Note: Descriptions are shown in the official language in which they were submitted.
COMPOUND IN-SITU AND MINABLE OILSANDS WASTE DISPOSAL
FIELD OF THE INVENTION
The present invention is generally related to the field of disposal of in-situ
liquid waste, like evaporator
and crystallizer blow-down, and the disposal of open mine oilsand extraction
plant tailing waste.
BACKGROUND
There are two types of oilsands in Alberta ¨ minable and non-minable. The non-
minable oilsands are
located at greater depths that are not practical to mine. The extraction of
the two types of oilsands
formations is significantly different ¨the minable formation is mined and
trucked to an extraction plant.
The sand and other solids, together with some oil remains, are disposed of in
a tailings pond. In the
process, stable non-segregate tailings are generated and accumulate in the
tailings pond. To extract the
non-minable oilsands formation steam, sometime with solvents, is injected into
the underground
formation. The most commonly used methods are Steam Assisted Gravity Drainage
(SAGD) and the
Cyclic Steam Stimulation (CSS). Both use wells directed into the underground
oilsands formation. The
steam requires water which is first treated to remove contaminates, mainly
dissolved solids and
organics. There are a few methods currently used to treat the water. The
methods include softening,
membrane, and evaporation. In the last few years, the evaporation process to
treat the water has
gained popularity due to the possibility of using brackish water with high
levels of dissolved solids. The
water source for the minable and non-minable extraction plants are
significantly different ¨ most of the
minable extraction plants use river water from the Athabasca River as their
water source, while most
SAGD and CSS non-minable extraction facilities use water wells as their water
source. The two processes
eventually generate very different liquid disposals streams - the in-situ
(like SAGD and CSS) extraction
facilities generate a disposal stream with high levels of dissolved solids,
mainly salts, while the minable
extraction facilities generate a disposal stream with high levels of suspended
solids, mainly clay.
In recent years, there was a push toward Zero Liquid Discharge (ZLD) systems
in in-situ oilsands
production plants. One problem with the dissolved solids generated by in-situ
ZLD system is they are
considered to be more challenging for disposal. This is due to the fact that
the solids, mainly salts, easily
absorb water, and due to their hygroscopic behavior, whereby they dissolve
back to a liquid waste.
When this occurs, the land fill becomes challenging, especially in wet seasons
(periods of rainfall) where
leaching become a significant concern.
ZLD systems were first used commercially by the in-situ industry. One example
is PetroCanada Mackay
River SAGD where a ZLD system was used. In this plant, an evaporator was used
to treat the water while
the disposal flow was directed to a crystallizer and possibly a filter press
and a dryer. It was found that,
although ZLD waste is achievable, the waste containing high level of salts,
has a tendency to absorb
water, like rain, and complicate its disposal in a landfill. (See Petrocanada
presentation "Zero Liquid
Discharge at MacKay River. Presented by Gary Giesbrecht at the CHOA on
February 13, 2007.)
The present invention combines the two waste streams, treats them with
intensive heat to dry the
water from the clay, and combines the two streams to generate a more stable
disposal waste.
US patent 3,837,872 issued on September 24, 1974 to Conner describes a
solidification method for
liquid waste by mixing an aqueous solution of an alkali metal silicate with
the waste fluid and a silicate
setting agent to cause the silicate and setting agent, from the group
consisting of Portland cement, lime,
gypsum and calcium chloride, to react with each other. The reaction converts
the mixture into a
consolidated, chemically and physically stable solid product that is
substantially insoluble in water and in
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Date Regue/Date Received 2023-06-19
which pollutants are entrapped in the solidified silicate so that the waste
material is rendered
nonpolluting for disposal.
US patent 3,980,558 issued on September 14, 1976 to Thompson describes a
process for permanently
disposing of liquid or semi-liquid wastes containing soluble toxic materials
which comprises admixing
the liquid or semi-liquid waste, such as aqueous sludge from the manufacture
of phosphoric acid
containing soluble and insoluble arsenic, sulfur and like toxic compounds,
with a solidifying agent
consisting essentially of a hydraulic cement in amounts sufficient to provide
a fluid mass that will set to
a contiguous rock-like solid upon standing, and then allowing the admixture to
set to a contiguous rock-
like solid mass which is insoluble in water. The soluble and insoluble toxic
materials of the waste are
wholly entrapped in the contiguous rock-like solid mass which thereby prevents
them from being
leached into the surrounding environment when exposed to ambient moisture. The
liquid or semi-liquid
waste and hydraulic cement are admixed in an amount of at least about 9 lbs.
hydraulic cement per
gallon of said waste, based upon the waste containing about 30 to 40 volume %
solids; and allowing the
admixture to set to a contiguous rocklike solid, insoluble in water, whereby
said toxic materials are
entrapped and prevented from leaching into the surrounding environment.
US patent 4,149,968 issued on April 17, 1979 to Kupiec describes a process for
converting a liquid-
containing, polluting waste, having metallic ions, into an inert, nonpolluting
material, which comprises
adding and mixing a neutralizing agent to adjust the pH value of said waste to
between a value greater
than 6 and up to about 11, adding and mixing with said waste bentonite clay
having a weight up to 30%
of the weight of the waste, and thereafter adding and mixing, with said
mixture, Portland cement having
a weight up to 50% of the weight of the waste; the reaction time being from
about 1/2 to about 5 hours
to form a solid mass. The quantities of bentonite and cement control the
consolidation of materials and
govern physical factors such as the hardness and the chemical characteristics
of the resultant material.
This resulting product is chemically and physically stable; a solidified
product which is almost completely
insoluble in water, and in which, pollutants are encapsulated in the matrix so
that the waste material is
rendered non-polluting and fit for ultimate disposal.
US patent 4,209,335 issued on June 24, 1980 to Katayama et al. describes the
solidification and fixation
of waste containing toxic contaminants by use of a composition made up of
hydraulic cement and an
additive containing aluminum sulfate, alum, ferrous sulfate and ferric
sulfate, and an alkaline metal salt
selected from the group consisting of alkaline metal carbonate, bicarbonate
and silicate.
