CA1118600A - Two-stage coal gasification process and apparatus - Google Patents
Two-stage coal gasification process and apparatusInfo
- Publication number
- CA1118600A CA1118600A CA000322023A CA322023A CA1118600A CA 1118600 A CA1118600 A CA 1118600A CA 000322023 A CA000322023 A CA 000322023A CA 322023 A CA322023 A CA 322023A CA 1118600 A CA1118600 A CA 1118600A
- Authority
- CA
- Canada
- Prior art keywords
- gasification
- fixed bed
- fuel
- gasifying agent
- slag
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Gasification And Melting Of Waste (AREA)
Abstract
ABSTRACT
A coal gasification process and apparatus therefore in which means are provided for supplying fuel to and maintaining a fixed fuel bed in the upper region of a reactor vessel, supplying additional fuel together with a gasifying agent to initiate and maintain gasification in an entrained stage located in the lower region of the vessel, the gasification products from the entrained stage passing up through and gasifying fuel in the fixed bed, the slag from the fixed bed passing downwards to mix with slag from the entrained stage and exits via a slag tap to a slag quench system located below the reactor vessel.
The fixed bed may be maintained in the upper region of the vessel by a grate which extends across the vessel. The grate may be cooled by the circulation of an appropriate coolant through the elements forming the grate.
A coal gasification process and apparatus therefore in which means are provided for supplying fuel to and maintaining a fixed fuel bed in the upper region of a reactor vessel, supplying additional fuel together with a gasifying agent to initiate and maintain gasification in an entrained stage located in the lower region of the vessel, the gasification products from the entrained stage passing up through and gasifying fuel in the fixed bed, the slag from the fixed bed passing downwards to mix with slag from the entrained stage and exits via a slag tap to a slag quench system located below the reactor vessel.
The fixed bed may be maintained in the upper region of the vessel by a grate which extends across the vessel. The grate may be cooled by the circulation of an appropriate coolant through the elements forming the grate.
Description
Improvements in or relatin~ to Coal Gasification Plant ~his invention relates to coal gasification plant, and more particularly to an improved and modified form of slagging gasifier said slagging gasifier being plants of the kind (hereinafter referred to as the kind specified) in which coal, or other carbonaceous fuel, is introduced into the top of a column-like gasifying vessel and is gasified under high pressure and temperature by means of oyygen and steam introduced near the fuel bed through tuyeres. ~he residual ash collects as a molten slag and iron in the hearth of the gasifier vessel from which it is discharged (commonly known as slag-tapping) downwardly through a slag tap outlet or orifice in the hearth into water contained in a quenching chamber. Usually, a pool of molten slag and iron is maintained in the hearth by directing hot combustion products from a burner located beneath the slag tap orifice up the tap orifice to retain the pool of slag and iron in the hearth, the tapping of the molten slag and iron being initiated and controlled by stopping or reducing the burner output and reducing the pressure in the quenching chamber by controlled venting to atmosphere thr~ugh its venting system so as to produce a differential pressure between the quenching chamber and the gasifier vessel.
.
Examples of such slagging gasifier plant are those disclosed in 7Jnited Kin.gdom Patent Specification ~o. 977,122 and the Gas Council Research Co~77n;cations ~o's GC 50 and GC 112.
t~
6~0 A slagging gasifier plant of the kind specified represents slagging gasification in its si_plest form and is a form most appropriate to the fixed bed gasification of "lump" coal (nominally 2" - ~") at high pressure in steam and oxygen. It is particularly suited for the production of substitute natural gas (S~G) and synthesis gas.
~he gasifier has an output two or three times greater than the well known c~nd con~entional grate-type gasifier; has a lower steam oonsumption; produces less aqueous liquor; has a greater thermal efficiency and, on the less reactive low fusion point ash coals, has a lower oxygen consumption. ~either the slagging or the grate-type gasifiers can operate with a coal feed which contains a high proportion of coal fines although the slagging gasifier will accommodate the injection of fine coal or char at the tuyeres up to about 10% of the total fuel supply. Future coal supplies may consist of even more fines than those of today and the ability to consume a total mine output will be an important requirement for conservation of resources.
