Note: Descriptions are shown in the official language in which they were submitted.
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PARTIAL UPGRADING PROCESS FOR HEAVY OIL AND
BITUMEN
FIELD OF THE INVENTION
[0001] The present invention relates to modifications of bitumen and heavy oil
upgrading processes to synthesize synthetic crude oil and other valuable
hydrocarbon
byproducts operations in an efficient manner.
BACKGROUND OF THE INVENTION
[0002] It is well established that certain forms of hydrocarbons require
upgrading in
order to either transport them or enhance value for sale. Further, refineries
are not suited to
processing heavy oil, bitumen etc. and thus the viscosity, density and
impurity content,
such as heavy metals, sulfur and nitrogen, present in such heavy materials
must be altered
to permit refining. Upgrading is primarily focussed upon reducing viscosity,
sulfur, metals,
and asphaltene content in the bitumen.
[0003] One of the problems with heavy oil and bitumen upgrading is that the
asphaltenes
and the heavy fraction must be removed or modified to create value and product
yield.
Typical upgraders exacerbate the problem by the formation of petcoke or
residuum which
results in undesirable waste material. This material, since it cannot be
easily converted by
conventional methods, is commonly removed from the process, reducing the
overall yield
of valuable hydrocarbon material from the upgrading process.
[0004] The Fischer-Tropsch process has found significant utility in
hydrocarbon
synthesis procedures and fuel synthesis. The process has been used for decades
to assist in
the formulation of hydrocarbons from several materials such as coal, residuum,
petcoke,
and biomass. in the last several years, the conversion of alternate energy
resources has
become of great interest, given the escalating environmental concerns
regarding pollution,
the decline of world conventional hydrocarbon resources, and the increasing
concern over
tailings pond management, together with the increasing costs to extract,
upgrade and refine
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the heavy hydrocarbon resources. The major producers in the area of synthetic
fuels have
expanded the art significantly in this technological area with a number of
patented
advances and pending applications in the form of publications. Applicant's co-
pending
United States Application Serial No. 13/024,925, teaches a fuel synthesis
protocol.
[0005] Examples of recent advances that have been made in this area of
technology
includes the features taught in United States Patent No. 6,958,363, issued to
Espinoza, et
al., October 25, 2005, Bayle et al., in United States Patent No. 7,214,720,
issued May 8,
2007, United States Patent No. 6,696,501, issued February 24, 2004, to Sehanke
et al.
[0006] In respect of other progress that has been made in this field of
technology, the art
is replete with significant advances in, not only gasification of solid carbon
feeds, but also
methodology for the preparation of syngas, management of hydrogen and carbon
monoxide in a XTL plant, the Fischer-Tropsch reactors management of hydrogen,
and the
conversion of carbon based feedstock into hydrocarbon liquid transportation
fuels, inter
alia. The following is a representative list of other such references. This
includes: US
Patent Nos. 7,776,114; 6,765,025; 6,512,018; 6,147,126; 6,133,328; 7,855,235;
7,846,979;
6,147,126; 7,004,985; 6,048,449; 7,208,530; 6,730,285; 6,872,753, as well as
United
States Patent Application Publication Nos. US2010/0113624; US2004/0181313;
US2010/0036181; US2010/0216898; US2008/0021122; US2008/0115415; and
US2010/0000153.
[0007] The Fischer-Tropsch (FT) process has several significant benefits when
applied
to a bitumen upgrader process, one benefit being that it is able to convert
previously
generated petcoke and residuum to valuable, high quality synthetic crude oil
(SCO) with
notably increased paraffinic content. A further significant benefit is that
the raw bitumen
yield to SCO is near or greater than 100%, a 20% yield increase relative to
certain current
upgrader processes. Another benefit is that there is no petcoke and residuum
waste product
to impact the environment thus improving overall bitumen resource utilization.
[0008] A further benefit of the application of the FT process to a bitumen
upgrader is
that the FT byproducts can be partially and fully blended with the distilled
or separated
fractions of the bitumen or heavy oil feed stream to formulate a unique
bottomless partially
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upgraded synthetic crude oil (SCO) strategically blended for efficient
transport and further
processing in downstream refineries.The overall benefit is significant
reduction in facility
GHG emissions and 100% conversion of the bitumen or heavy oil resource without
the
formation of wasteful byproducts.
100091 A further benefit of the application of the FT process to a bitumen
upgrader is
that a sweet, highly paraffinic and high cetane content synthetic crude oil
(SCO) is
produced. More specifically, beneficial byproducts of the FT process such as
paraffinic
naphtha and FT vapours (such as methane and liquid petroleum gases (LPG)),
have
particular value within the bitumen upgrader process and upstream unit
operations. FT
vapours, virtually free from sulfur compounds can be used as upgrader fuel or
as feedstock
for hydrogen generation to offset the requirement for natural gas. FT naphtha,
primarily
paraffinic in nature, can also be used in the generation of hydrogen, but
further, due to its
unique paraffinic nature, it can also be used as an efficient deasphalting
solvent not readily
available from current upgrader operations.
[0010] It has also been well documented that the use of FT paraffinic naphtha
as a
solvent for an oil sands froth unit improves the operation and efficacy of
fine tailings and
water removal at a reduced diluent to bitumen (D/B) ratio and relatively low
vapour
pressure. This has significant advantages in terms of lowering the size and
cost of
expensive separators and settlers and increasing their separation performance
and capacity
rating. This results in virtually dry bitumen froth feed (<0.5 basic sediment
and water) to
the upgrader, while improving impact on the tailings pond.
Pill Having thus generally discussed the appropriateness of the Fischer-
Tropsch
technique in synthesizing syngas to FT liquids, a discussion of the prior art
and particularly
the art related to the upgrading and gasifying of heavy hydrocarbon feeds
would be useful.
100121 One of the examples in this area of the prior art is the teachings
of United States
Patent No. 7,407,571 issued August 5, 2008, to Rettger et.al. This reference
names Ormat
Industries Ltd. as the Assignee and teaches a process for producing sweet
synthetic crude
oil from a heavy hydrocarbon feed. In the method, the patentees indicate that
heavy
hydrocarbon is upgraded to produce a distillate feed which includes sour
products and high
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carbon byproducts. The high carbon content byproducts are gasified in a
gasifier to
produce a syngas and sour byproducts. The process further hydroprocesses the
sour
products along with hydrogen gas to produce gas and a sweet crude. Hydrogen is
recovered in a recovery unit from the synthetic fuel gas. The process also
indicates that
further hydrogen gas is processed and hydrogen depleted synthetic fuel gas is
also
produced. Further hydrogen gas is supplied to the hydroprocessing unit and a
gasifying
step is conducted in the presence of air or oxygen. The gas mixture is
scrubbed to produce
a sour water and a clean sour gas mixture. The sour gas mixture is
subsequently processed
to produce a sweet synthetic fuel gas and a hydrogen enriched gas mixture from
the
synthetic fuel gas using a membrane. The overall process is quite effective,
however, it
does not take advantage of the conversion of synthesized streams which are
useful for
introduction into the hydroprocessing unit for production of synthetic crude,
the recycling
of unique streams for use in the upgrader, nor is there any teaching
specifically of the
integration of the Fischer-Tropsch process or the recognition of the benefit
to the process
of using a SMR and/or ATR in the process circuit to maximize SCO yields and
reducing
dependence on natural gas.
