enriched solvent may be carried out for any suitable period
of time. In certain embodiments, collection is carried out for 2 to
30 minutes.
[0074] After injecting a second quantity of first solvent and
collecting the bitumen-enriched solvent at the bottom of the
vertical column, additional quantities of first solvent may be
added to the vertical column to extract additional bitumen from the
first mixture. Repeating the addition of first solvent and
collecting the resultant bitumen-enriched solvent phase may
increase the overall extraction rate of bitumen from the first
mixture. In certain embodiments, the use of multiple first solvent
injection steps results in removing 99% or more of the bitumen in
the first mixture.
[0075] After separating the bitumen-enriched solvent phase from the
first mixture, a further step 120 may take place to crack at least
a portion of the bitumen component of the bitumen-enriched solvent
phase inside a nozzle reactor. Cracking of the bitumen can produce
a light hydrocarbon liquid distillate.
[0076] Nozzle reactors include any type of apparatus wherein
differing types of materials are injected into an interior reactor
chamber of the nozzle reactor for the purpose of seeking to cause
the materials to interact within the interior reactor chamber and
achieve alteration of the mechanical or chemical composition of one
or more of the materials. In the instant embodiment, the
bitumen-enriched solvent phase is injected into the interior
reactor chamber of the nozzle reactor along with a cracking
material, wherein the two materials interact to crack the bitumen
component of the bitumen-enriched solvent phase and produce lighter
hydrocarbon material.
[0077] Various types of nozzle reactor suitable for cracking
hydrocarbons such as bitumen may be used. In certain embodiments,
the nozzle reactor is a nozzle reactor as disclosed in co-pending
U.S. application Ser. No. 11/233,385, hereby incorporated by
reference in its entirety. The nozzle reactor of U.S. application
Ser. No. 11/233,385 may generally include an interior reactor
chamber, an injection passage, and a material feed passage. The
interior reactor chamber includes an injection end and an ejection
end. The injection passage is mounted in the nozzle reactor in
material injecting communication with the injection end of the
interior reactor chamber. The injection passage has an enlarged
volume injection section, an enlarged volume ejection section, and
a reduced volume mid-section intermediate the enlarged volume
injection section and enlarged volume ejection section. The
injection passage also has a material injection end and a material
ejection end, with the material ejection end being in injecting
communication with the interior reactor chamber. The material feed
passage penetrates the interior reactor chamber and is generally
located adjacent to the material ejection end of the injection
passage. Additionally, the material feed passage is aligned so as
to be transverse to the axis of the injection passage axis
extending from the material injection end to the material ejection
end in the injection passage.
[0078] FIG. 2 illustrates a nozzle reactor disclosed in U.S.
application Ser. No. 11/233,385 that is suitable for use in this
embodiment. The nozzle reactor, indicated generally at 10, has a
reactor body injection end 12, a reactor body 14 extending from the
reactor body injection end 12, and an ejection port 13 in the
reactor body 14 opposite its injection end 12. The reactor body
injection end 12 includes an injection passage 15 extending into
the interior reactor chamber 16 of the reactor body 14. The central
axis A of the injection passage 15 is coaxial with the central axis
B of the interior reactor chamber 16.
[0079] The injection passage 15 has a circular diametric
cross-section and, as shown in the axially-extending
cross-sectional view of FIG. 2, opposing inwardly curved side wall
portions 17, 19 (i.e., curved inwardly toward the central axis A of
the injection passage 15) extending along the axial length of the
injection passage 15. In certain embodiments, the axially inwardly
curved side wall portions 17, 19 of the injection passage 15 allow
for a higher speed of injection gas when passing through the
injection passage 15 into the interior reactor chamber 16.
[0080] The side wall of the injection passage 15 can provide one or
more among: (i) uniform axial acceleration of cracking material
passing through the injection passage; (ii) minimal radial
acceleration of such material; (iii) a smooth finish; (iv) absence
of sharp edges; and (v) absence of sudden or sharp changes in
direction. The side wall configuration can render the injection
passage 15 substantially isentropic.
[0081] A material feed passage 18 extends from the exterior of the
reactor body 14 toward the interior reaction chamber 16
transversely to the axis B of the interior reactor chamber 16. The
material feed passage 18 penetrates an annular material feed port
20 adjacent the interior reactor chamber wall 22 at the interior
reactor chamber injection end 24 abutting the reactor body
injection end 12. The material feed port 20 includes an annular,
radially extending reactor chamber feed slot 26 in
material-injecting communication with the interior reactor chamber
16. The material feed port 20 is thus configured to inject feed
material: (i) at about a 90.degree. angle to the axis of travel of
cracking material injected from the injection passage 15; (ii)
around the entire circumference of a cracking material injected
through the injection passage 15; and (iii) to impact the entire
circumference of the free cracking material stream virtually
immediately upon its emission from the injection passage 15 into
the interior reactor chamber 16.
[0082] The annular material feed port 20 may have a U-shaped or
C-shaped cross-section among others. In certain embodiments, the
annular material feed port 20 may be open to the interior reactor
chamber 16, with no arms or barrier in the path of fluid flow from
the material feed passage 18 toward the interior reactor chamber
16. The junction of the annular material feed port 20 and material
feed passage 18 can have a radiused cross-section.
[0083] The interior reactor chamber 16 can be bounded by stepped,
telescoping side walls 28, 30, 32 extending along the axial length
of the reactor body 14. In certain embodiments, the stepped side
walls 28, 30, 32 are configured to: (i) allow a free jet of
injected cracking material, such as superheated steam, natural gas,
carbon dioxide, or other gas, to travel generally along and within
the conical jet path C generated by the injection passage 15 along
the axis B of the interior reactor chamber 16, while (ii) reducing
the size or involvement of back flow areas, e.g., 34, 36, outside
the conical or expanding jet path C, thereby forcing increased
contact between the high speed cracking material jet stream within
the conical jet path C and feed material, such as heavy
hydrocarbons, injected through the annular material feed port
20.
[0084] As indicated by the drawing gaps 38, 40 in the embodiment of
FIG. 2, the reactor body 14 has an axial length (along axis B) that
is much greater than its width. In the FIG. 2 embodiment, exemplary
length-to-width ratios are typically in the range of 2 to 7 or
more.
[0085] The dimensions of the various components of the nozzle
reactor shown in FIG. 2 are not limited, and may generally be
adjusted based on the amount of material feed to be cracked inside
the nozzle reactor. Table 1 provides exemplary dimensions for the
various components of the nozzle reactor based on the hydrocarbon
input in barrels per day (BPD).
TABLE-US-00002 TABLE 1 Material Feed Input (BPD) Nozzle Reactor
Component (mm) 5,000 10,000 20,000 Injection Passage, Enlarged
Volume 148 207 295 Injection Section Diameter Injection Passage,
Reduced Volume 50 70 101 Mid-Section Diameter Injection Passage,
Enlarged Volume 105 147 210 Ejection Section Diameter Injection
Passage Length 600 840 1,200 Interior Reactor Chamber Injection 187
262 375 End Diameter Interior Reactor Chamber Ejection 1,231 1,435
1,821 End Diameter Interior Reactor Chamber Length 6,400 7,160
8,800 Overall Nozzle Reactor Length 7,000 8,000 10,000 Overall
Nozzle Reactor Outside 1,300 1,600 2,000 Diameter Overall Nozzle
Reactor Length to 5.4 5.0 5.0 Outside Diameter Ratio
[0086] As used in the method of this embodiment, the nozzle reactor
is generally operated by injecting bitumen-enriched solvent phase
into the interior reactor chamber 16 via the material feed passage
18. At least a portion of the bitumen-enriched solvent phase,
including at least a portion of the bitumen component, is injected
into the reactor body passage 16 is in a liquid phase. The
bitumen-enriched solvent phase may be pretreated prior to injection
into the interior reactor chamber 16 in order to alter the amount
or fraction of bitumen-enriched solvent phase that is in a liquid
phase. In certain embodiments, the temperature and/or pressure of
the bitumen-enriched solvent phase is adjusted to alter the amount
of bitumen-enriched solvent phase in the liquid phase prior to
injection. The non-liquid portion of the bitumen-enriched solvent
phase is typically injected into the interior reactor chamber 16 in
a gaseous phase.
[0087] As the bitumen-enriched solvent phase is injected into the
interior reactor chamber 16, a cracking material is injected into
the interior reactor chamber 16 by way of the injection passage 15.
The configuration of the injection passage 15 is such that the
cracking material is accelerated to a supersonic speed and enters
the interior reactor chamber 16 at supersonic speed. Shock waves
are produced by the cracking material traveling at supersonic
speeds, and the shock waves crack the largest hydrocarbon molecules
present in the bitumen component of the bitumen-enriched solvent
phase entering the interior reactor chamber 16 via the material
feed passage 18. In this manner, bitumen may be broken down into
lighter hydrocarbon molecules.
[0088] In certain embodiments, about 10% to about 95% of the
bitumen injected into the interior reactor chamber 16 is cracked
and broken down into lighter hydrocarbon products. The cracking of
bitumen produces hydrocarbons having lower molecular weight than
the bitumen. In certain embodiments, the bitumen is broken down
into light hydrocarbon liquid distillate. The light hydrocarbon
liquid distillate includes hydrocarbons having a molecular weight
less than about 300 Daltons. In certain embodiments, about 30% to
about 60% of the bitumen cracked inside the interior reactor
chamber 16 is cracked into light hydrocarbon liquid distillate.
[0089] Other portions of the bitumen-enriched solvent phase (e.g.,
lower molecular weight molecules) injected into the interior
reactor chamber 16 may pass through the nozzle reactor without
being cracked. Often, some fraction of the bitumen-enriched solvent
phase that is injected into the interior reactor chamber 16 may
pass through the nozzle reactor uncracked because of kinetic
limitations. These portions of the bitumen-enriched solvent phase
may be referred to as non-participating hydrocarbon, since the
shock waves produced by the injection of the cracking material
through the injection passage 15 do not act on this material to
crack it into lighter hydrocarbon material. Bitumen that is cracked
but not cracked into light hydrocarbon distillate may also be
referred to as non-participating hydrocarbon. In certain
embodiments, about 40% to about 70% of the bitumen injected into
the interior reactor chamber 16 is not cracked and exits the nozzle
reactor as non-participating hydrocarbon.