S~G plants in the USA and those that might be built later in Europe are expected to have capacities of 250 MMSCFD and will require about 5~ million tons of coal per year which will come from one or more mines dedicated to the plant. Strip m;n;~g produces a minimum of 2~/o material below ~" in size, mechanised deep coal m;n;ng produces as much as 40~/o while figures as high as 60Yo have been quoted for strip mining of brown coal in Germany. lhe ability to gasify fLne coal therefore could become a major ;f not an essential requirement of future gasification systems. Powdered coal processes of the fully ~118~iOO
entrained type and of the fluidised bed type now under development can absorb total mine output but at the expense of grinding or pulverising all of the coal, of sacrifices in thermal efficiency in the former case and, in the latter case, of complications in reactor and process engineering, etc.
According to one aspect of the present invention a coal gasification process and apparatus therefor comprises means for supplying fuel to and separately maintaining a fixed bed fuel gasification zone in the upper region of a reactor vessel, supplying additional fuel together with a gasifying agent to initiate and maintain reaction in an entrained fuel gasification zone located in the lower region of the vessel, the gasicication products from the entrained fuel gasification zone passing up through and gasifying fuel in the fixed bed gasification zone, slag from the upper gasification zone passing downwards to mix with slag from the entrained stage and exits via a slag tap outlet to a slag quench system located below the reactor vessel.
~he fixed bed gasification zone may be maintained in the upper region of the vessel by a throat formed with;n the vessel to restrict the downward flow of fuel and support the fuel bed.
Tn an alternative arrangement the fuel bed may be supported on a grate which extends across the vessel. Said grate may be cooled by the circulation of an appropriate coolant through the elements forming the grate.
-~1'18600 In a preferred form of the invention additional gasifying agents are introduced to the fixed bed gasification zone. Said gasifying agents can be introduced above or below the throat or grate.
Methods of carrying out the invention are described in detail below with reference to drawings which illustrate only two specific embodiments, in which Figure 1 is a general cross-sectional view of a coal gasification reactor vessel showing the use of a restricted throat in the vessel, Fi~ure 2 is an enlarged view of part of a similar 10 vessel showing the use of a grate within the vessel, ~i~ure ~ is a b ock flow diagram of a composite gasifier.
me coal gasifier as shown in ~igure 1 comprises a reactor vessel 1 arranged to contain within the upper region of the vessel a fixed bed gasification ~one 2 and within the lower portion of the vessel a fully entrained fuel gasification 70ne 3.
~he gasifier is provided with coal supply chutes 25 which feed lump coal via coal lock hoppers 12 and 13 and coal chutes 14 into the upper region of the reactor vessel. me interior of the vessel 1 is lined with a refractory material 8 and the lower end of the vessel is provided with a slag tap outlet 4, through which liquid slag may ~18600 be discharged into a water filled slag quench chamber 10. After cooling the granular like slag can be removed via a slag lock hopper 11.
A gas burner 5 located below the slag tap 4 provides hot combustisn products which when directed up the slag tap orifice retains the molten iron and slag in the hearth area. One form of slag tap and burner is described more fully in ~ritish Patent Specification No. 1,512,677.
The refractory lining which extends into the hearth zone is provided with cooling coils 9 such that a suitable coolant can be passed through the refractory.
A gas off-take duct 15 is located at the top of the Yessel. The refractory lining of the off-take and of the vessel is provided with cooling coils 16.
A restricted throat 18 may be formed of a cast refractory material and provided with-coolant passageways 17. Other materials may be used. Tuyeres 6 are arranged to inject pulverised fuel and gasifying agents, eg steam, oxygen or oxygen enriched air, into fully entrained gasification zone ~-and tuyeres 7 located above the throat 18 may inject additional gasifying agents into the fixed bed gasification zone 2. Additional tuyeres (not show) or tuyres j may optionally be -( located below the throat 18 to supply the additional gasifying agents.
lhe gasifier when operating comprises a fixed bed gasification zone 3 in the upper regions of the reactor vessel and a fully entrainea gasification zone in the lower portion of the vesael.
