U.S. patent application number 13/460571 was filed with the patent office on 2013-04-25 for process, apparatus and system for treating a hydrocarbon feedstock.
This patent application is currently assigned to SUNCOR ENERGY INC.. The applicant listed for this patent is Thomas Charles Hann. Invention is credited to Thomas Charles Hann.
Application Number | 20130098846 13/460571 |
Document ID | / |
Family ID | 40668810 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130098846 |
Kind Code |
A9 |
Hann; Thomas Charles |
April 25, 2013 |
PROCESS, APPARATUS AND SYSTEM FOR TREATING A HYDROCARBON
FEEDSTOCK
Abstract
An apparatus, process and system for treating a hydrocarbon
feedstock having a specific gravity differential between components
of the feedstock is disclosed and includes a treatment vessel
having an inlet for receiving the feedstock. A primary separation
container may be located in the treatment vessel to accumulate
feedstock to cause a low specific gravity portion of the feedstock
to separate and rise to an upper surface of the accumulated
feedstock. A secondary separation container may be located in the
treatment vessel to receive the collected low specific gravity
portion from the primary separation container, to accumulate the
collected low specific gravity portion to cause hydrocarbon
products to separate and rise to an upper surface of the
accumulated low specific gravity portion of the feedstock,
producing a hydrocarbon product stream at a product outlet. The
operating pressure of the treatment vessel may be regulated to
remain within a desired range.
Inventors: |
Hann; Thomas Charles;
(Onoway, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hann; Thomas Charles |
Onoway |
|
CA |
|
|
Assignee: |
SUNCOR ENERGY INC.
CALGARY
CA
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20120211436 A1 |
August 23, 2012 |
|
|
Family ID: |
40668810 |
Appl. No.: |
13/460571 |
Filed: |
April 30, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12277261 |
Nov 24, 2008 |
8168071 |
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13460571 |
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11938226 |
Nov 9, 2007 |
8225944 |
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12277261 |
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11595817 |
Nov 9, 2006 |
8096425 |
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11938226 |
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Current U.S.
Class: |
210/741 ;
210/137; 210/255; 210/256; 210/800 |
Current CPC
Class: |
C10G 1/00 20130101; C10G
7/00 20130101; C10G 2300/308 20130101; B01D 21/0039 20130101; C10G
1/047 20130101; B01D 21/10 20130101; B01D 2221/04 20130101; C10G
2300/802 20130101; B01D 21/003 20130101; C10G 2300/206 20130101;
B01D 21/0045 20130101; B01D 21/2494 20130101 |
Class at
Publication: |
210/741 ;
210/800; 210/256; 210/137; 210/255 |
International
Class: |
B01D 21/02 20060101
B01D021/02; B01D 21/30 20060101 B01D021/30; B01D 21/24 20060101
B01D021/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2005 |
CA |
2526336 |
Nov 7, 2008 |
CA |
2643472 |
Claims
1. A process for treating a hydrocarbon feedstock having a specific
gravity differential between components of the feedstock to produce
a hydrocarbon product stream, the process comprising: receiving the
feedstock at an inlet of a treatment vessel; accumulating feedstock
in a primary separation container in the treatment vessel, wherein
a low specific gravity portion of the feedstock separates and rises
toward an upper surface of the accumulated feedstock; collecting
the low specific gravity portion from the accumulated feedstock in
the primary separation container; accumulating the low specific
gravity portion in a secondary separation container in the
treatment vessel, wherein hydrocarbon products separate and rise
toward an upper surface of the accumulated low specific gravity
portion; and collecting the hydrocarbon products from the
accumulated low specific gravity portion producing the hydrocarbon
product stream.
2. The process of claim 1 further comprising: in response to an
operating pressure of the treatment vessel rising above a
pre-determined maximum operating pressure, causing at least some
gaseous products produced from the feedstock to be vented out of
the treatment vessel to lower the operating pressure.
3. The process of claim 2 further comprising: in response to the
operating pressure of the treatment vessel falling below a
pre-determined minimum operating pressure, introducing pressurized
gas to the treatment vessel, wherein the operating pressure in the
treatment vessel is raised.
4. The process of claim 1 further comprising directing feedstock to
flow along a downwardly inclined base of the primary separation
container to cause solids in the feedstock to settle to facilitate
discharging the settled solids from a first outlet of the treatment
vessel.
5. The process of claim 4 wherein the downwardly inclined base
forms a dividing wall between the primary separation container and
the secondary separation container.
6. The process of claim 4 wherein at least a portion of the
secondary separation container is located below the downwardly
inclined base of the primary separation container.
7. The process of claim 1 wherein collecting the hydrocarbon
products comprises causing the hydrocarbon products to overflow
over a weir in the secondary separation container into a launder
box in communication with a product outlet of the treatment
vessel.
8. The process of claim 1 further comprising directing flow of
feedstock from the inlet of the treatment vessel to a feed manifold
operably configured to spread out the feedstock flow to reduce
turbulence intensity and to provide a generally uniform feed of
feedstock into the primary separation container.
