U.S. patent application number 11/960891 was filed with the patent office on 2009-06-25 for intergrated process for in-field upgrading of hydrocarbons.
This patent application is currently assigned to Chevron U.S.A. Inc.. Invention is credited to Daniel Chinn, Zunqing Alice He, Steven F. Sciamanna.
Application Number | 20090159498 11/960891 |
Document ID | / |
Family ID | 40787335 |
Filed Date | 2009-06-25 |
United States Patent
Application |
20090159498 |
Kind Code |
A1 |
Chinn; Daniel ; et
al. |
June 25, 2009 |
INTERGRATED PROCESS FOR IN-FIELD UPGRADING OF HYDROCARBONS
Abstract
A process is provided for in-field upgrading of heavy
hydrocarbons such as whole heavy oil, bitumen, and the like using
supercritical water.
Inventors: |
Chinn; Daniel; (Bay Point,
CA) ; Sciamanna; Steven F.; (Orinda, CA) ; He;
Zunqing Alice; (San Rafael, CA) |
Correspondence
Address: |
CHEVRON CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
Chevron U.S.A. Inc.
|
Family ID: |
40787335 |
Appl. No.: |
11/960891 |
Filed: |
December 20, 2007 |
Current U.S.
Class: |
208/85 |
Current CPC
Class: |
C10G 31/08 20130101;
C10G 47/32 20130101; C10G 45/26 20130101; C10G 9/00 20130101 |
Class at
Publication: |
208/85 |
International
Class: |
C10G 1/00 20060101
C10G001/00 |
Claims
1. An integrated process for in-field upgrading of hydrocarbons
comprising: passing a hydrocarbon feed into an in-field upgrader
from a hydrocarbonaceous production source; mixing the hydrocarbon
feed with a fluid comprising water that has been heated to a
temperature higher than its critical temperature in a mixing zone
to form a mixture; passing the mixture to a reaction zone; reacting
the mixture in the reaction zone under supercritical water
conditions in the absence of externally added hydrogen for a
residence time sufficient to allow upgrading reactions to occur;
withdrawing a single-phase reaction product from the reaction zone;
recovering energy from said reaction product for use in the
hydrocarbonaceous production source; and separating the cooled
reaction product into gas, effluent water, converted hydrocarbons
and unconverted hydrocarbons.
2. The process for in-field upgrading of hydrocarbons according to
claim 1, further comprising the step of applying distillation to
the converted hydrocarbons.
3. The process for in-field upgrading of hydrocarbons according to
claim 2, further comprising the step of blending a distillation
overheads liquid with a distillation bottoms liquid.
4. The process for in-field upgrading of hydrocarbons according to
claim 2, further comprising the steps of: passing dregs to dregs
processing; contacting the dregs with a distillation overheads
liquid; and recycling extracted hydrocarbons back with the
hydrocarbon feed.
5. The process for in-field upgrading of hydrocarbons according to
claim 1, further comprising the steps of: mixing dregs with a fluid
comprising water that has been heated to a temperature higher than
its critical temperature in another mixing zone to form another
mixture; passing the other mixture to another reaction zone;
reacting and extracting hydrocarbons from the other mixture in the
other reaction zone under supercritical water conditions in the
absence of externally added hydrogen for a residence time
sufficient to allow upgrading reactions to occur; and recycling a
reactants product stream from the other reaction zone to the
hydrocarbon feed.
6. The process for in-field upgrading of hydrocarbons according to
claim 5, further comprising the step of applying distillation to
the converted hydrocarbons.
7. The process for in-field upgrading of hydrocarbons according to
claim 6, further comprising the step of blending a distillation
overheads liquid with a distillation bottoms liquid.
8. The process for in-field upgrading of hydrocarbons according to
claim 6, further comprising the step of recycling the distillation
overheads liquid back with the hydrocarbon feed.
9. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the hydrocarbonaceous production source is at
least one selected from the group consisting of heavy crude oil,
tar sands, bitumen, heavy petroleum crude oils, heavy vacuum gas
oils, vacuum residuum, petroleum tar, coal tar, oil shale,
asphaltenes and mixtures thereof.
10. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the water is at least one selected from the group
consisting of drinking water, treated or untreated wastewater,
river water, lake water, seawater, produced water and mixtures
thereof.
11. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the water has a temperature in a range of about
374.degree. C. to about 420.degree. C. and a pressure in a range of
about 3205 to about 4000 psia.
12. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the mixture has an oil/water mass ratio in a range
of about 1:1 to about 1:2.
13. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the reacting has a residence time in a range of
about 8 min to about 30 min.
14. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the energy is recovered from the reaction product
in a plurality of heat exchangers and steam boilers.
15. The process for in-field upgrading of hydrocarbons according to
claim 1, further comprising utilizing the recovered energy in an
enhanced oil recovery or steam assisted gravity drain process.
16. The process for in-field upgrading of hydrocarbons according to
claim 4, wherein the dregs processing is conducted in at least one
selected from the group consisting of a dregs washer, a
mixer-settler unit, and a solids leaching unit.
17. The process for in-field upgrading of hydrocarbons according to
claims 2 or 6, wherein the distillation is conducted in a tray or
packed column.
18. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the operating pressure of the mixing is in a range
of about 3250 to about 3600 psia and the operating temperature of
the mixing is in a range of about 385 to about 420.degree. C.
19. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the operating pressure of the reacting is in a
range of about 3205 to about 10000 psia and the operating
temperature of the reacting is in a range of about 374 to about
1000.degree. C.
20. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the operating pressure of the separating is in a
range of about 150 to about 3500 psia and the operating temperature
of the separating is in a range of about 50 to about 300.degree.
C.
21. The process for in-field upgrading of hydrocarbons according to
claim 1, wherein the separating is conducted in at least one
two-phase separator or three-phase separator.
22. The process for in-field upgrading of hydrocarbons according to
claims 2 or 6, wherein the operating pressure of the distillation
is in a range of about 1 to about 50 psia and the operating
temperature of the distillation is in a range of about 40 to about
90.degree. C.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an integrated process for
in-field upgrading of heavy hydrocarbons such as whole heavy oil,
bitumen, and the like using supercritical water.
BACKGROUND OF THE INVENTION
[0002] Oil produced from a significant number of oil reserves
around the world is simply too heavy to flow under ambient
conditions. This makes it challenging to bring remote, heavy oil
resources closer to the markets. One typical example is the Hamaca
field in Venezuela. In order to render such heavy oils flowable,
one of the most common methods known in the art is to reduce the
viscosity and density by mixing the heavy oil with a sufficient
diluent. The diluent may be naphtha, or any other stream with a
significantly higher API gravity (i.e., much lower density) than
the heavy oil. A diluted, heavy crude with an API of 12 or higher
will normally be transportable by pipeline without significant
problems.
[0003] For a case such as Hamaca, diluted crude oil is sent from
the production wellhead via pipeline to an upgrading facility
located 120 miles away. Two key operations occur at the upgrading
facility: (1) the diluent stream is recovered and recycled back to
the production wellhead in a separate pipeline, and (2) the heavy
oil is upgraded with suitable technology known in the art (coking,
hydrocracking, hydrotreating, etc.) to produce higher-value
products for market. Some typical characteristics of these
higher-value products include: lower sulfur and nitrogen content,
lower metals content, lower total acid number (TAN), lower carbon
residuum content, higher API gravity, and lower viscosity. Most of
these desirable characteristics are achieved by reacting the heavy
oil with hydrogen gas at high temperatures and pressures in the
presence of a catalyst. In the case of Hamaca, the upgraded crude
is sent further to the end-users via tankers.
[0004] These diluent addition/removal processes and
hydrogen-addition or other upgrading processes have a number of
disadvantages:
1. The infrastructure required for the handling, recovery, and
recycle of diluent could be expensive, especially over long
distances. Diluent availability is another potential issue. 2.
Hydrogen-addition processes such as hydrotreating or hydrocracking
require significant investments in capital and infrastructure. 3.
Hydrogen-addition processes also have high operating costs, since
hydrogen production costs are highly sensitive to natural gas
prices. Some remote heavy oil reserves may not even have access to
sufficient quantities of low-cost natural gas to support a hydrogen
plant. These hydrogen-addition processes also generally require
expensive catalysts and resource intensive catalyst handling
techniques, including catalyst regeneration. 4. In some cases, the
refineries and/or upgrading facilities that are located closest to
the production site may have neither the capacity nor the
facilities to accept the heavy oil. 5. Coking is often used at
refineries or upgrading facilities. Significant amounts of
by-product solid coke are rejected during the coking process,
leading to lower liquid hydrocarbon yield. Further, the volume of
the product from the coking process is significantly less than the
volume of the feed crude oil.
SUMMARY OF THE INVENTION
[0005] The present invention achieves the advantage of an
integrated process for in-field upgrading of heavy hydrocarbons
such as whole heavy oil, bitumen, and the like using supercritical
water.
[0006] In an aspect of the invention, an integrated process for
in-field upgrading of hydrocarbons includes:
[0007] passing a hydrocarbon feed into an in-field upgrader from a
hydrocarbonaceous production source;
[0008] mixing the hydrocarbon feed with a fluid comprising water
that has been heated to a temperature higher than its critical
temperature in a mixing zone to form a mixture;
[0009] passing the mixture to a reaction zone;
[0010] reacting the mixture in the reaction zone under
supercritical water conditions in the absence of externally added
hydrogen for a residence time sufficient to allow upgrading
reactions to occur;
[0011] withdrawing a single-phase reaction product from the
reaction zone;
[0012] recovering energy from said reaction product for use in the
hydrocarbonaceous production source; and
[0013] separating the cooled reaction product into gas, effluent
water, converted hydrocarbons and unconverted hydrocarbons.
[0014] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the step of applying distillation to
the converted hydrocarbons.
[0015] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the step of blending a distillation
overheads liquid with a distillation bottoms liquid.
[0016] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the steps of:
[0017] passing dregs to dregs processing;
[0018] contacting the dregs with a distillation overheads liquid;
and
[0019] recycling extracted hydrocarbons back with the hydrocarbon
feed.
