U.S. patent application number 11/966852 was filed with the patent office on 2009-07-02 for simultaneous metal, sulfur and nitrogen removal using supercritical water.
This patent application is currently assigned to Chevron U.S.A. Inc.. Invention is credited to Zunqing He, Lin Li.
Application Number | 20090166262 11/966852 |
Document ID | / |
Family ID | 40796818 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090166262 |
Kind Code |
A1 |
He; Zunqing ; et
al. |
July 2, 2009 |
SIMULTANEOUS METAL, SULFUR AND NITROGEN REMOVAL USING SUPERCRITICAL
WATER
Abstract
A process for removing metals, sulfur and nitrogen in the
upgrading of hydrocarbons comprising: mixing hydrocarbons
containing metals, sulfur and nitrogen 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 while maintaining an effective
amount of metals, derived from the hydrocarbon undergoing
upgrading, in the reaction zone to catalyze the upgrading
reactions; and recovering upgraded hydrocarbons having a lower
concentration of metals, sulfur and nitrogen than the hydrocarbons
before reaction is disclosed.
Inventors: |
He; Zunqing; (San Rafael,
CA) ; Li; Lin; (Albany, CA) |
Correspondence
Address: |
CHEVRON CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
Chevron U.S.A. Inc.
|
Family ID: |
40796818 |
Appl. No.: |
11/966852 |
Filed: |
December 28, 2007 |
Current U.S.
Class: |
208/208R ;
208/251R; 208/254R |
Current CPC
Class: |
C10G 2300/1011 20130101;
C10L 1/026 20130101; C10G 31/08 20130101; Y02P 30/20 20151101 |
Class at
Publication: |
208/208.R ;
208/251.R; 208/254.R |
International
Class: |
C10G 45/00 20060101
C10G045/00 |
Claims
1. A process for removing metals, sulfur and nitrogen in the
upgrading of hydrocarbons comprising: (a) mixing hydrocarbons
containing metals, sulfur and nitrogen 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; (b)
passing the mixture to a reaction zone; (c) 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 while maintaining
an effective amount of metals, derived from the hydrocarbon
undergoing upgrading, in the reaction zone to catalyze the
upgrading reactions; and (d) recovering upgraded hydrocarbons
having a lower concentration of metals, sulfur and nitrogen than
the hydrocarbons of step (a).
2. A process according to claim 1, wherein the hydrocarbons are
heavy hydrocarbons selected from the group consisting of whole
heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon
fractions obtained from crude petroleum oils, heavy vacuum gas
oils, vacuum residuum, petroleum tar, coal tar and their
mixtures.
3. A process according to claim 1, wherein the fluid comprising
water enters the mixing zone at a temperature sufficiently higher
than the critical temperature of water so as to cause the resulting
mixture to have a temperature higher than the critical temperature
of water.
4. A process according to claim 3, wherein the temperature of the
fluid comprising water is from 400.degree. C. to 600.degree. C.
5. A process according to claim 1, wherein the hydrocarbons in step
(a) are at a temperature of from 100.degree. C. to 200.degree.
C.
6. A process according to claim 1, wherein the supercritical water
conditions include a temperature from 374.degree. C. to
1000.degree. C., a pressure from 3,205 psia to 10,000 psia an
oil/water volume ratio from 1:0.1 to 1:5 and where the residence
time is from 1 minute to 6 hours.
7. A process according to claim 1, wherein the supercritical water
conditions include a temperature from 374.degree. C. to 600.degree.
C., a pressure from 3,205 psia to 7,200 psia, an oil/water volume
ratio from 1:0.5 to 1:3 and where the residence time is from 8
minutes to 2 hours.
8. A process according to claim 1, wherein the supercritical water
conditions include a temperature from 374.degree. C. to 400.degree.
C. a pressure from 3,205 psia to 4,000 psia, an oil/water volume
ratio from 1:1 to 1:2 and where the residence time is from 10 to 40
minutes.
9. A process according to claim 1, wherein the mixture in the
reaction zone is reacted in the absence of any externally supplied
catalyst or promoter.
10. A process according to claim 1, further comprising the step of
heating the mixture formed in step (a) to a temperature higher than
the supercritical temperature of water before passing the mixture
to the reaction zone.