9. The process of claim 1 further comprising causing a flow rate of
the feedstock to be slowed as it approaches a first weir of the
primary separation container, the first weir being configured to
collect the low specific gravity portion from the accumulated
feedstock in the primary separation container.
10. The process of claim 9 further comprising causing a portion of
the feedstock to overflow at a second weir downstream of the first
weir to produce a second discharge stream comprising predominantly
water and fine solids.
11. The process of claim 1 further comprising: discharging
predominantly coarse solids, precipitated asphaltenes and water
from the primary separation container via a first outlet of the
treatment vessel; and discharging predominantly fine solids and
water from the primary separation container via a second outlet of
the treatment vessel.
12. The process of claim 11 further comprising: discharging
predominantly water from the secondary separation container via a
third outlet of the treatment vessel; and discharging predominantly
hydrocarbon products from the secondary separation container via a
fourth outlet of the treatment vessel.
13. The process of claim 1 further wherein the feedstock comprises
heavy hydrocarbon products, water, solids, and diluent in a
proportion of 60-80% of the feedstock.
14. A process for treating a hydrocarbon feedstock having a
specific gravity differential between components of the feedstock
to produce a hydrocarbon product stream, the process comprising:
receiving the feedstock into a treatment vessel containing first
and second separation containers; collecting a low specific gravity
portion of the feedstock in the first separation container, and
discharging the low specific gravity portion into a secondary
separation container; accumulating the low specific gravity portion
of the feedstock in the secondary separation container, wherein
hydrocarbon products separate and rise toward an upper surface of
the accumulated low specific gravity portion; and discharging the
separated hydrocarbon products to a product outlet of the treatment
vessel, to produce the hydrocarbon product stream at the product
outlet.
15. The process of claim 14 further comprising maintaining an
operating pressure of the treatment vessel generally within a
predetermined range.
16. The process of claim 15 further comprising: in response to the
operating pressure in the treatment vessel rising above a
pre-determined maximum operating pressure, causing at least some
gaseous products produced from the feedstock to be vented out of
the treatment vessel to lower the operating pressure.
17. The process of claim 16 further comprising: in response to the
operating pressure in the treatment vessel falling below a
pre-determined minimum operating pressure, causing pressurized gas
to enter the treatment vessel to raise the operating pressure in
the treatment vessel.
18. The process of claim 14 further comprising vertically stacking
the treatment vessel and a second stage treatment vessel, to treat
the feedstock in stages, and configuring interstage feeding between
the treatment vessel and the second stage treatment vessel to occur
via the force of gravity.
19. The process of claim 14 further comprising receiving the
hydrocarbon product stream from the treatment vessel as an input
feedstock to a second stage treatment vessel operably configured to
cause refined hydrocarbon products to be separated from the input
feedstock and discharged at a product outlet of the second stage
treatment vessel to produce a second stage hydrocarbon product
stream.
20. An apparatus for treating a hydrocarbon feedstock having a
specific gravity differential between components of the feedstock,
the apparatus comprising: a first treatment vessel having a first
feedstock inlet for receiving the feedstock; a primary separation
container in the treatment vessel operably configured to receive
the feedstock from the first feedstock inlet of the treatment
vessel, to collect a low specific gravity portion of the feedstock,
and to discharge the low specific gravity portion into a secondary
separation container; wherein the secondary separation container is
operably configured to accumulate the low specific gravity portion
to cause hydrocarbon products in the low specific gravity portion
to separate and rise toward an upper surface of the accumulated low
specific gravity portion, and to discharge the separated
hydrocarbon products via a first product outlet.
21. The apparatus of claim 20 further comprising a pressure
regulator in communication with the first treatment vessel, wherein
the first treatment vessel comprises a pressure containment
vessel.
22. The apparatus of claim 21 wherein the pressure regulator is
operably configured, in response to the operating pressure in the
first treatment vessel rising above a pre-determined maximum
operating pressure, to cause at least some gaseous products to be
vented out of the treatment vessel to reduce the operating
pressure.
23. The apparatus of claim 21 wherein the pressure regulator is
operably configured, in response to the operating pressure in the
first treatment vessel falling below a pre-determined minimum
operating pressure, to cause pressurized gas to enter the first
treatment vessel to raise the operating pressure.
24. The apparatus of claim 20 further comprising: a second
treatment vessel having a second feedstock inlet for receiving a
second feedstock, and a second product outlet for discharging
refined hydrocarbon products; the second treatment vessel being
operably configured to receive, as the second feedstock at its
second feedstock inlet, the separated hydrocarbon products
discharged from the first product outlet; the second treatment
vessel being operably configured to cause hydrocarbon products in
the second feedstock to be separated from the second feedstock and
to be discharged via the second product outlet as the refined
hydrocarbon products.