US patent 4,880,468 issued on November 14, 1989 to Bowlin et al. describes a
waste solidification
composition comprising hydraulic Portland cement, fly ash and fumed silica
material which is used to
solidify agglomerations of solid and liquid waste materials, such as drilling
muds and cuttings that result
from the drilling of an oil and gas well.
US patent 5,370,185 issued on December 6, 1994 to Cowan et al. describes
combining an aqueous
drilling fluid, containing clay such as prehydrated bentonite, with a slurry
of Portland cement in oil. The
resulting composition is used primarily for cementing operations for oil
wells.
US patent 5,673,753 issued on October 7, 1997 to Hale et al. describes the in-
situ process of converting
drilling mud to a cement by the addition of blast furnace slag. The in-situ
solidification of water-based
drilling muds leads to compressive strengths well in excess of that required
for casing support, zonal
isolation and borehole stability. The method includes injecting drilling fluid
into the borehole, adding
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Date Regue/Date Received 2023-06-19
blast furnace slag to the drilling fluid, displacing the drilling fluid to a
preselected location in the
borehole, and allowing the drilling fluid to solidify in-situ.
US patent US 8,127,843 issued on March6, 2012 to Solomon et al. describes the
solidification of water
treatment wastewater brines from oil production operations. Concentrated
wastewater brines from
water treatment systems in heavy oil recovery operations are converted to
solids suitable for landfill
using Portland cement. The method includes injecting steam into a geologic
formation, recovering an
oil-water mixture, separating the oil and the water from the oil-water
mixture, concentrating the
separated water to produce a concentrated wastewater brine, adding a
cementious alkali formulation to
the concentrated wastewater brine to produce a wet cement-brine mixture, and
allowing the wet
cement-brine mixture to solidify.
The proposed solidification process eliminates expensive drying equipment for
wastewater brine solids,
as well as the associated operation and maintenance of expensive dewatering
equipment.
US Patent Application Publication US 2012/0090509A1 published on March.6, 2012
by Albert describes
utilizing drilling byproducts from gas and oil wells to make commercially-
marketable concrete. The drill
cuttings and flow-back byproducts are treated with a calcium oxide dewatering
agent to form a waste
slurry, and the waste slurry is then added to a concrete mixing process which
consists essentially of
cement, a coarse aggregate, and water as the final component, after all of the
other components of the
concrete-mixing process have already been blended together.
SUMMARY OF THE INVENTION
The current invention is a method and system for treating and for the solid
disposal of in-situ liquid
waste and a minable tailing stream.
The most common disposal method of in-situ water treatment liquid waste is
injecting it into a disposal
well. The in-situ disposal stream typically contains high levels of dissolved
solids from the boilers blow
down (package boilers of Once Through Steam Generators, OTSG) if an
evaporating water treatment
facility is used, the concentrated brine can also be disposed of into a
disposal well. Disposal wells are the
preferred disposal method by the operators but due to the higher minimum cost
for treating the waste
stream, they are not always feasible. In addition, when large amounts of
disposal liquids are injected
underground, it might eventually immigrate and have a negative impact on the
environment. In some
locations, salt caverns are generated to address the precipitation of the
disposal liquid. The salty water
used to generate the salt cavern, together with the disposal water from the
evaporator, are injected into
a disposal well. The environment regulators in Canada are aware of this
problem and in some locations,
disposal wells are not approved for use. A solid disposal of the waste solids
within the waste stream is
preferred as solid disposals are more stable and do not migrate to other
locations. There are a few
methods to generate solid waste from an in-situ liquid stream. Some facilities
use a solid disposal of the
waste stream. The method commercially used includes crystallizer, a filter to
recover the dissolved solid
crystals, and a dryer to dry the solid waste to prepare it for disposal. There
were a few problems with
this particular solid waste. It is hygroscopic and if it comes in contact with
water, it will easily dissolve to
create liquid waste that can migrate. Rain or other precipitations can
generate this problem and the
solid waste, mainly salts, should be protected from precipitation. Another
problem is the use of dryers
at the in-situ location. Because in-situ recovery is a steam-based process the
dryer heat cannot be
effectively recovered and it is lost to the environment.
A different extraction process that is used to recover bitumen from oilsands
is the open mine extraction
facility. This type of extraction is used where the deposits of the oilsands
are close to the surface so they
can be mined. The extraction process generates a different type of liquid
waste stream that is called
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Date Regue/Date Received 2023-06-19
tailings. The tailings include water, clay solvents and other contaminates
such as asphaltene, dissolved
solids, heavy metals hydrocarbons, etc. One major difference between the two
types of waste streams
generated in the in-situ extraction and the open mine extraction is that in
the in-situ liquid waste stream
most of the solids are dissolved (salts) while in the open mine extraction
most of the solids are fine
suspended solids (mainly fine clay) that was trapped in the sand and bitumen
and released by the
extraction process.