11. A process for removing metals and sulfur in the upgrading of
hydrocarbons comprising: (a) mixing hydrocarbons containing metals
and sulfur with a fluid comprising water having a temperature
higher than the critical temperature of water in a mixing zone to
form a mixture having a temperature higher than the critical
temperature of water; (b) passing the mixture to a reaction zone;
(c) 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 including
demetalation and desulfurization to occur while maintaining an
effective amount of metals, derived from the hydrocarbon undergoing
upgrading, in the reaction zone to catalyze desulfurization
reactions; and (d) recovering upgraded hydrocarbons having a lower
concentration of metals and sulfur than the hydrocarbons of step
(a)
12. A process according to claim 11, wherein the hydrocarbons are
heavy hydrocarbons selected from the group consisting of whole
heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon
fractions obtained from crude petroleum oils, heavy vacuum gas
oils, vacuum residuum, petroleum tar, coal tar and their
mixtures
13. A process according to claim 11, wherein the fluid comprising
water enters the mixing zone at a temperature sufficiently higher
than the critical temperature of water so as to cause the resulting
mixture to have a temperature higher than the critical temperature
of water.
14. A process according to claim 13, wherein the temperature of the
fluid comprising water is from 400.degree. C. to 600.degree. C.
15. A process according to claim 11, wherein the heavy hydrocarbons
in step (a) are at a temperature of from 100.degree. C. to
200.degree. C.
16. A process according to claim 10, wherein the supercritical
water conditions include a temperature from 374.degree. C. to
1000.degree. C., a pressure from 3,205 psia to 10,000 psia an
oil/water volume ratio from 1:0.1 to 1:5 and where the residence
time is from 1 minute to 6 hours.
17. A process according to claim 10, wherein the supercritical
water conditions include a temperature from 374.degree. C. to
600.degree. C., a pressure from 3,205 psia to 7,200 psia, an
oil/water volume ratio from 1:0.5 to 1:3 and where the residence
time is from 8 minutes to 2 hours.
18. A process according to claim 10, wherein the supercritical
water conditions include a temperature from 374.degree. C. to
400.degree. C., a pressure from 3,205 psia to 4,000 psia, an
oil/water volume ratio from 1:1 to 1:2 and where the residence time
is from 10 to 40 minutes.
19. A process according to claim 10, further comprising the step of
heating the mixture formed in step (a) to a temperature higher than
the critical temperature of water before passing the mixture to the
reaction zone.
20. A process for removing metals and sulfur in the upgrading of
hydrocarbons comprising: (a) mixing hydrocarbons containing metals
and sulfur 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; (b) passing the mixture to a reaction zone; (c)
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 including
demetalation and desulfurization to occur while maintaining an
effective amount of metals, derived from the hydrocarbon undergoing
upgrading, in the reaction zone to catalyze desulfurization
reactions; (d) separating a dreg stream containing metals from the
reaction product; (e) passing at least a portion of the dreg stream
to the reaction zone; and (g) recovering upgraded hydrocarbons
having a lower concentration of metals and sulfur than the
hydrocarbons of step (a).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a process for simultaneous
removal of metals, sulfur and nitrogen from heavy oil using
supercritical water.
BACKGROUND OF THE INVENTION
[0002] Heavy oil typically contains high concentration of sulfur,
metals and nitrogen. Such contaminants have very negative effects
on the catalysts and equipment used in many processes for further
refining to produce high value products. Hydroprocessing is
currently the process of choice to remove metal and sulfur from
heavy oil. Hydrotreating process typically takes place in a trickle
bed or fixed-bed reactor using expensive catalyst such as Mo and
requires the use, of high pressure hydrogen which becomes more and
more expensive. Hydrogen-addition processes such as hydrotreating
or hydrocracking require significant investments in capital and
infrastructure. 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.
Therefore there is a need for improved methods/processes for heavy
oil treatment to remove sulfur and metal.