[00131 Iqbal etal. in United States Patent No. 7,381,320 issued June 3,
2008, teaches a
process for heavy oil and bitumen upgrading. in overview, the process is
capable of
upgrading crude oil from a subterranean reservoir. The process involves
converting
asphaltenes to steam power, fuel gas, or a combination of these for use in
producing heavy
oil or bitumen from a reservoir. A portion of the heavy oil or bitumen are
solvent
deasphalted to form an asphaltene fraction and a deasphalted oil, referred to
in the art as
DAO as a fraction free of asphaltenes and with reduced metals content. The
asphaltene
fraction from the solvent deasphalting is supplied to the asphaltenes
conversion unit and a
feed comprising the DA0 fraction supplied to a reaction zone of a fluid
catalytic cracking
(FCC) unit with an FCC catalyst to capture a portion of the metals from the
DA0 fraction.
A hydrocarbon effluent is recovered from this having a reduced metal content.
Similar to
the process taught in U.S. Patent No. 7,407,571, this process has utility,
however, it limits
the conversion of the otherwise wasteful asphaltene to production of solid
fuel or pellets or
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conversion to syngas for fuel, hydrogen or electric power production. There is
no teaching
specifically integrating the Fischer-Tropsch process.
(0014) In United States Patent No. 7,708,877 issued May 4th, 2010 to
Farshid etal.
there is taught an integrated heavy oil upgrader process and in line hydro
finishing process.
In the process, a hydroconversion slurry reactor system is taught that permits
a catalyst,
unconverted oil and converted oil to circulate in a continuous mixture
throughout a reactor
with no confinement of the mixture. The mixture is partially separated between
the
reactors to remove only the converted oil while allowing unconverted oil in
the slurry
catalyst to continue on to the next sequential reactor where a portion of the
unconverted oil
is converted to a lower boiling point. Additional hydroprocessing occurs in
additional
reactors for full conversion of the oil. The so called fully converted oil is
subsequently
hydrofinished for nearly complete removal of heteroatoms such as sulfur and
nitrogen.
(0015) This document is primarily concerned with hydroconversion of heavy
hydrocarbon, while not being suitable for bitumen upgrading. It also fails to
provide any
teaching regarding the use of Fischer-Tropsch process, usefulness of recycle
streams,
hydrogen generation or other valuable and efficient unit operations critical
to successful
upgrading of raw bitumen.
100161 Calderon e.t.a in United States Patent No. 7,413,647 issued August
19, 2008,
teach a method and apparatus for upgrading bituminous material. The method
involves a
series of four distinct components, namely a fractionator, a heavy gas oil
catalytic treater, a
catalyst regenerator/gasifier and a gas clean up assembly. The patent
indicates that in
practicing the method, the bitumen in liquid form is fed to the fractionator
for primary
separation of fractions with the bulk of the bitumen leaving the bottom of the
fractionator
in the form of a heavy gas oil which is subsequently pumped to the catalytic
treater and
sprayed on a hot catalyst to crack the heavy gas oil, thus releasing
hydrocarbons in the
form of hydrogen rich volatile matter while depositing carbon on the catalyst.
The volatile
matter from the treater is passed to the fractionator where condensable
fractions are
separated from noncondensable hydrogen rich gas. The carbon containing
catalyst from
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the treater is recycled to the regenerator/gasifier and the catalyst, after
being regenerated is
fed hot to the treater.
[0017] The method does not incorporate the particularly valuable Fischer-
Tropsch
process or provide a unit for effecting the Fischer-Tropsch reaction and
further, the method
is limited by the use of the catalyst which would appear to be quite
susceptible to sulfur
damage and from this sense there is no real provision for handling the sulfur
in the
bitumen.
[0018] In United States Patent Application, Publication No. US
2009/0200209,
published August 13, 2009, Sury etal. teach upgrading bitumen in a paraffinic
froth
treatment process. The method involves adding a solvent to a bitumen froth
emulsion to
induce a settling rate of at least a portion of the asphaltenes and mineral
solids present in
the emulsion and results in the generation of the solvent bitumen-froth
mixture. Water
droplets are added to the solvent bitumen-froth mixture to increase the rate
of settling of
the asphaltenes and mineral solids. The focus of the publication is primarily
to deal with
the froth. There is no significant advance in the upgrading of the bitumen.
[0019] A wealth of advantages are derivable from the technology that has been
developed and which is described herein. These are realized in a number of
ways
including:
a) near 100% or greater synthetic crude oil yield from heavy oil or bitumen
without the wasteful production of petcoke or residuum;
b) bottomless partially upgraded synthetic crude oil (SCO) is strategically
formulated for high efficiency transport, including pipelining, eliminates
crude properties that restrict the amount of heavy oil and bitumen that can
be processed in conventional refineries;
c) Maximum utilization of carbon in heavy oil and bitumen to form high
quality synthetic fuels and crude oil, with the significant reduction (greater
than 50%) in GHG from the facility;
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d) the synthetic crude oil (SCO) slate from partial upgrading is higher
quality,
bottomless crude with more paraffinic and less aromatic and heavy gas oil
components, low metals, lower sulfur, lower TAN number and significantly
lower Conrad Carbon (CCR) in the product slate;
e) less natural gas is required to generate hydrogen for upgrading as the FT
naphtha, FT vapours and hydroprocessing vapours can be recycled to
generate a hydrogen rich syngas;
f) pure hydrogen can be generated from the hydrogen rich syngas using
membranes, absorption or pressure swing adsorption units, for use in the
hydroprocessing (hydrocracking, isomerisation, hydrotreating) units;
g) Fischer-Tropsch (FT) liquids are primarily paraffinic in nature improving
the quality and value of SCO product slate;
h) FT naphtha is rarely available in any quantity in current upgraders and
would be very preferentially used for deasphalting vacuum bottoms in a
Solvent Deasphalting Unit (SDA) and in a oil sands Froth Treatment Unit;
and
i) concentrated CO2 is available from the gasifier (XTL) syngas treatment
unit, allowing the upgrader to be a low cost carbon capture ready CO2
source for carbon capture and sequestration (CCS) projects.
[00201 One object of the present invention is to provide an improved heavy
oil and
bitumen upgrading methodology for synthesizing hydrocarbons with a
substantially
increased yield without the production of waste byproducts such as petcoke or
residuum.
100211 A further object of one embodiment of the present invention is to
provide a
partial upgrading process for synthetic crude which obviates all of the
encumbrances
associated with diluent handling, transportation and other logistics typically
commensurate
with currently practiced partial upgrading techniques or dilbit products.