~he fixed fuel bed is supported on the restricted throat 18 below-which is the combustion chamber wherein a fully entrained gasification zone is initiated and maintained by the injection of pulverised fuel `
and gasifying agents through the tuyeres 6. ~he products of gasification fxom the entrained zone consisting essentially of steam, c æbon monoxide and hydrogen pass up through t,he throa~ to gasify the fuel in the fixed bed gasification zone above. ~he slag produced in the fixed bea gasification zone runs down through , the throat and the 81a~ produced from the pul~e~ised fuel in the entrained zone below collects together and runs or is drained off through the slag tap into the water quench system. ~he combustion reactions in the fully entrained zone can take place in a vortex, the slag being thrown out on to the combustion chamber walls, or in the turbulence of opposing jets. Since the walls and floor of thi8 chamber are lined with water-cooled coils with the water cooled throat foDming the roof~ all of the wall may be coated in frozen slag to someequilibrium thickness. ~he layer of frozen slag provides protection for the vessel internals and may facilitate the flow dow~
the walls of slag from the upper ~asification zone.
1~18600 Additional steam and oxygen (or oxygen enriched air) can be introduced through tuyeres 7 into the fixed bed gasification zone. Tars and oils can also be introduced through these tuyeres 7 or through tuyeres 6.
It is the ability to distribute the gasifying agent across the full cross-sectional area and to use large coal particularly in the upper bed which enable, with the less strongly caking coals, outputs to be achieved well in excess of the known slagging gasifier.
In the alternative embodiment shown in Figure 2 the fuel bed in the fixed bed gasification zone is supported on a grate 20 which extends across the reactor vessel. The vessel may also be provided with a restricted throat 21 of refractory material and the elements forming the grate and the throat are provided with internal'coolant passageways 22 and 23.
A gasifier, constructed in accordance with the invention, has some of the advantages of both fully entr~;ned and fixed bed gasifiers.
It accommodates the total output of a mine with the minimum of preparation. ~he fixed bed gives the system "carbon capacity", by which we mean a large quantity of carbon present within the reactor which reduces if not eliminates the sensitivity which a fully entrained system has to a loss of fuel feed. It also adds counter-current flow of fuel to product gas and so provides some heat recovery absent in a fully entrained system. It also enhances the production of methane'in passing the product through the bed.
8~;00 _ 8 --A further potential advantage of the composite gasifier iB that it may be arranged for operation on air or oxygen enriched air for the production of low ~tu( 160 Btu/SCF) as a particulate and sulphur-free reducing of synthesis gas, and as a fuel gas for combined cycle power .production or direct boiler firing.
Figure 3 is a block flow'diagram-of the process. Table 1 and ~able
.
Examples of such slagging gasifier plant are those disclosed in 7Jnited Kin.gdom Patent Specification ~o. 977,122 and the Gas Council Research Co~77n;cations ~o's GC 50 and GC 112.
t~
6~0 A slagging gasifier plant of the kind specified represents slagging gasification in its si_plest form and is a form most appropriate to the fixed bed gasification of "lump" coal (nominally 2" - ~") at high pressure in steam and oxygen. It is particularly suited for the production of substitute natural gas (S~G) and synthesis gas.
~he gasifier has an output two or three times greater than the well known c~nd con~entional grate-type gasifier; has a lower steam oonsumption; produces less aqueous liquor; has a greater thermal efficiency and, on the less reactive low fusion point ash coals, has a lower oxygen consumption. ~either the slagging or the grate-type gasifiers can operate with a coal feed which contains a high proportion of coal fines although the slagging gasifier will accommodate the injection of fine coal or char at the tuyeres up to about 10% of the total fuel supply. Future coal supplies may consist of even more fines than those of today and the ability to consume a total mine output will be an important requirement for conservation of resources.
