Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02787798 2013-05-13
BITUMINOUS FROTH INCLINED PLATE SEPARATOR AND HYDROCARBON
2 CYCLONE TREATIVLENT PROCESS
3 Related Applications
4
This application is a divisional application of application serial number
2,761,345, which
is a divisional application.of patent no. 2,471,048, which is a divisional
application of
6 patent no. 2,400,258 filed September 19, 2002.
7 Field of the invention
8 This invention relates to bitumen recovery from oil sand and more
particularly to a treatment
9 process for the removal of water and mineral from the product produced in
a primPry oil sand
' 10 bitumen extraction process.
11 Background to the Invention
12 Oil sands are a geological formation, which are also known as tar sands
or bituminous sands.
13 The oil sands deposits provide aggregates of solids such as sand, clay
mineral plus water and
14 bitumen - a term for extra heavy oil. Significant deposits of oil sands
are found in Northern
Alberta in Canada and extend across an area of more than thirteen thousand
square miles. The
16 oil sands formation extends from the surface or zero depth to depths of
two thousand feet below
17 overburden. The oil sands deposits are measured in billions of barrels
equivalent of oil and
18 represent a significant portion of the worldwide reserves of
conventional and non-conventional
19 oil reserves.
The oil sands deposits are composed primarily of particulate silica mineral
material. The
21 bitumen content varies from about 5% to 21% by weight of the formation
material, with atypical.
22 content of about 12% by weight. The mineral portion of the oil sands
formations generally
23 includes clay and silt ranging from about 1% to 50% by -weight and more
typically 10% to 30%
24 by weight as well as a small amount of water in quantities ranging
between 1% and 10% by
weight. The in-situ bitumen is quite viscous, generally has an API gravity of
about 6 degrees to
26 8 degrees and typically includes 4% to 5% sulfur with approximately 38%
aromatics.
214763E3.1 1
CA 02787798 2012-08-17
1 The Athabasca oil sands are bitumen-bearing sands, where the bitumen is
isolated from the sand
2 by a layer of water forming a water-wet tar sand. Water-wet tar sand is
almost unique to the
3 Athabasca oil sands and the water component is frequently termed connate
water. Sometimes
4 the term water-wet is used to describe this type of tar sand to
distinguish it from the oil-wet sand
deposits found more frequently in other tar sand formations and in shale
deposits including those
6 oily sands caused by oil spills.
7 The extraction of the bitumen from the sand and clay-like mineral
material is generally
8 accomplished by heating the composition with steam and hot water in a
rotating vessel or drum
9 and introducing an extraction agent or process aid. The process aid
typically is sodium
hydroxide NaOH and is introduced into the processing to improve the separation
and recovery of
11 bitumen particularly when dealing with difficult ores. The hot water
process is carried out in a
12 vessel called a separator cell or more specifically a primary separator
vessel (PSV) after the oil
13 sand has been conditioned in the rotating drum.
14 The PSV process produces a primary bitumen froth gathered in a launder
from the upper
perimeter of the vessel; a mineral tailings output from the lower portion of
the vessel and a
16 middlings component that is removed from the mid-portion of the vessel.
It has been found that
17 production of the middlings component varies with the fines and clay
content of the Originating
18 oil sand and is described more fully, for example in Canadian patent
857,306 to Dobson. The
19 middlings component contains an admixture of bitumen traces, water and
mineral material in
suspension. The middlings component is amenable to secondary separation of the
bitumen it
21 contains, by introducing air into the process flow in flotation cells.
The introduced air causes the
22 bitumen to be concentrated at the surface of the flotation cell. The
flotation of the bitumen in
23 preference to the solids components permits the air entrained bitumen to
be extracted from the
24 flotation cell. Flotation of the air-entrained bitumen from the process
flow is sometimes termed
differential flotation. The air-entrained bitumen froth is also referred to as
secondary froth and is
26 a mixture of the bitumen and air that rises to the surface of the
flotation cell. Typically, the
27 secondary froth may be further treated, for example by settling, and is
recycled to the PSV for
28 reprocessing.
21476383.1 2
CA 02787798 2012-08-17
1 Further treatment of the primary bitumen froth from the PSV requires
removal of the mineral
solids, the water and the air from the froth to concentrate the bitumen
content. Conventionally,
3 this is done by the use of centrifuges. Two types of centrifuge systems
have heretofore been
4 deployed. One, called a solids-bowl centrifuge has been used to reduce
the solids in froth
substantially. To remove water and solids from the froth produced by a solids-
bowl centrifuge; a
6 secondary centrifuge employing a disk has been used. Disk centrifuges
are principally de-
7 watering devices, but they help to remove mineral as well. Examples of
centrifuge systems that
8 have been deployed are described in Canadian patents 873,854; 882,667;
910,271 and 1,072,473.
9 The Canadian patent 873,854 to Baillie for example, provides a two-stage
solid bowl and disk
centrifuge arrangement to obtain a secondary bitumen froth from the middlings
stream of a
11 primary separation vessel in the hot water bitumen recovery process. The
Canadian patent
12 882,667 to Daly teaches diluting bitumen froth with a naphtha diluent
and then processing the
13 diluted bitumen using a centrifuge arrangement.
14 Centrifuge units require an on-going expense in terms of both capital
and operating costs.
Maintenance costs are generally high with centrifuges used to remove water and
solid minerals
16 from the bitumen froth. The costs are dictated by the centrifuges
themselves, which are
,. 17 mechanical devices having moving parts that rotate at high speeds and
have substantial
18 momentum. Consequently, by their very nature, centrifuges require a lot
of maintenance and are
19 subject to a great deal of -wear and tear. Therefore, elimination of
centrifuges from the froth
treatment process would eliminate the maintenance costs associated with this
form of froth
21 treatment. Additional operating cost results from the power cost
required to generate the high g-
22 forces in large slurry volumes.
23 In the past, cyclones of conventional design have been proposed for
bitumen froth treatment, for
24 example in Canadian patents 1,026,252 to Lupu1 and 2,088,227 to Gregoli.
However, a basic
problem is that recovery of bitumen always seems to be compromised by the
competing
26 requirements to reject water and solids to tailings while maintaining
maximum hydrocarbon
27 recovery. In practice, processes to remove solids and water from bitumen
have been offset by
28 the goal of maintaining maximal bitumen recovery. Cyclone designs
heretofore proposed tend to
29 allow too much water content to be conveyed to the overflow product
stream yielding a poor
bitumen-water separation. The arrangement of Lupul is an example of use of off-
the-shelf
21473g3.1 3
CA 02787798 2012-08-17
1 cyclones that accomplish high bitumen recovery, unfortunately with low
water rejection. The
2 low water rejection precludes this configuration from being of use in a
froth treatment process, as
3 too much of the water in the feed stream is passed to the overflow or
product stream.
4 A hydrocyclone arrangement is disclosed in Canadian patent 2,088,227 to
Gregoli. Gregoli
teaches alternative arrangements for cyclone treatment of non-diluted bitumen
froth. The
6 hydrocyclone arrangements taught by Gregoli attempt to replace the
primary separation vessel of
7 a conventional tar sand hot water bitumen processing plant with
hydrocyclones. The process
8 arrangement of Gregoli is intended to eliminate conventional primary
separation vessels by
9 supplanting them with a hydrocyclone configuration. This process requires
an unconventional
upgrader to process the large amounts of solids in the bitumen product
produced by the apparatus
11 of Gregoli. Gregoli teaches the use of chemical additive reagents to
emulsify high bituminous
12 slurries to retain water as the continuous phase of emulsion. This
provides a low viscosity slurry
13 to prevent the viscous plugging in the hydrocyclones that might
otherwise occur. Without this
14 emulsifier, the slurry can become oil-phase continuous, which will
result in several orders of
magnitude increase in viscosity. Unfortunately, these reagents are costly
making the process
16 economically unattractive.
17 Another arrangement is disclosed in Canadian patent 2,029,756 to Sury,
which describes an
18 apparatus having a central overflow conduit to separate extracted or
recovered bitumen from a
19 froth fluid flow. The apparatus of Sury is, in effect, a flotation cell
separator in which a feed
material rotates about a central discharge outlet that collects a launder
overflow. The
21 arrangement of Sury introduces process air to effect bitumen recovery
and is unsuitable for use
22 in a process to treat deaerated naphtha-diluted-bitumen froth as a
consequence of explosion
23 hazards present with naphtha diluents and air.
