Note: Descriptions are shown in the official language in which they were submitted.
PRODUCTION OF CARBON FIBER FROM ASPHALTENES
IN THE PRESENCE OF A POLYMER
TECHNICAL FIELD
[001] The technical field generally relates to a process and system for
producing carbon
fibers from asphaltenes present in a heavy hydrocarbon feedstock. More
particularly, the
technical field relates to a process and system involving several treatments
to pre-condition
the carbon fiber feedstock before obtaining the final carbon fiber product.
BACKGROUND
[002] Carbon fibers have been used for decades in several industries including
aerospace,
civil engineering, military, motorsports, along with other competition sports,
to name a few
examples. Carbon fibers present properties such high stiffness, high tensile
strength, low
weight to strength ratio, high chemical resistance, high temperature tolerance
and low thermal
expansion, which made them very popular in industry. It is desirable to be
able to produce
carbon fiber for industry from readily available materials.
[003] Some aspects of the present technology will become readily apparent
to those skilled
in the art from the following detailed description, wherein various
implementations are shown
and described by way of illustration. The drawings and detailed description
are to be regarded
as illustrative in nature and not as restrictive.
SUMMARY
[004] In some implementations, the present technology relates to a process for
producing a
carbon fiber product from a heavy hydrocarbon feedstock comprising native
asphaltenes,
comprising:
solvent deasphalting the heavy hydrocarbon feedstock comprising native
asphaltenes
with a solvent to precipitate asphaltenes and form solid asphaltene
precipitates and
produce deasphalted oil;
separating the deasphalted oil from the solid asphaltene precipitates to
recover a
slurry stream comprising the asphaltene precipitates and residual solvent;
1
Date Recue/Date Received 2022-09-13
separating the slurry stream to produce a solid asphaltene particulate
material and a
recovered solvent stream;
treating the solid asphaltene particulate material to obtain the carbon fiber
product.
[005] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
[006] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C3-C8 hydrocarbon.
[007] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one of C5-C8 hydrocarbon.
[008] In some implementations, the solvent used for the solvent deasphalting
comprises a
mixture of C5-C8 hydrocarbons.
[009] In some implementations, the solid asphaltene particulate material
comprises 95 wt %
or more C5+ asphaltenes.
[0010] In some implementations, separating the slurry stream comprises
vaporizing the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and subjecting the vapour/solid mixture to inertial
separation.
[0011] In some implementations, treating the solid asphaltene particulate
material comprises:
extruding the solid asphaltene particulate material to produce extruded
asphaltenes;
spinning the extruded asphaltenes into a continuous asphaltene thread;
heat treating the continuous asphaltene thread to produce a stabilized
asphaltene
thread;
carbonizing the stabilized asphaltene thread to produce a carbonized carbon
fiber;
and
conditioning the carbonized carbon fiber to produce the carbon fiber product.
2
Date Recue/Date Received 2022-09-13
[0012] In some implementations, spinning comprises melt spinning.
[0013] In some implementations, heat treating is performed at about 175 C to
about 290 C
(about 350 F to about 550 F) for up to 1 hour.
[0014] In some implementations, carbonizing is performed at about 995 C to
about 2000 C
(about 1823 F to about 3632 F) for up to 1 hour.
[0015] In some implementations, conditioning comprises surface treating and
sizing the
carbonized carbon fiber to create the carbon fiber product.
[0016] In some implementations, the carbon fiber product has a tensile
strength of at least 100
M Pa and a Young's modulus of at least 20 GPa.
[0017] In some implementations, the process further comprising separating
insolubles from
the solid asphaltene particulate product, wherein separating the insolubles
comprises
combining the solid asphaltene particulate product with an insolubles-
producing solvent to
produce the insolubles, and removing the insolubles from the solid asphaltene
particulate
product.
[0018] In some implementations, the insolubles-producing solvent is a
saturated or
unsaturated cyclic or heterocyclic hydrocarbon.
[0019] In some implementations, the insolubles-producing solvent is one or
more of toluene,
xylene, benzene, tetrahydrofuran, cyclohexanone, quinoline or pyridine.
[0020] In some implementations, conditioning comprises graphitization of the
carbonized
carbon fiber to form a graphitized carbon fiber, and surface treating and
sizing the graphitized
carbon fiber to create the carbon fiber product.
[0021] In some implementations, graphitization comprises heating the carbon
fiber to over
3000 C (5432 F).
[0022] In some implementations, conditioning comprises graphitization of the
carbonized
carbon fiber to form a graphitized carbon fiber, activating the graphitized
carbon fiber to form
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Date Recue/Date Received 2022-09-13
an activated carbon fiber, and then surface treating and sizing the activated
carbon fiber to
create the carbon fiber product.
[0023] In some implementations, the graphitized carbon fiber is activated by
steam activation.
[0024] In some implementations, activation is performed at a steam temperature
of about 800
C to 900 C and a steam rate of about 100 g/hr to about 200 g/hr.
[0025] In some implementations, the activated carbon fiber has a BET surface
area of at least
500 m2/g.
[0026] In some implementations, the activated carbon fiber has a BET surface
area of at least
1000 m2/g.
[0027] In some implementations, the carbon fiber product has a tensile
strength of at least 1.5
GPa and a Young's modulus of at least 200 GPa.
[0028] In some implementations, the present technology relates to a system for
producing a
carbon fiber product from a heavy hydrocarbon feedstock comprising native
asphaltenes,
comprising:
a solvent deasphalting separator configured to contact the heavy hydrocarbon
feedstock stream comprising native asphaltenes with a solvent to precipitate
asphaltenes and form solid asphaltene precipitates, the solvent deasphalting
separator producing a solvent-diluted deasphalted oil stream comprising at
least a
portion of the solvent and a slurry stream comprising the asphaltene
precipitates and
residual solvent;
an inertial separation unit in fluid communication with the solvent
deasphalting
separator, the inertial separation unit being configured to separate the
slurry stream
solids to produce a solid asphaltene particulate product and a recovered
solvent
stream;
conversion units to treat the solid asphaltene particulate material and
produce the
carbon fiber product.
4
Date Recue/Date Received 2022-09-13
[0029] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
[0030] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C3-C8 hydrocarbon.
[0031] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C5-C8 hydrocarbon.
[0032] In some implementations, the solvent used in the solvent deasphalting
separator
comprises a mixture of C5-C8 hydrocarbons.
[0033] In some implementations, the solid asphaltene particulate material
comprises 95 wt %
or more C5+ asphaltenes.
[0034] In some implementations, the inertial separation unit is configured to
vaporize the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and to separate the vapour/solid mixture to recover
the solid
asphaltene particulate stream.
[0035] In some implementations, the conversion units comprise:
an extruding unit configured to extrude the solid asphaltene particulate
material
separated in the inertial separation unit, to produce extruded asphaltenes;
a spinning unit configured to melt spin the extruded asphaltenes into a
continuous
asphaltene thread;
a first heater configured to stabilize the asphaltene thread to produce a
stabilized
asphaltene thread;
a second heater configured to carbonize the stabilized asphaltene thread to
produce
a carbonized carbon fiber;
a surface and sizing treatment unit configured to surface treat and size the
carbonized
carbon fiber or a carbon fiber derived from the carbonized carbon fiber to
produce the
carbon fiber product.
Date Recue/Date Received 2022-09-13
[0036] In some implementations, the spinning unit comprises a melt spinning
unit.
[0037] In some implementations, the first heater is operated at about 175 C to
about 290 C
(about 350 F to about 550 F) for up to 1 hour to stabilize the asphaltene
thread.
[0038] In some implementations, the second heater is operated at about 995 C
to about
2000 C (about 1823 F to about 3632 F) for up to 1 hour to carbonize the
stabilized asphaltene
thread.
[0039] In some implementations, the system further comprises an insolubles
separation unit
configured to contact the solid asphaltene particulate product with an
insolubles-producing
solvent and to separate the insolubles from the solid asphaltene particulate
product.
[0040] In some implementations, the insolubles-producing solvent is a
saturated or
unsaturated cyclic or heterocyclic hydrocarbon.
[0041] In some implementations, the insolubles-producing solvent is one or
more of toluene,
xylene, benzene, tetrahydrofuran, cyclohexanone, quinoline or pyridine.
[0042] In some implementations, the system further comprises a graphitization
unit after the
second heater configured to heat the carbonized carbon fiber and produce the
derived carbon
fiber in the form of a graphitized carbon fiber.
[0043] In some implementations, the system further comprises:
a graphitization unit after the second heater configured to heat the
carbonized carbon
fiber and produce a graphitized carbon fiber, and
an activation unit configured to activate the graphitized carbon fiber and
produce the
derived carbon fiber in the form an activated carbon fiber.
[0044] In some implementations, the activation unit comprises a steam
activation unit.
[0045] In some implementations, the steam activation unit is operated at a
steam temperature
of about 800 C to about 900 C and a steam rate of about 100 g/hr to about
200 g/hr.
6
Date Recue/Date Received 2022-09-13
[0046] In some implementations, the graphitization unit is operated at a
temperature over
3000 C (5432 F).
[0047] In some implementations, the present technology further relates to a
process for
producing a carbon fiber product comprising:
extruding a solid asphaltene particulate product in the presence of a polymer
to
produce an extruded polymer-asphaltenes product;
treating the extruded polymer-asphaltenes product to generate the carbon fiber
product.
[0048] In some implementations, the solid asphaltene particulate material
comprises 95 wt %
or more C5+ asphaltenes.
[0049] In some implementations, the polymer comprises a thermoplastic polymer.
[0050] In some implementations, the polymer comprises an acrylic, polyolefin,
polyester,
polystyrene, polyvinylchloride, or any mixture thereof.
[0051] In some implementations, the polymer comprises a polypropylene,
polyethylene,
polyvinylchloride, or any mixture thereof.
[0052] In some implementations, the solid asphaltene particulate material is
obtained by:
solvent deasphalting a heavy hydrocarbon feedstock with a solvent to
precipitate
asphaltenes and form solid asphaltene precipitates and produce deasphalted
oil;
separating the deasphalted oil from the solid asphaltene precipitates to
produce a
solvent-diluted deasphalted oil stream comprising at least a portion of the
solvent and
a slurry stream comprising the asphaltene precipitates and residual solvent;
separating the slurry stream to produce the solid asphaltene particulate
material and
a recovered solvent stream.
7
Date Recue/Date Received 2022-09-13
[0053] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock recovered from a surface mining operation or an in situ
extraction
operation.
[0054] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C3-C8 hydrocarbon.
[0055] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C5-C8 hydrocarbon.
[0056] In some implementations, the solvent used for the solvent deasphalting
comprises a
mixture of C5-C8 hydrocarbons.
[0057] In some implementations, separating the slurry stream comprises
vaporizing the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and subjecting the vapour/solid mixture to inertial
separation.
[0058] In some implementations, treating the extruded polymer-asphaltenes
product
comprises:
spinning the extruded polymer-asphaltenes product into a continuous polymer-
asphaltene thread;
heat treating the continuous polymer-asphaltene thread to produce a stabilized
polymer-asphaltene thread;
carbonizing the stabilized polymer-asphaltene thread to produce a carbonized
carbon
fiber; and
conditioning the carbonized carbon fiber to produce the carbon fiber product.
[0059] In some implementations, spinning comprises wet spinning.
[0060] In some implementations, heat treating is performed at about 175 C to
about 290 C
(about 350 F to about 550 F) for up to 1 hour.
8
Date Recue/Date Received 2022-09-13
[0061] In some implementations, carbonizing is performed at about 995 C to
about 2000 C
(about 1823 F to about 3632 F) for up to 1 hour.
