Note: Descriptions are shown in the official language in which they were submitted.
CA 02665747 2009-05-12
USAGE OF OIL FACILITIES WASTE SLUDGE AND FINE TAILINGS WATER FOR
GENERATION OF HOT WATER AND STEAM FOR BITUMEN PRODUCTION
FIELD OF THE INVENTION
This application relates to a system and method for water recovery from waste
water like mature
fine tailing water in the oilsand industry. The recovered water can be used
during the bitumen
extraction process or for steam generation. The heat is used for heating the
process water or for
steam generation. The generated process waste is in the form of stable solid
material that can
support traffic. The recovered water can be used for steam generation in a
commercially -
available, non-direct prior art steam generator, as in OTSG and Boiler type
facilities. The
invention minimizes the need for settling fine tailing basins and enables a
sustainable tailing
practice of "reclaiming as you go". This means continually reclaiming the
excavated oilsand
areas as the mine progress to a new location.
The steam can be used for Enhanced Oil Recovery (EOR) facilities or for
separation of bitumen
from sand and water in open mining oil sand facilities. The water recovery
process includes solid
generation and separation in a ZLD (Zero Liquid Discharge), where a dry solid
waste or semi-
dry slurry is generated for effective disposal. The heat is recovered and used
to heat the
processed water, or to pre-heat boiler feed water for steam generation.
Tailing pond water is a by-product of the oil, water and sand separation
process. These ponds
are increasingly becoming a significant environmental problem, as the scale of
oil sand recovery
increases. Hundreds of ducks died last summer after mistakenly landed in
contaminated ponds in
northern Alberta. The tailing pond problem is continually escalating, as seen
in 1979 when
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there were tens of millions cubic meters of fine fluid tailings. Currently
there are close to eight
hundred million of cubic meters of MFT (Mature Fine Tailings). Some of the
oldest tailing
ponds are located (irresponsibly), in close proximity to the Athabasca River.
An extensive
rainfall in the area can cause these tailing ponds to overflow directly into
the river, with
devastating effects on the natural environment and on the settlement down the
river. The mature
tailing water contains suspended fine sediment (less than 40 microns). This
sediment can
include: clay, heavy metals, hydrocarbonslike bitumen, diluent, PAHs
(Polycyclic Aromatic
Hydrocarbons which occur in oil and are byproducts of burning fuels) and
Naphthenic Acids,
(surfactants found in all heavy oil), sulphate and sodium salinity. The PAHs
tend to settle out
with the fine sediments.
(See the February 2009 PEMBINA report "The waters that bind us", paragraph 2-
`Water and
oil sands development" by Peggy Holroyd and Terra Simieritsch.)
In Situ, oil Sands projects also generate large quantities of disposal water
and sludge from their
softeners as part of the facility water treatment plant, the steam generation
facility and the oil
separation process.
Another basic characteristic of an oil sands project is the use of heat and
steam. This is a
common characteristic for both the surface oil sands mining and the In-situ
oilsands plants.
In mining, the processed water is heated using steam. Steam is also used to
remove NCG and to
separate diluent from the sand and the water.
In-Situ EOR (Enhanced Oil Recovery) facilities use steam for underground
injection to separate
the oil from the sand and mobile it to the surface. Typical EOR In - Situ
facilities use SAGD and
CSS ("Huff and Puff) technologies.
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Most of the work done to resolve the oil sands tailing ponds problem, and
especially that of
mature fine tailing ponds, is separate from the existence of the oil sand mine
and the energy -
intensive extraction plant. Using this approach (of separating the cause from
the problem) will
merely defer the solution to the future, at which time oil facilities plants
will stop operating and
will probably be reclaimed. Such an approach can defer the mature fine tailing
reclamation costs
to the future. It is expected that the ERCB (Energy Resources Conservation
Board) will reinforce
actions to resolve the MFT problem. In a presentation done by the ERCB it was
mentioned that
"Fluid tailing volumes growing steadily.. no fluid tailings pond reclaimed
..and neither the public
nor the government is prepared to continue to accept commitments that are not
met and
increasing liabilities" (See "Oil Sands Tailings: Regulatory Perspective"
presentation by Richard
Houlihan and Haneef Mian from the ECRB, presented on December 10, 2008 at the
International
Oil Sands Tailings Conference in Edmonton, Alberta). The strategy currently in
use by Alberta
regulators is to force oil producers to implement at least a partial solution
for the problems
associated with oil sand tailing ponds.
(See: Tailings Performance Criteria and Requirements for Oil Sands Mining
Schemes- Directive
074 issued on February the 3rd 2009 by The Energy Resources Conservation Board
(ERCB), a
quasi-judicial agency of the government of Alberta. It can be viewed at:
http://www.ercb.ca)
A basic technical problem and/or disadvantage arises from delaying the
resolution of the MFT
problem to the future; where the oil is recovered, it would be uneconomic to
use my intensive
energy method, that uses extensive heat to resolve the fine tailing pond
problem. It produces hot
water and steam that is used by the oil sand production facility, with minimal
energy waste. In
the future, if the heat energy cannot be consumed by a producing oilsand
facility, the heat energy
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will be wasted. This will make the implementation of my invention to consume
the MFT pond
unfeasible. Other methods (like thickening, centrifuge, weather drying and
water capping) that
do not use intensive heat, can still be used, even without the operation of
oilsand niines. This
can be considered as a disadvantage of my invention compared to other
solutions for the MFT.
However, there is no commercially feasible solution currently in use that
completely resolves
the oil sand tailing problem in Alberta. There are several activities being
carried out by the oil
sand producers that are at different R&D stages. (See "Past, Present and
Future of Tailing" a
presentation by Mark Shaw of Suncor Energy, Alan Fair of Syncrude and Jonathan
Matthews of
Shell Canada Energy on December 7-10, 2008 at the International Oil Sands
Tailings Conference
in Edmonton, Alberta). The technologies considered there and tested by the
industry include:
Evaporation Dry and Freeze Thaw, In-Situ Densification (coke capping),
Thickened Tailing,
Accelerated Dewatering, Centrifuge MFT, MFT Water Capped lake and Consolidated
Tailing
(CT).
Currently, there is a large-scale centrifuge pilot project . The tailing ponds
require either
mechanical or chemical manipulation before subjecting the tailing fine clays
to the spin dry
cycle. To consolidate its tailings (CT), gypsum, a byproduct of the flue gas
system for scrubbing
out sulphur is added, possibly with lime. The theory assumes that the gypsum
interacts
electrostatically with the clay and the weight of the added sand squeezes out
the water. For the
thickening process, flocculants are used. The flocculants are organic polymers
that increase
settling to generate non-segregating tailings. The chemical treatment, in
which very long
molecules stick to different clays and interact mechanically, is enhanced
through the addition of
sand. Another activity uses C02. High priority CO2 is the by-product of a
hydrogen plant. The
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C02 results in very slight acidification that helps release calcium ions. Most
importantly, it also
has an electrostatic effect and reacts chemically. Whatever the process, the
resulting dry
stackable tailings have similar properties. The only commercially operated
options are the CT
and the MFT Water Capped Lake. A Field pilot is currently being done for the
Centrifuge MFT,
the Accelerated Dewatering and thickened tailings. Most of the methods used by
the industry
include natural (or accelerated) dewatering. The relay on dry weather in Fort
Mcmurray can be
tricky. For example, project execution personnel are well aware of the
challenges involved in
reducing the moisture content in the soil (to increase soil compaction) due to
unexpected
precipitation in that area. There is a chance that the precipitation in the
area will increase in the
future due to global warming. It is to be expected that drying the MFT will be
even more
challenging. The prior-art commercially available thickening tailing process
and the MFT
centrifuge or thickening process can be incorporated and in the invention to
increase the total
amount of treated tailing and solids removed.
The present invention is based on the opportunity of solving the waste sludge
or fine tailing
water problem through the use of intensive heat processes, while recovering
the water and heat.