24 Other cyclone arrangements have been proposed for hydrocarbon process
flow separation from
gases, hot gases or solids and are disclosed for example in Canadian patents
1,318,273 to
26 Mundstock et al; 2,184,613 to Raterman et al and in Canadian published
patent applications
27 2,037,856; 2,058,221; 2,108,521; 2,180,686; 2,263,691, 2,365,008 and the
hydrocyclone
28 arrangements of Lavender et al in Canadian patent publications
2,358,805, 2,332,207 and
29 2,315,596.
21476383.1 4
CA 02787798 2012-08-17
1
2 Summary of the invention
3 In the following narrative wherever the term bitumen is used the term
diluted bitumen is implied.
4 This is because the first step of this froth treatment process is the
addition of a solvent or diluent
such as naphtha to reduce viscosity and to assist hydrocarbon recovery. The
term hydrocarbon
6 could also be used in place of the word bitumen for diluted bitumen.
7 The present invention provides a bitumen froth process circuit that uses
an arrangement of
8 hydrocarbon cyclones and inclined plate separators to perform removal of
solids and water from
9 the bitumen froth that has been diluted with a solvent such as naphtha.
The process circuit has an
inclined plate separator and hydrocarbon cyclone stages. A circuit configured
in accordance with
11 the invention provides a process to separate the bitumen from a hybrid
emulsion phase in a
12 bitumen froth. The hybrid emulsion phase includes free water and a water-
in-oil emulsion and
13 the circuit of the present invention removes minerals such as silica
sand and other clay minerals
14 entrained in the bitumen froth and provides the removed material at a
tailings stream provided at
a circuit tails outlet. The process of the invention operates without the need
for centrifuge
16 equipment. The elimination of centrifuge equipment through use of
hydrocarbon cyclone and
17 inclined plate separator equipment configured in accordance with the
invention provides a cost
18 saving in comparison to a process that uses centrifuges to effect,
bitumen de-watering and
19 demineralization. However, the process of the invention can operate with
centrifuge equipment
to process inclined plate separator underflow streams if so desired.
21 The apparatus of the invention provides an inclined plate separator
(IPS) which operates to
22 separate a melange of water-continuous and oil-continuous emulsions into
a cleaned oil product
23 and underflow material that is primarily a water-continuous emulsion.
The cyclone apparatus
24 processes a primarily water-continuous emulsion and creates a product
that constitutes a melange
of water-continuous and oil-continuous emulsions separable by an IPS unit.
When the apparatus
26 of the invention is arranged with a second stage of cyclone to process
the underflow.of a first
27 stage cyclone, another product stream, separable by an LPS unit can be
created along with a
28 cleaned tails stream.
21476383.1 5
CA 02787798 2012-08-17
=
1 -- In accordance with the invention, the bitumen froth to be treated is
supplied to a circuit inlet for
2 -- processing into a bitumen product provided at a circuit product outlet
and material removed from
3 -- the processed bitumen froth is provided at a circuit tails outlet. The
bitumen froth is supplied to
4 -- a primary inclined plate separator (IPS) stage, which outputs a bitumen
enhanced overflow
-- stream and a bitumen depleted underflow stream. The underflow output stream
of the first
6 -- inclined plate separator stage is a melange containing a variety of
various emulsion components
7 -- supplied as a feed stream to a cyclone stage. The cyclone stage outputs a
bitumen enhanced
8 -- overflow stream and a bitumen depleted underflow stream. The formation of
a stubborn
9 -- emulsion layer can block the downward flow of water and solids resulting
in poor bitumen
-- separation. These stubborn emulsion layers are referred to as rag-layers.
The process of the
11 -- present invention is resistant to rag-layer formation within the
inclined plate separator stage,
12 -- which is thought to be a result of the introduction of a recycle feed
from the overflow stream of
13 -- the hydrocarbon cyclone stage.
14 -- The material of the recycle feed is conditioned in passage through a
hydrocarbon cyclone stage.
-- When the recycle material is introduced into the inclined plate separator
apparatus, a strong
16 -- upward bitumen flow is present even with moderate splits. Static
deaeration, that is removal of
17 -- entrained air in the froth without the use of steam, is believed to be
another factor that promotes
18 -- enhanced bitumen-water separation within the inclined plate separators.
A bitumen froth that has
19 -- been deaerated without steam is believed to have increased free-water in
the froth mixture
-- relative to a steam deaerated froth., thus tending to promote a strong
water flow in the underflo-w
21 -- direction, possibly due to increased free-water in the new feed. In a
process arranged in
22 accordance with this invention distinct rag-layers are not manifested in
the compression or
23 -- underflow zones of the EPS stages.
24 -- The underflow output stream of the first inclined plate separator stage
is supplied to a primary
-- hydrocarbon cyclone stage, which transforms this complex mixture into an
emulsion that is
26 -- available from the primary cyclone stage as an overflow output stream.
In a preferred
27 -- arrangement, the overflow output stream of the primary cyclone stage is
supplied to an IPS stage
28 -- to process the emulsion. The overflow output stream of an TIPS stage
provides a bitumen product
29 -- that has reduced the non-bitumen components in an effective manner.
214763E3.1 6
CA 02787798 2012-08-17
1 The hydrocarbon cyclone apparatus of the present invention has a long-
body extending between
2 an inlet port and a cyclone apex outlet, to which the output underflow
stream is directed, and an
3 abbreviated vortex finder to which the output overflow stream is
directed. This configuration
4 permits the cyclone to reject water at a high percentage to the underflow
stream output at the
apex of the cyclone. This is accomplished in process conditions that achieve a
high hydrocarbon
6 recovery to the overflow stream, which is directed to the cyclone vortex
finder, while still
7 rejecting most of the water and minerals to the apex underflow stream.
Mineral rejection is
8 assisted by the hydrophilic nature of the mineral constituents. The
cyclone has a shortened or
9 abbreviated vortex finder, allowing bitumen to pass directly from the
input bitumen stream of the
cyclone inlet port to the cyclone vortex finder to which the output overflow
stream is directed.
11 The long-body configuration of the cyclone facilitates a high water
rejection to the apex
12 underflow. Thus, the normally contradictory goals of high hydrocarbon
recovery and high
13 rejection of other components are simultaneously achieved.
14 The general process flow of the invention is to supply the underflow of
an inclined plate
separator stage to a cyclone stage. To have commercial utility, it is
preferable for the cyclone
16 units to achieve water rejection. Water rejection is simply the recovery
of water to the underflow
17 or reject stream.
18 In addition to the unique features of the hydrocarbon cyclone apparatus
the process units of this
19 invention interact with each other in a novel arrangement to facilitate
a high degree of
constituent material separation to be achieved. The bitumen froth of the
process stream
21 emerging as the cyclone overflow is conditioned in passage through the
cyclone to yield over
22 90% bitumen recovery when the process stream is recycled to the primary
inclined plate
23 separator stage for further separation. Remarkably, the resultant water
rejection on a second pass
24 through the primary cyclone stage is improved over the first pass. These
process factors
combine to yield exceptional bitumen recoveries in a circuit providing an
alternate staging of an
26 inclined plate separator stage and a cyclone stage where the bitumen
content of the output
27 bitumen stream from the circuit exceeds 98.5% of the input bitumen
content. Moreover, the
28 output bitumen stream provided at the circuit product outlet has a
composition suitable for
29 upgrader processing.