[0062] In some implementations, conditioning comprises surface treating and
sizing the
carbonized carbon fiber to create the carbon fiber product.
[0063] In some implementations, the carbon fiber product has a tensile
strength of at least 3.5
GPa and a Young's modulus of at least 250 GPa.
[0064] In some implementations, conditioning comprises graphitization of the
carbonized
carbon fiber to form a graphitized carbon fiber, and surface treating and
sizing the graphitized
carbon fiber to create the carbon fiber product.
[0065] In some implementations, graphitization comprises heating the carbon
fiber to over
3000 C (5432 F).
[0066] In some implementations, conditioning comprises graphitization of the
carbonized
carbon fiber to form a graphitized carbon fiber, activating the graphitized
carbon fiber to form
an activated carbon fiber, and then surface treating and sizing the activated
carbon fiber to
create the carbon fiber product.
[0067] In some implementations, the graphitized carbon fiber is activated by
steam activation.
[0068] In some implementations, activation is performed at a steam temperature
of about 800
C to about 900 C and a steam rate of about 100 g/hr to about 200 g/hr.
[0069] In some implementations, the activated carbon fiber has a BET surface
area of at least
500 m2/g.
[0070] In some implementations, the activated carbon fiber has a BET surface
area of at least
1000 m2/g.
[0071] In some implementations, the carbon fiber product has a tensile
strength of at least 3.5
GPa and a Young's modulus of at least 250 GPa.
[0072] In some implementations, the present technology also relates to system
for producing
a carbon fiber product comprising:
9
Date Recue/Date Received 2022-09-13
an extruding unit configured to extrude a solid asphaltene particulate product
in the
presence of a polymer to produce an extruded polymer-asphaltenes product;
conversion units to treat the extruded polymer-asphaltenes product and produce
the
carbon fiber product.
[0073] In some implementations, the extruding unit is provided with a mixer to
blend the
polymer and the solid asphaltene particulate product and an extruder to
extrude the blend and
produce the extruded polymer-asphaltenes product.
[0074] In some implementations, the system further comprises a mixing unit to
blend the
polymer and the solid asphaltene particulate upstream of the extruding unit.
[0075] In some implementations, the solid asphaltene particulate material
comprises 95 wt %
or more C5+ asphaltenes.
[0076] In some implementations, the polymer comprises a thermoplastic polymer.
[0077] In some implementations, the polymer comprises an acrylic, polyolefin,
polyester,
polystyrene, polyvinylchloride, or any mixture thereof.
[0078] In some implementations, the polymer comprises a polypropylene,
polyethylene,
polyvinylchloride, or any mixture thereof.
[0079] In some implementations, the system further comprises:
a solvent deasphalting separator configured to contact a heavy hydrocarbon
feedstock stream with a solvent to precipitate asphaltenes and form solid
asphaltene
precipitates, the solvent deasphalting separator producing a solvent-diluted
deasphalted oil stream comprising at least a portion of the solvent and a
slurry stream
comprising the asphaltene precipitates and residual solvent;
an inertial separation unit in fluid communication with the solvent
deasphalting
separator, the inertial separation unit being configured to separate the
slurry stream
solids to produce the solid asphaltene particulate material and a recovered
solvent
stream.
Date Recue/Date Received 2022-09-13
[0080] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
[0081] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C3-C8 hydrocarbon.
[0082] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C5-C8 hydrocarbon.
[0083] In some implementations, the solvent used in the solvent deasphalting
separator
comprises a mixture of C5-C8 hydrocarbons.
[0084] In some implementations, the inertial separation unit is configured to
vaporize the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and to separate the vapour/solid mixture to recover
the solid
asphaltene particulate material.
[0085] In some implementations, the conversion units comprise:
a spinning unit configured to melt spin the extruded polymer-asphaltenes
product into
a continuous polymer-asphaltene thread;
a first heater configured to stabilize the polymer-asphaltene thread to
produce a
stabilized polymer-asphaltene thread;
a second heater configured to carbonize the stabilized polymer-asphaltene
thread to
produce a carbonized carbon fiber;
a surface and sizing treatment unit configured to surface treat and size the
carbonized
carbon fiber or a carbon fiber derived from the carbonized carbon fiber to
produce the
carbon fiber product.
[0086] In some implementations, the spinning unit comprises a wet spinning
unit.
[0087] In some implementations, the first heater is operated at about 175 C to
about 290 C
(about 350 F to about 550 F) for up to 1 hour to stabilize the asphaltene
thread.
11
Date Recue/Date Received 2022-09-13
[0088] In some implementations, the second heater is operated at about 995 C
to about
2000 C (about 1823 F to about 3632 F) for up to 1 hour to carbonize the
stabilized asphaltene
thread.
[0089] In some implementations, the system further comprises a graphitization
unit after the
second heater configured to heat the carbonized carbon fiber and produce the
derived carbon
fiber in the form of a graphitized carbon fiber.
[0090] In some implementations, the system further comprises:
a graphitization unit after the second heater configured to heat the
carbonized carbon
fiber and produce a graphitized carbon fiber, and
an activation unit configured to activate the graphitized carbon fiber and
produce the
derived carbon fiber in the form of an activated carbon fiber.
[0091] In some implementations, the activation unit comprises a steam
activation unit.
[0092] In some implementations, the steam activation unit is operated at a
steam temperature
of about 800 C to about 900 C and a steam rate of about 100 g/hr to about 200
g/hr.
[0093] In some implementations, the graphitization unit is operated at a
temperature over
3000 C (5432 F).
[0094] In some implementations, the present technology further relates to a
process for
producing a carbon fiber product comprising:
adding at least one chemical agent to a solid asphaltene particulate material
to
produce a chemically treated asphaltene particulate product where the chemical
agent comprises a Lewis acid, a reducing agent, an oxidizing agent or any
mixture
thereof;
converting the chemically treated asphaltene particulate product into the
carbon fiber
product.
[0095] In some implementations, addition of the chemical agent is performed
under heating.
12
Date Recue/Date Received 2022-09-13
[0096] In some implementations, heating is performed at a temperature of about
140 C to
about 335 C.
[0097] In some implementations, addition of the chemical agent is combined
with sparging.
[0098] In some implementations, addition of the chemical agent is combined
with nitrogen
sparging.
[0099] In some implementations, the chemical agent comprises one or more
oxidizing agents.
[00100] In some implementations, the oxidizing agent is at least one compound
comprising
bromine, silver, chromium, manganese, and/or oxygen, or is a peroxide.
[00101] In some implementations, the chemical agent comprises KMn04, H202 or a
combination thereof.
[00102] In some implementations, the chemical agent comprises a Lewis acid
which is
aluminum chloride, boron chloride, iron chloride, tin chloride, titanium
chloride, aluminum
bromide, boron bromide, iron bromide, tin bromide, titanium bromide, or any
mixture thereof.
[00103] In some implementations, the chemical agent comprises one or more
reducing
agents.
[00104] In some implementations, the reducing agent is at least one compound
comprising
lithium, sodium, potassium, magnesium, aluminum, or zinc.
[00105] In some implementations, the chemical agent comprises one or more
reducing agents
selected from sodium hydroxide, potassium hydroxide, a molten sodium salt, a
molten
potassium salt, urea, NaBH4, and any mixture thereof.
[00106] In some implementations, the solid asphaltene particulate material
comprises 95 wt
% or more C5+ asphaltenes.
[00107] In some implementations, the solid asphaltene particulate material is
obtained by:
solvent deasphalting a heavy hydrocarbon feedstock with a solvent to
precipitate
asphaltenes and form solid asphaltene precipitates and produce deasphalted
oil;
13
Date Recue/Date Received 2022-09-13
separating the deasphalted oil from the solid asphaltene precipitates to
produce a
solvent-diluted deasphalted oil stream comprising at least a portion of the
solvent and
a slurry stream comprising the asphaltene precipitates and residual solvent;
separating the slurry stream to produce the solid asphaltene particulate
material and
a recovered solvent stream.
[00108] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock recovered from a surface mining operation or an in situ
extraction
operation.
[00109] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C3-C8 hydrocarbon.
[00110] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C5-C8 hydrocarbon.
[00111] In some implementations, the solvent used for the solvent deasphalting
comprises a
mixture of C5-C8 hydrocarbons.
[00112] In some implementations, separating the slurry stream comprises
vaporizing the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and subjecting the vapour/solid mixture to inertial
separation.
[00113] In some implementations, converting the treated asphaltene particulate
product
comprises:
extruding the treated asphaltene particulate product to produce extruded
asphaltenes;
spinning the extruded asphaltenes into a continuous asphaltene thread;
carbonizing the asphaltene thread by heat treatment to produce a carbonized
carbon
fiber; and
conditioning the carbonized carbon fiber to produce the carbon fiber product.
14
Date Recue/Date Received 2022-09-13
[00114] In some implementations, the process comprises stabilizing the
asphaltene thread by
heat treatment to produce a stabilized asphaltene thread and carbonizing the
stabilized
asphaltene thread to produce the carbonized carbon fiber.
[00115] In some implementations, the stabilizing heat treatment is performed
at about 175 C
to about 290 C (about 350 F to about 550 F) for up to 1 hour.
[00116] In some implementations, the carbonizing heat treatment is performed
at about 995 C
to about 2000 C (about 1823 F to about 3632 F) for up to 1 hour.
[00117] In some implementations, the process further comprises, before
producing the
extruded asphaltenes, a step of cleaning the treated asphaltene particulate
product to remove
undesirable solids and/or light hydrocarbons.
[00118] In some implementations, cleaning comprises filtering the undesirable
solids, vacuum
distillation to remove the light hydrocarbons and/or a secondary deasphalting.
[00119] In some implementations, the secondary deasphalting comprises
deasphalting using
a saturated or unsaturated cyclic or heterocyclic hydrocarbon solvent.
[00120] In some implementations, the saturated or unsaturated cyclic or
heterocyclic
hydrocarbon solvent is one or more of toluene, xylene, benzene,
tetrahydrofuran,
cyclohexanone, quinoline or pyridine.
[00121] In some implementations, the heterocyclic hydrocarbon solvent is
tetrahydrofuran.
[00122] In some implementations, spinning comprises melt spinning.
[00123] In some implementations, conditioning comprises surface treating and
sizing the
carbonized carbon fiber to create the carbon fiber product.
[00124] In some implementations, the carbon fiber product has a tensile
strength of at least 3
GPa and a Young's modulus of at least 400 GPa.
[00125] In some implementations, conditioning comprises graphitization of the
carbonized
carbon fiber to form a graphitized carbon fiber, and surface treating and
sizing the graphitized
carbon fiber to create the carbon fiber product.
Date Recue/Date Received 2022-09-13
[00126] In some implementations, graphitization comprises heating the carbon
fiber to over
3000 C (5432 F).
[00127] In some implementations, the carbon fiber product has a tensile
strength of at least
2.5 GPa and a Young's modulus of at least 500 GPa.
[00128] In some implementations, the present technology relates to a system
for producing a
carbon fiber product, comprising:
a chemical treatment unit configured to treat a solid asphaltene particulate
material
with at least one chemical agent to produce a chemically treated asphaltene
particulate product, where the chemical agent comprises a Lewis acid, a
reducing
agent, an oxidizing agent or any mixture thereof;
conversion units to convert the chemically treated asphaltene particulate
product into
the carbon fiber product.
[00129] In some implementations, the chemical treatment unit is provided with
a heating
system to treat the solid asphaltene particulate stream with the chemical
agent under heating.