It can then be used for steam generation. Otherwise, the processed water can
be heated for oil
extraction. Through this integrated approach, the tailing pond waste can be
treated using energy-
intensive processes (like DCSG - Direct Contact Steam Generation), to generate
steam and solid
wastes that can be disposed of in landfill with minimal environmental impacts.
Various patents have been issued, that are relevant to this invention. For
example, U.S. Patent
application No. 12/139,403, published on January 22, 2009 to Bozak et al.,
describes a method
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for treating tailing wastes. The method includes the use of jet pumps for
agitating the tailing to
separate during the carbon phase. The tailings are flocculated and dewatered.
U.S. Patent
4,969,520 Issued on November 13, 1990 to Jan et al., describes a method for
treating water for
the production of steam for EOR while generating sludge (which is composed
mainly ofcalcium
carbonate and magnesium hydroxide). It also describes the separation and
recovery of liquids
from the sludge with centrifuge, possibly using a flocculant. The solids are
disposed of in a
disposal land fill. U.S. Patent 6,036,748 Issued on March 14, 2000 to Wallace
et al., describes a
process for reducing the temperature and dissolving gases in black water,
which is generated by a
gasifier. The process includes flashing the water under low pressure, to
release the gas and
generate evaporation within the black water. This reduces the water
temperature while
generating water vapor. Some of the water vapor is later condensed and
recycled. The remaining
cooled black water is treated to remove the solids. U.S. Patent 6,706,199
issued on March 16,
2004 to Winter et al., describes a method and apparatus for withdrawing and
dewatering slag
from a gasification system, using a sloped conveying lock hopper with rotating
auger located in
the conveyer of the lockhopper. The solid slag converges upwards while
separating from the
water. U.S. Patent 6,027,056 Issued on February 22, 2000 to Maciejewski et
al., describes a
method for the assembly and slurrying of oil sand, containing oversize lumps
and water, while
removing the oversize lumps and producing slurry suitable for piping to a
separation facility.
It is a goal of the present invention to provide a system and method for the
use of waste water
while recovering the water and producing solid waste, to improve deep tar
extraction EOR
facilities, like SAGD or CSS.
It is another objective of the present invention to provide a system and
method for the use of
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discharged water and tailing water, while recovering the water and removing
solid waste to
improvement oil sand extraction facilities, like oil sand surface mining and
excavating.
These and other objectives and advantages of the present invention will become
apparent from a
reading of the attached specifications and appended claims.
DESCRIPTION OF THE INVENTION
FIGURE 1 shows a general block diagram of a prior art steam generation
facility for the oil
industry. These facilities are standard and commercially available. They
include two basic units
- a water treatment unit 1 and steam generating unit 2 that uses the treated
water. The water
treatment facility can be any type of commercially available facility, a warm
lime softener, an
RO (Reverse Osmosis), an evaporation based facility or ion exchange - based
facility. Feed
water 3 is treated to remove impurities. The particular facility in use and
the level of water purity
depends on the water 4 quality required by the steam generation facility, as
there is a significant
difference between the water requirements of OTSGs and boilers. The water
treatment plant 1
generates a stream of rejected water. This reject water is typical of the
water treatment process
being used. It can include sludge from the lime softeners, water from the
filters, ion exchangers
and polisher back-flashes, RO reject water, evaporator blowdown etc'. The
steam generation
plant can be an OTSG (Once Through Steam Generation) or Co-Gen that generates
80% steam 7.
It could also be a steam boiler that generates 100% steam 7. In the heavy oil
industry, it is
standard to use OTSG for in-situ facilities (like SAGD or CSS) and to use
steam boilers
producing 100% quality steam for the oil sand open mining facilities, as seen
in steam generation
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facility 2. Most of the water is recycled and used as an in-direct heat
transfer medium. Steam
generation facility 2 uses carbon based fuel or hydrocarbon fuel 5 and
oxidizer gas 6. In most of
the current oil sands projects, the fuel in use is natural gas and the
oxidizer gas is air. There are
also commercial projects in which the fuel is syngas, mainly CO. An additional
option is to use
the produced bitumen, possibly in the form of a slurry mixture. Typically, the
oxidation gas 6 is
air under atmospheric pressure. Another option is to use enriched air or pure
oxygen as the
oxidizing gas, (see patent application PCT/FR05/01745 for Mihel Conturie et
al, issued 6-July-
2005). However, oxycombustion requires the use of an air separation unit to
generate oxygen -
rich gas stream. This type of boiler can be used if the produced high
concentration C02
discharged from boiler 8 can be used as part of the process or for
sequestration (to offset the air
separation plant costs). Typically, the combustion gas 8 is released to the
atmosphere through the
steam generator stack at a temperature slightly higher than the dew -point, to
prevent corrosion.
The steam generation emits a stream of reject water. The quality and quantity
of the reject water
depends on the steam generation facility in question. For OTSG, 80% quality
steam is generated.
The remaining 20% water can be flashed in a few stages to recover water in the
form of low-
pressure steam. 9. Then, the remaining water is discharged as reject water,
preferably to disposal
wells (or to a separate ZLD facility, if required by environment regulators).
For boiler - based
steam generation, there is constantly water being discharged from the boiler
mud drums 9. The
produced steam 7 is used for injection into the underground formation, (in the
case of In-Situ
steam generation facilities) or for heating the processed water, the bitumen
slurry and the sandy
water. The steam is also used for flashing the diluent into the open mine
excavation - based oil
sand facilities.
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FIGURE 2 is a schematic view of the present invention for the generation of
hot water for oil
sand mining extraction facilities, with full tailing water recycling, to
achieve zero liquid
discharge with no fine tailing discharge.
Energy 1 is being injected to reactor 3. The energy should be in the form of
high temperature
combustion gas, typically in the range of 1300-400C. If it were to be
combusted inside the
reactor, it might become an oxidizing gas (like air) or a mixture of carbon or
hydrocarbon fuel,
(like natural gas or petcoke slurry). The energy is released in the form of
heat, to generate hot
combustion gas. Fine tailing water 5, possibly with high concentrations of
solids like clay,
hydrocarbons and other contaminants is injected into Direct Contact Steam
Generator reactor
3,where most of the water evaporates as it is converted to steam. There are
several feasible
designs for the reactor 3. The design can include a horizontal rotating
reactor, a fluidized bed
reactor and an up-flow reactor or any other reactor that can be used to
generate a stream of gas
and solids. The inventor filed a few patent applications for possible reactors
that may be used as
reactor 3. Possibility for reactors 3 include, but not limited to: US patent
application 12/037,703
filed by the inventor on February 26, 2008, US patent application 12/406,823
filed by the
inventor on March 18, 2009, US provisional patent application 61/092,668 filed
by the inventor
on August 28, 2008, and US provisional patent application 61/092,669 filed by
the inventor on
August 28, 2008. Any available DCSG design that can consume fine tailings can
be used as
reactor 3. A stream of hot gas 6, possibly with carried-on solids generated in
reactor 3, flows into
a commercially available solid-gas separator 20. Also, solids 4 can be
discharged directly from
the reactor 3, depending on the type of reactor used. The separated solids 22
and 4 are disposed
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of in a landfill. They can be mixed with tailing slurries to generate stable
material that can be
disposed of into an oilsand mine for re-claiming and support traffic. The
solid lean gas flow, with
steam from water flow 5, is converted to gas. Then, it is mixed with the
oilsand mine process
water 8 in vertical vessel 7. The processed water is heated due to direct
contact with the gas 21.
The water carried within the gas condenses and is converted to process water
8. The heated water
9 is typically at temperatures of 70C-90C. It is recycled back to the oil sand
mine, where it can
be mixed with the excavated oil sand, after passing through the breaker. The
pressure in the
system can range from slightly over 1 bar up to 50bar. The increase in
pressure augments the
efficiency of the water heating and recovery and reduces the needed facility
size. The down-side
of using high pressure, however, is that higher construction costs for the
facility will need to be
taken into consideration.