The current invention integrates these different waste materials and treats
them in a way to combine
them into a solid material that will be more stable than the in-situ dissolved
material to achieve a better,
more environmentally sound disposal method. Another advantage is the
elimination of the need to fully
dry the dissolved solids waste generated in the in-situ water treatment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention integrates the two different waste streams generated by
in-situ and minable
oilsands extraction facilities to generate a stable solid that can be
effectively disposed of in a landfill. The
mined oilsands extraction facility includes water-based extraction, possibly
with the aid of solvents. The
present processes include mixing oilsands ore with warm water, possibly with
chemicals like NaOH,
solvents, etc. Separation of the hydrocarbons and some water occurs in a
primary separation vessel to
generate a flow of course tailings (mainly a flow of sand and rocks). The
coarse tailings flow is directed
to the tailings pond where the coarse tailings are easily separated into
recyclable water and sand that is
used in the tailings pond construction. The recovered hydrocarbons and froth
flow are treated in
floatation cells, possibly with the help of solvents. The froth treatment
typically includes solvents that
recover additional hydrocarbons and that can remove asphaltin from the bitumen
to produce a high-
quality product. The fine tailings from the floatation cells and from the
froth treatment facility can be
further treated to recover heat and additional water in a thickening facility
where thickened tailings are
generated. The major advantage of the thickening process is its ability to
recover additional process
water while maintaining the heat energy within the feed fine tailings. The
waste streams that include
solids (mainly fine clay particles possibly with asphaltene) with liquid,
(mainly solvents and water) are
heated in a dryer to generate a dry solid stream after the liquids have been
removed. Depending on the
temperature, the clay content can be calculated and crystal water removed. In
this process kaoline is
transferred into metakaolin. This can be done in a single process facility or
in two steps where in the first
step the liquid is evaporated to generate a solid waste while in the second
step the dry solids are heated
to remove crystal water, and generate calcinated solids and metakaoline which
are "water starving"
solids capable of chemically reacting with liquid water.
The in-situ oilsands extraction facility includes injecting steam, possibly
with solvents, into an
underground formation through an injection well and recovering the bitumen and
the water through a
production well. Due to the nature of the process, a large amount of water is
required for steam
generation. The steam mobilizes the bitumen and separates it from the sands.
The bitumen and water
mix is recovered back to the surface. The process water includes recycled
water and make-up water. The
process water includes significant amounts of dissolved solids as well as
hydrocarbons and solvent
remains. To generate steam, the water is treated to remove hardness and other
contamination. The
water quality produced by the water treatment process is dictated by the steam
generation facility.
Where an OTSG is used for generating the steam, the water can include
relatively high levels of
dissolved solids (typically up to 8,000 TDS). Oil removal and ion exchange
processes are used to treat the
water to a Direct Contact Steam Generator (DCSG) quality. The blow-down from
the boiler, which
contains a high concentration of dissolved solids, is disposed of in disposal
wells. Another steam
generation method is to use a package boiler with mud drum and/or steam drum.
The water
requirement for this method of steam generation is higher than of the OTSG and
de-mineralization is
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Date Regue/Date Received 2023-06-19
required. Typically, the water is treated with an evaporator after de-oiling
to remove the oil
contamination. The water is evaporated to generate a distilled water stream
and a brine stream. The
brine stream includes the dissolved solids that were in the feed water. The
brine concentration can
reach up to 200,000 TDS. The brine can be further treated in a crystallizer,
possibly with a filter press to
generate wet solids. The wet solids from the crystallizer are not suitable for
disposal as they contain too
much water. The solids from the crystallizer are further dried with a dryer to
evaporate the liquid water
remains into the atmosphere while generating dry solids. One problem with
disposing of the dried solids
is the hygroscopic nature of the dissolved solids, mainly salts. These solids
are easily dissolved again
when they come in with contact water which complicates the landfill disposal.
When the solids dissolve,
they can flow and contaminate the environment. The method and system described
herein is designed
to prevent this problem by combining the two very different waste flows from
the open mine
(suspended solids like fine clay) and the in-situ oil extraction facilities
(dissolved solids, mainly salts). The
combined flow will be more stable than the solids from the in-situ process. It
will also minimize the dust
problem of the open mine dried tailings. In one embodiment, it will reduce the
need to further dry the
dissolved solids in the in-situ extraction process as the mixture with the dry
"water starving" solids of
the open mine tailings will hold the excess water within the in-situ dissolved
solids waste stream while
generating a stable solid. A ZLD system is a cost-effective option if there
are no disposal wells. The cost
of 3rd party disposal is estimated to be in the range of $100-$150 /m3 and the
water balance improves as
close to 100% of the water is recycled back to the process. Some problems with
the evaporation and
crystallizer are the water-soluble organics that are dissolved by the water
from the bitumen and the
solvents used are non-volatile. These accumulate in the crystallizer and
increase the viscosity of the
crystallizer while generating a denser and more abrasive slurry. By purging
the crystallizer, concentrated
liquids with water soluble organics are removed from the crystallizer to
prevent accumulation. The
concentrated liquids are mixed with the dry fine tailings solids to generate a
stable, solid material for
effective disposal in a landfill without free liquids and without leaching.
FIGURE 1 describes a schematic flow diagram of the proposed invention process.
The process includes
the following steps:
Injecting steam into an underground formation.
Recovering bitumen and produce water from the underground formation.
Treating the produced water in an evaporator to generate distilled water for
steam generation and a
waste stream with high levels of dissolved solids for disposal.
Extracting bitumen from the minable oilsands facility with liquid water and
solvents while generating a
stream of non-segregate fine tailings with suspended solids, mostly clays.
Heating the liquid tailings to generate dry solids and to recover the water
and solvents.
Mixing the liquid waste stream, with high levels of dissolved solids, and the
dry solids, mainly clays, to
generate a stable solid material.
Disposing of the solid material.
FIGURE 2 describes a schematic flow diagram of the proposed invention process.
The process includes
the following steps:
Producing bitumen and produce water from an underground formation.
Treating the produced water in an evaporator to generate distilled water for
steam generation and a
waste stream with high levels of dissolved solids for disposal.
Extracting bitumen from minable oilsands facility with liquid water and
solvents while generating a
stream of non-segregate fine tailings with suspended solids, mostly clays.
Heating the liquid tailings to generate dry solids and to recover the water
and solvents.
Date Regue/Date Received 2023-06-19
Mixing the liquid waste stream, with high levels of dissolved solids, and the
dry solids, mainly clays, to
generate a stable solid material.
Disposing of the solid material.
FIGURE 3 describes a schematic flow diagram of the proposed invention process.
The process includes
the following steps:
Extracting bitumen and produced water from an underground formation through a
well in an in-situ
extraction facility.
Separating the produced bitumen and produced water.
De-oiling the produced water to remove excess oil.
Treating the produced water to generate boiler feed water and a waste liquid
stream.
Extracting bitumen from minable oilsands ore while generating non-segregated
tailings.
Mixing the in-situ waste liquid stream and the minable non-segregated
tailings.
Heating the mixture to evaporate the liquids and to generate dry solids.
Disposing of the solid material.
FIGURE 4 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Extracting bitumen and produced water from an underground formation through a
well in an in-situ
extraction facility.
Separating the produced bitumen and produced water.
De-oiling the produced water to remove excess oil.
Evaporating the produced water to generate boiler feed water and a waste
liquid stream, where the
evaporation system can include a Mechanical Vapor Compression (MVC)
evaporator, Multiple Effect
Distillation (MED) evaporator or Multi-Stage Flash (MSF) evaporator, possibly
with a crystallizer to treat
the evaporator brine and increase the brine solids concentration.
Extracting bitumen from minable oilsands ore while generating non-segregated
tailings.
Mixing the in-situ waste liquid stream and the minable non-segregated
tailings.
Heating the mixture to evaporate the liquids and to generate dry solids.
Disposing of the solid material.
FIGURE 5 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Injecting steam, possibly with solvents, for in-situ bitumen extraction.
Producing bitumen and water from an underground formation through a well in an
in-situ extraction
facility.
Separating the produced bitumen and produced water.
Evaporating the produced water to generate boiler feed water and in-situ
brine.
Generating steam with the boiler feed water.
Extracting bitumen from minable oilsands ore while generating a non-segregated
solids, water and
solvent stream (non-segregated tailings).
Heating the non-segregated solids and liquids stream to evaporate the liquids
and to generate dry
solids.
Mixing the in-situ waste liquid brine stream and the dry solids.
Disposing of the solid material.
FIGURE 6 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
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Date Regue/Date Received 2023-06-19
Injecting steam, possibly with solvents, for in-situ bitumen extraction.
Producing bitumen and water from an underground formation through a well in an
in-situ extraction
facility.
Separating the produced bitumen and produced water.
Evaporating the produced water to generate boiler feed water and in-situ
brine.
Generating steam with the boiler feed water.
Extracting bitumen from minable oilsands ore while generating a solids, water
and solvent stream (also
referred to as fine tailings).
Mechanically recovering a portion of the liquids, mainly water and solvents,
from the non-segregated
solids, water and solvent stream to generate a slurry.
Heating the non-segregated solids and liquids stream to evaporate the liquids
and to generate dry
solids.
Mixing the in-situ waste liquid brine stream and the dry solids.
Disposing of the solid material.
FIGURE 7 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Injecting steam, possibly with solvents, for in-situ bitumen extraction.
Producing bitumen and water from an underground formation through a well in an
in-situ extraction
facility.
Separating the produced bitumen and produced water.
Treating the produced water by evaporation, membrane filtration, softening, or
some combination
thereof, to generate boiler feed water and an in-situ liquid waste stream.
Generating steam with the boiler feed water.
Extracting bitumen from minable oilsands ore while generating a solids, water
and solvent stream.
Recovering a portion of the liquids from the solids, water and solvent stream.
Heating the non-segregated solids and liquids stream to evaporate the liquids
and to generate dry solids
that include clay.
Heating the dry solids that include clay to create dry solids, by completing
at least a portion of:
calcinating, generating metakaolin, releasing crystal water, evaporating the
liquids and generating dry
solids.
Mixing the in-situ waste liquid brine stream and the dry solids.
Disposing of the solid material.
FIGURE 8 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Extracting bitumen and produced water from an underground formation through a
well in an in-situ
extraction facility.
Separating the produced bitumen and produced water.
De-oiling the produced water to remove excess oil.
Treating the produced water to generate boiler feed water and a waste liquid
stream where the water
treatment process includes an evaporation process, a lime softening process,
or both.
Spreading the in-situ waste liquid or slurry stream in a thin layer in a
designated area.
Extracting bitumen from minable oilsands ore while generating fine tailings.
Heating the fine tailings to evaporate the liquids and thereby generating dry
solids.
Spreading the minable dry solids waste on top the in-situ liquid or slurry
layer to remove any excess
liquid and to stabilize the disposal area.
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Date Regue/Date Received 2023-06-19
FIGURE 9 further describes the present invention. Produced emulsion 2 that
includes water with
dissolved and suspended solids, bitumen, and possibly solvents, is recovered
from production well 1.
The emulsion is separated in separation vessels 3 into gas, bitumen, possibly
solvents 4, and produced
water 5. The produced water 5 is de-oiled 6 and organics are removed 7. The de-
oiled stream 8 is
treated in an evaporation facility to remove contaminations, mainly dissolved
solids. Another option
(not shown) is to treat a portion of the water in an ion exchange process (hot
/ warm lime softener)
while treating only a portion of the flow in an evaporation facility to remove
dissolved solids, mainly
salts. The de-oiled stream 8, possibly with blow down water from the steam
generation facility 17, is fed
20 into evaporator 23. The evaporator shown is an MVC type evaporator where
water vapor 25 from the
brine sump 29 is compressed by a mechanical vapor compressor 21 into a falling
film heat exchanger 26
where condensation occurs to generate distilled water 30 which is high quality
Boiler Feed Water (BFW).
Brine from the sump 27 is recycled by pump 28 and fed to the falling film heat
exchanger where it cools
the vapor while evaporating it. To maintain the brine 29 concentration, to
prevent exceeding the
maximum recommended concentration in the evaporator as recommended by the
evaporator supplier
for the feed water composition and the process used in the evaporator
(typically not to exceed 150,000
TDS), brine 31 is removed to a crystallizer where additional water is
evaporated and recovered from the
brine 31 using steam heat energy. Low pressure steam 18 generated at the steam
generation facility 12
heats the brine water 35 at the crystallizer. Brine 37 is circulated through
pump 36 and heated 35 in
heat exchanger 33 with the Low Pressure (LP) steam 18. Vapor 40 is generated
in the crystallizer 40 from
the heated brine 34. The condensate from heating the LP steam 32 is recovered
and used as BFW. The
generated water vapor 40 is condensed in condenser 41 where heat, Q, is
recovered and used in other
parts of the process. The water crystallizer condensate 42 is used as BFW for
the steam generation 19.