[00130] In some implementations, the chemical treatment unit is configured to
enable
sparging when the solid asphaltene particulate stream is treated with the
chemical agent.
[00131] In some implementations, the solid asphaltene particulate material
comprises 95 wt
% or more C5+ asphaltenes.
[00132] In some implementations, the chemical agent comprises one or more
oxidizing
agents.
[00133] In some implementations, the oxidizing agent is at least one compound
comprising
bromine, silver, chromium, manganese, and/or oxygen, or is a peroxide.
[00134] In some implementations, the chemical agent comprises KMn04, H202 or a
combination thereof.
16
Date Recue/Date Received 2022-09-13
[00135] In some implementations, the chemical agent comprises a Lewis acid
which is
aluminum chloride, boron chloride, iron chloride, tin chloride, titanium
chloride, aluminum
bromide, boron bromide, iron bromide, tin bromide, titanium bromide, or any
mixture thereof.
[00136] In some implementations, the chemical agent comprises one or more
reducing
agents.
[00137] In some implementations, the reducing agent is at least one compound
comprising
lithium, sodium, potassium, magnesium, aluminum, or zinc.
[00138] In some implementations, the chemical agent comprises one or more
reducing agents
selected from sodium hydroxide, potassium hydroxide, a molten sodium salt, a
molten
potassium salt, urea, NaBI-14, and any mixture thereof.
[00139] In some implementations, the system further comprises:
a solvent deasphalting separator configured to contact a heavy hydrocarbon
feedstock stream with a solvent to precipitate asphaltenes and form solid
asphaltene
precipitates, the solvent deasphalting separator producing a solvent-diluted
deasphalted oil stream comprising at least a portion of the solvent and a
slurry stream
comprising the asphaltene precipitates and residual solvent;
an inertial separation unit in fluid communication with the solvent
deasphalting
separator, the inertial separation unit being configured to separate the
slurry stream
solids to produce the solid asphaltene particulate material and a recovered
solvent
stream.
[00140] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
[00141] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C3-C8 hydrocarbon.
[00142] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C5-C8 hydrocarbon.
17
Date Recue/Date Received 2022-09-13
[00143] In some implementations, the solvent used in the solvent deasphalting
separator
comprises a mixture of C5-C8 hydrocarbons.
[00144] In some implementations, the inertial separation unit is configured to
vaporize the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and to separate the vapour/solid mixture to recover
the solid
asphaltene particulate material.
[00145] In some implementations, the conversion units comprise:
an extruding unit configured to extrude the chemically treated asphaltene
particulate
product to produce extruded asphaltenes;
a spinning unit configured to spin the extruded asphaltenes into a continuous
asphaltene thread;
a carbonization unit configured to carbonize the asphaltene thread to produce
a
carbonized carbon fiber;
a surface and sizing treatment unit configured to surface treat and size the
carbonized
carbon fiber or a carbon fiber derived from the carbonized carbon fiber to
produce the
carbon fiber product.
[00146] In some implementations, the system further comprises a stabilization
unit between
the spinning unit and the carbonization unit configured to stabilize the
asphaltene thread to
produce a stabilized asphaltene thread and wherein the carbonization unit is
configured to
carbonize the stabilized asphaltene thread to produce the carbonized carbon
fiber.
[00147] In some implementations, the stabilization unit is operated at about
175 C to about
290 C (about 350 F to about 550 F) for up to 1 hour to stabilize the
asphaltene thread.
[00148] In some implementations, the carbonization unit is operated at about
995 C to about
2000 C (about 1823 F to about 3632 F) for up to 1 hour to carbonize the
asphaltene thread.
18
Date Recue/Date Received 2022-09-13
[00149] In some implementations, the system further comprises a cleaning unit
before the
extrusion unit, configured to remove undesirable solids and/or light
hydrocarbons from the
treated asphaltene particulate stream.
[00150] In some implementations, the cleaning unit comprises a filter to
remove the
undesirable solids, a vacuum distillation to remove the light hydrocarbons
and/or a secondary
deasphalting unit.
[00151] In some implementations, the secondary deasphalting unit isoperated
with a
saturated or unsaturated cyclic or heterocyclic hydrocarbon solvent.
[00152] In some implementations, the saturated or unsaturated cyclic or
heterocyclic
hydrocarbon solvent is one or more of toluene, xylene, benzene,
tetrahydrofuran,
cyclohexanone, quinoline or pyridine.
[00153] In some implementations, the heterocyclic hydrocarbon solvent is
tetrahydrofuran.
[00154] In some implementations, the spinning unit comprises a melt spinning
unit.
[00155] In some implementations, the system further comprises a graphitization
unit after the
carbonization unit configured to heat the carbonized carbon fiber and produce
the derived
carbon fiber in the form of a graphitized carbon fiber.
[00156] In some implementations, the graphitization unit is operated at a
temperature over
3000 C (5432 F).
[00157] In some implementations, the present technology also relates to a
process for
producing an activated carbon fiber, comprising:
extruding a solid asphaltene particulate material to produce extruded
asphaltenes;
spinning the extruded asphaltenes into a continuous asphaltene thread;
carbonizing the asphaltene thread by heat treatment to produce a carbonized
carbon
fiber;
activating the carbon fiber to produce an activated carbon fiber.
19
Date Recue/Date Received 2022-09-13
[00158] In some implementations, activating comprises steam activation.
[00159] In some implementations, steam activation is performed at a steam
temperature of
about 800 C to about 900 C.
[00160] In some implementations, steam activation is performed at a steam rate
of about 100
g/hr to about 200 g/hr.
[00161] In some implementations, the activated carbon fiber has a BET surface
area of at
least 500 m2/g.
[00162] In some implementations, the activated carbon fiber has a BET surface
area of at
least 1000 m2/g.
[00163] In some implementations, the carbonizing heat treatment is performed
at about 995 C
to about 2000 C (about 1823 F to about 3632 F) for up to 1 hour.
[00164] In some implementations, the process further comprises stabilizing the
asphaltene
thread by heat treatment to produce a stabilized asphaltene thread and
carbonizing the
stabilized asphaltene thread to produce the carbonized carbon fiber.
[00165] In some implementations, the stabilizing heat treatment is performed
at about 175 C
to about 290 C (about 350 F to about 550 F) for up to 1 hour.
[00166] In some implementations, the process further comprises graphitization
of the
carbonized carbon fiber to form a graphitized carbon fiber, and wherein
activating comprises
activating the graphitized carbon fiber to produce the activated carbon fiber.
[00167] In some implementations, graphitization comprises heating the
carbonized carbon
fiber to over 3000 C (5432 F).
[00168] In some implementations, the process further comprises:
thermally treating a heavy hydrocarbon feedstock to produce a lighter
hydrocarbon
stream and a heavier hydrocarbon stream;
Date Recue/Date Received 2022-09-13
solvent deasphalting the heavier hydrocarbon stream with a solvent to
precipitate
asphaltenes and form solid asphaltene precipitates and produce deasphalted
oil;
separating the deasphalted oil from the solid asphaltene precipitates to
produce a
solvent-diluted deasphalted oil stream comprising at least a portion of the
solvent and
a slurry stream comprising the asphaltene precipitates and residual solvent;
separating the slurry stream to produce the solid asphaltene particulate
material.
[00169] In some implementations, thermally treating the hydrocarbon feedstock
is performed
at a temperature ranging from about 370 C (700 F) to about 420 C (790 F) for a
residence
time ranging from 1 minute to 7 hours.
[00170] In some implementations, the hydrocarbon feedstock comprises a bitumen-
containing
feedstock derived from a surface mining operation or an in situ extraction
operation.
[00171] In some implementations, the solvent used for the solvent deasphalting
comprises at
least one C3-C8 hydrocarbon.
[00172] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C5-C8 hydrocarbon.
[00173] In some implementations, the solvent used in the solvent deasphalting
separator
comprises a mixture of C5-C8 hydrocarbons.
[00174] In some implementations, separating the slurry stream comprises
vaporizing the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and subjecting the vapour/solid mixture to inertial
separation.
[00175] In some implementations, the process further comprises separating
insolubles from
the solid asphaltene particulate material, wherein separating the insolubles
comprises
combining the solid asphaltene particulate material with an insolubles-
producing solvent to
produce the insolubles, and removing the insolubles from the solid asphaltene
particulate
material.
21
Date Recue/Date Received 2022-09-13
[00176] In some implementations, the insolubles-producing solvent is a
saturated or
unsaturated cyclic or heterocyclic hydrocarbon.
[00177] In some implementations, the insolubles-producing solvent is one or
more of toluene,
xylene, benzene, tetrahydrofuran, cyclohexanone, quinoline or pyridine.
[00178] In some implementations, the process further comprises surface
treating and sizing
the activated carbon fiber to create a carbon fiber product.
[00179] In some implementations, the carbon fiber product has a tensile
strength of at least 1
GPa and a Young's modulus of at least 100 GPa.
[00180] In some implementations, the present technology further relates to a
system for
producing an activated carbon fiber, comprising:
an extruding unit configured to extrude a solid asphaltene particulate
material to
produce extruded asphaltenes;
a spinning unit configured to spin the extruded asphaltenes into a continuous
asphaltene thread;
a carbonization unit configured to carbonize the asphaltene thread to produce
a
carbonized carbon fiber;
an activating unit configured to activate the carbon fiber and produce an
activated
carbon fiber.
[00181] In some implementations, the activation unit comprises a steam
activation unit.
[00182] In some implementations, the steam activation unit is operated at a
steam
temperature of about 800 C to about 900 C.
[00183] In some implementations, the steam activation unit is operated at a
steam rate of
about 100 g/hr to about 200 g/hr.
[00184] In some implementations, the carbonization unit is operated at about
995 C to about
2000 C (about 1823 F to about 3632 F) for up to 1 hour.
22
Date Recue/Date Received 2022-09-13
[00185] In some implementations, the system further comprises a stabilization
unit before the
carbonization unit configured to stabilize the asphaltene thread by heat
treatment to produce
a stabilized asphaltene thread.
[00186] In some implementations, the stabilizing unit is operated at about 175
C to about
290 C (about 350 F to about 550 F) for up to 1 hour.
[00187] In some implementations, the system further comprises a graphitization
unit
configured to heat the carbonized carbon fiber and produce a graphitized
carbon fiber, and
wherein the graphitized carbon fiber is activated into the activation unit.
[00188] In some implementations, the graphitization unit is operated at a
temperature over
3000 C (5432 F).
[00189] In some implementations, the system further comprises:
a thermal reactor configured to receive a heavy hydrocarbon feedstock and
produce
a lighter hydrocarbon stream and a heavier hydrocarbon stream;
a solvent deasphalting separator in fluid communication with the thermal
reactor and
configured to contact the heavier hydrocarbon stream with a solvent to
precipitate
asphaltenes and form solid asphaltene precipitates, the solvent deasphalting
separator producing a solvent-diluted deasphalted oil stream comprising at
least a
portion of the solvent and a slurry stream comprising the asphaltene
precipitates and
residual solvent;
an inertial separation unit in fluid communication with the solvent
deasphalting
separator, the inertial separation unit being configured to separate the
slurry stream
solids to produce the solid asphaltene particulate material and a recovered
solvent
stream;
[00190] In some implementations, the thermal reactor is configured to operate
at a
temperature about 370 C (700 F) to about 420 C (790 F) for a residence time
ranging from 1
minute to 7 hours.
23
Date Recue/Date Received 2022-09-13
[00191] In some implementations, the heavy hydrocarbon feedstock comprises a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
[00192] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one of C3-C8 hydrocarbon.