FIGURE 3 is a schematic view of one illustration of the present invention for
the generation of
pre-heated water that later can be used for steam generation in an oil sand
EOR facility or mining
extraction facility. The invention has full disposal water recycling, to
achieve zero liquid
discharge.
Energy 1 is introduced to Direct Contact Steam Generator reactor 3. The energy
may be in the
form of high temperature combustion gas, typically in the range of 1300C-400C,
or as a mixture
of carbon or hydrocarbon fuel, like natural gas or petcoke slurry and an
oxidizing gas like air.
The combustion inside the reactor releases the energy in the form of heat to
generate hot
combustion gas. Contaminated water 5, like MFT, are injected into reactor 3.
There, most of the
water is converted to steam leaving solids with low moisture content. There
are several
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possibilities for the design of reactor 3. The design can be a horizontal
rotating reactor, an up-
flow reactor or any other type of reactor that can be used to generate a
stream of solids and gas.
A stream of hot gas 6, possibly with carried-on solids generated in reactor 3
flows into
commercially available solid-gas separator 20. Solids 4 can also be discharged
directly from the
reactor 3, depending on the type of reactor used. The separated solids 22 and
4 are disposed of in
a landfill. The solids lean flow 21, (rich with steam from flow 5), mixes with
cooled, condensed
water 8 in direct contact vertical vessel 7. The solid remnants that
previously passed through
solid separation unit 20 and were carried on with the gas flow 21, are washed
with the heated
water 9. They are recycled back to the water treatment facility that
originally supplied water for
the steam generation facility (not shown). The condensing water 11 is cooled
in heat exchanger
10, while the heated water 13 is used as apre-heated water for steam
generation. The heat
extracted from gas flow 21, due to water condensation in vessel 7 and from the
NCG (Non
Condensable Gas) cooling, is a result of direct heat exchange with recycled
condensed water 8.
BFW (boiler Feed Water) 13 from a commercially - available water treatment and
steam
generation facility (not shown), flows through heat exchanger 10 to collect
heat and generate
pre-heated BFW 13. It is then used in the steam generation facility to
generate high-pressure
steam for EOR. For example, it may be used in an SAGD or for any other
function that requires
steam in an oilsand bitumen extraction facility. The temperature of the pre-
heated water is
dependant on the pressure in vessel 7. The pressure in the system can range
from slightly over 1
bar up to 100bar. The temperature of the preheated water, as well as the
overall thermal
efficiency of the system increases as the pressure increases, however this
advantage comes with
added facility costs. The system generates a stream of NCG 2 that can be
further treated through
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a process such as C02 separation for C02 sequestration. The C02 can also be
injected to an
underground reservoir, to recover oil or maintain the reservoir pressure. The
solids free NCG 2
can be used in the oil extraction process for slurry aeration or be released
to the atmosphere,
possibly after going through an expander to recover energy for compressing the
process oxidizer
gas (not shown).
FIGURE 4 is a schematic view of the present invention for the generation of
hot water for oil
sand mining extraction facilities, with full tailing water recycling to
achieve zero liquid discharge
with no fine tailing discharge and with S02 removal.
Energy 1 is being injected to reactor 3. The energy should be in the fonn of
high temperature
combustion gas, typically in the range of 1300-400C. If it were combusted
inside the reactor, it
might become an oxidizing gas (like air) or a mixture of carbon or hydrocarbon
fuel, (like sulfur
rich petcoke slurry). The energy is released in the form of heat, to generate
hot combustion gas.
Fine tailing water 5, (possibly with high concentrations of solids like clay,
hydrocarbons and
other contaminants), is injected into the horizontal counter flow Direct -
Contact Steam
Generator reactor 3. Inside, most of the water evaporates as it is converted
to steam. A stream of
hot gas 6, possibly with carried-on solids and S02 gas generated in reactor 3,
flows into a
commercially available solid-gas separator 20. Also, solids 4 can be
discharged directly from the
reactor 3, depending on the type of reactor used. The separated solids 22 and
4 are disposed of in
a landfill or mixed with the MFT to generate stable material that can be
disposed of in an oilsand
mine for re-claiming and support traffic. The solid lean flow 21, rich with
water converted to gas
from flow 5, is mixed with saturated water in vessel 12. Lime stone is
supplied as well, to
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capture the S02. The saturated water generates saturated NCG and steam 13. The
solid rich
water, including the generated gypsum, is recycled back to the DCSG 3,
whereeventually it is
released in solid form 4. The saturated, clean flow is injected to vessel 7
where it is used to heat
the processed water used for ore preparation 9. The processed water is heated
due to direct
contact with the gas 13. The water carried within the gas condenses and is
converted to
processed water 8. The heated process water 9 is typically at temperatures of
70C-90C. It is
recycled back to the oil sand mine, where it can be mixed with the excavated
oil sand after the
breaker. The pressure in the system can range from slightly over 1 bar up to
50bar. This increase
in pressure augments the efficiency of the water heating and recovery and
reduces the needed
facility size. The down-side with using high pressure, however, is that higher
construction costs
for the facility will need to be taken into consideration.
FIGURE 5 is a schematic view of an illustration of the invention, shown in
combination with a
commercially available steam generation facility 30. A prior art steam
generation facility 30
included a water treatment unit 1 and a steam generation unit 2. The
discharged water from water
treatment plant 10 and the discharged water from the steam generation facility
9 is injected to a
Direct Contact Steam Generator facility 15, where the discharged water is
subjected to a hot
pressurized combustion gas. The pressure can vary from lbar up to 70bar. The
hot gases are
generated from the combustion of carbon-based fuel 14 and oxidizer gas 13. The
fuel 14 can be
in the form of gas (like natural gas), liquid (like slurry or liquid
hydrocarbon) or solid, like pet-
coke or coal. Dry solids or semi-dry solids 16 in non-pumpable slurry form are
removed from the
produced gas flow 17. The discharged solids 16 can be disposed of efficiently
in a landfill. Gas
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flow 17 contains non-condensable gas and steam from water 12 in the form of
gas, possibly with
some carried-on solid remnants. The gas 17 is washed in vessel 20 through
direct contact with
saturated water 21. During this stage, additional steam can be generated. Make-
up water 22 is
continually added. The water can include lime and additional alkalis to remove
gas
contaminants, like S02. Solid rich contaminated saturated liquid - phase water
18 is recycled
back to the direct contact steam generator 15. There, it will be converted to
mainly gas 17 and
solids 16 for disposal. A saturated, solids free steam and non-condensed gas
mixture 23 is
generated. Stream 23 is mixed in pressurized vesse125 with the boiler feed
water 19 from water
treatment plant 1. The steam is condensed into water 24. The temperature and
pressure in vessel
25 is different in comparison to vessel 20, as the purpose of vessel 25 is to
recover the saturated
steam flow generated in vessel 20. Water 24, is at a lower temperature from
being saturated at
the partial pressure level inside vesse125. The heat from the non -
condensable gas and from the
condensed water vapor in gas flow 23 is recovered in direct contact with BFD
19, This is done
to generate heated boiler feed water 26. The heated BFW can be at a
temperature in the range of
50-200C. Based on the pressure inside vessel 25, the percentage of NCG will
vary and so will
the volume of BFW 19 that was injected to vesse125 from the water treatment
plant. This is done
to collect the heat and the water. The generated heated BFW 26 is pumped from
the bottom of
vessel 25 to the boiler 2, and is then pressurized and converted to steam at
steam generation
facility 2. The system may include pre-treatment of the BFW, to remove
dissolved gases that
have negative impacts on the steam generation facility, like traces of C02 or
S02 (not shown).
The steam generation unit 2 used for this process should be a common,
commercially available,
direct facility unit. This may include an OTSG or steam boiler, possibly with
economizer, air
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pre-heater, flue gas recycler or any other commercially available improvement.