25. The apparatus of claim 24 wherein the first and second
treatment vessels are vertically stacked for treating the feedstock
in stages, with interstage feeding between the first product outlet
and the second feedstock inlet being configured to occur via the
force of gravity.
26. The apparatus of claim 20 wherein the secondary separation
container includes a weir operably configured to collect
hydrocarbon products which rise toward an upper surface of the
accumulated low specific gravity portion.
27. The apparatus of claim 20 wherein the primary separation
container includes a feed manifold operably configured to receive a
flow of the feedstock from the inlet, to spread out the feedstock
flow to reduce turbulence intensity and provide a generally uniform
flow of feedstock into the primary separation container, and also
to facilitate precipitation coalescence of asphaltenes in cases
where the feedstock includes a paraffinic diluent.
28. The apparatus of claim 20 wherein an aspect ratio defined as
the treatment vessel's length to the treatment vessel's diameter is
about 20 to 7.
29. A system for treating a hydrocarbon feedstock having a specific
gravity differential between components of the feedstock, the
system comprising: a treatment vessel operably configured for
pressure containment, having a feedstock inlet for receiving the
feedstock and a product outlet for discharging hydrocarbon
products; at least one separation container in the treatment vessel
operably configured to receive the feedstock from the feedstock
inlet, to accumulate a low specific gravity portion of the
feedstock to cause hydrocarbon products in the low specific gravity
portion to separate and rise toward an upper surface of the
accumulated low specific gravity portion, and to discharge the
separated hydrocarbon products to the product outlet; and a
pressure regulator in communication with the treatment vessel and
operable to regulate operating pressure within the treatment vessel
to be within a desired range.
30. The system of claim 29 wherein the at least one separation
container in the treatment vessel comprises: a primary separation
vessel within the treatment vessel for separating out the low
specific gravity portion from a remaining portion of the feedstock;
and a secondary separation vessel within the treatment vessel for
separating out the hydrocarbon products from a remaining portion of
the low specific gravity portion, for discharge to the product
outlet.
31. The system of claim 29 further comprising at least one of: a
recovery system in communication with the pressure regulator and
operable to receive and process vented gaseous products from the
treatment vessel if the operating pressure in the treatment vessel
exceeds a pre-determined maximum operating pressure; and a source
of pressurized gas in communication with the pressure regulator and
operable to cooperate with the pressure regulator to supply gas to
the treatment vessel if the operating pressure in the treatment
vessel below a pre-determined minimum operating pressure.
Description
BACKGROUND
[0001] 1. Field of Invention
[0002] This invention relates generally to hydrocarbon extraction
and more particularly to a process and apparatus for treating a
heavy hydrocarbon feedstock having a specific gravity differential
between components of the feedstock.
[0003] 2. Description of Related Art
[0004] Heavy hydrocarbon feedstocks are generally viscous and may
be entrained with other components such as rock, sand, clay, and
other minerals. As a result, heavy hydrocarbons require processing
to separate useful hydrocarbon products from residue before
transport and refining.
[0005] One example of a heavy hydrocarbon ore deposit is the
Northern Alberta oil sands, which comprises about 70 to about 90
percent by weight of mineral solids including sand and clay, about
1 to about 10 percent by weight of water, and a bitumen or oil
film. The bitumen may be present in amounts ranging from a trace
amount up to as much as 20 percent by weight. Due to the highly
viscous nature of bitumen, when excavated some of the ore may
remain as clumps of oversize ore, requiring sizing to produce a
sized ore feed suitable for processing. The ore may also be frozen
due to the northerly geographic location of many oil sands
deposits, making sizing of the ore more difficult. The sized ore
feed is typically processed by adding water to form a slurry in a
location proximate to the ore deposit, and the resulting slurry is
hydro-transported through a pipeline to a processing plant for
separation of the hydrocarbon products from the sand and other
minerals.
[0006] Low specific gravity hydrocarbons may be separated from sand
and water, which generally have higher specific gravity, by
accumulating the feedstock in a separation vessel and allowing
gravity separation to occur. Such a separation vessel may have a
large diameter relative to side wall height and may include a
conical bottom for sand removal. For adequate separation of
hydrocarbons, the relatively quiescent conditions of the
accumulated feedstock may be required in the vessel, which has the
adverse effect of allowing neutral density asphaltene mats to
accumulate at an interface between the separated hydrocarbon
products and the water. These asphaltene mats accumulate as rag
layers and may be difficult to remove.
[0007] There remains a need for improved processes and apparatus
for treating heavy hydrocarbon feedstocks.
SUMMARY
[0008] In accordance with one aspect of the invention there is
provided an apparatus for treating a heavy hydrocarbon feedstock
having a specific gravity differential between components of the
feedstock. The apparatus includes a treatment vessel having an
inlet for receiving the feedstock. The apparatus also includes a
primary separation container located in the treatment vessel, the
primary separation container being operable to accumulate feedstock
to cause a low specific gravity portion of the feedstock to
separate and rise to an upper surface of the accumulated feedstock.