[00193] In some implementations, the solvent used in the solvent deasphalting
separator
comprises at least one C5-C8 hydrocarbon.
[00194] In some implementations, the solvent used in the solvent deasphalting
separator
comprises a mixture of C5-C8 hydrocarbons.
[00195] In some implementations, the inertial separation unit is configured to
vaporize the
residual solvent to produce a vapour/solid mixture comprising vaporized
solvent and the solid
asphaltene precipitates, and to separate the vapour/solid mixture to recover
the solid
asphaltene particulate stream.
[00196] In some implementations, the system further comprises an insolubles
separation unit
configured to contact the solid asphaltene particulate material with an
insolubles-producing
solvent and to separate the insolubles from the solid asphaltene particulate
material.
[00197] In some implementations, the insolubles-producing solvent is a
saturated or
unsaturated cyclic or heterocyclic hydrocarbon.
[00198] In some implementations, the insolubles-producing solvent is one or
more of toluene,
xylene, benzene, tetrahydrofuran, cyclohexanone, quinoline or pyridine.
[00199] In some implementations, the system further comprises a surface and
sizing
treatment unit configured to surface treat and size the activated carbon fiber
to produce a
carbon fiber product.
[00200] In some implementations, the carbon fiber product has a tensile
strength of at least 1
GPa and a Young's modulus of at least 100 GPa.
24
Date Recue/Date Received 2022-09-13
BRIEF DESCRIPTION OF DRAWINGS
[00201] FIG. 1 represents a flow diagram of the process for obtaining a carbon
fiber from a
heavy hydrocarbon feedstock according to a first implementation.
[00202] FIG. 2 represents a flow diagram of the process for obtaining a carbon
fiber from a
heavy hydrocarbon feedstock according to another implementation.
[00203] FIG. 3 represents a flow diagram of the process for obtaining a carbon
fiber from a
heavy hydrocarbon feedstock according to yet another implementation.
[00204] Fig. 4 represents a flow diagram of the process for obtaining a carbon
fiber from a
heavy hydrocarbon feedstock according to a further implementation.
DETAILED DESCRIPTION
[00205] The present technology relates to a process for obtaining a carbon
fiber product from
a heavy hydrocarbon feedstock containing asphaltenes involving various
asphaltene
treatments to arrive at the final carbon fiber product. In some
implementations, the treatments
can include addition of polymers or chemical agents at certain steps of the
process to allow
obtaining a variety of carbon fiber products. Other treatments can involve an
activation step
whereby an activated carbon fiber can be produced. Depending on the
treatment(s) to which
are subjected the asphaltenes, one can obtain general purpose carbon fibers,
mid-
performance carbon fibers, or high-performance carbon fibers, as will be
detailed below.
Definitions
[00206] All technical and scientific terms used herein have the same meaning
as commonly
understood by one ordinary skilled in the art to which the present technology
pertains. For
convenience, the meaning of certain terms and phrases used herein are provided
below.
[00207] To the extent the definitions of terms in the publications, patents,
and patent
applications incorporated herein by reference are contrary to the definitions
set forth in this
specification, the definitions in this specification control.
Date Recue/Date Received 2022-09-13
[00208] The terminology used herein is for the purpose of describing
particular
implementations only and is not intended to be limiting. It should be noted
that, the singular
forms "a", "an", and "the" include plural forms as well, unless the content
clearly dictates
otherwise. To the extent that the terms "including", "includes", "having",
"has", "with", or
variants thereof are used in either the detailed description and/or the
claims, such terms are
intended to be inclusive in a manner similar to the term "comprising".
[00209] The term "about" means within an acceptable error range for the
particular value as
determined by one of ordinary skill in the art, which will depend in part on
how the value is
measured or determined, i.e., the limitations of the measurement system. For
example, "about"
can mean within 1 or more than 1 standard deviation, per the practice in the
art. Alternatively,
"about" can mean a range of up to 20%, preferably up to 10%, more preferably
up to 5%, and
more preferably still up to 1% of a given value. Alternatively, particularly
with respect to
biological systems or processes, the term can mean within an order of
magnitude, preferably
within 5-fold, and more preferably within 2-fold, of a value. Where particular
values are
described in the application and claims, unless otherwise stated the term
"about" meaning
within an acceptable error range for the particular value should be assumed.
[00210] Carbon fiber - Fiber containing at least 92 wt % carbon. The carbon
fiber that can be
produced according to the present process can be any carbon fiber from the
main four classes
of carbon fibers as classified according to the tensile modulus of the fiber:
- standard modulus carbon fiber (at least 92 wt % carbon)
- intermediate modulus carbon fiber (92-95 wt % carbon)
- high modulus carbon fiber (95-99 wt % carbon)
- ultrahigh modulus carbon fiber (99 wt % and more carbon) that includes
graphite fiber.
[00211] General purpose carbon fiber - Carbon fibers that have relatively low
tensile strength
(less than 1 GPa) and low Young's modulus (less than 100 GPa) respectively.
Isotropic-pitch-
based carbon fibers belong to this grade and are used in applications that
benefit from their
low weight and bulkiness, e.g., thermal insulation for a high-temperature
furnace, cement
reinforcement and activated carbon fiber applications.
26
Date Recue/Date Received 2022-09-13
[00212] Mid-performance carbon fiber - Carbon fibers that nominally have
tensile strength in
the range from 1 to 2.5 GPa and Young's modulus in the range from 100 to 500
GPa.
[00213] High-performance carbon fiber - Carbon fibers that have at least one
of relatively high
tensile strength and high Young's modulus. For instance, a high-performance
carbon fiber can
present a tensile strength greater than 2.5 GPa with a Young's modulus around
200 to 300
GPa or can present a high Young's modulus, i.e., greater than 500 GPa with a
tensile strength
in the range 2.5-4.5 GPa. This quality of carbon fiber is anisotropic in
nature due to presence
of mesophase material.
[00214] Graphene - Graphene is an atomic-scale hexagonal lattice made of a
single layer of
carbon atoms. It is the basic structural element of many other allotropes of
carbon, such as
graphite, diamond, charcoal, carbon nanotubes and fullerenes.
[00215] Insolubles ¨ Material that precipitates into or remains in the solid
form when mixed
with a solvent.
[00216] Mesophase ¨ A phase of matter intermediate between a liquid and solid,
referred to
as liquid crystals.
[00217] Non-Newtonian fluid ¨ A fluid having a viscosity (the gradual
deformation by shear or
tensile stresses) dependent on shear rate or shear rate history. A Non-
Newtonian fluid's
viscosity can change when under force to either more liquid or more solid.
[00218] Pipelineable crude ¨ Heavy hydrocarbon with API less than or equal to
19 (density >
920 kg/m3), and/or more than 300 cst that requires some processing to meet
pipeline
specifications of greater than API 19 (density < 920 kg/m3), viscosity less
than 300 cSt at
reference temperature, sediment and water less than 0.4 wt% and olefins less
than 1 wt% or
non-detectable by the measurement tool used by the transporter.
[00219] Tensile strength ¨ Measure of the amount of force with which a fiber
can be pulled
before it breaks.
[00220] Young's modulus - Measure of a material's stiffness defined as the
axial stress divided
by the axial strain. The higher the modulus, the stiffer the material (i.e.,
the greater the stress
necessary to cause deformation).
27
Date Recue/Date Received 2022-09-13
[00221] BET surface area ¨ Surface area measured according to the
Brunauer¨Emmett¨
Teller (BET) principle involving physical adsorption of gas molecules
(generally nitrogen gas
N2) on a solid surface.
[00222] Some implementations of the process will now be described by referring
to the
Figures.
[00223] Figure 1 represents a process 10 for preparing a carbon fiber product
140 from a
heavy hydrocarbon feedstock 5, involving various treatment steps that will be
detailed below.
In some implementations, the heavy hydrocarbon feedstock 5 can include a
bitumen-
containing feedstock derived from a surface mining operation or an in situ
extraction operation.
In some implementations, the heavy hydrocarbon feedstock can derive from a
SAGD (steam
assisted gravity drainage) process. In other implementations, the heavy
hydrocarbon
feedstock can derive from a solvent-based or solvent-enhanced in situ
hydrocarbon recovery
process.
[00224] In the present description, reference is made to "heavy hydrocarbon
feedstock" as the
product that is used for preparing the carbon fiber according to the present
technology. It is to
be noted that the process described herein can be implemented with any type of
heavy
hydrocarbon-containing feedstock (also referred to as "heavy oil feedstock")
recovered from a
subsurface extraction operation or from a surface mining process or can be a
feedstock
derived from the recovered heavy oil. The feedstock derived from the recovered
heavy oil can
include any product that is obtained downstream of extraction, which contains
asphaltenes. In
some implementations, the heavy hydrocarbon feedstock can include bitumen
(e.g., from oil
sands). In some implementations, the techniques described herein can employ a
bitumen
product, atmospheric bottoms or vacuum tower bottoms.
[00225] In some implementations, the heavy hydrocarbon feedstock can include
both heavy
and light hydrocarbon fractions. The heavy hydrocarbon feedstock includes
asphaltenes. In
some implementations, the heavy hydrocarbon feedstock includes "native"
asphaltenes,
meaning that the asphaltenes in the feedstock are substantially asphaltenes in
the form that
were in the ground before extraction therefrom. In some implementations,
"native" asphaltenes
thus includes any asphaltenes that have not been heated or converted
chemically and/or
thermally. One can also refer to "unspoiled" asphaltenes. In some
implementations, the heavy
28
Date Recue/Date Received 2022-09-13
hydrocarbon feedstock can include a low mineral solids content. In other
implementations, the
heavy hydrocarbon feedstock can include higher mineral solids and/or solid
particles content.
The bitumen feedstock can include various non-hydrocarbon compounds (e.g.,
sulfur, heavy
metals, etc.) that are often found in bitumen and may be associated with
certain fractions or
solubility classes of bitumen. It should also be noted that the bitumen
feedstock can in some
cases be a blend of different hydrocarbon streams.
[00226] Returning to the implementations presented in Figure 1, the heavy
hydrocarbon
feedstock stream 5 is directly sent to a solvent deasphalting apparatus (SDA)
50 where the
heavy hydrocarbon feedstock stream is contacted with a deasphalting solvent 63
to precipitate
asphaltenes from the feedstock and produce a solvent-diluted deasphalted oil
stream 57 and
a solid asphaltene precipitates-containing stream 53, which also contains
residual solvent.
The solvent-diluted deasphalted oil 57 can be sent to a separate treatment
plant for being
upgraded, such as a Fluid Catalytic Cracking Unit (FCCU) for instance (not
shown in the figure)
or any other upgrading facility (e.g., using ionic liquids). An example of a
solid-liquid solvent
separation process and system that can be used for step 50 can include the one
described in
US patent 9,976,093 and Canadian patent 2,844,000. The deasphalting solvent
can include
any known solvent capable of precipitating asphaltenes from a heavy
hydrocarbon feedstock.