21476383.1 7
CA 02787798 2013-05-13
1 In a
further aspect of the present invention there is provided a system for
processing a
2
bitumen feed comprising a mixture of bitumen, water and mineral. The system
may
3 comprise:
4 a
first separation stage comprising a first inclined plate separator operative
to
separate bitumen from the bitumen feed to produce a first overflow stream
6 and a
first underflow stream, the first overflow stream comprising a first
7
bitumen enriched stream and the first underflow stream comprising a first
8 bitumen reduced stream;
9 a
second separation stage comprising a first plurality of cyclones operative to
separate bitumen from the first underflow stream to produce a second
11
overflow stream and a second underflow stream, the second overflow
12 stream
comprising a second bitumen enriched stream and the second
13
underflow stream comprising a second bitumen reduced stream, wherein
14 each of the first plurality of cyclones comprises:
a first cyclone body having a first elongated conical inner surface defining
16 a
first cyclone cavity extending from a first upper inlet region with
17 a
first diameter DC1 to a first lower apex outlet with a first
18
diameter DUI, wherein the first diameter DC1 is not less than about
19 150mm
and not more than about 200mm and the first diameter
DUI is not less than about 40mm and not more than about 50mm;
21 a
first inlet forming a first inlet channel with a first diameter DI1 extending
22 into
the first upper inlet region of the first cyclone cavity, wherein
23 the
first inlet channel forms a first involute path into the first
24
cyclone cavity and the first diameter DI1 is approximately 50 mm
or less; and
26 a
first vortex finder forming a first overflow outlet of a first diameter DOI
27
extending into the first upper inlet region of the first cyclone cavity
28 toward
the first lower apex outlet and having a first lower end
7a
CA 02787798 2013-05-13
1
extending a first excursion distance below the first inlet channel,
2
wherein the first lower end of the first vortex finder within the first
3
cyclone cavity is disposed a first free vortex height (FV1-11)
4
distance from the first lower apex outlet and wherein the first
diameter DOI is approximately 50mm or less and the first FV1-11
6
distance is not less than about 1133mm and not more than about
7 1821mm;
8 a
third separation stage comprising a second plurality of cyclones operative to
9
separate bitumen from the second underflow stream to produce a third
overflow stream and a third underflow stream, the third overflow stream
11
comprising a third bitumen enriched stream and the third underflow
12 stream comprising a third bitumen reduced stream;
13 a
first diverter for diverting at least a first portion of the second overflow
stream
14 to
modulate modulating a composition of at least the first portion of the
second overflow stream and the third overflow stream to form a first
16 recycle stream; and
17 a
first recycling circuit for recycling the first recycle stream to the first
separation
18 stage for further processing by the first inclined plate
separator.
19 The
system may further comprise a fourth separation stage operative to separate
bitumen
from at least a second portion of the second overflow stream to produce a
fourth overflow
21 stream
and a fourth underflow stream, the fourth overflow stream comprising a fourth
22
bitumen enriched stream and the fourth underflow stream comprising a fourth
bitumen
23 reduced stream.
24 The fourth separation stage may comprise a second inclined plate
separator.
The fourth separation stage may comprise a first centrifuge for processing the
second
26 portion of the second overflow stream.
7b
CA 02787798 2013-05-13
I The system may further comprise a fifth separation stage operative to
separate bitumen
2 from at least a third portion of the second overflow stream to produce a
fifth overflow
3 stream and a fifth underflow stream, the fifth overflow stream comprising
a fifth bitumen
4 enriched stream and the fifth underflow stream comprising a fifth bitumen
reduced
stream.
6 The fifth separation stage may comprise a second centrifuge for
processing the third
7 portion of the second overflow stream.
8 The first overflow stream may comprise a first diluted bitumen product
stream.
9 The fourth overflow stream may comprise a second diluted bitumen product
stream.
The fifth overflow stream may comprise a third diluted bitumen product stream.
11 The third underflow stream may form a first tailings stream.
12 The fifth underflow stream may form a second tailings stream.
13 The third bitumen reduced stream may have less bitumen than the first
bitumen reduced
14 stream.
The third bitumen reduced stream may have less bitumen that the second bitumen
16 reduced stream.
17 The third bitumen reduced stream may have less bitumen that the fourth
bitumen reduced
18 stream.
19 The first bitumen reduced stream may have more bitumen than the second
bitumen
reduced stream.
21 The first bitumen reduced stream may have more bitumen than the fourth
bitumen
22 reduced stream.
23 The solvent may comprise a paraffinic solvent.
24 The solvent may comprise naphtha.
7c
CA 02787798 2013-05-13
1 The first diluted bitumen product stream may comprise approximately 34%
or more
2 solvent by weight.
3 The first diluted bitumen product stream may comprise approximately 2.1%
or less water
4 by weight.
The first diluted bitumen product stream may comprise approximately 97% or
more
6 hydrocarbon by weight.
7 The first diluted bitumen product stream may comprise approximately 1.2%
or less solids
8 by weight.
9 The first and second diluted bitumen product streams in combination may
comprise
approximately 34% or more solvent by weight, approximately 2.1% or less water
by
11 weight, approximately 97% or more hydrocarbon by weight and
approximately 1.2% or
12 less solids by weight.
13 The first, second and third diluted bitumen product streams in
combination may comprise
14 approximately 34% or more solvent by weight, approximately 2.1% or less
water by
weight, approximately 97% or more hydrocarbon by weight and approximately 1.2%
or
16 less solids by weight.
17 The bitumen feed may comprise a hybrid emulsion phase comprising a
mélange of water-
18 continuous and oil-continuous emulsions.
19 The first underflow stream comprises a water-continuous emulsion.
The bitumen feed may comprise a bitumen froth formed by an oil sands
extraction
21 process.
22 In a further aspect of the system, each of the second plurality of
cyclones may comprise:
23 a
second cyclone body having a second elongated conical inner surface defining a
24 second
cyclone cavity extending from a second upper inlet region with a
second diameter DC2 to a second lower apex outlet with a second diameter
7d
CA 02787798 2013-05-13
1 DU2,
wherein the second diameter DC2 is not less than about 150mm and
2 not
more than about 200mm and the second diameter DU2 is not less than
3 about 40mm and not more than about 50mm;
4 a
second inlet forming a second inlet channel with a second diameter DI2
extending into the second upper inlet region of the second cyclone cavity,
6
wherein the second inlet channel forms a second involute path into the
7 second
cyclone cavity and the second diameter DI,' is approximately 50
8 mm or less; and
9 a
second vortex finder forming a second overflow outlet of a second diameter
DO2 extending into the second upper inlet region of the second cyclone
11 cavity
toward the second lower apex outlet and having a second lower end
12
extending a second excursion distance below the second inlet channel,
13
wherein the second lower end of the second vortex finder within the
14 second
cyclone cavity is disposed a second free vortex height (FV1-17)
distance from the second lower apex outlet and wherein the second
16
diameter DO2 is approximately 50mm or less and the second FVH2
17 distance is not less than about 1133mm and not more than about
1821mm.
18 The
system may further comprise a portion of the bitumen in the second underflow
19 stream
that passes through the second inlet channel of at least one of the second
plurality
of cyclones exits the at least one of the second plurality of cyclones as part
of the third
21
overflow stream without having to make a spiral journey down the second
cyclone cavity.
22 The
portion of the bitumen in the second undertlow stream may exit the at least
one of
23 the
second plurality of cyclones through the second overflow outlet after one and
one half
24 revolutions.
The second inlet channel may be shaped such that a diameter of the second
involute path
26 of the
second inlet channel narrows along the second involute path as the second
inlet
27 channel approaches a central location proximate the second vortex
finder.
7e
CA 02787798 2013-05-13
1 The system may further comprise a reflection of a second descending helix
vortex fluid
2 flowing into a second ascending helix vortex fluid flow forms in a
central zone near the
3 second lower apex outlet of the second cyclone cavity.
4 The system may further comprise a second central vapour core extending
along an axis of
the second cyclone body.
6 The second central vapour core may be only millimeters in diameter and is
sized
7 sufficiently to cause about 3% to about 4% enrichment in a solvent to
bitumen ratio of the
8 third overflow stream.
9 The system may further comprise a portion of the bitumen in the first
underflow stream
that passes through the first inlet channel of at least one of the first
plurality of cyclones
11 exits the at least one of the first plurality of cyclones as part of the
second overflow
12 stream without having to make a spiral journey down the first cyclone
cavity.
13 The portion of the bitumen in the first underflow stream may exit the at
least one of the
14 first plurality of cyclones through the first overflow outlet after one
and one half
revolutions.
16 The first inlet channel may be shaped such that a diameter of the first
involute path of the
17 first inlet channel narrows along the first involute path as the first
inlet channel
18 approaches a central location proximate the first vortex finder.
19 The system may further comprise a reflection of a first descending helix
vortex fluid flow
into a first ascending helix vortex fluid flow forms in a central zone near
the first lower
21 apex outlet of the first cyclone cavity.
22 The system may further comprise a first central vapour core extending
along an axis of
23 the first cyclone body.
24 The first central vapour core may be only millimeters in diameter and is
sized sufficiently
to cause about 3% to about 4% enrichment in a solvent to bitumen ratio of the
second
26 overflow stream.