[0003] One alternative to hydrotreating of heavy oil to remove
sulfur and metals is to use supercritical water. However, previous
processes use either catalyst or processing gas (reducing or
oxidizing gas) or both to achieve simultaneous removal of sulfur
and metal. Without externally supplied catalyst or hydrogen, the
contaminate removal rate was not satisfactory.
[0004] U.S. Pat. Nos. 4,594,141; 4,483,761; 4,557,820; and
4,559,127 relate to the upgrading of heavy hydrocarbons using
supercritical water to reduce sulfur, nitrogen and metals in the
products The processes disclose use added olefin or halide
components.
[0005] U.S. Pat. Nos. 3,948,754; 3,948,755 and 3,960,706 relate to
a process using supercritical water for metal and sulfur removal
without external supply of hydrogen using an externally supplied
sulfur and nitrogen resistant catalyst.
[0006] U.S. Pat. No. 5,611,915 relates to a process to remove
sulfur and nitrogen components using supercritical water using high
pressure CO.
[0007] U.S. Patent Application 200310168381, U.S. Patent
Application 2005/0040081 and U.S. Patent Application 200510072137
relate to a process and apparatus for treating heavy oil in such a
way that vanadium contained in heavy oil is isolated during
treatment with supercritical or subcritical water. Oxidizing agent
is used to achieve metals removal. In addition, vanadium oxide
scavenger is used to remove vanadium oxide formed from oxidation of
vanadium by the oxidizing agent from reformed oils.
[0008] U.S. Pat. Nos. 3,989,618 and 4,005,005 relate to a process
to upgrade heavy hydrocarbons using supercritical water without
external supply of H2 or catalyst.
[0009] U.S. Pat. No. 4,446,012 relates to a process of treating
heavy oil to removes metals and sulfur using sub-critical water
(T=380 to 480 C and P=725 to 2175 psi) in the absence of hydrogen
and catalyst.
[0010] A process according to the present invention overcomes these
disadvantages by using supercritical water to upgrade a heavy
hydrocarbon feedstock into an upgraded hydrocarbon product or
syncrude with highly desirable properties (low sulfur content, low
metals content, lower density (higher API), lower viscosity, lower
residuum content, etc.). The process neither requires external
supply of hydrogen nor must it use catalysts. Further, the process
in the present Invention does not produce an appreciable coke
by-product.
[0011] In comparison with the traditional processes for syncrude
production, advantages that may be obtained by the practice of the
present invention include a high liquid hydrocarbon yield; no need
for externally-supplied hydrogen; no need to provide catalyst;
significant increases in API gravity in the upgraded hydrocarbon
product; significant viscosity reduction in the upgraded
hydrocarbon product; and significant reduction in sulfur, metals,
nitrogen, TAN, and MCR (micro-carbon residue) in the upgraded
hydrocarbon product.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a process for removing
metals, sulfur and nitrogen in the upgrading of hydrocarbons
comprising: mixing hydrocarbons containing metals, sulfur and
nitrogen 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 including
demetalation and desulfurization to occur while maintaining an
effective amount of metals, derived from the hydrocarbon undergoing
upgrading, in the reaction zone to catalyze desulfurization
reactions; and recovering upgraded hydrocarbons having a lower
concentration of metals, sulfur and nitrogen than the hydrocarbons
containing metal and sulfur.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a process flow diagram of an embodiment of the
present invention.
[0014] FIG. 2 is a process flow diagram of another embodiment of
the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present process is related to processes described in
commonly assigned U.S. patent application Ser. Nos. 11/555,048;
11/555,130; 11/555,196; and 11/555,211, all of which were filed on
Oct. 31, 2006 and which are incorporated by reference herein. These
patent applications relate to various aspects of heavy oil
upgrading technology using supercritical water. The present
disclosure also relates to processes using supercritical water to
upgrade hydrocarbons.
[0016] Reactants
[0017] Water and hydrocarbons which contain metals, sulfur and
nitrogen compounds, preferably heavy hydrocarbons are the two
reactants employed in a process according to the present
invention.
[0018] Any heavy hydrocarbon 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.. 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, shale oil, and asphaltenes.
[0019] Water
[0020] 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.
[0021] Mixing
[0022] 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 temperature 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.