S~G plants in the USA and those that might be built later in Europe are expected to have capacities of 250 MMSCFD and will require about 5~ million tons of coal per year which will come from one or more mines dedicated to the plant. Strip m;n;~g produces a minimum of 2~/o material below ~" in size, mechanised deep coal m;n;ng produces as much as 40~/o while figures as high as 60Yo have been quoted for strip mining of brown coal in Germany. lhe ability to gasify fLne coal therefore could become a major ;f not an essential requirement of future gasification systems. Powdered coal processes of the fully ~118~iOO
entrained type and of the fluidised bed type now under development can absorb total mine output but at the expense of grinding or pulverising all of the coal, of sacrifices in thermal efficiency in the former case and, in the latter case, of complications in reactor and process engineering, etc.
According to one aspect of the present invention a coal gasification process and apparatus therefor comprises means for supplying fuel to and separately maintaining a fixed bed fuel gasification zone in the upper region of a reactor vessel, supplying additional fuel together with a gasifying agent to initiate and maintain reaction in an entrained fuel gasification zone located in the lower region of the vessel, the gasicication products from the entrained fuel gasification zone passing up through and gasifying fuel in the fixed bed gasification zone, slag from the upper gasification zone passing downwards to mix with slag from the entrained stage and exits via a slag tap outlet to a slag quench system located below the reactor vessel.
~he fixed bed gasification zone may be maintained in the upper region of the vessel by a throat formed with;n the vessel to restrict the downward flow of fuel and support the fuel bed.
Tn an alternative arrangement the fuel bed may be supported on a grate which extends across the vessel. Said grate may be cooled by the circulation of an appropriate coolant through the elements forming the grate.
-~1'18600 In a preferred form of the invention additional gasifying agents are introduced to the fixed bed gasification zone. Said gasifying agents can be introduced above or below the throat or grate.
Methods of carrying out the invention are described in detail below with reference to drawings which illustrate only two specific embodiments, in which Figure 1 is a general cross-sectional view of a coal gasification reactor vessel showing the use of a restricted throat in the vessel, Fi~ure 2 is an enlarged view of part of a similar 10 vessel showing the use of a grate within the vessel, ~i~ure ~ is a b ock flow diagram of a composite gasifier.
me coal gasifier as shown in ~igure 1 comprises a reactor vessel 1 arranged to contain within the upper region of the vessel a fixed bed gasification ~one 2 and within the lower portion of the vessel a fully entrained fuel gasification 70ne 3.
~he gasifier is provided with coal supply chutes 25 which feed lump coal via coal lock hoppers 12 and 13 and coal chutes 14 into the upper region of the reactor vessel. me interior of the vessel 1 is lined with a refractory material 8 and the lower end of the vessel is provided with a slag tap outlet 4, through which liquid slag may ~18600 be discharged into a water filled slag quench chamber 10. After cooling the granular like slag can be removed via a slag lock hopper 11.
A gas burner 5 located below the slag tap 4 provides hot combustisn products which when directed up the slag tap orifice retains the molten iron and slag in the hearth area. One form of slag tap and burner is described more fully in ~ritish Patent Specification No. 1,512,677.
The refractory lining which extends into the hearth zone is provided with cooling coils 9 such that a suitable coolant can be passed through the refractory.
A gas off-take duct 15 is located at the top of the Yessel. The refractory lining of the off-take and of the vessel is provided with cooling coils 16.
A restricted throat 18 may be formed of a cast refractory material and provided with-coolant passageways 17. Other materials may be used. Tuyeres 6 are arranged to inject pulverised fuel and gasifying agents, eg steam, oxygen or oxygen enriched air, into fully entrained gasification zone ~-and tuyeres 7 located above the throat 18 may inject additional gasifying agents into the fixed bed gasification zone 2. Additional tuyeres (not show) or tuyres j may optionally be -( located below the throat 18 to supply the additional gasifying agents.
lhe gasifier when operating comprises a fixed bed gasification zone 3 in the upper regions of the reactor vessel and a fully entrainea gasification zone in the lower portion of the vesael.