7f
CA 02787798 2013-05-13
1 In a
further aspect of the present invention there is provided a method for
processing a
2
bitumen feed comprising a mixture of bitumen, water and mineral. The method
may
3 comprise:
4
separating bitumen from the bitumen feed with a first inclined plate separator
to
produce a first overflow stream and a first underflow stream, the first
6
overflow stream comprising a first bitumen enriched stream and the first
7 underflow stream comprising a first bitumen reduced stream;
8
separating bitumen from the first underflow stream with a first plurality of
9
cyclones to produce a second overflow stream and a second underflow
stream, the second overflow stream comprising a second bitumen enriched
11 stream
and the second underflow stream comprising a second bitumen
12 reduced stream, wherein each of the first plurality of cyclones
comprises:
13 a
first cyclone body having a first elongated conical inner surface defining
14 a
first cyclone cavity extending from a first upper inlet region with
a first diameter DC1 to a first lower apex outlet with a first
16
diameter DUI, wherein the first diameter DC1 is not less than about
17 150mm
and not more than about 200mm and the first diameter
18 DUI is not less than about 40mm and not more than about
50mm;
19 a
first inlet forming a first inlet channel with a first diameter DI1 extending
into the first upper inlet region of the first cyclone cavity, wherein
21 the
first inlet channel forms a first involute path into the first
22
cyclone cavity and the first diameter Dl1 is approximately 50 mm
23 or less; and
24 a first vortex finder forming a first overflow outlet of a first
diameter DO
extending into the first upper inlet region of the first cyclone cavity
26 toward
the first lower apex outlet and having a first lower end
27
extending a first excursion distance below the first inlet channel,
28
wherein the first lower end of the first vortex finder within the first
7g
CA 02787798 2013-05-13
1
cyclone cavity is disposed a first free vortex height (FV.Fli)
2
distance from the first lower apex outlet and wherein the first
3
diameter DOI is approximately 50mm or less and the first FV1-11
4
distance is not less than about 1133mm and not more than about
1821mm;
6
separating bitumen from the second underflow stream with a second plurality of
7
cyclones to produce a third overflow stream and a third underflow stream,
8 the
third overflow stream comprising a third bitumen enriched stream and
9 the third underflow stream comprising a third bitumen reduced
stream;
modulating a composition of at least a first portion of the second overflow
stream
11 and the third overflow stream to form a first recycle stream; and
12
recycling the first recycle stream to the first inclined plate separator for
further
13 processing.
14 The
method may further comprise separating bitumen from at least a second portion
of
the second overflow stream with a fourth separator to produce a fourth
overflow stream
16 and a
fourth underflow stream, the fourth overflow stream comprising a fourth
bitumen
17
enriched stream and the fourth underflow stream comprising a fourth bitumen
reduced
18 stream.
19 The fourth separator may comprise a second inclined plate separator.
The fourth separator may comprise a first centrifuge for processing the second
portion of
21 the second overflow stream.
22 The
method may further comprise diverting the second overflow stream between the
first
23 recycle stream and the fourth separator.
24 The
method may further comprise separating bitumen from at least a third portion
of the
second overflow stream with a fifth separator to produce a fifth overflow
stream and a
26 fifth
underflow stream, the fifth overflow stream comprising a fifth bitumen
enriched
27 stream and the fifth underflow stream comprising a fifth bitumen reduced
stream.
7h
CA 02787798 2013-05-13
I The fifth separator may comprise a second centrifuge for processing the
third portion of
2 the second overflow stream.
3 The method may further comprise diverting the second overflow stream
among the first
4 recycle stream, the fourth separator and the fifth separator.
The method may further comprise modulating a composition of the second
underflow
6 stream and the fourth underflow stream to form a first combined stream
for processing by
7 the third separation stage.
8 The method may further comprise modulating a composition of the first
recycle stream
9 and the bitumen feed to form a second combined stream for processing by
the first
inclined plate separator.
11 The first overflow stream may comprise a first diluted bitumen product
stream.
12 The fourth overflow stream may comprise a second diluted bitumen product
stream.
13 The fifth overflow stream may comprise a third diluted bitumen product
stream.
14 The third underflow stream may form a first tailings stream.
The fifth underflow stream may form a second tailings stream.
16 The third bitumen reduced stream may have less bitumen than the first
bitumen reduced
17 stream.
18 The third bitumen reduced stream may have less bitumen that the second
bitumen
19 reduced stream.
The third bitumen reduced stream may have less bitumen that the fourth bitumen
reduced
21 stream.
22 The first bitumen reduced stream may have more bitumen than the second
bitumen
23 reduced stream.
7i
CA 02787798 2013-05-13
I The first bitumen reduced stream may have more bitumen than the fourth
bitumen
2 reduced stream.
3 The method may further comprise diluting the bitumen feed with a solvent.
4 The solvent may comprise a paraffinic solvent.
The solvent may comprise naphtha.
6 The first diluted bitumen product stream may comprise approximately 34% or
more
7 solvent by weight.
8 The first diluted bitumen product stream may comprise approximately 2.1%
or less water
9 by weight.
The first diluted bitumen product stream may comprise approximately 97% or
more
11 hydrocarbon by weight.
12 The first diluted bitumen product stream may comprise approximately 1.2%
or less solids
13 by weight.
14 The first and second diluted bitumen product streams in combination may
comprise
approximately 34% or more solvent by weight, approximately 2.1% or less water
by
16 weight, approximately 97% or more hydrocarbon by weight and
approximately 1.2% or
17 less solids by weight.
18 The first, second and third diluted bitumen product streams in
combination may comprise
19 approximately 34% or more solvent by weight, approximately 2.1% or less
water by
weight, approximately 97% or more hydrocarbon by weight and approximately 1.2%
or
21 less solids by weight.
22 The bitumen feed may comprise a hybrid emulsion phase comprising a
mélange of water-
23 continuous and oil-continuous emulsions.
24 The first underflow stream may comprise a water-continuous emulsion.
7j
CA 02787798 2013-05-13
1 The
bitumen feed may comprise a bitumen froth formed by an oil sands extraction
2 process.
3 In a
further aspect of the method, each of the second plurality of cyclones used to
4 separate bitumen from the second underflow stream may comprise:
a second cyclone body having a second elongated conical inner surface defining
a
6 second
cyclone cavity extending from a second upper inlet region with a
7 second
diameter DC2 to a second lower apex outlet with a second diameter
8 DU2,
wherein the second diameter DC2 is not less than about 150mm and
9 not
more than about 200mm and the second diameter DU2 is not less than
about 40mm and not more than about 50mm;
11 a
second inlet forming a second inlet channel with a second diameter DI2
12
extending into the second upper inlet region of the second cyclone cavity,
13
wherein the second inlet channel forms a second involute path into the
14 second
cyclone cavity and the second diameter DI2 is approximately 50
mm or less; and
16 a
second vortex finder forming a second overflow outlet of a second diameter
17 DO2
extending into the second upper inlet region of the second cyclone
18 cavity
toward the second lower apex outlet and having a second lower end
19
extending a second excursion distance below the second inlet channel,
wherein the second lower end of the second vortex finder within the
21 second
cyclone cavity is disposed a second free vortex height (FVFI-))
22
distance from the second lower apex outlet and wherein the second
23
diameter DO2 is approximately 50mm or less and the second 17VH2
24
distance is not less than about 1133mm and not more than about 1821mm.
The method may further comprise causing a portion of the bitumen in the second
26
underflow stream that passes through the second inlet channel of at least one
of the
27 second
plurality of cyclones to exit the at least one of the second plurality of
cyclones as
7k
CA 02787798 2013-05-13
I part of the third overflow stream without having to make a spiral journey
down the
2 second cyclone cavity.
3 The method may further comprise causing the portion of the bitumen in the
second
4 underflow stream to exit the at least one of the second plurality of
cyclones through the
second overflow outlet after one and one half revolutions.
6 The second inlet channel may be shaped such that a diameter of the second
involute path
7 of the second inlet channel narrows along the second involute path as the
second inlet
8 channel approaches a central location proximate the second vortex finder.
9 The method may further comprise causing a reflection of a second
descending helix
vortex fluid flow into a second ascending helix vortex fluid flow to form in a
central zone
11 near the second lower apex outlet of the second cyclone cavity.
12 The method may further comprise a second central vapour core extending
along an axis
13 of the second cyclone body.
14 The second central vapour core may be only millimeters in diameter and
is sized
sufficiently to cause about 3% to about 4% enrichment in a solvent to bitumen
ratio of the
16 third overflow stream.
17 The method may further comprise causing a portion of the bitumen in the
first underflow
18 stream that passes through the first inlet channel of at least one of
the first plurality of
19 cyclones to exit the at least one of the first plurality of cyclones as
part of the second
overflow stream without having to make a spiral journey down the first cyclone
cavity.
