METHOD AND DEVICE FOR HIGH-CAPACITY ENTRAINED FLOW GASIFIER

METHODE ET DISPOSITIF POUR REACTEUR A LIT ENTRAINE A GRAND RENDEMENT

English Abstract

The instant disclosure seeks to improve the availability of entrained flow
reactors,
for gasifying pulzerized fuel dusts, avoiding mere duplication of each lock
hopper and
dosing system. In particular, the expenditure for a full duplication of lock
hoppers and
dosing systems is avoided. In case one lock hopper and dosing systems fails,
all burners
are still supplied by the remaining lock hoppers and dosing systems; thus, an
ongoing
operation of all burners of the gasifier without crooked burning is performed.
The method
involves assigning each gasification burner to a set of locking and dosing
systems with a
set of delivered flows. Pressure lines are arranged between one of the
basification burners
and a locking and a dosing system. The gasification burners have supplies,
where each
supply of a respective gasification burner is connected to one of the locking
and dosing
systems by pressure lines.

French Abstract

La présente invention cherche à améliorer la disponibilité de réacteurs à lit entraîné pour gazéifier des poussières de combustible pulvérisé, en évitant la simple duplication de chaque trémie à sas et système de dosage. En particulier, la dépense inhérente à une duplication complète des trémies à sas et des systèmes de dosage est évitée. En cas de défaillance d'une trémie à sas et d'un système de dosage, tous les brûleurs sont toujours alimentés par les trémies à sas et les systèmes de dosage restants; on obtient ainsi un fonctionnement continu de tous les brûleurs du gazéifieur sans altération du brûlage. Le procédé consiste à assigner chaque brûleur de gazéification à un jeu de systèmes de sas et de dosage avec un ensemble de flux d'alimentation. Des conduites sous pression sont disposées entre un des brûleurs de gazéification et un système de sas et de dosage. Les brûleurs de gazéification comportent des alimentations, chaque alimentation d'un brûleur de gazéification respectif étant raccordée à l'un des systèmes de sas et de dosage par des conduites de pression.