Fuel 5 and air are
used in the steam generation facility 2 for steam generation, while generating
flue gases 8. The
steam generation facility generates high-pressure steam 7 and some reject
water 9. The reject
water is recycled back,along with the water treatment facility reject water
10, to the direct
contact steam generation unit 15. The high-pressure steam 7 can be used for
EOR and is injected
to an underground formation, as in SAGD or is used as the heat source in an
oilsand mining
plant operation.
FIGURE 6 is a schematic view of the present invention that includes
commercially available
steam generation facilities, with non-direct pre-heating of the BFW. Figure 6
is similar to figure
5, with a few differences. The prior art in figure 6 shows steam generation
that requires high
quality BFW, as in the case of a package boiler. In the boiler, condensed
water from the direct
contact mixture of the BFW with the saturated steam and NCG (non condensable
Gas) flow
cannot be used without complicated treatment before using the water in the
steam boiler 2. A
prior art steam generation facility 30 includes a water treatment unit 1 and a
steam generation
unit 2. The discharged water from the water treatment plant and the steam
generation facility 10,
are injected directly to a Direct Contact Steam Generator facility 15. There,
the discharged water
is subjected to a pressurized hot combustion gas. The hot gases are generated
from the
combustion of carbon-based fuel 14 and oxidizing gas 13. Dry solids or semi-
dry solids 16 in
non-pumpable slurry form are removed from the produced gas flow 17. The
discharged solids 16
can be disposed of efficiently in a landfill or in an excavation site, where
they can be covered
and re-claimed back into the environment. Gas flow 17 contains hot combustion
non-
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condensable gas and steam from the water that was converted to steam, with
possibly some
carried-on solid remnants. The gas 17 is washed in vessel 20 through direct
contact with
saturated water 21. During this stage, additional steam is generated. Make-up
water 22 is
continually added. The water can include lime and additional alkalis to remove
gas contaminants
like S02. A saturated, solids free steam and non-condensed gas mixture 18 is
generated. Heat
and water from stream 18 is recovered in heat exchanger 22 with BFW 19 from
the steam
generation facility. The heated BFW 23 is used in the steam generation
facility for steam
generation. The recovered liquid condensed water 26 is recycled back to the
water treatment
facility 1 for further treatment, before it can be fed into steam generation
facility 2. The
remaining non Condensable Gas, with some carry-on water vapor 27, can be
released to the
atmosphere, or sent for further treatment (like C02 sequestration). The
produced steam 7 from
the steam generation facility 2 can be used for many functions. It can be used
for underground
injection, (as in EOR), or to heat water or to separate bitumen from oilsand
slurry. As well, it
can be used to flash out diluent in open oil sand mine extraction.
FIGURE 7 is a schematic view of the present invention for the integration of
the present
invention with a commercially available steam generation facility and with non-
direct pre-
heating of the BFW. Figure 7 is similar to figure 6 with a few differences.
The prior art in figure
7 includes steam generation that requires high quality BFW. A prior art steam
generation facility
30 includes a water treatment unit 1 and steam generation unit 2. The
discharged water from the
water treatment plant and from the steam generation facility 10 are injected
directly to a Direct
Contact Steam Generator facility 15, where the discharged water is subjected
to a pressurized hot
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CA 02665747 2009-05-12
combustion gas. The hot gases are generated from the combustion of carbon-
based fuel 14 and
oxidizing gas 13. Dry solids, or semi-dry solids 16 in slurry form are removed
from the produced
gas flow 17. The discharged solids 16 can be disposed of efficiently in a
landfill or at the
excavation site where the solids can be covered and re-claimed by nature. Gas
flow 17 contains
hot combustion, non-condensable gas and steam from the water that was
converted to steam,
possibly with some carried-on solid remnants. The gas 17 is washed in vessel
20 through direct
contact with saturated water 21. During this stage, additional steam is
generated. Make-up water
22 is continually added. The water can include lime and additional alkalis to
remove gas
contaminants like S02. A saturated, solids free steam non-condensed gas
mixture 18 is
generated. The heat and water from stream 18 is recovered in vesse123 with
direct heat exchange
with recycled water 23. The recycled water 26 flows through liquid-liquid heat
exchanger 25,
with the BFW 19 (from the steam generation facility). The heated BFW 32 is
used in the steam
generation facility. The recovered liquid condensed water 31is recycled back
to the water
treatment facility 1, for further treatment before it can be fed into the
steam generation facility 2
and heated in heat exchanger 25. The remaining Non Condensable Gas, with some
carry-on
water vapor 24, can be released to the atmosphere. Or it can be sent to
undergo further
treatment, like C02 sequestration. The produced steam 7, from the steam
generation facility 2
can be used for underground injection as in EOR, to heat water and separate
bitumen from
oilsand slurry.
FIGURE 8 is a schematic view of an integrated facility of the present
invention with a
commercially available steam generation facility and EOR for heavy oil
production. The steam
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CA 02665747 2009-05-12
for EOR is generated using a lime softener based water treatment plant and
OTSG (Once
Through Steam Generator) steam generation facility. This type of configuration
is most common
in EOR done in Alberta. It is obtained from deep oil sand formations using
SAGD or CSS.
Produced water 3, is broken down inside separator facility to oi14 and water
5. There are many
methods of separating the bitumen from the water. The most common one uses
gravity. Light
hydrocarbons can be added to the product to improve the separation process.
The water, with
some oil remnants, flows to a produced water de-oiling facility 6. In this
facility, de-oiling
polymers are added. Waste water, with oil and solids, is rejected from the de-
oiling facility 6. In
a traditional system, the waste water would be recycled or disposed of in deep
injection wells.
The de-oiled water 10 is injected into warm lime softener 12, where lime,
magnesium oxide and
other softening chemicals are added 8. The softener generates sludge 13. In a
standard facility,
the sludge is disposed of in landfill. The sludge is semi-wet and hard to
stabilize. The softened
water 14 flows to a filter, 15, where filter waste is generated 16. The waste
is sent to an ion-
exchange package 19, where regeneration chemicals 18 are continually used and
rejected with
carry-on water as waste 20. In a standard system, the treated water 21, flows
to an OTSG where
approximately 80% quality steam is generated 27. The OTSG typically uses
natural gas 25 and
air 26 to generate steam. The flue gas is released to the atmosphere through
stack 24. Its
saturated steam pressure is around 100bar and the temperature is slightly
greater than 300C. The
steam is separated in separator 28, to generate 100% steam 29 for EOR and blow-
down water 30.
The blow down water can be used as a heat source and also to generate low
pressure steam. The
steam, 29 is delivered to pads, where it is processed and injected to the
ground through injection
well 53. The production well 54 produces an emulsion of water and bitumen 3.
In some EOR
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CA 02665747 2009-05-12
facilities, injection and production occur in the same well, where the steam
is 80% quality
steam 27 . The steam is then injected to the well with the water. This is
typical of the CSS pads.
The reject streams include the blow down water from OTSG 33, as well as the
oily waste water,
solids and polymer remnants from the produced water de-oiling unit. This also
includes sludge
13 from the lime softener, filtrate waste 16 from the filters and regeneration
waste from the Ion-
Exchange system 20. The reject streams are collected 33 and injected to Direct
Contact Steam
Generation 34. Additional water 32, from any available water source, can be
added. The energy
source can be a gas, liquid, solid, carbon or hydrocarbon - based fuel 36 and
oxidizing gas, (like
air) 35. The DCSG can be vertical, stationary, horizontal or rotating, as
schematically drafted in
scheme 34. Dry solids 37 are discharged from the DCSG, after most of the
liquid water is
converted to steam. The combustion gas and steam 38 temperature can vary
between 120C to
300C. The pressure can vary between lbar to 50 bar. The solid lean gas is
injected into vessel 41,
where the gas is washed with saturated water 42 to remove the solids remnants.