21 The method may further comprise causing the portion of the bitumen in
the first
22 underflow stream to exit the at least one of the first plurality of
cyclones through the first
23 overflow outlet after one and one half revolutions.
24 The first inlet channel may be shaped such that a diameter of the first
involute path of the
first inlet channel narrows along the first involute path as the first inlet
channel
26 approaches a central location proximate the first vortex finder.
71
CA 02787798 2013-05-13
1 The
method may further comprise causing a reflection of a first descending helix
vortex
2 fluid
flow into a first ascending helix vortex fluid flow to form in a central zone
near the
3 first lower apex outlet of the first cyclone cavity.
4 The
method may further comprise a first central vapour core extendingalong an axis
of
the first cyclone body.
6 The
first central vapour core may be only millimeters in diameter and is sized
sufficiently
7 to
cause about 3% to about 4% enrichment in a solvent to bitumen ratio of the
second
8 overflow stream.
9 In a
further aspect of the present invention, there is provided system for
processing a
bitumen feed comprising bitumen, water and mineral. The system may comprise:
11 a
first separation stage comprising an inclined plate separator configured to
receive
12 the
bitumen feed and separate bitumen from the bitumen feed to produce a
13 first bitumen enriched stream and a first bitumen reduced stream;
14 a
second separation stage comprising a first plurality of cyclones configured to
receive the first bitumen reduced stream from the inclined plate separator and
16 to
separate bitumen from the first bitumen reduced stream to produce a second
17 bitumen enriched stream and a second bitumen reduced stream;
18 a
third separation stage configured to separate bitumen from the second bitumen
19
enriched stream to produce a third bitumen enriched stream and a third
bitumen reduced stream; and
21 a
diverter configured to optionally direct the second bitumen enriched stream to
the
22 first
separation stage for further processing by the first inclined plate separator
23 or to the third separation stage.
24
The system may further comprise a fourth separation stage configured to
separate
26
bitumen from the second bitumen enriched stream to produce a fourth bitumen
27 enriched stream and a fourth bitumen reduced stream.
28
7m
CA 02787798 2013-05-13
The method may further comprise separating bitumen from the second bitumen
2 enriched stream at a fourth separation stage to produce a fourth bitumen
enriched
3 stream and a fourth bitumen reduced stream.
4
The method may further comprise separating bitumen from the second bitumen
6 reduced stream at a fifth separation stage to produce a fifth bitumen
enriched stream
7 and a fifth bitumen reduced stream.
8
9 The third separation stage may comprise a centrifuge configured to
produce the third
bitumen enriched stream and the third bitumen reduced stream.
11
12 The third separation stage may comprise a second inclined plate
separator configured
13 to produce the third bitumen enriched stream and the third bitumen
reduced stream.
14
The fourth separation stage may comprise a centrifuge configured to produce
the third
16 bitumen enriched stream and the third bitumen reduced stream.
17
18 The method may further comprise optionally diverting the second bitumen
enriched
19 stream to the fourth separation stage.
7o
CA 02787798 2012-08-17
I Other aspects and features of the present invention will become apparent
to those ordinarily
2 skilled in the art upon review of the following description of specific
embodiments of the
3 invention in conjunction with the accompanying figures.
4 Brief description of the Drawings
Figure 1 is a schematic diagram depicting a preferred arrangement of apparatus
adapted to carry
6 out the process of the invention.
7 Figure 2 is an elevation cross-section view of a preferred embodiment of
a cyclone.
8 Figure 3 is a top cross-section view of the cyclone of Figure 2.
9 Figure 3a is an enlarged cross-section view of a portion of an operating
cyclone.
Figure 4 is a schematic diagram depicting another preferred arrangement of
apparatus adapted to
11 carry out the process of the invention.
12 Detailed Description of the Invention
13 Figure 1 is a schematic diagram depicting the arrangement of apparatus
adapted to carry out the
14 process of the invention. The schematic diagram provides an outline of
the equipment and the
process flows, but does not include details, such as pumps, that provide the
ability to transport
16 the process fluids from one unit to the next. The apparatus of the
invention includes inclined
17 plate separator (IPS) stage units and cyclone stage units, each of which
process an input stream
18 to produce an overflow output stream, and an underflow output stream.
The IPS overflow output
19 stream has a bitumen enriched content resulting from a corresponding
decrease in solids, fines
and water content relative to the bitumen content of the EPS input stream. The
IPS underflow
21 output stream has solids, fines and water with a depleted bitumen
content relative to the IPS
22 input stream. The IPS underflow output stream may be referred to as a
bitumen depleted stream.
23 The cyclone stage overflow output stream has a bitumen enriched content
resulting from a
24 corresponding decrease in solids, fines and water content relative to
the bitumen content of the
cyclone input stream. The cyclone underflow output stream has solids, fines
and water with a
26 depleted bitumen content relative to the cyclone input stream. The
cyclone underflovv output
27 stream may be referred to as a bitumen depleted stream.
214763E3.1 8
CA 02787798 2012-08-17
=
1 While the process flows and apparatus description of the invention made
with reference to Figure
2 1 refers to singular units, such as a cyclone 16 or 28, a plurality of
cyclone units are used in each
3 stage where process scale requires. For example, for production rates in
excess of 200,000
4 bbl/day of bitumen, cyclone units are arranged in parallel groups of 30
or more with each
cyclone unit bearing about 200 gal/rain of flow. In the general arrangement of
the apparatus
6 adapted to carry out the process, inclined plate separator (IPS) units
are alternately staged with
7 cyclone units such that an IPS stage underflow feeds a cyclone stage,
while a cyclone stage
8 overflow feeds an IPS stage. The mutual conditioning of each stage
contributes to the
9 remarkable constituent separation performance obtained by the unit
staging of this process.
The processing circuit has a circuit inlet 10 to receive a process feed stream
48. The process
11 feed stream is a bitumen froth output of an oil sands extraction process
and is diluted at 11 with a
12 suitable solvent, for example naphtha, or a paraffinic or alkane
hydrocarbon solvent. Naphtha is
13 a mixture of aromatic hydrocarbons that effectively dissolves the
bitumen constituent of the
14 bitumen froth feed stream 48 supplied via line 10 to produce bitumen
froth with a much-reduced
viscosity. The addition of a solvent partially liberates the bitumen from the
other components of
16 the bitumen froth feed stream 48 by reducing interfacial tensions and
rendering the composition
17 more or less miscible. The diluted bitumen feed stream 50 including a
recycle stream 57 is
18 supplied to a primary IPS stage comprising IPS units 12 and 14 shown as
an example of multiple
19 units in a process stage. The overflow output stream 52 of the primary
IPS stage is supplied as a
product stream, which is sent to the circuit product outlet line 42 for
downstream processing, for
21 example at an up grader plant.
22 The underflow output stream of the primary IPS stage is supplied via
line 30 as the feed stream
23 68 to a primary hydrocarbon cyclone stage (HCS) comprising for example,
a primary cyclone 16.
24 The hydrocarbon cyclone processes a feed stream into a bitumen enriched
overflow stream and a
bitumen depleted underflow stream. The overflow output stream 56 of the
primary cyclone stage
26 on line 18 is directed for further processing depending on the setting
of diverter valve 34.
27 Diverter valve 34 is adjustable to direct all or a portion of the
primary HCS overflow output
28 stream 56 to a recycle stream 60 that is carried on line 24 to become
recycle stream 57 or a part
29 of it. Recycle stream 57 is supplied to the primary IPS stage. The
portion of the primary HCS
overflow output stream that is not directed to recycle stream 60 becomes the
secondary EPS feed
21476383.1 9
CA 02787798 2012-08-17
1 stream 58 that is delivered to a secondary IPS stage 22 via line 20.
Naturally diverter valve 34
2 can be set to divert the entire HCS overflow stream 56 to the secondary
PS feed stream 58 to the
3 limit of the secondary IPS capacity.
4 The circuit bitumen froth feed stream 48 will have varying quantities or
ratios of constituent
components of bitumen, solids, fmes and water. The quantities or ratios of the
component of
6 froth feed stream 48 will vary over the course of operation of the
circuit depending on the
7 composition of the in situ oil sands ore that are from time to time being
mined and processed.
