AU2013237711B2

AU2013237711B2 - Gasification system for carbon containing fuel

Info

Publication number: AU2013237711B2
Application number: AU2013237711A
Authority: AU
Inventors: Kenichi Ikeda; Takuya Ishiga; Fumihiko Kiso; Fumihiko Nagaremori; Masanori Santou
Original assignee: Mitsubishi Power Ltd
Current assignee: Electric Power Development Co Ltd; Mitsubishi Power Ltd
Priority date: 2012-10-09
Filing date: 2013-10-04
Publication date: 2016-01-21
Anticipated expiration: 2033-10-04
Also published as: AU2013237711A1; JP2014077031A; CN103710046B; JP6139845B2; CN103710046A

Abstract

{Abstract of the disclosure} A gasification system for carbon-containing fuel comprising: a gasifier for gasifying carbon-containing solid fuel and generating syngas, and a fuel feed 5 system for transferring the carbon-containing solid fuel from a coal hopper into the gasifier by gas, wherein: the gasifier is structured so as to take out the syngas generated by gasifying the carbon-containing fuel from above the gasifier, convert inorganic 10 material included in the carbon-containing fuel to fused slag, and take it out below the gasifier, and the gasification system further comprising: a dust removing part installed on a downstream side of the gasifier for removing dust from the syngas taken out from above the 15 gasifier, a char hopper for collecting char from which dust removed by the dust removing part and is accompanied with the syngas, a char feed system for transferring the char collected by the char hopper from the char hopper to the gasifier by gas, a water washing 20 tower installed on a downstream side of the dust removing part for washing the syngas flowing down through the dust removing part, a slag-cooling water pool installed on a bottom of the gasifier for cooling the fused slag with cooling water fed from outside, and 25 a water feed system for feeding high-temperature water raised in temperature by the fused slag in the slag cooling water pool from the slag-cooling water pool to the downstream side of the gasifier or an upstream side of the dust removing part and cooling the syngas taken 5 out from the gasifier. -- - -- ---- -- - 39 c ~ ~271 11 N2 23 Ai 8 30---- b4 9 N O0 Air 18

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title Gasification system for carbon containing fuel The following statement is a full description of this invention, including the best method of performing it known to me/us: 5102 - la The present invention relates to a gasification system for carbon-containing fuel such as coal and more particularly to a gasification system for carbon 5 containing fuel that achieves both discharged water and exhaust heat utilization and waste matter reduction. Syngas generated by gasifying carbon-containing fuel such as coal reaches 1000'C or higher at the gasifier exit. To remove dust from the syngas and 10 remove impurities such as chlorine contents and sulfur contents so as to purify it, the syngas must be cooled to less than 400'C. A gasification system for power generation recovers heat when cooling the syngas so as to increase the energy efficiency. 15 The syngas that left the gasifier is accompanied with many solids composed of unburned carbon and ash contents. Therefore, in the process of cooling the syngas by recovering heat, the two troubles described below must be prevented. 20 One of them is that in a high-temperature environment of 1000'C or higher, it is necessary to prevent adhesion (slagging) of fused ash contents to -2 the heat exchanger tube. The other one is that in the process of cooling the syngas to 800*C to 900'C or so, it is necessary to prevent adhesion (fouling) of precipitated alkali metal 5 salt (such as Na 2

SO

4 ) to the heat exchanger tube. As a trouble prevention measure aforementioned, the syngas that left the gasifier is cooled in two stages. Here, from the upstream (the gasifier) side, the two stages are called a first heat recovery unit and a 10 second heat recovery unit. In the first heat recovery unit, the syngas is cooled to 800'C to 900 0 C and heat is recovered by the water cooling wall. In the second heat recovery unit, the syngas is cooled to less than 400 0 C and heat is recovered by the heat exchanger tubes 15 installed in the heat recovery unit and on the wall surface. However, the heights of the first heat recovery unit and second heat recovery unit reach several times that of the gasifier and therefore cause rise factors 20 to the equipment and construction costs of the gasification system. To reduce such equipment and construction costs, for example, in Japanese Patent Laid-Open No. Hei 9(1997)-194855, a technology relating to the cooling system of the syngas for spraying a part 25 of washing water for washing the syngas in the - 3 purification process into the heat recovery unit and miniaturizing the heat recovery unit is disclosed. Further, in Japanese Patent Laid-Open No. Sho 5 59(1984)-136389, a technology relating to the cooling system that a part of washing water for washing the syngas in the purification process is sprayed to the syngas and furthermore, the washing water sprayed to the syngas passes through the water of the slag-cooling 10 water pool is disclosed. In this cooling system, fused slag accompanied with the syngas in the slag-cooling water pool can be removed and the heat recovery unit for cooling the syngas can be made unnecessary. {Citation List} 15 {Patent Literature} {Patent Literature 11 Japanese Patent Laid-Open No. Hei 9(1997)-194855 {Patent Literature 2 Japanese Patent Laid-Open No. Sho 59(1984)-136389 20 In the slag-cooling water pool, fused slag heated at the melting point (1200'C to 1500'C or so, depending on the coal properties or higher of coal ash flows down in large quantities. The fused slag is suddenly cooled in the slag-cooling water pool to granulated slag which is amorphous (grassy) and granular. For this reason, the slag-cooling water in the slag-cooling water pool is raised in temperature by the heat from the fused slag. 5 To prevent the slag-cooling water in the slag cooling water pool from evaporation, the slag-cooling water is subjected to circulation cooling. The reason is to prevent a reduction in the slag-cooling water quantity and a reduction in the temperature of the 10 gasifier due to evaporation of the slag-cooling water. The temperature of the slag-cooling water raised in temperature in the slag-cooling water pool, even if it is set to less than 100 0 C, at which the cooling water does not boil even at the normal pressure, is higher 15 than the normal temperature by several tens of degrees Celsius. Further, the mass flow rate of the slag-cooling water for performing circulation cooling, if the case of a coal gasifier is used as an example, reaches about 20 0.5 to 2 times (depending on the ash content and melting point) that of coal. Therefore, the sensible heat of the slag-cooling water raised in temperature in the slag-cooling water pool, in certain circumstances, reaches about 1% of the amount of heat of coal inputted 25 into the gasifier.