The water can
include lime to remove sulfur gas. Make-up water 47, can be added to the
vessel 47. Solid rich
water, possibly with gypsum (generated from the reaction between the sulfur
and the lime), is
continually removed from the bottom of vessel 41. It is recycled back to the
DCSG, where the
solids are removed in dry or semi-dry form 37. The liquid water is converted
back to steam 38.
The solid - free saturated steam and combustion gases 43 flow to a second
vessel 45. In this
vessel, the steam condensates to liquid water 44. Then, it is cooled due to
direct contact heat
exchange with the BFW (Boiler Feed Water). Water 21 is generated by the water
treatment
facility 1 and partially by the ion-exchange system 19. The heated water, 22
can be sent back as
pre-heated BFW to the OTSG, to generate 80% quality steam. Or, it can be
recycled back to
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CA 02665747 2009-05-12
water treatment facility 40, where it is added to de-oiled produced water 10.
FIGURE 9 is a schematic view of an integrated facility with a commercially
available steam
generation facility 1, for open mining at oilsand facility 60. The steam for
the bitumen extraction
is generated with commercially available boilers 17, that include steam and
mud drums. The
water for steam generation is produced using a standard, commercially
available water treatment
facility that is based on ion exchange and polishers. Raw water 3 flows to de-
mineralized water
clarifier and filter 2. The filtered water 6, flows to cation reactor and de-
gasifier 7. The water
flows to anion reactor 11. From the anion reactor, it goes to a mixed bed
polisher 14, to generate
de-mineralized BFW quality water 16. Chemicals arecontinually supplied during
the process, to
remove minerals. In the process, reject and backwash water is continually
generated 5, 9, 12, 15.
The reject water contains minerals and water treatment chemicals. The reject
water is collected
and injected to the vertical up-flow, cold fluid bed, direct contact steam
generator 30. Fuel 27
and oxidizer are injected to the bottom of fluidized bed steam generator 30.
The water 26 is
sprayed into the steam generator 30, above the combustion zone. The sprayed
water is composed
of: water treatment facility 1 reject water, boiler blow-down water 22 and
reject water 47 from
oilsand mine extraction facility 60. The reject water includes tailing water
and possibly
hydrocarbon contaminants. The liquid water is converted to steam and carries
most of the solids
upwards, where they are discharged at the top of the vessel, as a solid - rich
stream of gas 31.
Some of the cooler discharged gas, at a temperature range of 150C-400C, is
recycled back to the
bottom of the vertical steam generator 30, to maintain the cold fluid bed
below the combustion
zone. It reduces the temperature and increases the up-flow stream in vessel
30. Solids 36 are
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CA 02665747 2009-05-12
removed in dry form from the solid - rich gas flow 33. The solid lean gas flow
35, is washed in
tower 38 with saturated water to remove any solid remnants. Sulfur gas can be
removed as well
with the use of lime. After most of the solids have been removed, the solid
rich water is recycled
back to steam generator 30. Make-up water is added to vessel 38, to maintain
saturated liquid
water level. The saturated stream of steam and NCG 40 flows to vessel 42,
where heat is
recovered using direct - contact cold water circulation 43. The recovered heat
goes in through
liquid heat exchanger 44. The heat increases the temperature of the treated
BFW (Boiler Feed
Water) in steam generation facility 1. The heated BFW temperature can be in
the range of 70C-
200C, depending on the partial steam pressure of vessel 42. The heated BFW 23
is fed to the
boiler steam generator 17, to generate high pressure steam for oil sand mine
and bitumen
extraction facility 60.
FIGURE 10 is a schematic view of the integrated facility of the present
invention for open mine
oilsand extraction plant 60, using commercially available steam generation
facilities and a
gasifier for syngas generation. The steam for bitumen extraction can be
generated using a
commercially available boiler 12, an OTSG 20 or a gasifier 54. The steam
boiler 12 and the
gasifier 54 generate steam from BFW water 9. The steam is used for heating
purposes, through
heat exchangers in a close cycle. This minimizes the size of the heat
treatment facility 1 required
to generate high quality BFW, as it will have to produce only start-up and
make-up water. The
water treatment plant 1 for the generation of BFW is commercially available in
a package. The
water 2, for production of BFW in the water treatment package is fresh water
(not processed
water from bitumen extraction 60). For example, river water can be used
without oil traces. The
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BFW 16 is fed to the steam boiler 12 facility. Some of the BFW 11 is fed to
the gasifier unit 54.
The produced steam 15 from the steam boiler 12 and from the gasifier 55 is fed
to oil extraction
plant 60, to heat the processed water. The condensed water 17 is recycled back
from oilsand
plant 60, as a BFW to be re-used at the boiler 12 and the gasifier 54. The
oilsand extraction
facility requires processed steam, as well. The processed steam is used in
direct contact with the
process flow. For example, for froth de-aeration or for flashing out light
carbons and diluent.
The steam generated through OTSG can use much lower quality water than boiler
12 and gasifier
54. The generated 80% steam 29, is separated in separator 30 to generate 100%
steam 31 and
blow-down water 18. The 100% steam and the blow-down water 18 are both used in
the oilsand
open mine facility 60. The blow-down water 18 is mixed with process water,
from facility 60,
with the pressure dropping to generate processed hot water at 80-90C for tar
separation. Some
processed water 19 from facility 60 can be sent to water treatment plant 24.
The use of fresh
water, 27 instead of the processed water 19, is preferable to reduce the water
treatment plant 24
requirements, as it eliminates the oil removal stage. The water treatment
plant is tailor - made to
the quality of the source water. If fresh river water w as used, the plant, 24
would be very
simple, as the OTSG can use this type of water with minimum treatment (I.e.-
filtering, oxygen
removal and adding anti scaling additives). If the water used by the water
treatment plant is
processed water, then the water treatment system 24, will be similar to a
typical water treatment
plant used in EOR facilities, like SAGD, described in Fig. 8. The gasifier 54,
can be any type
that is commercially - available. The use of a gasifier, with a water
quenching bath is
preferable. That is because the integration of gasifier 54 with DCSG (Direct
Contact Steam
Generation) 46 eliminates the problem of treating the "black" and "grey" water
45. This is
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CA 02665747 2009-05-12
because the gasifier quenching water 45, is converted to steam and the solids
are discharged in a
dry form and are ready for landfill. Water - quenching gasifiers were
developed by Texaco from
the 1950'. Currently, they are available from GE. The gasifier, 54 uses oxygen
enriched gas 56
and carbon fuel 57. The carbon fuel can be petcoke or coal slurry. In the
gasifier, the exothermic
reaction heat generates high pressure steam 55 from BFW 11. The pressurized
hot discharged
syngas 47, flows to DCSG 46, where it is mixed with solid rich water to
generate a stream of gas
44, with dry solid discharge 48. The water injected to the DCSG 46 may be the
solid rich
quenching water from gasifier 54, the concentrated fine tailing water 43 from
the oilsand
bitumen extraction facility 60. It can also be the recycled saturated water
42. The solids are
discharged from the DCSG through pressure chambers 50 and 51, to reduce the
atmospheric
pressure. Heat exchanger 49 can be used to recover heat from the discharged
solids. The solid
lean gas flow 44 is treated in vessel 40, where the solid remnants are
scrubbed from the gas flow.
The liquid water in vessel 40 is saturated so that additional steam is
continually generated. Make-
up water, 41 is added to vessel 40, to generate a saturated stream of solid -
free syngas and steam
39. The heat and water is recovered from the saturated stream 39 in vessel 37.
This is done
through direct contact between the treated water 25 and the up-flow saturated
gas 39 in vessel
37. The steam is converted to water and washed from the syngas, generating
cooler and dryer
syngas 36 and hot water 28, that is used in the OTSG 20 to generate 80% steam.
To avoid the
direct use of the water that recovers the heat from the syngas in the OTSG, a
heat exchanger can
be added (not shown). The syngas is treated using various commercially -
available methods in
facility 35. Sulfur, mainly H2S can be removed from the syngas. Hydrogen can
be generated for
use in oil upgrading. The sweet syngas 34, composed mainly of CO, may be used
to replace
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CA 02665747 2009-05-12
natural gas as the fuel source in the OTSG 20 and steam boiler 12. It can also
be used to generate
electricity and steam in a co-generation facility (not shown).