8 Adjustment of diversion valve 34 permits the processing circuit flows to
be adjusted to
9 accommodate variations in oil sands ore composition, which is reflected
in the composition of
the bitumen froth feed stream 48. In this manner, the circuit process feed
flow 50 to the primary
11 cyclone stage can be set to adapt to the processing requirements
providing optimal processing for
12 the composition of the bitumen froth feed. In some circumstances, such
as when the capacity of
13 the secondary IPS stage 22 is exceeded, all or a portion of the primary
cyclone stage overflow
14 stream 56 on line 18 is directed to recycle stream 60 by diverter valve
34. Recycle stream 60 is
carried on line 24 to form part of the recycle stream 57 supplied to the
primary IPS stage IPS
16 units 12 and 14. However, the composition of stream 48 is nearly
invariant to the composition of
17 mine run ore over a wide range of ores that might be fed to the upstream
extraction process.
18 The preferred embodiment of a process circuit in accordance with the
principles of the invention
19 preferably includes secondary IPS processing equipment interconnecting
with the primary
processing equipment by means of diverter valve 34. Where the entire overflow
output stream of
21 the primary stage is recycled back to the prinary EPS stage, the primary
IPS stage process acts as
22 a secondary 1PS stage and no stream is supplied to the secondary IPS
stage for processing.
23 However, a secondary PS stage is preferably provided to accommodate the
variations in
24 composition of the feed froth stream 48 encountered in operation of the
process. Secondary PS
unit 22 processes the feed stream 58 received from the overflow of the primary
cyclone stage
26 into a bitumen enriched secondary IPS overflow output stream on line 32
and a bitumen depleted
27 secondary IPS underflow output stream 59 on line 26. The recovered
bitumen of the secondary
28 IPS overflow stream on line 32 is combined with the overflow stream of
the primary PPS stage to
29 provide the circuit output bitumen product stream 52 delivered to the
circuit product outlet line
42 for downstream processing and upgrading.
214763E3 10
CA 02787798 2012-08-17
1 The secondary stage PS 22 underflow output stream 59 is supplied by
line 26 where it is
2 combined with the primary cyclone underflow stream 61 to provide a
feed stream 62 to a
3 secondary stage cyclone 28. The secondary hydrocarbon cyclone stage
(HCS) 28 processes
4 input feed stream 62 into a bitumen enriched secondary HCS overflow
output stream 64 on line
40 and a bitumen depleted secondary HCS underflow output stream 66 on line 36.
The
6 secondary HCS underflow output stream 66 is directed to a solvent
recovery unit 44, which
7 processes the stream to produce the circuit tailings stream 54
provided to the circuit tails outlet
8 46 of the circuit. The operating process of the secondary HCS 28 is
varied during the operation
9 of the process. The operating process of the secondary HCS 28 is
optimized to reduce the
bitumen content of the secondary HCS underflow output stream 66 to achieve the
target bitumen
11 recovery rate of the process. Preferably, the operation of the
secondary HCS is maintained to
12 achieve a hydrocarbon content in the secondary HCS underflow output
stream 66 that does not
13 exceed 1.6%. Preferably, a solvent recovery unit 44 is provided to
recover diluent present in the
14 secondary HCS underflow output stream 66. Solvent recovery unit
(SRI.T) 44 is operated to
maintain solvent loss to the tailings stream 54 below 0.5% to 0.7% of the
total solvent fed to the
16 circuit on line 11. The tailings stream 54 is sent for disposal on
the circuit tails outlet line 46.
17 The primary and secondary HCS cyclone units achieve a so-called
ternary split in which a high
18 hydrocarbon recovery to the output overflow stream is obtained with a
high rejection of solids
19 and water reporting to the output underflow stream. In a ternary
split, even the fines of the solids
are rejected to a respectable extent.
21 The primary HCS cyclone unit 16 receives the underflow output stream
on line 30 from the
22 primary IPS stage IPS units 12, 14 as an input feed stream 68. The
primary hydrocarbon cyclone
23 16 processes feed stream 68 to obtain what is referred to herein as
a ternary split. The
= 24 hydrocarbon and other constituents of the cyclone feed stream
are reconstituted by the
hydrocarbon cyclone 16 so as to enable the primary HCS overflow output stream
on line 18 to be
26 supplied, via line 20, as a feed stream 58 to a secondary TIPS stage
unit 22. This process flow
27 obtains a ternary split, which achieves a high bitumen recovery. The
process within primary
28 HCS cyclone unit 16 involves a complex transformation or re-
conditioning of the received
29 primary TIPS undernow output stream 68. The primary HCS underflow
output stream 61 is
passed via line 38 to become part of the feed stream 62 of secondary HCS
cyclone unit 28 and
2147633.I 11
CA 02787798 2012-08-17
1 yield further bitumen recovery. Further bitumen recovery from the
secondary HCS overflow
2 output stream 64 is obtained by recycling that stream on line 40 back to
the primary IPS stage for
3 processing.
4 The closed loop nature of the recycling of this process reveals an inner
recycling loop, which is
closed through line 26 from the secondary IPS stage and an outer recycling
loop, which is closed
6 through line 40 from the secondary HCS. These recycle loops provide a
recycle stream 57 which
7 contains material from the primary and secondary HCS and the bitumen
recovered from this
8 recycle material is called second-pass bitumen. Remarkably the second-
pass bitumen in recycle
9 stream 57 is recovered in the primary IPS stage at greater than 90% even
though the bitumen did
not go to product in the first pass through the primary IPS stage. Thus, the
arrangement provides
11 a cyclic process in which the overflow stream of a HCS is reconditioned
by an IPS stage and the
12 underflow stream of an IPS stage is reconditioned by a HCS. In this way,
the individual process
13 stages recondition their overflow streams in the case of cyclone stages
and their underflow
14 streams in the case of IPS stages for optimal processing by other
downstream stages in the
process loops. In the HCS cyclone units, the flow rates and pressure drops can
be varied during
16 operation of the circuit. The HCS unit flow rates and pressure drops are
maintained at a level to
17 achieve the performance stated in Tables 1 and 2. An input stream of a
cyclone is split to the
18 overflow output stream and the underflow output stream and the operating
flow rates and
19 pressure drops will determine the split of the input stream to the
output streams. Generally, the
range of output overflow split will vary between about 50% to about 80% of the
input stream by
21 varying the operating flow rates and pressure drops.
22 Table 1 provides example compositions of various process streams in the
closed-loop operation
23 of the circuit.
Table 1
Bitume Minera Coars Hydrocarbo
Stream Water Solvent Fines
1
48 New 55.00 8.50 36.50 00.00 3.38 5.12 55.00
feed
21476353.1 12
CA 02787798 2012-08-17
50 EPS feed 34.95 5.95 41.57 17.52 2.17 3.78 52.48
52 Product 63.51 0.57 2.06 33.86 0.00 0.57 97.37
54 Tails 1.02 17.59 80.98 0.59 7.42 10.17 1.61
1
2 Table 2 lists process measurements taken during performance of process
units arranged in
3 accordance with the invention. In the table, the Bitumen column is a
hydrocarbon with zero
4 solvent. Accordingly, the Hydrocarbon column is the sum of both the
Bitumen and Solvent
columns. The Mineral column is the sum of the Coarse and the Fines columns.
These data are
6 taken from a coherent mass balance of operational data collected during
demonstration and
7 operational trials. From these trials it was noted that water rejection
on the HCS is over 50%. It
8 was also noted that the nominal recovery of IPS stage is about 78%, but
was boosted to over
9 85% by the recycle. All of the stages in the circuit operate in
combination to produce a recovery
of bitumen approaching 99% and the solvent losses to tails are of the order of
0.3%.