[0020] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the steps of: [0021] mixing dregs
with a fluid comprising water that has been heated to a temperature
higher than its critical temperature in another mixing zone to form
another mixture; [0022] passing the other mixture to another
reaction zone; [0023] reacting and extracting hydrocarbons from the
other mixture in the other reaction zone under supercritical water
conditions in the absence of externally added hydrogen for a
residence time sufficient to allow upgrading reactions to occur;
and [0024] recycling a hydrocarbon product from the other reaction
zone to the hydrocarbon feed.
[0025] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the step of applying distillation to
the converted hydrocarbons.
[0026] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the step of blending a distillation
overheads liquid with a distillation bottoms liquid.
[0027] Optionally, the above process for in-field upgrading of
hydrocarbons further includes the step of recycling the
distillation overheads liquid back with the hydrocarbon feed.
[0028] Optionally, in the above process for in-field upgrading of
hydrocarbons, the hydrocarbonaceous production source is at least
one selected from the group consisting of heavy crude oil, tar
sands, bitumen, heavy petroleum crude oils, heavy vacuum gas oils,
vacuum residuum, petroleum tar, coal tar, oil shale, asphaltenes
and mixtures thereof.
[0029] Optionally, in the above process for in-field upgrading of
hydrocarbons, the water is at least one selected from the group
consisting of drinking water, treated or untreated wastewater,
river water, lake water, seawater, produced water and mixtures
thereof.
[0030] Optionally, in the above process for in-field upgrading of
hydrocarbons, the water has a temperature in a range of about
374.degree. C. to about 420.degree. C. and a pressure in a range of
about 3205 to about 4000 psia.
[0031] Optionally, in the above process for in-field upgrading of
hydrocarbons, the mixture has an oil/water mass ratio in a range of
about 1:1 to about 1:2.
[0032] Optionally, in the above process for in-field upgrading of
hydrocarbons, the reacting has a residence time in a range of about
8 min to about 30 min.
[0033] Optionally, in the above process for in-field upgrading of
hydrocarbons, the energy is recovered from the reaction product in
a plurality of heat exchangers and steam boilers.
[0034] Optionally, the above process for in-field upgrading of
hydrocarbons further includes utilizing the recovered energy in an
enhanced oil recovery or steam assisted gravity drain process.
[0035] Optionally, in the above process for in-field upgrading of
hydrocarbons, the dregs processing is conducted in at least one
selected from the group consisting of a dregs washer, a
mixer-settler unit, and a solids leaching unit.
[0036] Optionally, in the above process for in-field upgrading of
hydrocarbons, the distillation is conducted in a tray or packed
column.
[0037] Optionally, in the above process for in-field upgrading of
hydrocarbons, the operation, pressure of the mixing is in a range
of about 3250 to about 3600 psia and the operating temperature of
the mixing is in a range of about 385 to about 420.degree. C.
[0038] Optionally, in the above process for in-field upgrading of
hydrocarbons, the operating pressure of the reacting is in a range
of about 3205 to about 10000 psia and the operating temperature of
the reacting is in a range of about 374 to about 1000.degree.
C.
[0039] Optionally, in the above process for in-field upgrading of
hydrocarbons, the operating pressure of the separating is in a
range of about 150 to about 3500 psia and the operating temperature
of the separating is in a range of about 50 to about 300.degree.
C.
[0040] Optionally, in the above process for in-field upgrading of
hydrocarbons, the separating, is conducted in at least one
two-phase separator or three-phase separator.
[0041] Optionally, in the above process for in-field upgrading of
hydrocarbons, the operating pressure of the distillation is in a
range of about 1 to about 50 psia and the operating temperature of
the distillation is in a range of about 40 to about 90.degree.
C.
DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is a process flow diagram of an embodiment of the
present invention.
[0043] FIG. 2 is a process flow diagram of another embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0044] So that the above recited features and advantages of the
present invention can be understood in detail, a more particular
description of the invention, briefly summarized above, may be had
by reference to the embodiments thereof that are illustrated in the
appended figures. It is to be noted, however, that the appended
figures illustrate only a typical embodiment of this invention and
is therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
[0045] Embodiments describing the process of the present invention
are referenced in FIGS. 1 and 2. More specifically, the following
embodiments describe the processes for implementing the present
invention.
Reactants
[0046] Water and hydrocarbons (HC), preferably heavy hydrocarbons
are the two reactants employed in a process according to the
present invention.
[0047] Any heavy hydrocarbon from a hydrocarbonaceous production
source can be suitably upgraded by a process according to the
present invention. Preferred are heavy hydrocarbons having an API
gravity of less than 20.degree.. Also, preferably, the heavy
hydrocarbons contain heteroatoms such as nitrogen and sulfur. Among
the preferred heavy hydrocarbons are heavy crude oil, heavy
hydrocarbons extracted from tar sands commonly called tar sand
bitumen, such as Athabasca tar sand bitumen obtained from Canada,
heavy petroleum crude oils such as Venezuelan Orinoco heavy oil
belt crudes, Boscan heavy oil, heavy hydrocarbon fractions obtained
from crude petroleum oils particularly heavy vacuum gas oils,
vacuum residuum as well as petroleum tar, tar sands and coal tar.