[0090] In certain embodiments, the light hydrocarbon distillate and
the non-participating hydrocarbon exiting the nozzle reactor may be
transported to a separation unit that separates the hydrocarbon
distillate from the non-participating hydrocarbon. The separation
unit may be any suitable separator capable of separating the two
streams. Examples of suitable separation units include, but are not
limited to, distillation units, vacuum towers, gravity separation
units, filtration units, and cyclonic separation units.
[0091] In certain embodiments, the non-participating hydrocarbon
stream that exits the nozzle reactor and is separated from the
light hydrocarbon distillate may be subjected to further processing
to upgrade the non-participating hydrocarbon into useful material.
Various types of processing may be performed on the
non-participating hydrocarbon for upgrading the non-participating
hydrocarbon. In one example, the non-participating hydrocarbon is
injected into a second nozzle reactor or recycled back into the
first nozzle reactor. Where the non-participating hydrocarbon is
injected into a second nozzle reactor, the structure of the second
nozzle reactor may be similar or identical to the first nozzle
reactor described in greater detail above. The dimensions of the
second nozzle reactor may be identical to the dimensions of the
first nozzle reactor, or the dimensions of the second nozzle
reactor may be scaled up or down from the dimensions of the first
nozzle reactor. The non-participating hydrocarbon stream may also
be pretreated prior to injecting the hydrocarbon stream into the
second nozzle reactor in order to alter the amount of
non-participating hydrocarbon entering the second nozzle reactor in
the liquid phase. Such further treatment of non-participating
hydrocarbon is discussed in greater detail in co-pending U.S.
application Ser. No. 12/466,923.
[0092] Not all of the bitumen component of the bitumen-enriched
solvent phase need be cracked in a nozzle reactor to produce light
hydrocarbon distillate. A portion of the bitumen may be upgraded.
Upgrading of the bitumen may comprise any processing that generally
produces a stable liquid (i.e., synthetic crude oil) and any
subsequent refinement of synthetic crude oil into petroleum
products. The process of upgrading bitumen to synthetic crude oil
may include any processes known to those of ordinary skill in the
art, such as heating or cracking the bitumen to produce synthetic
crude. The process of refining synthetic crude may also include any
processes known to those of ordinary skill in the art, such as
distillation, hydrocracking, hydrotreating and coking. They
petroleum products produced by the upgrading process are not
limited, any may include petroleum, diesel fuel, asphalt base,
heating oil, kerosene, and liquefied petroleum gas.
[0093] Referring back to FIG. 1, step 130 includes mixing the light
hydrocarbon distillate produced in the first nozzle reactor with a
further quantity of material comprising bitumen. The light
hydrocarbon distillate may act as a solvent capable of dissolving
bitumen, and therefore can be used in the first mixing step 100
described above. In certain embodiments, the light hydrocarbon
distillate can supplement or eliminate the first solvent used to
dissolve bitumen in the first step of the method of this embodiment
to thereby reduce or eliminate the need for obtaining first solvent
from a third party when carrying out a solvent extraction step on
the material comprising bitumen.
[0094] The manner in which the light hydrocarbon is mixed with a
further quantity of material comprising bitumen may be similar or
identical to any of the manners of mixing described above with
respect to step 100 and the mixing of the first solvent with the
first quantity of material comprising bitumen.
[0095] Although not depicted in FIG. 1, the method of this
embodiment may include further steps for processing the first
solvent-wet tailings to remove the first solvent from the tailings.
As noted above, the first solvent-wet tailings may include from
about 5 wt % to about 25 wt % of the first solvent Removing the
first solvent from the tailings may produce a more environmentally
friendly tailings product.
[0096] Accordingly, the method may further include a step of
separating the first solvent component of the first solvent-wet
tailings from the first solvent-wet tailings by adding a second
solvent to the first solvent-wet tailings. Removal of the first
solvent with a second solvent displaces the first solvent from the
first solvent-wet tailings. Some second solvent added to the first
solvent-wet tailings may remain therein, which results in the first
solvent-wet tailings becoming second solvent-wet tailings. The
second solvent component of the second solvent-wet tailings may be
also be removed to thereby produce solvent-free tailings.
[0097] The second solvent can be any suitable solvent that is
useful for displacing the first solvent. In certain embodiments the
second solvent has a lower vapor pressure than the first solvent to
enhance removal of the second solvent in subsequent processing
steps. In certain embodiments, the second solvent may be a
hydrocarbon solvent. Any suitable hydrocarbon solvent or mixture of
hydrocarbon solvents that is capable of displacing the first
solvent may be used. The hydrocarbon solvent or mixture of
hydrocarbon solvents can be economical and relatively easy to
handle and store. The hydrocarbon solvent or mixture of hydrocarbon
solvents may also be generally compatible with refinery
operations.
[0098] In certain embodiments, the second hydrocarbon solvent can
include one or more volatile hydrocarbon solvents. Volatile
hydrocarbon solvents generally include hydrocarbons having a
boiling point temperature between about -20.degree. C. and
150.degree. C. Volatile hydrocarbon solvents may also include
aliphatic compounds that are capable of solvating bitumen and/or
the first solvent. These aliphatic compounds can include compounds
such as branched or unbranched alkanes or alkenes. Any of these
aliphatic compounds can be functionalized or non-functionalized. In
certain embodiments, the second solvent includes one or more
aliphatic hydrocarbons having 3 to 9 carbon atoms. In some
embodiments, the second solvent includes aliphatic hydrocarbons
having no more than 9 carbon atoms. The second solvent may also
include lower carbon paraffins, such as cyclo- and iso-paraffins
having 3 to 9 carbon atoms. The second solvent may include one or
more of any of the following compounds: methane, ethane, propane,
butane, and/or pentane, alkene equivalents of these compounds
and/or combinations and derivatives thereof.
[0099] In certain embodiments, the second solvent includes
liquefied petroleum gas (LPG). The term "liquefied petroleum gas"
is used broadly herein to refer to any hydrocarbon gas
(hydrocarbons that are gases at ambient temperature (25.degree. C.)
and pressure (1 atm) and has been compressed to form a liquid.
Preferably, the LPG is primarily or even entirely propane or
predominantly or entirely butane. However, other LPG formulations
are contemplated including commercially available formulations. The
composition of common commercial LPG can vary depending on the time
of the year, geographical location, etc. Commercial LPG is a
natural derivative of both natural gas and crude oil. Often, LPG is
a mixture of propane and butane (n-butane and/or i-butane) with
small amounts of propylene and butylene (any one or combination of
the four isomers). A powerful odorant such as ethanethiol is
typically added to make it easy to detect leaks. Commercial LPG
also often contains very small amounts of lighter hydrocarbons,
such as ethane and ethylene, and heavier hydrocarbons such as
pentane.
[0100] Three examples of commercial LPG are shown below in Table
2.
TABLE-US-00003 TABLE 2 Examples of Commercially Available LPG
Commercial Commercial Butane/ Component HD-5 Propane Propane
Propane Mixture Lighter Min 90 v-% propane Mixture of propane
Mixture of butane Hydrocarbons Max v-5% propylene and/or propylene
and/or butylenes and propane and/or propylenes Butane and 2.5 v-%
2.5 v-% -- heavier hydrocarbons Pentane and -- -- Max v-2% heavier
hydrocarbons Residual matter 0.05 ml 0.05 ml -- Total Sulfur 123
w-PPM 185 w-PPM 140 w-PPM
[0101] LPG is stored and transported under pressure to maintain the
hydrocarbons as liquids. In certain embodiments, LPG has a boiling
point at atmospheric pressure of approximately -80.degree. C. to
10.degree. C., desirably, approximately -55.degree. C. to 5.degree.
C., or, suitably, approximately -35.degree. C. to -5.degree. C.
[0102] Adding second solvent to the first solvent-wet tailings may
be carried out in any suitable manner that results in first solvent
displacement from the first solvent-wet tailings. In certain
embodiments, second solvent may be added to the first solvent-wet
tailings in a similar or identical manner to the addition of first
solvent to the first solvent-wet tailings described in greater
detail above. In certain embodiments, the second solvent is added
to the first solvent-wet tailings without overly agitating the
first solvent-wet tailings in order to avoid the formation of
water-solvent emulsions as discussed in greater detail above.
[0103] The amount of the second solvent added to the first
solvent-wet tailings is sufficient to effectively displace at least
a portion, or desirably all, of the first solvent in the first
solvent-wet tailings. The amount of second solvent added to the
first solvent-wet tailings is approximately 0.5 to 1 times the
amount of bitumen by volume originally contained in the material
comprising bitumen.
[0104] In certain embodiments, the addition of second solvent to
the first solvent-wet tailings results in the removal of 95% or
more of the first solvent in the first solvent-wet tailings. The
first solvent may leave the first solvent-wet tailings as a first
solvent-second solvent mixture. The first solvent-second solvent
mixture may include from about 5 wt % to about 50 wt % first
solvent and from about 50 wt % to about 95 wt % second solvent. The
removal of the first solvent from the first solvent-wet tailings
through the addition of second solvent may result in a quantity of
second solvent not passing all the way through the first
solvent-wet tailings. Consequently, the first solvent-wet tailings
become a second solvent-wet tailings upon separation of the first
solvent. In certain embodiments, the second solvent-wet tailings
include from about 70 wt % to about 95 wt % non-bitumen components
and from about 5 wt % to about 30 wt % second solvent.
[0105] As with previously described separation steps, separation of
the first solvent from the first solvent-wet tailings by adding
second solvent may be preceded or followed by applying pressurized
gas over the first solvent-wet tailings. Applying a pressurized gas
over the first solvent-wet tailings facilitates the separation of
the first solvent component of the first solvent-wet tailings from
the non-bitumen components of the first solvent-wet tailings. The
liberated first solvent can then be displaced from the first
solvent-wet tailings by applying additional second solvent to the
first solvent-wet tailings. Applying a pressurized gas over the
first mixture may also provide a driving force for moving
bitumen-enriched solvent phase out of the first mixture without the
need for adding additional first solvent. Any suitable gas may be
used. In certain embodiments, the gas is nitrogen, carbon dioxide
or steam. The gas may also be added over the second mixture in any
suitable amount. In certain embodiments, 62.5 ft.sup.3 to 375
ft.sup.3 of gas per ton of material comprising bitumen is used.
This is equivalent to a range of about 4.5 liters to 27 liters of
gas per liter of material comprising bitumen. In some embodiments,
125 ft.sup.3 of gas per ton of material comprising bitumen is
used.
[0106] In certain embodiments, separation of the first solvent from
the first solvent-wet tailings utilizes a plate and frame-type
filter press. The plate and frame-type filter press may be a
separate plate and frame-type filter press from the plate and
frame-type filter press used to separate the bitumen-enriched
solvent phase from the first mixture and/or the first solvent-wet
tailings, or the same plate and frame-type filter press may be used
to separate the bitumen-enriched solvent phase from the first
mixture (or first solvent-wet tailings) and to separate the first
solvent from the first solvent-wet tailings. When the same plate
and frame-type filter press is used, the method may include adding
second solvent to the first solvent-wet tailings still contained in
the frame chamber. In other words, the method need not necessarily
always include a step of removing the first solvent-wet tailings
from the plate and frame-type filter press before mixing with
second solvent. The second solvent may be pumped into the plate and
frame-type filter press where it displaces the first solvent
component of the first solvent-wet tailings located in the frame
chambers.
[0107] When utilizing a plate and frame-type filter press to
separate the first solvent from the first solvent-wet tailings,
pressurized gas may be injected into the frame chamber after the
frame chamber has been filled with the first solvent-wet tailings.
In certain embodiments, injecting pressurized gas into the first
solvent-wet tailings can promote the separation of the first
solvent from mineral solids in the first solvent-wet tailings. The
process for adding gas can be similar or identical to the method
described above with respect to separation of the bitumen-enriched
solvent phase from the first mixture (or first solvent-wet
tailings) in a plate and frame-type filter press.
[0108] The second solvent passes through the first solvent-wet
tailings loaded in the frame chamber and displaces the first
solvent. In certain embodiments, 95% or more of the first solvent
in the first solvent-wet tailings is displaced by the second
solvent. This first solvent passes through the filter clothes and
out of the frame chamber. Some of the second solvent can also pass
through the filter clothes, while some second solvent can remain in
the frame chamber. Consequently, the first solvent-wet tailings
become second solvent-wet tailings.
[0109] The separation of first solvent from the first solvent-wet
tailings through the addition of second solvent may also be carried
out as a countercurrent washing process. The countercurrent process
generally includes moving the first solvent-wet tailings in one
direction while passing the second solvent through the first
solvent-wet tailings in an opposite direction. For example, the
first solvent-wet tailings may be loaded at the bottom of a screw
classifier conveyor positioned at an incline, while second solvent
is introduced at the top of the inclined screw classifier conveyor.
As the screw classifier conveyor moves the first solvent-wet
tailings upwardly, the second solvent flows down the inclined screw
classifier conveyor and passes through the first solvent-wet
tailings. The two materials mix and first solvent is displaced by
the second solvent, thereby "washing" the first solvent from the
first solvent-wet tailings. In certain embodiments, 85% or more of
the first solvent in the first solvent-wet tailings is displaced by
the second solvent. The first solvent-second solvent mixture that
collects at one end of the screw classifier conveyor may include
from about 5 wt % to about 50 wt % first solvent and from about 50
wt % to about 95 wt % second solvent. Some of the second solvent
may remain with the tailings, thereby forming the second
solvent-wet tailings that collect at the opposite end of the screw
classifier conveyor. In certain embodiments, the second solvent-wet
tailings includes from about 10 wt % to about 30 wt % second
solvent and from about 70 wt % to about 90 wt % non-bitumen
components.
[0110] The countercurrent process may include multiple stages as
described in greater detail above with respect to washing the first
mixture or first solvent-wet tailings. In a multiple stage
countercurrent process, the second solvent can displace
progressively more first solvent after each stage and the first
solvent-wet tailings lose progressively more first solvent after
each stage.
[0111] When separation of the bitumen-enriched solvent phase from
the first mixture is carried out using a vertical column as
described in greater detail above, the first solvent component
included in the first solvent-wet tailings loaded in the vertical
column may be separated, at least to some degree, from the first
solvent-wet tailings by injecting the second solvent at the top end
of the vertical column. In this manner, second solvent may flow
down through the vertical column and displace the first solvent
contained in the first solvent-wet tailings loaded in the vertical
column. A mixture of first solvent and second solvent may be
collected at the bottom end of the vertical column, while some
second solvent may remain in the vertical column, leading the first
solvent-wet tailings to become second solvent-wet tailings.
[0112] The second solvent may be injected into the vertical column
by any suitable method. In certain embodiments, the first quantity
of second solvent is poured into the vertical column at the top end
and allowed to flow down through the first mixture loaded therein.
The downward flow of the second solvent can be allowed to progress
under the force of gravity or external forces may be applied, such
as pressure at the top of the vertical column or suction at the
bottom of the vertical column.
[0113] The amount of second solvent added can vary. In some
embodiments, the amount is preferably enough second solvent to
displace most or all of the first solvent contained in the first
solvent-wet tailings loaded in the vertical column. In certain
embodiments, the first quantity of second solvent added to the
first mixture is from about 0.5 to about 2.0, and preferably about
1 times the amount of bitumen by volume contained in the original
material comprising bitumen. If multiple second solvent addition
steps are performed, then the total amount of second solvent added
is about 1.0 times the amount of bitumen by volume contained in the
original material comprising bitumen.
[0114] The mixture of first solvent and second solvent that flows
downwardly through the height of the column may exit the bottom end
of the vertical column where it may be collected for further use
and processing. In certain embodiments, the mixture of first
solvent and second solvent includes from about 50 wt % to about 90
wt % second solvent and from about 10 wt % to about 50 wt % first
solvent. Minor amounts of bitumen and non-bitumen material may also
be included in the mixture of first solvent and second solvent.
[0115] In certain embodiments, the addition of second solvent is
carried out under flooded conditions. In other words, more second
solvent is added to the top of the vertical column than what flows
down through the first mixture, thereby creating a head of solvent
at the top of the vertical column.
[0116] Various methods of collecting the mixture of first solvent
and second solvent may be used, such as by providing a collection
vessel at the bottom end of the vertical column. The bottom end of
the vertical column may include a metal filter screen having a mesh
size that does not permit the tailings to pass through but which
does allow for the mixture of first solvent and second solvent to
pass through and collect in a collection vessel located under the
screen. Collection of the mixture of first solvent and second
solvent may be carried out for any suitable period of time. In
certain embodiments, collection is carried out for 2 to 30
minutes.
[0117] Additional quantities of second solvent can be added to the
vertical column to increase the removal of first solvent. In other
words, after injecting a first quantity of second solvent and
collecting the mixture of first solvent and second solvent at the
bottom of the vertical column, additional quantities of second
solvent may be added to the vertical column to displace additional
first solvent from the tailings loaded in the vertical column. In
certain embodiments, the use of multiple second solvent injection
steps may result in removing 99% or more of the first solvent in
the first solvent-wet tailings.
[0118] Once the second solvent-wet tailings are obtained, the
second solvent component of the second solvent-wet tailings may be
removed from the second solvent-wet tailings to thereby produce a
more environmentally friendly tailings product. Various manners of
removing second solvent from the second solvent-wet tailings may be
used. In certain embodiments, the second solvent can be removed
from the second solvent-wet tailings by flashing or heating the
second solvent-wet tailings. In this manner, second solvent
evaporates from the second solvent-wet tailings and leaves behind
solvent-dry, stackable tailings. In some embodiments, pre-heated
gas, such as nitrogen, may be injected into the second solvent-wet
tailings to remove the second solvent. The pre-heated gas may be at
a temperature above the boiling point temperature of the second
solvent. Separation of the second solvent from the second
solvent-wet tailings may result in 95% or more of the second
solvent in the second solvent-wet tailings being removed.
[0119] When the second solvent is a volatile hydrocarbon, the
energy required to remove the second solvent may be minimal. In
certain embodiments, the second solvent may be removed from the
second solvent-wet tailings at room temperature. Separation of the
second solvent at room temperature or any temperature under the
boiling point temperature of water is also useful for avoiding the
removal of water from the tailings.
[0120] Separating second solvent from the second solvent-wet
tailings may also include separation of any first solvent included
in the second solvent-wet tailings. Separation of the first solvent
may occur together with the separation of the second solvent, such
as by heating or flashing the second-solvent wet tailings in a
manner causing both solvents to evaporate from the second-solvent
wet tailings. Alternatively, the separation may be incremental,
wherein the flashing or heating is carried out to start with at
conditions that will cause only the second solvent to evaporate,
followed by adjusting the conditions to cause the evaporation of
the first solvents. The first and second solvents separated from
the second solvent-wet tailings may be recovered and recycled
within the method.
[0121] The solvent-dry, stackable tailings resulting from removal
of the second solvent from the second solvent-wet tailings may
generally include inorganic solids, such as sand and clay, water,
and little to no first and second solvent. As used herein, the term
"solvent-dry" means containing less than 0.1 wt % total solvent. As
used herein, the term "stackable" means having a water content of
from about 2 wt % to about 15 wt %. This range of water content
creates a damp tailings that will not produce significant amounts
of dust when transporting or depositing the tailings. This range of
water content may also provide stackable tailings that will not
flow like dry sand, and therefore have the ability to be retained
within an area without the need for retaining structures (e.g., a
tailings pond). This range of water content also provides tailings
that are not so wet as to be sludge-like or liquid-like. The
solvent-dry, stackable tailings produced by the above described
method may also include less than 2 wt % bitumen and
asphaltene.