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100221 A further object of one embodiment of the present invention is to
provide for a
process for upgrading heavy oil or bitumen to formulate hydrocarbon
byproducts. The
process comprises:
a) providing a source of heavy oil or bitumen feedstock;
b) treating said feedstock to form a non-distilled bottoms fraction;
c) feeding said bottoms fraction to a syngas generating circuit for
formulating
a hydrogen lean syngas stream via a partial oxidation reaction, and reacting
said syngas in a Fischer-Tropsch reactor to synthesize hydrocarbon
byproducts;
d) removing at least a portion of partially upgraded synthetic crude oil for
transport as a synthesized hydrocarbon byproduct; and
e) adding an external source of hydrogen to said hydrogen lean syngas to
optimize the synthesis of hydrocarbons at least one of which is synthetic
crude oil.
[0023] The partial upgrading protocol also has a number of benefits all of
which have
immediately monetizable and expediency attributes.
10024] Generally speaking, the partial upgrading process is a process to
upgrade heavy
oil or bitumen with density of 15 to 24 API or more perferred 20 API. The
process is
specifically designed to produce synthetic crude oil for pipeline operations,
specifically
with viscosity less than 350 centistokes (0.00035m2S-1) at 15 C and eliminate
the need for
supply of external diluent typically used to reduce viscosity for
transportation.
[0025] Presently, there is insufficient petroleum diluent available to
transport all the
heavy crude oil from Alberta. The alternative is to recover and ship the
diluent back to
Alberta for blending at significant cost impact. The partially upgraded
product is further
specifically formulated to meet the highly preferred crude feedstock
specifications required
by conventional refineries allowing for a premium price for approaching West
Texas
Intermediate(WTI) and Brent value. In addition, the product has properties
which resolve
environmental impact related to pipeline leaks and oil spills during land and
ocean
transport. The unique properties include:
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a) The product meets 20 API density specification and has a viscosity of less
than 350 centistokes (0.00035m2s-1) at 15 C without the addition of
external (30 to 50 volume %) diluent and requirement for return shipment
of diluent. The use of external diluent reduces the pipeline capacity and
increases cost to operate (pumping energy) by more than 30 %;
b) The process coverts 100 wt% of the bitumen or heavy oil feed with at least
50% reduction, more preferred 70 to 80% reduction in greenhouse gases
(GHG) with no waste byproducts such as unconverted residuum or coke
products;
c) The product yield is greater than 108 vol % yield, which is a 38% greater
yield than conventional dilbit process and 26% greater than other
conventional upgrading processes;
d) The product has 30% less sulfur and is the only bottomless product with
greater than 80% of Conrad Carbon (CCR) removed and primarily all
950+F bottoms material removed. Advantageously, this reduces the
residuum and coking load on conventional refineries, eliminates the
undesirable fouling of conventional refineries, and removes greater than
90% of the heavy metals eliminating major cost impact to a refinery, such
as catalyst replacement;
e) The product is compatible with other crude oils as the process does not
involve cracking of the distilled and separated streams and eliminates the
formation of olefin compounds. The product is stable as no asphaltene
compunds can precipitate, as these compounds have substantially been
removed . This eliminates the blending restriction typically reducing the
mixing limits with other crude feedstocks (typically less than 10% heavy oil
or bitumen is permitted in total crude feed);
0 The product has minimal light volatile compounds such as LPG, more
paraffinic components versus aromatics and contains an increased distillate
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component, such as diesel and kerosene. Under spill conditions, the density
of the product will remain below a specific gravity of 1.0, typically 0.90 to
0.93 and always be lighter than water;
g) The product contains increase of distillate diesel component and this
distillate component is much improved to greater than 55 cetane, versus
typical cctane levels less than 35 in conventional dilbit products; and
h) The product process significantly reduces Naphthenic Acid content or TAN
number (typically much less than 3, perferrably less than 1) as the naphthenic
acid
is concentrated in the vacuum bottoms, which is destroyed by gasification
process.
[0026] The present technology mitigates the oversights exemplified in the
prior art
references. Despite the fact that the prior art, in the form of patent
publications, issued
patents, and other academic publications, all recognize the usefulness of a
Fischer-Tropsch
process, steam methane reforming, autothermal reforming, hydrocarbon
upgrading,
synthetic oil formulation, stream recycle, and other processes, the prior art
when taken
individually or when mosaiced is deficient a process that provides the
efficient upgrading
of bitumen and heavy oil in the absence of residuum and/or petcoke generation.
[0027] Synthetic crude oil (SCO) is the output from a bitumen/heavy
oil upgrader facility used in connection with bitumen and heavy oil from
mineable oil
sands and in situ production. It may also refer to shale oil, an output from
an oil shale
pyrolysis. The properties of the synthetic crude depend on the processes used
in the partial
or full upgrading. Typical full upgraded SCO is devoid of sulfur and has an
API gravity of
around 30 to 40, suitable for conventional refinery feedstock. It is also
known as "upgraded
crude". The processes delineated herein are particularly effective for partial
upgrading, full
upgrading or full refining to gasoline, jet fuel and diesel fuel.
Conveniently, the flexibility
of the processes allows for fuel synthesis and synthetic crude oil partial
upgrading within
the same protocol or the partial upgrading as the entire process.
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100281 The present invention amalgamates, in a previously unrecognized
combination, a
series of known unit operations into a much improved synthesis route for a
high yield, high
quality production of synthetic hydrocarbons. Integration of a Fischer-Tropsch
process,
and more specifically the integration of a Fischer-Tropsch process with a
hydrogen rich
syngas generator which uses FT naphtha and/or FT upgrader vapours as primary
fuel in
combination with natural gas, in a steam methane reformer (SMR) and/or an
autothermal
reformer (ATR) results in a superior sweet synthetic crude oil which is
synthesizable in the
absence of petcoke and residuum.
[0029] It was discovered that, by employing a steam methane reformer (SMR) as
a
hydrogen rich syngas generator using Refinery Fuel, Refinery LPG, FT LPG, FT
naphtha
and FT/upgrader vapours, in combination with natural gas, significant results
can be
achieved when blended with the hydrogen lean syngas created by the
gasification of non-
distilled bitumen or heavy oil bottoms. A significant production increase in
middle
distillate synthetic hydrocarbons range is realized. The general reaction is
as follows;
Natural Gas + FT Naphtha(v) + FT Upgrader Vapours + Steam + Heat - CO +
CO2.
PM As is well known to those skilled in the art, steam methane reforming
may be
operated at any suitable conditions to promote the conversion of the
feedstreams, an
example as shown in above equation, to hydrogen H2 and carbon monoxide CO, or
what is
referred to as syngas or specifically as hydrogen rich syngas. Significant
benefits resulted
in a great than 30% increase in middle distillate synthesized hydrocarbon.
