U.S. patent application number 12/058087 was filed with the patent office on 2008-10-23 for gasification reactor.
Invention is credited to Thomas Paul Von Kossak-Glowczewski.
Application Number | 20080256860 12/058087 |
Document ID | / |
Family ID | 38542646 |
Filed Date | 2008-10-23 |
United States Patent
Application |
20080256860 |
Kind Code |
A1 |
Von Kossak-Glowczewski; Thomas
Paul |
October 23, 2008 |
GASIFICATION REACTOR
Abstract
The invention is directed to a gasification reactor comprising a
pressure shell, a reaction zone partly bounded by a vertically
oriented tubular membrane wall, said wall being provided with one
or more openings and wherein attached to the wall and above the
opening a slag deflector is present. The invention is also directed
to a process to prepare a mixture of hydrogen and carbon monoxide
by gasification of a solid or liquid feedstock comprising between
15 and 50 wt % ash in a gasification reactor, wherein the feedstock
and an oxygen containing gas and an optional moderator gas are
provided to a burner as provided in an opening of the reactor and
wherein the gasification in the reaction zone is carried out at a
temperature in the range from 1200 to 1800.degree. C. and at a
pressure in the range from between 30 and 100 bar.
Inventors: |
Von Kossak-Glowczewski; Thomas
Paul; (Gummersbach, DE) |
Correspondence
Address: |
SHELL OIL COMPANY
P O BOX 2463
HOUSTON
TX
772522463
US
|
Family ID: |
38542646 |
Appl. No.: |
12/058087 |
Filed: |
March 28, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60910095 |
Apr 4, 2007 |
|
|
|
Current U.S.
Class: |
48/201 ;
48/72 |
Current CPC
Class: |
C10J 2300/0959 20130101;
C10J 3/76 20130101; C10J 3/485 20130101; C10J 2200/152 20130101;
C10J 2300/1846 20130101; C10J 2200/09 20130101; C10J 2300/1223
20130101; C10J 3/845 20130101; C10J 2300/093 20130101; C10K 1/101
20130101; C10J 3/526 20130101; C10J 2300/1634 20130101 |
Class at
Publication: |
48/201 ;
48/72 |
International
Class: |
C10K 3/06 20060101
C10K003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2007 |
EP |
07105317.7 |
Claims
1. A gasification reactor comprising a pressure shell, a reaction
zone partly bounded by a vertically oriented tubular membrane wall,
said wall being provided with one or more openings and wherein
attached to the wall and above said opening a slag deflector is
present.
2. A gasification reactor according to claim 1, wherein the slag
deflector is a conduit attached to the membrane wall provided with
an inlet end for a cooling medium and an outlet end for used
cooling medium and wherein said conduit has a part located at a
higher elevation above the opening and lower parts of the conduit
extending side ways, such that in use at least part of the
downwardly flowing slag is deflected away from the opening.
3. A gasification reactor according to claim 1, wherein 2 or more
deflectors are positioned above the opening and wherein each
deflector is vertically spaced away from the adjacent
deflector.
4. A gasification reactor according to claim 2, wherein the
deflector comprises parts extending downwards to make an angle of
between 90 and 140.degree..
5. A gasification reactor according to claim 1, wherein in the
opening a start-up burner and or an ignitor is present.
6. A gasification reactor according to claim 1, wherein in the
opening a flame detector is present.
7. A gasification reactor according to claim 1, wherein in the
opening a burner is present for performing the gasification of an
ash containing solid or liquid carbonaceous feedstock.
8. A gasification reactor according to claim 7, wherein the burner
is positioned in the opening via a burner muffle.
9. A gasification reactor according to claim 1, wherein the
deflector is made from a low alloy steel with a Cr content of up to
5 wt % or a high alloy steel with a Cr content above 15 wt %.
10. A gasification reactor according to claim 1, wherein the
reaction zone has an outlet for a product gas at its upper end and
an outlet for slag at its lower end.