[0023] It was found that by avoiding excessive heating of the feed
oil, the formation of byproduct such as solid residues is reduced
significantly. In one embodiment, the heating sequence is designed
so that the temperature and 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.
[0024] FIG. 1 shows an embodiment of a process according to the
invention. Water is heated up to supercritical conditions by Heater
1, then the supercritical water mixed with heavy oil feed in the
mixer. The temperature of heavy oil feed can be kept in the range
of about 100.degree. C. to 200.degree. C. to avoid thermal cracking
but still high enough to maintain reasonable pressure drop. In an
embodiment in which after mixing with heavy oil, the temperature of
the water-oil mixture would be lower than critical temperature of
water, Heater 2 is used to raise the temperature of the mixture
stream to above the critical temperature of water. In this
embodiment, the heavy oil is first partially heated up by water,
then the water-oil mixture is heated to supercritical conditions by
the second heater (Heater 2). Where after mixing with heavy oil,
the temperature of the water-oil mixture is higher than the
critical temperature of water, a second heater would not be
used.
[0025] Other methods of mixing and heating sequences based on the
above teachings may be used to accomplish these objectives as will
be recognized by those skilled in the art.
[0026] Reaction Conditions
[0027] 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.
[0028] "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
and water-gas-shift reaction.
[0029] 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 metals or solids (the "dreg stream") may
accumulate.
[0030] 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 400.degree. C., a pressure from
3,205 (the critical pressure of water) to 10,000 psia, preferably
from 3,205 psia to 7,200 psia and most preferably from 3,205 to
4,000 psia, an oil/water volume ratio from 1:0.1 to 1:10,
preferably from 1:0.5 to 1:3 and most preferably about 1:1 to
1:2.
[0031] 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 10 to
40 minutes.
[0032] The present process includes the feature of maintaining an
effective amount of metals, derived from the hydrocarbon undergoing
upgrading, in the reaction zone to catalyze desulfurization
reactions. Since the metals removed from heavy oil will serve as
catalyst for sulfur removal, it is important to maintain metal
concentrations inside the reactor. With reference to the embodiment
shown in FIG. 1, such requirement is met by using a CSTR
(continuous stirred tank reactor) type reactor. For CSTR metals
formed through metals removal reactions are well mixed with feed
stream and catalyze sulfur removal reactions, and therefore high
removal rate of both metal and sulfur can be achieved.
[0033] FIG. 2 shows another method of maintaining an effective
amount of metal in the reaction zone. In this embodiment part of
dreg stream which contains high concentration of metals is recycled
back to maintain adequate metal concentration in the reactor. The
metal concentration inside the reactor can be controlled by
adjusting recycle ratio. Such recycle strategy can also be used to
control metal concentration when a CSTR is used. The dreg stream
may either be withdrawn from anywhere it forms, for example from
the reactor or from a high pressure separator shown in FIG. 2.
[0034] Reaction Product Separation
[0035] After the reaction has progressed sufficiently, a single
phase reaction product is withdrawn from the reaction zone, cooled,
and 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.
[0036] 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.
[0037] 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.
[0038] 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 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. For
continuous operations such as those shown in FIG. 1 and FIG. 2, oil
feed will be heated up very quickly by supercritical water, and a
preferred means for achieving simultaneous removal of metals,
sulfur and nitrogen is using a reactor with backmixing behavior or
to recycle some of the reactor bottoms (dreg stream) so that the
metals removed from the feed oil will serve as catalyst for sulfur
removal reactions.
[0039] 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:
[0040] Thermal Cracking: C.sub.xH.sub.y.fwdarw.lighter
hydrocarbons
[0041] Steam Reforming:
C.sub.xH.sub.y+2xH.sub.2O=xCO.sub.2+(2x+y/2)H.sub.2
[0042] Water-Gas-Shift: CO+H.sub.2O=CO.sub.2+H.sub.2
[0043] Demetalization:
C.sub.xH.sub.yNi.sub.w+H.sub.2O/H.sub.2.fwdarw.NiO/Ni(OH).sub.2+lighter
hydrocarbons
[0044] Desulfurization:
C.sub.xH.sub.yS.sub.z+H.sub.2O/H.sub.2=H.sub.2S+lighter
hydrocarbons
[0045] The exact pathway may depend on the reactor operating
conditions (temperature, pressure, O/W volume ratio), reactor
design (mode of contact/mixing, sequence of heating), and the
hydrocarbon feedstock.