Steam and
natural gas is added to optimize the desired ratio of hydrogen to carbon
monoxide to
approximate range of 3:1 to 6:1. A water gas shift reaction (WGS), pressure
swing
adsorption (PSA) or membrane unit can also be added to any portion of the SMR
syngas
circuit to further enrich the hydrogen rich stream and generate a near pure
hydrogen stream
for hydroprocessing use. Generally natural gas, FT Vapours, Refinery Gas or
any other
suitable fuel is used to provide the heat energy for the SMR furnace.
100311 The steam reformer may contain any suitable catalyst, an example of
one or
more catalytically active components such as palladium, platinum, rhodium,
iridium,
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osmium, ruthenium, nickel, chromium, cobalt, cerium, lanthanum, or mixtures
thereof The
catalytically active component may be supported on a ceramic pellet or a
refractory metal
oxide. Other forms will be readily apparent to those skilled.
100321 It was further discovered that employing an autothermal reformer (ATR)
as a
sole hydrogen rich syngas generator or in combination with the SMR or as a
hybrid
combination of an ATR/SMR referred to as a XTR, significant benefits resulted
in a
greater than 200% increase in the FT middle distillate synthetic hydrocarbons.
Feedstreams
for the ATR or XTR consist of FT naphtha, FT vapours, H2 rich upgrader
vapours, CO2,
02 and natural gas.
[0033] Similarly, as is well known to those skilled in the art,
autotherrnal reforming
employs carbon dioxide and oxygen, or steam, in a reaction with light
hydrocarbon gases
like natural gas, FT vapours and upgrader vapours to form syngas. This is an
exothermic
reaction in view of the oxidation procedure. When the autothermal reformer
employs
carbon dioxide, the hydrogen to carbon monoxide ratio produced is 1:1 and when
the
autothermal reformer uses steam, the ratio produced is approximately 2.5:1, or
unusually
as high as 3.5:1.
10034] The reactions that are incorporated in the autothermal reformer are as
follows:
2CH4 + 02 + CO2 + 3C0 + H20 + HEAT.
When steam is employed, the reaction equation is as follows:
4CH4 + 02 + 2H20 -I- HEAT ---> 1 OH2 + 4CO.
[0035] One of the more significant benefits of using the ATR is realized in
the
variability of the hydrogen to carbon monoxide ratio. An additional benefit of
using the
ATR is that external CO2 can be added to reaction to effect a reverse shift
reaction to
create additional carbon monoxide for enhancement of the FT synthesis unit and
reduction
of overall facility GHG emissions. In the instant technology, an ATR may also
be
considered as a hydrogen rich syngas generator, as described previously. It
has been found
that the addition of the ATR operation to the circuit separately or in
combination with the
hydrogen rich syngas generation circuit, shown in the example above as a steam
methane
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reformer (SMR), has a significant effect on the hydrocarbon productivity from
the overall
process. Similarly, a water gas shift reaction (WGS), pressure swing
adsorption (PSA) or
membrane unit can also be added to any portion of the ATR and combined ATR/SMR
or
XTR syngas circuit to further enrich the hydrogen rich stream and generate a
near pure
hydrogen stream for hydroprocessing use.
[0036] The present invention further amalgamates, in a previously unrecognized
combination, a series of known unit operations to integrate the Fischer-
Tropsch process,
using a water gas shift reaction for syngas enrichment resulting in a valuable
sweet
synthetic crude oil which is synthesizable in the absence of petcoke and
residuum.
[0037] Accordingly, a further object of one embodiment of the present
invention is to
provide a process for upgrading heavy oil or bitumen to formulate hydrocarbon
byproducts, comprising:
a) providing a source of bitumen or heavy oil feedstock and distilling said
feedstock to form a separated portion and a non-distilled bottoms fraction;
b) feeding said bottoms fraction to a syngas generating circuit for
formulating
a hydrogen lean syngas stream via a partial oxidation reaction;
c) treating at least a portion of the said hydrogen lean syngas stream to a
water
gas shift (WGS) reaction to generate an optimum Fischer-Tropsch syngas;
and
d) treating said optimum Fischer-Tropsch syngas stream in a Fischer-Tropsch
unit to synthesize hydrocarbon byproducts, at least one of which is blended
with said non-distilled bottoms fraction or said separated portion to form a
partially upgraded synthetic crude oil having an API gravity between 15 and
24.
[0038] In accordance with a further object of one embodiment of the present
invention,
there is provided a method for synthesizing hydrocarbons, comprising:
a) formulating a hydrogen lean syngas stream in a partial oxidation reaction;
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b) catalytically converting said syngas stream to produce hydrocarbon
byproducts for formulating a partially upgraded synthetic crude oil;
c) maintaining said partially upgraded API range of between 15 and 24 absent
the addition of external diluent; and
d) removing at least a portion of said partially upgraded synthetic crude oil
for
transportation.
[0039]
Accordingly, it is another object of one embodiment of the present invention
to
provide the process, wherein the water gas shift reactor (WGS) is replaced by
a hydrogen
rich syngas generator (XTR) selected from the group consisting of a steam
methane
reformer (SMR), autothermal reformer (ATR) or combination thereof.
[0040] A further object of one embodiment of the present invention is to
provide a
process for synthesizing hydrocarbons, comprising the steps of:
(a) formulating a hydrogen rich stream with a syngas generator;
(b) catalytically converting said stream to produce hydrocarbons, containing
at
least naphtha and partially upgraded synthetic crude oil having an API
index between 15 and 24 suitable for transport;
(c) removing said partially upgraded synthetic crude oil;
(d) recycling at least a portion of said naphtha to said syngas generator to
form
an enhanced hydrogen rich stream; and
(e) re-circulating said enhanced hydrogen rich stream from step (d) for
conversion in step (b) to enhance the synthesis of hydrocarbons.
[0041] In accordance with a further aspect of one embodiment of the present
invention,
there is provided a process for converting heavy oil or bitumen to
transportable synthetic
crude oil, comprising:
(a) treating said heavy oil or bitumen in an atmospheric distillation/diluent
recovery unit to create a first stream containing at least straight run
naphtha, light gas oil and liquid petroleum gas (LPG);
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(b) passing a second atmospheric bottoms stream generated from step a) into a
solvent deasphalting unit to formulate a deasphalted oil stream and a
residuum asphaltene stream;
c) passing said residuum asphaltene stream of the deasphalting unit into a
diesel producing circuit having a syngas generator and Fischer-Tropsch
reactor to convert said portion to at least a synthetic diesel; and
d) blending said first stream, deasphalted oil stream and said synthetic
diesel
to form partially upgraded synthetic crude oil.
[0042] In accordance with yet another object of one embodiment of the
present
invention, there is provided a process for converting heavy oil or bitumen to
a
transportable partially upgraded synthetic crude oil, comprising:
a) processing said heavy oil or bitumen with unit operations to produce a
treated stream and a non-distilled stream;
b) foiming syngas from said non-distilled stream and reacting the syngas in a
Fischer-Tropsch reactor to synthesize hydrocarbon byproducts; and
c) blending at least a portion of said byproducts with said treated stream to
formulate a transportable synthetic crude oil with an API gravity of between
15 and 24 and a diesel fraction cetane number of not less than 40.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Referring now to the drawings as they generally describe the
invention,
reference will now be made to the accompanying drawings illustrating preferred
embodiments.