~he fixed fuel bed is supported on the restricted throat 18 below-which is the combustion chamber wherein a fully entrained gasification zone is initiated and maintained by the injection of pulverised fuel `
and gasifying agents through the tuyeres 6. ~he products of gasification fxom the entrained zone consisting essentially of steam, c æbon monoxide and hydrogen pass up through t,he throa~ to gasify the fuel in the fixed bed gasification zone above. ~he slag produced in the fixed bea gasification zone runs down through , the throat and the 81a~ produced from the pul~e~ised fuel in the entrained zone below collects together and runs or is drained off through the slag tap into the water quench system. ~he combustion reactions in the fully entrained zone can take place in a vortex, the slag being thrown out on to the combustion chamber walls, or in the turbulence of opposing jets. Since the walls and floor of thi8 chamber are lined with water-cooled coils with the water cooled throat foDming the roof~ all of the wall may be coated in frozen slag to someequilibrium thickness. ~he layer of frozen slag provides protection for the vessel internals and may facilitate the flow dow~
the walls of slag from the upper ~asification zone.
1~18600 Additional steam and oxygen (or oxygen enriched air) can be introduced through tuyeres 7 into the fixed bed gasification zone. Tars and oils can also be introduced through these tuyeres 7 or through tuyeres 6.
It is the ability to distribute the gasifying agent across the full cross-sectional area and to use large coal particularly in the upper bed which enable, with the less strongly caking coals, outputs to be achieved well in excess of the known slagging gasifier.
In the alternative embodiment shown in Figure 2 the fuel bed in the fixed bed gasification zone is supported on a grate 20 which extends across the reactor vessel. The vessel may also be provided with a restricted throat 21 of refractory material and the elements forming the grate and the throat are provided with internal'coolant passageways 22 and 23.
A gasifier, constructed in accordance with the invention, has some of the advantages of both fully entr~;ned and fixed bed gasifiers.
It accommodates the total output of a mine with the minimum of preparation. ~he fixed bed gives the system "carbon capacity", by which we mean a large quantity of carbon present within the reactor which reduces if not eliminates the sensitivity which a fully entrained system has to a loss of fuel feed. It also adds counter-current flow of fuel to product gas and so provides some heat recovery absent in a fully entrained system. It also enhances the production of methane'in passing the product through the bed.
8~;00 _ 8 --A further potential advantage of the composite gasifier iB that it may be arranged for operation on air or oxygen enriched air for the production of low ~tu( 160 Btu/SCF) as a particulate and sulphur-free reducing of synthesis gas, and as a fuel gas for combined cycle power .production or direct boiler firing.
Figure 3 is a block flow'diagram-of the process. Table 1 and ~able
2 may be used in conjunction with ~igure 3 to show the material balances est~mPtes for case in.which there is high heat loss from the process and alternati~ely a low heat loss.
. ^ . . .. . . , ~ . . .
' ~ar removal from the product gas may be used to lay dust o,n top of the cbal.bed but used this way the tar will again be recovered in the tar recovery system. ~ar may be gasified by inaecting it preferably through the tuyeres 7 into the fixed bed gasification zone; . , .
Convention~l air-blown fixed bed gasifiers are handicapped by the low temperature or operation imposed by the need to avoid clinker formation a problem which can be eliminated if slaggi~g operation can be employed.
.
me slagging gasifier i8 not particularly suitéd to operation on air, the nitrogen in the air tripling the volume of gases entering the combustion zone and tending to lead to instability and poor ~la~ging conditions. me addition of fines below the fixed bed of fuel in ( 11186{~
-- g the gasifier, constructed in accordance with the invention, will facilitate the use of air or oxygen enriched air for gasification under slagging conditions.
It will be appreciated that the invention, however, does not necessarily depend on the use of a restricted throat or of a water-cooled grate to separate the two gasification æystems, othex means ~ -bf controlling this bounda~y are envisaged and considered within the scope of the invention.
11~8~C~0 TABLE 1: Material Balance Initial Estimates (High Heat Loss Case) -STREAM No 1 2 3 4 TgEAM CONTENT COAL TO F~:~3) TO FIXED FEED TO SLAG TAP TOTAL
FIXED BED BED TUYERES ENT~AINED STAGE BURNER GAS
OMPONENT
COAL (DAF)8045 5363 13408 BURNER GAS
.