- 5 However, in the technology disclosed in Japanese Patent Laid-Open No. Hei 9(1997)-194855, there is no mentioning of the utilization of exhaust heat of high temperature water pulled out from the slag-cooling 5 water pool. Further, in the technology disclosed in Japanese Patent Laid-Open No. Sho 59(1984)-136389, for high temperature water pulled out from the slag-cooling water pool, the heat exchanger is installed and the 10 exhaust heat of the high-temperature water is used as a heat source for feed water heating at the normal temperature. In this case, at the exit of the heat exchanger, the high-temperature water pulled out from the slag-cooling water pool is higher than the normal 15 temperature, so that the exhaust heat of the high temperature water is not used efficiently. It is desirable that embodiments of the present invention provide a gasification system for carbon containing fuel for cooling syngas taken out from the 20 gasifier by efficiently using the exhaust heat of the high-temperature water generated in the gasification system and for reducing the carbon loss and waste matter generated from the carbon-containing fuel. According to the present invention, there is 25 provided, a gasification system for carbon-containing fuel - 6 comprising: a gasifier for gasifying carbon-containing solid fuel and generating syngas, and a fuel feed system for transferring the carbon-containing solid fuel from a coal hopper into the gasifier by gas, 5 wherein: the gasifier is structured so as to take out the syngas generated by gasifying the carbon-containing fuel from above the gasifier, convert inorganic material included in the carbon-containing fuel to fused slag, and take it out below the gasifier, and the 10 gasification system further comprising: a dust removing part installed on a downstream side of the gasifier for removing dust from the syngas taken out from above the gasifier, a char hopper for collecting char from which dust removed by the dust removing part and is 15 accompanied with the syngas, a char feed system for transferring the char collected by the char hopper from the char hopper to the gasifier by gas, a water washing tower installed on a downstream side of the dust removing part for washing the syngas flowing down 20 through the dust removing part, a slag-cooling water pool installed on a bottom of the gasifier for cooling the fused slag with cooling water fed from outside, and a water feed system for feeding high-temperature water raised in temperature by the fused slag in the slag 25 cooling water pool from the slag-cooling water pool to the downstream side of the gasifier and to an upstream side of the dust removing part to cool the syngas taken out from the gasifier. According to an embodiment of the present invention, 5 a gasification system for carbon-containing fuel for cooling the syngas that left a gasifier by efficiently using the exhaust heat of high-temperature water generated in the gasification system and for reducing the carbon loss and waste matter generated from the 10 carbon-containing fuel can be achieved. The present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, briefly described as follows. {Fig. 11 Fig. 1 is a system diagram showing the 15 constitution of the coal gasification composite power generation plant including the gasification system for carbon-containing fuel which is the first embodiment of the present invention. {Fig. 2} Fig. 2 is a system diagram showing the 20 constitution of the coal gasification composite power generation plant including the gasification system for carbon-containing fuel which is the second embodiment of the present invention. {Fig. 31 Fig. 3 is a system diagram showing the 25 constitution of the coal gasification composite power - 8 generation plant including the gasification system for carbon-containing fuel which is the third embodiment of the present invention. {Fig. 4} Fig. 4 is a system diagram showing the 5 constitution of the coal gasification composite power generation plant including the gasification system for carbon-containing fuel which is the fourth embodiment of the present invention. {Fig. 51 Fig. 5 is a system diagram showing the 10 constitution of the coal gasification composite power generation plant including the gasification system for carbon-containing fuel which is the fifth embodiment of the present invention. The gasification systems for carbon-containing fuel 15 which are the embodiments of the present invention will be explained below by referring to the drawings. {Embodiment 11 The coal gasification composite power generation plant including the gasification system for carbon 20 containing fuel which is the first embodiment of the present invention will be explained by referring to Fig. 1. The gasification system for carbon-containing fuel of this embodiment shown in Fig. 1 is a gasification 25 system for carbon-containing fuel that the heat -9 recovery unit for efficiently using the sensible heat of high-temperature water generated in the cooling water pool of fused slag and for cooling the syngas generated by gasifying carbon-containing fuel is 5 miniaturized. Using the case in which coal is used as fuel and a gas turbine and a steam turbine are driven by the syngas as an example, the gasification system for carbon-containing fuel which is the first embodiment of 10 the present invention will be explained by referring to Fig. 1. Fig. 1 is a system diagram showing the constitution of the coal gasification composite power generation plant including the gasification system for carbon 15 containing fuel which is the first embodiment of the present invention, comprising a coal hopper 2 for storing coal of carbon-containing fuel, an air separation unit 4 for manufacturing oxygen and nitrogen from air, a fuel feed system a for transferring coal 20 from the coal hopper 2 to a gasifier 3 by gas, the gasifier 3 for burning both of the coal fed via the fuel feed system a and the oxygen of a gasifying agent fed from the air separation unit 4 to generate syngas 5, a dust removing unit 8 installed on the downstream side 25 of the gasifier 3 for removing dust from the syngas 5 - 10 that left the gasifier 3 and collecting char 9 included in the syngas 5, a heat exchanger 10 and a venturi 11 for cooling the syngas 5 after dust removal, a water washing tower 13 for removing halogen substances 5 included in the syngas 5 and fine dust not collected by the dust removing unit 8, and a desulfurizer 17 for removing sulfur in the syngas 5. Further, the char 9 collected by the dust removing unit 8 is stored in a char hopper 25, is transferred by 10 nitrogen separated from air by the air separation unit 4 via a char feed system b, and is reinputted into the gasifier 3. Furthermore, syngas 39 after desulfurization by the desulfurizer 17 is fed to the heat exchanger 10 of the 15 syngas from the desulfurizer 17 and is reheated, and then is fed to the gas turbine device as fuel. The gas turbine device is composed of a compressor 24 for compressing air, a gas turbine combustor 18 for mixing and burning the syngas 39 fed as fuel with air 20 compressed by the compressor 24, thereby generating high-temperature combustion gas, and a turbine 19 driven by the combustion gas generated by the gas turbine combustor 18. Further, the exhaust gas that left the turbine 19 25 is fed to an exhaust gas boiler 20 for recovering - 11 exhaust heat of the exhaust gas to generate steam and then is discharged into the atmosphere from a chimney 22. The steam generated by the exhaust gas boiler 20 is 5 fed to a steam turbine 21 composing the steam turbine device to drive the steam turbine 21. The steam turbine device is structured so that the steam flowing down through the steam turbine 21 is cooled by a steam condenser 26 to condensed water and the condensed water 10 is fed to the exhaust gas boiler 20. The coal gasification composite power generation plant including the gasification system for carbon containing fuel which is the present embodiment having the aforementioned constitution will be explained below 15 more in detail. Coal 1 is transferred from the coal hopper 2 to the gasifier 3 by nitrogen manufactured by the air separation unit 4. The oxygen manufactured by the air separation unit 4 is fed to the gasifier 3 as a gasifying agent for the coal 1. 20 The gasifier 3 gasifies (partial combustion) the coal 1 by the oxygen manufactured by the air separation unit 4 and generates syngas 5 containing CO and H 2 as main components. The coal 1 contains about 10 wt% of ash (inorganic material). 25 The syngas 5 generated by the gasifier 3 is used - 12 for gas fuel for power generation, so that it must be separated from ash. Therefore, the combustion temperature in the gasifier 3 is raised to the melting point of ash or higher, thus ash is converted to fused 5 slag. The gasifier 3 pulls out the gaseous syngas 5 upward from the gasifier 3 and pulls out the liquid fused slag downward from the gasifier 3, thereby takes out the syngas 5 from the coal 1. Therefore, the 10 temperature of the syngas 5 at the exit of the gasifier 3 reaches 1000'C or higher. To use the syngas 5 as gas fuel, a purification process of removing impurities such as dust removal, demineralization, and desulfurization is necessary. 15 Therefore, the syngas 5 must be cooled to less than 4000C. With the syngas 5 that left the gasifier 3, granular char composed of unburned carbon and ash are accompanied. Further, in the process of cooling the syngas 5 at 20 10000C or higher, troubles such as adhesion (slagging) of fused ash to the heat exchanger tube and adhesion (fouling) of precipitated alkali metal salt (such as Na 2