High Pressure (HP) steam 15 is generated in steam generation facility 12 and
injected into a steam
injection well 16 for bitumen recovery. The steam generation facility can
include any commercially
available steam generation technology such as an Industrial / Package boiler,
forced circulation boilers,
or OTSG. Highly concentrated brine with high levels of dissolved solids and
solids phase crystals 38 are
removed from the crystallizer 39. The liquid phase concentrated brine 38 is
mixed with dry fine particles
51 that include dry clay particles that are generated by drying the fine
tailings stream generated in an
open mine oilsands extraction plant. In one option, the fine tailings drying
process includes exposure to
high temperatures, like in a kiln type combustion dryer. The dry powder 51
will include calcinated or de-
hydrated "water starving" materials that react with water to generate crystals
like metakaolin. These
types of materials are highly effective in converting the concentrated brine
into a stable solid material
that can be safely disposed of in a landfill with minimum risk of leaching to
the surrounding
environment. The concentrated liquids from the crystallizer 38, rich in
dissolved solids, are mixed 43 in
any commercially available mixer with the dry fine particle solids 51
generated by the dryer of the non-
segregated fine particulate solids in the mine extracted oilsands plant. The
actual mixing can be at the
dryer itself. For that option, the high TDS liquids are added to the last
portion of the dryer and mixed
with the fine particles inside the dryer itself. Another option is to mix the
open mine dry solids and the
crystallizer liquid in a rotating mixer which also agglomerates the solids to
particles that can be easily
disposed of in a landfill.
FIGURE 10 further describes the present invention. A typical Oilsands
extraction mine facility is briefly
described (See "Past, Present and Future Tailings, Tailing Experience at
Albian Sands Energy"
presentation by Jonathan Matthews from Shell Canada Energy on December 8, 2008
at the International
Oil Sands Tailings Conference in Edmonton, Alberta). Mined oilsand feed is
transferred in trucks to an
ore preparation facility, where it is crushed in a semi-mobile crusher 3. It
is also mixed with hot water 57
in a rotary breaker 5. Oversized particles are rejected and removed to a
landfill. The ore mix goes
through slurry conditioning, where it is pumped through a special pipeline 7.
Chemicals and air are
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Date Regue/Date Received 2023-06-19
added to the ore slurry 8. The conditioned, aerated slurry flow is fed into
the bitumen extraction facility,
where it is injected into a Primary Separation Cell 9. To improve the
separation, the slurry is recycled
through floatation cells 10. Oversized particles are removed through a screen
12 in the bottom of the
separation cell. From the flotation cells, the coarse and fine tailings are
separated in separator 13. The
fine tailings flow to thickener 18. To improve the separation in the
thickener, flocculant is added 17.
Recycled water 16 is recovered from the thickener and fine tailings are
removed from the bottom of
thickener 18. The froth is removed from the Primary Separation Cell 9 to
vessel 21. In this vessel, steam
14 is injected to remove air and gas from the froth. The recovered froth is
maintained in a Froth Storage
Tank 23. The steam can be produced in a standard high pressure steam boiler
40, in an OTSG, or by a
COGEN using the temperature in a gas turbine tail (not shown). The boiler
consumes fuel gas 38 and air
39. The coarse tailings 15 and the fine tailings 19 are removed and sent to a
tailings processing area or
to a tailings pond.
The tailings ponds are built in such a way that the sand tailings are used to
build the containment areas
for the fine tailings. The tailings come from the Extraction Process. They
include: the cyclone underflow
tailings 13, mainly coarse tailings, and the fine tailings from the thickener
18, where flocculants are
added to enhance the solids settling and recycling of warm water. Another
source of fine tailings is the
Froth Treatment Tailings, where the tailings are discarded by the solvent
recovery process -
characterized by high fines content, relatively high asphaltene content, and
residual solvent. (See "Past,
Present and Future Tailings, Tailing Experience at Albian Sands Energy" a
presentation by Jonathan
Matthews from Shell Canada Energy on December 8, 2008 at the International Oil
Sands Tailings
Conference in Edmonton, Alberta). A sand dyke 55 contains a tailing pond. The
sand separates from the
tailings and generates a sand beach 56. Fine tailings 57 are put above the
sand beach at the middle-low
section of the tailings pond. Some fine tailings are trapped in the sand beach
56. On top of the fine
tailings is the recycled water layer 58. The tailings concentration increases
with depth. Close to the
bottom of the tailings layers are the Mature Fine Tailings (MFT). (See "The
Chemistry of Oil Sands
Tailings: Production to Treatment" presentation by R.J. Mikula, V.A. Munoz,
O.E. Omotoso, and K.L.
Kasperski of CanmetENERGY, Devon, Alberta, Natural Resources Canada on
December 8, 2008 at the
International Oil Sands Tailings Conference in Edmonton, Alberta.) The
recycled water 41 is pumped
from a location close to the surface of the tailings pond (typically from a
floating barge). The fine tailings
are pumped from the deep areas of the fine tailings 60. Fuel 48 and oxidizing
gas 49 are injected into a
dryer / DCSG. The fine tailings 60 from the tailings pond or directly from the
froth treatment of the
extraction facility, are thickened in a thickening facility like a centrifugal
separator 31. These
commercially available units recover additional water 33 from the fine
tailings while increasing the solids
concentration in the thickened fine tailings 43. The dryer 50 described in
Figure 10 is a horizontal,
counter flow, rotating dryer. However, any available dryer / DCSG that can
generate gas and solids from
the MFT can be used as well. The fine tailings 43 turn into gas and solids as
the liquids within the tailings
flow are converted to steam. The solids 51 are recovered in a dry form. If
high temperatures are used,
the tailings can calcinated and de-hydrated where crystal water is removed
from the solids as well. This
is a function of the tailings chemical composition as well as the temperature
in the dryer. The dryer gas
discharge 47 is condensed in heat exchanger 61 to generate condensate 62. The
heat discharged from
the dryer is recycled back to the extraction process through a heat exchanger
61 to generate the hot
extraction liquid 57, mainly water with possible solvents. The generated
condensate from the
evaporated tailings can be added to the extraction liquid 63, possibly after
pH adjustment (not shown).