11. A process to prepare a mixture of hydrogen and carbon monoxide
by gasification of a solid or liquid feedstock comprising between
15 and 50 wt % ash in a gasification reactor according to claim 1,
wherein the feedstock and an oxygen containing gas and an optional
moderator gas are provided to a burner as provided in an opening of
the reactor and wherein the gasification in reaction zone is
carried out at a temperature in the range from 1200 to 1800.degree.
C. and at a pressure in the range from between 30 and 100 bar.
Description
[0001] This application claims the benefit of European Application
No. 07105317.7 filed Mar. 30, 2007 and U.S. Provisional Application
No. 60/910,095 filed Apr. 4, 2007.
FIELD OF THE INVENTION
[0002] The invention is directed to a gasification reactor
comprising a pressure shell and a reaction zone partly bounded by a
vertically oriented tubular membrane wall. The membrane wall is
provided with one or more openings.
BACKGROUND OF THE INVENTION
[0003] Such a gasification reactor is described in U.S. Pat. No.
4,202,672. This publication describes a coal gasification reactor
provided with a pressure shell, a reaction zone and a membrane
wall, which partly defines the reaction zone. The tubular shaped
membrane wall comprises interconnected conduits in which
evaporating cooling water is present.
[0004] In U.S. Pat. No. 4,959,080 a coal gasification process is
described which may be performed in a gasification reactor as
above. This publication described that a layer of slag will form on
the membrane wall during gasification of coal. This layer of slag
will flow downwards along the inner side of the membrane wall.
[0005] The Shell Coal Gasification Process also makes use of a
gasification reactor comprising a pressure shell and a membrane
walled reaction zone according to "Gasification" by Christofer
Higman and Maarten van der Burgt, 2003, Elsevier Science,
Burlington Mass., pages 118-120. According to this publication the
Shell Coal Gasification Process is typically performed at
1500.degree. C. and at a pressure of between 30 and 40 bar. The
horizontal burners are placed in openings in the membrane wall.
[0006] Applicants have successfully performed the Shell Coal
Gasification Process using different types of feedstock. However
when processing feedstocks having a substantial high ash content,
more in particular when processing such a feedstock at higher
pressures, it is found that the operation of the process becomes
more difficult due to ingress of slag into the openings in the
membrane wall. Slag ingress may cause that the area forming the
opening for the burner is damaged.
[0007] It would be advantageous to provide a gasification reactor,
which is more suited to process feedstocks having a high ash
content.
SUMMARY OF THE INVENTION
[0008] The invention provides a gasification reactor comprising a
pressure shell, a reaction zone partly bounded by a vertically
oriented tubular membrane wall, said wall being provided with one
or more openings and wherein attached to the wall and above said
opening a slag deflector is present.
[0009] Applicants have found that by having a slag deflector above
the openings in the membrane wall less or even no slag ingress
occurs resulting in less damage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view of a gasification reactor
according to the invention.
[0011] FIG. 2 is a more detailed view of the reactor of FIG. 1
illustrating a burner opening in the membrane wall and represents
the cross-sectional view CC' of the same detail as shown in FIG.
3.
[0012] FIG. 3 is a more detailed view of the reactor of FIG. 1
illustrating a burner opening in the membrane wall.
[0013] FIGS. 3a and 3b are the cross-sectional views BB' and AA'
respectively as shown in FIG. 3.
[0014] FIG. 4 shows more detailed view of the reactor of FIG. 1
illustrating a start-up burner opening in the membrane wall.
[0015] FIG. 4a is the cross-sectional view DD' of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In a preferred embodiment, the present invention provides a
slag deflector above one or more openings in a tubular membrane
wall of a gasification reactor. The upper end of the slag deflector
may be positioned between 0.1 and 3 times the width of the opening
above the upper end of said opening. The slag deflector may be a
rim attached to the membrane wall. The rim may be provided with a
refractory coating. The deflector may be a conduit attached to the
membrane wall provided with an inlet end for a cooling medium and
an outlet end for used cooling medium. Said conduit may have a part
located at a higher elevation above the opening and lower parts of
the conduit extending side ways, such that in use at least part of
the downwardly flowing slag is deflected away from the opening. The
conduit may be provided with a refractory coating.