. .
STREAM No. 5 6 STREAM CONI'ENT CRUDE GAS WASTE SL~G TOTAL
PRODUCT
OUTLET
COMPONENT
STE~M 2215 2215 TARS* 342 342 _ _ _ . . . .. . .. _ TEMP(C) 736 . _ _ . . _ _ .
PRESSURE = 450 PSIG
* EXCLUDES TAR RECYCLED TO TOP OF FIXED BEDALL FLOWS IN LBS/H
TABLE 2: Mate-rial Balance Initial Estimates .
(Lower Heat Loss Cases) TREAM CONTENT COAL TO F~ TG FIXED FEED TO SLAG TAP TOTAL
FIXED BED BED II~RES ENTRAINED STA OE BURNER GAS
INIET
COMPONENT
CQ~L ~DAF)8281 5521 13802 BURNER GAS
STREAM No. 5 6 gTRE~M CONTENT CRDDE GAS W~STE SLAG TOIAL
PRODUCT
OUTLET
COMPONENT
METHAN.E 931 931 STE~M 2218 2218 TARS* 352 352 OILS ~39 139 SL~G 709 709 TEMP (C~ 730 . ._ . . _ _ _ .
PRESSURE = 450 PSIG
* Excludes tar recycled to top of fixed bed all flows in LBS/H
. ^ . . .. . . , ~ . . .
' ~ar removal from the product gas may be used to lay dust o,n top of the cbal.bed but used this way the tar will again be recovered in the tar recovery system. ~ar may be gasified by inaecting it preferably through the tuyeres 7 into the fixed bed gasification zone; . , .
Convention~l air-blown fixed bed gasifiers are handicapped by the low temperature or operation imposed by the need to avoid clinker formation a problem which can be eliminated if slaggi~g operation can be employed.
.
me slagging gasifier i8 not particularly suitéd to operation on air, the nitrogen in the air tripling the volume of gases entering the combustion zone and tending to lead to instability and poor ~la~ging conditions. me addition of fines below the fixed bed of fuel in ( 11186{~
-- g the gasifier, constructed in accordance with the invention, will facilitate the use of air or oxygen enriched air for gasification under slagging conditions.
It will be appreciated that the invention, however, does not necessarily depend on the use of a restricted throat or of a water-cooled grate to separate the two gasification æystems, othex means ~ -bf controlling this bounda~y are envisaged and considered within the scope of the invention.
11~8~C~0 TABLE 1: Material Balance Initial Estimates (High Heat Loss Case) -STREAM No 1 2 3 4 TgEAM CONTENT COAL TO F~:~3) TO FIXED FEED TO SLAG TAP TOTAL
FIXED BED BED TUYERES ENT~AINED STAGE BURNER GAS
OMPONENT
COAL (DAF)8045 5363 13408 BURNER GAS
.
. .
STREAM No. 5 6 STREAM CONI'ENT CRUDE GAS WASTE SL~G TOTAL
PRODUCT
OUTLET
COMPONENT
STE~M 2215 2215 TARS* 342 342 _ _ _ . . . .. . .. _ TEMP(C) 736 . _ _ . . _ _ .
PRESSURE = 450 PSIG
* EXCLUDES TAR RECYCLED TO TOP OF FIXED BEDALL FLOWS IN LBS/H
TABLE 2: Mate-rial Balance Initial Estimates .
(Lower Heat Loss Cases) TREAM CONTENT COAL TO F~ TG FIXED FEED TO SLAG TAP TOTAL
FIXED BED BED II~RES ENTRAINED STA OE BURNER GAS
INIET
COMPONENT
CQ~L ~DAF)8281 5521 13802 BURNER GAS
STREAM No. 5 6 gTRE~M CONTENT CRDDE GAS W~STE SLAG TOIAL
PRODUCT
OUTLET
COMPONENT
METHAN.E 931 931 STE~M 2218 2218 TARS* 352 352 OILS ~39 139 SL~G 709 709 TEMP (C~ 730 . ._ . . _ _ _ .