Table 2
Unit Operations Performance of Hydrocarbon Cyclones and Inclined Plate
Separators in
Closed Loop
Unit Process Unit Unit Water Unit Solids Fines
Rejection
Hydrocarbon Rejection Rejection
Recovery
Primary IFS 78% 98% 97%
Primary 85% 55% 78%
Cyclone
Secondary 85% 54% 82%
Cyclone
Recycle or 91% 98.5% 95.5%
Secondary IFS
Overall 99.2% Bitumen
, Recovery 99.7% Solvent
21476383,1 13
CA 02787798 2012-08-17
Product Spec 2.0% H20 0.57%
Mineral
0.32% non-
bituminous
hydrocarbon
(NBHC)
1
2 Figure 2 shows an elevation cross-section of a preferred embodiment of
the hydrocarbon cyclone
3 apparatus depicting the internal configuration of the cyclone units. The
cyclone 70 defines an
4 elongated conical inner surface 72 extending from an upper inlet region
74 to an outlet
underflow outlet 76 of lower apex 88. The cyclone has an upper inlet region 74
with an inner
6 diameter DC and an upper overflow outlet 84 of a diameter DO at the
vortex finder 82 and an
7 underflow outlet 76 at the lower apex, which has a diameter DU. The
effective underflow outlet
8 diameter 76 at the lower apex 88 of the cyclone is also referred to as a
vena cava. It is somewhat
9 less than the apex diameter due to the formation of an up-vortex having a
fluid diameter called
the vena cava. The fluid flows near the lower apex 88 of a cyclone are shown
in Figure 3a. The
11 cyclone has a free vortex height FVH extending from the lower end 92 of
the vortex finder to the
12 vena cava of the lower apex 88. The fluid to be treated is supplied to
the cyclone via input
13 channel 78 that has an initial input diameter DI. The input channel 78
does not need to have a
14 uniform cross-section along its entire length from the input coupling to
the cyclone inlet 80. The
fluid to be treated is supplied under pressure to obtain a target velocity
within the cyclone when
16 the fluid enters the cyclone through cyclone inlet SO. Force of gravity
and the velocity pressure
17 of the vortex urge the fluid composition entering the cyclone inlet
downward toward apex 76.
18 An underflow fluid stream is expelled through the lower apex 76. The
underflow stream output
19 from the cyclone follows a generally helical descent through the cyclone
cavity. The rate of
supply of the fluid to be treated to the cyclone 70 causes the fluid to rotate
counter-clockwise (in
21 the northern hemisphere) within the cyclone as it progresses from the
upper inlet region 74
22 toward the underflow exit of lower apex '76. Variations in density of
the constituent components
23 of the fluid composition cause the lighter component materials,
primarily the bitumen
24 component, to be directed toward vortex finder 82 in the direction of
arrow 86.
21476383.1 14
CA 02787798 2012-08-17
1 As depicted in Figure 3a, when the cyclone is operating properly the
fluid exits the apex of they
2 cyclone as a forced spray 89 with a central vapour core 97 =tending along
the axis of the
3 cyclone. Near the apex 76 a central zone subtended by the vena cava 91 is
formed. The vena
4 cava is the point of reflection or transformation of the descending helix
93 into an ascending
helix 95. Contained within this hydraulic structure will be an air core or
vapour core 97
6 supported by the helical up and down vortices. This structure is stable
above certain operating
7 conditions, below which the flow is said to rope. Under roping conditions
the air core and the
8 up-vortex will collapse into a tube of fluid that will exit downward with
a twisting motion.
9 Under these circumstances the vortex flow will cut off and there will be
zero separation. Roping
occurs when the solids content of the undertow slurry becomes intolerably
high.
11 The vortex finder 82 has a shortened excursion where the vortex finder
lower end 92 extends
12 only a small distance below cyclone inlet 80. A shortened vortex finder
allows a portion of the
13 bitumen in the inlet strewn to exit to the overflow output passage 84
without having to make a
14 spiral journey down into the cyclone chamber 98 and back up to exit to
the overflow output
passage 84. However, some bitumen in the fluid introduced into the cyclone for
processing does
16 make this entire journey through the cyclone chamber to exit to the
overflow output passage 84.
17 The free vortex height FVH, measured from the lower end of the vortex
finder 92 to the
18 undertow outlet 76 of lower apex 88, is long relative to the cyclone
diameters DI and DO.
19 Preferably, a mounting plate 94 is provided to mount the cyclone, for
example, to a frame
structure (not shown).
21 Preferably the lower portion 88 of the cyclone is removably affixed to
the body of the cyclone by
22 suitable fasteners 90, such as bolts, to permit the lower portion 88 of
the cyclone to be replaced.
23 Fluid velocities obtained in operation of the cyclone, cause mineral
materials that are entrained
24 in the fluid directed toward the lower apex undertow outlet 76 to be
abrasive. A removable
lower apex 88 portion permits a high-wear portion of the cyclone to be
replaced as needed for
26 operation of the cyclones. The assembly or packaging of the so-called
cyclopac has been
27 designed to facilitate on-line replacement of individual apex units for
maintenance and insertion
28 of new abrasion resistant liners.
21476383.1 15
CA 02787798 2012-08-17
1 Figure 3 shows a top view cross-section of the cyclone of Figure 2. The
cyclone has an
2 injection path 96 that extends from the input channel 78 to the cyclone
inlet 80. Various
3 geometries of injection path can be used, including a path following a
straight line or a path
4 following a curved line. A path following a straight line having an
opening into the body of the
cyclone that is tangential to the cyclone is called a Lupul Ross cyclone. In
the preferred
6 embodiment, the injection path 96 follows a curved line that has an
involute geometry. An
7 involute injection path assists in directing the fluid supplied to the
cyclone to begin to move in a
8 circular direction in preparation for delivery of the fluid through
cyclone inlet 80 into the
9 chamber 98 of the cyclone for processing. The counter-clockwise design is
for use in the
northern hemisphere in order to be in synch with the westerly coriolis force.
In the southern
11 hemisphere this direction would be reversed.
12 In the preferred embodiment of the cyclone, the dimensions listed in
Table 3 are found:
13 TABLE 3
Path DI DC DO DU FVH ABRV
Primary Involute 50131M 200mm 50mm 40mm 1821mm 102mm
Cyclone
Secondary Involute 50mm 150mm 50mm 50mm 1133mm 105mm
Cyclone
Lupul Ross Tangent 9.25ram 64mm 19mm 6.4mm 181mm 32nam
Cyclone
14
Where:
16 Path is the injection path length geometry. If the path is an
involute, the body diameter DC
17 is a parameter of the involute equation that defines the path of
entry into the cyclone
18 DI is the inlet diameter at the entry of the fluid flow to the
cyclone
19 DC is the body diameter of the cyclone in the region of entry into
the cyclone
DO is the overflow exit path vortex finder diameter or the outlet pipe
diameter
21 DU is the underflow exit path apex diameter at the bottom of the
cyclone, also called the
22 vena cava
214763S3.1 16
CA 02787798 2012-08-17
1 FVH is the free vortex height or the distance from the lower end
of the vortex finder to the
2 vena cava
3 ABRV is the distance from the centre-line of the inlet flow path
to the tip of the vortex
4 Ender. The shorter this distance the more abbreviated is the vortex
finder.
6 The cyclones are dimensioned to obtain sufficient vorticity in the down
vortex so as to cause a
7 vapor core 97 in the centre of the up-vortex subtended by the vena cava.
The effect of this vapor
8 core is to drive the solvent preferentially to the product stream,
provided to the overflow output
9 port 84, thereby assuring minimum solvent deportment to tails or under-
flow stream, provided to
the underflow outlet 76 of lower apex. This is a factor contributing to higher
solvent recovery in
11 the process circuit. At nominal solvent ratios the vapor core is
typically only millimeters in
12 diameter, but this is sufficient to cause 3% to 4% enrichment in the
overhead solvent to bitumen
13 ratio.
14 A workable cyclone for use in processing a diluted bitumen froth
composition has a minimum an
apex diameter of 40mm to avoid plugging or an intolerably high fluid
vorticity. An apex
16 diameter below 40mm would result in high fluid tangential velocity
yielding poor life
17 expectancy of the apex due to abrasion even with the most abrasion
resistant material.
18 Consequently, a Lupul Ross cyclone design is undesirable because of the
small size of openings
19 employed.
The embodiments of the primary and secondary cyclones of the dimensions stated
in Table 3
21 sustain a small vapour core at flow rates of 180 gallon/min or more.
This causes enrichment in
22 the solvent content of the overflow that is beneficial to obtaining a
high solvent recovery. The
23 vapour core also balances the pressure drops between the two exit paths
of the cyclone. The long
24 body length of these cyclones fosters this air core formation and
assists by delivering high
gravity forces within the device in a manner not unlike that found in
centrifuges, but without the
26 moving parts. In the preferred embodiment of the primary cyclone, the
upper inlet region has an
27 inner diameter of 200 mm. The injection path is an involute of a circle,
as shown in Figure 3. In.
28 one and one half revolutions prompt bitumen can move into the vortex
finder and exit to the
29 overflow output passage 84 if the solvent to bitumen ratio is properly
adjusted. The internal
dimensions of the secondary cyclones are similar and the same principles apply
as were stated in
21476383.1 17
CA 02787798 2012-08-17
1 relation to the primary cyclones. However, the diameter of the body of
the secondary cyclone is
2 150 mm to create a higher centrifugal force and a more prominent vapour
core. The dimensions
3 of the secondary cyclone are aimed at producing minimum hydrocarbon loss
to tails. This is
4 accomplished with as low as 15% hydrocarbon loss, which still allows for
a water rejection
greater than 50%.