[0122] In another variation of the above described method, the
bitumen-enriched solvent phase may be separated into a bitumen
component and a first solvent phase prior to cracking the bitumen
component inside the first nozzle reactor to produce light
hydrocarbon distillate. In certain embodiments, 90% or more of the
first solvent in the bitumen-enriched first solvent phase may be
separated from the bitumen-enriched solvent phase to produce a
bitumen component.
[0123] Separation of the bitumen and the first solvent may be by
any suitable separation method that is capable of separating the
first solvent from the bitumen component. In certain embodiments,
separation may be achieved by heating the bitumen-enriched solvent
phase and separating first solvent from bitumen based on the
boiling point temperature of the first solvent. The heat can be
provided by any suitable heating source, such as by a heat
exchanger. Heating can be done substantially at ambient pressure,
at a pressure less than ambient, or at a pressure greater than
ambient. In certain embodiments, the separation of the first
solvent and the bitumen is accomplished by a distillation
tower.
[0124] Table 3 shows the boiling points of some of the components
that may be used as or included in the first solvent. In certain
embodiments, the bitumen-enriched solvent phase may be heated to a
temperature of approximately 70.degree. C. to 350.degree. C., such
as approximately 100.degree. C. to 350.degree. C., approximately
125.degree. C. to 250.degree. C., or, desirably, approximately
140.degree. C. to 220.degree. C.
TABLE-US-00004 TABLE 3 Solvent Boiling Points Boiling Compound
Point .degree. C. Fatty Acid Methyl Esters C8 187 C10 224 C12 262
C14 295 C16 338 C18 352 Aromatic Hydrocarbons Toluene 111 Xylene
140 Coal Tar Naphtha 150-220 Petroleum Naphtha 172-215 Light
distillate 140-260 Middle distillate 200-400 Aromatic/Solvesso 100
160-170 Aromatic/Solvesso 150 185-205 Aromatic/Solvesso 200
240-275
[0125] In some embodiments, separation may be accomplished by
utilizing a multi-hearth solvent recovery furnace. Multi-hearth
solvent recovery furnaces typically include alternating
arrangements of centrally located hearths and peripherally located
hearths. The hearths can be heated, for example, with oil fired
muffles and/or high pressure steam coils. In some embodiments,
hearths near the top of the furnace may be heated to higher
temperatures than hearths closer to the bottom of the furnace.
[0126] In certain embodiments, the bitumen-enriched solvent phase
may be routed to a separator to recover the first solvent. The
separator may separate the first solvent from bitumen product. The
separator may also be configured to separate any water and mineral
solids that might be present in bitumen-enriched solvent phase.
Separation of the bitumen-enriched solvent phase may also be
configured to function despite the presence of fine solid material.
For example, a separator used to separate the first solvent from
the bitumen can include a suitable packing material, such as
vertical slats, to provide increased surface area for condensation
and evaporation. This packing material can be resistant to clogging
by the fine solid material. In those embodiments where the
separation is accomplished by utilizing a distillation tower, the
fine solid materials may fall to the bottom and be cleaned out
periodically.
[0127] Just as with previous separation and mixing steps,
separation of first solvent from bitumen can be performed as a
continuous, batch, or semi-batch process. Continuous processing is
typically used in larger scale implementations. However, batch
processing may result in more complete separations than continuous
processing.
[0128] Once the first solvent is separated from the bitumen, the
first solvent may be recycled for further use in the same process
or collected for use in other processes. When recycled for use in
the same process, the first solvent may be transported back to, for
example, a first vessel used to mix the material comprising bitumen
and the first solvent. The recycled first solvent may be used to
supplement or replace a fresh source of first solvent used in the
first mixing step. The recycled first solvent may also be used with
the light hydrocarbon liquid distillate to eliminate the need for
fresh first solvent in the first solvent extraction stage. In other
words, rather than using first solvent obtained from a third party
to carry out the first solvent extraction stage, the light
hydrocarbon liquid distillate may supplement the recycled first
solvent to whatever extent necessary in order to provide a
sufficient amount of first solvent for solvent extracting bitumen
from additional quantities of material comprising bitumen.
[0129] In some embodiments, the method may include extracting
bitumen from a bitumen comprising material, deasphalting the
extracted bitumen to produce asphaltenes, cracking the asphaltenes
inside a nozzle reactor to form light hydrocarbon distillate, and
using the light hydrocarbon distillate to extract bitumen from
further material comprising bitumen.
[0130] As shown in FIG. 3, the method can generally include a first
step 300 of mixing a first quantity of material comprising bitumen
with a first solvent to form a first mixture, a step 310 of
separating the first mixture into a bitumen-enriched solvent phase
and a first solvent-wet tailings, a step 320 of separating the
bitumen-enriched solvent phase into a first bitumen component and a
first solvent stream, a step 330 of deasphalting the first bitumen
component to form an asphaltene stream and a first hydrocarbon
stream, a step 340 of cracking the asphaltene stream inside a first
nozzle reactor to form a light hydrocarbon distillate and a
non-participating hydrocarbon stream, and a step 350 of mixing the
light hydrocarbon distillate with a second quantity of material
comprising bitumen.
[0131] First steps 300 and 310 may be essentially identical to
steps 100 and 110 described in greater detail above. A first
solvent as described above may be mixed with a material comprising
bitumen as described above to dissolve the bitumen in the material
comprising bitumen. A first mixture formed by mixing the first
solvent and the material comprising bitumen may be separated into a
bitumen-enriched solvent phase as described above and a first
solvent-wet tailings as described above. Steps 300 and 310 may be
repeated one or more times to extract additional bitumen from the
first solvent-wet tailings.
[0132] In step 320, the bitumen-enriched solvent phase can be
separated into a bitumen component and a first solvent stream.
Various manners of separating the first solvent from the bitumen
may be used. In certain embodiments, 90% or more of the first
solvent in the bitumen-enriched first solvent phase may be
separated from the bitumen-enriched solvent phase to produce a
bitumen component.
[0133] Separation of the bitumen and the first solvent may be by
any suitable separation method that is capable of separating the
first solvent from the bitumen component. In certain embodiments,
separation may be achieved by heating the bitumen-enriched solvent
phase and separating first solvent from bitumen based on the
boiling point temperature of the first solvent. The heat can be
provided by any suitable heating source, such as by a heat
exchanger. Heating can be done substantially at ambient pressure,
at a pressure less than ambient, or at a pressure greater than
ambient. In certain embodiments, the separation of the first
solvent and the bitumen may be accomplished by a distillation
tower.
[0134] In some embodiments, separation may be accomplished by
utilizing a multi-hearth solvent recovery furnace. Multi-hearth
solvent recovery furnaces typically include alternating
arrangements of centrally located hearths and peripherally located
hearths. The hearths can be heated, for example, with oil fired
muffles and/or high pressure steam coils. In some embodiments,
hearths near the top of the furnace are heated to higher
temperatures than hearths closer to the bottom of the furnace.
[0135] In certain embodiments, the bitumen-enriched solvent phase
may be routed to a separator to recover the first solvent. The
separator may separate the first solvent from bitumen product. The
separator may also be configured to separate any water and mineral
solids that might be present in bitumen-enriched solvent phase.
Separation of the bitumen-enriched solvent phase may also be
configured to function despite the presence of fine solid material.
For example, a separator used to separate the first solvent from
the bitumen can include a suitable packing material, such as
vertical slats, to provide increased surface area for condensation
and evaporation. This packing material can be resistant to clogging
by the fine solid material. In those embodiments where the
separation is accomplished by utilizing a distillation tower, the
fine solid materials may fall to the bottom and be cleaned out
periodically.
[0136] The cut temperature of the separator may affect the amount
of new first solvent present in the separated first solvent. For
example, at a cut temperature of 225.degree. C., an additional 4.8
vol % of first solvent may be present in the separated first
solvent as new solvent. This additional first solvent may be
blended back with the bitumen product produced by the separator in
order to lower the viscosity and make the bitumen product more
pipelineable.
[0137] As described above, first solvent removed from the
bitumen-enriched solvent phase may be recycled for further use in
the same process or collected for use in other processes. When
recycled for use in the same process, the first solvent may be
transported back to, for example, a first vessel used to mix the
material comprising bitumen and the first solvent. The recovered
first solvent may be used to supplement or eliminate a fresh feed
of first solvent. The recovered first solvent may also be used to
supplement first light hydrocarbon distillate produced in the
nozzle reactor and recycled back to the first solvent extraction
step.
[0138] In step 330, the bitumen obtained from separating the
bitumen-enriched first solvent phase as described above can be
deasphalted to produce an asphaltene stream. Deasphalting may be
accomplished by any suitable manner for deasphalting bitumen.
Examples of suitable deasphalting processes include, but are not
limited to, the Residuum Oil Supercritical Extraction (ROSE.TM.)
process, ambient pressure solvent deasphalting (SDA), and propane
deasphalting (PDA).
[0139] The type and amount of asphaltene produced by the
deasphalting step may depend on both the solvent used to perform
the deasphalting process and the source of the bitumen material be
deasphalted. Bitumen generally includes multiple types of
asphaltene. Each type of asphaltene may be classified by the alkane
solvent in which the asphaltene is insoluble. For example, a
bitumen sample may include a propane-insoluble asphaltene fraction,
a butane-insoluble asphaltene fraction, a pentane-insoluble
asphaltene fraction, and so on. Table 4 below presents the
asphaltene content of Athabasca bitumen based on various alkane
solvents used to precipitate the asphaltene.
TABLE-US-00005 TABLE 4 Asphaltene Precipitated Solvent from
Athabasca Bitumen (wt %) Propane 48 Butane 28 Pentane 18 Hexane 14
Heptane 11 Octane 9.8 Nonane 9.4 Decane 9.0
[0140] However, it should be noted that while Table 4 indicates
that the pentane-insoluble asphaltene content of Athabasca bitumen
is 18 wt %, the amount of pentane-insoluble asphaltene content of
bitumen may range from about 10 wt % to about 50 wt % of the
bitumen based on the source of bitumen. Once a solvent has been
selected for precipitating a particular asphaltene fraction, the
deasphalting step may generally recover from about 25% to 100% of
the content of that asphaltene fraction in the bitumen
component.