PRESSURE = 450 PSIG
* Excludes tar recycled to top of fixed bed all flows in LBS/H
Claims (16)
1. A two-stage coal gasification apparatus comprising means for supplying gasifiable fuel to and separately maintaining a fixed bed fuel gasification zone in the upper region of a reactor vessel, separate means for supplying pulverized gasifiable fuel together with a gasifying agent sufficient to initiate and maintain gasification reaction of the pulverized fuel in an entrained gasification zone located in the lower region of the vessel, means for separately supplying a gasifying agent directly to the fixed bed gasification zone in the upper region of the vessel, and a slag tap outlet from said lower region to a slag quench system located below the reactor vessel, said upper and lower gasification regions being in direct communication with each other such that gasification products from the lower region enter the upper region and, together with said directly supplied gasifying agent, effect gasification of the fuel in the fixed bed gasification zone, slag formed in the upper region being allowed to pass downwardly through said lower region to said slag tap outlet.
2. Apparatus according to claim 1, including a throat formed within the region between said upper and lower regions for maintaining the fixed bed gaification zone in the upper region of the vessel.
3. Apparatus according to claim 1, wherein the fixed bed gasification zone is maintained in the upper region of the vessel by a grate extending across the vessel within the region between said upper and lower regions.
4. Apparatus according to claim 3, wherein means are provided for cooling said grate by the circulation of an appropriate coolant through the elements forming the grate.
5. A two-stage coal gasification process, comprising supplying gasifiable fuel and a gasifying agent directly to and separately maintaining a fixed bed fuel gasification zone in the upper region of a reactor vessel, separately supplying gasifiable pulverized fuel together with a gasifying agent sufficient to initiate and maintain gasification reaction of the pulverized fuel in an entrained gasification zone located in the lower region of the vessel, passing the gasification products from the entrained fuel gasification zone up through the fixed bed gasification zone such that the said gasification products, together with said directly supplied gasifying agent, effect gasification of the fuel in the fixed bed gasification zone, and passing slag from the upper gasification zone downward to mix with slag from the entrained stage and exit via a slag outlet to a slag quench system located below the reactor vessel.
6. Apparatus as claim in claim 1 wherein said directly supplied gasifying agent to said fixed bed fuel gasification zone comprises at least steam.
7. Apparatus as claimed in claim 6 wherein said steam is supplied through tuyeres located in said upper region.
8. A process as claimed in claim 5 wherein said directly supplied gasifying agent to said fixed bed fuel gasification zone comprises at least steam, and is supplied through tuyeres located in said upper region.
9. A two-stage coal gasification process utilizing a reactor vessel having upper and lower regions, a slag tap outlet from the lower region, and means for supporting a fixed fuel bed in the upper region while permitting slag to pass downwardly from the upper region to the slag tap outlet and permitting gases to pass upwardly from the lower region to the upper region, said process comprising supplying to said upper region coal in relatively lump form so as to establish a fixed bed fuel gasification zone, supplying to said lower region relatively fine coal together with a gasifying agent sufficient to initiate and maintain gasification reaction of the fine coal in an entrained mode so as to form an entrained gasification reaction zone in the lower region of the vessel, supplying an additional gasification agent to the fixed bed gasification zone independently of the gasifying agent supplied to said lower region, passing the gasification products from the entrained fuel gasification zone up through the fixed bed gasification zone such that said gasification products and said additional gasifying agent effect gasification of the lump coal in the fixed bed gasification zone, and passing slag from the fixed bed gasification zone downwardly to mix with slag from the entrained gasification zone and exit via said slag tap outlet from the lower region.
10. A process as claimed in claim 9 wherein said additional gasifying agent is supplied directly to said fixed bed gasification zone through tuyeres.
11. A process as claimed in claim 10 wherein said tuyeres open into the upper region of said vessel.
12. A process as claimed in claim 11 wherein said gasifying agent and said additional gasifying agent include steam, and the amount of additional steam gasifying agent supplied directly to said fixed bed gasification zone is greater than the amount of steam gasifying agent supplied to said lower region.