In some implementations, the deasphalting solvent can be a pure hydrocarbon
component in
the range of C3 to Cg. Hence, in some implementations, the deasphalting
solvent can include
propane, butane or a mixture thereof. In some implementations, a pure
hydrocarbon
component in the range of C3 to C8 can be used as the deasphalting solvent. In
other
implementations, the deasphalting solvent can be a mixture of C3 to C8
hydrocarbons, or a
mixture of C5 to C8 hydrocarbons, e.g., extracted from readily available
natural gas condensate
or diluent that comes in with the heavy crude feed. In some implementations,
the SDA can be
operated to reject as much non-asphaltene crude as possible, creating a 95 wt%
or more
concentrated C5+ asphaltene stream that can be processed in the next steps to
obtain the
final carbon fiber product. In some implementations, operating the SDA to
obtain such a
concentrated C5+ asphaltene stream can allow minimizing the downstream process
steps
required for removing remaining non-asphaltene molecules from the crude
feedstock. CA
2,844,000 mentioned above describes conditions that can be used for operating
the SDA.
29
Date Recue/Date Received 2022-09-13
[00227] Stream 53 exiting the SDA 50 can be in the form of a slurry containing
entrained solid
asphaltene precipitates in a solvent liquid phase. In some implementations,
stream 53 can be
reduced in pressure to flash the solvent to create a vapor/solid mixture as a
slurry or
suspension before entering the inertial separation unit (ISU) 60, where a
solid/vapour
separation can then be performed. In the ISU 60, the solvent vapour is
condensed and can be
returned to the SDA 50 as recovered solvent stream 63, which can then be
reused in the SDA
50. Although, Figure 1 only shows that deasphalting solvent is provided to the
SDA 50 as
recovered stream 63, make-up deasphalting solvent can further be provided to
the SDA, as
required. In ISU 60, the slurry stream 53 is thus separated to produce a solid
asphaltene
particulate stream 61 that can be further processed in various steps to obtain
the final carbon
fiber product 140.
[00228] In some implementations, the solid asphaltene particulate stream 61
can be directly
sent to the next process step, which includes extrusion of the solid
asphaltene particulate
material in unit 80. In an optional implementation, the solid asphaltene
particulate stream 61
exiting the ISU 60, can be further treated in unit 65 before the next
extrusion step. Hence, in
some implementations, the process can involve sending the solid asphaltene
particulate
stream 61 to unit 65 where a further treatment is performed to separate any
undesirable solids
(also referred to as "insolubles") that hinder the generation of carbon fiber,
from the solid
asphaltene particulate stream 61. The undesirable solids can be removed as
stream 64 and a
cleaner asphaltene particulate-containing stream 67 can be produced. The
undesirable solids
that are removed in unit 65 can contain various solid particles, inorganic
material, and/or dirt
that was present in the feedstock. In some implementations, unit 65 can
contain a second
solvent deasphalting step using organic solvents that adsorb heavier molecules
than the
solvent that is used in the SDA 50. The solvents that can be used to reject
the heaviest, most
undesirable solids in the solid asphaltene particulate stream 61 can include
saturated or
unsaturated cyclic or heterocyclic hydrocarbon based compounds, such as
toluene, xylene,
benzene, tetrahydrofuran, cyclohexanone, quinoline and pyridine among others.
In some
implementations, vacuum distillation can also be used in unit 65, alone or in
combination with
the second deasphalting step, to remove any remaining lighter molecules that
could create
voids in the carbon fiber. Any lighter material evolved in the vacuum
distillation or similar
process, including the saturated or unsaturated cyclic or heterocyclic
hydrocarbon based
solvent, will end up as stream 66. In addition, sparging can be considered
within unit 65 to
Date Recue/Date Received 2022-09-13
produce more mesophase material by removing lighter components and altering
the
orientation of the carbon molecules to promote high-performance carbon fiber
in stream 140.
Sparging is a process similar to air blowing, and for carbon fiber, sparging
is generally
conducted with inert nitrogen instead of air.
[00229] The solid asphaltene particulate stream 61 or 67 can then enter an
extruder 70 where
pressure can be applied to the solid asphaltenes to remove any remaining
entrained solvent.
In some implementations, the solid asphaltene particulate stream 61 or 67 can
be submitted
to a crushing step before extrusion in extruder 70 (not shown in the Figures).
Crushing can be
performed in a regular breaker, rotary breaker, or a direct-drive crusher. In
some
implementations, crushing can be performed to obtain small particulate size,
which can then
promote interaction with any additives that may be used in the process. With
smaller particle
size, any additive used can surround the particles readily. In some
implementations, crushing
can result in solid asphaltene particles of size in the range from about 10 pm
to about 100 pm.
In some implementations, a crusher is used before the extruder, but it could
also be possible,
in some implementations, to just have a crusher to grind up solid asphaltenes
fine enough for
the next spinning treatment step.
[00230] In some implementations, the extruder 70 is heated to a temperature in
the 200-350 C
range to create conditions to provide continuous flow as a Non-Newtonian fluid
through and
out of the equipment. The solvent removed in unit 70 can be returned to the
SDA unit as stream
73. Some of the generated asphaltene extrudate can be segregated and sent to
the solid fuels
market, as stream 71, if the market for carbon fiber is saturated or not
economic. In another
implementation, material in stream 71 can be sent for processing to become
activated carbon.
The majority of the extruded asphaltenes can leave the extruding unit 70 as
stream 75. In the
next step, the extruded material can be treated in a spinning unit 80, where
"green" carbon
fiber can be produced as stream 85. In some implementations, a single unit can
be used
wherein extrusion and spinning can be performed. "Green" carbon fiber is a
term used for
hydrocarbon crude derived fiber that has yet to be oxidized or carbonized.
Green carbon fiber
can be extremely fragile. The spinning of the extruded asphaltenes resulting
in the "green"
carbon fiber can be accomplished by either melt, wet or jet spinning. In some
implementations,
melt spinning is preferably used. After spinning, the green fiber made of a
continuous
asphaltene thread can have a diameter that is less than 25 pm, or less than 20
pm, or even
31
Date Recue/Date Received 2022-09-13
less than 15 pm. In some implementations, the diameter of the green fiber can
be less than 10
pm.
[00231] Then, the continuous asphaltene thread or "green" fiber 85, can be
stabilized in unit
90. In some implementations, stabilization can be accomplished by heating. For
instance, the
green fibers can be heated in a forced air environment to provide sufficient
fresh oxygen to the
fiber surfaces. In some implementations, the stabilizing heat treatment can be
performed at
temperatures in the range of about 200 to about 300 C. Heating causes the
spun
fibers/threads to pick up oxygen molecules on their surfaces to prevent the
onset of inter-fiber
coalescence or melting and to promote good carbon yield in the following
carbonization step.
Stabilization can take between a few minutes up to an hour or two. In some
implementations,
the stabilizing heat treatment can be performed at about 175 C to about 290 C
(about 350 F
to about 550 F) for up to 1 hour.
[00232] The stabilized fiber/thread exits the stabilizing unit 90 as stream
95, and can then be
subjected to carbonization in unit 100. Carbonization can be performed under
an inert
environment (no oxygen) by heating the stabilized fiber uniformly up to
approximately 1000 C.
In some implementations, the carbonization can be performed at higher
temperatures and up
to about 2000 C, to improve both the fiber strength and Young's modulus. The
carbonizing
step can take between a minute to up to an hour or two depending on the
desired final
properties. In some implementations, the carbonizing heat treatment can be
performed at
about 995 C to about 2000 C (about 1823 F to about 3632 F) for up to 1 hour.
Performing the
carbonization under an inert environment, i.e., without oxygen, can prevent
the fibers from
burning in the very high temperatures. As the fibers are heated, they can
begin to lose their
non-carbon atoms, plus a few carbon atoms, in the form of various gases
including water
vapor, ammonia, carbon monoxide, carbon dioxide, hydrogen, nitrogen, sulfur,
evolved metals
such as nickel and vanadium and others. As the non-carbon atoms are expelled,
the remaining
carbon atoms can form tightly bonded carbon crystals that are aligned more or
less parallel to
the long axis of the fiber. In other implementations, the carbonization can be
performed using
two furnaces operating at two different temperatures to better control the
rate of heating during
carbonization.
[00233] The carbonized fiber that leaves the carbonization unit 100 can then
be subjected to
various treatments to produce the final carbon fiber product 140.
32
Date Recue/Date Received 2022-09-13
[00234] In one implementation, the carbonized fiber stream 101 exiting unit
100 can directly
be sent to a surface treatment and sizing in unit 110. Surface treatment and
sizing methods
that can be used can include acid oxidation, resin addition, plasma treatment,
rare earth
treatment, and/or gamma irradiation. Surface treatment can lead to improved
composite
properties due to the conditions of improved surface area of the fiber
surface, chemical
bonding and adhesion between fiber and matrix. Surface treating and sizing is
typically used,
since after carbonizing, the fibers have a surface that does not bond well
with epoxies and
other materials used in composite materials. To give the fibers better bonding
properties, their
surface can be slightly oxidized. The addition of oxygen atoms to the surface
can provide better
chemical bonding properties and also can etch and roughen the surface for
better mechanical
bonding properties. Oxidation can be achieved by immersing the fibers in
various gases such
as air, carbon dioxide, or ozone; or in various liquids such as sodium
hypochlorite or nitric acid.
The fibers can also be coated electrolytically by making the fibers the
positive terminal in a
bath filled with various electrically conductive materials. The surface
treatment process can be
controlled to avoid forming tiny surface defects, such as pits, which could
cause fiber failure.
In some implementations, the fibers are surface treated and then coated
(sizing step) to protect
them from damage during winding or weaving. Coating materials are chosen to be
compatible
with the adhesive used to form composite materials. Typical coating materials
include epoxy,
polyester, nylon, urethane, and others. The coated fibers are wound onto
cylinders called
bobbins. The bobbins are loaded into a spinning machine and the fibers are
twisted into yarns
of various sizes. It can be noted that when the process is performed without
the upstream
treatment in unit 65, the final carbon fiber product stream 140 can include a
general purpose
(GP) carbon fiber. Such a general purpose carbon fiber can have a tensile
strength of at least
100 MPa and a Young's modulus of at least 20 GPa. In other implementations,
the general
purpose carbon fiber can have a tensile strength of at least 150 MPa and a
Young's modulus
of at least 20 GPa. However, if the overall process is performed with the
upstream treatment
in unit 65, the resulting carbon fiber product stream 140 can be a carbon
fiber with increased
performance, such as a mid- or high-performance carbon fiber.
[00235] In another implementation, the carbonized fiber exiting unit 100 can
be subjected to
additional treatments before being sent to the surface treatment and sizing
unit 110, as also
shown in Figure 1. For instance, the carbonized fiber stream 103 can be sent
to a graphitization
unit 105 where the carbon fibers are graphitized at temperatures close to 3000
C or over, in
33
Date Recue/Date Received 2022-09-13
a non-oxygen environment, to further improve their Young's modulus. This step
can create
mid- and/or high-performance carbon fibers with tensile strength that can be
between 1-2.5
GPa for mid-performance and above 2.5 GPa for high-performance carbon fiber
and Young's
modulus between 100-500 GPa for mid-performance and above 200 GPa for high-
performance carbon fiber. The graphitized material leaving unit 105 as stream
108 can
produce a high-performance carbon fiber stream 140, after surface treatment is
performed in
unit 110. In another implementation, the graphitized material can leave unit
105 as stream 106
and be sent to an activation unit 107 before the final surface and sizing
treatment. In unit 107,
the graphitized carbon fiber can thus be treated to create an activated carbon
fiber 109 to
provide additional properties to the final carbon fiber product 140. In some
implementations,
activation can be performed with steam. Hence, steam can be introduced into
the activation
chamber where it can interact with the carbon fiber. In some implementations,
activation with
steam can be performed for up to about 1 hour, and usually for a maximum of
about 2 hours.
