AU2011242111A1 - Operational method for coal gasification reaction furnace and coal gasification reaction furnace - Google Patents

Abstract

Disclosed is an operational method for a coal gasification reaction furnace comprising a lower reaction vessel and an upper reaction vessel communicating with each other, which includes the following steps: a step wherein carbon raw material, oxygen gas and water vapour are supplied inside the lower reaction vessel; a step wherein coal is supplied using a coal nozzle, and water vapour is supplied using a water nozzle, inside the upper reaction vessel; a step wherein the coal in the upper reaction chamber is reacted at a temperature of 950°C or higher by the high-temperature gas produced in the lower reaction vessel and a synthesis gas containing at least hydrogen gas and carbon monoxide gas is produced; and a step wherein the mass flow rate of the coal supplied by the coal nozzle and/or the mass flow rate of the water vapour supplied by the water vapour nozzle are adjusted such that the ratio of mass flow rate (Qs) of the water vapour content of the synthesis gas and mass flow rate (Qc) of the carbon supplied to the upper reaction vessel, Qs/Qc, is 1.0-1.5.

Description

DESCRIPTION OPERATIONAL METHOD FOR COAL GASIFICATION REACTION FURNACE AND COAL GASIFICATION REACTION FURNACE 5 TECHNICAL FIELD [0001] The present invention relates to a coal gasification reaction furnace in which coal is gasified by oxidizing agents such as oxygen gas, steam, and the like to produce a 10 combustible gas, and the like, and the present invention also relates to a method for operating the coal gasification reaction furnace. The present application claims priority on Japanese Patent Application No. 2010-095498 filed on April 16, 2010, the content of which is incorporated herein by reference. 15 BACKGROUND ART [0002] There has been considered a gasification furnace having various constitutions such as a fixed bed, a fluid bed, an entrained bed (air jet bed), and the like for gasifying 20 coal to efficiently produce a combustible gas, and the like. Among them, an entrained bed gasification furnace is easily increased in capacity and high in load following characteristics, particularly when the use of generating electric power is taken into account. For these reasons, in recent years, the entrained bed gasification furnace has been used mainly as a gasification furnace. 25 [0003] 2 In an entrained-bed gasification furnace, coal is thermally decomposed to generate char (coal residue not yet gasified or thermally decomposed residue), coal tar, and the like, which mainly include carbon. In order to decrease an amount of the char by gasification reactions, there is proposed a gasification furnace (coal gasification reaction 5 furnace) having a two-tier of two-chamber structure which includes a high-temperature gasification furnace (lower reaction vessel) installed as a lower chamber and a thermal-decomposition gasification reaction furnace (upper reaction vessel) installed as an upper chamber (refer to Patent Document 1, for example). In this gasification furnace, coal, oxygen gas, and steam are supplied at a 10 predetermined ratio to the high-temperature gasification furnace which is kept high in temperature and pressure; and thereby, the coal is thermally decomposed to produce char, coal tar, and the like, which mainly include carbon. Furthermore, steam is supplied into the thermal-decomposition gasification reaction furnace of the gasification furnace; and thereby, the char is gasified to reduce a production quantity of char, as shown in the 15 chemical equation (1) described below. [0004] C (char)+ H 2 0 - CO + H2 (1) PRIOR ART DOCUMENT 20 Patent Document [00051 Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2002-155289 25 DISCLOSURE OF THE INVENTION 3 Problems to be Solved by the Invention [0006] However, in a gasification furnace disclosed in Patent Document 1, highly viscous coal tar is generated from coal together with char, and the coal tar adheres on an 5 inner surface of a thermal-decomposition gasification reaction furnace (actually, a carbonaceous substance derived from coal tar adheres on the inner surface). The generated coal tar reacts with steam supplied into the thermal-decomposition gasification reaction furnace and is gasified as shown in the above chemical equation (1). However, since an excessive amount of steam is supplied into the thermal-decomposition 10 gasification reaction furnace, an amount of coal and the like to be fed into the thermal-decomposition gasification reaction furnace is decreased; and thereby, a quantity of a combustible gas produced in the gasification furnace is reduced. This poses a problem. [0007] 15 The present invention has been made in view of the above problems, an object thereof is to provide a coal gasification reaction furnace which is capable of effectively preventing the increasing of an adhesion amount of coal tar inside an upper reaction vessel without greatly reducing a production quantity of a combustible gas and a method for operating the coal gasification reaction furnace. 