[0044] Figure 1 is a process flow diagram of methodology known in the prior
art for
processing of mineable and in situ heavy oil and bitumen;
100451 Figure 2 is a process flow diagram similar to Figure 1, illustrating
a further
technique known in the art;
CA 02809503 2014-05-22
[0046] Figure 3 is a process flow diagram illustrating a further variation
of the prior art
technology;
[00471 Figure 4 is a process flow diagram illustrating a further variation
of the prior art
technology;
[00481 Figure 5 is a process flow diagram illustrating an embodiment of the
present
invention;
[00491 Figure 6 is a process flow diagram illustrating a further embodiment
of the
present invention;
[00501 Figure 7 is a process flow diagram illustrating yet another
embodiment of the
present invention;
[0051] Figure 8 is a process flow diagram illustrating one embodiment for a
partial
upgrading process for formulating partially upgraded synthetic crude oil; and
[0052] Figure 9 is a graphical representation of blend composition for
typical crude
assays.
[0053] Similar numerals employed in the figures denote similar elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Referring now to Figure 1 , shown is a first embodiment of a bitumen
production
flow diagram based on the prior art. The overall process is denoted by 10. In
the process,
the heavy oil or bitumen source 12 may comprise a bitumen reservoir which may
be
minable or in situ. Generally speaking, the bitumen then may be transported to
a heavy oil
or bitumen production unit 14 into which diluent or solvent may be introduced
via line 16
from a heavy oil or bitumen upgrader 18. The diluent or solvent can comprise
any suitable
material well known to those skilled in the art such as suitable liquid
alkanes as an
example. Once the diluent is introduced via line 16 into the production unit
14, the result
is a mobilizable bitumen blend (dilbit). Once the dilbit or diluted bitumen
blend is
processed in the upgrader 18, the so formed synthetic crude, globally denoted
by 20 is then
16
CA 02809503 2014-05-22
treated in a petroleum refinery 22 where subsequently refined products are
formulated and
with the refined products being globally denoted by 24.
100551 The production unit 14 primarily removes water and solids from the
stream. The
diluent or solvent 16 is added to the raw bitumen to provide for the necessary
mobilization
and separation parameters, primarily providing a reduction in viscosity. In a
situation
where the bitumen is an oil sand derived bitumen, water is added to the raw
material to
provide a slurry for transport to the extraction and froth treatment plant and
upgrader 18, as
further described in Figure 2. Dewatered bitumen is then transported by
pipeline (not
shown) as a diluent blend or dilbit to the upgrader 18. The dry raw bitumen is
treated to
primary and secondary treatment to create a sweet or sour crude oil (SCO). The
SCO is
transported to the petroleum refinery 22 to be further processed into refined
product 24 as
indicated above, examples of which include transport fuel such as gasoline,
diesel and
aviation fuels, lube oils and other feedstocks for petrochemical conversion.
[0056] With respect to Figure 2, shown is a schematic process flow diagram
of oil sands
operation for bitumen upgrading. The overall process in this flow diagram is
indicated by
30. Other than the embodiment shown, the system relates to a minable oil sands
bitumen
production process where raw mined oil sands ore, generally denoted by 32,
from the mine
are mixed with water 34 in an ore preparation unit 36 and subsequently
hydrotransported
to a primary extraction plant, denoted by 38. In the extraction plant 38, the
greater portion
of water 34 and course tailings 40 are separated and returned to a tailings
pond 42.
[0057] Partially dewatered bitumen, generally denoted by 44 is transferred
to a froth
treatment unit 46. This is where a solvent, typically highly aromatic naphtha
(derived from
bitumen) or paraffinic solvent (derived from natural gas liquids) is added at
48 to separate
the remaining water and refined clays as well as fine tailings. The froth is
then treated in a
solvent recovery unit 52 where the majority of the solvent is recovered for
recycle to the
froth treatment unit. The separated fine tailings passes through a tailings
solvent recovery
unit 50 for final recovery of solvent. The fine tailings are transferred into
the tailings pond
42. The clean dry froth is then introduced into the bitumen upgrader,
generally denoted by
54 and illustrated in Figure 2 in dashed line. Generally speaking the bitumen
upgrader 54
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incorporates two general processes, a primary and secondary upgrading. The
primary
upgrader typically consists of two processing methodologies. The first,
namely, carbon
rejection or coking where the heavy fraction of the bitumen is removed as
petcoke.
Generally, the synthetic crude oil yield is between about 80 to about 85% by
volume and
the remaining portion converted primarily by petcoke is returned for storage
to the mine.
Further the coking process is a severe processing method and leads to higher
aromatic
content in the synthetic crude oil. The second process, namely hydrogen
addition, uses a
slurry based catalytic hydroprocessing system with the addition of hydrogen to
treat the
bitumen blend and produce an asphaltene reject and synthetic crude oil
product. The yield
of the synthetic crude oil typically exceeds 100% due to product swelling.
100581 The hydrocarbon product streams from primary upgrading are further
treated in
secondary upgrader, consisting of hydrotreating units using hydrogen to
stabilize synthetic
crude products generally indicated as 56 and reduce sulfur and nitrogen
impurities. Natural
gas is used in a hydrogen unit to generate hydrogen requirements for the
upgrader and co-
generate electric power for upgrader use. The overall operations in the
bitumen upgrader
are indicated within the dash lines and these operations are well known to
those skilled in
the art.
[0059] Turning
to Figure 3, shown is a further partial upgrading process known in the
prior art, in this arrangement, the process flow diagram delineates an in situ
bitumen
production unit. The overall process is denoted by 60. In such an arrangement,
the in situ
heavy oil or bitumen is exposed to steam to extract the oil. The raw bitumen
62 is treated
in a conventional SAGD or CSS plant 64 to remove water 66. Diluent 68 is
typically
added to raw bitumen 62 in plant 64 to create water oil separation and to
further provide a
diluted blend for pipeline transportation, more commonly referred to in the
art as "dilbit"
denoted by 70. The dilbit can be transported over long distances in a pipeline
(not shown)
to remote refineries where it is blended with conventional crude as a
feedstock. More
integrated configurations may use distillation, deasphalting or visbreaking, a
processing to
create a near bottomless sour heavy crude for feed to refineries. This
operation creates an
asphaltene or vacuum residue stream requiring disposal. This partially
upgraded bitumen
18
CA 02809503 2014-05-22
is suitable for pipeline transportation for heavy oil feed streams greater
than 15 API. For
heavy oil and bitumen feed streams less than 15 API, some quantity of diluent
is still
required to meet crude pipeline specifications. The dilbit is processed in a
bitumen partial
upgrader denoted by 72 with the operations being shown within the dashed line
box. The
transportable bitumen is denoted by 74 in Figure 3.