SO

4 ) to the heat exchanger tube must be prevented. Therefore, the heat recovery unit 7 for cooling the 25 syngas 5 is installed on the upper portion of the - 13 gasifier 3. Inside the heat recovery unit 7, no heat exchanger tube is installed and the syngas 5 is cooled to 800'C to 9004C by the water cooling wall. This is to prevent slagging and fouling. 5 The syngas 5 that left the heat recovery unit 7 is fed to the dust removing unit 8 installed on the downstream side of the gasifier 3 and is removed dust, and the char 9 is collected. The char 9 collected from the syngas 5 by the dust removing unit 8 is fed to the 10 char hopper 25, is stored in the char hopper 25, and similarly to the coal 1, is transferred by the nitrogen fed from the air separation unit 4, and is reinputted from the char hopper 25 into the gasifier 3 via a char feed system d. 15 The syngas 5 after dust is removed by the dust removing unit 8 is cooled to 300'C or lower by the heat exchanger 10 for the syngas which is installed on the downstream side of the dust removing unit 8 and furthermore, is fed to the venturi 11 and the water 20 washing tower 13 which are installed respectively on the downstream side of the heat exchanger 10 for the syngas, and is cooled to about 100 0 C. In the water washing tower 13, the halogen substances included in the syngas 5 and fine dust not 25 collected by the dust removing unit 8 are removed.

- 14 Furthermore, by the desulfurizer 17 installed on the downstream side of the water washing tower 13, sulfur in the syngas 5 is removed. The sulfur collected from the syngas 5 by the desulfurizer 17 is burned in a 5 sulfur combustion furnace 23. The syngas 39 desulfurized by the desulfurizer 17 is cooled at about 400C, is fed to the heat exchanger 10 for the syngas from the desulfurizer 17 to be reheated, and is fed to the gas turbine combustor 18 composing 10 the gas turbine device as fuel. Here, the syngas 39 desulfurized by the desulfurizer 17 is mixed with air fed from the compressor 24 in the gas turbine combustor 18, is burned, and generates high-temperature combustion gas, 15 The combustion gas generated in the gas turbine combustor 18 drives the turbine 19, and the combustion exhaust gas that left the turbine 19 is fed to the exhaust gas boiler 20, and the exhaust heat of the combustion exhaust gas is recovered by the exhaust gas 20 boiler 20, and the steam generated by the exhaust gas boiler 20 drives the steam turbine 21. On the other hand, the fused slag generated in the gasifier 3 increases to 12000C or higher, so that it is cooled to solid slag 6 and is collected from the 25 gasifier 3. In the coal gasification composite power - 15 generation plant including the gasification system for carbon-containing fuel of the present embodiment, the case in which the fused slag is suddenly cooled by slag-cooling water 14 and is collected as amorphous 5 (glassy) granulated slag is shown. Right under the gasifier 3, a slag-cooling water pool 12 for storing the slag-cooling water 14 is installed. The slag-cooling water 14 stored in the slag-cooling water pool 12 is heated by the fused slag 10 flowing down at high temperature to high-temperature water 15, though in the high-temperature water 15, solids such as slag and char floating in the water are included. Therefore, the high-temperature water 15 heated by 15 the slag-cooling water pool 12 is pulled out and solids 30 such as the aforementioned slag and char must be treated. The high-temperature water 15 heated by the slag cooling water pool 12 can be operated conveniently at 20 less than 100 0 C (for example, 80*C) at which it does not boil even at the normal pressure. In this case, the mass flow rate of the high-temperature water 15 reaches about 0.5 to 2 times (depending on the ash content or melting point) that of coal. 25 Therefore, in the coal gasification composite power - 16 generation plant including the gasification system for carbon-containing fuel which is the first embodiment of the present invention shown in Fig. 1, a water treatment system c for treating the high-temperature 5 water 15 heated by the slag-cooling water pool 12 for cooling the syngas 5 generated by the gasifier 3 is arranged. The water treatment system c for treating the high temperature water 15 includes a slurry pump 58 for 10 pumping the high-temperature water 15 heated the slag cooling water pool 12 and the high-temperature water 15 obtained by heating the slag-cooling water 14 fed to the slag-cooling water pool 12 in the slag-cooling water pool 12, as aforementioned, becomes high 15 temperature water 27 including solids such as slag and char floating in the water by the fused slag flowing down at a high temperature, so that the gasification system is structured so as to pressurize it by the slurry pump 58 and feed the high-temperature water 27 20 including the solids into the syngas 5 on the downstream side of the gasifier 3 via the water treatment system c. The water treatment system c is connected on the downstream side of the heat recovery unit 7 installed 25 on the upper portion of the gasifier 3 and the - 17 gasification system is structured so as to feed the high-temperature water 27 including the solids led via the water treatment system c into the gasifier 3 or into the syngas 5 that left the gasifier 3 and permit 5 the high-temperature water 27 to flow into the dust removing unit 8. The water treatment system c for treating the aforementioned high-temperature water 15 is installed, thus the high-temperature water 15 obtained by heating 10 the slag-cooling water 14 in the slag-cooling water pool 12 is pumped by the slurry pump 58 via the water treatment system c, and is fed to the gasifier 3 or the dust removing unit 8 on the downstream side of the gasifier 3 as the high-temperature water 27 including 15 the solids and is used to cool the syngas 5. In the coal gasification composite power generation plant including the gasification system for carbon containing fuel of the present embodiment, the constitution that on the downstream side of the heat 20 recovery unit 7 installed on the upper portion of the gasifier 3, the high-temperature water 27 including the solids is fed from the slag-cooling water pool 12 via the water treatment system c is described, though the water treatment system c may be arranged so as to feed 25 the high-temperature water 27 including the solids into - 18 the heat recovery unit 7 of the gasifier 3. As shown in the coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the present embodiment, when 5 the high-temperature water 15 (the high-temperature water 27 including the solids) is pumped by the slurry pump 58 from the slag-cooling water pool 12 via the water treatment system c and is mixed with the syngas 5 generated by the gasifier 3, the following four effects 10 are obtained. The first effect is reductions in the equipment cost and construction cost. Using the evaporative latent heat and sensible heat of the high-temperature water 15 fed from the slag-cooling water pool 12 via 15 the water treatment system c, the syngas 5 that left the gasifier 3 is cooled, thus the heat recovery unit 7 of the gasifier 3 can be miniaturized. The second effect is improvement of the energy efficiency by use of the exhaust heat of the high 20 temperature water 15 (the high-temperature water 27 including the solids) fed from the slag-cooling water pool 12 via the water treatment system c. Furthermore, the temperature of the high-temperature water 15 fed from the slag-cooling water pool 12 via the water 25 treatment system c is higher than the normal - 19 temperature, thus the high-temperature water 15 is apt to evaporate when it is mixed with the syngas 5 generated by the gasifier 3 and the syngas 5 can be cooled advantageously. 5 The third effect is a reduction in waste matter and carbon loss. The solids 30 such as slag and char becoming waste matter which are included in the high temperature water 15 (the high-temperature water 27 including the solids) fed from the slag-cooling water 10 pool 12 via the water treatment system c are mixed with the syngas 5 that left the gasifier 3. And, the solids 30 included in the high-temperature water 15 are collected by the dust removing unit 8 and is reinputted from the char hopper 25 into the gasifier 3 together 15 with the char 9, thus the weight of the solids 30 becoming waste matter can be reduced. Furthermore, the carbon loss included in the solids 30 can be reduced. The fourth effect is an increase in the H 2 concentration in the syngas 5 generated in the gasifier 20 3 due to shift reaction promotion. A shift reaction formula is expressed by Formula (1). CO + H20 -> CO 2 + H2 .... (1) The shift reaction is known to progress in an environment exceeding 1000 0 C. Therefore, when the 25 syngas 5 immediately after leaving the gasifier 3 is - 20 water-sprayed, for example, in the syngas cooling portion 7, the H2 concentration in the syngas 5 is expected to increase due to the shift reaction. As described in the fifth embodiment which will be 5 described later, if a CO 2 collection means from the syngas 5 generated in the gasifier 3 is installed, the main component of the syngas 5 becomes H2. The syngas 5 with the main component changed to H 2 can be used not only for gas fuel for power generation but also for 10 chemical raw materials such as methanol and ammonia. In the gasification system for carbon-containing fuel having the aforementioned constitution of the present embodiment, the high-temperature water 15 fed from the slag-cooling water pool 12 via the water 15 treatment system c and the syngas 5 generated in the gasifier 3 are mixed and the syngas 5 is cooled effectively, thus the effects such as simplification of the system constitution, improvement of the energy efficiency by use of the exhaust heat, waste matter 20 reduction, and realization of high value added of the syngas 5 can be expected. According to the present embodiment, a gasification system for carbon-containing fuel for cooling the syngas that left the gasifier by efficiently using the 25 exhaust heat of high-temperature water generated in the - 21 gasification system and for reducing the carbon loss and waste matter generated from the carbon-containing fuel can be achieved. {Embodiment 2} 5 Next, the coal gasification composite power generation plant including the gasification system for carbon-containing fuel which is the second embodiment of the present invention will be explained by referring to Fig. 2. The coal gasification composite power 10 generation plant including the gasification system for carbon-containing fuel of the present embodiment shown in Fig. 2 is the same as the coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the 15 first embodiment shown in Fig. 1 in the basic constitution, so that the explanation of the constitutions common to the two is omitted and the different constitutions will be explained below. In the gasification system for carbon-containing 20 fuel of the present embodiment shown in Fig. 2, the high-temperature water 15 heated by the fused slag in the slag-cooling water pool 12 right under the gasifier 3 is pulled out from the slag-cooling water pool 12 via the water feed system c and is fed to a solid 25 separation portion 29 installed in the water feed - 22 system c, and the solids 30 included in the high temperature water 15 are separated by the solid separation portion 29. High-temperature water 31 from which the solids 5 have been separated by the solid separation portion 29 is pumped by a pump 16 installed in the water feed system c, is fed to the syngas flow path, which is the zone from the downstream side of the gasifier 3 to the dust removing unit 8 via the water feed system c, 10 through which the syngas taken out from the gasifier flows down, is mixed with the syngas 5, and cools the syngas 5. The drawing shows the case in which the gasification system for carbon-containing fuel of the 15 present embodiment feeds the high-temperature water 31 from which the solids have been separated by the solid separation portion 29 installed in the water feed system c used to pull out the heated high-temperature water 31 from the slag-cooling water pool 12 to the 20 downstream side of the heat recovery unit 7 installed in the gasifier 3 via the water feed system c. On the other hand, the solids 30 separated from the high-temperature water 31 by the solid separation portion 29 installed in the water feed system c are 25 reinputted into the gasifier 3 from the solid - 23 separation portion 29 via the solid feed system d. Here, the solids 30 are fine slag and char 9, The combustible articles (mostly carbon) in the char 9 reinputted into the gasifier 3 are gasified in the 5 gasifier 3 to the syngas 5. The ash and slag in the char 9 are converted to fused slag, flow down into the slag-cooling water pool 12 installed in the lower portion of the gasifier 3, and are collected as the slag 6. 10 The gasification system for carbon-containing fuel of the present embodiment is valid when the solids 30 are included in a large quantity in the high temperature water 15 pulled out from the slag-cooling water pool 12 and it is difficult to directly feed the 15 high-temperature water 15 including a large quantity of the solids 30 to the downstream side of the gasifier 3 or to the upstream side of the dust removing part 8. Namely, the above applies to the following case: the solids 30 included in the high-temperature water 15 20 pulled out from the slag-cooling water pool 12 are in large quantities and therefore the slurry pump 58 for raising the pressure of the high-temperature water 15 which is installed in the water feed system c may not be used, the nozzle for spraying the high-temperature 25 water 15 fed to the syngas 5 via the water feed system - 24 c may be blocked, or the heat recovery unit 7 for feeding the high-temperature water 15 via the water feed system c or the pipe through which the syngas 5 flows down may be damaged. 5 According to the present embodiment, a gasification system for carbon-containing fuel for cooling the syngas that left the gasifier by efficiently using the exhaust heat of high-temperature water generated in the gasification system and for reducing the carbon loss 10 and waste matter generated from the carbon-containing fuel can be achieved. {Embodiment 3) Next, the coal gasification composite power generation plant including the gasification system for 15 carbon-containing fuel which is the third embodiment of the present invention will be explained by referring to Fig. 3. The coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the present embodiment shown 20 in Fig. 3 is the same as the coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the first embodiment shown in Fig. 1 in the basic constitution, so that the explanation of the 25 constitutions common to the two is omitted and the - 25 different constitutions will be explained below. In the gasification system for carbon-containing fuel of the present embodiment shown in Fig. 3, the high-temperature water 15 heated by the fused slag in 5 the slag-cooling water pool 12 right under the gasifier 3 is pulled out from the slag-cooling water pool 12 via the water feed system c and is fed to the solid separation portion 29 installed in the water feed system c, and the solids 30 included in the high 10 temperature water 15 are separated by the solid separation portion 29. The solids 30 separated from the high-temperature water 31 by the solid separation portion 29 are fed to the char hopper 25 from the solid separation portion 29 15 via a solid feed system e and are mixed with the char 9 collected from the dust removing unit 8 for removing dust from the syngas 5 taken out from the gasifier 3 in the char hopper 25. The solids 30, together with the char 9, are 20 transferred by nitrogen fed from the air separation unit 4 and are reinputted into the gasifier 3 from the char hopper 25 via the char feed system b. An advantage of the gasification system for carbon containing fuel of the present embodiment is that the 25 solids 30 are fed to the gasifier 3 via the existing - 26 char feed system b, so that the conventional operation method can be applied to the gasifier 3. However, a process of heating the solids 30 is necessary. The char 9 collected by the dust removing 5 unit 8 thermally insulates the char hopper 25 and the char feed system b to the gasifier 3, so that moisture is prevented from condensation. Therefore, the solids 30 must be heated to the similar temperature (about 200 0 C) to the char 9. 10 According to the present embodiment, a gasification system for carbon-containing fuel for cooling the syngas that left the gasifier by efficiently using the exhaust heat of high-temperature water generated in the gasification system and for reducing the carbon loss 15 and waste matter generated from the carbon-containing fuel can be achieved. (Embodiment 4) Next, the coal gasification composite power generation plant including the gasification system for 20 carbon-containing fuel which is the fourth embodiment of the present invention will be explained by referring to Fig. 4. The coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the present embodiment shown 25 in Fig. 4 is the same as the coal gasification - 27 composite power generation plant including the gasification system for carbon-containing fuel of the first embodiment shown in Fig. 1 in the basic constitution, so that the explanation of the 5 constitutions common to the two is omitted and the different constitutions will be explained below. In the gasification system for carbon-containing fuel of the present embodiment shown in Fig. 4, the syngas 5 with dust removed by the dust removing unit 8 10 is cooled to 300 0 C or lower by the syngas 5 via the desulfurizer 17 in the heat exchanger 10 installed on the downstream side of the dust removing unit 8, and furthermore, is fed always to the venturi 11 and the water washing tower 13 which are installed on the 15 downstream side of the heat exchanger 10, and is cooled to about 100 0 C. In the venturi 11 and the water washing tower 13, the syngas 5 is cooled by gas-liquid contact with liquid cooling water which is makeup water 36 supplied 20 to the venturi 11 and the water washing tower 13 from the outside. The cooling water of the venturi 11 and the water washing tower 13, in the process of cooling the syngas 5, is heated to 100*C or higher by the syngas 5. The total flow rate of this cooling water reaches 25 about 1 to 2 times the feed rate of the coal 1 to the - 28 gasifier 3. When temporarily setting the cooling water temperature to 100'C and making the flow rate similar to the feed rate of the coal 1, the sensible heat of the 5 cooling water heated due to the gas-liquid contact with the syngas 5 in the venturi 11 and the water washing tower 13 becomes about 1% of the total amount of heat of coal. Therefore, in the gasification system for carbon 10 containing fuel of the present embodiment, heated water feed systems fl and f2 for pulling out a part of the cooling water heated due to the gas-liquid contact with the syngas 5 in the venturi 11 and the water washing tower 13 respectively from the venturi 11 and the water 15 washing tower 13, spraying a part of the cooling water heated from the venturi 11 and the water washing tower 13 into the zone between the exit of the gasifier 3 and the dust removing unit 8, thereby cooling the syngas 5 taken out from the gasifier 3 are arranged respectively. 20 The cooling water sprayed into the zone between the exit of the gasifier 3 and the dust removing unit 8 from the venturi 11 and the water washing tower 13 via the heated water feed systems f1 and f2 for cooling the syngas 5, when mixed with the syngas 5, is apt to 25 evaporate in addition to the own sensible heat and can - 29 cool efficiently the syngas 5. Further, including the water feed system c for feeding the high-temperature water 31 heated by the above-mentioned slag-cooling water pool 12 and from 5 which the solids 30 have been separated in the gasification system for carbon-containing fuel of the first embodiment, the heated cooling water fed by the heated water feed systems fl and f2 may be integrated into one system or the cooling water may be sprayed to 10 the syngas 5 in the current multiple systems. From the viewpoint of the easiness of evaporation of cooling water, a method of spraying cooling water to the syngas 5 to cool it using a plurality of systems of the water feed system c and the heated water feed 15 systems fl and f2 is acceptable and for the order, a gasification system for carbon-containing fuel for feeding the high-temperature water 31 (lower than 100 0 C in the first embodiment aforementioned) with the solids 30 separated to the upstream side where the temperature 20 of the syngas 5 is high via the water feed system c and feeding the cooling water (1000C or higher) heated in the venturi 11 and the water washing tower 13 to the downstream side via the heated water feed systems fl and f2 is recommended. 25 For this, it may be considered that the high- - 30 temperature water 31 with the solids 30 separated via the water feed system c is sprayed to the syngas 5 on the upstream side in the zone between the exit of the gasifier 3 and the dust removing unit 8, thus the 5 temperature of the syngas 5 may be lowered to 4000C to 700 0 C or so (depending on the property of the coal 1, the flow rate and temperature of the high-temperature water 31 with the solids 30 separated, and the evaporation rate). 10 To cool the syngas 5 by further water spray, it is desirable to use cooling water 33 and 35 heated in the venturi 11 and the water washing tower 13 in which the temperature is high and water is easily evaporated to cool the syngas 5. 15 Therefore, so as to keep the syngas 5 at a predetermined temperature of lower than 400 0 C, the cooling water 33 and 35 heated in the venturi 11 and the water washing tower 13 are pulled out and the flow rates of the cooling water 33 and 35 sprayed to the 20 syngas 5 on the downstream side in the zone between the exit of the gasifier 3 and the dust removing unit 8 via the heated water feed systems f1 and f2 are adjusted, thus a gasification system for carbon-containing fuel for suppressing generation of condensed water in the 25 dust removing unit 8 can be constructed.

- 31 Hereinafter, the system of the cooling water in the venturi 11 and the water washing tower 13 in the gasification system for carbon-containing fuel of the present embodiment will be explained. 5 The cooling water 33 of the venturi 11 is heated due to the gas-liquid contact with the syngas 5 reaching close to 300 0 C, so that it is cooled to the normal temperature by a high-temperature heat exchanger 32 and is reinputted into the venturi 11. 10 The temperature of the cooling water 33 in the venturi 11 which is heated in the venturi 11 reaches about 150 0 C. A part of the heated cooling water 33 in the venturi 11 is pulled out from the venturi 11, and the cooling water 33 is sprayed to and mixed with the 15 syngas 5 on the downstream side of the gasifier 3 from the venturi 11 via the heated water feed system fl, thus using the evaporative latent heat and sensible heat of the cooling water 33, the syngas 5 can be cooled effectively. 20 Particularly, the temperature of a part of the cooling water 33 of the venturi 11 is about 150 0 C, and it is more easily evaporated and is more easily handled than water at the normal temperature. Further, to ensure the flow rate of the cooling water 33 of the 25 venturi 11, the system is structured so as to feed the - 32 makeup water 36 from the outside on the downstream side of the high-temperature heat exchanger 32 and feed it to the venturi 11. As for the cooling water 35 of the water washing 5 tower 13, similarly to the above-mentioned cooling water 33 of the venturi 11, it is desirable to use a part of the cooling water 35 to cool the syngas 5. Namely, a part of the heated cooling water 35 of the water washing tower 13 is pulled out from the water 10 washing tower 13, and the cooling water 35 is sprayed to and mixed with the syngas 5 on the downstream side of the gasifier 3 from the water washing tower 13 via the heated water feed system f2, thus using the evaporative latent heat and sensible heat of the 15 cooling water 35, the syngas 5 can be cooled effectively. The temperature of the cooling water 35 of the water washing tower 13 that left the water washing tower 13 is about 100'C, which is lower than the 20 temperature of the above-mentioned cooling water 33 of the venturi 11, though the characteristics that it is more easily evaporated and is more easily handled than water at the normal temperature are the same. Further, to ensure the flow rate of the cooling water 35 of the 25 water washing tower 13, the system is structured so as - 33 to feed the makeup water 36 from the outside on the downstream side of a low-temperature heat exchanger 34 and feed it to the water washing tower 13. From the above-mentioned, the gasification system 5 for carbon-containing fuel of the present embodiment is structured so that the water feed system c for feeding the high-temperature water 31 generated in the slag cooling water pool 12 of the gasifier 3 and the heated water feed systems fl and f2 for feeding the high 10 temperature water 33 and 35 generated in the venturi 11 and the water washing tower 13 are arranged, and the high-temperature water is fed to the downstream side of the gasifier 3 or the upstream side of the dust removing unit 8 and is used to cool the syngas 5 15 generated in the gasifier 3, thus it is possible to achieve both improvement of the energy efficiency due to use of the exhaust heat of the plant and cost down due to miniaturization of the heat recovery unit for cooling the syngas 5. 20 According to the present embodiment, a gasification system for carbon-containing fuel for cooling the syngas that left the gasifier by efficiently using the exhaust heat of high-temperature water generated in the gasification system and for reducing the carbon loss 25 and waste matter generated from the carbon-containing - 34 fuel can be achieved. {Embodiment 5} Next, the coal gasification composite power generation plant including the gasification system for 5 carbon-containing fuel which is the fifth embodiment of the present invention will be explained by referring to Fig. 5. The coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the present embodiment shown 10 in Fig. 5 is the same as the coal gasification composite power generation plant including the gasification system for carbon-containing fuel of the first embodiment shown in Fig. 1 in the basic constitution, so that the explanation of the 15 constitutions common to the two is omitted and the different constitutions will be explained below. For the transfer medium of the coal 1 and the char 9 to the gasifier 3, a part of CO 2 52 collected by CO 2 collection means which will be described later is used. 20 This CO 2 is defined as CO 2 53 for reinput into the gasifier. The transfer medium is changed from N 2 to C02, thus the CO 2 concentration in the gasifier 3 is increased and the CO 2 gasification reaction shown in Formula (2) is 25 promoted. By doing this, a reduction in the use rate of - 35 02 which is a gasifying agent is expected. C + CO 2 -+ 2CO .... (2) The reduction in the 02 use rate leads not only to the equipment cost reduction due to the miniaturization 5 of the air separation unit 4 but to the running cost reduction and energy efficiency improvement due to 02 manufacture power reduction. Next, the main components in the syngas 5 generated in the gasifier 3 are CO, H2, and CO 2 . If water is 10 sprayed to the syngas 5 and is evaporated, not only the syngas 5 can be cooled but also the steam concentration in the syngas 5 is increased. By doing this, not only the shift reaction shown in Formula (1) of the first embodiment progresses but also 15 the flow rate of steam 41 added by a shift reactor 40 installed on the downstream side of the gasifier 3 which will be described later can be reduced. The present embodiment is structured, to promote the shift reaction in a high-temperature environment at 20 10000C or higher, so as to feed the high-temperature water 31 from which the solids have been separated by the solid separation portion 29 installed in the water feed system c into the syngas cooling portion 7 installed on the upper portion of the gasifier 3 via 25 the water feed system c.

- 36 For the cooling water to be sprayed to the syngas 5 on the downstream side of the gasifier 3, similarly to the case of the fourth embodiment, high-temperature water (such as the high-temperature water 15 heated by 5 the slag-cooling water pool 12, a part 37 of the cooling water of the venturi 11, or a part 38 of the cooling water of the water washing tower 13) generated in the coal gasification composite power generation plant is used. 10 So far, the sensible heat of such kinds of high temperature water has not been used validly. On the other hand, for the steam 41 added by the shift reactor 40 installed on the downstream side of the desulfurizer 17 for reacting carbon monoxide and 15 steam in the syngas 5 generated in the gasifier 3 and shift-reacting them to carbon dioxide and hydrogen, steam manufactured for the shift reaction is used. Therefore, if the flow rate of the steam 41 added to the syngas 5 by the shift reactor 40 can be reduced, 20 the power for manufacturing the reduced steam 41 can be reduced, so that it leads to the running cost reduction and energy efficiency improvement. The syngas 39 cooled to about 400C desulfurized by the desulfurizer 17 for desulfurizing the syngas 5 25 which is installed on the downstream side of the water - 37 washing tower 13 is reheated to 200 0 C or higher by the heat exchanger 42 for heating the syngas 5 after desulfurization and a syngas heater 43 and is fed to the shift reactor 40 in the syngas 5 which is installed 5 on the downstream side of the desulfurizer 17. In the shift reactor 40, the steam 41 is added to the syngas 39 after desulfurization and the shift reaction shown by Formula (1) of the first embodiment progresses. By this shift reaction, CO in the syngas 39 10 after desulfurization becomes CO 2 and H 2 and the H 2 concentration is increased. Further, the input temperature of the syngas 39 after desulfurization and the steam 41 to the shift reactor 40 is determined by the characteristics of the shift reaction catalyst. 15 The temperature of syngas 44 after the shift reaction by the shift reactor 40 is 200 0 C or higher at the exit of the shift reactor 40. Therefore, the syngas 44 after the shift reaction is cooled to about 150 0 C by the heat exchanger 42 of the syngas after 20 desulfurization and is fed to a CO 2 absorption tower 45 installed on the downstream side of the shift reactor 40. In the CO 2 absorption tower 45, the syngas 44 after the shift reaction flows into the C02 absorption tower 25 45 and makes contact with a CO 2 -absorbing liquid 47 in - 38 the CO 2 absorption tower 45. By doing this, CO 2 in the syngas 44 after the shift reaction is collected by the C0 2 -absorbing liquid 47 and becomes syngas 46 with CO 2 removed. 5 Here, the input temperature of the syngas 44 after the shift reaction to the CO 2 absorption tower 45 depends on the characteristics of the C0 2 -absorbing liquid 47. And, the main component of the syngas 46 after removal of CO 2 by the CO 2 absorption tower 45 is 10