20 Means for Solving the Problems [0008] In order to attain the above-described object, the method for operating a coal gasification reaction furnace according one aspect of the present invention is a method for 25 operating a coal gasification reaction furnace having a lower reaction vessel and an upper 4 reaction vessel which are communicatively connected with each other. The method includes the following steps: a step in which a carbonaceous material, oxygen gas, and steam are supplied into the lower reaction vessel; 5 a step in which coal is supplied by a coal nozzle and steam is supplied by a steam nozzle into the upper reaction vessel; a step in which the coal inside the upper reaction vessel is reacted at a temperature of 950*C or higher by using a high-temperature gas generated inside the lower reaction vessel, and thereby a synthesis gas is produced which contains at least hydrogen 10 gas and carbon monoxide gas; a step in which a mass flow rate of steam Qs contained in the synthesis gas is determined; a step in which a mass flow rate of carbon Qc supplied to the upper reaction vessel is determined on the basis of a carbon content of the coal; and 15 a step in which at least one of the mass flow rate of the coal supplied by the coal nozzle and the mass flow rate of the steam supplied by the steam nozzle is adjusted in such a manner that a ratio Qs/Qc of the mass flow rate of the steam Qs to the mass flow rate of the carbon Qc becomes in a range of 1.0 or more to 1.5 or less. [0009] 20 According to the above operation method, the ratio Qs/Qc is set to be in a range of 1.0 or more; and thereby, steam is supplied at an amount sufficient to gasify coal tar generated by thermal decomposition of coal in the lower reaction vessel and the upper reaction vessel. Therefore, it is possible to effectively prevent the increasing of an adhesion amount of coal tar inside the upper reaction vessel. In addition, the ratio Qs/Qc 25 is set to be in a range of 1.5 or less; and thereby, it is possible to prevent the supplying of 5 an excessive amount of stream into the upper reaction vessel. As a result, it is possible to prevent the greatly decreasing of a production quantity of a synthesis gas. [0010] In the method for operating the coal gasification reaction furnace according to 5 one aspect of the present invention, a lower reaction vessel and an upper reaction vessel are used. The lower reaction vessel has an accommodation space internally, and the upper reaction vessel is installed above the lower reaction vessel and includes a through hole communicatively connected to the accommodation space of the lower reaction vessel via a diameter reduced portion and extending in a vertical direction. A carbonaceous 10 material, oxygen gas and steam are supplied at a predetermined ratio into the lower reaction vessel. Coal and steam are supplied to the upper reaction vessel. Then, the coal is reacted at a temperature of 950*C or higher in the upper reaction vessel by using sensible heat of a high-temperature gas from the lower reaction vessel; and thereby, at least hydrogen gas and carbon monoxide gas are produced. In the above-described 15 method for operating the coal gasification reaction furnace, a mass flow rate of at least one of the coal and the steam supplied into the upper reaction vessel is adjusted in such a manner that a ratio of a mass of the steam contained in a fluid which flows per unit time from an outlet of the through hole of the upper reaction vessel to a mass of carbon contained in the coal which is supplied per unit time to the upper reaction vessel becomes 20 in a range of 1.0 or more to 1.5 or less. As the above-described carbonaceous material, it is possible to use a carbon-containing solid material such as coal, char, and the like. [0011] Coal tar is generated by thermal decomposition of coal in the lower reaction 25 vessel and the upper reaction vessel of the coal gasification reaction furnace. A mass 6 flow rate of carbon in coal supplied per unit time to the upper reaction vessel is given as Qc, and a mass flow rate of steam contained in a fluid that flows per unit time from an outlet of the through hole of the upper reaction vessel is given as Qs. The ratio Qs/Qc is referred to as a "mass ratio of steam to carbon (steam/carbon)". A mass flow rate of at 5 least one of coal and steam supplied to the upper reaction vessel is adjusted in such a manner that the mass ratio of steam to carbon becomes in a range of 1.0 or more to 1.5 or less. At this time, since reactions take place at a temperature of 950*C or higher in the upper reaction vessel, coal tar is more likely to undergo gasification reactions. [0012] 10 The inventors have found that in the case where the mass ratio of steam to carbon is adjusted to be 1.0, a balance is developed between a quantity of coal tar adhered on an inner circumference surface of the through hole of the upper reaction vessel and a removal quantity of coal tar which adheres in advance inside the through hole and turns into carbon monoxide by reactions with steam. 