In some implementations, activation can be performed at a steam temperature of
about 800
C to about 900 C and a steam rate of about 100 g/hr to about 200 g/hr. In some
implementations, the residence time in the activation unit can be from about
30 minutes to
about 2 hours, or from about 30 minutes to about 90 minutes or from about 30
minutes to about
1 hour or from about 1 hour to about 90 minutes. In some implementations, the
residence time
in the activation unit can be about 1 hour. Creating an activated carbon fiber
can be interesting
compared to an activated carbon powder or briquette for some applications. For
instance, an
activated carbon fiber can be molded to a desired shape for a specific
application. Molded
activated carbon fiber pieces can be used to produce all-in-one filters, while
a housing is
required for filters using activated carbon powder. Producing activated carbon
fibers can thus
open opportunities at least for carbon-based filters. In some implementations,
the activated
carbon fiber can present a BET surface area of at least 500 m2/g, or a BET
surface area of at
least 1000 m2/g in some implementations. The activated carbon fiber stream 109
leaving unit
107 can then be surface treated in unit 110 as explained above. The resulting
activated carbon
fiber product 140 can thus combine high performance and activation properties.
[00236] Another implementation of the present technology is shown in Figure 2.
In this
implementation, a polymer is combined with the solid asphaltene particulate
stream 61 at the
extrusion step 70 as will be detailed below. The heavy hydrocarbon feedstock
stream 5
containing native asphaltenes is sent to the SDA 50 where the heavy
hydrocarbon feedstock
34
Date Recue/Date Received 2022-09-13
stream is contacted with a deasphalting solvent 63 to precipitate asphaltenes
from the
feedstock and produce the solvent-diluted deasphalted oil stream 57 and the
solid asphaltene
precipitates-containing stream 53, which can also contain residual solvent.
The deasphalting
solvent is as described above and can include any known solvent capable of
precipitating
asphaltenes from a heavy hydrocarbon feedstock. In some implementations, the
deasphalting
solvent can be a pure hydrocarbon component in the range of C3 to C8,
preferably in the range
C5 to Cg. In some implementations, the deasphalting solvent can be a mixture
of C3 to C8
hydrocarbons, preferably a mixture of C5 to C8 hydrocarbons, e.g., extracted
from readily
available natural gas condensate or diluent that comes in with the heavy crude
feed.
[00237] In some implementations, stream 53 exiting the SDA 50, which is in the
form of a
slurry containing entrained solid asphaltene precipitates in a solvent liquid
phase, can be
reduced in pressure to flash the solvent to create a vapor/solid mixture as a
slurry or
suspension before entering the ISU 60, where a solid/vapour separation can
then be
performed. In the ISU 60, the solvent vapour is condensed and can be returned
to the SDA 50
as recovered solvent stream 63, which can then be reused in the SDA 50.
Although Figure 2
only shows that deasphalting solvent is provided to the SDA 50 as recovered
stream 63, make-
up deasphalting solvent can also be provided to the SDA, as required. In ISU
60, the slurry
stream 53 is thus separated to produce a solid asphaltene particulate stream
61 that can be
further processed in downstream steps to obtain the final carbon fiber product
140.
[00238] In some implementations, the solid asphaltene particulate stream 61 is
directly sent
to the next process step, which includes extrusion of the solid asphaltene
particulate material
in unit 80 in the presence of at least one polymer 7. However, other
implementations, stream
61 could be further treated in unit 65 to obtain stream 67, as described with
reference to Fig.
1 above. If this latter step is implemented, then asphaltene particulate-
containing stream 67 is
sent to the extrusion unit 70 to be extruded in the presence of polymer 7.
Addition of a polymer
at the extrusion step can allow to improve the modulus properties of the final
carbon fiber
product and also improve its impact resistance, while still retaining tensile
strength. In some
implementations, one can thus obtain carbon fibers that can compete with
polyacrylonitrile
(PAN) based carbon fibers, but also other materials such as steel and
aluminum, for instance.
In some implementations, the polymer material 7 can be a single polymer
(including a
copolymer) or a mixture of polymers (which can be homopolymer and/or
copolymers). In some
Date Recue/Date Received 2022-09-13
implementations, the polymer is at least one thermoplastic polymer. Examples
of polymers
that can be combined with the solid asphaltene particulate stream 61 can
include acrylic-based
polymers, polyolefins, polyesters, polystyrenes, polyvinylchlorides, and any
mixtures thereof.
In some implementations, the polymer 7 can be combined with the solid
asphaltene particulate
stream 61 in solid form. In some implementations, a mixing unit (not shown in
Figure 2) can
be used upstream of extrusion unit 70 to prepare a mixture of polymer-solid
asphaltene
particulates and then the mixture is sent to extrusion. In some
implementations, the polymer
and the solid asphaltene particulates can be mixed directly at the extrusion
step. In further
implementations, a crushing step can be carried out before extrusion to obtain
particles of both
the asphaltenes particulate and polymer of desired size for being extruded. In
some
implementations, the polymer can be used in an amount to allow generation of a
"green"
carbon fiber containing from about 30 wt% to about 70 wt% of polymer. In some
implementations, the amount of polymer is as low as possible in order to
retain a suitable
tensile strength in the final carbon fiber product. In some implementations,
the polymer can be
used in an amount to allow generation of a "green" carbon fiber containing
from about 30 wt%
to about 60 wt% of polymer, or from about 30 wt% to about 50 wt%, or from
about 30 wt% to
about 40 wt%. However, larger or smaller amounts can be used. One can select
the content
of polymer to be used as well as the nature of the polymer based on the
desired properties for
the final carbon fiber product. In extrusion unit 70, pressure can be applied
to the mixture
polymer-solid asphaltenes to remove any remaining entrained solvent. In some
implementations, the extruder 70 can be heated to a temperature in the range
of about 150 C
to about 350 C. In some implementations, the extruder can be heated at a
temperature in the
range of about 200 C to about 350 C. In some implementations, the extruder can
be heated
to a temperature in the range from about 150 C to about 300 C. The
temperature can be
adapted depending on the nature of the polymer being used and/or based on its
melting point
for instance. Heating can allow creation of conditions that provide for
continuous flow as a
Non-Newtonian fluid through and out of the equipment. The solvent removed in
unit 70 can be
returned to the SDA unit as stream 73. Some of the excess asphaltene extrudate
can be
directed to the solid fuels market, as stream 71, if the demand for polymer
carbon fiber is slow.
The extruded material containing polymer and asphaltenes leave the extruding
unit 70, as
stream 75. In the next step, the extruded material can be treated in the
spinning unit 80, where
"green" carbon fiber can be produced as stream 85. It is to be noted that in
some
implementations, extrusion and spinning can be performed in a single unit. The
spinning of the
36
Date Recue/Date Received 2022-09-13
extruded polymer-asphaltenes material resulting in the "green" carbon fiber
can be
accomplished by wet, jet or melt spinning. In some implementations, wet
spinning is used to
avoid or limit polymer decomposition or degradation that could be observed
with melt spinning.
After spinning, the green fiber made of a continuous polymer-asphaltene thread
can have a
diameter that is less than 15 pm. In some implementations, the diameter of the
green fiber can
be less than 10 pm. Then, the continuous polymer-asphaltene thread or "green"
fiber 85 can
be further processed as explain above with respect to Figure 1, to obtain the
final carbon fiber
product 140. Hence, the continuous polymer-asphaltene thread 85 can at least
be heat
stabilized/oxidized in unit 90 to form a stabilized polymer-asphaltene stream
95, which can
itself be carbonized in unit 100, and then, the carbonized material 101 can be
surface treated
in unit 110. In some implementations, the carbon fiber product 140, which is
obtained from the
continuous polymer-asphaltene thread after carbonization and surface treatment
can have a
tensile strength of at least 3.5 GPa and a Young's modulus of at least 250
GPa. In alternative
implementations, the carbonized material 103 can be subjected to a
graphitization step 105
before surface treatment in unit 110. In some implementations, an activation
step can also be
implemented, as explained above, between graphitization and surface treatment.
The carbon
fiber product 140 that is created after graphitization and surface treatment
can present a tensile
strength of at least 3 GPa and a Young's modulus of at least 350 GPa. The
implementation
represented in Figure 2 can thus lead to a mid- or high-performance carbon
fiber product 140,
which can optionally be activated.
[00239] In a further implementation of the present technology, as shown in
Figure 3, the solid
asphaltene particulate stream 61 can be subjected to a chemical treatment at
step 65' before
the extrusion step, as will be detailed below. The heavy hydrocarbon feedstock
stream 5
containing native asphaltenes is sent to the SDA 50 where the heavy
hydrocarbon feedstock
stream is contacted with a deasphalting solvent 63 to precipitate asphaltenes
from the
feedstock and produce the solvent-diluted deasphalted oil stream 57 and the
solid asphaltene
precipitates-containing stream 53, which also contains residual solvent. The
deasphalting
solvent is as described above with respect to Figures 1 and 2. In this
implementation, the solid
asphaltene particulate stream 61 is thus sent to a chemical treatment unit 65'
where it can be
contacted with at least one chemical agent 15 to produce a treated asphaltene
particulate
stream 67'. In some implementations, the chemical agent can be a Lewis acid, a
reducing
agent, an oxidizing agent or any mixture thereof. In some implementations, the
chemical
37
Date Recue/Date Received 2022-09-13
treatment can be performed using at least one Lewis acid, such as a weak Lewis
acid, as the
chemical agent. Using such Lewis acid chemical additive can promote the
formation of a
mesophase, which can, in turn, favor the creation of a final carbon fiber
product with higher
performance. The use of the Lewis acid(s), in this implementation, can even
allow formation
of the mesophase at temperatures that are low enough to avoid/limit the
formation of coke
particles, which can be beneficial for the whole process. In some
implementations, the Lewis
acid can be selected from aluminum chloride, boron chloride, iron chloride,
tin chloride,
titanium chloride, aluminum bromide, boron bromide, iron bromide, tin bromide,
titanium
bromide, or any mixture thereof. In some implementations, aluminum chloride
can be used as
the Lewis acid. In other implementations, the chemical agent can include an
oxidizing agent,
such as at least one compound including bromine, silver, chromium, manganese,
and/or
oxygen, or a peroxide. Examples of oxidizing agents that can be used include
KMnO4 and
H202 or a combination thereof. In other implementations, the chemical agent
can include a
reducing agent, which can optionally be used in combination with a Lewis acid
and/or an
oxidizing agent, as mentioned above. The use of a reducing agent can enable
removal of
certain impurities present in the solid asphaltene particulate stream 61, such
as sulfur and
metals for instance. Compounds including lithium, sodium, potassium,
magnesium, aluminum,
or zinc to name a few examples, are suitable reducing agents. In some
implementations, the
reducing agent can include sodium hydroxide, potassium hydroxide, a molten
sodium salt, a
molten potassium salt, urea, NaBF14 or any mixture thereof. In some
implementations, the
chemical agent can be used in an amount from about 3 to 8 wt% of the
asphaltene feedstock
up to about 20 to 25 wt% of the asphaltene feedstock. The amount of chemical
agent can be
selected depending on the complexity of the native asphaltenes and
temperatures used for
this processing step. In some implementations, the chemical agent can thus be
used in an
amount from about 3 wt% to about 25 wt%, or from about 3 wt% to about 20 wt%,
or from
about 8 wt% to about 25 wt%, or from about 8 wt% to about 20 wt%, or any value
included in
these ranges.
[00240] In some implementations, independently of the chemical agent(s) used,
the chemical
treatment in unit 35' can be performed under heating. For instance, the
chemical treatment
can be performed at a temperature of about 140 C to about 335 C. Furthermore,
in some
implementations, sparging can be considered within chemical treatment unit 65'
to produce
even more mesophase material by removing lighter components and altering the
orientation
38
Date Recue/Date Received 2022-09-13
of the carbon molecules to promote high-performance carbon fiber in stream
140. In some
implementations, sparging is conducted with inert nitrogen.
[00241] Hence, the solid asphaltene particulate stream 67' that exits unit 65'
can contain an
asphaltene material, which will promote the creation of a final carbon fiber
product with
enhanced properties, such as a higher performance. In some implementations,
the properties
of the final carbon fiber product 140 can be further enhanced by treating the
carbon fiber
material precursor 67' in an optional cleaning step that can be performed in
unit 62. This
"cleaning" step can be somewhat similar to the step performed in unit 65 as
described above
with respect to Figure 1. Hence, in some implementations, the solid asphaltene
particulate
stream 67' can be sent to unit 62 for removal of remaining undesirable solids
and/or light
hydrocarbons and produce a "cleaned" solid asphaltene particulate stream 68.
In some
implementations, the cleaning can involve filtering the undesirable solids,
vacuum distillation
to remove the light hydrocarbons and/or a secondary deasphalting. Any lighter
material
evolved in the vacuum distillation, or similar process, can be recovered and
recycled if required
in an upstream step, such as the deasphalting step for instance. Where the
cleaning step 62
involves a secondary deasphalting, the solvent used for this deasphalting step
can include a
saturated or unsaturated cyclic or heterocyclic hydrocarbon solvent. In some
implementations,
the secondary deasphalting solvent can be one or more of toluene, xylene,
benzene,
tetrahydrofuran, cyclohexanone, quinoline or pyridine, preferably
tetrahydrofuran. The
resulting chemically treated streams 68, or 67' if the optional step 62 is not
performed, can
then be further processed as previously described until obtaining the final
carbon fiber products
140, i.e., at least by extrusion, spinning, carbonization and surface
treatment.
[00242] More particularly, stream 67' or 68 is sent to extruding unit 70,
where pressure can
be applied to the chemically treated solid asphaltenes to remove any remaining
entrained
solvent. In some implementations, the chemically treated asphaltene
particulate stream 67' or
68 can be submitted to a crushing step before extrusion as previously
described. In some
implementations, the extruder is heated to a temperature in the 200-350 C
range to create
conditions to provide continuous flow as a Non-Newtonian fluid through and out
of the
equipment. The solvent removed in unit 70 can be returned to the SDA unit as
stream 73. In
another implementation, some of the generated asphaltene extrudate material in
stream 71
can be sent to for processing to become activated carbon. All or most of the
extruded material
39
Date Recue/Date Received 2022-09-13
can leave the extruding unit 70, as stream 75. In the next step, the extruded
material can be
treated in the spinning unit 80, where "green" carbon fiber can be produced as
stream 85. It is
to be noted that in some implementations, extrusion and spinning can be
performed in a single
unit. The spinning of the chemically treated asphaltenes material resulting in
the "green"
carbon fiber, can be accomplished by melt, jet or wet spinning. In some
implementations, melt
spinning is preferably used. After spinning, the green fiber made of a
continuous chemically
treated asphaltene thread can have a diameter that is less than 15 pm. In some
implementations, the diameter of the green fiber can be less than 10 pm. Then,
the continuous
asphaltene thread or "green" fiber 85 can be further processed as explain
above with respect
to Figures 1 or 2, to obtain the final carbon fiber product 140. Hence, the
continuous asphaltene
thread 85 can be heat stabilized/oxidized in unit 90 to form a stabilized
asphaltene stream 95,
which can itself be carbonized in unit 100, and then, the carbonized material
101 can be
surface treated in unit 110. In some implementations, the carbon fiber product
140, which is
obtained from the continuous asphaltene thread after carbonization and surface
treatment, can
have a tensile strength of at least 3.0 GPa and a Young's modulus of at least
400 GPa. In
some implementations, where the chemical treatment, which is carried out in
unit 65', includes
a treatment with an oxidizing agent, the stabilization/oxidization in unit 90
can be optional since
the asphaltene material has already been subjected to an oxidizing treatment.
In alternative
implementations, the carbonized material is sent as stream 103 to a
graphitization step 105
before surface treatment in unit 110. In some implementations, an activation
step 107 can also
be implemented, as explained above, between graphitization and surface
treatment. The
carbon fiber product 140 that is created after graphitization and surface
treatment can present
a tensile strength of at least 2.5 GPa and a Young's modulus of at least 500
GPa. The
implementation represented in Figure 3 can thus lead to a high-performance
carbon fiber
product 140, which can optionally be activated.
[00243] The implementations represented in Figures 1 to 3 can allow obtaining
carbon fibers
with different properties, which can be fine-tuned by implementing some steps
using specific
parameters (e.g., selecting a particular polymer to be added during extrusion
step 70, selecting
a specific chemical additive for step 65') and/or by implementing optional
steps enabling
obtention of a "cleaner" carbon fiber precursor material such as by heating,
sparging and/or a
secondary deasphalting step before the extrusion step of the process. A
variety of carbon fiber
products can thus be obtained from general purpose to mid- and high-
performance carbon
Date Recue/Date Received 2022-09-13
fibers. Such carbon fibers can be obtained directly from a heavy hydrocarbon
feedstock, such
as containing native asphaltenes, i.e., a feedstock which has not been
subjected to upstream
cracking for instance. However, in some implementations, as will be discussed
below in
reference to Figure 4, the heavy hydrocarbon feedstock can be subjected to
certain treatments
before the deasphalting treatment in unit 50.
[00244] Hence, in some implementations, as shown in Figure 4, the heavy
hydrocarbon
feedstock 5 can be thermally cracked in reactor 30 before the deasphalting
treatment in SDA
50. This step can allow recovering a portion of the heavy hydrocarbon
feedstock as a light top
fraction 33 while producing a heavy bottom fraction 32 containing
hydrocarbons, and thermally
modified asphaltenes. In reactor 30, the temperature can be controlled and
maintained while
the feedstock stream can undergo a mild controlled cracking process. A sweep
gas 31, can
be introduced into the reactor to assist in mixing the liquid pool in the
reactor and to assist in
removing any evolved vapors from the hydrocarbon feedstock. The sweep gas 31
can be any
type of non-condensable vapor that can end up in the fuel gas system for
combustion or reuse
in the process. Examples of sweep gas can be a hydrocarbon mixture such as
natural gas or
steam, nitrogen or hydrogen. In some implementations, after the mild cracking
process, the
light top fraction 33 can be routed from the reactor 30 to a gas liquid
condensing separator and
olefin saturation process 40. The heavy bottom fraction 32 containing
hydrocarbons and
thermally modified asphaltenes can be sent to the liquid/solid solvent
extraction process 50.
The condensed overhead liquid fraction 33 will have a much higher API gravity
than the bottom
fraction 32. For example, the overhead liquid fraction 33 can have an API
gravity of 26 or
greater. Although the characteristics of the bottom fraction 32 exiting the
reactor 30 can vary
depending on the process fluid input into the reactor 30 and the reactor's
operating parameters,
in some implementations, the bottom fraction 32 can have an API gravity
ranging between -5
and 5. In some implementations, the heavy hydrocarbon feedstock 5 can be
heated in heater
20 before being sent to the reactor 30 as stream 25. In some implementations,
the heater 20
can heat the feedstock 5 to a temperature between about 350 C and 420 C (e.g.,
about 675-
790 F) or between about about 370 C (700 F) to about 420 C (790 F). As
mentioned above,
an olefin saturation process 40 can receive the vapor stream 33 from the
reactor 30 to convert
the olefins in this stream to meet pipeline transport specifications. The
condensed olefin-
saturated liquid exits unit 40 as stream 45 and can be blended with the
solvent-diluted
deasphalted oil 57 produced in SDA 50 to form pipelinable stream 200. The non-
condensable
41
Date Recue/Date Received 2022-09-13
vapor exiting unit 40 as stream 43 can be sent to an H2S removal unit, such as
an amine unit,
and the vapor can be readily reused in the process or used as a fuel gas.
[00245] The solvent extraction process 50 can be similar to the one described
above with
reference to Figures 1 to 3. The recycled solvent stream 63 and/or 73 can be
mixed with the
heavy bottom fraction 32 to precipitate the solid asphaltenes therefrom and
recover the
separated diluted deaslphalted oil as stream 57. In some implementations,
additional makeup
solvent can be required to mix with stream 32 in separator 50. The asphaltenes
can be
precipitated in the form of solid powder/solid particulate and subjected to a
solid/liquid
separation in unit 50, as opposed to a typical liquid/liquid separation. A
solid/liquid separation
requires less solvent to provide the desired recovery of pipelineable heavy
oil. The solvent
used in SDA 50 can be a pure hydrocarbon component ideally in the range of C5
to C8, or more
practically, a mixture of C5 to C8 extracted from readily available natural
gas condensate or
diluent that comes in with the heavy crude feed.
[00246] The thermal cracker 30, can be operated at conditions that maximize
the economic
return for producing both the pipelineable crude 200 and the carbon fiber
product 140. In some
implementations, the process fluid 25 heated to about 350-420 C or about 370 C-
420 C
(about 700-790 F) by the heater 20 can undergo a mild controlled cracking
process in reactor
30. Appropriately located heaters are provided in reactor 30 to maintain the
desired constant
temperature generated in heater 20 and to apply uniform heat flux for the
fluid. The heaters
can provide indirect heat through any source readily available (electric, heat
transfer fluid,
radiant etc.). To ensure a uniform heat flux, mixing can be applied to the
process fluid on a
continuous or intermittent basis.
[00247] The reactor 30 can be operated while controlling several process
variables, including
the temperature, pressure, residence time, sweep gas and heat flux, so as to
reduce or even
prevent coke from forming during the reaction, and minimizing gas production,
while also
providing optimal conversion of the asphaltene portion of the heavy
hydrocarbon to provide
the desired mix of refinery-ready feedstock components.
[00248] In some implementations, a uniform heat flux between 7000-12000 BTU/hr
sq.ft (22.1-
37.8KW/m2) can be applied to the entire pool of process fluid in the reactor
30 and an operating
temperature between about 350-420 C (about 675-790 F) can be maintained in
the reactor.
42
Date Recue/Date Received 2022-09-13
This can be achieved by the presence of appropriately sized and located
heating devices in
the reactor. The number of heaters can be set by calculating the optimal
dispersion of heat
between any two heaters so as to have a uniform temperature throughout the
pool and to avoid
peak or spot temperatures significantly higher than the target temperature in
the reactor.
Avoiding peak temperature spots reduces the chance of generating coke in the
reactor. In
some implementations, the residence time in reactor 30 can be between 1 minute
up to 7
hours. As the residence time is increased, the expected concentration of
mesophase material
can increase. In further implementations, the operating pressure in reactor 30
can be
maintained at near atmospheric pressure and can be less than about 50 psig
(345 kPa). The
pressure range can be controlled on the low end to prevent excessive,
premature flashing of
hydrocarbon, essentially bypassing the reactor, and limited on the high end to
reduce
secondary cracking and consequent increased gas yields. In some
implementations, the
sweep gas 31 can be added to the process fluid in reactor 30 in the range of 0-
80 scf/bbl (0-
14.24 Sm3/Sm3) if deemed beneficial to improving the reactor performance. The
sweep gas 31
can be natural gas, hydrogen, produced/fuel gas from the process, steam,
nitrogen or any
other non-reactive, non-condensable gas that will not condense to a liquid.