Other examples of heavy hydrocarbon feedstocks which can be used
are oil shale, and asphaltenes.
Water
[0048] Any source of water may be used in the fluid comprising
water in practicing the present invention. Sources of water include
but are not limited to drinking water, treated or untreated
wastewater, river water, lake water, seawater, produced water or
the like.
Mixing
[0049] In accordance with the invention, the heavy hydrocarbon feed
and a fluid comprising water that has been heated to a temperature
higher than its critical conditions (temperature and pressure) are
contacted in a mixing zone prior to entering the reaction zone. In
accordance with the invention, mixing may be accomplished in many
ways and is preferably accomplished by a technique that does not
employ mechanical moving parts. Such means of mixing may include,
but are not limited to, use of static mixers, spray nozzles, sonic
or ultrasonic agitation. The oil and water should be heated and
mixed so that the combined stream will reach supercritical water
conditions in the reaction zone.
[0050] It was found that by avoiding excessive heating of the feed
oil, the formation of byproduct such as solid residues is reduced
significantly. One key aspect of this invention is to design the
heating sequence so that the temperature and the pressure of the
hydrocarbons and water will reach reaction conditions in a
controlled manner. This will avoid excessive local heating of oil,
which will lead to solid formation and lower quality product. In
order to achieve better performance, the oil should only be heated
up with sufficient water present and around the hydrocarbon
molecules. This requirement can be met by mixing oil with water
before heating up.
[0051] In FIG. 1, water is heated to a temperature higher than
critical conditions, and then mixed with oil. The temperature of
heavy oil feed should be kept in the range of about 100 to
343.degree. C. to avoid thermal cracking but still high enough to
maintain a reasonable pressure drop. The water stream temperature
should be high enough to make sure that after mixing with oil, the
temperature of the oil-water mixture is still higher than the water
supercritical temperature. In this embodiment, the oil is actually
heated by water in a direct contact heat exchange. An abundance of
water molecules surrounding the hydrocarbon molecules will
significantly suppress condensation reactions and therefore reduce
formation of coke and solid product.
[0052] The required temperature of the supercritical water stream
can be estimated based on the reaction temperature and water to oil
ratio. Since the heat capacity of water changes significantly in
the range near its critical conditions for a given reaction
temperature, the required temperature for the supercritical water
stream increases almost exponentially with decreasing water-to-oil
ratio. The lower the water-to-oil ratio, the higher the temperature
of the supercritical water stream. The relationship, however, is
very nonlinear since a higher supercritical water stream
temperature leads to a lower heat capacity (far away from the
critical point).
Reaction Conditions
[0053] After the reactants have been mixed, they are passed into a
reaction zone in which they are allowed to react under temperature
and pressure conditions of supercritical water, i.e. supercritical
water conditions, in the absence of externally added hydrogen, for
a residence time sufficient to allow upgrading reactions to occur.
The reaction is preferably allowed to occur in the absence of
externally added catalysts or promoters, although the use of such
catalysts and promoters is permissible in accordance with the
present invention.
[0054] "Hydrogen" as used herein in the phrase, "in the absence of
externally added hydrogen" means hydrogen gas. This phrase is not
intended To exclude all sources of hydrogen that are available as
reactants. Other molecules such as saturated hydrocarbons may act
as a hydrogen source during the reaction by donating hydrogen to
other unsaturated hydrocarbons. In addition, H.sub.2 may be formed
in-situ during the reaction through steam reforming of
hydrocarbons.
[0055] The reaction zone preferably comprises a reactor, which is
equipped with a means for collecting the reaction products
(syncrude, water, and gases), and a section, preferably at the
bottom, where any metal containing compounds/organometallics or
solids (the "dreg stream") may accumulate.
[0056] Supercritical water conditions include a temperature from
374.degree. C. (the critical temperature of water) to 1000.degree.
C., preferably from 374.degree. C. to 600.degree. C. and most
preferably from 374.degree. C. to 420.degree. C., a pressure from
3205 (the critical pressure of water) to 10000 psia, preferably
from 3205 to 7200 psia and most preferably from 32.05 to 4000 psia,
an oil/water mass ratio from 11:0.1 to 1:10, preferably from 1:0.5
to 1:3 and most preferably about 1:1 to 1:2.
[0057] The reactants are allowed to react under these conditions
for a sufficient time to allow upgrading reactions to occur.
Preferably, the residence time will be selected to allow the
upgrading reactions to occur selectively and to the fullest extent
without having undesirable side reactions of coking or residue
formation. Reactor residence times may be from 1 minute to 6 hours,
preferably from 8 minutes to 2 hours and most preferably from 8 to
30 minutes.