[0141] Deasphalting may produce an asphaltene product and a
hydrocarbon product that includes primarily the remaining
hydrocarbon fractions of the bitumen. The remaining hydrocarbons
may generally include hydrocarbons having a molecular weight less
than about 300 Daltons. The hydrocarbons may also be essentially
asphaltene-free In many cases, certain fractions of the remaining
hydrocarbons may be processed further by refinery processing to
produce various commercial products, such as gasoline, naptha,
kerosene and diesel oil.
[0142] In step 330, the asphaltene stream produced from the
deasphalting step 320 may be used to form a light hydrocarbon
liquid distillate by cracking the asphaltene stream inside a nozzle
reactor. In this regard, step 330 may be similar or identical to
step 120 described in greater detail above. The nozzle reactor may
be similar or identical to the nozzle reactor described above. A
cracking material may be injected into an interior reactor chamber
while simultaneously injecting the asphaltene stream into the
interior reactor chamber via the material feed passage. The
asphaltene stream may enter the interior reactor chamber at a
direction transverse to the direction the cracking material is
injected into the interior reactor chamber. Shock waves produced by
the cracking material may result in the cracking of the asphaltene
material into light hydrocarbon liquid distillate having a
molecular weight less than 300 Daltons. Asphaltene material not
cracked inside the nozzle reactor may be considered
non-participating hydrocarbon material and may be routed to a
second nozzle reactor for further cracking.
[0143] In certain embodiments, the aspahltene stream injected into
the first nozzle reactor may not be pure asphaltene. Rather, the
asphaltene stream may also include resins and other heavy
hydrocarbons. When such an asphaltene stream is injected into the
nozzle reactor under certain operating conditions, the asphaltenes
may be in a liquid phase while the resins and other heavy
hydrocarbons may be in a gaseous state. Accordingly, the resins and
hydrocarbons may pass through the nozzle reactor uncracked, while
the shock waves produced inside the nozzle reactor will crack the
asphaltenes into the light hydrocarbon liquid distillate. If shock
waves miss some of the asphaltenes injected into the nozzle reactor
or only partially crack some of the asphaltenes injected into the
nozzle reactor during the short time that the asphaltenes are
inside the nozzle reactor, then these asphaltenes may also pass
through the nozzle reactor uncracked or not fully cracked and
become part of the non-participating hydrocarbon stream.
[0144] A typical composition of the light hydrocarbon liquid
distillate produced by step 340 is summarized in Table 5.
TABLE-US-00006 TABLE 5 Characteristics of Light Hydrocarbon Liquid
Distillate Initial Boiling Point 140.degree. C.-160.degree. C. API
Gravity 22-30 Kinematic Viscosity 5-7 cSt (at 140.degree. F.)
Typical Carbon Content 83-84 wt % Typical Hydrogen Content 11-12 wt
% Typical Sulfur Content 1.5 wt % Micro Carbon Residue ~1 wt %
Bromine Number 19 Olefin Content 20-24 wt % Sara Analysis - Pentane
Solvent Saturates 35 wt % Aromatics 50-60 wt % Resins 10-15 wt %
Asphaltenes <1 wt %
[0145] Two exemplary components of the light hydrocarbon liquid
distillate include naphtha and kerosene. Both naphtha and kerosene
include aromatics and naphthenes for dissolving bitumen, making the
light hydrocarbon liquid distillates suitable for use as first
solvents. The table below summarizes key characteristics of the
exemplary components of the light hydrocarbon liquid distillate.
Because both naphtha and kerosene include about 60 wt % solvating
components, naphtha and kerosene have about equal solvating
(bitumen dissolution) power.
TABLE-US-00007 TABLE 5a Solvating Component Content of Light
Hydrocarbon Liquid Distillates Naphtha Kerosene Boiling Point Range
(.degree. C.) 145-190 190-260 Typical Yield from Bitumen 4 wt % 10
wt % Cracking in Nozzle Reactor Content of Solvating Components for
Bitumen Dissolution Aromatics 27 wt % 34 wt % Naphthenes 33 wt % 30
wt %
[0146] In step 350, the light hydrocarbon liquid distillate
produced during step 340 may be mixed with a second quantity of
material comprising bitumen. In this regard, step 350 is similar or
identical to step 130 described in greater detail above. The light
hydrocarbon liquid distillate may act as a suitable solvent for
dissolving the bitumen content of the material comprising bitumen.
As such, the light hydrocarbon distillate may be used in the first
mixing step 300 described above. In certain embodiments, the light
hydrocarbon liquid distillate may supplement or replace the first
solvent used in the first mixing step.
[0147] As with the previous embodiments, the method may include
additional steps for processing the first solvent-wet tailing phase
separated from the bitumen-enriched solvent phase in step 310.
Processing of the first solvent-wet tailings may include a step of
mixing the first solvent-wet tailings with a second solvent to form
a second mixture, separating the second mixture into a first
solvent-enriched second solvent phase and a second solvent-wet
tailings, and separating the second solvent from the second
solvent-wet tailings. These steps may be similar or identical to
the steps described above, including the use of a volatile
hydrocarbon solvent as the second solvent, the option of using a
plate and frame filter press for the separation step, the option of
using a countercurrent washing process to perform the mixing and
separation steps, and the use of a flashing unit or pre-heated gas
to separate second solvent from the second solvent-wet
tailings.
[0148] In some embodiments, a system for obtaining light
hydrocarbon liquid distillate from material comprising bitumen
includes mixers, separators and nozzle reactors. The system may
include a first mixer for mixing a material comprising bitumen and
a first solvent to form a first mixture, a first separator for
separating the bitumen-enriched solvent from the first mixture, a
nozzle reactor for cracking the bitumen component of the bitumen
enriched solvent phase into a light hydrocarbon liquid distillate,
and a recycle stream for recycling the light hydrocarbon distillate
back to the first mixer.
[0149] FIG. 4 is a schematic diagram illustrating a system for
obtaining light hydrocarbon distillate from material comprising
bitumen. A material comprising bitumen 400 and a first solvent 410
may be routed to a first mixer 420. The material comprising bitumen
400 and first solvent 410 may be mixed in first mixer 420 as
described above in connection with step 100. For example, the
material comprising bitumen 400 and the first solvent 410 may be
mixed by the agitation caused by introducing the components into
the first mixer 420 or by a powered mixing device.
[0150] The material comprising bitumen 400 and the first solvent
410 may be as described above in the method of the previous
embodiment. In one specific example, the material comprising
bitumen 400 may be tar sands and the first solvent 410 may be a
light aromatic solvent. The material comprising bitumen 400 and the
first solvent may be mixed according to the ratios set forth above
in the description of step 100.
[0151] Once mixed together, the material comprising bitumen 400 and
the first solvent 410 form a first mixture 430. The first mixture
may be routed to a first separator 440, such as by pumping the
first mixture 430 through piping fluidly connecting the first mixer
420 and the first separator. In an alternate embodiment, the first
mixer 420 and the first separator 440 may be the same vessel.
[0152] The first separator 440 separates bitumen-enriched solvent
phase 450 from the first mixture 430. Removal of the
bitumen-enriched solvent phase 450 results in the first mixture 430
becoming first solvent-wet tailings 460, which may be discharged
from the first separator 440. The first separator 440 may be any
type of separator suitable for separating the bitumen-enriched
solvent phase 450 from the first mixture 430. As discussed above in
greater detail, the bitumen-enriched solvent phase 450 may be
separated from the first mixture 430 by, for example, settling,
filtering or by performing gravity drainage on the first mixture
430. Accordingly, first separator 440 may be, for example, a
settling vessel, a filtration vessel or a gravity drainage vessel.
As also discussed above, first separator 440 may perform a two
stage separation, with the second stage involving the addition of
further first solvent to the first mixture 430 to displace residual
bitumen-enriched solvent phase remaining in the first mixture 430
after the first stage of separation.
[0153] The bitumen-enriched solvent phase 450 is routed to a nozzle
reactor 470, such as by pumping the bitumen-enriched solvent phase
450 through piping fluidly connecting the first separator 440 and
the nozzle reactor 470. The bitumen-enriched solvent phase 450 is
injected into the nozzle reactor 470 and at least a portion of the
bitumen component of the bitumen-enriched solvent phase 450 is
cracked into lighter hydrocarbon material.
[0154] As discussed in greater detail above, the nozzle reactor 470
can be any nozzle reactor wherein differing types of materials are
injected into an interior reactor chamber of the nozzle reactor 470
and caused to interact within the interior reactor chamber in order
to alter the mechanical or chemical composition of one or more of
the materials. In certain embodiments, the nozzle reactor 470 may
be a nozzle reactor as described in co-pending U.S. application
Ser. No. 11/233,385. In such a nozzle reactor, a cracking material
475 is injected into the interior reaction chamber of the nozzle
reactor 470 at an accelerated and possibly supersonic speed, while
the bitumen-enriched solvent phase 450 is injected into the
interior reaction chamber of the nozzle reactor 470 at a direction
transverse to the direction that the cracking material 475 is
injected into the nozzle reactor 470.
[0155] The interaction between the bitumen component and the
cracking material 475 cracks at least a portion of the bitumen
component. A portion of the bitumen component that is cracked is
cracked into a light hydrocarbon liquid distillate 480 having a
molecular weight less than 300 Daltons. Other components of the
bitumen-enriched solvent phase 450 may be cracked, but not to the
molecular weight range for light hydrocarbon distillate 480. Still
other components of the bitumen-enriched solvent phase 450 may not
be cracked inside the nozzle reactor 470 and will exit the nozzle
reactor 470 in the same condition as when it entered the nozzle
reactor 470. The uncracked material and the material cracked to a
molecular weight outside of the range for light hydrocarbon
distillate 480 are considered non-participating hydrocarbon.
Accordingly, the nozzle reactor 470 may produce a light hydrocarbon
distillate stream 480 and a combined non-participating hydrocarbon
stream 490.
[0156] The combined non-participating hydrocarbon stream 490 may
include hydrocarbon material that is suitable for use as a
commercial product or that requires further processing to upgrade
the hydrocarbon material into a useful commercial product.
