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Patent 2739420 Summary

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(12) Patent: (11) CA 2739420
(54) English Title: SYSTEMS AND METHODS FOR GENERATING ELECTRICITY FROM CARBONACEOUS MATERIAL WITH SUBSTANTIALLY NO CARBON DIOXIDE EMISSIONS
(54) French Title: SYSTEMES ET PROCEDES DE PRODUCTION D'ELECTRICITE A PARTIR DE MATIERE CARBONEE AVEC SUBSTANTIELLEMENT PEU D'EMISSIONS DE DIOXYDE DE CARBONE
Status: Deemed expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • F01K 13/00 (2006.01)
  • F01K 23/06 (2006.01)
  • F02C 3/28 (2006.01)
(72) Inventors :
  • ZUBRIN, ROBERT M. (United States of America)
  • BERGGREN, MARK H. (United States of America)
(73) Owners :
  • PIONEER ENERGY, INC. (United States of America)
(71) Applicants :
  • PIONEER ENERGY, INC. (United States of America)
(74) Agent: RICHES, MCKENZIE & HERBERT LLP
(74) Associate agent:
(45) Issued: 2013-02-05
(22) Filed Date: 2011-05-09
(41) Open to Public Inspection: 2011-09-20
Examination requested: 2011-07-15
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data: None

Abstracts

English Abstract

Disclosed herein is a system and method for generating"clean" electricity from carbonaceous material, and producing high-pressure CO2 which can be easily sequestered or utilized for a beneficial purpose, such as fuel production. This system and method utilizes a reformation process thatreforms carbonaceous fuel with superheated steam into a high-pressure gaseous mixture that is rich in carbon dioxide and hydrogen gas. This high-pressure gas exchanges excess heat with the incoming steam from a boiler. Once cooled, the high-pressure gas goes through a CO2separator,after which the CO2-rich gas is sequestered underground or beneficially re-used. The remaining hydrogen-rich gas is used to generate power in a power generation subsystem, such as a gas turbine or a fuel cell. Therefore, carbon-free power is produced from coal, biomass, natural gas, or another carbon-based feedstock.


French Abstract

Système et procédé de production d'électricité « propre » à partir de matière carbonée, et de production de dioxyde de carbone à pression élevée qui peut être facilement séquestré ou utilisé de façon avantageuse, par exemple pour la production de carburant. Ce système et procédé utilise un processus de reformation qui reforme le carburant carboné grâce à la vapeur surchauffée en mélange gazeux à pression élevée riche en dioxyde de carbone et en hydrogène gazeux. Ce gaz à pression élevée échange la chaleur excédentaire avec la vapeur qui provient d'une chaudière. Une fois refroidi, le gaz à pression élevée passe à travers un séparateur de dioxyde de carbone, après quoi le gaz riche en dioxyde de carbone est séquestré sous la terre ou réutilisé avantageusement. Le gaz riche en hydrogène qui reste est utilisé pour générer de l'énergie dans un sous-système de génération d'énergie, comme une turbine à gaz ou une pile à combustible. Donc, de l'énergie est produite sans émission de carbone, à partir de charbon, de biomasse, de gaz naturel ou d'autre source carbonée.

Claims

Note: Claims are shown in the official language in which they were submitted.



CLAIMS
What is claimed is:

1. An apparatus for generating electricity from carbonaceous material having
substantially low carbon dioxide emissions, comprising:

a boiler to boil water to generate steam;

a steam reformer to react the carbonaceous material with the steam at high-
pressure
in an absence of air to generate a high-pressure gas comprising primarily
carbon dioxide
gas and hydrogen gas, wherein sufficient water is provided to ensure a
substantial majority
of the carbonaceous material is converted into carbon dioxide gas and hydrogen
gas;

a heat exchanger after the steam reformer to exchange heat from hot gas
exiting the
steam reformer to boil water into the steam;

a CO2 separator to separate at high pressure at least a portion of the carbon
dioxide
gas from the high-pressure gas to generate a carbon dioxide-rich gas and a
hydrogen-rich
fuel gas; and

a gas turbine to utilize a portion of the hydrogen-rich fuel gas to generate
electricity,
wherein waste heat from the gas turbine is used to provide heat needed to boil
water in the
boiler, and

wherein the carbon dioxide-rich gas is utilized in an industrial process,
thereby
generating electricity with substantially low carbon dioxide emissions.

2. The apparatus of claim 1, wherein the carbonaceous material is selected
from the
group consisting of coal, biomass, natural gas, crude petroleum, ethanol,
methanol, and
trash.

3. The apparatus of claim 1, wherein the substantially low carbon dioxide
emissions are
selected at a level that is substantially less than carbon dioxide emissions
associated with
electricity generated from combustion of natural gas.

4. The apparatus of claim 1, wherein an amount of carbon dioxide released in
the
industrial process is less than an amount of carbon dioxide utilized in the
industrial process.
28


5. The apparatus of claim 1, wherein the high-pressure gas further comprises
residual
carbon monoxide, and wherein the apparatus further comprises:

a water gas-shift reactor disposed downstream of the steam reformer for
converting
the residual carbon monoxide into additional carbon dioxide gas and additional
hydrogen
gas.

6. The apparatus of claim 1, wherein the high-pressure gas further comprises
residual
carbon monoxide, and wherein the apparatus further comprises:

a methanation reactor disposed downstream of the steam reformer for converting
the
residual carbon monoxide into methane.

7. The apparatus of claim 1, further comprising:

a furnace to utilize a portion of the hydrogen-rich fuel gas to generate heat
necessary
to drive the steam reformer.

8. The apparatus of claim 7, further comprising:

a second heat exchanger disposed between the boiler and the furnace to
exchange
heat between the hot gas exiting the furnace and the steam generated by the
boiler.

9. The apparatus of claim 1, further comprising:

a condenser disposed after the heat exchanger to condense and cool high-
pressure gas
before entering the CO2 separator.

10. The apparatus of claim 1, further comprising:

a compressor to compress the carbon dioxide-rich gas to a pressure appropriate
for
injection into a petroleum reservoir to extract hydrocarbons.

29


11. The apparatus of claim 1, wherein the steam reformer operates at a
pressure of
approximately 5 bar to 100 bar.

12. The apparatus of claim 1, wherein the CO2 separator is a methanol-based
separator.
13. The apparatus of claim 12, wherein the methanol-based separator operates
in a
temperature-swing cycle between approximately -60° C and +40° C.

14. The apparatus of claim 1, further comprising:

a control system to control an operation of the apparatus based on a market
price of
the carbonaceous material, a market price of electricity, and a market price
of a product of
the industrial process.

15. The apparatus of claim 1, wherein the steam reformer is selected from the
group
consisting of a fixed bed reformer, a fluidized bed reformer, and an entrained-
flow
reformer.

16. The apparatus of claim 1, wherein the industrial process is fuel
production.

17. The apparatus of claim 1, wherein the industrial process is selected from
the group
consisting of growing algae and growing plants in greenhouses.

18. The apparatus of claim 1, wherein the industrial process is carbon
sequestration in a
location selected from the group consisting of saline aquifer, depleted oil
field, depleted gas
field, unmineable coal seam, and the ocean.

19. The apparatus of claim 1, wherein the industrial process is enhanced oil
recovery
(EOR).



20. The apparatus of claim 1, wherein the industrial process is enhanced gas
recovery.
21. A method for generating power from carbonaceous material, comprising:

boiling water into steam;

reforming the carbonaceous material with the steam to generate a high-pressure
gas
comprising carbon dioxide gas and hydrogen gas, wherein sufficient steam is
provided to
ensure a substantial majority of the carbonaceous material is converted into
carbon dioxide
gas and hydrogen gas;

exchanging heat from hot gas exiting the reforming step with the steam
entering the
reforming step;

separating at least a portion of the carbon dioxide gas from the high-pressure
gas to
generate a carbon dioxide-rich gas and a hydrogen-rich gas;

utilizing the carbon dioxide-rich gas in an industrial process; and

generating power in a power generation system from a portion of the hydrogen-
rich
gas.

22. The method of claim 21, wherein the carbonaceous material is selected from
the
group consisting of coal, biomass, natural gas, crude petroleum, ethanol,
methanol, and
trash.

23. The method of claim 21, wherein the power generated effects the output of
carbon
dioxide emissions at a level substantially less than carbon dioxide emissions
associated
with power generated from combustion of natural gas.

24. The method of claim 21, wherein an amount of carbon dioxide released in
the
industrial process is less than an amount of carbon dioxide utilized in the
industrial process.
31


25. The method of claim 21, wherein the high-pressure gas further comprises
residual
carbon monoxide, and wherein the method further comprises:

water-gas-shifting the residual carbon monoxide into additional carbon dioxide
gas
and additional hydrogen gas.

26. The method of claim 21, wherein the high-pressure gas further comprises
residual
carbon monoxide, and wherein the method further comprises:

converting the residual carbon monoxide into methane.
27. The method of claim 21, further comprising:

utilizing a portion of the hydrogen-rich gas to generate heat necessary to
drive the
steam reformer.

28. The apparatus of claim 21, further comprising:

condensing the high-pressure gas after the reforming step and before the
separating
step.

29. The method of claim 21, further comprising:

compressing the carbon dioxide-rich gas to a pressure appropriate for
injection into a
petroleum reservoir to extract hydrocarbons.

30. The method of claim 21, wherein the reforming step is performed at a
pressure of
approximately 5 bar to 100 bar.

31. The method of claim 21, wherein the separating step utilizes a methanol-
based
separation method.

32


32. The method of claim 31, wherein the methanol-based separation method
operates in a
temperature-swing cycle between approximately -60°C and +40°C.

33. The method of claim 21, further comprising:

controlling the method based on a market price of the carbonaceous material, a

market price of electricity, and a market price of a product of the industrial
process.

34. The method of claim 21, wherein the reforming step utilizes a reformer
selected from
the group consisting of a fixed bed reformer, a fluidized bed reformer, and an
entrained-
flow reformer.

35. The method of claim 21, wherein the industrial process is fuel production.

36. The method of claim 21, wherein the industrial process is selected from
the group
consisting of growing algae and growing plants in greenhouses.

37. The method of claim 21, wherein the industrial process is carbon
sequestration in a
location selected from the group consisting of saline aquifer, depleted oil
field, depleted gas
field, and unmineable coal seam.

38. The method of claim 21, further comprising:

supplying oxidizing agent during the reforming step to create autothermal
reforming
conditions.

39. The method of claim 21, wherein the power generation system is a gas
turbine.
40. The method of claim 21, wherein the power generation system is a fuel
cell.
33

Description

Note: Descriptions are shown in the official language in which they were submitted.