The apparatus also includes a first weir for collecting the low
specific gravity portion from the surface of the accumulated
feedstock in the primary separation container. The apparatus
further includes a first outlet in the primary separation
container, the first outlet being operably configured to receive
settling solids in the accumulated feedstock and to produce a first
discharge stream at the first outlet. The apparatus also includes a
secondary separation container located in the treatment vessel to
receive the collected low specific gravity portion, the secondary
separation container being operable to accumulate the collected low
specific gravity portion to cause hydrocarbon products to separate
and rise to an upper surface of the accumulated low specific
gravity portion of the feedstock. The apparatus further includes a
product outlet for collecting the hydrocarbon products from the
upper surface of the accumulated low specific gravity portion to
produce a hydrocarbon product stream at the product outlet.
[0009] The apparatus may include a feed manifold operably
configured to receive a flow of feedstock from the inlet and cause
the feedstock to flow along the feed manifold to the primary
separation container for conditioning the feedstock flow to
facilitate separation of the low specific gravity portion in the
primary separation container.
[0010] The feed manifold may include a plurality of adjacently
located open channels extending between the inlet and the primary
separation container, the open channels being operable to reduce
turbulence intensity in the feedstock flow.
[0011] The feed manifold may be operably configured to cause a
feedstock flow into the primary separation container having a
Reynolds Number of about 20,000.
[0012] The primary separation container may include a downwardly
inclined base operably configured to direct settling solids in the
accumulated feedstock toward the first outlet of the treatment
vessel.
[0013] The downwardly inclined base defines a first portion of the
primary separation container and the primary separation container
may further include a second portion of the primary separation
container located to receive the solids from the downwardly
inclined base, the first outlet being located at a low point in the
second portion of the primary separation container.
[0014] The secondary separation container may be located generally
below the downwardly inclined base of the primary separation
container.
[0015] The first weir may include a catchment located behind the
weir, the catchment being operable to receive the collected low
specific gravity portion and to direct the collected low specific
gravity portion to the secondary separation container.
[0016] The apparatus may include a conduit extending between the
catchment and the secondary separation container.
[0017] The first weir may include a weir having a J-shaped cross
section.
[0018] The first weir may include a serpentine weir.
[0019] The first weir may be positioned to collect the low specific
gravity portion from a first area of the upper surface of the
accumulated feedstock in the primary separation container, and the
apparatus may further include a second weir positioned proximate a
second area of the upper surface of the accumulated feedstock in
the primary separation container, the second weir being operable to
permit feedstock in the second area from which a substantial
portion of the low specific gravity portion has been collected to
overflow to produce a second discharge stream at a second
outlet.
[0020] The apparatus may include a first launder box located to
receive and accumulate overflowing feedstock from the second weir
and the second outlet may be located at a low point in the first
launder box.
[0021] The second discharge stream may include at least water and a
fine solids component.
[0022] The first discharge stream may include at least water and a
coarse solids component.
[0023] The first discharge stream may further include
asphaltenes.
[0024] The apparatus may include a third outlet located in the
secondary separation container of the treatment vessel, the third
outlet being located at a low point in the secondary separation
container for producing a third discharge stream at the third
outlet.
[0025] The third outlet may include a water boot disposed below the
secondary separation container, the water boot having an outlet for
discharging the third discharge stream.
[0026] The product outlet may include a third weir located in the
secondary separation container to cause the hydrocarbon products in
the accumulated low specific gravity portion to overflow to produce
the hydrocarbon stream at the product outlet.
[0027] The product outlet may include a second launder box located
to receive and accumulate the overflowing low specific gravity
portion from the third weir and the product outlet may be located
at a low point in the second launder box.
[0028] The feedstock may include an added diluent and the
hydrocarbon product may include a hydrocarbon product portion and a
diluent portion.
[0029] The added diluent may include one of a paraffinic diluent
and a naphthenic diluent.
[0030] The feedstock may include at least about 60% diluent.
[0031] The treatment vessel may include a pressure containment
vessel and may further include at least one gas outlet operably
configured to discharge gaseous products released from the
feedstock during treatment.
[0032] The apparatus may include a regulator regulating an
operating pressure in the treatment vessel.
[0033] The regulator may be operably configured to regulate the
operation pressure by causing the at least one gas outlet to be
activated to release gaseous products when the operating pressure
in the treatment vessel is above a pre-determined maximum operating
pressure, and by introducing a supplementary pressurizing gas when
the operating pressure in the treatment vessel falls below a
pre-determined minimum operating pressure.
[0034] In accordance with another aspect of the invention there is
provided a process for treating a heavy hydrocarbon feedstock
having a specific gravity differential between components of the
feedstock. The process involves receiving the feedstock at an inlet
of a treatment vessel, and accumulating feedstock in a primary
separation container in the treatment vessel to cause a low
specific gravity portion of the feedstock to separate and rise to
an upper surface of the accumulated feedstock. The process also
involves collecting the low specific gravity portion from the
surface of the accumulated feedstock in the primary separation
container, and directing settling solids in the accumulated
feedstock toward a first outlet of the treatment vessel to produce
a first discharge stream at the first outlet. The process further
involves accumulating the collected low specific gravity portion in
a secondary separation container in the treatment vessel to cause
hydrocarbon products to separate and rise to an upper surface of
the accumulated low specific gravity portion, and collecting the
hydrocarbon products from the upper surface of the accumulated low
specific gravity portion to produce a hydrocarbon product stream at
a product outlet.
[0035] Receiving the feedstock may involve receiving a flow of
feedstock at the inlet and causing the feedstock to flow along a
feed manifold between the inlet and the primary separation
container for conditioning the feedstock flow to facilitate
separation of the low specific gravity portion in the primary
separation container.
[0036] Conditioning the feedstock flow may involve causing the
feedstock to flow along a plurality of adjacently located open
channels extending between the inlet and the primary separation
container, the open channels being operable to reduce turbulence
intensity in the feedstock flow.
[0037] Causing the feedstock to flow along the feed manifold may
involve causing a feedstock flow into the primary separation
container having a Reynolds Number of about 20,000, which is
significantly higher than flow rates in conventional API
separators.
[0038] Directing settling solids in the accumulated feedstock
toward the first outlet of the treatment vessel may involve causing
the solids to be directed along a downwardly inclined base of the
primary separation container toward the first outlet.
[0039] The downwardly inclined base may define a first portion of
the primary separation container and the method may further involve
receiving the settling solids in a second portion of the primary
separation container located to receive the solids from the
downwardly inclined base, the first outlet being located at a low
point in the second portion of the primary separation
container.
[0040] Accumulating the low specific gravity portion in the
secondary separation container may involve accumulating the low
specific gravity portion in a secondary separation container
located generally below the downwardly inclined base of the primary
separation container.
[0041] Collecting the low specific gravity portion may involve
overflowing the low specific gravity portion at a first weir
disposed to receive an overflow stream from the primary separation
container.
[0042] Collecting the low specific gravity portion may involve
receiving the low specific gravity portion overflowing the first
weir in a catchment located behind the weir and directing the
collected low specific gravity portion to the secondary separation
container.
[0043] Directing the collected low specific gravity portion to the
secondary separation container may include causing the collected
low specific gravity portion to flow through a conduit extending
between the catchment and the secondary separation container.
[0044] Receiving the low specific gravity portion at the first weir
may involve receiving the low specific gravity portion at a weir
having a J-shaped cross section.
[0045] Receiving the low specific gravity portion at the first weir
may involve receiving the low specific gravity portion at a
serpentine weir.
[0046] Collecting the low specific gravity portion may involve
collecting the low specific gravity portion from a first area of
the upper surface of the accumulated feedstock and may further
involve overflowing feedstock from a second area of the upper
surface from which a substantial portion of the low specific
gravity portion has been collected to produce a second discharge
stream at a second outlet of the treatment vessel.
[0047] Overflowing feedstock from the second area of the upper
surface may involve causing the feedstock to overflow into a first
launder box, the second outlet being located at a low point in the
first launder box.
[0048] Producing the second discharge stream may involve producing
a second discharge stream including at least water and a fine
solids component.
[0049] Producing the first discharge stream may involve producing a
discharge stream including at least water and a coarse solids
component.
[0050] Producing the first discharge stream may involve producing a
discharge stream including asphaltenes.
[0051] The process may involve producing a third discharge stream
at a third outlet of the treatment vessel, the third outlet being
located at a low point of the secondary separation container.
[0052] Producing the third discharge stream at the third outlet may
involve causing aqueous components to be collected in a water boot
disposed below the secondary separation container, the water boot
having an outlet for discharging the third discharge stream.
[0053] Collecting the hydrocarbon products may involve overflowing
the accumulated low specific gravity portion.
[0054] Overflowing the accumulated low specific gravity portion may
involve causing the hydrocarbon products in the low specific
gravity portion of the feedstock to overflow into a second launder
box, the product outlet being located at a low point in the second
launder box.
[0055] The feedstock may include an added diluent, and collecting
the hydrocarbon products may involve collecting a hydrocarbon
product portion and a diluent portion.
[0056] The added diluent may include one of a paraffinic diluent
and a naphthenic diluent.
[0057] The feedstock may include at least about 60% diluent.
[0058] The treatment vessel may include a pressure containment
vessel and the method may further involve causing gaseous products
released from the feedstock during treatment to be discharged from
the treatment vessel through at least one gas outlet.
[0059] The process may involve regulating an operating pressure in
the treatment vessel.
[0060] Regulating the operation pressure may involve causing the at
least one gas outlet to be activated to release gaseous products
when the operating pressure in the treatment vessel may be above a
pre-determined maximum operating pressure, and introducing a
supplementary pressurizing gas when the operating pressure in the
treatment vessel falls below a pre-determined minimum operating
pressure.