Accordingly, combined non-participating hydrocarbon stream 490 may
be collected for consumption and/or subjected to further processing
to upgrade the hydrocarbon material into useful products. In
certain embodiments, the combined non-participating hydrocarbon
stream 490 may be injected into a second nozzle reactor for further
attempts at cracking the non-participating hydrocarbons.
[0157] The light hydrocarbon distillate 480 may be recycled within
the system for use in mixer 420. That is to say, the light
hydrocarbon distillate 480 may be mixed with material comprising
bitumen 400 in mixer 420 to begin the process of extracting bitumen
from the material comprising bitumen 400. The light hydrocarbon
distillate 480 may supplement first solvent 410 to provide a
sufficient amount of solvent to mix with the material comprising
bitumen 400 in the mixer 420, or may replace the first solvent 410
such that only light hydrocarbon distillate 480 is mixed with
material comprising bitumen 400 in first mixer 420. A light
hydrocarbon distillate bleed stream 485 may also be included in the
system such that the light hydrocarbon distillate is not constantly
recycled within the system.
[0158] In addition to the light hydrocarbon distillate 480 and
combined non-participating hydrocarbon stream 490, the nozzle
reactor 470 may also emit cracking material that has not
participated in a chemical reaction with the bitumen-enriched
solvent phase 450. The nozzle reactor 470 may also emit a small
amount of gaseous product produced inside the nozzle reactor, such
as hydrogen and methane.
[0159] FIG. 5 shows how the system illustrated in FIG. 4 may also
include equipment for processing the first solvent-wet tailings
460. First solvent-wet tailings 460 may be transported to a second
separator 500, such as by pumping the first solvent-wet tailings
460 through piping fluidly connecting the first separator 440 with
the second separator 500. A second solvent 510 may be added to the
first solvent wet tailings 460 in the second separator 500, which
results in the displacement of first solvent out of the first
solvent-wet tailings 460. Second solvent 510 may be added to the
first solvent-wet tailings 460 in any amount described above and
according to any to procedure described above. For example, the
second solvent 510 may be added to the first solvent-wet tailings
460 in a countercurrent washing process.
[0160] The first solvent leaves the second separator 500 as a first
solvent-second solvent mixture 520. The addition of second solvent
510 to the first solvent-wet tailings 460 results in the first
solvent-wet tailings 460 becoming second solvent-wet tailings 530
due to some of the second solvent 510 remaining in the
tailings.
[0161] The first solvent-second solvent mixture 520 may be sent to
a third separator 540, such as by pumping the first solvent-second
solvent mixture 520 through piping fluidly connecting the second
separator 500 and the third separation unit 540. The first
solvent-second solvent mixture 520 is separated into first solvent
550 and second solvent 560. The third separator 540 may be any type
of separator suitable for separating first solvent 550 and second
solvent 560, such as a still. The first solvent 550 may then be
recycled back in the system for use in the first mixer 420. The
first solvent 550 may supplement or eliminate the first solvent 410
used to carry out the solvent extraction of bitumen in mixer 420.
In certain embodiments, the first solvent 550 may be used with the
light hydrocarbon distillate 480 to eliminate the need for first
solvent 410. Similarly, the second solvent 560 may be recycled back
in the system for use in the second separator 500. The second
solvent 560 may be used to supplement or eliminate the second
solvent 510.
[0162] The second solvent-wet tailings 530 are transported to a
fourth separator 570, such as by pumping the second solvent-wet
tailings 530 through piping fluidly connecting second separator 500
and the fourth separator unit 570. The fourth separator 570
separates the second solvent from the second solvent-wet tailings
530. Fourth separator 570 may be any suitable type of separator for
separating second solvent from the second solvent-wet tailings 530,
such as a heating or flashing unit. Second solvent stream 580
produced by fourth separator 570 may be recycled back to second
separator 500 for use with, or in place of, second solvent 510.
Fourth separator 570 also produces a tails stream 590 that contains
little or no second solvent.
[0163] FIG. 6 is a schematic diagram illustrating a system similar
to the system illustrated in FIG. 4, but including further
processing equipment for conducting deasphalting on bitumen
material. As with FIG. 4, the system includes a first mixer 610 for
mixing material comprising bitumen 600 with first solvent 605 and a
first separator 620 for separating a bitumen-enriched solvent phase
625 from a first mixture 615 and producing first solvent-wet
tailings 630 by the removal of the bitumen-enriched solvent phase
625 from the first mixture 615.
[0164] In the case of the system illustrated in FIG. 6, the
bitumen-enriched solvent phase 625 undergoes further processing
prior to being injected into a nozzle reactor 670. Firstly, the
bitumen-enriched solvent phase 625 is transported to second
separator 635 for separating the bitumen-enriched solvent phase 625
into bitumen component 640 and first solvent 645. The second
separator 635 may be any suitable separator for separating first
solvent 645 from the bitumen component 640, such as a heater that
evaporates the first solvent 645 from the bitumen-enriched solvent
phase 625. The first solvent 645 may be recycled back within the
system to the first mixer 610, where it may supplement or eliminate
the first solvent 605.
[0165] The bitumen component 640 obtained from the second
separation unit 635 is transported to a deasphalter 650. The
deasphalter 650 may perform any suitable type of deasphalting step
on the bitumen component 640, such as the ROSE.TM. process or
propane solvent deasphalting process discussed previously.
Deasphalting unit 650 produces an asphaltene stream 655 and a
hydrocarbon stream 660. The hydrocarbon stream 660 may be collected
to undergo further processing for the purpose of producing
commercially useful product. The asphaltene stream 655 is injected
into the nozzle reactor 670.
[0166] From this point on, the system shown in FIG. 6 is again
similar to the system shown in FIG. 4. Cracking material 665 is
injected into the nozzle reactor 670 at supersonic speeds to create
shockwaves that crack portions of the asphaltene stream 655
injected into the nozzle reactor 670. Some of the asphaltene stream
655 will be cracked to produce light hydrocarbon distillate 680,
while the remainder of the asphaltene stream 655 will become the
non-participating hydrocarbon stream 675. Like hydrocarbon stream
660, the non-participating hydrocarbon stream 675 may undergo
further processing (such as being passed through a second nozzle
reactor) to create commercially useful products. Light hydrocarbon
distillate 680 may be recycled within the system to be used in the
first solvent extraction of bitumen from material comprising
bitumen 600. The light hydrocarbon distillate may be used to
supplement the first solvent 605 and/or first solvent 645, or may
be used eliminate the need for first solvent 605 and first solvent
645. A light hydrocarbon distillate bleed stream 685 may also be
included in the system such that the light hydrocarbon distillate
is not constantly recycled within the system.
[0167] FIG. 7 shows how the system illustrated in FIG. 6 may also
include equipment for processing the first solvent-wet tailings
630. First solvent-wet tailings 630 may be transported to a third
separator 700, such as by pumping the first solvent-wet tailings
630 through piping fluidly connecting the first separator 620 with
the third separator 700. A second solvent 705 is added to the first
solvent-wet tailings 630 loaded in the third separator 700 to
displace first solvent from the first solvent-wet tailings 630. The
second solvent 705 may be any of the second solvents described
previously and mixing may be carried out as described in greater
detail above. The third separator 700 may be any type of separator,
such as a plate and frame-type filter press.
[0168] The first solvent-second solvent mixture 710 is transported
to a fourth separator 715, such as by pumping the first
solvent-second solvent mixture 710 through piping fluidly
connecting the third separator 700 and the fourth separator 715.
The first solvent-second solvent mixture 710 is separated into
first solvent 720 and second solvent 725. The fourth separator 715
may be any type of separation unit suitable for separating first
solvent 720 and second solvent 725, such as a still. The first
solvent 720 may then be recycled back in the system for use in the
first mixer 610. The first solvent 720 may supplement the first
solvent 605, first solvent 645 and/or the light hydrocarbon
distillate 680 used to carry out the solvent extraction of bitumen
in mixer 610. Similarly, the second solvent 725 may be recycled
back in the system for use in the second separator 700. The second
solvent 725 may be used to supplement or eliminate the second
solvent 705.
[0169] The second solvent-wet tailings 730 are transported to a
fifth separator 735, such as by pumping the second solvent-wet
tailings 730 through piping fluidly connecting third separator 700
and the fifth separator 735. The fifth separator 735 separates the
second solvent from the second solvent-wet tailings 730. Fifth
separator 735 may be any suitable type of separator for separating
second solvent from the second solvent-wet tailings 730, such as a
heating or flashing unit. Second solvent stream 745 produced by
fifth separator 735 may be recycled back to third separator 700 for
use with, or in place of, second solvent 705 and/or second solvent
725. Fifth separator 735 also produces a tails stream 740 that
contains little or no second solvent.
[0170] FIG. 8 is a schematic diagram illustrating a system that
falls between the systems shown in FIGS. 4 and 6. More
specifically, the system includes a separator 635 for separating
the bitumen-enriched solvent phase 625 into bitumen component 640
and first solvent 645, but does not include a deasphalter. As such,
the bitumen component 640 is injected into the nozzle reactor 670
without first undergoing a deasphlating step. FIG. 9 shows the
system of FIG. 8 together with additional units for processing the
first solvent-wet tailings 630.
[0171] In view of the many possible embodiments to which the
principles of the disclosed invention may be applied, it should be
recognized that the illustrated embodiments are only preferred
examples of the invention and should not be taken as limiting the
scope of the invention. Rather, the scope of the invention is
defined by the following claims. We therefore claim as our
invention all that comes within the scope and spirit of these
claims.
EXAMPLES
[0172] The following examples are provided to further illustrate
the subject matter disclosed herein. These examples should not be
considered as being limiting in any way.
[0173] In the following examples, bitumen was extracted from three
different tar sands--Trinidad tar sands ("Trinidad"), high grade
Athabasca tar sands ("AthHG"), and low grade Athabasca tar sands
("AthLG"). The composition of each tar sand material is shown in
Table 6 along with a brief description. The composition of each tar
sands was determined using a Dean-Stark apparatus. Before being
used in the examples, the tar sands were broken by hand into pieces
small enough to fit through a 0.5 inch diameter hole.