CA 02739420 2011-07-15

SYSTEMS AND METHODS FOR GENERATING ELECTRICITY FROM CARBONACEOUS
MATERIAL WITH SUBSTANTIALLY NO CARBON DIOXIDE EMISSIONS
REFERENCE TO RELATED APPLICATIONS/PATENTS

[1] This application is related to U.S. Patent No. 7,937,948 entitled "SYSTEMS
AND METHODS
FOR GENERATING ELECTRICITY FROM CARBONACEOUS MATERIAL WITH
SUBSTANTIALLY NO CARBON DIOXIDE EMISSIONS" issued on May 10, 2011.

FIELD OF THE INVENTION

[2] This invention relates to a system and method for generating "green
electricity" having
substantially zero or very low CO2 emissions from a carbonaceous
feedstock. One embodiment of
the present invention is a power plant which utilizes a steam reforming
process that may be used to
generate electricity, hydrogen, and high pressure carbon dioxide-rich gas,
which may be either
sequestered or utilized for a beneficial purpose (such as fuel production).

BACKGROUND OF THE INVENTION

[3] The world's power demands are expected to rise 60% by 2030. With the
worldwide total of
active coal plants over 50,000 and rising, the International Energy Agency
(IEA) estimates that fossil
fuels will account for 85% of the energy market by 2030.

[4] World organizations and international agencies like the IEA are concerned
about the
environmental impact of burning fossil fuels, and coal in particular.
Electricity generation using carbon-
based fuels is responsible for a large fraction of carbon dioxide (CO2)
emissions worldwide; and for
41% of U.S. man-made carbon dioxide emissions.

[5] Increased concentration of carbon dioxide in the atmosphere assist climate
change including
global warming; concern over the rate of climate change has led to targets to
stabilize or reduce carbon
dioxide and other greenhouse gas (GHG) emissions by between 25 and 40% by
2020. Fossil fueled,
especially coal-fired, plants make reductions difficult. Emissions may be
reduced through more efficient
and higher combustion temperature and through more efficient production of
electricity within the cycle.
Carbon capture and storage (CCS) of emissions from coal-fired power stations
is another alternative but
the technology is still being developed and will increase the cost of fossil
fuel-based production of
electricity using existing technologies. Existing CCS technologies may not be
economically viable,
unless the price of emitting CO2 to the atmosphere rises. (Portions cited
from Wikipedia.org).
1


CA 02739420 2011-05-09

]6] The inventors have recognized a unique solution to the above mentioned
issues as well other problems and
difficulties associated withcarbon capture from prior art power plants.
Accordingly, the inventors have devised the
present invention which allows generating clean electric power from
carbonaceous material such as coal, biomass,
natural gas, etc.

]7] It is against this background that various embodiments of the present
invention were developed.
BRIEF SUMMARY OF THE INVENTION

18] Accordingly, another embodiment of the present invention is a method for
generating power from
carbonaceous material, including the following steps: (1) boiling water into
steam; (2) reforming the carbonaceous
material with the steam to generate a high-pressure gas comprising carbon
dioxide gas and hydrogen gas, wherein
sufficient steam is provided to ensure a substantial majority of the
carbonaceous material is converted into carbon
dioxide gas and hydrogen gas; (3) exchanging heat from hot gas exiting the
reforming step with the steam entering
the reforming step; (4) separating at least a portion of the carbon dioxide
gas from the high-pressure gas to generate
a carbon dioxide-rich gas and a hydrogen-rich gas; (5) utilizing the carbon
dioxide-rich gas in an industrial process;
and (5) generating power in a power generation system from a portion of the
hydrogen-rich gas.

]9] Another embodiment of the present invention is the method described above,
wherein the carbonaceous
material is coal, biomass, natural gas, crude petroleum, ethanol, methanol,
trash, and/or mixtures thereof.

]10] Another embodiment of the present invention is the method described
above, wherein the power generated
has substantially less associated carbon dioxide emissions than power
generated from combustion of natural gas.
]11] Another embodiment of the present invention is the method described
above,wherein an amount of carbon
dioxide released in the industrial process is less than an amount of carbon
dioxide utilized in the industrial process.
]12] Another embodiment of the present invention is the method described
above, wherein the high-pressure gas
further comprises residual carbon monoxide, and also including the step of
water-gas-shifting the residual carbon
monoxide into additional carbon dioxide gas and additional hydrogen gas.

]13] Another embodiment of the present invention is the method described
above,wherein the high-pressure gas
further comprises residual carbon monoxide, and also including the step of
converting the residual carbon monoxide
into methane.

]14] Another embodiment of the present invention is the method described
above, also including the step of
utilizing a portion of the hydrogen-rich gas to generate heat necessary to
drive the steam reformer.

2


CA 02739420 2011-05-09

]15] Another embodiment of the present invention is the method described
above, also including the step of
condensing the high-pressure gas after the reforming step and before the
separating step.

[16] Another embodiment of the present invention is the method described
above, also including the step of
compressing the carbon dioxide-rich gas to a pressure appropriate for
injection into a petroleum reservoir to extract
hydrocarbons.

[17] Another embodiment of the present invention is the method described
above,wherein the reforming step is
performed at a pressure of approximately 5 bar to 100 bar.

[18] Another embodiment of the present invention is the method described
above,wherein the separating step
utilizes a methanol-based separation method. Another embodiment of the present
invention is the method described
above, wherein the methanol-based separation method operates in a temperature-
swing cycle between approximately
-60o C and +40o C.

[19] Another embodiment of the present invention is the method described
above, also including the step of
controlling the method based on a market price of the carbonaceous material, a
market price of electricity, and a
market price of a product of the industrial process.

[20] Another embodiment of the present invention is the method described
above,wherein the reforming step
utilizes a reformer selected from the group consisting of a fixed bed
reformer, a fluidized bed reformer, and an
entrained-flow reformer.

1211 Another embodiment of the present invention is the method described
above, wherein the industrial process
is fuel production.

[22] Another embodiment of the present invention is the method described
above,wherein the industrial process
is growing algae or growing plants in greenhouses.

[23] Another embodiment of the present invention is the method described
above, wherein the industrial process
is carbon sequestration in a saline aquifer, depleted oil field, depleted gas
field, orunmineable coal seam.

[24] Another embodiment of the present invention is the method described
above, also including the step of
supplying oxidizing agent during the reforming step to create autothermal
reforming conditions.

[25] Another embodiment of the present invention is the method described
above,wherein the power generation
system is a gas turbine.

[26] Another embodiment of the present invention is the method described
above,wherein the power generation
system is a fuel cell.

3


CA 02739420 2011-05-09

1271 Yet another embodiment of the present invention is a power plant for
generating electricity having
substantially low carbon dioxide emissions, made up of the following
components: A boiler is used to generate
steam from water. A steam reformer is used to react a carbonaceous material
with steam at high-pressure in an
absence of air to generate a high-pressure gas comprising primarily carbon
dioxide and hydrogen gas, where
sufficient water is provided to ensure a substantial majority of the
carbonaceous material is converted into carbon
dioxide and hydrogen.A CO2 separator is used to separate at high-pressure at
least a portion of the carbon dioxide
gas from the rest of the high-pressure gas to generate a carbon dioxide-rich
gas and also a hydrogen-rich fuel gas.
1281 The hydrogen-rich fuel gas is used to generate electricity using, for
example, a gas turbine or fuel cell.
Waste heat from the gas turbine or fuel cell may be used to provide heat
needed to boil water in the boiler.The high
pressure carbon dioxide gas is then sequestered or utilized in an industrial
process, thereby generating electricity
with substantially low carbon dioxide emissions.

1291 Yet another embodiment of the present invention is the apparatus
described above where the carbonaceous
material is coal, biomass, natural gas, crude petroleum, ethanol, methanol,
and/or trash, and/or mixtures thereof.

[301 Yet another embodiment of the present invention is the apparatus
described above, where the electricity
generated has substantially less associated carbon dioxide emissions than
electricity generated from combustion of
natural gas.Yet another embodiment of the present invention is the apparatus
described above, where an amount of
carbon dioxide released in the industrial process is less than an amount of
carbon dioxide sequestered or utilized in
the industrial process.

1311 Yet another embodiment of the present invention is the apparatus
described above, where the high pressure
gas also includes carbon monoxide, and where the apparatus also includes a
water-gas shift reactor disposed
downstream of the steam reformer for converting residual carbon monoxide into
additional carbon dioxide and
additional hydrogen.

[321 Yet another embodiment of the present invention is the apparatus
described above, also including a
methanation reactor disposed downstream of the steam reformer for converting
residual carbon monoxide into
methane.

1331 Yet another embodiment of the present invention is the apparatus
described above, also including a furnace
adapted to utilize a portion of the hydrogen-rich fuel gas to generate heat to
drive the steam reformer.

[341 Yet another embodiment of the present invention is the apparatus
described above, also including a heat
exchanger disposed between the boiler and the steam reformer adapted to
exchange heat between the hot high-
pressure gas exiting the steam reformer and the steam entering the steam
reformer from the boiler.Yet another
embodiment of the present invention is the apparatus described above, also
including a heat exchanger disposed
between the boiler and the furnace adapted to exchange heat between the hot
gas exiting the furnace and the steam
being heated by the boiler.
4


CA 02739420 2011-05-09

1351 Yet another embodiment of the present invention is the apparatus
described above, also including a
condenser disposed after the heat exchanger adapted to cool high-pressure gas
entering the CO2 separator from the
heat exchanger.

[361 Yet another embodiment of the present invention is the apparatus
described above, also including a
compressor adapted to compress the carbon dioxide-rich gas to a pressure
appropriate for injection into a petroleum
reservoir to extract oil or natural gas.

1371 Yet another embodiment of the present invention is the apparatus
described above, where thesteam
reformer operates at a pressure of approximately 5 bar to 100 bar.

1381 Yet another embodiment of the present invention is the apparatus
described above, where the CO, separator
is a methanol-based separator.Yet another embodiment of the present invention
is the apparatus described above,
where the methanol-based separator operates in a temperature-swing cycle
between approximately -60 C and +40
C.

1391 Yet another embodiment of the present invention is the apparatus
described above, also including a control
system adapted to control an operation of the apparatus based on a market
price of the carbonaceous material, a
market price of electricity, and a market price of a product of the industrial
process.

1401 Yet another embodiment of the present invention is the apparatus
described above, where the steam
reformer is a fixed bed reformer, a fluidized bed reformer, or an entrained-
flow reformer.

[411 Yet another embodiment of the present invention is the apparatus
described above, where the industrial
process is fuel production.

1421 Yet another embodiment of the present invention is the apparatus
described above, where the industrial
process is growing algae or growing plants in greenhouses.

1431 Yet another embodiment of the present invention is the apparatus
described above, where the industrial
process is carbon sequestration in a saline aquifer, depleted oil field,
depleted gas field, unmineable coal seam, or
ocean sequestration.

1441 Yet another embodiment of the present invention is the apparatus
described above,where the boiler operates
at a temperature of approximately 150 C to 250 C.

1451 Yet another embodiment of the present invention is the apparatus
described above, where the steam
reformer operates at a temperature of approximately 600 C to 1000 C.



CA 02739420 2011-05-09

]46] Yet another embodiment of the present invention is the apparatus
described above, where the hydrogen-rich
fuel gas further comprises methane.Yet another embodiment of the present
invention is the apparatus described
above, where the hydrogen-rich fuel gas further comprises carbon monoxide.

147] Yet another embodiment of the present invention is the apparatus
described above,where the carbon
dioxide-rich driver gas is at least 70% CO2 by weight.More preferred
embodiments include the apparatus described
above, where the carbon dioxide-rich driver gas is at least 90% CO2 by weight,
and even more preferably at least
97% CO2 by weight.

1481 Finally, another embodiment of the present invention is a method for
generating electricity from
carbonaceous material having low carbon emissions.A quantity of carbonaceous
material is steam reformed at high
pressure with water in an absence of air to generate high pressure gas
comprising a mixture of hydrogen gas and
carbon dioxide gas, where sufficient water is provided to ensure a substantial
majority of the carbonaceous material
is converted into carbon dioxideand hydrogen. The high pressure gas is
separated using a high-pressure CO2
separation process into a carbon dioxide-rich gas and a hydrogen-rich fuel
gas. The carbon dioxide gas stream is
sequestered or utilized in an industrial process,while electric power is
generated using a portion of the separated
hydrogen-rich fuel gas. Therefore, since the CO2 is either sequestered or
beneficially utilized, the electric power is
generated with little or no carbon dioxide emissions into the atmosphere.

1491 Other features, utilities and advantages of the various embodiments of
the invention will be apparent from
the following more particular description of embodiments of the invention as
illustrated in the accompanying
drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

]50] Figure 1 illustrates an example of an embodiment of a power plant
according to the present invention for
the reformation of super-heated high-pressure steam with carbonaceous material
to create a gaseous mixture rich in
hydrogen and carbon dioxide gas in which the hydrogen combusts in a gas
turbine for electricity generation while
the carbon dioxide gas remains stored using sequestration and/or beneficial
use;

1511 Figure 2 illustrates an example of operations for reforming super-heated
steam and carbonaceous material
to create a gas mixture rich in hydrogen and carbon dioxide in which the
hydrogen combusts in a gas turbine for
electricity generation while the carbon dioxide gas remains stored for
sequestration and/or beneficial use;

1521 Figure 3 illustrates an example of an indirect fuel reformer for use with
a power plant of the present
invention, in accordance with a preferred embodiment of the present invention;

]53] Figure 4 illustrates an example of an autothermal fuel reformer in
accordance with an alternative
embodiment of the present invention;

6


CA 02739420 2011-05-09

1541 Figure 5 illustrates an example of a fixed-bed steam reformer for use
with a power plant of the present
invention in accordance with one embodiment of the present invention;

1551 Figure 6 illustrates an example of a fluidized-bed steam reformer foruse
with a power plant of the present
invention in accordance with an alternative embodiment of the present
invention;

1561 Figure 7 illustrates an example of a modular power plant according to yet
another embodiment using the
principles of the present invention; and

1571 Figure 8illustrates yet another example of a power plant of the present
invention using biomass as the
carbonaceous material in accordance with yet another alternative embodiment of
the present invention.

DETAILED DESCRIPTION OF THE INVENTION

1581 Thisinnovative plant design utilizes efficient reformation of
carbonaceous fuel and steam to improveupon
traditional combustion methods of fuel and airwhich currently dominate the
power generation industry. The
reformation of carbonaceous fuel allows power plants to contribute to the
hydrogen economy by producing
hydrogen for less energy than it takes to create it. This design also allows
for sequestration and/or beneficial use of
CO2 for a variety of applications such as the recovery of otherwise
inaccessible oil, fire extinguishers, welding,
pneumatic systems, biological applications, and chemical processing,.

1591 The hydrogen is either burned to produce clean electricity, to be sold to
utilities or used for other uses such
as a chemical production, fuel cell application, or enhanced oil
recovery,depending on which of these methods
produce higher monetary value to the operator.

1601 If biomass is used as the fuel source,as a result of the fact that the
CO2 injected into the ground comes from
biomass, whose carbon came from the atmosphere, the electricity generation
process of the power plant design not
only produces power without emission of CO2 into the environment, in some
embodiments it may actuallyreduce
atmospheric CO,. In fact, in one embodiment, the amount of carbon sequestered
in the process may be on average
about 5-30%, and preferably 20-30%, greater than the amount of carbon in the
oil recovered. Thus, not only the
electricity, but even the oil produced by the enhanced oil recoveryprocess can
be said to be truly "green," since it
has been fully paid for by the carbon sequestered to get it.

1611 Throughout this disclosure, the symbol "kcf' shall stand for "thousand
standard cubic feet," usually of CO2
unless explicitly stated otherwise. The symbol "MMcf' shall stand for "million
standard cubic feet," usually of CO2
unless explicitly stated otherwise. That is, a reformer that produces I
kcf/day of driver gas produces 1,000 standard
cubic feet of driver gas per day, while a reformer that produces I MMcf/day of
driver gas produces 1,000,000
standard cubic feet of driver gas per day. The word "day" shall mean "a day of
operations," which could be an 8-
hour day, a 12-hour day, a 24-hour day, or some other amount of time. Please
note that other sources may use
7


CA 02739420 2011-05-09

different symbols, such as "mcf ' for "thousand cubic feet" based on the Roman
numeral "M" for thousand, and care
should be taken in terminology when consulting such sources.

STEAM REFORMING OF BIOMASS AND H, USED TO GENERATE ELECTRICITY

1621 One of many illustrative scenarios is presented here to demonstrate the
potential profitability of the
reformation power plant design. In this scenario, biomass is used as the
carbonaceous material feedstock;the CO2
produced is used for EOR, while all of the hydrogen is used for power
generation.

[63] Steam reformation of biomass occurs approximately in accord with the
following reaction:
C4H6O3 + 5H,O => 4CO, + 8H, AH= +118 kcal/mole (1)

[64] If two of the hydrogen molecules are burned to provide process heat, 114
kcal of energy can be released.
So the burning of two moles of hydrogen can drive I unit of reactions (1) for
a net reaction of

C4H6O3 + 3H2O + 02 => 4CO, + 6H, AH= +4 kcal/mole (2)

[65] Reaction (2) is essentially energy neutral. While the oxygen used in
reaction (2) could be injected directly
into the steam reformation reactor, this would either require expensive oxygen
separation technology, or
compressing air into the -10 bar steam reformation system, which involves high
energy costs and also dilutes the
CO2 product with large amounts of nitrogen. Such nitrogen diluent makes
subsequent CO2 separation difficult for
sequestration, and so if underground CO2 sequestration is desired, such
autothermal approaches are
disadvantageous. Therefore, in the preferred reformation system, reaction (1)
is driven by an external gas-fired
furnace deriving its energy from hydrogen combustion which is fueled by
utilizing 1/4'h of the hydrogen produced
by reaction (1).

[66] Compared to air or oxygen blow gasification, the reformation system
design offers the critical advantages
that it yields a high pressure gas mixture that is 1/3 CO2 by mole, with no
nitrogen present, and no need to separate
oxygen or compress air. Indeed, the only compression work required to feed a
high pressure steam reformation
system is the very small amount needed to bring liquid water up to an elevated
pressure prior to boiling. Such high
pressure, high concentration CO2 is much easier to separate from the other
exhaust gases than the low pressure, low
concentration CO2 present in gasifier or conventional combustion flue gas
exhaust, and thus, if a system is to be
designed for the primary purpose of securing CO2 for sequestration, this is
the preferred system design option.

[67] If the steam reformation is carried out completely in accord with
reaction (1), it will produce a gas mixture
that is 33% CO_ This concentration can be reduced somewhat by reverse water-
gas-shift side reactions that may
occur, i.e.:

CO2 + H2 => CO + H2O AH = +9 kcal/mole (3)
8


CA 02739420 2011-05-09
1681 Or increased as a result of methanation side reactions:

CO2 + 4H, => CH4 + 2H7O AH = -41 kcal/mole (4)

1691 However, on net, a CO2 concentration (in the gas after water knockout)
over 30% can be achieved. This
CO2 concentration is much higher than that available in combustion flue gas,
and is very favorable for CO2
separation.

1701 Reaction (3) is undesirable, but it has a low equilibrium constant (-0.1
at 400 C) and can be nearly entirely
suppressed by running the system steam rich. Reaction (4) is a mixed blessing
and curse. While it removes COZ, it
actually increases the fraction of CO2 in the exhaust (by removing 4 hydrogen
molecules for every one CO7 that is
removed), making efficient separation easier. The methane it produces also
adds to the volumetric energy content of
the hydrogen-rich fuel, which enhances electricity production. Furthermore,
since reaction (4) is exothermic, it can
substantially reduce further the amount of hydrogen that needs to be burned in
the furnace to help drive reaction (1).
While it has a high equilibrium constant (_106), it can be mostly suppressed
in favor of reaction (1) by running the
system steam rich. Assuming, however, that one in four CO2 molecules produced
by reaction (1) is consumed by
reaction (4), and we use the extra energy to cut the hydrogen furnace fuel
requirement, we obtain a net reaction:

C4H6O3 + 2H,O + 1/20, _> 3CO2 + CH4 + 3H, AH= +18 kcal/mole (5)

1711 Reaction (5) is endothermic, but only to a mild degree, so it can be
driven forward by superheating the
input steam in the furnace.

1721 The part of reaction (5) occurring in the steam reformer alone is:

C4H6O3 + 3H2O => 3CO2 + CH4 + 4H2 AH= +75 kcal/mole (6)
1731 It will be observed that the CO2 fraction of the steam reformer exhaust
gas has risen to 43%.

1741 Reaction (6) is best done at moderate to high pressure, with 10 bar being
adequate to get good results. Since
the only gas that needs to be fed to the system is steam, which is derived
from water which is initially pressured in
the liquid phase, the required compression energy is minimal. Running reaction
(6) at high pressure also has the
advantage of producing high pressure exhaust gas, which simplifies the task of
separating the CO2 from the other
product gases. In addition, the presence of moderate to high-pressure high-
temperature steam in the reactor acts to
suppress coking and to destroy tars and oils emitted from the carbonaceous
fuel.

1751 Let us consider the economics of a reformer power plantnear an oil field.
Depending on the field, it takes
between 5,000 and 10,000 cubic feet of CO2 to produce I barrel of oil. We
adopt the more conservative number of
10,000 cubic feet/bbl. In that case, it will take 560 metric tons of CO2 per
day to produce 1,000 barrels per day of
oil. Examining reaction (6), we see-that 3 CO2 molecules with a total
molecular weight of 132 are produced for
9


CA 02739420 2011-05-09

every unit of biomass with a molecular weight of 102, for a wither ratio of
about 1.3. Thus producing 560 metric
tons of CO2 will require 430 tons of biomass. Currently, corn stover can be
obtained for about $40 per ton, delivered
cost, within 50 miles. Thus 430 tons of corn stover would go for a cost of
about $17,200. Other forms of crop or
forestry residues, or even coal, could potentially be obtained much cheaper,
depending upon the locality, but we will
use commercially priced corn stover in our analysis to be conservative. This
would allow the production of 1,000
barrels of oil, which at a price of $60/bbl, would be worth $60,000.

1761 However, in addition to the oil product, the system also produces
electricity. At the same time that 560
metric tons of CO, are produced, it also produces 68 tons of methane and 25.4
tons of hydrogen. If burned in air,
these will produce 2,000 MWt-hours of energy. Assuming 30% efficiency, this
translates into 600 MWe-hours of
power, which at a price of $0.05/kWh, would sell for $30,000. The power output
of the system would be 25 MWe,
which is well within the range of many gas turbine units produced by industry.
It may be further noted that the
revenue from electricity alone significantly exceeds the cost of feedstock
(and other daily costs, outlined below).

1771 Adding the $30,000 per day revenue from electricity to the $60,000 earned
from oil, we see that a total
gross income of $90,000 per day can be obtained at a cost of $17,200 in
feedstock. Assuming labor costs of $8000
per day and capital and depreciation costs of $8,200 per day (assuming a per
unit capital cost of $30 million, paid off
at 10% per year), total daily operating costs would be $33,400. Thus the net
profit of the operation would be
$36,600 per day, or about $13.6 million per year.

1781 Therefore, using the principles taught by the present invention,
profitable hydrogen productionand clean
electricity production may become economically feasible.

PREFERRED SYSTEM BLOCK DIAGRAM

1791 Fig. I shows a block diagram of a preferred embodiment of a reformer
power plant system 100. Water
from water tank 112 is compressed ina pump 113 into boiler 114, where it is
boiled and brought to 200 C. The
steam 115then passes through heat exchanger 116, where heat from exiting
hotgas pre-heats the steam] 15 and cools
the exiting gas, increasing the overall efficiency of the system 101.
Carbonaceous fuel 113 and hot steam115 enter
steam reformer 122, which operates at approximately 850 C and 10 bar. Ash is
collected in ash tray 124, from the
bottom of the steam reformer 122. The heat to drive steam reformer 122 is
provided by furnace 118, which is fueled
by hydrogen gas. Exiting high pressure gas passes through heat exchanger 116,
pre-heating the steam 1l5from
boiler 114. The exiting high pressure gas passes around boiler 114 and water
tank 112, further releasing heat to
these elements. Finally, exiting driver gas 127 is passed through condenser
126, before being fed to methanol CO2
separator 128, the operation of which is described in greater detail below.
The high pressure gas is composed
primarily of carbon dioxide and hydrogen gas, but may also include methane gas
and carbon monoxide gas, as well
as possibly other gases. The methanol CO2 separator 128 produces a CO2 gas
stream 133 comprised essentially of
CO,, and a fuel stream 129 comprised primarily of hydrogen, but also methane,
carbon monoxide, and possibly
other gases. The fuel gas stream 129 is fed into gas turbine 130, as well as
furnace 118. Gas turbine 130 produces


CA 02739420 2011-05-09

electricity 132 via generator 131, which may be used locally or fed to the
grid 132. Furnace 118 burns a portion of
the fuel gas in order to generate the heat necessary to drive the reforming
reaction taking place in the steam reformer
122.

1801 The high-pressure gas may also include residual carbon monoxide, and a
water gas-shift reactor (not shown
in Fig. 1) may be disposed downstream of the steam reformer for converting the
residual carbon monoxide into
additional carbon dioxide gas and additional hydrogen gas. Alternatively, a
methanation reactor (not shown in Fig.
1) may be disposed downstream of the steam reformer for converting the
residual carbon monoxide into methane.
As noted previously, the high-pressure gas may also include residual methane,
which is advantageous, since it
makes it easier to combust the hydrogen gas in the gas turbine.

1811 The boiler 114 may operate at a temperature of approximately 150 C to
250 C.

1821 The steam reformer 122 may operate at a temperature of approximately 600
C to 1000 C, and a pressure
of approximately 5 bar to 100 bar. The steam reformer may be a fixed bed
reformer, a fluidized bed reformer, or an
entrained-flow reformer, or another steam reformer design known in the art.

1831 The methanol CO2 separator 128 may operate in a temperature-swing cycle
between approximately -60 C
and +40 C.

1841 The apparatus may also include a control system adapted to control an
operation of the apparatus based on
a market price of carbonaceous material, a market price of electricity, and a
market price of crude petroleum (as
described in greater detail below).

[85J The carbon dioxide-rich driver gas is preferably at least 70% CO2 by
weight, but more preferable at least
90% CO2 by weight, and even more preferably at least 97% CO2 by weight.

1861 Fig. 2 illustrates an example of operations 200 that may be performed in
order to generate electricity from
carbonaceous material with low CO2 emissions. The process begins at operation
201. At operation 202, a pump
pressurizes water. At operation 203, steam is generated from the pressurized
water, for example, using a boiler. At
operation 204, the carbonaceous material is reformed using steam into high
pressure gas. At operation 205, a
separator separates the high pressure gas into CO2 and H, rich gases. At
operation 206, the carbon dioxide is
sequestered and/or used for beneficial purposes. The rest of the driver gas,
which may include hydrogen gas, as well
as minor amounts of methane, carbon monoxide, as well as other gases, are
combusted in order to generate
electricity and heat, as shown in operation 207. In one example, operation 207
may include combustion of hydrogen
and small amounts of methane, in order to provide energy, for instance, within
a gas turbine. At operation 208, heat
passes through a heat exchanger to help drive the reformation reaction. The
energy generated from the combustion
may be used to heat the feedstock to a temperature where the carbonaceous
material reacts with water to form a
hydrogen and carbon dioxide-rich high pressure gas, as described in operation
204. Note that the energy used to
drive the reforming reaction can also be provided from burning a fuel other
than hydrogen, or biomass, or from a
11


CA 02739420 2011-05-09

non-combustible source, for example, solar energy, nuclear energy, wind
energy, grid electricity, or hydroelectric
power (not shown in Fig. 2). At operation 209, heat from the exiting high
pressuregas exchanges heat with the
boiler. Some of the heat from the combustion reaction is used to help generate
steam in the boiler, as shown in
operation 209. Finally, the electricity may be used locally or transmitted to
the local grid, as shown in operation
210. The process 200 ends in step 211. This process is illustrative of only
one of many embodiments in which the
present invention may be practiced.

1871 Embodiments of the present invention provide various reformer apparatus
subsystems for generating high-
pressure gas. In some embodiments, the apparatus utilizes a biomass reforming
reaction to generate the high
pressure gas and a hydrogen combustion reaction to provide the energy required
to reform biomass and generate the
high-pressure gas. In addition, the apparatus typically includes heat exchange
elements to facilitate heat transfer
from the high temperature gas to incoming reformer and/or combustion fuel. The
transfer of heat facilitates the
reforming reaction and lowers the energy required to complete the driver gas
formation.An illustrative embodiment
is described in relation to Fig. 3 for separate reformer and combustion
reactions, followed by an embodiment
described in relation to Fig. 4 for autothermal reforming and production of
high-pressure gas bya single reaction
chamber.

1881 Although both an indirect (Fig. 3) and an autothermal (Fig. 4) reformer
are shown here for completeness,
the present invention is best practiced with an indirect reformer (Fig. 3),
since in an indirect reformer the high-
pressure gas does not have nitrogen from air mixed with the generated hydrogen
and carbon dioxide, which aids the
separation process (described below).

INDIRECT REFORMER SUBSYSTEM

189J Fig. 3 illustrates an example of a steam reforming apparatus 300 for
generating high pressure gas (shown as
arrow 302), in accordance with one embodiment of the present invention.

1901 In Fig. 3, an embodiment of the reforming subsystemmay include a first
storage container (not shown) for
storing a combustible material, such as coal, biomass, an alcohol, olefin, or
other like material. A second storage
container (not shown) may also be provided for storing the carbonaceous fuel
for the reforming reaction. The water
may be mixed with the carbonaceous fuel in this container to form slurry.
Alternatively, a third container (not
shown) may be used to store water to be reacted with the feedstock in the
reformer chamber.

1911 In one example, a first chamber 304 has an inlet port 316 and an outlet
port 310 and is adapted to provide
for the combustion of the combustible material. In one example, the first
chamber 304 includes an igniter such as a
spark plug 312 or other conventional igniter, and a nozzle 314 coupled with
the inlet port 316 of the first chamber
304. The inlet port 316 of the first chamber 304 may be coupled with the first
storage container (not shown) so that
the contents of the first storage container may be introduced into and
combusted within the first chamber 304. The
first chamber 304 also includes a port 308 for introducing combustion air into
the first chamber 304. The first
12


CA 02739420 2011-05-09

chamber 304 is also adapted to receive a portion of the second chamber 306,
described below, so that the
energy/heat from the combustion of the combustible material from the first
storage container (not shown) within the
first chamber 304 is transferred into a portion of the second chamber 306. The
outlet port 310 of the first chamber
304, in one example, is near the inlet port 320 of the second chamber 306, and
a heat exchanger 318 is used to allow
the combustion exhaust gas to heat the carbonaceous fuel and water entering
the second chamber 306.
Alternatively, the outlet 310 of the first chamber 306 can feed to a heat
exchanger located inside the second chamber
306, which thereby allows the combustion exhaust gases produced in the first
chamber 304 to provide the heat to
drive the reforming reactions in the second chamber 306.

1921 The second chamber 306 has an inlet port (shown as arrow 320) and an
outlet port 302. In one example,
the inlet port 320 is coupled with the second and third storage containers
(not shown) and receives the contents of
the second and third storage containers (not shown).

1931 In one example, the second chamber 306 is positioned within the first
chamber 304, such that the
combustion heat/energy from the first chamber 304 heats the carbonaceous fuel
and water sources contained within
the second chamber 306 to a point where the carbonaceous fuel reforms into a
high-pressure gas which exists out of
the outlet port 302 of the second chamber 306. The first and second chambers
may be fluidly isolated.

1941 In one embodiment, shown in Fig. 3, the reformer feed entering the inlet
port 320 may be a single fluid, for
example carbonaceous fuel-water slurry. In other embodiments, not shown in
Fig. 3, the carbonaceous fuel and
water may be fed into the reformer chamber through separate inlets.

1951 In one example, a first heat exchanger 318 is coupled with the outlet
port 310 of the first chamber 304 (the
combustion chamber) and is thermodynamically coupled with a portion of the
inlet port of the second chamber 306.
In this manner, the hot combustion exhaust gases from the first chamber are
used to preheat the carbonaceous fuel
and water sources as they are being introduced into the second chamber 306 for
reformation into a high-pressure
gas.

1961 A second heat exchanger 326 may also be utilized, wherein the second heat
exchanger 326 is
thermodynamically coupled with the outlet port 302 and the inlet port 320 of
the second chamber 306, which
provides the dual benefit of preheating the carbonaceous fuel and water
sources prior to entry into the second
chamber 306, as well as cooling the driver gas which is expelled from the
outlet port 302 of the second chamber
306.

1971 Notwithstanding the above examples, the present invention does not
require the use of heat exchangers.
The use of heat exchangers is optional. Heat exchangers may be used to
increase the efficiency of the reformer
subsystem. However, there may be situations in which heat exchangers would not
be used, such as when hot gas is
desired and/or when the carbonaceous fuel and water sources are pre-heated by
other means.

13


CA 02739420 2011-05-09
AUTOTHERMAL REFORMER SUBSYSTEM

[98[ Fig. 4 illustrates another example of a steam reformingsubsystem400 for
generating high-pressure gas in
accordance with another embodiment of the present invention. The embodiment
illustrated in Fig. 4 provides an
"autothermal reformer" for the production of high-pressure gas. An autothermal
reformer 400 of the present
invention directly reacts a carbonaceous fuel source with water as well as
oxygen, air, or other oxidizers in a single
chamber 402. Embodiments of the reformer provide an environment for reforming
carbonaceous fuel from a feed at
proper temperature and pressure resulting in the release of high-pressure gas.

[99] Referring to Fig. 4, an autothermal reformer apparatus 400 is shown
having a reaction chamber 402, a
carbonaceous fuel-water slurry delivery pipe (fuel pipe) 404 for delivery of a
mixture of carbonaceous fuel and
water, a driver gas outlet port (outlet port) 406 for release of produced high-
pressure gas 418, and an oxygen or
other oxidizing gas inlet pipe (gas pipe) 408 for delivery of an oxidizing gas
used in the combustion of the
carbonaceous fuel in the reaction chamber.

[100[ Still referring to Fig. 4, the reaction chamber 402 is of sufficient
size and shape for autothermal reforming
of carbonaceous fuel. Different chamber geometries can be used. In the
embodiment shown in Fig. 4, the fuel pipe
404 is coupled to the outlet port 406 to form a counter-exchange heat
exchanger 412 so that the energy/heat from the
exiting driver gas is transferred to the carbonaceous fuel-water slurry
entering the reaction chamber 402 via the fuel
pipe 404. In addition, the fuel pipe 404 typically enters at a first or top
end 414 of the reaction chamber 402 and
releases the fuel toward the second or bottom end 416 of the reaction chamber
402. This configuration enhances heat
released from the heated carbonaceous fuel-water slurry into the contents of
the reaction chamber 402. Release of
fuel into the reaction chamber 402 can be via an outlet 417 or other like
device. The gas pipe 408 is typically
coupled to or adjacent to the fuel pipe 404 and releases the oxygen or other
oxidizing gas adjacent to the release of
the carbonaceous fuel-water slurry 415. When in use, the reaction chamber of
the autothermal reformer apparatus is
typically preheated to a temperature sufficient to start the reforming
reaction, i.e., approximately 500 C, and
preferably above approximately 800 C. Preheating may be accomplished by a
reaction chamber integrated heating
element, a heating coil, an external combustor heating system, an internal
combustion system, or other like device
(not shown).

11011 The carbonaceous fuel and water sources are fed into the reaction
chamber 402 via the fuel pipe 404. At
approximately the same time that the carbonaceous fuel-water slurry is being
delivered to the reaction chamber 402,
the oxygen or other oxidizing agent is being delivered to the reaction chamber
via the inlet pipe 408. Various
reformer chemical reactions are described below.

[102] Once the reforming reaction has been established within the reaction
chamber 402, the reaction-chamber
heating element may be shut off to conserve energy. Note also that the amount
of water combined into the
carbonaceous fuel slurry can be adjusted to control the reforming
temperatures.

14


CA 02739420 2011-05-09

11031 While the example shown in Fig. 4 depicts carbonaceous fuel and water
being fed into the reactor together
in the form of carbonaceous fuel-water slurry, this is illustrative of only
one embodiment. In other embodiments,
shown in Fig. 5 and Fig. 6, carbonaceous fuel and water may be fed into the
reaction chamber through separate
inlets. Also, in other embodiments, not shown, additional combustible
material, such as natural gas, oil, charcoal, or
any other fuel may be fed into the reaction chamber (in addition to the
carbonaceous fuel) in order to facilitate initial
system start-up or reactor temperature maintenance. The use of such additional
fuel(s) may also be used to provide
additional reforming reaction material or to change the hydrogen/carbon
dioxide output ratio of the system. All such
embodiments are envisioned to be within the scope of the present invention.

1104] Again, although both an indirect (Fig. 3) and an autothermal (Fig. 4)
reformer are shown here for
completeness, the present invention is best practiced with an indirect
reformer (Fig. 3), since in an indirect reformer,
the high-pressure gas does not have nitrogen from air mixed with the generated
hydrogen and carbon dioxide, which
aids the separation process (described below), and does not require the
separation of oxygen from air.

VARIETY OF CARBONACEOUS FUELS

11051 Embodiments of the present invention provide processes for producing
high-pressure gas from the
reforming of carbonaceous fuel or derivatives of carbonaceous fuel (as
described above). Examples of fuel sources
that may be used in the reforming reaction include, but are not limited to,
biomass, coal, urban and municipal trash,
forestry residue, methanol, ethanol, propane, propylene, toluene, octane,
diesel, gasoline, crude oil, and natural gas,
and in general any carbonaceous (or carbon-containing) compound. A similar
subsystemapparatus may be used to
reform these fuels.

11061 The present invention provides reforming processes of carbonaceous fuel
or carbonaceous fuel-derivatives
to generate, for example, H2, CO2, and other gases. The fuel reforming
reactions of the present invention are
endothermic, requiring an input of energy to drive the reaction toward fuel
reformation.

[1071 In one embodiment, the energy required to drive the carbonaceous fuel
reforming reaction is provided
through the combustion of any combustible material, for example, hydrogen, an
alcohol, a refined petroleum
product, crude petroleum, natural gas, or coal that provides the necessary
heat to drive the endothermic steam
reforming reaction.

[1081 In other embodiments, the energy required to drive the reforming
reaction is provided via any non-
combustible source sufficient to generate enough heat to drive the reforming
reaction to substantial completion.
Examples of non-combustible sources include solar, nuclear, wind, grid
electricity, or hydroelectric power.

[1091 In a preferred embodiment, shown in Fig. 1, a portion of the hydrogen
gas generated by the reformer is
used in the combustion chamber (furnace) to provide heat for the steam
reformer.



CA 02739420 2011-05-09

[1101 Reactions 1-6 above provided illustrative processes for reforming
carbonaceous fuel to produce high-
pressure gas. Various fuels, such as biomass, coal, alcohols, petroleum,
natural gas, etc. may be used as the fuel
source for the reforming reaction. Reactions 7-13 illustrate several other
reforming reactions using alternative fuel
sources that are in accordance with the present invention. The following
reactions illustrate a separation of the
reforming and combustion reactions; however, as shown in Fig. 4, an
autothermal reforming reaction may be
accomplished by directly reacting the carbonaceous fuel with oxygen in a
single reaction chamber.

Coal: C + 2H2O = CO; + 2H2 (7)
Methane: CH4 + 2H,O = CO2 + 4H3 (8)
Ethanol: C7H5OH + 3H2O = 2CO2 + 6H, (9)
Propane: C3H8 + 6H2O = 3CO2 + l OHS (10)
Propylene: C3H6 + 6H9O = 3CO2 + 9H2 (11)
Toluene: C7H8 + 14H2O = 7CO2 + 18H2 (12)
Octane: C8H18 + 16H,O = 8CO2 + 25H, (13)

11111 In alternative embodiments, olefins, paraffins, aromatics (as found in
crude petroleum), or crude petroleum
itself may be used as the reforming reaction fuel source.

FUEL REFORMER SUBSYSTEM DESIGN OPTIONS

11121 The present invention provides for at least three possible carbonaceous
fuel-steam reformers, but is not
limited to the three carbonaceous fuel reformers described here. These include
the fixed-bed reformer (Fig. 5), the
fluidized-bed reformer (Fig. 6), and the entrained-flow reformer (not
illustrated). The carbonaceous fuel reformers
increase in complexity in the order listed. The solids-residue handling
requirements also increase in complexity in
the same order. However, reaction rates also increase in the same order,
leading to reduced equipment sizes for a
given throughput. Each carbonaceous fuel-steam reformer may be implemented as
an indirect reformer
configuration (as shown in Fig. 3), or as an autothermal reformer
configuration (as shown in Fig. 4).

11131 Table I shows important features that distinguish the three possible
carbonaceous fuel-steam reformers.
Values are shown to illustrate relative differences in the reformer
parameters.

16


CA 02739420 2011-05-09

Table 1. Operating parameters of various carbonaceous fuel-steam reformers

Fixed-Bed Fluidized-Bed Entrained-Flow
Operating
Reformer Reformer Reformer
Parameter
(Fig. 5) (Fig. 6) (not illustrated)
Feed Particle Size approx. <1" approx. <1/4" approx. <0.1"
Temperature approx. >700 C approx. >800 C approx. >1,200 C
Solids Retention Time greatest intermediate shortest

Gas Retention Time longest shorter shortest

11141 All three carbonaceous fuel-steam reformers operate at sufficient
temperature to eliminate catalyst
requirements for steam reforming. The fixed-bed and fluidized-bed reformers
are able to accept carbonaceous fuel
of the delivered particle size. The entrained-flow reformer would require
additional grinding or pulverizing of the
carbonaceous fuel after delivery.

11151 In one embodiment of the present invention 500, depicted in Fig. 5, a
fixed-bed fuel-steam reformer 501 is
used to generate high-pressure gas. In the reaction chamber of the fixed-bed
reformer, nearly all the feed and residue
particles remain in reaction chamber 501 during reforming. Delivered
carbonaceous fuel502 with a feed particle size
of approximately less than 1-inch is introduced into hopper 503. The
carbonaceous fuel502 is then fed into fixed-bed
reformer 501 through feeder 504.Steam (shown as arrow 506) is also fed into
the fixed-bed reformer 501. In one
embodiment, heat recovered from the reformer gas is directed into heat
recovery unit 507. The heat can be sent to
steam generator 510 to convert water (shown as arrow 508) into steam (shown as
arrow 506). Furnace 505, which
may be fueled by hydrogen and/or carbonaceous material provides the necessary
heat to drive the reformer 501.
11161 The fixed-bed reformer can be fed and discharged in batch mode, semi-
batch mode (incremental feeding
and discharging of ash), or continuous mode. In the fixed-bed reformer, the
coarse ash 514 remaining after steam
reforming is largely handled in the form of coarser particles that can be
removed from the bottom of the reactor.
Coarse ash 514 can be considered a byproduct in the system with a clast size
greater than .063 millimeters. Smaller
remaining amounts of ash are entrained in the low velocity exhaust gas exiting
the reformer. This fine ash510of clast
size less than .063 millimeters is removed through bag filter 512. The
filtered, high-pressure gas is then sent to gas
separator 514, which separates the high pressure gas into a fraction rich in
CO2 gas, and a fraction rich in H. (fuel
gas).The CO-rich gas may then be easily sequestered and/or put to beneficial
use 520, since it is high-pressure,
high-purity CO2. The H,-rich fuel gas, which may also contain minor amounts of
methane and carbon monoxide,
may then be fed to gas turbine 516,where it is combusted with air to provide
electricity to the electric grid 518.

17


CA 02739420 2011-05-09

Since the H2-rich fuel gas combusts with little or no associated CO2 emissions
into the atmosphere, the electricity
generated by gas turbine 516 may be considered to be "carbon-free"
electricity.

11171 In an alternative embodiment 600, depicted in Fig. 6, a fluidized-bed
reformer 601 is used to generate high
pressure gas. In the fluidized-bed reformer 601, most particles remain in the
reaction chamber, but finer particles
are entrained with the exhaust gas. That is, compared to the fixed-bed
reformer 501 of Fig. 5, greater amounts of
fine particles are entrained in the higher velocity exhaust gas (relative to
the exhaust gas generated in the fixed-bed
reformer) and must be removed prior to compression of the driver gas. The
coarsest of the entrained particles are
removed from the gas stream and can be recycled to the reformer or discharged
as residue. The remaining finest
particles are removed by filtration.

11181 Fig. 6 illustrates an example of an embodiment of a system utilizing the
fluidized-bed reformer 601.
Delivered carbonaceous fue1602 with a feed particle size of approximately less
than '/4-inch is introduced into
hopper 603. The carbonaceous fuel is fed into fluidized-bed reformer 601 upon
opening of the rotary valve 604. In
the fluidized-bed reformer,steam (shown as arrow 606) is also fed into the
reaction chamber. Furnace 605, which
may be fueled by hydrogen and/or carbonaceous fuel, provides the necessary
heat to drive the reformer 601. It is
noted that in the fluidized-bed reformer 601, continuous feeding with semi-
continuous discharge of coarser ash 607
is preferable. Intermediate ash 608 in exhaust gas exiting the fluidized-bed
reformer 601 is removed by cyclone
separator 609 (to remove intermediate-sized particles) and bag filter 610 (to
remove the finest particles of ash 611).
The intermediate-sized particles separated by cyclone 609 can be recycled to
the fluidized-bed reformer 601 or
removed as residue, depending on the extent of their conversion during
reforming. In one embodiment of the
fluidized-bed reformer 601, exhaust gas existing cyclone 609 enters heat
recovery unit 614. The heat can be sent to
steam generator 615 to convert water (shown as arrow 616) into steam (shown as
arrow 606). The CO2 separator
618 separates the high pressure gas into a C02-rich gas and a H2-rich fuel
gas. The C02-rich gas may then be
directed for storage via sequestration and/or for beneficial use624. The H2-
rich fuel gas may then be provided to a
gas turbine 620. The gas turbine 620 combusts the H2-rich fuel gas with air to
generate electricity,using for example
a generator (not shown),which electricity is then fed to the electrical grid
622. Since the H2-rich fuel gas combusts
with little or no associated CO, emissions into the atmosphere, the
electricity generated by gas turbine 620 may be
considered to be "carbon-free" electricity.

11191 In another embodiment of the present invention (not illustrated), an
entrained-flow reformer is used rather
than a fixed-bed or fluidized-bed reformer. In an entrained-flow reformer,
virtually all particles are removed with
the exhaust gas steam exiting the reformer. The feed particle size using the
entrained-flow reformer is generally less
than approximately 0.1-inch. Compared to the fixed-bed and fluidized-bed
reformers, the entrained-flow reformer
would require additional grinding or pulverizing of the carbonaceous fuel
after delivery. Furthermore, with the
entrained-flow reformer, the entire feed stream is entrained and removed from
the reaction chamber at high velocity.
Cyclone and filtration hardware similar to those of the fluidized-bed reformer
are used, but removal capacities must
be greater.

18


CA 02739420 2011-05-09

11201 In other embodiments of the present invention, (not illustrated in Fig.
5 or Fig. 6),carbonaceous fuel-water
slurry may be used to provide both carbonaceous fuel and water into the
reformer in liquid form via a single feed
system, as shown in Fig. 3 and Fig. 4.

11211 In all carbonaceous fuel-steam reformers described, the reformers
operate at sufficient temperature to
eliminate catalyst requirements for steam reforming. Generally, the fixed-bed
reformer may operate at temperatures
above approximately 700 C, while the fluidized-bed reformer may operate at
temperatures above approximately
800 C. The entrained-flow reformer may operate at temperatures in excess of
approximately 1,200 C. These
temperature ranges are illustrative only, and are not intended to limit the
scope of the present invention. All
carbonaceous fuel-steam reformers may operate over temperature ranges other
than those temperature ranges
disclosed here.

11221 The fixed-bed reformer 501 of Fig. 5 and fluidized bed reformer 601 of
Fig. 6 may be designed as
illustrated in Fig. 3 or Fig. 4. That is, the steam reforming of carbonaceous
fuel can be carried out using an indirect
reformer, as in Fig. 3, or a direct ("autothermal") reformer, as depicted in
Fig. 4. Indirect reforming requires heat
exchange between the heat source (H2 fuel combustion, for example) and the
reformer. High pressuregas produced
from indirect steam reforming results in greaterhydrogen:carbon dioxide ratio
than gas produced from direct
("autothermal") reforming. It will be appreciated that the combustible
material may be hydrogen (H2), or
alternatively may be an alcohol, olefin, natural gas, oil, coal, biomass or
other combustible source.

11231 Autothermal reforming eliminates the heat exchange requirement since
partial combustion is performed in
the reforming reaction chamber to generate heat. Using oxygen for the
oxidizer, the autothermal reformer product
gas is still a mixture of carbon dioxide and hydrogen, but the hydrogen:carbon
dioxide ratio is lower than that for
indirect reforming. Using air as the oxidizer, the autothermal reformer
product gas is diluted with nitrogen, which
may be undesirable in cases where high purity CO2 is required.

11241 Illustrative carbonaceous fuel reformers have been described and shown
here. However, the present
invention is not limited to these carbonaceous fuel reformer configurations,
and other carbonaceous fuel reformers
are within the scope of the present invention.

SULFUR REMOVAL

11251 Most carbonaceous fuelhas some sulfur. Because steam reforming is
performed without catalyst, reforming
catalyst poisoning by sulfur compounds is not an issue. In cases where a low-
sulfur carbonaceous fuel is used, sulfur
clean up of the exhaust gas may not be required at all. In the event of
potential issues with corrosion caused by
sulfur-containing gases in combination with any residual moisture, several
sulfur treatment and removal methods are
possible.

11261 Dry sorbents may be used to capture sulfur in the exhaust gas. Calcium
oxide, magnesium oxide, and
sodium carbonate are example dry sorbents that are capable of trapping sulfur
gases in solid form (as sulfates or
19


CA 02739420 2011-05-09

sulfites, depending on the relative oxidation conditions). When the operating
temperature and pressure permit
effective sulfur capture, sorbent can be added in a coarse form with the
feedstock to fixed- or fluidized- bed
reformer configurations. The resulting sulfur-containing product can then be
removed from the reaction chamber
with the ash remaining after reforming. Alternatively, a finer sorbent can be
injected into the gas downstream of the
reactor. Sulfur containing solids can then be collected in the cyclone or bag
filter. For the entrained-flow reformer
configuration, a sorbent will likely perform better by injection into
partially cooled gas downstream of the reformer.
1127] In large-capacity reformer configurations, a dry sorbent may be injected
in a separate unit downstream of
the final ash particulate filter. The sulfur product can then be collected
separately in another filter and can potentially
be sold as a product for additional revenue.

1128] In other embodiments, sulfur may also be removed by using a wet scrubber
sub-system. Wet scrubbers can
be configured in venturi, packed-column, or tray-type systems in which the
cooled gases are contacted with a
scrubbing solution or slurry. The resulting scrubber solution or slurry must
then be disposed.

]129] The use of the methanol CO2 separation system described below has the
additional benefit of removing
sulfur impurities from the CO2 gas stream.

PREFERRED CO, SEPERATION SUBSYSTEM

]130] According to the present invention, highly economic CO2 and H2
generation system is created. The CO2
and H2 are generated from any carbonaceous fuel source including biomass or
coal, a highly economical fuel source
and one that is available almost everywhere. The CO2 generated in the present
invention may be injected into an oil
well for enhanced oil recovery or used for other beneficial purposes. The
present invention also generates large
supplies of hydrogen, which may be split off from the CO, product to be used
for many purposes, including
electrical power generation or petrochemical hydrogenation.

]131] In an alternative embodiment, the hydrogen gas may be sold to the
petrochemical or other industry. In the
future, it may also be sold as a fuel for hydrogen-electric cars.
Alternatively, the hydrogen may be burned, using for
example a gas turbine, to generate electricity. The electricity may be sold to
utility companies by feeding the
electricity into the electric grid.

11321 Carbon dioxide is approximately two orders of magnitude more soluble in
methanol than any of methane,
hydrogen, nitrogen, oxygen, or carbon monoxide (which all have solubilities of
the same order). The methanol also
acts as a trap, removing sulfur impurities from the gas stream. In experiments
done to date, inventors have shown
that at 10 bar pressure and 10 C, methanol will take in to solution about 40
grams per liter of CO2 from a 40%
CO2/60% N_, gas mixture, with less than 2 grams/liter of N2 entrained.

]133] Inventors have used this data to create a system where liquid methanol
is pumped in a cycle from 1 bar to
bar, with the gas mix being bubbled through a column on the 10 bar side, and
captured gas allowed to outgas


CA 02739420 2011-05-09

from solution on the 1 bar side. Results to date show that product gas
purities of 95% CO2 can be obtained, with
80% of the input CO2 in the feed gas stream being captured into the product
stream. The fraction captured could be
increased further to better than 95% by heating the methanol in the low
pressure tank to 40 C, which could be
readily done using low quality waste heat from either the steam reformer or
power generation systems. Warming the
methanol in this manner would increase the methanol vapor pressure in the
exhaust to about 0.3 bar, but nearly all of
the entrained methanol vapor could be condensed and removed by running a low-
cost (commercial meat freezer
technology) -18 C refrigerator downstream of the exhaust vessel. This unit
would also reduce the CO2 temperature
to -18 C, which is advantageous, as it allows CO2 gas to be liquefied by
subsequent compression to only 20 bar.
11341 However, in order to eliminate the large majority of this compression
energy work, reduce methanol
recirculation pump work by an order of magnitude, and to obtain both CO2
product recoveries and purities of better
than 97%, a preferred system configuration may be used that uses methanol
cooled to -60 C in the absorption
column. Such a column can acquire CO2 in the liquid phase, forming mixtures
that are more than 30% CO2 by
weight, with only insignificant qualities of non-CO2 gases brought into
solution. Upon being warmed in the
desorption column to 40 C, nearly all the CO2 is stripped, and removed from
the system at 10 bar, making
subsequent liquefaction very straightforward. In the preferred embodiment, the
heating of the methanol occurs at the
bottom of the downflowing desorption column, with cold CO2-saturated methanol
on top, so that very little
methanol vapor escapes with the product CO2.

11351 In the process of liquefaction, nearly pure CO2 is obtained, as neither
hydrogen, methane, oxygen, nitrogen,
nor carbon monoxide will be liquefied at -60 C. Once the CO2 is liquefied, it
can be brought to whatever high
pressure is required for underground injection at little energy cost.

11361 The non-CO2 product gases, which will be a mixture of hydrogen, methane,
and small amounts of carbon
monoxide, is sent directly to a gas turbine where it is burned to produce
electricity for sale to the grid.
ALTERNATIVE CO,SEPARATION SUBSYSTEMS

11371 Various alternative techniques may be used to separate hydrogen gas from
carbon dioxide gas, in additional
to the methanol-CO, separation technique described above. In one embodiment,
hydrogen-carbon dioxide separation
may be performed using membranes. The membranes separate molecules based on
their relative permeability
through various materials that may include polymers, metals, and metal oxides.
The membranes are fed at elevated
pressure. The permeate is collected at lower pressure while the retentate is
collected at a pressure close to the feed
pressure.

11381 A membrane separation technique that may operate in conjunction with
reactions at elevated temperature is
the palladium membrane. This membrane, which may be fabricated using palladium
alone or in combination with
modifiers, allows only hydrogen to permeate. This type of membrane, when
operated in a catalytic reactor, such as
21


CA 02739420 2011-05-09

in a steam reformer, enhances yield by removing a reaction product from the
reaction zone. Some variants are
capable of operation at up to 900 C.

11391 Another membrane separation method that may be used is a high-
temperature polymer membrane. This
type of membrane is directed toward CO2 separation and recovery. A polymeric-
metal membrane of this type can
operate at up to 370 C (versus typical maximum polymer membrane temperatures
of about 150 C), thus potentially
improving process energy efficiency by eliminating a pre-cooling step.

11401 In yet another embodiment, carbon dioxide may be separated from hydrogen
by scrubbing in an amine
solution. This technique may be used to remove carbon dioxide (and hydrogen
sulfide) from the high-pressure gas.
11411 Finally, in yet another embodiment, regenerable sorbents may be used to
separate hydrogen gas from
carbon dioxide gas. In one example of a low-cost regenerable sorption method,
a sodium carbonate sorbent is used.
The sodium carbonate sorbent operates cyclically, by absorbing at about 60 C
and regenerating at about 120 C.
1142] As described in the preferred CO2 separator section, processes that
generate high CO2 concentrations are
more amenable to affordable gas separation. Elimination of diluents such as
nitrogen from air greatly improves CO2
capture efficiency. In addition, processes that produce CO2 at elevated
pressure are at an advantage for the pressure-
based separation techniques.

11431 Various gas separator modules may be used, and the present invention is
not limited to the particular gas
separators shown or described herein, so long as the gas separators perform at
least the function of separating CO2
from the rest of the driver gas.

SYSTEM DESIGN USING A MODULAR CONFIGURATION

11441 The present invention may also be configured as a modular system, which
may include all or part of the
following set of components: a steam reformer, a gas separator, heat
exchangers, a power generator, and a control
system. These components may be mixed and matched depending on the particular
application, and the
requirements of a particular user. These components are described in detail
throughout this disclosure.

11451 A carbonaceous fuel reformer module is provided that is capable of
reacting carbonaceous fuel with water
to produce a mixture of CO2 and hydrogen gas, sized to an output rate
appropriate for the application. Depending
upon the availability and cost of local carbonaceous fuel types, the reformer
may be designed to operate with various
candidate carbonaceous fuelfeed-stocks. The carbonaceous fuel reformer may be
designed as a fixed-bed reformer,
a fluidized-bed reformer, an entrained-flow reformer, or another design
altogether. The carbonaceous fuel reformer
may be designed in a direct reforming configuration, or an indirect
("autothermal") reforming configuration.
Examples of the design of such carbonaceous fuel reformers are discussed above
in relation to Figs. 3-6.

22


CA 02739420 2011-05-09

11461 A set of heat exchangers is provided that are designed to maximize the
thermal efficiency of the reformer
system. The heat exchangers were discussed above in relation with the fuel
reformers of Figs. 3 and 4.

[1471 A gas separator module is provided that is capable of separating the CO7
from the hydrogen gas. Candidate
separator systems include methanol temperature and/or pressure swing, sorption
beds, CO2 freezers, membranes,
and centrifugal separators, as described above.

[1481 A power generator module is provided that is capable of utilizing the
hydrogen product separated by the
gas separator to generate electricity. The power generator may be a gas
turbine, an internal combustion engine, a
fuel cell system, or any other apparatus or system that can generate power
(electrical or mechanical or other) from
hydrogen, methane, and/or carbon monoxide gas.

[1491 A control module is provided that is capable of controlling the
operation of the system both automatically
and with user-input. The control module may use subsurface data to
automatically regulate the operation of the
system via feedback control. This allows the system to operate with minimal
human supervision or labor. The
subsurface data may include total pressure, partial pressure of carbon
dioxide, partial pressure of hydrogen,
temperature, and/or viscosity of the oil. The control module may also include
a set of controls for user-control of
the system.

11501 The control system may be used to control the power plant based on the
local prices of electricity,
carbonaceous feedstock, water, and the value of the product produced via the
beneficial reuse of CO2. That is, if the
local price of electricity has increased and/or there is a demand for more
power, the control system may divert more
of the hydrogen to electricity generation. The opposite condition may hold if
the local price of electricity dropped or
if the market price of the product produced via the beneficial reuse of CO2
rose; in this case the control system may
divert more of the hydrogen gas and CO2 gas for beneficial use. This
optimization operation may be performed
automatically by a control module based on real-time inputs of market prices
and other parameters.

[1511 A gas capture module is provided that is capable of re-capturing a
portion of the CO2 gas and recycling the
gas. The gas capture module allows the CO2 that is released with the oil
emerging from the ground to be re-captured
and sent via the compressor module underground for reuse. The gas capture
module increases the overall efficiency
of an oil recovery operation, because a portion of the generated CO2 gas is
recycled and reused.

11521 In one embodiment, a gas capture module is created by pumping the oil
into a vessel with a certain amount
of ullage space above the oil, and drawing suction on the tillage with another
pump. This operation will lower the
vapor pressure of carbon dioxide above the oil, allowing gases in solution to
outgas so that they can be recycled
back into the well. Various gas capture modules are within the scope of the
present invention, and the present
invention is not limited to the particular gas capture modules or methods
shown or described here, as long as the gas
capture modules or methods are capable of capturing at least a portion of the
gas emerging with the oil from the oil
well.

23


CA 02739420 2011-05-09

11531 Fig. 7 illustrates an example of a modular embodiment of the present
invention 700 having one or more
modules. For example, any of a number of reformer modules may be used. A
biomass fuel reformer module 702
and a coal fuelreformer module 704 are shown for illustrative purposes only.
Any heat exchange module, such as
heat exchanger 706, may be used. Any gas separator module, such as methanol
CO2 separator module 708 or
sorption bed 710, may be used. Any power generator module, such as gas turbine
712 or fuel cell 714, may be used.
Any compressor module, such as compressor 718, may be used if even higher CO2
pressure is required, for example
5,000-10,000 psi for deep FOR or deep saline aquifer injection. High-pressure
gas exits the compressor module 716
via port 718.

POWER GENERATION SUBSYSTEM

[1541 The hydrogen gas separated by the gas separator module may be used to
generate power. The power
generator module utilizes a portion of the hydrogen gas separated by the gas
separator module to generate power. In
one embodiment, the power generator module is used to generate electricity. In
one embodiment, the electricity is
sold to a utility company by feeding the electricity into the electric grid.
The power generator module may be a
combustion turbine, a steam turbine, a fuel cell, or any other apparatus,
system, or module that can generate power
(electrical or mechanical or other) from hydrogen gas.

[1551 According to one embodiment of the power generator module utilizing a
combustion turbine, hydrogen is
fed with air to generate power through a rotating shaft. Designs of hydrogen
gas turbine plants are described in U.S.
Patent 5,755,089 to Vanselow, U.S. Patent 5,687,559 to Sato, and U.S. Patent
5,590,518 to Janes. Designs of
hydrogen internal combustion engines are described in U.S. Patent 7,089,907 to
Shinagawa et al., U.S. Patent
4,508,064 to Watanabe, and U.S. Patent 3,918,263 to Swingle.