[0017] The slag deflector may be made from a low alloy steel with a
Cr content up to 5 wt % or a high alloy steel with Cr content above
15 wt %.
[0018] Two or more deflectors may be positioned above the opening,
wherein each deflector is vertically spaced away from the adjacent
deflector. In a further embodiment two deflectors are positioned
above the opening. The second deflector may be positioned between
0.5 and 3 times the width of the opening above the upper end of the
first deflector. Such an embodiment having more than one deflector
is especially suitable above the opening in the membrane wall in
which a burner is provided. The deflector above such a burner
opening may be designed such that part of the slag is directed away
from the lower positioned opening and part of the slag retains it
vertically downward flow path. This results that less slag comes
near the opening but at the same time results in a sufficient flow
of slag being maintained near said opening to provide the necessary
isolation function.
[0019] In case the opening in the membrane wall concerns an opening
for equipment, which will only be used during start-up, a more
robust deflection of the slag is advantageous, because slag may
accumulate during normal operation in such openings and solidify.
Examples of equipment, which may be positioned in such openings
during start-up, are a start-up burner, an igniter and means to
detect a flame, e.g. a flame eye. In case the gasification reactor
is required to be shut down and restarted for whatever reason, this
hard slag needs to be removed mechanically from these openings and
the start-up burner and its ignitor need to be disassembled for
this purpose. This is found to be a time consuming operation, and
it would therefore be advantageous to avoid it. Applicants have now
found that by positioning a slag deflector above these openings,
which deflect all the slag during normal operation, ingress and
solidification of slag in said openings is avoided.
[0020] Other advantages and preferred embodiments will be discussed
below making use of FIGS. 1-4.
[0021] FIG. 1 shows a gasification reactor having a vertically
oriented tubular pressure shell 1, a membrane wall 3 and a reaction
zone 2. Part 3a of the membrane wall 3 is tubular shaped. The
membrane wall 3 is composed of vertical conduits through which
water flows. Water is supplied to the membrane wall via supply line
4 to a common distributor 5. The used cooling water, typically in
the form of a water/steam mixture is discharged from the reactor
via common header 6 and discharge line 7. The reactor is further
provided with a quench gas supply 8. The invention is especially
suited for a reactor, wherein the reaction zone 2 has an outlet 9
for a product gas at its upper end and a discharge outlet 10 for
slag at its lower end. Product gas comprises a mixture of hydrogen
and carbon monoxide as prepared in the gasification reactor. Two
diametrically positioned openings 13 are shown in the membrane wall
3. In these openings 13, two diametrically placed burners 14 are
placed. The reactor may comprise, for example, two or more pairs of
such burners at the same elevation or alternatively at different
elevations. Burner 14 is suited for performing the gasification of
an ash containing solid or liquid carbonaceous feedstock. Suitable
burners for a solid carbonaceous feedstock, suitably coal, are for
example described in U.S. Pat. No. 4,523,529 and U.S. Pat. No.
4,510,874. The burners are fed by a coal supply line 11 and a
supply line 12 for oxygen. Other openings, not shown in FIG. 1 for
clarity reasons, may be provided in the membrane wall 3 for
start-up burners, igniters and flame eyes. Above opening 13 a slag
deflector 15 is shown.