[0174] The bitumen was extracted from the tar sands using a
multi-stage extraction process that included two solvent extraction
steps. The tar sands were initially mixed with a liquid solvent
(the particular solvent is specified in the examples) at
atmospheric pressure. The mixture was separated into a
bitumen-enriched first solvent phase and first solvent-wet
tailings.
[0175] The first solvent-wet tailings were combined with LPG in a
pipe. The pressure in the pipe was sufficient to keep the LPG in a
liquid form. This combination was separated into a first
solvent-enriched second solvent phase and second solvent-wet
tailings.
[0176] The bitumen-enriched first solvent phase was injected into a
nozzle reactor. Steam was also injected into the nozzle reactor in
order to crack at least a portion of the bitumen in the
bitumen-enriched first solvent phase. The nozzle reactor produced
light distillate and a non-participating hydrocarbon stream.
TABLE-US-00008 TABLE 6 Tar sands Bitumen Water Sample (wt %) (wt %)
Description Trinidad 12 4.6 A blend of drill core samples obtained
from a tar sands in Trinidad. AthHG 12 4 A high grade tar sand
sample from the Athabasca Tar sands in Alberta, Canada. AthLG 8 5.5
A low grade tar sand sample from the Athabasca Tar sands in
Alberta, Canada.
Example 1
Trinidad Tar Sands
[0177] In this example, bitumen was extracted from a total of
eleven samples of a Trinidad tar sand project. The samples are
designated T-1 through T-11 in Table 7. The details of the
extraction of each sample can be found in Table 7 along with some
observations taken during each process.
[0178] Except as noted otherwise, each sample was processed using
the following procedure. Each sample was initially weighed and the
sample was placed into a mixing container along with the necessary
amount of the first solvent to achieve the proper solvent to
bitumen ratio specified in Table 7. The first solvent and the tar
sands were mixed with a standard three blade impeller. The tar
sands were leached for one hour in the mixing container. The
mixture was then filtered with a Buchner funnel with filter paper,
either with gravity or under vacuum or under atmospheric pressure,
to separate the liquids from the solids. The filtrate of liquids
formed a bitumen-enriched solvent phase and the filter cake of
solids formed first solvent-wet tailings.
[0179] The first solvent-wet filtrate was weighed and measured. The
first solvent-wet filter cake was subjected to addition of a second
solvent to remove any remnants of the first solvent in the filter
cake. The amount of the first solvent still present in the first
solvent-wet filter cake varied depending on the filtration time and
the particular solvent used.
[0180] The addition of the second solvent was performed by placing
the first solvent-wet filter cake into a pipe extractor and
introducing liquid LPG into the pipe extractor (commercial LPG was
used). The liquid LPG displaced any remaining amounts of the first
solvent from the first solvent-wet filter cake. The first
solvent-wet filter cake was soaked in the liquid LPG for fifteen
minutes. The liquids and solids in the mixture were separated into
a first solvent-second solvent mixture and second-solvent wet
tailings, respectively. The first solvent-second solvent mixture
included liquid LPG, bitumen, and first solvent. The LPG was
removed from the bitumen and first solvent by allowing it to
vaporize within the system. The bitumen and the first solvent (both
in the form of a liquid) were then captured in a flask. The weight
and amount of the liquids were measured. The remaining solids in
the pipe were also removed and weighed.
[0181] Some of the samples were extracted using the same procedure
described above with some subtle differences. Sample T-3 was mixed
with the first solvent in the mixing pipe followed directly by the
LPG soaking. Samples T-6 and T-7 were the same except that the
filter cake from T-6 was completely dry when placed in the pipe
extractor and the filter cake from T-7 was still wet when placed in
the pipe. Sample T-9 was extracted using a three step process that
included initially extracting bitumen with liquid LPG in the pipe,
separating the liquids and the solids, leaching the solids with the
first solvent in the mixing container, separating the liquids and
the solids, and extracting the bitumen and any remaining amounts of
the first solvent in the pipe extractor with LPG.
[0182] The results of the extraction process are shown in Table
8Table. The total weight loss is the difference between the weight
of the tar sands feedstock and the weight of the second solvent-wet
tailings component removed from the pipe extractor. The American
Petroleum Institute (API) gravity was determined for the liquid
extracted from the pipe extractor. The second solvent-wet tailings
removed from the pipe extractor were analyzed using the Dean-Stark
apparatus to determine the amount of bitumen in the second
solvent-wet tailings.
[0183] The amount of bitumen in the tar sands feedstock can be
calculated using this equation: bitumen in tar sands feedstock (wt
%)=total weight loss (wt %)-water in tar sands feedstock (wt
%)+(100-total weight loss (wt %))*fraction of bitumen in second
solvent-wet tailings. Using sample T-1 as an example, the
calculation was as follows: Bitumen in tar sands feedstock (wt
%)=18.13-4.6+(100-18.13)*0.0205. The percent of the bitumen that
was extracted can then be calculated using this equation: (bitumen
in tar sands feedstock (wt %)-(100-total weight loss (wt
%))*fraction of bitumen in second solvent-wet tailings)/bitumen in
tar sands feedstock (wt %). Using sample T-1 as an example, the
calculation was as follows: (15.20-(100-18.13)*0.0205)/15.20.
TABLE-US-00009 TABLE 7 Trinidad Extraction Process Parameters
Description First S:B First Second Sample Solvent Ratio Extraction
Extraction T-1 Biodiesel 14:1 1 hour filtration T-2 Toluene 5:1 4-5
hour filtration Filter cake solids compacted in pipe T-3 Toluene
20:1 Toluene flow slow out of pipe, very compact cake T-4 Xylene
10:1 Filtered overnight Solids poured out easily T-5 Toluene 10:1
3-5 minute filtration No liquid from pipe T-6 Light 10:1 3-5 minute
filtration, Sands easily removed, high Distillate* dry filter cake
viscosity liquid recovered T-7 Light 10:1 20 minute filtration,
Sands easily removed low Distillate* wet filter cake viscosity
liquid recovered T-8 Light 5:1 3-5 minute filtration, Sands removed
as one big Distillate* wet filter cake clump, low viscosity liquid
recovered T-9 Light 10:1 First extraction: LPG resulted in
compacted cake Distillate* Second extraction: filtered first
solvent for one hour Third extraction: sands removed easily, low
viscosity liquid T-10 Naphtha 10:1 3-5 minute filtration, Solids
removed very easily dry filter cake T-11 Naphtha 5:1 3-5 minute
filtration, Solids removed very easily dry filter cake *Light
distillate solvent used has an API gravity of approximately 30. The
light distillate includes highly aromatic compounds such as
toluene, xylene, some benzene, and other ring compounds. The light
distillate was obtained by steam cracking bitumen as described in
U.S. Patent Application Publication No. 2006/0144760.
TABLE-US-00010 TABLE 8 Trinidad Extraction Results Bitumen in API
Gravity Bitumen in Second Tar Sands Total Bitumen Weight of
Extracted Solvent-Wet Feedstock Extracted Sample Loss (%) Liquid
Tailings (wt %) (wt %) (wt %) T-1 18.1 21.0 2.1 15.2 88.9 T-2 17.6
-- -- -- -- T-3 18.1 23.1 -- -- -- T-4 17.5 -- -- -- -- T-5 18.0 --
-- -- -- T-6 14.1 9.2 2.6 11.7 81.3 T-7 14.7 9.8 3.3 12.9 78.3 T-8
15.3 21.5 3.3 13.4 79.2 T-9 18.4 28.5 4.8 17.7 78.0 T-10 14.7 -- --
-- -- T-11 17.2 -- 1.7 13.9 90.2
[0184] The bitumen-enriched solvent phase obtained from sample T-8
was preheated to a temperature of 400.degree. C. using a sand bath
heater. The bitumen-enriched solvent phase was then injected into a
nozzle reactor of the type described in U.S. Patent Application
Publication No. 2006/0144760. The bitumen-enriched solvent phase
was injected into the nozzle reactor via the material feed port of
the nozzle reactor. Steam at a pressure of 20 bar was also injected
into the nozzle reactor via a injection passage positioned
transverse to the material feed passage. Steam and bitumen-enriched
solvent phase were injected into the nozzle reactor at a
steam:bitumen-enriched solvent phase at a ratio of 2:1. The
pressure inside of the nozzle reactor at injection was 1.5 bar. The
dimensions of the nozzle are set forth in Table 9. The injected
bitumen-enriched solvent phase remained in the nozzle reactor for a
period of about 1 second.
TABLE-US-00011 TABLE 9 Nozzle Reactor Component (mm) Injection
Passage, Enlarged Volume 148 Injection Section Diameter Injection
Passage, Reduced Volume 50 Mid-Section Diameter Injection Passage,
Enlarged Volume 105 Ejection Section Diameter Injection Passage
Length 600 Interior Reactor Chamber 187 Injection End Diameter
Interior Reactor Chamber 1,231 Ejection End Diameter Interior
Reactor Chamber Length 6,400 Overall Nozzle Reactor Length 7,000
Overall Nozzle Reactor Outside 1,300 Diameter
[0185] A liquid product exiting the nozzle reactor was collected
and analyzed. The product was separated into a non-participating
hydrocarbon stream and a participating hydrocarbon stream. The
participating hydrocarbon stream had an API gravity in the range of
from 28-35. The participating hydrocarbon stream contained a
mixture of cracked hydrocarbons. The mixture included highly
aromatic compounds such as toluene, xylene, some benzene, and other
ring compounds. The molecular weight of the compounds in the
participating hydrocarbon stream generally were less than 300
Daltons. The participating hydrocarbon stream was classified as a
light distillate of the type usable as a first solvent in a solvent
extraction step of the method described above.
Example 2
AthHG Tar Sands
[0186] In this example, Bitumen was extracted from a total of four
samples of high grade Athabasca tar sands. The samples are
designated AHG-1 through AHG-4 in Table 10. The details of the
extraction of each sample can be found in Table 10 along with some
observations taken during each process.
[0187] The same general procedure outlined in Example 1 was used to
extract bitumen from the high grade Athabasca tar sands samples
with a few minor exceptions. Some of the samples were mixed with a
bowtie shaped coil impeller instead of the three blade impeller.