FIGURE 11 is a schematic view of the invention, with an open mine oilsand
extraction facility,
where the hot process water for the ore preparation is generated from
condensing the steam
generated from the fine tailings. A typical mine and extraction facility is
briefly described in
block diagram 1(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
Oil sand 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. Oversize
particles are rejected and
removed to landfill. The ore mix goes through slurry conditioning, where it is
pumped through a
special pipe line 7. Cheniicals and air are added to the ore slurry 8. In the
invention, the NCG
(Non Condensed Gas) 58 that are released under pressure from tower 56 can
replace the injected
air at 8 to generate aerated slurry flow. The conditioned aerated slurry flow
is fed into the
bitumen extraction facility, where it is injected into a Primary Separation
Ce119. 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 tailing are separated in separator 13. The fine tailing flows 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
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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 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 to tailing
processing area 60. The
fine and coarse tailings can be combined or removed separately (not shown) to
the tailing
process area 60. In unit 60, the sand and other large solid particles are
removed and then put back
into the mine, or stored in stack-piles. Liquid flow is separated into 3
different flows, mostly
differing in their solid concentration. A relatively solids - free flow 62 is
heated. This flow is
used as heated process water 57 in the ore preparation facility, for
generation of the oilsand
slurry 6. The fine tailing stream separates into two sub streams. The most
concentrated fine
tailings 51 are mixed with dry solids generated by the DCSG, to generate a
solid and stable
substrate material that can be put back into the mine and support traffic. The
medium
concentrated fine tailing stream 61 flows to DCSG facility 50. Fuel 46 and
oxidizing gas 47 are
used in the facility to generate a hot combustion gas. The combustion can be
at full or partial
combustion (like in a gasifier). Some of the combustion energy in facility 50
can be used to
generate "standard" steam in an heat exchanger (like in a boiler or gasifier
with a radiation heat
exchange section). The discharged combustion gas energy is used to convert the
fine tailing 61
water into a dry or semi dry solid and gas stream. The temperature of the
discharged solid - rich
gas can vary from 150C to 400C. The solids are separated from the gas stream
in any
commercial available facility 45. This facility can include: cyclone
separators, centrifugal
separators, mesh separators, electrostatic separators or other combination
technologies. The
solids lean gas 52 flows into tower 56. The gas flows up into the tower
through a set of trays,
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CA 02665747 2009-05-12
while the solid carried-on remnants are scrubbed from the up flowing gas
through direct contact
with the liquid water. The water vapor that was generated from heating the
fine tailing in the
DCSG becomes condensed and is added to the down-flowing extraction water
process 57. The
presence of small amounts of remaining solids in the hot process water is
acceptable. That is
because the hot water is mixed with the crushed oilsand 3 in the breaker
during ore preparation.
The temperature of the discharged hot water 57 is in between 70C-95C,
typically in the 80C-
90C range. The hot water is supplied to the ore preparation facility. The
separated dry solids
from the DCSG are mixed with the concentrated slurry flow from the tailing
water separation
facility 60. They are used to generate stable solid waste that can be returned
to the oilsand mine.
Any commercial available mixing method can be used in the process: a rotating
mixer, Z type
mixer , screw mixer, extruder or any other commercially available mixer. The
slurry 51 can be
pumped to the mixing location, while the dry solids can be transported
pneumatically to the
mixing location. The NCG (Non Condensed Gases) 58, that were not condensed by
the process
water are discharged from the top of the tower 56. It replaces the air and can
be injected into the
slurry at 8 for aeration. It can also be expanded on a turbo expander to
recover excess energy.
Further, it can b treated to remove gas fractions (like recover C02 for EOR or
sequestration).
Otherwise it can just be released to the atmosphere. The described
arrangement, where the fine
tailing are separated into 2 streams 61 and 51, is intended to maximized the
potential of the
process to recober MFF. It is meant to maximized the convertion of fine
tailings into solid waste
for each weight unit of the supplied fuel source. The system can work in the
manner described
for tailing pond water recovery. The tailing pond water is condensed into hot
water generation
57, without the combination of the dry solids 53 and tailing slurry 51. The
generated dry solids
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CA 02665747 2009-05-12
53 are a "water starving" dry material. As such, they are effective in the
process of drying MFT
(Mature Fine Tailing), to generate trafficable solid material without relying
on weather
conditions to dry excess water. The water affinity of the dry solid composite
released from the
DCSG 50 is dependent on its composition and particle size. The most effective
water affinity
material are solids that, with the presence of water, create crystals with
water molecules. The
gypsum belongs to this group of materials. If highly sulfurous material fuel
is used in the DCSG
(like petcoke), lime can be added to remove the S02 and generate gypsum. The
gypsum will lose
its crystal water when it undergoes the high temperatures inside the DCSG, as
its water will be
converted to steam. This will improve the efficiency of the capability of the
dry discharged solids
to solidify a MFT slurry to a stage where it can carry traffic. (See U.S.
Patent No. 6,960,308
called "Endothermic Heat Shield Composition And Method For The Preparation
Thereof'
issued to the inventor on November 1, 2005).
FIGURE 12 is a schematic view of the invention, with an open mine oilsand
extraction facility,
where the hot process water for the ore preparation is generated from
condensing the steam
produced from the fine tailings. As shown in Fig. 11, a typical mine and
extraction facility is
briefly described in a block diagram. The tailing water from the oilsand mine
facility 1 is
disposed of in a tailing pond. The tailing ponds are built in such a way that
the sand tailings are
used to build the containment areas for the fine tailings. The tailing sources
come from
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 solid settling
and recycling of warm water . Another source of fine tailings are the Froth
Treatment Tailings,
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CA 02665747 2009-05-12
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 tailing pond. The sand separates
from the tailing
and generates a sand beach 56. Fine tailings 57 are put above the sand beach
at the middle-low
section of the tailing pond. Some fine tailings are trapped in the sand beach
56. On top of the fine
tailing is the recycled water layer 58. The tailing concentration increases
with depth. Close to the
bottom of the tailing layer are the MFT (Mature Fine Tailings). (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
tailing pond,
(typically from a floating barge). The fine tailings that are used for
generating steam and solid
waste in my invention are MFT. They are pumped from the deep areas of the fine
tailings 43.
Fuel 48 and oxidizing gas 49 are injected in a DCSG. MFT (Mature Fine Tailing)
43 is pumped
from the lower section of the tailing pond and is then directed to the DCSG
50. The DCSG
described in figure 12 is a horizontal, counter flow rotating DCSG. However,
any available
DCSG that can transfer the MFT to gas and solids can be used as well. Under
the heat and
pressure inside the DCSG, the MFT turn into gas and solids, as the water
converts to steam. The
solids are recovered in a dry form or in a semi-dry, semi-solid slurry form
51. The semi-dry
slurry form is stable enough to be sent back into the oilsand mine without the
need for further
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CA 02665747 2009-05-12
drying tosupport traffic. The produced steam 14, needed for extraction and
froth treatment, is
generated by a standard steam generation facility 36 from BFW 37, fuel gas 38
and air 39. The
blow-down water 20 can be recycled to the process water 20. By continually
consuming the fine
tailing water 43, the oil sand mine facility can use a much smaller tailing
pond as a means of
separating the recycled water from the fine tailing. This is cost effective
and it is the simplest
way to do so, as it does not involve any moving parts (in contrast to the
centrifuge or thickening
facilities). This solution will allow for the creation of a sustainable, fully
recyclable water
solution for the open mine oilsand facilities.