The dry fine solids 51 are combined and mixed with an in-situ oilsands
facility liquid stream 30 that
contains high levels of dissolved solids, mainly salts possibly with non-
volatile dissolved hydrocarbons.
The mixing of stabilized liquids 30 from the in-situ oilsands facility is
accomplished by contacting them
with the fine solids, which might have calcinated and de-hydrated levels that
are highly efficient in
stabilizing the liquids to a stable solid material that can be safely disposed
of in a land fill without the
9
Date Regue/Date Received 2023-06-19
risk of leaching to the surrounding environment. The dried dry solids from the
in-situ oilsands facility
tailings can contaminate the surrounding area by creating dust, especially in
windy conditions. By adding
the liquids and the solids together, the dust problem is solved as a stable
solid material is generated by
mixing the two flows and disposing of the generated solid in a land fill.
FIGURE 11 describes generating the dry solids material in the open mine
extraction facility in two steps
where in the first step the water and solvents are recovered for further use
in the extraction process by
the use of "dry" superheated steam and a second step where the dried solids
are further heated in the
presence of oxygen in direct contact with flame combustion where the solids
might be calcinated and
hydrates broken down and released, generating "water starving" solids capable
of solidify solids. A
Steam Drive Direct Contact Steam Generator (SD-DCSG) 30 (also called Dry Steam
Drive Dryer) is
integrated into an open mine oilsands extraction plant for generating the hot
extraction water while
consuming the fine tailings (the stream of liquids, mainly water and solvents
with high levels of non-
segregated fine suspended solids) generated by the extraction process. Flow 36
is superheated steam.
The steam flows into enclosure 30 which is a steam driven dryer. Fine Tailings
(FT) contaminated liquid
34, is also injected into enclosure 30 as the water source for generating
steam. The liquid component
within stream 34 evaporates and is transferred into steam, vapors and solids.
The remaining solids 35
are removed from the system. The generated steam 31 is at the same pressure
(less the flow losses
within the dryer 30) as that of the drive steam 36 but at a lower temperature
because a portion of its
energy was used to drive the liquid water 7 through a phase change. The
generated steam is also at a
temperature that is close to (or slightly higher than) the saturated
temperature of the steam and
solvents at the pressure inside the enclosure 30. The produced steam 33 is fed
into a heat exchanger /
condenser where the water and solvents are condensed and recovered and the
recycled back to the
extraction process. The steam 36 is flowing upwards in the rotating dryer 30
where low-quality liquid
water with solvents and solids from the open mine extraction facility 34, is
injected into the up-flow
steam. At least a portion of the injected liquid is converted into steam at a
lower temperature and is at
approximately the same pressure as the dry driving steam 36. The generated
steam can be saturated
("wet") steam at a lower temperature than the driving steam. A portion of the
generated steam 32 is
recycled through a compressing device 39. The compression is only designed to
create the steam flow
through heat exchanger 38 and create the up flow in the SD-DCSG 30. The
compressing unit 39 can be a
mechanical rotating compressor. Another option is to use high pressure steam
40 and inject it through
ejector to generate the required over pressure and flow in line 36. Any other
commercially available unit
to create the recycle flow 36 can be used as well. The produced steam, after
its pressure is slightly
increased to generate the recycle flow 36, and possibly after the contaminates
are removed in a dry
separator or wet scrubber to protect the heater 38, flows to heat exchanger 38
where additional heat is
added to the recycled steam flow 32 to generate a heated "dry" steam 36. This
steam is used to drive
the SD-DCSG / dryer as it is injected into its lower section 30 and the excess
heat energy within the
driving steam is used to evaporate the injected water and liquid solvents and
generate additional steam
31. There are several commercial options and designs to supply the heat 37 to
the process. The
produced steam 31 or just the recycled produced steam 32 can be cleaned of
solids carried with the
steam gas by an additional commercially available system (not shown). The
system can include solids
removal; this heat exchanger can be any commercially available design. The
heat source can be fuel
combustion where the heat transfer can be radiation, convection or both.
Another possibility can be to
use the design of the re-heat heat exchanger typically used in power station
boilers to heat the medium
/ low pressure steam after it is released from the high pressure stages of the
steam turbine to generate
the superheated steam 36. To further remove any organic contaminates in the
solids (or slurry discharge
from the rotating steam drive dryer) an additional combustor 10 is added. In
Figure 11 a rotating
combustor was added, however, any type of combustor, like a fluid bed, can be
added as well.
Date Regue/Date Received 2023-06-19
Hydrocarbon or carbon gas, liquid or solid fuel 11 is injected into the
rotating combustor 10 and burned
with pre-heated air 12. The solids 35 are heated within the kiln 10 and the
hydrocarbon and organic
contaminate is combusted in the oxygen environment within the enclosure 10. In
case the solids include
crystal water within their structure, this water will break out of the
molecules and leave the system in a
gas stage. Kaolin within the feed will be also converted to metakaolin and
other solids can be calcinated
due to the direct combustion process. Heat 37A is recovered in the heat
exchanger 19 from the
generated combustion gas and steam mixture 13. The generated solids 14 are
cooled in fluid bed
structure 15 or any other commercially available design 15 with a flow of
atmospheric combustion air
16. The cooled solids 17 are removed from the system for further use, like
stabilization of wet areas or
mixture with in-situ waste liquids.