Reaction Product Cooling and Heat Integration with Field
Production
[0058] After the reaction has progressed sufficiently, a single
phase reaction product is withdrawn from the reaction zone and
cooled in a series of heat exchangers and steam boilers from a
temperature of about 380 to 420.degree. C. and pressure of about
3400 to 3600 psia to the final desired condition for phase
separation which is preferably no lower than 150.degree. C. and
about 3400 psia. The first heat exchanger is a steam boiler,
whereby the reaction product is cooled to a temperature of about
300.degree. C. from one zone of the heat exchanger, and 80% quality
steam at 900 psia steam is produced from the other zone. This steam
(recovered energy from reaction product) is sent to the bitumen
production field for steam injection in an enhanced oil recovery
(EOR) operation, a steam assisted gravity drain (SAGD) operation,
or any other hydrocarbon production operation where steam injection
is required. The subsequent cooling steps of the 300.degree. C.
reaction product may include any combination of feed-effluent heat
exchange steps to preheat inlet water streams, oil streams, and
production of lower pressure steam (50 psia, 150 psia, 300 psia)
for internal use within the process.
Reaction Product Separation
[0059] After cooling, the reaction product stream is separated into
gas, effluent water, and upgraded hydrocarbon phases. This
separation is preferably done by cooling the stream and using one
or more two-phase separators, three-phase separators, or other
gas-oil-water separation device known in the art. However, any
method of separation can be used in accordance with the
invention.
[0060] The composition of gaseous product obtained by treatment of
the heavy hydrocarbons in accordance with the process of the
present invention will depend on feed properties and typically
comprises light hydrocarbons, water vapor, acid gas (CO.sub.2 and
H.sub.2S), methane and hydrogen. The effluent water may be used,
reused or discarded. It may be recycled to e.g. the feed water
tank, the feed water treatment system or to the reaction zone.
[0061] The upgraded hydrocarbon product, which is sometimes
referred to as "syncrude" herein may be upgraded further or
processed into other hydrocarbon products using methods that are
known in the hydrocarbon processing art.
[0062] The process of the present invention may be carried out
either as a continuous or semi-continuous process or a batch
process or as a continuous process. In the continuous process, the
entire system operates with a feed stream of oil and a separate
feed stream of supercritical water and reaches a steady state;
whereby all the flow rates, temperatures, pressures, and
composition of the inlet, outlet, and recycle streams do not vary
appreciably with time.
[0063] While not being bound to any theory of operation, it is
believed that a number of upgrading reactions are occurring
simultaneously at the supercritical water conditions used in the
present process. In a preferred embodiment of the invention, the
major chemical/upgrading reactions are believed to be:
Thermal Cracking: C.sub.xH.sub.y+H.sub.2.fwdarw.lighter
hydrocarbons Steam Reforming:
C.sub.xH.sub.y+2xH.sub.2O.fwdarw.xCO.sub.2+(2x+y/2)H.sub.2
Demetalization:
C.sub.xH.sub.yNi.sub.w+H.sub.2.fwdarw.Ni--HC+lighter hydrocarbons
Desulfurization:
C.sub.xH.sub.yS.sub.z+H.sub.2.fwdarw.H.sub.2S+lighter
hydrocarbons
[0064] The exact pathway may depend on the reactor operating
conditions (temperature, pressure, W/O mass ratio), reactor design
(mode of contact/mixing, sequence of heating), and hydrocarbon
feedstock.
Syncrude Distillation
[0065] The syncrude product is sent to a distillation column, which
serves to (1) remove light ends from the syncrude prior to storage
and transportation, and (2) to provide an overhead liquid stream
that is lighter (i.e., higher API) than the syncrude feed. A
portion of this overhead liquid stream could be recycled back to
the front end of the process to dilute the feed hydrocarbon to ease
the process (final API of 12-14). Alternately, this recycle stream
may also be used to extract the hydrocarbon liquids from the dregs
stream (see below). The remaining portion may be blended back to
the bottoms stream of the column. Preferably, the column is heated
by feeding in live, steam (150 psia, 188.degree. C.) at the bottom
stage of the column. The overhead of the column is cooled by any
combination of air and water cooling to achieve a temperature of
about 50.degree. C. The column may be a trayed or packed column
such as those known in the petroleum refining art.
Dregs Processing
[0066] The dregs stream refers to the by-product produced in the
supercritical reactor that contains water, unreacted hydrocarbon
liquids, coke-like materials, sulfur-containing materials, and
metal containing compounds/organometallics. One preferred
embodiment of processing the dregs stream is to contact a portion
of the overhead liquid stream from the syncrude distillation unit
with the dregs stream in a mixer-settler unit. The overhead liquid
stream acts as a solvent for extracting the hydrocarbon liquids
from the non-hydrocarbon, solid-like portion of the dregs stream.
The extracted liquids are recycled back to the front end of the
process to mix with the feed hydrocarbon to the supercritical water
reactor. The non-extracted stream from the mixer-settlers are
concentrated with the solids, and is sent to a reactor solids dryer
heated with 300 psia steam. The solids dryer includes a porcupine
heater, screw conveyor, or any other solids drying device known in
the art. Residual liquids from the non-extracted stream are
vaporized, recondensed, and separated to form gaseous products
(sent to fuel or flare header), possibly water (sent to water
treatment unit), and hydrocarbons (recycled along with the
extracted hydrocarbon liquid streams). The solids portion are
transported out via a conveyor belt or other solids-transportion
method known in the art to a solids cooler, and then stored for
eventual disposal or metals reclamation.
[0067] The following embodiments are illustrative of the present
invention, but are not intended to limit the invention in any way
beyond what is contained in the claims which follow.