Claims

CLAIMS:
1. An apparatus for gasifying combustible dusts comprising hard coal,
lignite, petroleum
coke, or solid grindable residues, and slurries, comprising:
an entrained gasification reactor for gasifying the combustible dusts at
temperatures
ranging from 1200 to 1900 degrees C and pressures of up to 80 bar;
wherein said gasification reactor comprises a plurality of gasification
burners, each burner
having an individual feed port;
wherein each gasification burner comprises a plurality of supply ports
connected to said
feed port;
a plurality of lock hopper and dosing systems arranged to supply dust or
slurries to the
gasification burners; and
a plurality of supply lines corresponding in number with said plurality of
supply ports
leading from each lock hopper and dosing system to said supply ports, and
configured to provide
dust or slurries to each feed port of every single burner.
2. The apparatus as set forth in claim 1, wherein a number of the plurality
of lock hopper and
dosing systems is fewer than the number of the plurality of gasification
burners.
3. The apparatus as set forth in claim 2, wherein there are three
gasification burners and two
lock hopper and dosing systems.
4. The apparatus as set forth in claim 3, wherein each gasification burner
is simultaneously
supplied from two lock hopper and dosing systems through at least two supply
lines, each of these
two supply lines being associated with a different lock hopper and dosing
system.
5. The apparatus as set forth in claim 1, wherein said plurality of lock
hopper and dosing
systems are configured to simultaneously supply dust or slurries to feed at
least two of said
plurality of gasification burners.
6. A reactor for the gasification of pulverized fuel from solid fuels such
as bituminous coals,
lignite coals, and their cokes, petroleum cokes, cokes from peat or biomass,
in entrained flow, with
an oxidizing medium containing free oxygen at temperatures between 1,200 and
1,900 degrees C
and at pressures between atmospheric pressure and 80 bar, into a crude
synthesis gas and slag, the
reactor comprising:
a reactor head;
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an ignition and pilot burner disposed at said head of the reactor;
a plurality of equal gasification burners disposed at said head of the
reactor;
a plurality of lock hoppers and dosing systems arranged to supply said
pulverized fuels to
said plurality of equal gasification burners;
individual transport lines assigned to each gasification burner, said
individual transport
lines connecting and feeding said pulverized fuels from said lock hopper and
dosing systems to the
respective gasification burner;
wherein every single gasification burner is connected and fed by at least two
different lock
hoppers and dosing systems; and
a measuring system configured to measure and regulate amounts of pulverized
fuel and
oxygen flowing in each of said plurality of equal gasification burners, said
measuring system
controlling the overall total amounts of pulverized fuel and oxygen flowing in
the reactor.
7. The reactor as in claim 6, wherein said plurality of equal gasification
burners comprise at
least three gasification burners and wherein said plurality of lock hoppers
comprise at least three
lock hoppers and dosing systems, wherein each gasification burner of said
plurality of equal
gasification burners is connected and fed with pulverized fuel over two burner
individual transport
lines with every single one of said three lock hoppers and dosing systems.
8. The reactor as in claim 6, wherein said plurality of equal gasification
burners comprise
three gasification burners and said plurality of lock hoppers and dosing
systems comprise at least
two lock hoppers and dosing systems, wherein each gasification burner is
connected and fed with
pulverized fuel over two burner individual transport lines with every single
of said two lock
hoppers and dosing systems.
9. The apparatus as in claim 4, wherein said plurality of lock hopper and
dosing systems are
configured and arranged such that the burners will continue to operate
steadily upon failure of one
of them, wherein each of said two lock hopper and dosing systems are coupled
to each burner in a
redundant manner so that redundancy is provided in the event of a system
failure.
10. The reactor as in claim 6, wherein said plurality of lock hopper and
dosing systems are
configured and arranged such that the burners will continue to operate
steadily upon failure of one
of them, wherein each of said at least two lock hopper and dosing systems are
coupled to each of
said plurality of equal gasification burners in a redundant manner so that
redundancy is provided in
the event of a system failure.
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11. The apparatus as in claim 1, wherein a plurality of the gasification
burners are supplied
uniformly with combustible dust.
12. The reactor as in claim 6, wherein a plurality of the gasification
burners are supplied
uniformly with combustible dust.
13. The apparatus as in claim 1, wherein all of the gasification burners
are supplied uniformly
with combustible dust.
14. The reactor as in claim 6, wherein all of the gasification burners are
supplied uniformly
with combustible dust.
15. The apparatus as in claim 1, wherein each of said plurality of
gasification burners is
coupled to said plurality of lock hopper and dosing systems such that said
plurality of gasification
burners are configured and arranged to prevent crooked burning in the
gasification reactor.
16. The reactor as in claim 6, wherein each of said plurality of
gasification burners is coupled
to said plurality of lock hopper and dosing systems such that said plurality
of gasification burners
are configured and arranged to prevent crooked burning in the gasification
reactor.
17. The apparatus as in claim 1, further comprising at least one metering
system coupled to
said entrained gasification reactor.
18. The apparatus as in claim 17, wherein said at least one metering system
comprises at least
one bunker, at least two pressurized sluices, and at least one metering tank,
wherein an output of
said metering system is coupled to said entrained gasification reactor.
19. The reactor as in claim 6, wherein said measuring system further
comprises at least one
bunker, at least two pressurized sluices, and at least one metering tank,
wherein an output of said
metering system is coupled to said entrained gasification reactor.
20. The reactor as in claim 19, further comprising at least one fluidizing
gas line which leads
into said at least one metering tank from below, and which provides for
fluidizing the fuel.
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Description

CA 02562618 2006-10-05
Method and Device for High-capacity Entrained Flow Gasifier
Field of the Invention
The invention relates to a method for entrained flow gasification with very
high
capacity that can be used for supplying Large Scale syntheses with synthesis
gas. The
invention enables conversion of combustibles refined into pulverized
combustible dusts,
such as hard coal and lignite, petroleum coke, solid grindable residues but
also solid-
liquid suspensions, so-called slurries, into synthesis gas. The combustible is
thereby
converted through partial oxidation into CO- and H2-containing gases at
temperatures
ranging from 1,200 to 1,900 C using a gasification agent containing free
oxygen at
pressures of up to 80 bar. This occurs in a gasification reactor distinguished
by a
multiple burner array and by a cooled gasification chamber.
Background of the Invention
In gas production techniques, the autothermal entrained flow gasification of
solid, liquid and gaseous combustibles has been known for many years. For
reasons of
synthesis gas quality, the ratio of combustible to oxygen-containing
gasification agents
is chosen such that higher carbon compounds are completely cleaved into
synthesis gas
components, such as CO and H2, and such that the inorganic constituents are
discharged
in the form of a molten slag.
According to different systems well known in the art, gasification gas and
molten slag can be discharged separately or together from the reaction chamber
of the
gasification apparatus, as shown in DE 197 18 131 Al. Systems provided with a
refractory lining or cooled systems are known for the internal confinement of
the
reaction chamber structure of the gasification system.
EP 0677 567 B1 and WO 96/17904 show a method in which the gasification
chamber is confined by a refractory lining. This has the drawback that the
refractory
masonry is loosened by the liquid slag formed during gasification, which leads
to rapid
wear and high repair costs. This wear process increases with increasing ash
content.
Thus such gasification systems have a limited service life before replacing
the lining.
Also, the gasification temperature and the ash content of the fuel are
limited; see
C. Higman and M. van der Burgt, "Gasification", Verlag Elsevier, USA, 2003. A
quenching or cooling system is also described, with which the hot gasification
gas and
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CA 02562618 2006-10-05
the liquid slag are carried off together through a conduit that begins at the
bottom of the
reaction chamber, and are fed into a water bath. This joint discharge of
gasification gas
and slag can lead to plugging of the conduit and thus to limitation of
availability.
DE 3534015 Al shows a method in which the gasification media, powdered fuel
and oxidizing medium containing oxygen, are introduced into the reaction
chamber symmetrically through multiple burners in such a way that the flames
are
mutually diverted. The gasification gas loaded with powdered dust flows upward
and
the slag flows downward into a slag-cooling system. As a rule, there is a
device above
the gasification chamber for indirect cooling utilizing the waste heat.
However, because
of entrained liquid slag particles there is the danger of deposition and
coating of heat
exchanger surfaces, which hinders heat transfer and may lead to plugging of
the pipe
system and/or erosion. The danger of plugging is counteracted by taking away
the hot
crude gas with a circulated cooling gas.
C. Higman and M. van der Burgt in "Gasification", page 124, Verlag Elsevier
2003, describe a method in which the hot gasification gas leaves the gasifier
together
with the liquid slag and directly enters a waste heat boiler positioned
perpendicularly
below it, in which the crude gas and the slag are cooled with utilization of
the waste heat
to produce steam. The slag is collected in a water bath, while the cooled
crude gas
leaves the waste heat boiler from the side. A series of drawbacks detract from
the
advantage of waste heat recovery by this system. To be mentioned here in
particular is
the formation of deposits on the heat exchanger tubes, which lead to hindrance
of heat
transfer and to corrosion and erosion, and thus to lack of availability.
CN 200 4200 200 7.1 describes a "Solid Pulverized Fuel Gasifier", in which the
powdered coal is fed in pneumatically and gasification gas and liquefied slag
are
introduced into a water bath through a central pipe for further cooling. This
central
discharge in the central pipe mentioned is susceptible to plugging that
interferes with the
overall operation, and reduces the availability of the entire system.
The capacity of the various gasification technologies mentioned is limited to
about 500 MW, which is attributable in particular to the fuel infeed to the
gasification
reactor.
It is the purpose of this invention, proceeding from this state of the art, to
provide a gasification method that permits maximum capacities of 1,000 to
1,500 MW
with reliable and safe operation.
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CA 02562618 2012-08-22
Summary of the Invention
A preferred embodiment of the method in accordance with the invention
includes the steps of: supplying the combustible dusts to multiple identically
engaged
metering systems that feed the dusts, through transport pipes to multiple
gasification
burners located at the head of a reactor, each gasification burner being
associated with at
least two lock hopper and dosing systems having a plurality of supply flows;
igniting
multiple dust burners with oxygen infeed in the head of the gasification
reactor by
ignition and pilot burners; determining the quantities of the dusts and oxygen
fed to the
dust burners, with the overall total of all amounts of dust and oxygen
supplied being
determined, and with a regulating mechanism assuring that the oxygen ratio
neither
exceeds nor falls below a ratio of 0.35 to 0.65, regardless of the
distribution of dust and
oxygen to the burners; converting the dusts in the gasification reactor at
temperatures
between 1,200 and 1,900 C and at pressures between atmospheric pressure and 80
bar,
into a crude synthesis gas and slag; cooling down the hot crude gas at 1,200
to 1,900 C
together with the slag to the condensation point at temperatures between 180 C
and
240 C in a quenching cooler by injecting water; and feeding the cooled crude
gas to