15 Not only steam which is directly supplied into the upper reaction vessel but also steam which is generated from heated coal supplied into the upper reaction vessel and steam which flows from the accommodation space of the lower reaction vessel as a gas are supplied into the upper reaction vessel. The above-described steam reacts with carbon and is decomposed into carbon monoxide gas and hydrogen gas. In this instance, a state 20 in which the mass ratio of steam to carbon is 1.0 is such a state that excessive steam not consumed by reactions with carbon is present at a certain quantity in the upper reaction vessel. [0013] As described above, the mass ratio of steam to carbon is set to be 1.0 or more; 25 and thereby, it is possible to effectively prevent the increasing of an adhesion amount of 7 coal tar inside the upper reaction vessel. Furthermore, the mass ratio of steam to carbon is adjusted to be 1.5 or less; and thereby, it is possible to prevent the supplying of an excessive amount of stream into the upper reaction vessel and to prevent the decreasing of a production quantity of a combustible gas. 5 [0014] Furthermore, in the method for operating the coal gasification reaction furnace, there may be determined a mass of the steam contained in a fluid which flows per unit time from an outlet of the through hole of the upper reaction vessel, as follows. That is, a mass flow rate of the fluid which flows per unit time is measured. A concentration of 10 steam contained in the fluid is measured. Then, a product of a measured value of the mass flow rate and a measured value of the concentration of the steam is given as a mass of the steam contained in the fluid which flows per unit time. According to the above-described method, it is possible to easily determine a mass of steam contained in a fluid which flows per unit time from an outlet of the through 15 hole. [0015] Furthermore, in the above-described method for operating the coal gasification reaction furnace, steam may be supplied into the upper reaction vessel, as follows. First, a difference in pressure is measured between either one of a portion below a coal nozzle of 20 supplying the coal in the through hole of the upper reaction vessel or the accommodation space of the lower reaction vessel and an upper end portion of the through hole. Then, when the difference in pressure exceeds a predetermined value, a predetermined quantity of steam is supplied into the upper reaction vessel. According to the above method, it is possible to prevent more reliably the through 25 hole of the upper reaction vessel from being clogged by coal tar.

8 [0016] The coal gasification reaction furnace according to one aspect of the present invention is a coal gasification reaction furnace which is used in the above-described operation method. The coal gasification reaction furnace includes: a lower reaction 5 vessel which has an accommodation space internally; and an upper reaction vessel which is installed above the lower reaction vessel. The lower reaction vessel includes a gasification burner which supplies a carbonaceous material, oxygen gas, and steam at a predetermined ratio into the lower reaction vessel to burn the carbonaceous material. The upper reaction vessel includes: a through hole which is communicatively connected to 10 the accommodation space of the lower reaction vessel via a diameter reduced portion and extends in a vertical direction; a coal nozzle which supplies coal to the interior; a steam nozzle which supplies steam to the interior; and a moisture meter which is installed at an upper end portion of the through hole to measure a mass of steam flowing per unit time from the end portion of the through hole. 15 [0017] In the lower reaction vessel and the upper reaction vessel of the coal gasification reaction furnace, coal tar is generated by thermal decomposition of coal. In the upper reaction vessel, coal tar reacts with steam at a temperature of 950"C or higher. Furthermore, the moisture meter measures a mass of steam flowing per unit time from the 20 upper end portion of the through hole. Then, at least one of the coal nozzle and the steam nozzle is controlled in such a manner that the mass ratio of steam to carbon is set to be in a range of 1.0 or more to 1.5 or less. Thereby, it is possible to maintain a production quantity of a combustible gas and also effectively prevent the increasing of an adhesion amount of coal inside the upper reaction vessel. 