EMBODIMENT
[0068] In an embodiment of the invention illustrated in FIG. 1, a
heavy hydrocarbon feed stream 101 and a water feed stream 103,
having compositions as shown in TABLES 1 & 2 (Simulated Example
Data), are fed to a mixer 130. As described in more detail above,
the mixer 130 may include, but is not limited to, static mixers,
spray nozzles, and sonic or ultrasonic agitation. The heavy
hydrocarbon feed stream 101 and the water feed stream 103 are mixed
so that a combined stream 104 will reach supercritical water
conditions. The operating pressure of the mixer 130 is in the range
of about 3250 to about 3600 psia. The operating, temperature of the
mixer 130 is in the range of about 385 to about 420.degree. C. The
oil/water mass mix ratio of the mixer 130 is in the range of about
1:0.5 to about 1:3.
[0069] The combined stream 104 is fed to a reactor 140. The
combined stream 104 has a composition as shown in TABLES 1 & 2.
As described in more detail above, the reactor 140 may include, but
is not limited to, a reactor which is equipped with a means for
collecting reaction products (syncrude, water, and gases), and a
section, preferably at the bottom, where any metal containing
compounds or solids (the "dreg stream") may accumulate.
[0070] The reactants in the combined stream 104 are allowed to
react under temperature and pressure conditions of supercritical
water, for a residence time sufficient to allow upgrading reactions
to occur.
[0071] The operating temperature of the reactor 140 is in the range
of about 374.degree. C. to about 1000.degree. C. The operating
pressure of the reactor 140 is in the range of about 3205 to about
10000 psia. The oil/water mass ratio is in the range of about 1:0.1
to a about 1:10. The residence time of the reactor is in the range
of about 1 min to 6 hrs.
[0072] A reactants product stream 105 is cooled and fed to a
separator 150. The reactants product stream 105 has a composition
as shown in TABLES 1 & 2. As described in more detail above,
the cooling may be conducted in a heat exchanger unit that
includes, but is not limited to, a shell and tube heat exchanger
and a plate heat exchanger. Water is cross heat exchanged with the
reactants product stream 105. Due to this heat exchange, the water
is vaporized into a superheated steam that may be integrated and
used in a Steam Assisted Gravity Drainage (SAGD) process in an oil
field.
[0073] As described in more detail above, the separator 150 may
include, but is not limited to, one or more two-phase separators,
three-phase separators, or other known gas-oil-water separation
devices.
[0074] The reactants product stream 105 is separated into a gas
stream 107, a syncrude stream 106, and an effluent water stream
108.
[0075] The operating pressure of the separator 150 is in the range
of about 150 to 3500 psia. The operating temperature of the
separator 150 is in the range of about 50 to 300.degree. C.
[0076] The syncrude stream 106 is fed to a separator 160. The
syncrude stream 106 has a composition as shown in TABLES 1 & 2.
As described in more detail above, the separator 160 may include,
but is not limited to, a packed or trayed-type distillation column
equipped with a reboiler and condenser, a refluxed column with live
steam injection at the bottom, or a vacuum distillation column. The
operating pressure of the separator 160 is in the range of about 1
to about 50 psia. The operating temperature of the overhead
condenser is in the range of about 40 to about 90.degree. C.
[0077] A portion of the overheads diluent stream 109, 111 is
combined with a bottoms syncrude stream 110 at a weight percentage
in the range of about 0 to about 30%. A combined syncrude stream
112 is then fed to further downstream processes or to storage for
further transport.
[0078] The overheads diluent stream 109 is also recycled (stream
113) and fed to a dregs processor 170. A dreg stream 114 is also
fed to the dregs processor 170. The dreg stream 114 has a
composition as shown in TABLES 1 and 2. As described in more detail
above, the dregs processor 170 may include, but is not limited to,
a dregs washer, a mixer-settler, and a solids leaching unit. The
recycle diluent stream 113 from the separator 160 may be used to
extract hydrocarbons from the dregs stream 114 in the dregs washer.
The operating pressure of the dregs processor 170 is in the range
of about 15 to 500 psia. The operating temperature of the dregs
processor 170 is in the range of about 25 to 200.degree. C.
[0079] Although not shown in the figure, the recycle stream 113 may
also be fed directly back into the heavy hydrocarbon feed stream
101. This recycled diluent lowers the density of the heavy
hydrocarbon stream 101 from about 5 to 10 to about 11 to 16 API.
The combining of the diluent also allows for a reduction in the
amount of the water feed stream 103.
[0080] A solid dregs stream 115 and a wet dregs stream 116 is
output from the dregs processor 170. The wet dregs stream 116 is
recycled back to the heavy hydrocarbon feed stream 101 to form 102,
at a percentage in the range of about 50 to 100%. The remaining
portion of the wet dregs stream may be combined with the syncrude
product 112, used for fuel, or sent off to storage and
transportation as a separate product stream.