[0046] The following Examples 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.
EXAMPLE 1
Experimental Process Description
[0047] A bomb reactor was loaded with a water and a heavy oil feed
with API=12.8, which was a heavy crude oil which was diluted with a
diluent hydrocarbon at a ratio of 5:1 (20 vol % of diluent). The
reactor was immersed in a sand bath at reaction temperature so the
temperature inside the reactor was quickly raised to
.about.400.degree. C., typically in 3 to 5 minutes. The reaction
time was 30 minutes, and after reaction the reactor was quickly
cooled down. The upgraded oil product and water were then recovered
from the bomb reactor.
[0048] The properties of the heavy crude feed were as follows: 12.8
API gravity at 60/60; 1329 CST viscosity @40.degree. C.; 13.04 wt %
MCRT; 3.54 wt % sulfur; 0.56 wt % nitrogen; 3.05 mg KOH/gm acid
number; 1.41 wt % water; 371 ppm Vanadium; and 86 ppm Nickel.
[0049] After the super critical water treatment upgraded product
(syncrude) had the following properties: 19.2 API gravity at 60/60;
3.15 wt % MCRT; 0.54 wt % sulfur; 0.21 wt % nitrogen; 5.16 ppm
Vanadium; and 1.09 ppm Nickel. Substantial reductions in metals and
sulfur were observed, with simultaneous increase in the API gravity
and a significant decrease in the viscosity of the original crude
oil feedstock.
EXAMPLE 2
[0050] The following procedure was performed using a continuous
system. The feed oil was heated to 130.degree. C. before entering a
mixer. The heated crude was injected into a stream of supercritical
water at temperature of 400.degree. C. The water to oil ratio
(volume at room temperature) was 3:1. The oil-supercritical water
mixture was then injected into a reactor at temperature of
400.degree. C. and pressure of 3400 psig. The upgraded product,
which formed a homogeneous phase with supercritical water, was
withdrawn from the top of the reactor and send to high pressure
separator which was operated at the same pressure but lower
temperature to achieve oil-water separation. The dreg stream was
removed from reactor bottom.
[0051] The properties of the feed crude in Example 2 were as
follows: 8 API gravity at 60/60; 65689 CST viscosity @40.degree.
C.;. 15.7 wt % MCRT; 4.17 wt % sulfur; 0.68 wt % nitrogen; 5.8 mg
KOH/gm acid number; 435 ppm Vanadium; and 104 ppm Nickel.
[0052] After the super critical water treatment upgraded product
(syncrude) had the following properties: 20.5 API gravity at 60/60;
10.9 CST viscosity @400.degree. C., 2.2 wt % MCRT; 3.17 wt %
sulfur; 0.29 wt % nitrogen; 40.9 ppm Vanadium; and 5.9 ppm
Nickel.
EXAMPLE 3
[0053] The procedure of Example 2 was repeated except that the
properties of the feed crude were as follows: 8 API gravity at
60/60; 20,400 CST viscosity @40.degree. C.; 13 wt % MCRT; 5 wt %
sulfur; 0.48 wt % nitrogen; 3.8 mg KOH/gm acid number; 215 ppm
Vanadium; and 80 ppm Nickel.
[0054] After the super critical water treatment upgraded product
(syncrude) had the following properties: 18 API gravity at 60/60;
21 CST viscosity @40.degree. C. 3 wt % MCRT; 4 wt % sulfur; 0.27 wt
% nitrogen; 41 ppm Vanadium; and 8 ppm Nickel.
[0055] For Examples 2 and 3, substantial reductions in metals,
nitrogen and sulfur were observed, with simultaneous increase in
the API gravity and a significant decrease in the viscosity of the
original crude oil feedstock.
[0056] There are numerous variations on the present invention which
are possible in light of the teachings,and supporting examples
described herein. It is therefore understood that within the scope
of the following claims, the invention may be practiced otherwise
than as specifically described or exemplified herein.
* * * * *