FIGURE 13 is a schematic view of gasifier unit and an open mine oilsand
extraction facility,
where the hot process water is heated in direct contact with the syngas. In
this figure, the MFT
33 is not converted into steam and solid, but is just mixed with the dry
solids generated by the
system 15. Gasifier 5, with water quenching bath at its bottom generates HP
steam 3, from BFW
4 that is supplied from water treatment plant (not shown). The gasifier
generates syngas from
partial combustion of low grade fuel, like petcoke or coal 1. The hot syngas
is mixed with water
in an up-flow direct contact steam generator 10. ( Refer to U.S. provisional
patent application
61/092,668, filed by the inventor on August 28, 2008). The dry solid particles
are removed from
the gas flow with cyclone and electrostatic separator 16. The solid lean
syngas stream flows to
vessel 23, where it is mixed in direct contact with cold extraction water 27
to heat the water to
80C-90C. The hot process water 24 is used in the ore preparation facility 40.
The dry solids 15,
generated by gasifier 5 are mixed with MFT 33 that is pumped. It is removed
from the tailing
pond to generate stable material that can be used to support traffic. In the
process, water from the
MFT is not recovered. Instead, it is used to generate steam or hot process
water. This
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CA 02665747 2009-05-12
arrangement is less effective in recovering MFT, but much easier to implement.
FIGURE 14 is a schematic view of the invention, with open mine oilsand
extraction facility,
where the hot process water for the ore preparation is generated from
condensing the steam
generated from the fine tailings. The tailing water from the oilsand mine
facility 43 is disposed
of in a tailing pond. Fuel 3, possibly petcoke, coal or asphaltin slurry and
oxidizer 4 (like air) are
fed into and combusted inside a horizontal parallel flow DCSG 1. Concentrated
MFT 2 is
injected to the DCSG, as well. The MFT is converted to gas, steam , and
solids. The solids are
removed in a solid gas separation 7 where the solid lean stream is washed in
tower 10 by
saturated water. In the tower, the solids are washed out and removed. S02 can
be removed from
the saturated water with lime. The solid rich discharge flow 13 can be
recycled back to the
DCSG or to the tailing pond. The amount of heat recovery is limited while
maintaining heat
exchanger 17 at a reasonable size. Heat is recovered from saturated gas 16.
Steam is condensed
to water 20. The recovered heat can be used for pre-heating the BFW (not
shown) or for use in
any other process. The condensed water 20 can be used as hot process water and
can be added to
the flow 24. The remaining heat is recovered and water vapor is washed. It
becomes liquid water
in vessel 21 because of direct contact with cold process water 25. The NCG 36
can be used as
part of the process for slurry aeration (not shown). The fine tailings 32 are
pumped from the
tailing pond and separated into two flows by a centrifugal process 14. This
unit separates the
fine tailing into two components: solid rich 30 and solid lean 33 flow. The
centrifuge unit is
commercially available and was tested successfully in two field pilots (See
"The Past, Present
and Future of Tailings at Syncrude" presentation by Alan Fair from Syncrude on
December 7-10,
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CA 02665747 2009-05-12
2008 at the International Oil Sands Tailings Conference in Edmonton, Alberta).
The solid lean
flow can contain less than 1% solids. The solid rich flow is thick slurry
("cake") that contains
more than 60% solids. The solid lean flow is recycled back to a settling basin
(not shown) and
eventually used as a process water 35. The solid concentration is not dry
enough to be disposed
of efficiently and to support traffic. This can be solved ( shown in my
invention) through mixing
it with the "water starving", virtually dry solids generated by the DCSG and
discharged from the
gas-solid separator. The mixing of the dry solids and the thick slurry can be
achieved through
many commercially available methods. In this particular figure, the mixture
loaded with the
stable solids for disposal on a truck 28. This is done by a screw conveyer 29
where the slurry 30
and the dry material 8 are added to the bottom of a screw conveyor and mixed
by the screw. The
produced solid material 27 can be backfilled into the oilsand mine excavation
site. In this
particular figure, there are two options for supplying the fine tailing water
to the DCSG. One is
to supply the solid rich thick slurry 30 from the centrifuge unit 31. The
other is to provide the
"conventional" MFT, typically with 30% solids, as pumped from the settlement
pond. For option
1, the overall amount of recovered MFr will be larger, while the heat
efficiency and the amount
of heat recovered from each ton of fuel will be smaller (vice versa for option
2).
FIGURE 15 is a schematic view of the invention, with an open mine oilsand
extraction facility,
where the heat source is a gasifier with maximization of the MFT recovery. The
partial
combustion is taking place inside the gasifier. The hot syngas 5 flows to the
horizontal parallel
flow DCSG 1. Concentrated MFT 2, is injected to the DCSG, as well. The MFT is
converted to
gas, mainly steam, and solids 6. The solids 8 are removed in a solid gas
separation 7. The solid
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CA 02665747 2009-05-12
lean stream flows through heat exchanger 11, where it heats the process water
12 indirectly
through a heat exchanger. Sour condensing water 13 is removed from the bottom
for further
treatment. The syngas 17 is further treated. This treatment can include the
removal of the H2S in
an amine plant. It can also include generating hydrogen and CO based gas to
replace the natural
gas (not shown). The fine tailings 14 are pumped from the tailing pond and
separated into two
flows through a specific separation process. This separation can be based on a
centrifuge or on a
thickener, (like a High Compression Thickener). This unit separates the fine
tailings into solid
rich 16 and solid lean 2 flows. The solid lean flow is fed into the DCSG 1
where dry solids are
generated and removed from the gas-solid separator. The solid rich flow 16 is
mixed with the dry
solids 8 in a screw conveyor, to generate a stable material 27.
FIGURE 16 is a schematic view of the invention, with an open mine oilsand
extraction facility,
where the hot processed water for the ore preparation is generated from
condensation of the
steam generated from the fine tailings. The tailing water from the oilsand
mine facility 43 is
disposed in a tailing pond. Fuel 5, (possibly petcoke, coal or asphaltin
slurry and air 6) is
injected and combusted inside a horizontal counter flow DCSG 7. MFT flow 9 is
injected to the
DCSG. The MFT is converted to gas, mainly steam, and solids. The solids are
removed directly
from the DCSG. The solid lean discharge stream 10 is washed in tower 13 by
saturated water. In
the tower, the solids are washed out and removed. S02 is removed by lime. The
solid - rich
discharge flow 11 with the generated gypsum is recycled back to the DCSG 7.
The saturated gas
15 flows to vessel 20, where it is mixed with the cold process water 22
recycled from the tailing
pond. The generated hot water is used in ore preparation unit 40. The
pressurized NCG from
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CA 02665747 2009-05-12
vessel 20 can be used in the process (not shown) or expanded on a turbo
expander 18 to recover
part of the energy used for compressing the oxidizing air 18. The fine
tailings 25 are pumped
from the tailing pond and separated into two flows by a centrifuge process.
This unit separates
the fine tailings into solid rich flow 9 and solid lean flow. The centrifuge
unit is commercially
available. The solid lean flow is recycled back to process water 22. The solid
concentrated flow 9
is mixed with the dry solids 4 to generate stable disposal material.
FIGURE 17 is a schematic view of the invention, with an open mine oilsand
extraction facility,
where the hot process water for the ore preparation is generated from
condensing the steam
generated from the fine tailing through a heat exchanger. Fuel 3 and oxidizer
4 are mixed and
combusted inside a horizontal parallel flow DCSG 1. MFT 2 is injected to the
DCSG as well.
The MFT is converted to gas, mainly steam, and solids. The solids are removed
in a solid gas
separation 7. The solid lean stream is washed in tower 10 by discharged fine
tailing water from
the oilsand extraction facility. This tailing water collects the heat from the
up-flow gas and the
condensed saturated water 17. The hot tailing water 13 exchanges heat with
heat exchanger 12,
where the water heats the cold process water while cooling the tailing water.
The cooled tailing
water 15 is directed to the tailing pond where its acidity (especially due to
the S02 gas generated
by the fuel combustion) might accelerate the steeling time for the fine
tailings, thus decreasing
the tailing pond size. The hot process water is used for the ore preparation.