[0081] In the tables below, two oil assays (one for the feed and
one for the syncrude) are modeled using a set of hydrocarbon
pseudocomponents. The notation, Blend 1 refers to the feed while
Blend 2 refers to the product. The notation Blend 2 (170 to
265.degree. C.) means that the group of components in Blend 2 have
a boiling point range of 170 to 265.degree. C. Non-HC gases refers
to H.sub.2, H.sub.2S, CO.sub.2, N.sub.2, O.sub.2, and NH.sub.3.
HC-Gases may include methane, ethane, propane, butane, pentane,
cyclopentane, cyclohexane, and benzene. Oxygenates include phenol,
heptanoic acid, and catechol.
[0082] TABLE 1 summarizes only the major streams--some intermediate
heat exchange steps, pumping steps, internal recycle streams, and
offsite facilities are not shown.
TABLE-US-00001 TABLE 1 Summary of Major Streams Only (Compositions
in mass %) Stream Non HC BLND1 BLND1 BLND1 BLND 1 BLND 1 BLND 2
BLND 2 BLND 2 BLND 2 No HC Gases 203 to 433 to 654 to 880 to 1101
to 170 to 275 to 383 to 494 to (FIG. 1) H2O Gases (C1-C6) Oxygenate
421 C 649 C 875 C 1096 C 1217 C 265 C 375 C 485 C 634 C 101 <1.0
0 0 0 28.9 35.4 17.6 11.7 6.35 0 0 0 0 102 0.01 0.006 0.226 0.214
24.3 29.8 14.8 9.8 5.3 15.2 0.1 0 0 103 99.4 0.05 0.01 0.55 0 0 0 0
0 0 0 0 0 104 66.4 0.04 0.08 0.44 8.1 9.9 4.9 3.3 1.8 5.0 0.10 0 0
105 67.1 0.52 0.45 0.61 0 0 0 0 0 8.3 8.1 9.2 4.9 106 0.17 0.03 0.4
0.36 0 0 0 0 0 26 28 29.3 15.7 107 3 57.1 37.8 0.23 0 0 0 0 0 1.8 0
0 0 108 99.3 0 0 0.7 0 0 0 0 0 0 0 0 0 109 0.07 0.037 1.4 1.3 0 0 0
0 0 95.2 1.9 0 0 110 0.076 0 0 0 0 0 0 0 0 3.9 36.4 38.8 20.8 111
0.07 0.037 1.4 1.3 0 0 0 0 0 95.2 1.9 0 0 112 0.076 0 0.13 0.13 0 0
0 0 0 12.2 33.3 35.2 18.9 113 0.07 0.037 1.4 1.3 0 0 0 0 0 95.2 1.9
0 0 114 0 0 0 0 28.9 35.4 17.6 11.7 6.4 0 0 0 0 115 N/A N/A N/A N/A
N/A N/A N/A N/A N/A N/A N/A N/A N/A 116 0.06 0.03 1.2 1.1 $ 5.7 2.8
1.9 1.0 79.9 1.6 0 0
TABLE-US-00002 TABLE 2 Summary of Major Streams Only Stream No.
Flowrate Pressure Temp (FIG. 1) (lb/hr) (psia) (.degree. C.) 101
4.43e5 20 90 102 5.47e5 3550 343 103 1.1e6 3600 405 104 1.65e6 3500
393 105 1.63e6 3500 393 106 5.12e5 180 156 107 1.35e4 175 40 108
2.74e5 175 40 109 1.24e5 25 50 110 3.87e5 30 280 111 3.68e4 25 50
112 4.26e5 25 50 113 8.72e4 25 50 114 1.77e4 20 200 115 4.9e3 20 50
116 1.0e5 20 76
OTHER EMBODIMENT
[0083] In another embodiment of the invention illustrated in FIG.
2, a heavy hydrocarbon feed stream 201 and a water feed stream 203,
having conditions as shown in TABLE 3 (Simulated Example Data), are
fed to a mixer 230. As described in more detail above, the mixer
may include, but is not limited to, static mixers, spray nozzles,
and sonic or ultrasonic agitation. The heavy hydrocarbon feed
stream 201 and the water feed stream 203 are mixed so that a
combined stream 204 will reach supercritical water conditions. The
operating pressure of the mixer 230 is in the range of about 3250
to about 3600 psia. The operating temperature of the mixer 230 is
in the range of about 385 to about 420.degree. C. The oil/water
mass mix ratio of the mixer 230 is in the range of about 1:0.5 to
about 1:3.
[0084] The combined stream 204 is fed to a reactor 240. The
combined stream 204 has conditions as shown in TABLE 3. As
described in more detail above, the reactor 240 may include, but is
not limited to, a reactor which is equipped with a means for
collecting reaction products (syncrude, water, and gases), and a
section, preferably at the bottom, where any metal containing
compounds or solids (the "dreg stream") may accumulate.
[0085] The reactants in the combined stream 204 are allowed to
react under temperature and pressure conditions of supercritical
water, for a residence time sufficient to allow upgrading reactions
to occur.
[0086] The operating temperature of the reactor 240 is in the range
of about 374.degree. C. to about 1000.degree. C. The operating
pressure of the reactor 240 is in the range of about 3205 to about
10000 psia. The oil/water volume ratio is in the range of about
1:0.1 to a about 1:10. The residence time of the reactor is in the
range of about 1 min to 6 hrs.