6 The IPS units 12,14 and 22 of the IPS stages are available from
manufacturers such as the Model
7 SRC slant rib coalescing oil water separator line of IPS equipment
manufactured by Parkson
8 Industrial Equipment Company of Florida, U.S.A..
9 Figure 4 is a schematic diagram depicting another preferred arrangement
of apparatus adapted to
carry out the process of the invention. As with Figure 1, the schematic
diagram provides an
11 outline of the equipment and the process flows, but does not include
details, such as pumps that
12 provide the ability to transport the process fluids from one unit to the
next. The apparatus of the
13 invention includes inclined plate separator (LPS) stage units and
cyclone stage units and
14 centrifuge stage units, each of which process an input stream to produce
an overflow output
stream, and an underflow output stream The centrifuge overflow output stream
has a bitumen
16 enriched content resulting from a corresponding decrease in solids,
fines and water content
17 relative to the bitumen content of the centrifuge input stream. The
centrifuge underflow output
18 stream has solids, fines and water with a depleted bitumen content
relative to the centrifuge input
19 stream. The centrifuge underflow output stream may be referred to as a
bitumen depleted
stream.
21 In the general arrangement of the apparatus adapted to carry out the
process, inclined plate
22 separator (IPS) units are alternately staged with either cyclone units
or centrifuge units such that
23 an IPS stage undefflow feeds a cyclone stage or a centrifuge stage or
both a cyclone stage and a
24 centrifuge stage. In addition a cyclone stage overflow or a centrifuge
stage overflow is sent to
product or feeds an IPS stage. This circuit enables one to take full advantage
of centrifuges that
26 might be destined for replacement. In another sense it provides a
fallback to the circuit depicted
27 in Figure 1.
28 In Figure 4, the same reference numerals are used to depict like
features of the invention. The
29 processing circuit has a circuit inlet 10 to receive a process feed
stream 48. The process feed
2147633.1 18
CA 02787798 2012-08-17
=
1 stream is a deaerated bitumen froth output of an oil sands extraction
process and is diluted at 11
2 with a suitable solvent, for example naphtha, or a paraffinic or alka.ne
hydrocarbon solvent. The
3 diluted bitumen feed stream 50 including a recycle streams 60 and 64 is
supplied to a primary
4 IPS stage comprising IPS units 12 and 14 shown as an example of multiple
units in a process
stage. The overflow output stream 52 of the primary TIPS stage is supplied as
a product stream,
6 which is sent to the circuit product outlet line 42 for downstream
processing, for example at an
7 upgrader plant.
8 The underflow output stream of the primary US stage is supplied via line
30 as the feed stream
9 68 to a primary hydrocarbon cyclone stage (HCS) comprising for example, a
primary cyclone 16.
The hydrocarbon cyclone processes a feed stream into a bitumen enriched
overflow stream and a
11 bitumen depleted underflow stream. The overflow output stream 56 of the
primary cyclone stage
12 on line 18 is directed for further processing depending on the setting
of diverter valve 34.
13 Diverter valve 34 is adjustable to direct all or a portion of the
primary HCS overflow output
14 stream 56 to a recycle stream 60 that is carried on line 3 to become a
recycle input to the feed
stream 50 supplied to the primary DPS stage. The portion of the primary HCS
overflow output
16 stream that is not directed to recycle stream 60 can become all or a
portion of either the
17 secondary IPS feed stream 58 that is delivered to a secondary IPS stage
22 via line 2 or a
18 centrifuge stage feed stream 100 that is delivered to a centrifuge stage
102 via line 1. Naturally
19 diverter valve 34 can be set to divert all of the HCS overflow stream 56
either to the secondary
IFS feed stream 58 or to the centrifuge stage 102.
21 When paraffinic solvents are deployed asphaltene production will occur.
Under these
22 circumstances the first stage cyclone underflow stream 61 can be
configured separate from the
23 second stage cyclones to provide two separate tailings paths for
asphaltenes. On the other hand,
24 asphaltene production is very low when naphtha based solvents are
deployed in this process and,
consequently, two separate tailings paths are not required.
26 Adjustment of diversion 'Valve 34 permits the processing circuit flows
to be adjusted to
27 accommodate variations in oil sands ore composition, which is reflected
in the composition of
28 the bitumen froth feed stream 48. In this manner, the circuit process
feed flow SO to the primary
29 cyclone stage can be set to adapt to the processing requirements
providing optimal processing for
23476383.1 19
CA 02787798 2012-08-17
1 the composition of the bitumen froth feed. In some circumstances, such as
when the capacity of
2 the secondary TIPS stage 22 and centrifuge stage 102 is exceeded, all or
a portion of the primary
3 cyclone stage overflow stream 56 on line 18 is directed to recycle stream
60 by diverter valve 34.
4 The preferred embodiment of a process circuit in accordance with the
principles of the invention
preferably includes secondary EPS processing equipment or centrifuge
processing equipment
6 interconnecting with the primary stage processing equipment by means of
diverter valve 34.
7 Where the entire overflow output stream of the primary stage is recycled
back to the primary IPS
8 stage, the primary IPS stage process acts as a secondary EPS stage and no
stream is supplied to
9 the secondary IPS stage or the centrifuge stage for processing. However,
a secondary TIPS stage
or centrifuge stage or both is preferably provided to accommodate the
variations in composition
11 of the feed froth stream 48 encountered in operation of the process.
Secondary TIPS unit 22
12 processes the feed stream 58 received from the overflow of the primary
cyclone stage into a
13 bitumen enriched secondary TS overflow output stream on line 32 and a
bitumen depleted
14 secondary EPS underflow output stream 59 on line 26. The recovered
bitumen of the secondary
IPS overflow stream on line 32 is combined with the overflow stream of the
primary TS stage to
16 provide the circuit output bitumen product stream 52 delivered to the
circuit product outlet line
17 42 for downstream processing and upgrading. The centrifuge stage unit
102 processes the feed
18 stream 100 received from the overflow of the primary cyclone stage into
a bitumen enriched
19 centrifuge output stream on line 104 and a bitumen depleted centrifuge
underflow output stream
106 on line 108. The recovered bitumen of the centrifuge overflow stream on
line 104 is
21 supplied to the circuit output bitumen product stream 52, which is
delivered to the circuit product
22 outlet line 42 for downstream processing and upgrading.
23 The secondary stage TS 22 underflow output stream 59 is processed in
this embodiment in the
24 same manner as in the embodiment depicted in Figure 1. The secondary HCS
underflow output
stream and the centrifuge output stream 106 are combined to form stream 66,
which is directed
26 to a solvent recovery unit 44. The solvent recovery unit 44 processes
stream 66 to produce a
27 circuit tailings stream 54 that is provided to the circuit tails outlet
46 of the circuit. The solvent
28 recovery unit (SRU) 44 is operated to maintain solvent loss to the
tailings stream 54 between
29 0.5% to 0.7% of the total solvent fed to the circuit at 11. The tailings
stream 54 is sent for
disposal on the circuit tails outlet line 46.
21476383.1 20
CA 02787798 2012-08-17
1 The closed loop nature of the recycling of this process reveals two
recycling loops. One
2 recycling loop is closed through line 3 from the primary IPS stage and
primary HCS. Another
3 recycling loop is closed from line 2 through the secondary [PS stage via
line 26 and through the
4 secondary HCS 28 via stream 64, The feed to the disk centrifuges on line
1 does not provide a
recycle loop; thus material sent to the disk centrifuge stage is not recycled
back to the primary
6 EPS stage. The HCS unit flow rates and pressure drops are maintained at a
level that achieves the
7 performance stated in Tables 1 and 2. An input stream of a cyclone is
split to the overflow
8 output stream and the underflow output stream and the operating flow
rates and pressure drops
9 will determine the split of the input stream to the output streams.
Generally, the range of output
overflow split will vary between about 50% to about 80% of the input stream by
varying the
11 operating flow rates and pressure drops.
12 Although a preferred and other possible embodiments of the invention
have been described in
13 detail and shown in the accompanying drawings, it is to be understood
that the invention in not
14 limited to these specific embodiments as various changes, modifications
and substitutions may
be made without departing from the spirit, scope and purpose of the invention
as defined in the
16 claims appended hereto.
17
2147633.1 21