[0061] In accordance with another aspect of the invention there is
provided an apparatus for treating a heavy hydrocarbon feedstock
having a specific gravity differential between components of the
feedstock. The apparatus includes provisions for receiving the
feedstock at an inlet of a treatment vessel, and provisions for
accumulating feedstock in a primary separation container in the
treatment vessel to cause a low specific gravity portion of the
feedstock to separate and rise to an upper surface of the
accumulated feedstock. The apparatus also includes provisions for
collecting the low specific gravity portion from the surface of the
accumulated feedstock in the primary separation container, and
provisions for directing settling solids in the accumulated
feedstock toward a first outlet of the treatment vessel to produce
a first discharge stream at the first outlet. The apparatus further
includes provisions for accumulating the collected low specific
gravity portion in a secondary separation container in the
treatment vessel to cause hydrocarbon products to separate and rise
to an upper surface of the accumulated low specific gravity
portion, and provisions for collecting the hydrocarbon products
from the upper surface of the accumulated low specific gravity
portion to produce a hydrocarbon product stream at a product
outlet.
[0062] Other aspects and features of the present invention will
become apparent to those ordinarily skilled in the art upon review
of the following description of specific embodiments of the
invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] In drawings which illustrate embodiments of the
invention,
[0064] FIG. 1 is a partially cut-away perspective view of a
treatment vessel apparatus in accordance with a first embodiment of
the invention;
[0065] FIG. 2 is a cross sectional view of the treatment vessel
taken along a line 2-2 in FIG. 1;
[0066] FIG. 3 is another cross sectional view of the treatment
vessel taken along a line 3-3 in FIG. 2; and
[0067] FIG. 4 is further cross sectional view of the treatment
vessel taken along a line 4-4 in FIG. 2.
DETAILED DESCRIPTION
[0068] Referring to FIG. 1, an apparatus for treating a heavy
hydrocarbon feedstock according to a first embodiment of the
invention is shown generally at 100. The apparatus 100 includes a
treatment vessel 102 having an inlet 104 for receiving the
feedstock. The feedstock has a specific gravity differential
between components of the feedstock.
[0069] In this embodiment the treatment vessel 102 includes a
cylindrical portion 106 having first and second dome-shaped end
walls 108 and 110. The cylindrical section 106 may be fabricated
from a carbon steel pipe section having a wall thickness of about
12 mm. In other embodiments where the feedstock is corrosive, the
inside surfaces of the treatment vessel 102 may be treated to
resist corrosion or a corrosion resistant metal may be used to
fabricate the treatment vessel. In one embodiment the treatment
vessel 102 may have a length of about 20 meters and a diameter of
about 7 meters. Advantageously, fabrication of the treatment vessel
102 may occur at an off-site location, since the aspect ratio of
the cylindrical section 106 would permit subsequent transport to
the processing location. In contrast, many prior art conical bottom
separators must be fabricated on-site due to their large
diameter.
[0070] The apparatus 100 also includes a primary separation
container 112 located in the treatment vessel 102. The treatment
vessel 102 is shown in cross-section in FIG. 2. Referring to FIG.
2, the primary separation container 112 is operable to accumulate
feedstock to cause a low specific gravity portion of the feedstock
to separate and rise to an upper surface 114 of the accumulated
feedstock.
[0071] The primary separation container 112 also includes a first
weir 116 and a catchment 117 located behind the first weir for
collecting the low specific gravity portion from the surface of the
accumulated feedstock. The primary separation container 112 further
includes a first outlet 119 operably configured to receive settling
solids in the accumulated feedstock and to produce a first
discharge stream at the first outlet.
[0072] The treatment vessel 102 further includes a secondary
separation container 118. The secondary separation container 118 is
located to receive the low specific gravity portion collected at
the catchment 117. Referring back to FIG. 1, in the embodiment
shown the primary separation container 112 includes a conduit 120
having an inlet opening 122 in the catchment 117 for receiving the
collected low specific gravity portion and an outlet 124 for
discharging the collected low specific gravity portion into the
secondary separation container 118.
[0073] The secondary separation container 118 is operable to
accumulate the collected low specific gravity portion to cause
hydrocarbon products to separate and rise to an upper surface 126
of the accumulated low specific gravity portion of the
feedstock.
[0074] Referring back to FIG. 2, the treatment vessel 102 further
includes a product outlet 128 for collecting the hydrocarbon
products from the upper surface 126 of the accumulated low specific
gravity portion to produce a hydrocarbon product stream at the
product outlet. In this embodiment the product outlet 128 is
located in a second launder box 152 defined by a third weir 150.
The product outlet 128 is located at a low point in the second
launder box 152.
[0075] In this embodiment the treatment apparatus 102 includes a
feed manifold 130, which is operably configured to receive a flow
of feedstock from the inlet 104 and to cause the feedstock to flow
along the feed manifold to the primary separation container 112.