[0060] As will be appreciated by those skilled, the process variations
shown in Figures
I through 3 of existing bitumen and heavy oil production facilities either
create a waste
product such as petcoke or residuum which leads to significant losses or
further requires
significant quantities of hydrogen or diluent to upgrade the product in order
to be suitable
as a refinery feedstock. Essentially, the existing processes do not provide a
technology
capable of capturing the full intrinsic value of the bitumen or heavy oil and
has resulted in
environmental impact related to disposal and management of undesirable waste
products.
[0061] Turning to Figure 4, shown is a further variation in the prior art
of an enhanced
bitumen upgrading process. It is the subject matter of Canadian Patent No.
2,439,038 and
its United States homolog, U.S. Patent No. 7, 407,571 issued to Rettger, et.
al. (Ormat
Industries Ltd.).
[0062] The overall process is denoted by 80.
[0063] Dilbit or froth 70 is introduced into an atmosphere of distillation
unit 82 with the
non-distilled heavy bottoms being transported and introduced into a solvent
deasphalting
unit (SDA) 84 and the asphaltene bottoms are then subsequently fed into a
gasifier 86,
which gasifier is within the Ormat gasification unit, globally denoted by 88.
The
deasphalted material, commonly denoted as DA0 is transferred to the
hydroprocessing
unit 108 for upgrading to synthetic crude oil. As an option, there may be a
vacuum
distillation unit 110 in the circuit which may introduce captured vacuum
gasoils for
introduction into hydroprocessing unit 108. Similarly, the vacuum bottoms are
introduced
into the SDA 84 to optimize process configuration.
[0064] The sour syngas generated by the gasification unit is then passed
into a syngas
treater 90 for acid gas removal. The acid gas is removed at 92 and treated in
sulfur plant 94
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producing at least products such as liquid sulfur 96 and CO2 98. The treated
or "sweet"
syngas is then processed in a water gas shift reaction (WGS) process as
denoted in the
Figure 4 and referred to as a CO shift reactor 100. Steam 102 is augmented in
the reactor
100. The water gas shift reaction is merely a shift from the CO to CO2 to
create a
hydrogen rich syngas. The hydrogen rich syngas may be then further treated in
a typical
pressure swing unit (PSA) or a membrane unit where the hydrogen is
concentrated to
greater than 99 per cent. It occurs in unit 104. The hydrogen generated by
104, denoted
by 106 is then the feedstock for the hydroprocessing unit 108. Once the
hydroprocessing
occurs, the result is synthetic crude oil (SCO) denoted by 116 and fuel gas
denoted by 114.
[0065] Returning briefly to the hydrogen recovery unit 104, the byproduct of
the unit
104 is a tailgas or a low BTU syngas which is used in the SAGD thermal steam
generators
as fuel to offset the need for natural gas as the primary fuel. The process
has merit in that
if natural gas is in short supply or there can be significant historic price
fluctuation, the
enhanced upgrader process is less dependent on the natural gas and can rely on
the
synthesized fuel for the overall process benefits.
[0066] Turning to Figure 5, shown as a first embodiment of an enhanced bitumen
upgrading circuit process incorporating Fischer-Tropsch technology and
hydrogen
synthesis. The embodiment of the overall process is denoted by 120. The
overall process
is particularly beneficial relative to the processes that were previously
proposed in the prior
art in that sweet carbon rich syngas is not passed through a water gas shift
reaction, as
denoted as 100 in Figure 4, but rather is supplemented with external hydrogen
138 to
create the optimum syngas composition, typically a ratio of hydrogen to carbon
monoxide
of greater than 1.8:1 to 2.2:1, and preferred as 2:1 as feed to Fischer-
Tropsch reactor for
producing high quality paraffinic Fischer-Tropsch liquids.
[0067] It is by
the recognition of the usefulness of the Fischer-Tropsch reactor together
with the avoidance of waste petcoke/residuum generation and the subsequent
hydrogen
source addition to maximize conversion of gasified carbon, that draws the
proposed
interim technology into the realm of being economical, convenient and highly
efficient
given the yields that are generated for the synthetic crude oil (SCO).
CA 02809503 2014-05-22
[0068] As is evident, there are a number of unit operations which are
common with
those in the prior art, namely the atmospheric distillation, vacuum
distillation, solvent
deasphalting, hydroprocessing, gasification, and syngas treatment.
[0069] In the embodiment shown, the Ormat gasification, commonly denoted as
unit 88
and discussed with respect to Figure 4 is replaced with a further sequence of
operations
(the XTL operations) shown in dashed lines and indicated by 122. In this
embodiment, the
gasifier 86 converts the non-distilled bottoms residue with typically oxygen
(02) 124 to
generate a hydrogen lean or carbon rich syngas 88 having a hydrogen to carbon
dioxide
ratio in range of 0.5:1 to 1.5:1, more specifically about 1:1, an example of
which is shown
in Table 1.
Table 1 - Typical XTL Gasifier Hydrogen Lean Syngas Compositions
Feedstock Type Heavy Fuel Oil Vacuum Residue
Asphaltene
Syngas Composition (mole%)
Carbon Dioxide (CO2) 2.75% 2.30% 5.0%
Carbon Monoxide (CO) 49.52% 52.27% 50.4%
Hydrogen (H2) 46.40% 43.80% 42.9%
Methane (CH4) 0.30% 0.30% 0.3%
Nitrogen (+Argon)(N2) 0.23% 0.25% 0.4%
Hydrogen Sulfide (H2S) 0.78% 1.08% 1.0%
____________________________________________________________________ --
[0070] A common byproduct, containing heavy metals and ash, from the
gasification is
discharged as slag denoted as 126. The hydrogen lean syngas 88 is then passed
into the
syngas treatment unit 90 for removal of acid gases 92 to create a sweet
hydrogen lean
syngas 91. Additional scrubbing, adsorption and washing technologies (not
shown), well
known to those skilled in the art, are typically employed to ensure that the
sweet syngas is
devoid of contaminants such as sulfur compounds which will have significant
detrimental
impact on the Fischer-Tropsch catalyst. The acid gas is further treated in the
sulfur plant 94
21
CA 02809503 2014-05-22
to generate elemental sulfur 96 and carbon dioxide (CO2) as was the case with
respect to
the process of Figure 4. The sweet hydrogen lean syngas 91 is then passed into
a Fischer-
Tropsch unit reactor denoted by 128. As a possibility, the hydrocarbon by
products that
are formed subsequently to reaction within the Fischer-Tropsch reactor 128
includes
Fischer-Tropsch vapours 184 (CO-FH2+Cl+C2+C3+C4), naphtha 130, light Fischer-
Tropsch liquids 132 (LFTL) and heavy Fischer-Tropsch liquids (HFTL) 134 or
commonly
know as FT wax.
100711 In order
to trim or improve the efficiency of the overall process, the XTL unit
122 and specifically in advance of the syngas treatment unit 90 and/or the
Fischer-Tropsch
reactor 128 may be augmented with an external supply of hydrogen, indicated by
136 and
138, respectively. Further, at least some of the vapour from the Fischer-
Tropsch reactor
may be reintroduced in advance of the syngas treatment unit 90 as indicated by
140, and/or
be used a fuel 114 in the upgrader. The liquids 130, 132 and 134 are
introduced into
hydroprocessing unit 108. This may also be augmented by straight run
distillate naphtha
144 may be introduced from atmospheric distillation operation 82, light vacuum
gas oil
(LVGO) 142 from the vacuum distillation operation 110 and optionally,
deasphalted oil
112 (DAO) from the SDA unit 84. A range of hydroprocessing treatments 108, as
an
example, hydrocracking, thermal cracking, isomerization, hydrotreating and
fractionation,
may be applied to the combined streams, individually or in desired
combinations, well
known to those skilled in the art, to create at least the synthetic crude oil
product 116. As
further options, any portion of the Fischer-Tropsch naphtha 130 particularly
the paraffinic
naphtha indicated by 150 may be reintroduced into the deasphalting unit 84 at
152 or
further distributed as the solvent make up 156 for introduction into the oil
sands froth
treatment unit (not shown but generally noted by 158).
[0072] Further,
additional hydrogen may be introduced into the hydroprocessing unit
108 and hydrotreating unit 160 at 166 and 164. The hydrogen supply may be
taken from
the hydrogen supply noted herein previously. From each of the fractionator,
hydrotreater
160, hydroprocessing unit 108 and Fischer-Tropsch unit 128, product from each
of these
operations denoted by 170, 172, 174 respectively is introduced to fuel gas
114. Further, a
22
CA 02809503 2014-05-22
portion of 172 and 170 rich in hydrogen may be combined with the hydrogen lean
syngas
at 88 or 91 to enrich this stream for optimum performance of the Fischer-
Tropsch unit.
[0073] Turning to Figure 6, shown in the process flow diagram is yet
another variation
on the methodology of the instant invention. The overall process in this
embodiment is
denoted by 180. Similar unit operations from those established in Figures 4
and 5 are
applicable in Figure 6.
100741 The primary changes with respect to Figure 5 versus Figure 6,
includes
modification of the XTL, unit 122 and incorporation of hydrogen rich syngas
generation
and recycle of hydrogen rich syngas generated in the Fischer-Tropsch unit 128.
100751 In greater detail, the XTL, unit 122 is modified to incorporate a
hydrogen rich
syngas generator, denoted by 182. The hydrogen rich syngas generator 182 is
typically
composed of a steam methane reformer (SMR) (not shown) or an auto thermal
reformer
(ATR) (not shown) and combinations thereof. Natural gas 188, Fischer-Tropsch
vapours
184, hydrogen rich fuel gas 174, etc. from the hydroprocessor 108 and
fractionation unit
160 and Fischer-Tropsch naphtha 186 may be supplied individually or in
combination to
unit 122 to generate hydrogen rich syngas 190 where the ratio between the
hydrogen and
the carbon monoxide is in range of 2:5 to 6:1. This is an important aspect of
the invention
and works in concert with the Fischer-Tropsch 128 to provide the effective
results realized
by practicing the technology as discussed herein with respect to Figures 5
through 6.
Natural gas 188, depending on the current market situation at any location or
time, may be
used as a primary feedstock to the hydrogen rich syngas generator 182 and the
steams 174,
130 and 184 may be used to maximize upgrader operation. Alternately, if the
natural gas
market is less favourable, streams 174, 130 and 184 may be fully utilized to
offset the need
for natural gas. The hydrogen rich syngas 190 can be introduced in advance of
the syngas
treatment unit 90 at 190 if treatment is required, or alternately, any portion
of the hydrogen
rich syngas 190 may be routed directly to the Ficher-Tropsch unit 128.
100761 In this manner, the hydrogen rich syngas 190 is combined with the
carbon rich
syngas to create an optimum Fischer-Tropsch syngas where the ratio of the
hydrogen to
carbon monoxide is preferred 2:1. The combined feed streams to unit 122
reduces the
23
CA 02809503 2014-05-22
amount of natural gas needed to achieve the optimum Fischer-Tropsch feed
stream,
thereby offering a commercial advantage of the upgraders dependence on natural
gas, but
also takes advantage of current low cost supply of natural gas.
[0077] Additionally, a portion of the hydrogen rich syngas 190 can be
introduced to
hydrogen unit 192 where a purified hydrogen stream 164 is generated for use in
the
hydroprocessing units 108 and 170. The hydrogen unit 192 may consist of a
pressure
swing adsorption (PSA), membrane or absorption technology, well known to those
skilled
in the art.
[0078] Turning to Figure 7, the process flow diagram illustrates a further
variation on
the overall concept of the present invention and in this manner, the XTL unit
122
undergoes further variation where the hydrogen unit 192 and hydrogen rich
syngas
generator 182 inherent in the embodiment Figure 6 are replaced with a water
gas shift
(WGS) reaction unit operation. The overall process of Figure 7 is denoted by
200. The
water gas shift unit is denoted by 202 and is disposed between the syngas
treatment unit 90
and the Fischer-Tropsch unit 128. As is known in the art and particularly by
those skilled,
the water gas shift reactor is useful to enrich the raw syngas which, in turn,
results in
optimization of the hydrogen to carbon monoxide ratio for the Fischer-Tropsch
syngas.
Steam supply for the WGS reaction unit 202 may be provided from the gasifier
86 shown
as 204. Additionally, hydrogen rich gas 171 and 173 from the hydroprocessor
units may
be combined with the FT vapours 140 to enrich the FT syngas feed.
[0079] Referring now to Figure 8, the process flow diagram is
representative of one
possible partial upgrading route. In the Figure, a partial upgrading process
is set forth for a
100,000 barrel bitumen feed circuit. It will be readily appreciated by those
skilled that here
are a number of unit operations which are common with the full upgrading
sequence of
operations delineated in respect of the previous drawings. The overall process
is denoted
by numeral 220. In this circuit, hydroprocessing typically attributable to
full upgrade
processing is eliminated and only the core steps observed to result in a
transportable
synthetic oil absent the significant diluent requirements.
24
CA 02809503 2014-05-22
[00801 As shown, the feedstock in the example is 100,000 barrels per day
(BPD) of 8.5
API 4.5% by weight sulfur bitumen. This may be introduced into the atmospheric
distillation unit (ADU); diluent recovery unit (DRU) 82 with dilbit 70 . The
atmospheric
bottoms with a volume in the example of 85,092 BPD at 6AP1 and 4.6% by weight
sulfur,
340 parts per million (ppm) nickel and vanadium is introduced into the solvent
deaspalting
unit (SDA) 84 and the deasphalted oil (DAO) 112 generated in an amount of
75,520 BPD
at 12 API and 4.0% weight sulfur with 100 ppm nickel and vanadium. Based on
one design
condition, the treatment in the SDA unit 84 results in an 85% volume lift for
the DAO.