[0022] FIG. 2 shows a detail of FIG. 1 showing opening 13 in the
tubular part 3a of the membrane wall 3. In this Figure two
deflectors 15a and 15b for deflecting slag 19 are shown, spaced
away from each other and above opening 13. In opening 13 a burner
14 is present, in which burner 14 and its flame the gasification
reaction takes place. The opening 13 is further provided with a
muffle 16. Muffle 16 comprises several vertically oriented,
concentric and interconnected rings 17. Preferably at least 1 or
more and more preferably all rings 17 are conduits having an inlet
for a cooling medium via lines 20 and an outlet for used cooling
medium via lines 22. The rings 17 are preferably made from a low
alloy steel with a Cr content up to 5 wt % or a high alloy steel
with Cr content above 15 wt %. The muffle 16 preferably extends
some distance into the reaction zone 2 as shown to create a slag
gutter 18 which allows the remaining slag 19a as its flows towards
the opening 13 to flow around the opening 13 and avoid ingress of
the slag 19a into opening 13.
[0023] FIG. 2 also shows a refractory coating 21 as present on the
membrane wall 3a. To keep the coating 21 fixed to said wall 3a
studs 23 are connected to wall 3a.
[0024] Lines 20 are fluidly connected to cooling medium, typically
water, distributor 24 and a common, typically water/steam mixture,
header 25 respectively. The rings 17 are preferably welded
together.
[0025] FIGS. 3, 3a and 3b shows a view of the reactor section of
membrane wall 3a shown in FIG. 2 as viewed from the centre of
reaction zone 2. The reference numbers refer to the same elements.
As shown deflector 15a has an inlet 27 for a cooling medium and an
outlet 26 for used cooling medium. Deflector 15b is also provided
with an inlet 29 for a cooling medium and an outlet 28 for used
cooling medium. The deflectors 15a and 15b are provided with lower
parts extending downwards making an angle .alpha. of between 90 and
140.degree. when viewed in a horizontal direction, as shown in FIG.
3.
[0026] FIG. 4 shows a preferred slag deflector 30 for use above an
opening for equipment, which will only be used during start-up as
discussed above. In FIGS. 4 and 4a a start-up burner 37 and an
ignitor 36 are shown. Slag deflector 30 is made of two parallel
conduits, 31 and 32 which extend more into the reaction zone 2 than
the deflectors 15a and 15b of FIG. 2. This will result in that
essentially all the slag 38 is deflected away from opening 33
during normal operation. Deflector 30 is provided with inlet 34 for
a cooling medium and an outlet 35 for used cooling medium.
[0027] The cooling medium, preferably cooling water as supplied to
the muffle 16 or to the above-illustrated deflector embodiments may
be from the same source as the cooling water supplied to the
membrane wall via 4. It can be also from a different source, which
may have a lower water temperature and/or a different pressure.
[0028] Applicants found that the gasification reactor according to
the invention is especially suited to prepare a mixture of carbon
monoxide and hydrogen from a feedstock having an ash content of
between 6 and 50 wt %. It has been found that the reactor according
to the invention is especially suited for feeds having a high ash
content, higher than 15 wt %, or even higher than 20 wt %. For
economic reasons the ash content may be below 40 wt %. Feeds having
an even higher ash content are preferably blended with lower ash
content feeds in order to bring the total ash content of the
combined feed to a value within the above ranges. Suited ash
containing solid carbonaceous feeds are coal and biomass, for
example wood and agricultural wastes. Suited ash containing liquid
carbonaceous feeds are tar sand fractions and other bituminous
oils. A particularly suited feedstock is coal having the ash
contents as described above.
[0029] The gasification, or also referred to as partial oxidation,
of the feedstock is carried out in the presence of an oxygen
containing gas and possibly a moderator gas. A suited moderator gas
is steam. Solid carbonaceous feedstocks may be provided to the
burner as a mixture of solid particles in a carrier gas. Suited
carrier gasses are nitrogen and carbon dioxide. The gasification in
reaction zone 2 is carried out at a temperature in the range from
1200 to 1800.degree. C. and at a pressure in the range from 1 to
200 bar, between 30 and 100 bar or at a pressure of above 35 bar
and below 70 bar.
* * * * *