11561 Another embodiment of the power generator module uses a steam turbine. A
variety of fuels may be used,
including a portion of the separated hydrogen, part of the coal or other
feedstock material, or even waste
hydrocarbon gases. The fuel is burned in air in a combustion chamber to
generate heat. The heat is transferred to a
closed-loop steam/water system through a series of heat exchangers designed to
recover the combustion heat. The
high-pressure steam drives a turbine for power generation. In one embodiment,
the combustion turbine and steam
turbine may be integrated to boost efficiency (integrated combined cycle).

11571 As an alternative to combustion, in one embodiment of the present
invention, a fuel cell module may be
used to convert hydrogen directly to electricity, usually with greater
efficiency albeit at a higher capital cost. The
fuel cell module, an electrochemical energy conversion device, produces
electricity from the hydrogen fuel (on the
anode side) and oxidant (on the cathode side). The hydrogen and oxidant (which
may be ambient oxygen) react in
the presence of an electrolyte. The reactants (hydrogen and oxygen) flow in
and reaction products (water) flow out,
while the electrolyte remains in the cell. The fuel cell can operate virtually
continuously as long as the necessary
flows of hydrogen and oxidant are maintained. Designs of fuel cell plants are
described in U.S. Patent 6,893,755 to
Leboe, U.S. Patent 6,653,005 to Muradov, U.S. Patent 6,503,649 to Czajkowski
et al., U.S. Patent 6,458,478 to
24


CA 02739420 2011-05-09

Wang et al., U.S. Patent 5,079,103 to Schramm, U.S. Patent 4,659,634 to
Struthers, and U.S. Patent 4,622,275 to
Noguchi et al.

11581 Various power generator modules are within the scope of the present
invention, and are not limited to the
particular power generators shown or described here, so long as the power
generators can generate power, whether
electrical, mechanical, or other, from hydrogen-rich gas.

BENEFITS OF BIOMASS REFORMATION AND OTHER EMBODIMENTS

11591 Fig. 8 illustrates a scenario (800) where a power plant operating in
proximity to an oil field or other
beneficial user of Muses a biomass-steam reforming plant according to the
principles of the present invention. In
one illustrative example, a plant is built that is capable of generating ten
million cubic feet of CO2 a day (or 10,000
kcf or 10 MMcf) and 14,000 kcf (or 14 MMcf) of hydrogen. In this scenario, the
CO2 is sequestered underground in
the field, generating about 1,000 extra barrels of oil per day while the
hydrogen is burned on site to generate
approximately 25 MW of emissions-free, electricity which is sold to a local
utility grid. In the discussion below, the
figure illustrates the amount of CO, sequestered for each day of operations of
such a 25MW power plant built using
the principles of the present invention.

11601 In Fig. 8, atmospheric CO2 is captured by plant matter during the course
of the natural carbon cycle (802).
The carbon ends up in the plant matter biomass (804), which is harvested for
use in the power plant. About 307,000
kg of biomass (806), which contains about 138,000 kg of carbon, is fed into
the power plant (808) per day. The
power plant (808) generates about 10 MMcf of CO2per day (810), which is used
to extract an extra 1,000 barrels of
oil from the oil field per day, or alternatively is used to produce some other
beneficial product (812). One barrel of
oil contains about 120 kg of carbon, out of which, on average, about 103 kg is
released as CO2 when the oil is
consumed. Thus, about 103,000 kg would be released if all of the oil was later
combusted, for example, in a vehicle
during driving. Therefore, about 30% more carbon is sequestered underground
(138,000 kg/day) than is released
when the oil is ultimately consumed (103,000 kg/day). The hydrogen-rich fuel
gas (814) is fed to the gas turbine
(816), which generates about 25 MW of electricity (818) that is fed to the
electric grid (820). This example is
illustrative of only one of many embodiments of the invention, and is not
intended to limit the invention to just
scenarios in which this type of biomass configuration is used. Therefore, the
invention includes embodiments in
which negative, zero, as well as positive carbon emissions are possible,
depending on the fuel used and scenario.
11611 Therefore, according to one broad aspect of one embodiment of the
present invention, both carbon-negative
oil and carbon-free electricity may be generated using the principles of the
present invention in an economical and
financially profitable manner. In fact, using the principles of the present
invention, any carbon-intensive industrial
process can be turned into a low-carbon intensive process, or even a carbon-
negative process, by utilizing the
principles taught in the present invention.



CA 02739420 2011-05-09

11621 Accordingly, another embodiment of the present invention is a
hydrocarbon, which when combusted,
releases less carbon dioxide than the amount of carbon dioxide sequestered
underground during a process of
extracting the hydrocarbon.

11631 Yet another embodiment of the present invention is a petroleum product
extracted by a process comprising
the steps of injecting carbon dioxide into an injection well, and recovering
the petroleum product from a production
well, where an amount of carbon dioxide injected into the injection well is
greater than or equal to an amount of
carbon dioxide released into the atmosphere when the petroleum product is
combusted.

[1641 Yet another embodiment of the present invention is a method for removing
carbon dioxide from the
atmosphere, and hence helping mitigate global warming, the method comprising
the steps of. providing a
carbonaceous fuel reaction apparatus; providing carbonaceous fuel for the
carbonaceous fuel reaction apparatus;
generating carbon dioxide gas from the carbonaceous fuel using the
carbonaceous fuel reaction apparatus; and
utilizing the carbon dioxide gas in a manner that substantially does not
release the carbon dioxide gas into the
atmosphere.

11651 Another embodiment of the present invention is the method above, where
the carbon dioxide gas is used to
grow algaeand/or plants in greenhouses. Yet another embodiment of the present
invention is the method above,
where the carbon dioxide is sequestered underground in a saline aquifer,
depleted oil field, depleted gas field,
and/orunmineable coal seam. Yet another embodiment of the present invention is
the method above, where the
carbon dioxide is used for enhanced oil recovery (EOR), enhanced gas
recovery,and/or enhanced coal-bed methane
recovery. Yet another embodiment includes sequestering the CO2 in the oceans.

11661 Yet another embodiment includes using the CO2 for fuel production.

11671 In yet another alternative embodiment of the present invention, the
principles of the present invention may
be used to retrofit an existing natural gas-fired power plant to work with
biomass and/or coal, while reducing CO2
emissions. Natural gas power plants, especially natural gas combined cycle
power plants, are gaining in popularity
because of their higher efficiencies and less carbon dioxide emissions as
compared to coal-fired power plants.
Unfortunately, the price of natural gas is highly volatile, being coupled to
the volatility of petroleum prices.
Therefore, it would be advantageous to utilize coal and/or biomass as a
feedstock in a natural gas combined cycle
plant without losing the thermal and environmental efficiencies of a natural
gas combined cycle plant. The
principles of the present invention may be used to create a high-pressure
stream of H, and a high pressure stream of
CO,, which may be easily sequestered or beneficially utilized. The H2 may then
be fed into a traditional natural gas-
fired combined cycle power plant, hence retrofitting an existing natural gas
power plant to run on coal and/or
biomass, which is a fuel significantly cheaper than natural gas and without
the price volatility. In addition, the H,
burns even cleaner than the original natural gas, and therefore the present
invention may be used to retrofit a natural
gas power plant to run on hydrogen, while sequestering nearly 100% of the CO2
in the coal and/or biomass used as
the fuel source.

26


CA 02739420 2011-05-09

11681 As an alternative to using a reforming reaction to generate high
pressure gas, it is an alternative
embodiment of the present invention to use combustion and/or gasification
followed by water-gas-shift reaction to
generate the gases, and still be within the spirit and scope of the present
invention. In general, a reforming reaction
is preferable to using combustion or gasification using air because either
reaction would produce driver gas mixed
with large amounts of nitrogen from air, which is undesirable. As an
alternative to using air-blow combustion or
gasification, it is another embodiment of the present invention to use oxygen-
blown combustion or gasification, and
still be within the spirit and scope of the present invention. In general, a
reforming reaction is still preferable to
using oxygen-blown combustion or gasification, because in either case, a
source of pure oxygen is required, which
must be separated from air, introducing an additional expense.

(1691 While the methods disclosed herein have been described and shown with
reference to particular operations
performed in a particular order, it will be understood that these operations
may be combined, sub-divided, or re-
ordered to form equivalent methods without departing from the teachings of the
present invention. Accordingly,
unless specifically indicated herein, the order and grouping of the operations
is not a limitation of the present
invention.

11701 While the present invention has been particularly shown and described
with reference to embodiments
thereof, it will be understood by those skilled in the art that various other
changes in the form and details may be
made without departing from the spirit and scope of the present invention.

27

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

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Administrative Status

Title Date
Forecasted Issue Date 2013-02-05
(22) Filed 2011-05-09
Examination Requested 2011-07-15
(41) Open to Public Inspection 2011-09-20
(45) Issued 2013-02-05
Deemed Expired 2019-05-09

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Registration of a document - section 124 $100.00 2011-05-09
Application Fee $200.00 2011-05-09
Request for Examination $400.00 2011-07-15
Final Fee $150.00 2012-11-22
Maintenance Fee - Patent - New Act 2 2013-05-09 $100.00 2013-03-21
Maintenance Fee - Patent - New Act 3 2014-05-09 $50.00 2014-04-15
Maintenance Fee - Patent - New Act 4 2015-05-11 $50.00 2015-03-04
Maintenance Fee - Patent - New Act 5 2016-05-09 $300.00 2016-09-15
Maintenance Fee - Patent - New Act 6 2017-05-09 $100.00 2017-04-13
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
PIONEER ENERGY, INC.
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Description 2011-07-15 27 1,476
Representative Drawing 2011-09-09 1 10
Cover Page 2011-09-09 2 50
Abstract 2011-05-09 1 21
Description 2011-05-09 27 1,470
Claims 2011-05-09 6 152
Drawings 2011-05-09 8 107
Claims 2012-05-24 6 195
Cover Page 2013-01-16 2 50
Correspondence 2011-07-26 1 13
Correspondence 2011-05-19 2 81
Prosecution-Amendment 2011-07-15 2 83
Correspondence 2011-07-15 4 155
Prosecution-Amendment 2011-07-15 4 120
Assignment 2011-05-09 7 238
Prosecution-Amendment 2012-01-24 1 21
Prosecution-Amendment 2012-02-28 2 52
Prosecution-Amendment 2012-05-24 17 517
Correspondence 2012-11-22 1 60
Fees 2013-03-21 1 56