Sweep gas in the
dosage of 0-80 scf/bbl (0-14.24 5m3/5m3) of feed can allow to remove the
"lighter" hydrocarbon
products (i.e., methane to <400 C (750 F) boiling point hydrocarbons) as soon
as they are
formed in the reactor 30 so that there is a minimum of secondary cracking,
which could
increase gas production and potentially increase olefinic naphtha/distillate
production. The
sweep gas can also allow the reactor to operate closer to the desired
operating pressure (<50
psig (345 kPa)) and temperature. The sweep gas 31 can also be used to provide
additional
heat and/or mixing to the process fluid in the reactor 30. Each thermal
cracking variable can
be changed independently, within the ranges suggested, based on the quality of
feedstock
provided or based on the quality and quantity of each output desired.
[00249] In some implementations, the overhead fraction 33 produced in reactor
30 can be
directed to a gas liquid separation unit 40, which can comprise a cooler and
separation drum,
as an example, in which a portion of the overhead fraction 33 that is a
condensable liquid
product containing naphtha and heavier hydrocarbons can be separated from the
gaseous
components of the overhead fraction 33. An off-gas line 43 containing
undesirable gases such
as sour gas, can be provided within the separation unit 40 for those gases to
be disposed of,
recycled, or subjected to further treatment.
43
Date Recue/Date Received 2022-09-13
[00250] In further implementations, still referring to Figure 4, a secondary
thermal cracking
unit 35 can be added to provide additional thermal cracking to the residue
portion of the crude
being produced as bottom fraction 32 in reactor 30. This optional step can
allow generation of
more mesophase material from the thermally affected asphaltene solid
powder/particulate and
the resulting stream 37 is fed to the SDA 50. As previously explained,
increasing the
mesophase content can contribute to the production of higher performance
carbon fiber.
[00251] Once the heavy hydrocarbon feedstock 5 has been treated in heater 20,
reactor 30,
optional unit 35, and SDA 50, the resulting asphaltene-containing stream 53
containing a slurry
or suspension of solid asphaltene particulate in the form of a vapor/solid
mixture, is sent to the
inertial separation unit (ISU) 60 for a solid/vapor separation. Solvent vapor
is condensed and
returned to the SDA unit 50 for reuse as stream 63. The slurry containing the
solid asphaltene
particulate is sent to the next step, which can be extruder unit 70 or to an
optional pre-
conditioning step 65, before extrusion takes place. Hence, in some
implementations, the solid
asphaltene particulate stream 61 can be directly sent to the next process
step, which includes
extrusion of the solid asphaltene particulate material in unit 70. In an
optional implementation,
the solid asphaltene particulate stream 61 exiting the ISU 60 can be further
treated in unit 65
before the next extrusion step. Hence, in some implementations, the process
can involve
sending the solid asphaltene particulate stream 61 to unit 65 where a further
treatment is
performed to separate any undesirable solids (also referred to as
"insolubles") that hinder the
generation of carbon fiber, from the solid asphaltene particulate stream 61.
The undesirable
solids can be removed as stream 64 and a cleaner asphaltene particulate-
containing stream
67 can be produced. The undesirable solids that are removed in unit 65 can
contain various
solid particles, inorganic material, and/or dirt that was present in the
feedstock. In some
implementations, unit 65 can contain a second solvent deasphalting step using
organic
solvents that adsorb heavier molecules than the solvent that is used in the
SDA 50. The
solvents that can be used to reject the heaviest, most undesirable solids in
the solid asphaltene
particulate stream 61 can include saturated or unsaturated cyclic or
heterocyclic hydrocarbon
based compounds, such as toluene, xylene, benzene, tetrahydrofuran,
cyclohexanone,
quinoline and pyridine among others. In some implementations, vacuum
distillation can also
be used in unit 65, alone or in combination with the second deasphalting step,
to remove any
remaining lighter molecules that could create voids in the carbon fiber. Any
lighter material
evolved in the vacuum distillation or similar process, including the saturated
or unsaturated
44
Date Recue/Date Received 2022-09-13
cyclic or heterocyclic hydrocarbon based solvent, will end up as stream 66. In
addition,
sparging can be considered within unit 65 to produce more mesophase material
by removing
lighter components and altering the orientation of the carbon molecules to
promote high-
performance carbon fiber in stream 140. Sparging is a process similar to air
blowing, and for
carbon fiber, sparging is generally conducted with inert nitrogen instead of
air.
[00252] The solid asphaltene particulate stream 61 or 67 can then enter the
extruder unit 70
where pressure can be applied to the solid asphaltenes to remove any remaining
entrained
solvent. In some implementations, the solid asphaltene particulate stream 61
or 67 can be
submitted to a crushing step before extrusion as explained above. In some
implementations,
the extruder is heated to a temperature in the 200-350 C range to create
conditions to provide
continuous flow as a Non-Newtonian fluid through and out of the equipment. The
solvent
removed in unit 70 can be returned to the SDA unit as stream 73. Some of the
generated
asphaltene extrudate can be segregated and sent to the solid fuels market, as
stream 71, if
the market for carbon fiber is saturated or not economic. In another
implementation, material
in stream 71 can be sent to for processing to become activated carbon. The
majority of the
extruded asphaltenes leave the extruding unit 70 as stream 75. The next steps,
which
sequentially can include melt, wet or jet spinning in unit 80, heat
stabilization in unit 90,
carbonization in unit 100, graphitization in unit 105, activation in unit 107
and surface treatment
in unit 110, to finally produce the final carbon fiber product 140, can be
performed in the
conditions as described above with respect to the implementations shown in
Figures 1 to 3.
More particularly, in some implementations, stabilization in unit 90 can be
performed at a
stabilizing heat treatment from about 175 C to about 290 C (about 350 F to
about 550 F) for
up to 1 hour. In some implementations, carbonization in unit 100 can be
performed at a
carbonizing heat treatment from about 995 C to about 2000 C (about 1823 F to
about 3632 F)
for up to 1 hour. The graphitization step in unit 105 can be carried out by
heating the carbonized
carbon fiber obtained in the carbonization step to a temperature over 3000 C
(5432 F). In
some implementations, the graphitized carbon fiber resulting from the
graphitization in unit 105
can be activated by contacting the graphitized carbon fiber with steam, for
instance using
steam at a temperature of about 800 C to about 900 C and a steam rate of
about 100 g/hr to
about 200 g/hr. In some implementations, the activated carbon fiber obtained
in unit 107 can
present a BET surface area of at least 500 m2/g. In some implementations, the
activated
carbon fiber can have a BET surface area of at least 1000 m2/g.
Date Recue/Date Received 2022-09-13
[00253] The carbon fiber product 140, which can be produced from an
implementation such
as the one discussed with reference to Figure 4 is thus an activated carbon
fiber, which can
present various performance depending on whether the optional steps in unit 35
and 65 are
implemented. In some implementations, the activated carbon fiber product 140
can have a
tensile strength of at least 1 GPa and a Young's modulus of at least 100 GPa.
It is to be noted
that for this implementation generally aiming to obtain an activated carbon
fiber, the tensile
strength and Young's modulus are not as critical. As previously mentioned,
activation of the
carbon fiber is mainly performed to obtain carbon fibers suitable for
filtration applications (e.g.,
to increase water or air purity) and in a form allowing them to be molded to
desired shapes for
such filtration applications.
[00254] As previously mentioned, the processes and systems described herein
advantageously allow the production of carbon fiber products, which can be
activated, and
present performances, which can be fine-tuned depending on the intended
application for the
final carbon fibers.
EXPERIMENTATION
[00255] Athabasca bitumen with an API of 8.2 was used in the examples. For
examples 1, 2
and 3 relating to Figures 1, 2 and 3, the bitumen was subjected to an initial
solvent deasphalting
and inertial separation (steps 50 and 60) to create a stream of native
asphaltenes in powder
form containing 95 wt% C5+ asphaltenes. The recovery after the solvent
deasphalting was
98.4 wt% recovery of the C5+ asphaltenes. The stream of native asphaltenes
that was then
used in the various processes for obtaining carbon fiber.
[00256] Example 1 ¨ Native asphaltenes of size below 80 pm were extruded/melt
spun as is
in an extruder/melt-spinning combination apparatus at 300-310 C, 300 psi melt
spin pressure,
at 120-140 m/min spinning speed, then stabilized at 400 C and carbonized at
1200 C to
generate general purpose quality carbon fiber.
[00257] Example 2 ¨ Native asphaltenes were combined with 30-35 wt%
polypropylene for
extrusion (step 70) and then wet spun at 100-120 C, at 100-120 m/min spinning
speed, then
stabilized at 380 C and carbonized at 1200 C to generate medium performance
carbon fibre.
46
Date Recue/Date Received 2022-09-13
[00258] Example 3 ¨ Native asphaltenes were mixed with 15 wt% oxidizing
chemical agent
(H202) for chemical treatment (step 65') and then melt spun at 290-300 C, at
120-130 m/min
spinning speed, then stabilized at 400 C and carbonized at 1200 C to generate
high-
performance carbon fibre.
[00259] For Example 4, the Athabasca bitumen was first thermally cracked at
near
atmospheric conditions (3 psig) (step 30 of Figure 4) and the thermally
affected C5+
asphaltenes were separated by solvent deasphalting and inertial separation
(steps 50 and 60)
to generate a stream that contains 95 wt% C5+ asphaltenes with 98.4 wt%
recovery of the
C5+ asphaltenes. The thermally affected C5+ asphaltenes were further
conditioned with
tetrahydrafuran (step 65). The soluble portion was melt spun at 310-315 C, 305
psi melt spin
pressure, at 100-110 m/min spinning speed, then stabilized at 400 C and
carbonized at
1200 C to generate general purpose quality carbon fibre.
[00260] Some properties of the carbon fiber resulting from Examples 1 to 4 are
provided in
table 1 below.
[00261] Graphitization and activation can further be applied to all 4 examples
shown in the
table to improve the tensile strength and modulus along with improved surface
area.
[00262] In Example 5, the asphaltene sample created through the process steps
from
Example 4 was submitted to a graphitization step, where heat was applied at
2200 C for 10-
20 minutes.
[00263] In Example 6, the asphaltene sample created through the process steps
from
Example 4 was submitted to steam activation. Steam at 150 g/hr and 900 C was
applied for 1
hour to the sample to activate the carbon fiber to improve the surface area of
the structure for
improved filtration applications.
[00264] Some properties of the carbon fiber resulting from Examples 5 and 6
are provided in
table 2 below. The data for the carbon fiber of Example 4 are also reported in
Table 2.
47
Date Recue/Date Received 2022-09-13
[00265] Table 1
Examples Diameter Softening Tensile Tensile
Green fibre Point Strength (Young's)
(pm) ( C) (MPa) Modulus
(GPa)
Example 1 ¨ native 15-20 215-220 1500 200
asphaltene
Example 2¨ 10-15 207-212 3500 250
polypropylene
addition
Example 3¨ 10-15 215-225 3000 400
chemical agent
addition ¨ H202
Example 4 ¨ 15-20 227-230 1000 100
Thermal crack 1st
[00266] Table 2
Examples Diameter Tensile Tensile BET Surface
Green fibre Strength (Young's) Area
(pm) (MPa) Modulus (m2ig)
(GPa)
Example 4¨ 15-20 1000 100 96
Thermal crack 1st
Example 5- 15-20 950 275 -
Graphitized
Example 4 sample
Example 6¨ 15-20 980 95 1040
Activated Example
4 sample
48
Date Recue/Date Received 2022-09-13