The coil impeller was used to ensure adequate mixing and dispersion
of the large pieces of clay in the samples. The samples mixed with
the coil impeller are noted in Table 10.
[0188] In general, it was more difficult to quickly and efficiently
filter the high grade Athabasca tar sands than the Trinidad tar
sands. For example, Sample AHG-1 did filter, but it was left
overnight and there was no loose liquid remaining with the filter
cake by morning. Also, Sample AHG-2 used the coil impeller which
helped it to filter steadily but it was still somewhat slow. Sample
AHG-4 was similar to Samples AHG-1 and AHG-3 except there was no
loose liquid with the filter cake when it was placed in the pipe
extractor. The results of the extraction process are shown in Table
11. It should be noted that Table 11 also shows the API gravity of
the liquid filtrate resulting from the first extraction
process.
TABLE-US-00012 TABLE 10 AthHG Extraction Process Parameters
Description First S:B First Second Sample Solvent Ratio Extraction
Extraction AHG-1 Light 5:1 Filtered Solids removed Distillate
overnight, moist easily filter cake AHG-2 Biodiesel 5:1 Mixed with
coil Solids were impeller, two slightly packed hour atm filter*
AHG-3 Light 5:1 Mixed with coil Liquid removed Distillate impeller,
atm during N2 purge filtered overnight*, very moist filter cake
AHG-4 Light 5:1 Filters slow Solids were Distillate quite dark
*Filtered using Buchner filter with paper at atmospheric pressure
(i.e., no vacuum).
TABLE-US-00013 TABLE 11 AthHG Extraction Results API API Gravity
Bitumen in Bitumen in Total Bitumen Weight Gravity of Extracted
Residual Tar Feedstock Extracted Sample Loss (%) of Filtrate Liquid
Sands (wt %) (wt %) (wt %) AHG-1 17.3 28.4 39.5 1.9 16.7 90.7 AHG-2
19.6 28.5 29.6 1.7 17.0 91.7 AHG-3 16.9 29.8 26.5 2.3 14.9 87.1
AHG-4 17.0 31.5 29.9 2.4 14.9 86.7
[0189] The bitumen-enriched solvent phase obtained from sample
AHG-1 was preheated to a temperature of 400.degree. C. using a sand
bath heater. The bitumen-enriched solvent phase was then injected
into a nozzle reactor of the type described in U.S. Patent
Application Publication No. 2006/0144760. The bitumen-enriched
solvent phase was injected into the nozzle reactor via the material
feed port of the nozzle reactor. Steam at a pressure of 20 bar was
also injected into the nozzle reactor via an injection passage
positioned transverse to the material feed passage. Steam and
bitumen-enriched solvent phase were injected into the nozzle
reactor at a steam:bitumen-enriched solvent phase at a ratio of
2:1. The pressure inside of the nozzle reactor at injection was 1.5
bar. The dimensions of the nozzle are set forth in Table 9 above.
The injected bitumen-enriched solvent phase remained in the nozzle
reactor for a period of about 1 second.
[0190] A liquid product exiting the nozzle reactor was collected
and analyzed. The product was separated into a non-participating
hydrocarbon stream and a participating hydrocarbon stream. The
participating hydrocarbon stream had an API gravity of
approximately 28. The participating hydrocarbon stream contained a
mixture of cracked hydrocarbons. The mixture included highly
aromatic compounds such as toluene, xylene, some benzene, and other
ring compounds. The molecular weight of the compounds in the
participating hydrocarbon stream generally were less than 300
Daltons. The participating hydrocarbon stream was classified as a
light distillate of the type usable as a first solvent in a solvent
extraction step of the method described above.
Example 3
AthLG Tar Sands
[0191] In this example, Bitumen was extracted from a total of four
samples of low grade Athabasca tar sands. The samples are
designated ALG-1 through ALG-8 in Table 12. The details of the
extraction of each sample can be found in Table 12 along with some
observations taken during each process.
[0192] The same general procedure outlined in Example 1 was used to
extract bitumen from the low grade Athabasca tar sands samples with
a few minor exceptions. Sample ALG-4 did not undergo the first
extraction process and instead was put directly into the pipe
extractor. No liquid was recovered from the second extraction
process (LPG extraction process) for Sample ALG-2. Sample ALG-3
used biodiesel as the first solvent and was able to filter fast. A
coil impeller was used to mix the first solvent and the tar sands.
The mixture was subjected to a thirty minute vacuum filtration and
thirty minute atmospheric filtration. The filter cake was allowed
to air dry under room temperature overnight before entering the
pipe extractor. The solids were removed from the pipe extractor
quite easily. The low grade Athabasca tar sands was easily
processed though the system. The results of the extraction process
are shown in Table 13.
TABLE-US-00014 TABLE 12 AthLG Extraction Process Parameters
Description First First Second Sample Solvent Ratio Extraction
Extraction ALG-1 Light 6:1 Filters very fast Solids removed
Distillate easily, light liquid ALG-2 Naphtha 6:1 Filtered
instantly Solids removed easily, no liquid capture ALG-3 Biodiesel
6:1 Filtered fast Few chunks of dark solids ALG-4 -- 20:1 -- Solids
were tightly packed in the pipe, minimal liquid recovered ALG-5
Light 5:1 Filtered instantly, Solids removed Distillate heavy
filter cake easily ALG-6 Light 5:1 Filtered instantly, Solids
removed Distillate heavy filter cake easily ALG-7 Light 5:1 Dry
feed, filtered Lots of liquid Distillate for 2 days but still
recovered moist, very compact dark filter cake ALG-8 Light 5:1
Filtered fast Solids were very Distillate dry, no large clumps of
asphaltenes, few pellets of clay
TABLE-US-00015 TABLE 13 AthLG Extraction Results API API Gravity
Bitumen in Bitumen in Total Bitumen Weight Gravity of Extracted
Residual Tar Feedstock Extracted Sample Loss (%) of Filtrate Liquid
Sands (wt %) (wt %) (wt %) ALG-1 13.7 31.6 42.1 1.4 8.4 85.9 ALG-2
15.2 54.5 -- -- -- -- ALG-3 16.5 48.1 13.9 -- -- -- ALG-4 10.8 --
13.9 8.0 11.4 37.8 ALG-5 11.0 32.1 38.3 3.2 7.4 61.3 ALG-6 13.1
29.2 29.1 2.7 8.9 73.9 ALG-7 6.2 27.4 26.9 6.0 11.2 49.8 ALG-8 10.0
27.8 31.5 2.1 69.3 64.2
The bitumen-enriched solvent phase obtained from sample ALG-1 was
preheated to a temperature of 400.degree. C. using a sand bath
heater. The bitumen-enriched solvent phase was then injected into a
nozzle reactor of the type described in U.S. Patent Application
Publication No. 2006/0144760. The bitumen-enriched solvent phase
was injected into the nozzle reactor via the material feed port of
the nozzle reactor. Steam at a pressure of 20 bar was also injected
into the nozzle reactor via an injection passage positioned
transverse to the material feed passage. Steam and bitumen-enriched
solvent phase were injected into the nozzle reactor at a
steam:bitumen-enriched solvent phase at a ratio of 2:1. The
pressure inside of the nozzle reactor at injection was 1.5 bar. The
dimensions of the nozzle are set forth in Table 9 above. The
injected bitumen-enriched solvent phase remained in the nozzle
reactor for a period of about 1 second.
[0193] A liquid product exiting the nozzle reactor was collected
and analyzed. The product was separated into a non-participating
hydrocarbon stream and a participating hydrocarbon stream. The
participating hydrocarbon stream had an API gravity of
approximately 28. The participating hydrocarbon stream contained a
mixture of cracked hydrocarbons. The mixture included highly
aromatic compounds such as toluene, xylene, some benzene, and other
ring compounds. The molecular weight of the compounds in the
participating hydrocarbon stream generally were less than 300
Daltons. The participating hydrocarbon stream was classified as a
light distillate of the type usable as a first solvent in a solvent
extraction step of the method described above.
[0194] As used herein, spatial or directional terms, such as
"left," "right," "front," "back," and the like, relate to the
subject matter as it is shown in the drawing Figures. However, it
is to be understood that the subject matter described herein may
assume various alternative orientations and, accordingly, such
terms are not to be considered as limiting. Furthermore, as used
herein (i.e., in the claims and the specification), articles such
as "the," "a," and "an" can connote the singular or plural. Also,
as used herein, the word "or" when used without a preceding
"either" (or other similar language indicating that "or" is
unequivocally meant to be exclusive--e.g., only one of x or y,
etc.) shall be interpreted to be inclusive (e.g., "x or y" means
one or both x or y). Likewise, as used herein, the term "and/or"
shall also be interpreted to be inclusive (e.g., "x and/or y" means
one or both x or y). In situations where "and/or" or "or" are used
as a conjunction for a group of three or more items, the group
should be interpreted to include one item alone, all of the items
together, or any combination or number of the items. Moreover,
terms used in the specification and claims such as have, having,
include, and including should be construed to be synonymous with
the terms comprise and comprising.
[0195] Unless otherwise indicated, all numbers or expressions, such
as those expressing dimensions, physical characteristics, etc.,
used in the specification (other than the claims) are understood as
modified in all instances by the term "approximately." At the very
least, and not as an attempt to limit the application of the
doctrine of equivalents to the claims, each numerical parameter
recited in the specification or claims which is modified by the
term "approximately" should at least be construed in light of the
number of recited significant digits and by applying ordinary
rounding techniques.
[0196] In addition, all ranges disclosed herein are to be
understood to encompass and provide support for claims that recite
any and all subranges or any and all individual values subsumed
therein. For example, a stated range of 1 to 10 should be
considered to include and provide support for claims that recite
any and all subranges or individual values that are between and/or
inclusive of the minimum value of 1 and the maximum value of 10;
that is, all subranges beginning with a minimum value of 1 or more
and ending with a maximum value of 10 or less (e.g., 5.5 to 10,
2.34 to 3.56, and so forth) or any values from 1 to 10 (e.g., 3,
5.8, 9.9994, and so forth).
* * * * *