H

2 . The syngas 46 after removal of CO 2 by the CO 2 absorption tower 45 is fed from the CO 2 absorption tower 45 to the gas turbine combustor 18 as fuel, is mixed with air for combustion fed from the compressor 24 to 15 the gas turbine combustor 18, and is burned to generate high-temperature combustion gas. The combustion gas generated by the gas turbine combustor 18 is fed to the gas turbine 19 to drive the gas turbine 19, and furthermore, the exhaust gas that 20 left the gas turbine 19 is permitted to flow down to the boiler 20, and the exhaust heat of the exhaust gas is recovered by the boiler 20 to generate steam, and the generated steam is fed to the steam turbine 21 to drive the steam turbine 21. 25 Further, a C0 2 -absorbing liquid 48 that has absorbed - 39 CO 2 from the syngas 44 by the CO 2 absorption tower 45 is heated to 100 0 C or higher by a heat exchanger 49 for the CO2-absorbing liquid and a heater 50 for the C0 2 absorbing liquid and is fed to a CO 2 regeneration tower 5 51 installed on the downstream side of the CO 2 absorption tower 45. In the CO 2 regeneration tower 51, CO 2 in the C0 2 absorbing liquid 48 containing the absorbed CO 2 is discharged, thus the C0 2 -absorbing liquid 47 can be 10 reused. As for CO 2 52 collected by the CO 2 regeneration tower 51, a part thereof, as CO 2 53 for reinput of the gasifier 3, is derived from the CO 2 regeneration tower 51 via a CO 2 feed system g and is reused for a transfer 15 medium of the coal 1 and the char 9, though the greater part of Co 2 52 collected by the CO 2 regeneration tower 51 is fed into the earth to be stored. Here, to keep the CO 2 collection rate by the CO 2 regeneration tower 51 high, the CO 2 -absorbing liquid 48 20 must be insulated thermally. Therefore, a part of the C0 2 -absorbing liquid 48 is pulled out from the CO 2 regeneration tower 51 as a C0 2 -absorbing liquid 54 for regeneration heating, is reheated to 100 0 C or higher by a heat exchanger 55, and then is input into the CO 2 25 regeneration tower 51.