[0081] Asphaltenes from the SDA unit 84 may be used in the XTL operations
supra in
the discussion of Figure 5 along with process oxygen 124, natural gas 222. The
asphaltenes, in this example, are at 12,572 BPD, -15 API, 5 % weight sulfur
and 895 ppm
nickel and vanadium. The Fischer-Tropsch naphtha 224 from the XTL operations
is
produced in a volume of 2,346 BPD at 72 API and the Fischer-Tropsch diesel 226
at
18,842 BPD at 53 API.
[0082] The straight run naphtha, light gas oil and light petroleum gases
(LPG) 144
product from the ADU/DRU unit 82 is produced in a volume of 16,878 BPD at 44
API.
[0083] As one example, the straight run naphtha, light gas oil and light
petroleum gases
144, DAO, Fischer-Tropsch naphtha 224 and Fischer-Tropsch diesel 226 are
blended to
result in a sour bottomless partially upgraded pipeline quality synthetic
crude oil (SCO)
230 in a volume of 109,326 BPD, 21 API with a viscosity of not greater than
350
centistokes (0.00035m2s-I) at 10 C. The volume yield in this example is 109 %,
weight
yield 100 % having a sulfur content of 3.3 % and nickel and vanadium content
of less than
70 ppm and CCR less than 6 wt%. Most appealing is the fact that the specific
gravity is
less than 1 and in this example .93, thus obviating the environmental hazards
with
convention techniques where the result exceeds the specific gravity of water.
[00841 In this example, the SCO 230 contains on a volume basis 9.8 % naphtha,
24.9%
distillate, 31.5 % vacuum gas oil and 33.8% vacuum resides.
CA 02809503 2014-05-22
100851 As a further example, the 100,000 BPD bitumen feed can be maximally
optimized by making suitable adjustments. The SDA unit 84 The atmospheric
bottoms
with a volume in the example of 85,092 BPD at 6API and 4.6% by weight sulfur,
340 parts
per million (ppm) nickel and vanadium is introduced into the solvent
deaspalting unit
(SDA) 84 and the deasphalted oil (DAO) 112 generated in an amount of 64,860
BPD at 14
API and 3.6% weight sulfur with 50 ppm nickel and vanadium. The treatment in
the SDA
unit 84 results in a 76% volume lift for the DAO.
[0086] Asphaltenes from the SDA unit 84 may be used in the XTL operations
supra in
the discussion of Figure 5 along with process oxygen 124, natural gas 222. The
asphaltenes, in this example, are at 20,232 BPD, -10 API, 6 % weight sulfur
and 830 ppm
nickel and vanadium. The Fischer-Tropsch naphtha 224 from the XTL operations
is
produced in a volume of 3,715 BPD at 72 API and the Fischer-Tropsch diesel 226
at
30,322 BPD at 53 API.
[00871 The straight run naphtha, light gas oil and light petroleum gases
(LPG) 144
product from the ADU/DRU unit 82 is produced in a volume of 16,878 BPD at 44
API.
[00881 The straight run naphtha, light gas oil and light petroleum gases
144, DAO,
Fischer-Tropsch naphtha 224 and Fischer-Tropsch diesel 226 are blended to
result in a
sour bottomless partially upgraded pipeline quality synthetic crude oil (SCO)
230 in a
volume of 114,575 BPD, 24 API with a viscosity of not greater than 300
centistokes at 10
C. The volume yield in this example is 115 %, weight yield 100 % having a
sulfur content
of 2.5 % and nickel and vanadium content of not greater than 30 ppm and a CCR
level less
than 4 wt%. In this example, the specific gravity is .91;the SCO 230 contains
on a volume
basis 10.6 % naphtha, 33.8% distillate, 31.5 % vacuum gas oil and 24.1 %
vacuum resides.
100891 It will be appreciated by those skilled in the art that the
processes described
herein provide a variety of possibilities for partial upgrading or full
upgrading, owing to
the fact that the unit operations can be reconfigured to achieve the desired
result. As an
example, the bottoms fraction that is sent to the syngas generating circuit
described herein
previously can be used for formulating a hydrogen lean gas stream via a
partial oxidation
reaction. The reaction may be catalytic or non-catalytic. This reaction
product can be then
26
CA 02809503 2014-05-22
treated in a Fischer-Tropsch reactor to synthesize hydrocarbon byproducts
while at least a
portion of partially upgraded synthetic crude oil can be removed for pipeline
distribution.
[00901 The partially upgraded synthetic crude oil may optionally include
externally
supplied diluent. What is meant by the external supply is a diluent that is
supplied from a
source that is extraneous from the circuit.
100911 In terms of the API gravity, this can very significantly be
dependent upon the
intended use or transportation mode of the synthetic crude oil. As an example,
the API
gravity for the partial upgrading may vary from 15 to 24 API. Conveniently,
the partially
upgraded synthetic oil is completely converted to at least one of fully
upgraded synthetic
crude oil, gasoline, jet fuel and diesel fuel and the upgrading is achieved
absent of coke,
unconverted residuum and waste byproducts. It has been found that by following
the
protocol as established herein, the upgraded synthetic crude oil may be
formulated
substantially devoid of bottoms material having a final distillation boiling
point of 950 F or
greater.
[0092] Advantageously, the specific gravity of the synthetic crude oil is
less than 1
which is particularly beneficial from an environmental point of view in the
event of a spill
or a discharge of synthetic crude oil into a water body. The synthetic crude
oil Ruined in
accordance with the partial upgrading procedure has a total acid number of
less than 3,
more preferred less than 1.
[00931 Figure 9 illustrates assay composition for typical crude oils in
comparison with
the partially upgraded SCO delineated above relative to the SCO synthesized in
accordance
with the partial upgrading techniques set forth herein.
[0094] The blending may include at least a portion of the distilled or
separated fraction
with the partially upgraded crude oil as has been elucidated herein
previously. The distilled
or separated fractions may comprise any portion of straight run distillate
(AGO), naphtha,
vacuum gas oil, (VGO) or deasphalted oil, (DAO). As discussed previously, the
fractions
may be optionally further hydroprocessed separately or in combination. The
hydroprocessing operations are known to those skilled and can include by way
of example
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CA 02809503 2014-05-22
and without being limiting hydrocracking, visbreaking, thermocracking,
hydrotreating,
isomerization, fractionation or any combination of these or other suitable
options to
achieve the hydroprocessing result within the purview of those skilled in the
art.
100951 One of the clear benefits by the variable operations that have been
discussed in
the specification for synthesizing hydrocarbons, hydrocarbon byproducts, etc.
is that in the
instance where the partially upgraded synthetic crude oil, transportation is
easily
achievable using pipeline, rail, marine, vehicular transport as well as any
and all
combinations of these.
[0096] The partially upgraded synthetic crude oil that can be synthesized
using the
protocol discussed herein results in a product where the diesel fraction with
a cetane
number is greater than 40, more preferred greater than 55 cetane. Conversion
of the
bitumen feedstock to the partially upgraded crude oil is at least 100 volume %
with a
typical yield greater than 100 volume %.
28