The feed manifold is operable to direct the feedstock flow to the
primary separation container 112 while conditioning the flow to
facilitate separation of the low specific gravity portion in the
primary separation container.
[0076] The apparatus 100 is shown in cross section in FIG. 3.
Referring to FIG. 3, the feed manifold 130 includes a plurality of
baffles 132 forming a plurality of channels 134, which receive a
flow of feedstock from the inlet 104 and channel the feedstock flow
to the primary separation container 112. In other embodiments, the
feed manifold 130 may include a plurality of ridges for
conditioning the feedstock flow (not shown) in place of the baffles
132.
[0077] Referring back to FIG. 2, in this embodiment the primary
separation container 112 includes a downwardly inclined base 136
operably configured to direct settling solids in the accumulated
feedstock toward the first outlet 119 of the treatment vessel 102.
The downwardly inclined base 136 also forms a dividing wall between
the primary separation container 112 and the secondary separation
container 118.
[0078] In the embodiment shown, the first weir 116 has a generally
J-shaped cross section, which defines the catchment 117. In other
embodiments apparatus 100 may include a serpentine weir. Serpentine
weirs have increased length in the path of the flow, which
increases the flow rate capacity of the weir.
[0079] The apparatus 100 also includes a second weir 142 positioned
proximate the end wall 108 and defining a first launder box 138
located to receive and accumulate feedstock overflowing from the
second weir 142. The second weir 142 separates the first launder
box 138 from the primary separation container 112. The apparatus
100 also includes a second outlet 146, which is located at a low
point in the first launder box 138.
[0080] The apparatus 100 also includes a third outlet 148 located
at a low point of the secondary separation container 118. In one
embodiment the third outlet 148 comprises a water boot.
[0081] In one embodiment the treatment vessel 102 is operably
configured to operate under a positive pressure, and the treatment
vessel includes a gas outlet 154, which is operable to discharge
gaseous products released from the feedstock during treatment. In
this embodiment, the gas outlet 154 is in communication with first
and second conduits 158 and 160 through a regulator 156 for
regulating operating pressure in the treatment vessel 102, as
described later.
[0082] A further cross section through the secondary separation
container 112 of the apparatus 100 is shown in cross section in
FIG. 4. In FIG. 4, a portion of the downwardly inclined base 136 is
shown, and the container 118 extends from under the downwardly
inclined base to the third weir 150.
Operation
[0083] The operation of the treatment vessel 102 is described in
greater detail with reference to FIG. 1 and FIG. 2. Referring to
FIG. 2, a flow of heavy hydrocarbon feedstock is received at the
inlet 104 and directed to the feed manifold 130. In general, the
flow rate of the feedstock flow may fluctuate over time.
[0084] In one embodiment the heavy hydrocarbon feedstock comprises
heated and de-aerated bitumen froth. An exemplary bitumen froth may
comprise about 80% hydrocarbon products, about 15% water, and about
5% solids. The solids may include sand, minerals, and other fine
solids. The bitumen froth may also have an added diluent. For
example, the diluent may comprise napthatenic or paraffinic
compounds, and may be present in a proportion of 60-80% of the
feedstock. Advantageously, the configuration of the treatment
vessel 102 provides relatively shallow accumulations in the primary
separation container 112 and the secondary separation container
118, thus limiting the inventory of feedstock, and hence diluent,
in the treatment vessel. Conventional diluents are generally of
more value than the hydrocarbon products being extracted and thus
minimizing the diluent volume required is desirable.
[0085] The feedstock components generally have a specific gravity
differential that is sufficient to cause gravity separation under
horizontal flow conditions through the primary separation container
112. The hydrocarbon components (including diluent, if added) will
generally have a specific gravity of less than unity, while the
sand and other minerals will generally have a specific gravity
greater than unity. Fine solids, such as silt, may be largely
suspended in the water, which will have a specific gravity of close
to unity.
[0086] Referring to FIG. 3, the feedstock is separated into a
plurality of separate flows by the baffles 132 into the open
channels 134, which spread out the feedstock flow to provide a
uniform feed into the primary separation container 112. The open
channels 134 operate to reduce turbulence intensity and prevent
formation of eddy currents in the feedstock flow, which would tend
to disrupt or delay onset of gravity separation. For efficient
operation of the apparatus 100, the flow rate of the feedstock
should be as high as possible, without generating excessive
turbulence in the primary separation container 112. Currents due to
turbulence may work against upward movement and separation of the
low specific gravity portion of the feedstock. In one exemplary
embodiment the feedstock flow into the primary separation vessel
112 has a Reynolds number of about 20,000.
[0087] In embodiments where the feedstock includes a paraffinic
diluent, the feed manifold also conditions the stream by providing
sufficient time to permit precipitation coalescence of asphaltenes
to occur.