- 40 The heat capacity necessary for the heat exchanger 55 is large and as a heat source therefor, it is desirable to lead and use low-temperature steam 56 of about 200 0 C to 300 0 C generated in a boiler 20 from the 5 boiler 20 to the heat exchanger 55 via a steam feed system i. The low-temperature steam 56 is called heating steam 56 for the C0 2 -absorbing liquid 54. Using the sensible heat of the heating steam 56 of the C0 2 -absorbing liquid 48, the C0 2 -absorbing liquid 54 10 for regeneration heating is reheated by the heat exchanger 55. Therefore, the heating steam 56 of the C0 2 -absorbing liquid 54 that left the heat exchanger 55 is reduced in temperature to 200 0 C or lower. As for the heating steam 56 of the C0 2 -absorbing 15 liquid 54 that left the heat exchanger 55, it is desirable to arrange a steam feed system h for feeding the heating steam 56 from the heat exchanger 55 to the downstream side of the gasifier 3, feed the heating steam 56 from the heat exchanger 55 to the downstream 20 side of the gasifier 3 via the steam feed system h, and use for cooling the syngas 5 and shift reaction promotion by the shift reactor 40. The reason is that if the heating steam 56 of the C0 2 -absorbing liquid 54 that left the heat exchanger 55 25 is returned to the steam condenser 26, the sensible - 41 heat and latent heat of the steam become waste heat. The coal gasification composite power generation plant including the gasification system for carbon containing fuel of the present embodiment is structured 5 so that four kinds of water or steam are fed to the downstream side of the gasifier 3 or the upstream side of the dust removing unit 8, the four kinds of water or steam being the steam feed system h for feeding the heating steam 56 of the C0 2 -absorbing liquid 54 that 10 left the heat exchanger 55 to the downstream side of the gasifier 3, the steam feed system i for feeding the low-temperature steam 56 from the boiler 20 to the heat exchanger 55, the water feed system c for feeding the high-temperature water 15 from the slag-cooling water 15 pool 12, and the heated water feed systems fl and f2 for feeding a part 37 of the cooling water of the venturi 11 and a part 38 of the cooling water of the water washing tower 13, so as to be used to cool the syngas 5 generated in the gasifer 3, though it is 20 possible to use a system capable of feeding water or steam of at least one kind or more among these systems. From the above-mentioned, according to the coal gasification composite power generation plant including the gasification system for carbon-containing fuel of 25 the present embodiment, a coal gasification composite - 42 power generation plant having a high energy efficiency without discharging C02 can be constructed. Also, in the coal gasification composite power generation plant including the gasification system for 5 carbon-containing fuel of the present embodiment, as an example of the CO 2 collection means, the system using a C02 chemical absorption system that uses the CO 2 absorbing liquid 54 has been explained. Further, for the C02 collection means, a physical 10 absorption system such as film separation and an adsorption agent system may be used. According to the present embodiment, a gasification system for carbon-containing fuel which not only efficiently uses the exhaust heat of high-temperature 15 water to cool the syngas that left the gasifier but also collects the solids in the high-temperature water by the dust removing unit of the existing gasifier to enable reinput into the gasifier and thereby reduce the carbon loss and waste matter generated from the carbon 20 containing fuel can be achieved. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to 25 imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or - 43 steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be 5 taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 10

Claims

1. A gasification system for carbon-containing fuel comprising: 5 a gasifier for gasifying carbon-containing solid fuel and generating syngas, and a fuel feed system for transferring the carbon containing solid fuel from a coal hopper into the gasifier by gas, wherein: 10 the gasifier is structured so as to take out the syngas generated by gasifying the carbon containing fuel from above the gasifier, convert inorganic material included in the carbon containing fuel to fused slag, and take it out 15 below the gasifier, and the gasification system further comprising: a dust removing part installed on a downstream side of the gasifier for removing dust from the syngas taken out from above the 20 gasifier, a char hopper for collecting char from which dust removed by the dust removing part and is accompanied with the syngas, a char feed system for transferring 25 the char collected by the char hopper from the - 45 char hopper to the gasifier by gas, a water washing tower installed on a downstream side of the dust removing part for washing the syngas flowing down through the 5 dust removing part, a slag-cooling water pool installed on a bottom of the gasifier for cooling the fused slag with cooling water fed from outside, and 10 a water feed system for feeding high temperature water raised in temperature by the fused slag in the slag-cooling water pool from the slag-cooling water pool to the downstream side of the gasifier and to an upstream side 15 of the dust removing part to cool the syngas taken out from the gasifier.

2. The gasification system for carbon-containing fuel according to Claim 1, comprising a solid feed 20 system for transferring solids collected by a solid separation portion to the gasifier.

3. The gasification system for carbon-containing fuel according to Claim 1, comprising: 25 a solid feed system for feeding solids collected by - 46 a solid separation portion to the char hopper, wherein the solid fed to the char hopper via the solid feed system is inputted into the gasifier via the char feed system. 5

4. The gasification system for carbon-containing fuel according to any one of Claims 1 to 3, comprising: a venturi and a water washing tower installed on the downstream side of the dust removing part for 10 cooling the syngas taken out from the gasifier due to gas-liquid contact with cooling water, and a heated water feed system for feeding a part of cooling water of the venturi and a part of cooling water of the water washing tower which are heated by 15 contact with the syngas taken out from the gasifier in the venturi and the water washing tower from the venturi and the water washing tower to the downstream side of the gasifer or the upstream side of the dust removing part and cooling the syngas taken out from the 20 gasifier.

5. The gasification system for carbon-containing fuel according to Claim 1, comprising: the water washing tower installed on the downstream 25 side of the dust removing part for washing the syngas - 47 flowing down through the dust removing part, a desulfurizer installed on a downstream side of the water washing tower for desulfurizing the syngas flowing down through the water washing tower, 5 a CO 2 absorption tower installed on the downstream side of the desulfurizer for absorbing CO 2 in the syngas flowing down through the desulfurizer into an absorbing liquid, and a CO 2 regeneration tower for heating the CO 2 10 absorbing liquid absorbed the CO 2 to separate the CO 2 and regenerating the absorbing liquid, wherein: a CO 2 feed system for feeding the CO 2 from the CO 2 regeneration tower to the coal hopper so as to transfer the carbon-containing solid fuel to the 15 gasifier by the CO 2 separated in the CO 2 regeneration tower.

6. The gasification system for carbon-containing fuel according to Claim 5, comprising a steam feed 20 system for feeding steam used as a heat source for the C0 2 -absorbing liquid for regeneration and heating pulled out from the CO 2 regeneration tower to the downstream side of the gasifier or the upstream side of the dust removing part and cooling the syngas.