further treatment stages such as water scrubbing, partial condensation, or
catalytic
processes.
A preferred apparatus in accordance with the invention is characterized in
that
supply lines are interposed between the gasification burners having feed ports
and the
lock hopper and dosing systems, supply lines leading from each lock hopper and
dosing
system to the feed port of every single gasification burner.
In high-performance entrained flow reactors, it is necessary to arrange a
plurality
of gasification burners if one wants to achieve secure conversion of the
combustible. In
order to ensure start up and secure operation of such reactors, a central
ignition and pilot
burner is disposed that is surrounded by 3 dust burners symmetrically spaced
120 apart
from each other. In order to allow the introduction of large amounts of
combustible
dust, of for example 100-400 t/h, into the gasification reactor operated under
pressure, a
plurality of lock hopper and dosing systems are arranged for supplying dust to
the
gasification burners. It is possible to associate a lock hopper and dosing
system with
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CA 02562618 2006-10-05
each gasification burner. Most preferably each lock hopper and dosing system
is
connected to a plurality of gasification burners in order to increase
reliability.
The solution of the invention provides a method in which at least two lock
hopper and dosing systems are associated with each gasification burner. Supply
lines
lead from each lock hopper and dosing system to the feed ports in the various
gasification burners. There may be less lock hopper and dosing systems than
gasification burners. Two lock hopper and dosing systems may for example
supply
combustible to three gasification burners through lines. Furthermore, the
supply lines of
three lock hopper and dosing systems may lead to different gasification
burners so that
three gasification burners having each three feed ports may be provided, each
feed port
being supplied with combustible from another lock hopper and dosing system.
The
combustible dust of each lock hopper and dosing system is distributed evenly
to the
gasification burners through the respective supply lines. Providing a
plurality of lock
hopper and dosing systems offers the advantage that the burners will continue
to operate
steadily upon failure of one of them.
When each gasification burner is supplied through at least two supply lines,
one
supply line is led from each lock hopper and dosing system to each burner so
that
redundancy is provided in the event of a system failure.
The solution to the invention has the advantage that all the gasification
burners
are supplied uniformly and reliably with combustible dust. In this manner, it
is possible
to mix combustible dusts from diverse lock hopper and dosing systems of the
large
plants in the gasification burner.
Brief Description of the Drawings
The three following examples and the three Figures are intended to provide a
better understanding of the invention. In said Figures:
Figure 1: shows an example in which each gasification burner is
associated with
one lock hopper and dosing system.
Figure 2: shows an example in which three gasification burners are
associated with
three lock hoppers and dosing systems, whereas each dust burner has one
feed line from each of the three lock hoppers and dosing systems.
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CA 02562618 2006-10-05
Figure 3: shows an example in which three gasification burners are
associated with
two lock hoppers and dosing systems, whereas each gasification burner
has one feed line from each of the two lock hoppers and dosing systems.
Detailed Description of the Invention
Figure 1 shows an example in which each lock hopper and dosing system 1, 2, 3
is associated with one gasification burner 4, 5, 6. The objective is to feed a
gasification
reactor for entrained flow gasification of carbon dust with a gross input of
1,000 MW
with the 180 Mg/h carbon dust needed for this purpose. For this purpose, there
are
arranged three lock hopper and dosing systems 1, 2, 3 (Fig. 1), each supplying
a
gasification burner 4, 5, 6 through the supply ports 4.1 through 6.3 thereof
with 60 Mg/h
combustible dust through three supply lines 1.1 through 3.3 with a feed
capacity of 20
Mg/h. The capacity of each dust supply line 1.1 through 3.3. can be set in the
range
from 15-30 Mg/h. The three dust supply lines 1.1 through 3.3 of each lock
hopper and
dosing system 1, 2, 3 thereby end in a gasification burner 4, 5, 6 supplying
it with the 60
Mg/h carbon dust mentioned. All the three lock hopper and dosing systems 1, 2,
3 must
be in operation. Operation with two of the three gasification burners 4, 5, 6
results in
unacceptable crooked burning in the gasification reactor. In the event of a
failure of only
one of the supply lines 1.1 through 3.3, the burner 4, 5, 6 of concern may
also be
operated for a limited time with two supply lines.
Figure 2 shows an example in which three lock hoppers and dosing systems 1,
2, 3 are associated with all three gasification burners 4, 5, 6. The objective
is the same
as in Figure 1. However, the three supply pipes 1.1 through 3.3 of each lock
hopper and
dosing system 1, 2, 3 are not connected to one gasification burner, but with
all the three.
Upon failure of one lock hopper and dosing system 1, 2, 3 each gasification
burner 4, 5,
6 may also be supplied for a limited time from the two still operating lock
hopper and
dosing systems 1, 2, 3.
Figure 3 shows two lock hopper and dosing systems 1, 2 which are connected to
three gasification burners 4, 5, 6. The objective is to supply a gasification
reactor for
entrained flow gasification of carbon dust having an output of 500 MW with the
90
Mg/h carbon dust needed for this purpose. For this purpose, two lock hopper
and dosing
systems 1,2 each having a capacity of 45 Mg/h, are arranged, each of the three
supply
lines 1.1 through 2.3 having an output of 15 Mg/h. Each gasification burner 4,
5, 6 is
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CA 02562618 2006-10-05
supplied from two supply lines 1.1 through 2.3 originating from a respective
one of the
lock hopper and dosing systems 1, 2. As a result, two lock hopper and dosing
systems
1, 2 can be utilized for middle-performance gasification reactors having three
gasification burners 4, 5, 6.
6

Representative Drawing