FIGURE 12 describes another embodiment of the present invention which
describes generating the dry
solids material in the open mine extraction facility in two steps where, in
the first step, the water and
solvents are recovered for further use in the extraction process. A SD-DCSG
(Steam Drive Dryer) 11 with
a non-direct heat exchanger 13 heats the process water 14, with the combustion
of the NCG
hydrocarbons 17, as part of generating the driving steam 9. FT or MFT 7 are
injected into a Steam
Driven Dryer / SD-DCDG. In Figure 12, a vertical fluid bed SD-DCSG is
schematically represented. Any
other dryer designs can be used as well, like the horizontal rotating SD-dryer
or any other design. The
fine tailings 7, which contain water, solids and possibly solvents as well as
other hydrocarbons, are
mixed with the dry super-heated steam flow 9 that is used as the energy source
to transfer the liquid
phase in flow 7 to a gas (steam and hydrocarbon) phase by direct contact heat
exchange. The FT 7 solids
are removed in a stable form 12 for further combustion to remove, by
combustion, any organic
contamination and to generate water-starving solids, possibly dehydrated. The
produced steam 8 is
condensed in a non-direct heat exchanger / condenser 13. The water
condensation heat is used to heat
the extraction process water 14. With some tailings types, off gas like Non
Condensed Gases (NCG) or
light hydrocarbons that are breaking away due to the heat 17 are generated due
to the presence of
hydrocarbons, like solvents used in the froth treatment or oil remains that
were not separated and
remained with the tailings feed and did not condense with the condensing
vapors 13. The gas 17 is
burned, together with other fuel 20 like natural gas, syngas or any other
fuel. The combustion heat is
used, through non-direct heat exchange, to produce the superheated driving
steam 9 used to drive the
process. The amount of energy in the NCG hydrocarbons 17 recovered from
typical oilsands tailings,
even that from a solvent froth treatment process, is not sufficient to
generate the steam 9 to drive the
SD-DCSG /dryer. It can provide only a small portion of the process heat energy
used to generate the
driving steam 9. One option is to use a standard boiler 18 designed to
generate steam from liquid water
feed 19 from a separate source. Another option is to use a portion of the
produced steam condensate
23 as the liquid water feed to generate the driving steam 9. The condensate
will be treated to bring it to
BFW quality. Treatment units 24 are commercially available. Another option to
generate the driving
steam 9 is to recycle a portion of the produced steam 8. The recycled produced
steam 21 is compressed
22. Compression is needed to overcome the pressure drop due to the recycle
flow and to generate the
flow through the heater 18 and the SD-DCSG 11. The compression can be done
using a steam ejector
with high pressure additional steam or with the use of any available low
pressure difference mechanical
compressor. The recycled produced steam 21- possibly after additional
cleaning, like wet scrubbing, to
remove contaminates like silica- is indirectly heated by combustion heater 18.
The temperature in
enclosure 11 where the dry driving steam 9 heats the wet solids 7 to generate
dry solids is less than
typical combustion temperature, and the environment within enclosure 11 where
the heating takes
place is oxygen free and contains mainly steam, possibly with some solids. To
remove any non-volatile
remaining contaminates within the solids, the generated solids 12 are further
exposed to a direct
combustion heat in combustor 18 or a separate combustor. The combustion heat
is recovered for other
11
Date Regue/Date Received 2023-06-19
purposes like generating the driving steam. Another advantage is that the
solids leaving enclosure 11,
can be in a slurry form and still contain liquids like water and hydrocarbons
as they will be further dried
in the combustor 18 where any liquid remains will be evaporated and any
organic material remaining
will be combusted as the environment within the combustor includes combustion
gas that contains
oxygen. Additional effects due to the combustion is the potential of
generating "water starving" solids
31 by removing crystal water from the solids molecules and calcinations. Where
the feed contains clay
and kaolin, metakaolin will be generated in the combustion process. This
natural reaction is due to the
heat exposure. The generation of these reactions is mainly dependent on the
solids composition within
feed 7.
FIGURE 13 describes another embodiment of the present invention which
describes generating the dry
solids material in the open mine extraction facility in two stages where, in
the first stage, the water and
solvents are recovered with dry steam for further use in the extraction
process. And in the second stage
the remaining solids are further directly heated with combustion heat in a
combustion gas environment
where organic contaminations are combusted. Block A describes an open mine
oilsands extraction plant,
as described in Figure 10. Fine tailings 19A generated in the process,
possibly with additional fine tailings
14 like solvent extraction froth treatment fine tailings, are pre-heated in
heat exchanger Q2 to generate
heated fine tailings 7. (The term "Tailings" is used in this invention to
describe a liquid stream that
includes water, solvents and hydrocarbons with high levels of fine suspended
solids like fine clays.) The
heated fine tailings 7 are fed into enclosure 11 where they are directly mixed
with low pressure (close to
atmospheric pressure) dry super-heated steam 9 that converts most of the
liquids within the pre-heated
tailings 7 to vapor gas phase 8. Heat 04 is recovered from the vapor 8 while
condensing the vapor to
liquid phase 10, comprised mostly of water and solvents, and the liquid is
recycled back to the extraction
plant at Block A. The heat within vapor 8 is also used, directly or
indirectly, to heat the process
extraction water 52 to generate the hot extraction water 52A required in the
open mine extraction plant
in Block A. Enclosure 11 can be any direct contact dryer / evaporator design,
this includes a fluid bed
dryer design, rotating dryer, rotating internal paddles, venturi flash design,
or any other commercially
available design. Solids 12 are removed from enclosure 11 and injected into
enclosure 25 where they are
further directly heated with combustion gases. Enclosure 25 is a kiln design
that includes a heat
exchange section that can include chains 27 and/or lifting paddles 26 to mix
the solids 12 with the
combustion gas. The remaining water in solids 12 evaporates at the elevated
heat while any organic
remains within the solids 12 are combusted. Carbon or hydrocarbon fuel 23,
like natural gas, coal or
asphaltene, is injected into 23 and combusted within the rotating kiln 25. Due
to the high temperature
within the kiln 25, some types of solids lose their molecule crystal water and
can also go through a de-
hydration / calcinating process. The hot solids are cooled down while the
combustion air is heated 20.