[0088] The feedstock entering the primary separation container 112
accumulates to a level of the weir 116. In embodiments where the
feedstock flow rate is very high, the weir 116 may be configured in
a serpentine shape to increase the flow volume over the lip into
the catchment 117 for controlling accumulation level in the primary
separation container 112. Advantageously, the first weir 116
controls the accumulation level of feedstock in the primary
separation container 112, despite variations in feedstock flow rate
at the inlet 104.
[0089] The lower specific gravity portion of the feedstock rises to
the upper surface 114 of the accumulated feedstock, while higher
specific gravity sand and other minerals begin to settle out along
the downwardly inclined base 136. The base 136 also directs the
solids along toward a portion 164 of the primary separation
container 112. In embodiments where precipitation of asphaltenes
occurs, precipitated asphaltenes are also directed along the base
toward the portion 164 of the primary separation container 112. A
cylindrical portion 106 of the treatment vessel provides a rounded
base in the container portion 164, which further aids in directing
solids and asphaltenes towards the first outlet 119, thus producing
a first discharge stream as a slurry of predominantly coarse
solids, asphaltenes, and water. Advantageously, the downwardly
inclined base 136 also serves to slow down the cross-sectional flow
rate of the feedstock proximate the first weir 116.
[0090] The first weir 116 collects a substantial portion of low
specific gravity hydrocarbon products in the catchment 117. The
collected low specific gravity portion is received at the inlet 122
of the conduit 120 and directed to the secondary separation
container 118. The collected low specific gravity portion may
include some proportion of water, since complete separation at the
first weir 116 of hydrocarbon products from water is not
practically achievable due to a under high flow rate regimen.
[0091] The first weir 116 thus collects a substantive portion of
the low specific gravity portion of the feedstock from an area 140
between an end of the feed manifold 130 and the first weir 116. The
first weir 116 also presents a barrier to passage of the
hydrocarbon products past the weir to an area 144 between the first
weir 116 and the second weir 142. Accordingly, the feedstock
portion overflows at the second weir 142 has relatively low
hydrocarbon product content and the first launder box 138 produces
a second discharge stream that comprises predominantly water and
fine solids.
[0092] Advantageously, in this embodiment the primary separation
container 112 has a relatively shallow separation pool, which
facilitates construction of the secondary separation container 118
generally below the primary separation container.
[0093] The low specific gravity portion collected at the first weir
116 is conducted to the secondary separation container 118 and
accumulates to a level of the third weir 150. As described above,
the collected low specific gravity portion comprises predominantly
water and hydrocarbon product since a substantial portion of the
solids and asphaltenes are removed in the primary separation
container 112. However, mixing in the primary separation container
due to residual turbulence and a relatively short retention time
under high flow rates may cause the collected low specific gravity
portion to include at least some proportion of water. The
hydrocarbon products in the secondary separation container 118
separate and rise to an upper surface 126 while aqueous components
are drawn off as a third discharge stream at the third outlet 148.
The third discharge stream thus predominantly comprises water,
although some sand, asphaltenes, and/or other hydrocarbon products
may be entrained in the third discharge stream.
[0094] As the collected low specific gravity portion continues to
flow into the secondary separation container 118, the hydrocarbon
products will overflow at the weir 150 into the second launder box
152, where the hydrocarbon products are discharged at the product
outlet 128 as a hydrocarbon product stream. The hydrocarbon product
stream may comprise a significant proportion of diluent, which may
be recovered from the product stream for re-use.
[0095] As disclosed earlier, during operation of the apparatus 100,
gaseous products may be released from the feedstock causing
increased operating pressure in the treatment vessel 102. High
operating pressure may result in damage to the treatment vessel
while low operational pressure may result in the flashing of
feedstock components. The pressure regulator 156 and conduits 158
and 160 facilitate maintaining the operating pressure of the
treatment vessel 102 within a desired safe range. The regulator 156
is in communication with a source of pressurized gas (not shown)
through the first conduit 158, and when the operating pressure in
the treatment vessel falls below a pre-determined minimum operating
pressure the regulator opens to allow the pressurized gas to enter
the vessel. The pressurized gas may be a relatively inert gas, such
as, for example, nitrogen. Alternatively, should the operating
pressure rise above a pre-determined maximum operating pressure,
the regulator 156 opens to vent gaseous products through the second
conduit 160. The second conduit may be in communication with a
recovery system (not shown) for recovering useful gaseous products
or for safe disposal of the gaseous products.
[0096] In one embodiment, two or more of apparatus 100 may be
vertically stacked for treating the feedstock in stages, with
interstage feeding occurring via the force of gravity.
[0097] Advantageously, the flow path through the treatment vessel
102 is free flowing through all stages and thus the possibility of
accumulating asphaltene mats, as described earlier, is limited by
the relatively high flow rate through the vessel.
[0098] While specific embodiments of the invention have been
described and illustrated, such embodiments should be considered
illustrative of the invention only and not as limiting the
invention as construed in accordance with the accompanying
claims.
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