[0087] A reactants product stream 205 is cooled and fed to a
separator 250. The reactants product stream 205 has flow conditions
as shown in TABLE 3. The cooling may be conducted in a heat
exchanger unit that includes, but is not limited to, a shell and
tube heat exchanger and a plate heat exchanger. Water is cross heat
exchanged with the reactants product stream 205. Due to this heat
exchange, the water is vaporized into a superheated steam that may
be integrated and used in a Steam Assisted Gravity Drainage (SAGD)
process in an oil field.
[0088] As described in more detail above, the separator 250 may
include, but is not limited to, one or more two-phase separators,
three-phase separators, or other known gas-oil-water separation
devices.
[0089] The reactants product stream 205 is separated into a gas
stream 206, a syncrude stream 208, and an effluent water stream
207.
[0090] The operating temperature of the separator 250 is in the
range of about 50 to 300.degree. C. The operating pressure of the
separator 250 is in the range of about 150 to 3500 psia.
[0091] The syncrude stream 208 is fed to a separator 260. The
syncrude stream 208 has conditions as shown in TABLE 3. The
separator 260 may include, but is not limited to, a packed or
trayed-type distillation column equipped with a reboiler and
condenser, a refluxed absorber equipped with live steam injection
at the bottoms, or a vacuum distillation column. The operating
pressure of the separator 260 is in the range of about 1 to about
50 psia. The operating temperature of the overhead condenser is in
the range of about 40 to about 90.degree. C.
[0092] A portion of an overhead diluent stream 209, 211 is combined
with a bottoms syncrude stream 210 at a weight percentage in the
range of about 0 to 30%. A combined syncrude stream 212 is then fed
to further downstream processes or to storage and eventual
transportation.
[0093] A portion of the overheads diluent stream 209 is also
recycled (stream 213) and combined with the heavy hydrocarbon feed
201, and output as stream 202. This diluent lowers the density of
the heavy hydrocarbon stream from about 5 to 10 API to a range of
about 11 to 16 API. The combining of the diluent also allows for a
reduction in the amount of the water feed stream 203.
[0094] A dreg stream 214 is fed to a mixer 270. As described in
more detail above, the mixer may include, but is not limited to,
static mixers, spray nozzles, and sonic or ultrasonic agitation.
The dreg stream 214 and a water feed stream 215 are mixed so that a
combined stream 216 will reach supercritical water conditions. The
operating pressure of the mixer 270 is in the range of about 3250
to about 3600 psia. The operating temperature of the mixer 270 is
in the range of about 385 to about 420.degree. C. The oil/water
mass mix ratio of the mixer 270 is in the range of about 1:1 to
about 1:10.
[0095] The combined stream 216 is fed to a reactor 280. The
combined stream 216 has conditions as shown in TABLE 3. As
described in more detail above, the reactor 280 may include, but is
not limited to, a reactor which is equipped with a means for
collecting reaction products (hydrocarbon fraction, water, and
gases), and a section, preferably at the bottom, where any metal
containing compounds or solids (the "non-hydrocarbon fraction") may
accumulate.
[0096] The reactants in the combined stream 216 are allowed to
react under temperature and pressure conditions of supercritical
water, for a residence time sufficient to allow upgrading reactions
to occur.
[0097] The operating temperature of the reactor 280 is in the range
of about 374.degree. C. to about 1000.degree. C. The operating
pressure of the reactor 280 is in the range of about 3205 to about
10000 psia. The oil/water volume ratio is in the range of about
1:0.1 to a about 1:10. The residence time of the reactor is in the
range of about 1 min to 6 hrs.
[0098] A reactants product stream 218 is recycled back to stream
202. The reactants product stream also includes converted and
unconverted hydrocarbons that are extracted in the reactor 280. The
reactants product stream 218 has conditions as shown in TABLE
3.
[0099] This recycling allows for a number of benefits: (1) the raw
crude feed (stream 201) is diluted and made less viscous and less
dense, which makes mixing and reaction easier, and (2) reaction
product (stream 208) is also diluted with lower-density material,
which facilitates eventual separation of hydrocarbons from water in
the separator 250.
[0100] Another dreg stream 217 is output from the bottom of the
reactor 280. The dreg stream 217 includes hydrocarbon solids and
metal-containing compounds.
[0101] In TABLE 3, flowrates are reported in mbpd, which means
thousands of barrels/day at standard liquid conditions. TABLE 3
summarizes only the major streams--some intermediate heat exchange
steps, pumping steps, internal recycle streams, and offsite
facilities are not shown.
TABLE-US-00003 TABLE 3 Summary of Major Streams Only Stream No.
Flowrate Pressure Temp (FIG. 2) (mbpd) (psia) (.degree. C.) 201 30
3500 87 202 38.7 3500 83 203 79 3500 405 204 118 3500 393 205 126
3410 150 206 6.2 3410 150 207 114 3410 150 208 41.3 3410 150 209
12.4 115 52 210 27 115 50 211 3.7 105 52 212 31 105 50 213 8.7 105
50 214 1.2 3500 200 215 2.4 3500 390 216 13.4 3490 388 217 13.4
3490 388 218 1.2 100 80
* * * * *