The heat exchange between the hot solids and the air is enhanced by the use of
lifting paddles 22 and,
optionally, chains 27. The dry, possibly un-hydrated and possibly calcinated,
solids 21 are recovered for
disposal, possibly with additional mixing with liquid waste streams to
generate a solid stable material
that can be used for backfill. The combustion gases discharged from kiln 28
are cleaned in unit 29 to
remove solids 30 that can block the heat exchanger 32. Heat 01 is recovered
from the combustion gas
31. The heat Q1 is used to generate the driving steam Q3 or is used for pre-
heating the liquid feed 7 as
02 heat.
FIGURE 14 describes another embodiment of the present invention. Block A
describes an open mine
oilsands extraction plant as described in Figure 10. The thickened tailings
that include fine suspended
solids, water, solvents and possibly some levels of dissolved solids 7, are
pre-heated in heat exchanger /
condenser 7A and are injected into enclosure 11 where they are mixed with
superheated steam 9. The
dry superheated steam is evaporated liquid water and solvent from feed 7B. The
evaporation energy in
12
Date Regue/Date Received 2023-06-19
gas phase stream 8 is recovered in condenser 7A and then further recovered in
condenser 13 where the
remaining heat energy in stream 7C is recovered while heating the cold
extraction water 52. The
condensed liquids 10 are recycled back to the extraction facility. The solids
rich stream 12 from dryer 11
is directed to enclosure 20 that includes internal combustion. Carbon based
fuel 21 is combusted within
enclosure 20 with pre-heated air 22. The solids are exposed and mixed with the
combustion gas where
any organics that were not evaporated and removed by the steam in enclosure 11
are combusted. Any
liquids remains evaporate from the solids. Due to the high combustion
temperature, if the solids include
crystal water within their molecules, the water will break away generating
dehydrated "water starving"
solids like metakaolin. The hot solids 23 are cooled with the intake
combustion air 26 in heat exchanger
25 to generate pre-heated combustion air 22 and cooled solids 27 for disposal
or for further treatment
like mixing with a liquid waste stream to stabilizing these streams while
generating a solid material that
can be disposed of in a landfill or used for backfill. The heat from
combustion gas 24 from enclosure 20
is recovered in heat exchanger 29 to generate the driving steam 9. Enclosure
20 can be a rotating kiln or
any other available design.
FIGURE 15 describes another embodiment of the present invention. Block A
describes an open mine
oilsands extraction plant with a superheated steam extraction enclosure 11 as
described in Figure 14.
The solids rich discharge 12 from the steam dryer enters into a cyclone heat
exchanger 36 where the
solids are exposed to the heat from the discharged combustion gas from a kiln
30. The heated solids 37
enter the kiln 30 and are heated with combustion energy generated by combustor
35. Any remaining
organics are combusted in the kiln. Due to the high temperatures in the kiln
some solids can undergo
chemical reactions like the release of crystal water, calcinations or other
changes that are typical to the
particular solids composition. The hot discharged solids are cooled in a fluid
bed heat exchanger with
the feed combustion air 31. The produced solids 33 are disposed of, possibly
after being mixed with
additional liquid waste streams. To control the temperature, a portion of the
feed air is by-passed
directly to the cyclones 36. The combustion gas discharged from the cyclones
38 is cleaned in electric
precipitator 39 to remove solids within the combustion gas. Heat 041 is
recovered from the combustion
gas in heat exchanger 40. The heat can be used to generate the driving steam 9
and to pre-heat the
liquid feed 7. The combustion gas 45, after the combustion heat was recovered,
is released in stack 44.
FIGURE 16 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Extracting bitumen from minable oilsands ore while generating a liquid stream
that includes solids,
water and solvent.
Recovering a portion of the liquids from the solids, water and solvent stream.
Heating the solids and liquid stream with steam to evaporate a portion of the
water and solvent liquids.
Extracting heat from the gas phase while condensing the evaporated water and
solvent into liquid phase
and recycling the liquids back to the extraction process.
Heating the solids that include clay to combust any solvent or organic
contamination remains within the
solids and generating dry solids.
FIGURE 17 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Extracting bitumen from minable oilsands ore while generating a stream of
solids, water and solvent.
Recovering a portion of the liquids from the solids, water and solvent stream.
13
Date Regue/Date Received 2023-06-19
Heating the non-segregated solids and liquid stream with steam to evaporate a
portion of the water and
solvent liquids.
Condensing the evaporated water and solvent into liquid phase and recycling
the liquids back to the
extraction process.
Heating the solids that include clay to combust any solvent or hydrocarbon
remains within the solids and
generating dry solids.
FIGURE 18 describes a flow diagram of another embodiment of the present
invention. The process
includes the following steps:
Mining oilsands ore, and mixing the mined oilsands ore with extraction water.
Separating course solids for disposal.
Adding solvents to the froth to recover oil and remove asphaltene.
Recovering solvents and water while generating fine tailings that include fine
solids, water, solvents and
hydrocarbon remains.
Heating the fine tailings to evaporate at least a portion of the water,
solvents, and hydrocarbons to
generate a solids rich material.
Recovering the evaporated heat while condensing the evaporated water and
solvent into liquid phase
and recycling the liquids back to the extraction process.
Further heating the solids in the presence of oxygen to combust any solvent or
hydrocarbon remains
within the solids and generating dry solids.
Mixing the dry solids with disposal liquid or slurry from in-situ oilsands
facility to dry the excessive
liquids and generate a dust free, stable, solid material.
14
Date Regue/Date Received 2023-06-19