The pressurized NCG
17 is used for aeration of the slurry.
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CA 02665747 2009-05-12
EXAMPLE 1: The following flow table is a simulation of a rotating direct -
contact steam
generator, as described in FIG. 14 for 50bar pressure. The simulated flow
shows the flow 6 being
discharged from the pressurized rotating drum. The heat source is coal slurry,
internally
combusted. The water source is settlement pond water. The discharged steam,
flue gas and solids
mixture is described in the following table:
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CA 02665747 2009-05-12
Cmrka~ CoIJ'icxj~] IReactar_GUtletClut IX-01Sn0 r+~ rnkr-c oaoo30 021
V~Ff~C 1) 9135J3 r s f~ ora7~ D.oo 0.00
T [L,, 400.0t7~ILJ~Q.~IOFIGE . . .. 0.00804' 4.39
_, .. ..... :=na.t[~In OCC>a47 025
lkpd] 5555.00 rrrRacU+vCtAVlLFE o.aoazi oai
hb!2F~~r ~k niDe h] 545.42 ,ae W., s,nFr aami4 ocse
. ., -wr~r.S~1F'17E O.W OAGS
N1dSSFj> [kg,h] 11722.72 r-l-Fn.,L a_oo ono
..... . E'rti.f3:r . . D06aD0
Vokr.~flow{m3tr) 504.5iy F1~wre oiro oai
`,t t3q~loY n~F 6 v[m3,Fr] 12. fi- , wrnnF ! Dno ~.oim
0.70
StdCc75VCY ntflow (5 ,C.,^'C'] 3.i~11E+5 u.FU, u:arõoE 0.100129
r ~:,cs G qcuC~/+7 '' E~;G3~T
WAT[it 0 ~3[e2 eskw 351-
Er#~-"g}[W"] 3~+I suz~~ ~lo;rx 012129 2495.79.. ... tpP^J "7FY1 Xt[~ 0.00658
77,17
H[k.akral] 250~.i v ~ 01OW38 3915z
o ooo>.
S [r ~k.m~ ] '39.A7o ar GY,4 ooo2ov;zs.9~~le Ulah'el~t 21 av ~c 3Z=~ 0.000766
95
exõ rrF s,a,~ 000 000
~es~ars }[ ~ m't 23.2331 yaMa, Hrk:JC~ 00085z 100:a2
{,~~ oxL~E '. _.. 0 002292682
~-Rl(~K-yn~JE~] 313.Gi~ 90 1 (/ZCN7RKikIpF oO09824476.
? amalCLr~a vi y[~1~ Fr,:] 0 0 7 5 ~ okl ^CI t' lL rcs - xJEe 0.00072 sai y( .
. p"mx',a"r-,-.[IF 000 D00
Ji6+;CO [NS, t ... 3.2892E+'2i 5Y I,~LI~MOKICE 0.000% 6Z3
,r ]ll'..:.-.. I =.IDt 002248. 26356
f(~J!3fV ~fA3,l-A~] ... 0.915 M4~CN1A . _ 0,00037 .. . 4.34
FeC Lr ~ G'~G ~o-a cr~ cr11onL1- P.oooa~. 3tD5
( fy~~.~yy7 c;r?ECn: 'Anr:Dr .. .. 0 a0039 462
_.~._ . u
M . ~t;~r=:E O oU.
WR HR 0.87201 475b2 0 .00
ET,,,,Q*~ Om o.m
CAF 10J DIOk1Dt 0.10397 56.71 E r~>_ ooa r,m
PF IP"I^,E O.OU ODO
l./~L' a~J 4~x)DE , . . 0.00505. 2:76 rrvkuJTRtf , . ... 000'. OAO
41FD O .~383 4492
0)fL~ad 0.00227 1_24 _ Sk.tV,w- 1;~WI0..,.
HYIFS~C`rh 0.00108 0.59 W;'E o.a9~~s e s7~
Cp7B"74
GIUwGE 0.24939 3.OSR
rRC,CTV 0.D011 0b0 "ParJ+k a r;:rGe ; o.o20660253
J[Tk~~C~TJ 0 00059 0.32 ~~ "L' o Oo7x a.c~av
, .. .... . HVLJRCK~N . ... 000? QA37
ctar,~F~~oal` 000 0,00 AF,`s' o.00361 oow
. ~J:r2R7~J = CtCU229 OD28gAL MIPlJP!Oxi~ 0.00181 0:~ 000. o.am
FL~l' f 1011DE 0AQ086 0,48 ~ n lrx , a,. ,~ o.m19s on24
DdJJB
EXAMPLE 2: The following graph is a simulation of the system pressure impact
on the
performance of the process described in Fig. 2. The variable is the system
pressure. The heated
process water 9 is at a temperature of 90C. The graph is for the combustion of
1000kg/hour of
petcoke as fuel in air. The pressure is in bar. The conclusion drawn from the
simulation graph is
that the optimal pressure for that particular system is in the range of 10bar.
Beyond that , the
pressure of the recovery efficiency increases slightly, but the facility TIC
(Total Installed Cost)
and operation costs will increase dramatically due to the high pressure.
-35-
CA 02665747 2009-05-12
................................ . . . ................. . . . . . . . . . . .
. . . . . ................ . . . . . ............... .................
......................................... . . . . . .......... . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
90C Water Yield vs. P
12000a ..;_...... .
zooooc _;._........_. .................. .............. ....................
.:.................................... _._................. ._
................................ ...........................
........_._........... ..
aoooe
. ............ . ..............._
GOOOC
40000
2000C .... .... ..... ............ .. . .............. .............. .......
.........
e
0 10 20 30 40 50 60 .
EXAMPLE 3: The following results show the simulation of a hot water generation
system, as
described in figure 12. The system pressure is 10bar. The simulation balance
was done for 1
ton/hour of petcoke. Flow S-1 on the spreadsheet is stream 43 on figure 12 and
it is MFT with
23% solid concentration. Flow S-3 is flow 48 on figure 12 and it is petcoke
fuel. Flow S-2 is
flow 49 on figure 12 and it is the combustion gas (air). Flow S-6 is flow 47
on figure 12 and it is
the discharged gas and steam stream from the DCSG. The discharged gas during
the simulation
was about 300C. The discharged gas temperature could change the amount of MFT
converted to
hot water and solid waste per each ton of fuel (or per each ton of generated
hot process water).
Reducing the DCSG discharged gas temperature will increase the amount of MFT
43 consumed
by the DCSG. Stream S-7 is stream 51 on figure 12. 90% of the MFT solids are
removed through
S-7 where the rest carry on to S-6. It is expected that the discharged solids
will include some
water, however, to simplify the simulation it is assumed that all the water
evaporates. Stream S-
8 is the cold process water supplied from the tailing pond 41. It is assumed
that the tailing pond
recycled water is at 20C. Stream S-10 is the generated hot process water. The
heated process
-36-
CA 02665747 2009-05-12
water temperature is 90C.
The bottom-line is that the simulation results show that for each one ton/hour
of combusted
petcoke, about 100ton/hour of 90C heated process water is generated. About
12ton/hour of MFT
are converted to process hot water and dry solids. This does not include the
additional MFT that
can be removed by mixing the generated "water starving" dry solids from the
DCSG with
additional MFT or even with dewatered centrifuge MFT "cake".
s-1 5-3
(thtATEfl) S-2 (ARC) (FUEL) S5S-6 S-7 5-8 S-10
T,C 20.00 25.00 25.00 299.73 299.73 29933 20.00 89.98 Enthalpy.MlJh 165005.00 -
97.30 0.00 165103.70 152754,60 -12349.13 1467370.00 1580274.00
Mass Flowrate, kg/h 12311.00 12527.84 1000A0 25838.84 23281.94 2556,90
92300.00 101463.90
H20 4470.00 0.00 0.00 947000 9470.00 0.00 92300.00 101179.80
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