13. A process as claimed in claim 12 wherein said gasifying agent and said additonal gasifying agent both include oxygen, and the amount of additional oxygen gasifying agent supplied directly to said fixed bed gasification zone is less than the amount of oxygen gasifying agent supplied to said lower region.
14. A process as claimed in claim 9 wherein the amount of relatively fine coal supplied to said lower region is at least twenty percent of the amount of relatively lump coal supplied to said upper region such that the gasification products from said relatively fine coal contribute substantially to the total gasification products of the process.
15. A process as claimed in claim 14 wherein the amount of relatively fine coal supplied to said lower region is at least half the amount of relatively lump coal supplied to said upper region such that the gasification products from said relatively fine coal contribute substantially to the total gasification products of the process.
16. A process as claimed in claim 9 wherein the gasification products passed from said entrained fuel gasification zone to said fixed bed gasification zone comprise primarily carbon monoxide, steam and hydrogen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000322023A CA1118600A (en) | 1979-02-21 | 1979-02-21 | Two-stage coal gasification process and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000322023A CA1118600A (en) | 1979-02-21 | 1979-02-21 | Two-stage coal gasification process and apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1118600A true CA1118600A (en) | 1982-02-23 |
Family
ID=4113597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000322023A Expired CA1118600A (en) | 1979-02-21 | 1979-02-21 | Two-stage coal gasification process and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1118600A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2338956A1 (en) * | 2008-10-22 | 2011-06-29 | Mitsubishi Heavy Industries, Ltd. | Coal gasification furnace |
-
1979
- 1979-02-21 CA CA000322023A patent/CA1118600A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2338956A1 (en) * | 2008-10-22 | 2011-06-29 | Mitsubishi Heavy Industries, Ltd. | Coal gasification furnace |
| EP2338956A4 (en) * | 2008-10-22 | 2013-03-13 | Mitsubishi Heavy Ind Ltd | Coal gasification furnace |
| US9487715B2 (en) | 2008-10-22 | 2016-11-08 | Mitsubishi Hitachi Power Systems, Ltd. | Coal gasifier |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4441892A (en) | Process for the gasification of carboniferous material in solid, pulverulent or even lump form | |
| US4153426A (en) | Synthetic gas production | |
| CN101605876B (en) | Method and device for the entrained-flow gasification of solid fuels under pressure | |
| US9175847B2 (en) | Two stage dry feed gasification system | |
| PL190794B1 (en) | Method of and apparatus for obtaining flammable and reducing gas from solid fuels | |
| US3957458A (en) | Gasifying coal or coke and discharging slag frit | |
| US4728360A (en) | Process for the production of molten pig iron and steel pre-products | |
| JPS6027716B2 (en) | Method and apparatus for producing gas from solid fuel | |
| SU1118292A3 (en) | Method of obtaining molten cast iron or steel semiproduct from iron-containing material and device for effecting same | |
| NZ202333A (en) | Gasifying carbonaceous material | |
| Krause et al. | HTW™-gasification of high volatile bituminous coal in a 500 kWth pilot plant | |
| EP0000442A1 (en) | Process and apparatus for the gasification of coal | |
| US4699655A (en) | Process and a plant for the direct reduction of iron oxide particles in a shaft furnace and for smelting the obtained iron sponge particles in a meltdown gasifier | |
| US4298355A (en) | Method for the gasification of coal | |
| US4201571A (en) | Method for the direct reduction of iron and production of fuel gas using gas from coal | |
| CA1274091A (en) | Arrangement for gasifying fuels | |
| GB841569A (en) | Gasification of fuels and decomposition of gases | |
| AU749262B2 (en) | Method for producing liquid pig iron | |
| CA1118600A (en) | Two-stage coal gasification process and apparatus | |
| US4323366A (en) | Apparatus for the gasification of coal | |
| US4865626A (en) | Process for producing gas containing CO and H2 | |
| US3437561A (en) | Agglomerating coal hydrocarbonization process | |
| US2187872A (en) | Gas producer for gasifying granular fuels | |
| CA1194696A (en) | Ash removal and synthesis gas generation from coal | |
| US7883556B1 (en) | Dual fuel slagging gasifier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |