Title of Invention

A METHOD FOR EFFECTING THE ENERGY CONVERSION OF SOLID FUELS CONTAINING CARBON

Abstract The invention relates to a method for effecting the energy conversion of solid fuels containing carbon comprising : reacting the solid fuels with oxygen provided by oxide particles to create flue gases and unconverted compounds in a first oxide reduction reactor having an exit, wherein the first oxide reduction reactor comprises a first circulating fluidized bed; oxidizing oxide particles in an oxide oxidation reactor, wherein the oxide oxidation reactor comprises a second circulating fluidized bed; providing flue gas and particles from the exit of the first oxide reduction reactor directly to an inlet duct of a gas-solid separation cyclone, the separation cyclone also having a roof, and an exit, wherein the separation cyclone rotates the flue gases, oxide particles and unconverted compounds to create increase residence time within the cyclone and to separate out the oxide particles and convey the separated oxide particles to the oxide oxidation reactor; injecting oxygen into the separation cyclone of the first oxide reduction reactor to convert unconverted compounds exiting the first oxide reduction reactor, and circulating the oxide particles between the oxide oxidation reactor and the first oxide reduction reactor for conversion of the fuel and oxidization of the oxide particles.
Full Text Method for energy conversion minimizing oxygen consumption
The present invention relates to a method of energy
conversion of solid fuels containing carbon.
The emission of greenhouse gases, in particular CO2,
in power stations using fossil fuels must increasingly be
brought under control. Controlling such emission entails
solving new problems such as capturing the CO2 in the flue
gases of power stations using fossil fuels or in the gases
from installations using biomass type renewable energy
sources (non-fossil carbon) for the production of
substitute fuels usable in transportation, and all of the
above combined while minimizing the cost and minimizing
the modification of existing installations.
Finally, the progressive depletion of oil fields is
generating a dynamic for the large scale deployment of
recovery techniques assisted by injecting CO2 that are
capable of doubling the extraction capacities of
accessible reserves.
To this end, it is known in the art to use oxygen
and steam to convert solid fuels containing carbonaceous
materials by autothermic gasification to produce a syngas
containing CO and H2 that may be used in gas turbines,
hydrogen production units or units for synthesizing
methanol type compounds.
The above type of installation is described in our
patents FR 2 660 415 and FR 2 559 776. However, the
presence of unconverted tar or fine unburned carbon
particle type hydrocarbons in these installations creates
unwanted condensation and unwanted components in the
cooling and syngas processing systems and degrades the
yield from such installations.
To eliminate the tar and unburned carbon, the syngas
is subject to a thermal reforming process by increasing
the temperature resulting from partial combustion, which

necessitates an additional supply of secondary oxygen.
As described in our US patent 6,505,567, it is also
possible to convert these solid fuels energetically by
employing combustion processes using oxygen and recycled
CO2, rather than external air, which produces combustion
flue gases containing principally CO2 and steam, with no
nitrogen, in order to be able to use these flue gases for
operations of assisted recovery of subterranean petroleum
or to enable their subterranean storage. However, these
processes consume a great deal of oxygen, which must be
produced by a dedicated air distillation unit using some
of the energy produced, and therefore adding to the
electrical energy consumption burden.
Also known in the art is using thermochemical cycles
in combustion processes for converting solid fuels
containing carbonaceous materials to produce combustion
flue gases containing principally CO2 and water. With this
solution, it is not necessary to use a dedicated air
distillation unit, but a problem arises from the presence
in the combustion flue gases of unconverted carbonaceous
compounds, such as hydrocarbons (CnHn) or unburned carbon,
which are unacceptable for assisted petroleum recovery
processes or subterranean storage and must be eliminated.
The object of the present invention is to propose an
energy conversion method that minimizes the consumption of
oxygen and minimizes the production of unconverted
carbonaceous compounds.
The method of the invention is a method of energy
conversion of solid fuels containing in particular carbon,
comprising a first step of reacting said fuels in a first
energy conversion reactor, characterized in that it
comprises a second step of injecting oxygen at the exit
from said reactor, the reaction of the first step being
effected in at least one circulating fluidized bed and in
that, to convert the fuel and oxidize the oxide, metal

oxides circulate between two interconnected circulating
fluidized beds.
This second step converts practically all of the
residual hydrocarbons contained in the gases from the
first step into CO2, CO, H2 and steam in the case of a
gasification first step and into CO2 and steam in the case
of a combustion first step.
According to one feature, the reaction of the first
step is carried out in at least one circulating fluidized
bed. If there are two circulating fluidized beds they are
interconnected. A circulating bed facilitates the transfer
of mass and energy and thus the conversion of the fuels
with the reactants.
According to another feature, metal oxides circulate
between two interconnected circulating beds for conversion
of the fuel and oxidation of the oxides. The metal oxides
provide the additional oxygen necessary for the conversion
of the carbon and the hydrogen contained in the fuel
introduced into the conversion reactor.
In a first variant of the method, the energy
conversion of the fuel is effected by combustion. If the
quantity of oxygen entering the conversion reactor is
greater than the reactional stoichiometric quantity, the
conversion reaction is virtually total combustion, with
the exception of unconverted carbonaceous compounds.
In one particular arrangement of the first variant,
the injection of oxygen in the second step of the process
is effected in the gas-solid separation cyclone of the
fluidized bed. This cyclone is the site of intense
turbulence in which flue gases and circulating solids are
separated during a particular time spent in said cyclone.
It is therefore advantageous to introduce therein oxygen
from the second conversion step that combines with the
unconverted carbonaceous compounds present in the
combustion flue gases, such as hydrocarbons (CnHm) or

unburned carbon.
In a first arrangement of the first variant, the
oxygen is injected in the upper portion of the inlet duct
of the cyclone. This has the advantage of injecting this
oxygen into the gaseous phase of the flow containing the
compounds to be converted, as it is known that the solids
travel in the lower portion of this duct, and thereby
procures additional processing time for the conversion
reaction that takes place in the duct.
In a second arrangement of the first variant, the
oxygen is injected into the ceiling of the cyclone. This
offers the advantage that it develops a jet virtually
coaxial with the axis of the cyclone without risk of
impact on the walls.
In a third arrangement of the first variant the
oxygen is injected at the exit of the cyclone. This allows
injection into a gaseous phase that has a very low solids
content and whose residual rotation after centrifuging is
very suitable for a gaseous mixture with oxygen.
In a second variant, the energy conversion of the
fuel is effected by gasification. If the quantity of
oxygen in the conversion reactor is small, i.e. if it is
low compared to the reactional stoichiometric quantity,
then the reaction is one of partial gasification.
According to one particular feature of the second
variant, primary gasification is carried out during
thermochemical cycling. The thermochemical cycling is
effected by exchanging metal oxides between two
interconnected circulating fluidized beds. This cycle
enables the subsequent production of purified hydrogen.
In a first arrangement of the second variant, the
oxygen is injected in the second step through the ceiling
into the downward vertical gas flow cyclone reactor.
According to a second arrangement of the second
variant, the oxygen is injected substantially at the

center of the downward vertical gas flow cyclone reactor.
This injection develops a jet that is virtually coaxial
with the axis of the cyclone without risk of impacts on
the walls, and injection occurs where the residual
rotation of the gas to be converted resulting from the
first (centrifuging) step is very suitable for a gaseous
mixture with oxygen.
According to another variant of the invention, the
energy conversion method in accordance with the invention
for solid fuels containing carbon in particular comprises
a first step of reacting said fuels in an energy
conversion reactor and is characterized in that it
comprises two parallel channels for the reaction of said
fuels in two energy conversion reactors, with a second
step of injecting oxygen at the exit of said reactors, and
in that an oxide oxidation reactor simultaneously feeds
metal oxide particles in a controlled manner into the
reactor and the primary gasifier.
The invention will be better understood after
reading the following description, which is given by way
of example only and with reference to the appended
drawings, in which:
- figure 1 is a general view of a total conversion
or combustion system of the invention,
- figure 2 is a general view of a partial conversion
or gasification system of the invention, and
- figure 3 is a general view of a system for the
coproduction of electricity and hydrogen.
For simplicity, the same reference numbers are used
for the same items in the various figures.
The combustion installation 1 represented in figure
1 comprises an oxide reduction reactor 2, an oxide
oxidation reactor 3, two cyclones 4 and 5, each dedicated
to one reactor, two rear cages 6 and 7 containing recovery
exchangers for flue gases based on CO2 and for air, each

dedicated to one of the reactors. A bag filter 70, an
induced draught fan 71 and a stack 72 are disposed after
the rear pass 7. An ash and oxide separator 6 3 is placed
after the rear pass 6 to process the solids with a bag
filter 60, an induced draught fan 61 and a cooling and
condensation circuit 62 for pretreating the CO2. The
reactors 2 and 3 are interconnected to exchange oxide
particles .
The reduction reactor 2 is supplied with fuel from a
silo 8 via the bed 30. The reactor 3 is supplied from a
silo 9 via two circulating fluidized beds 40 and 30.
The reactor 2 is fluidized by a mixture made up of
steam and recycled CO2.
After reduction in the reactor 2, the oxides enter
the cyclone 5, where solid oxide particles are separated
from ash and combustion gases consisting of CO2, SO2 and
steam. The oxygen of the second process step is introduced
upstream of, in and/or downstream of the cyclone 5 via
respective pipes 50, 51 and 52. These three separate
injections of oxygen may be effected alone or in
combination to ensure total conversion of unconverted
compounds contained in the flue gases based on CO2 from the
reactor 2.
In the partial gasification installation 1'
represented in figure 2, there is for the first step of
the process a primary gasifier 20 or cyclone reactor and
an oxide oxidation reactor 3, two cyclones 4 and 500, the
first cyclone 4 being connected to the reactor 3 and the
second cyclone 500 being connected to the gasifier 20, a
rear cage 6 in series with the cyclone 4 of the reactor 3
containing syngas and air recovery exchangers. A bag
filter 60, an induced draught fan 61 and a stack 65 are
placed after the rear pass 6. The raw syngas extracted
from the cyclone 500 is directed to a secondary gasifier
5 01 into which the oxygen of the second step of the

process is injected, thereby eliminating tars and unburned
carbon by thermal reforming of the syngas at 90, i.e. by
increasing the temperature resulting from partial
combustion.
The primary gasifier 20 is fed with biomass from a
silo 8 0 via the bed 31, for example.
The oxide used in the reactor 3 is a metal oxide,
for example. The oxygen of the second step of the process
is injected into the secondary gasifier 501 by a pipe 503
to eliminate tars and unburned carbon by thermal reforming
of this syngas.
The system 1" represented in figure 3 comprises an
oxide reduction reactor 2, an oxide oxidation reactor 3, a
primary gasifier 20, and three cyclones 4, 5 and 50 0
respectively connected to the reactors 3 and 2 and to the
primary gasifier 20. The cyclone 500 is connected to a
secondary gasifier 501.
The reactor 2 is fed from a silo 8 via a fluidized
bed 30, the reactor 3 is fed from a silo 9 via the
circulating fluidized beds 40, 30 and 31, and the gasifier
20 is fed from the silo 80 via bed 31.
The oxygen of the second step of the process reaches
the cyclone 5 via the pipes 50, 51 or 52 respectively
placed at the inlet of the cyclone 5, in the cyclone 5 or
at the outlet of the cyclone 5. Oxygen also reaches the
secondary gasifier 501 via a pipe 53. In this
configuration for coproduction of hydrogen (at 90) and
electricity, the oxide oxidation reactor 3 feeds the
combustion reactor 2 with metal oxide particles in excess
relative to the stoichiometric quantity of oxygen and the
primary gasifier 20 with metal oxide particles in deficit
relative to the stoichiometric quantity of oxygen,
simultaneously and in a controlled manner. The locations
of the injection of oxygen for the second step of the
process are similar to those in figures 1 and 2.

WE CLAIM :
1. A method for effecting the energy conversion of solid fuels containing
carbon comprising :
reacting the solid fuels with oxygen provided by oxide particles to create
flue gases and unconverted compounds in a first oxide reduction reactor
having an exit, wherein the first oxide reduction reactor comprises a first
circulating fluidized bed;
oxidizing oxide particles in an oxide oxidation reactor, wherein the oxide
oxidation reactor comprises a second circulating fluidized bed;
providing flue gas and particles from the exit of the first oxide reduction
reactor directly to an inlet duct of a gas-solid separation cyclone, the
separation cyclone also having a roof, and an exit, wherein the separation
cyclone rotates the flue gases, oxide particles and unconverted
compounds to create increase residence time within the cyclone and to
separate out the oxide particles and convey the separated oxide particles
to the oxide oxidation reactor;
injecting oxygen into the separation cyclone of the first oxide reduction
reactor to convert unconverted compounds exiting the first oxide
reduction reactor, and

circulating the oxide particles between the oxide oxidation reactor and the
first oxide reduction reactor for conversion of the fuel and oxidization of
the oxide particles.
2. The method as claimed in claim 1, wherein the energy conversion of the
solid fuels is effected through combustion.
3. The method as claimed in claim 1, wherein the oxygen is injected into the
gas-solid separation cyclone that is operatively associated with the first
oxide reduction reactor.
4. The method as claimed in claim 1 wherein the oxygen is injected into the
inlet duct of the gas-solid separation cyclone that is operativeiy associated
with the first oxide reduction reactor.
5. The method as claimed in claim 1, wherein the oxygen is injected through
the roof of the gas-solid separation cyclone that is operativeiy associated
with the first oxide reduction reactor.
6. The method as claimed in claim 1, wherein the energy conversion of the
solid fuels is effected through gasification in a thermochemical cycle.

7. The method as claimed in claim 6, wherein the oxygen is injected through
the roof of a gas-solid separation cyclone that is operatively associated
with the first oxide reduction reactor.
8. The method as claimed in claim 7, wherein the oxygen is injected through
the roof substantially at the center of a gas-solid separation cyclone that
is operatively associated with the first oxide reduction reactor.
9. The method as claimed in claim 1, wherein the oxide particles are metal
oxides.
10. The method as claimed in claim 1, comprising a sixth step of providing a
second oxide reduction reactor having a circulating fluidized bed to
provide two channels for reaction of the fuel whereby oxide particles from
the oxide oxidation reactor circulates to both the first and second
reduction reactors, and a seventh step of injecting oxygen in the exit of
the second oxide reduction reactor.
11. A method for effecting the energy conversion of solid fuels containing
carbon comprising :
reacting the solid fuels with oxygen provided by oxide particles in a first
oxide reduction reactor having an exit, wherein the first oxide reduction
reactor comprises a first circulating fluidized bed;

oxidizing the oxide particles in an oxide oxidation reactor to create flue
gas and unconverted compounds, wherein the oxide oxidation reactor
comprises a second circulating fluidized bed;
providing a gas-solid separation cyclone at the exit of the first oxide
reduction reactor such that it receives the flue gas, unconverted
compounds and oxide particles and separates out the oxide particles and
provides increased residence time for reaction of the unconverted
compounds;
injecting oxygen into the first gas-solid separation cyclone to cause
increased conversion of unconverted compounds in the separation
cyclone, and
circulating oxide particles between the oxidation reactor and the first
oxide reduction reactor for conversion of the fuel and oxidization of the
oxide particles.


The invention relates to a method for effecting the energy conversion of solid
fuels containing carbon comprising : reacting the solid fuels with oxygen
provided by oxide particles to create flue gases and unconverted compounds in a
first oxide reduction reactor having an exit, wherein the first oxide reduction
reactor comprises a first circulating fluidized bed; oxidizing oxide particles in an
oxide oxidation reactor, wherein the oxide oxidation reactor comprises a second
circulating fluidized bed; providing flue gas and particles from the exit of the first
oxide reduction reactor directly to an inlet duct of a gas-solid separation cyclone,
the separation cyclone also having a roof, and an exit, wherein the separation
cyclone rotates the flue gases, oxide particles and unconverted compounds to
create increase residence time within the cyclone and to separate out the oxide
particles and convey the separated oxide particles to the oxide oxidation reactor;
injecting oxygen into the separation cyclone of the first oxide reduction reactor
to convert unconverted compounds exiting the first oxide reduction reactor, and
circulating the oxide particles between the oxide oxidation reactor and the first
oxide reduction reactor for conversion of the fuel and oxidization of the oxide
particles.

Documents:

03846-kolnp-2006 abstract.pdf

03846-kolnp-2006 claims.pdf

03846-kolnp-2006 description(complete).pdf

03846-kolnp-2006 drawings.pdf

03846-kolnp-2006 form-1.pdf

03846-kolnp-2006 form-2.pdf

03846-kolnp-2006 form-3.pdf

03846-kolnp-2006 form-5.pdf

03846-kolnp-2006 international publication.pdf

03846-kolnp-2006 international search authority report.pdf

03846-kolnp-2006 others.pdf

03846-kolnp-2006 pct request form.pdf

03846-kolnp-2006 priority document.pdf

03846-kolnp-2006-correspondence others-1.1.pdf

03846-kolnp-2006-correspondence-1.1.pdf

03846-kolnp-2006-form-26.pdf

03846-kolnp-2006-others.pdf

3846-KOLNP-2006-ABSTRACT 1.1.pdf

3846-KOLNP-2006-AMANDED CLAIMS.pdf

3846-KOLNP-2006-AMANDED PAGES OF SPECIFICATION.pdf

3846-kolnp-2006-correspondence.pdf

3846-KOLNP-2006-DESCRIPTION (COMPLETE) 1.1.pdf

3846-KOLNP-2006-DRAWINGS 1.1.pdf

3846-KOLNP-2006-EXAMINATION REPORT REPLY RECIEVED.pdf

3846-kolnp-2006-examination report.pdf

3846-KOLNP-2006-FORM 1-1.1.pdf

3846-kolnp-2006-form 18.1.pdf

3846-kolnp-2006-form 18.pdf

3846-KOLNP-2006-FORM 2-1.1.pdf

3846-kolnp-2006-form 26.pdf

3846-KOLNP-2006-FORM 3-1.1.pdf

3846-kolnp-2006-form 3.pdf

3846-kolnp-2006-form 5.pdf

3846-KOLNP-2006-FORM-27.pdf

3846-kolnp-2006-granted-abstract.pdf

3846-kolnp-2006-granted-claims.pdf

3846-kolnp-2006-granted-description (complete).pdf

3846-kolnp-2006-granted-drawings.pdf

3846-kolnp-2006-granted-form 1.pdf

3846-kolnp-2006-granted-form 2.pdf

3846-kolnp-2006-granted-specification.pdf

3846-KOLNP-2006-OTHERS 1.1.pdf

3846-kolnp-2006-others.pdf

3846-KOLNP-2006-PA.pdf

3846-KOLNP-2006-PETITION UNDER RULE 137.pdf

3846-kolnp-2006-reply to examination report.pdf

abstract-03846-kolnp-2006.jpg


Patent Number 249628
Indian Patent Application Number 3846/KOLNP/2006
PG Journal Number 44/2011
Publication Date 04-Nov-2011
Grant Date 31-Oct-2011
Date of Filing 20-Dec-2006
Name of Patentee ALSTOM TECHNOLOGY LTD.
Applicant Address BROWN BOVERI STRASSE 7, CH-5401 BADEN, SWITZERLAND
Inventors:
# Inventor's Name Inventor's Address
1 MORIN, JEAN-XAVIER 39, RUE DU CAS ROUGE MARCHANDON, F-45170 NEUVILLE AUX BOLS
2 BEAL, CORINNE 5, RUE VINCENT VAN GOGH, F-78960 VOISINS LE BRETONNEUX
PCT International Classification Number F23C 10/00
PCT International Application Number PCT/EP2005/052680
PCT International Filing date 2005-06-09
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 04/51,263 2004-06-11 France