25 [0018] 9 Furthermore, the above-described coal gasification reaction furnace may include a first piping, a second piping, and a pressure meter. The first piping is connected to a portion below the coal nozzle on the through hole of the upper reaction vessel or the accommodation space of the lower reaction vessel. The second piping is connected to 5 the upper end portion of the through hole of the upper reaction vessel. The pressure meter measures a difference in pressure between the first piping and the second piping. The inventors have found that coal tar generated by thermal decomposition of coal adheres in a concentrated manner at a certain position above the coal nozzle in the through hole of the upper reaction vessel. 10 On the basis of this finding, the first piping is connected to a portion below the nozzle portion on the through hole of the upper reaction vessel at which coal tar is less likely to adhere or the accommodation space of the lower reaction vessel, and the second piping is connected to the upper end portion of the through hole. Thereby, it is possible to prevent adhesion of coal tar to the piping, and it is possible to measure a difference in 15 pressure accurately. Effects of the Invention [0019] According to the coal gasification reaction furnace and the method for operating 20 the coal gasification reaction furnace of the above aspects, it is possible to maintain a production quantity of a combustible gas and it is also possible to effectively prevent the increasing of an adhesion amount of coal tar inside the upper reaction vessel. BRIEF DESCRIPTION OF THE DRAWINGS 25 [0020] 10 Fig. I is a block diagram which shows a coal gasification system including a coal gasification reaction furnace according to a first embodiment of the present invention. Fig. 2 is a schematic diagram which shows a cross section of the coal gasification reaction furnace. 5 Fig. 3 is a graph which shows changes in individual values with respect to a mass ratio of steam to carbon in the coal gasification reaction furnace. Fig. 4 is a schematic diagram which shows a cross section of a coal gasification reaction furnace which according to a second embodiment of the present invention. Fig. 5 is a graph which shows changes in difference in pressure with respect to 10 elapsed time during operation of the coal gasification reaction furnace. BEST MODE FOR CARRYING OUT THE INVENTION [0021] (First Embodiment) 15 Hereinafter, an explanation will be made for the coal gasification reaction furnace according to a first embodiment of the present invention while referring to Fig. I to Fig. 3. The coal gasification reaction furnace of the present embodiment is a part of a coal gasification system and an apparatus which bums coal internally to produce at least hydrogen gas and carbon monoxide gas. 20 As shown in Fig. 1, a coal gasification system I is a plant in which a synthesis gas mainly including hydrogen gas and carbon monoxide gas is synthesized from coal as a raw material, and products such as methane, methanol, ammonia, and the like are finally produced from the synthesis gas. The coal gasification system 1 includes a coal grinding and drying equipment 2, a 25 coal supplying equipment 3, a coal gasification reaction furnace 4, a heat recovery equipment 5, a char recovery equipment 6, a shift reaction equipment 7, a gas purification equipment 8, a chemical synthesis equipment 9, and an air separation equipment 10. [0022] In general, an outer diameter of coal is not uniform, and coal may contain 5 moisture at a content greater than a desired content, depending on its type. Thus, at first, in the coal grinding and drying equipment 2, coal is ground into particles having a particle size (outer diameter) of, for example, approximately 10pm or more to 100pm or less. The thus ground coal is further dried so as to have a predetermined moisture content, and thereafter, the coal is supplied into the coal supplying equipment 3. During a period 10 from a time when coal is discharged from the coal grinding and drying equipment 2 to a time when the coal is fed into the coal gasification reaction furnace 4, the coal moves inside a sealed space so that a moisture content of the dried coal will not change. Then, the coal is mixed with a carrier gas inside the coal supplying equipment 3 so as to be supplied into the coal gasification reaction furnace 4 and the mixture is 15 pressurized up to a predetermined pressure. Thereafter, the mixture is carried to the coal gasification reaction furnace 4 by conveyance. From a gasification burner 17 of the coal gasification reaction furnace 4 which will be described below, not only coal but also a solid material containing carbon such as char and the like are supplied by a supply device (not illustrated). In the following, the solid material containing carbon such as coal, char, 20 and the like is referred to as a "carbonaceous material." The air separation equipment 10 liquefies air by compression; and thereby, dried oxygen gas and nitrogen gas are separated from the liquefied air by utilizing a difference in boiling point. The oxygen gas separated by the air separation equipment 10 is supplied to the coal gasification reaction furnace 4. 25 [0023] 12 As shown in Fig. I and Fig. 2, the coal gasification reaction furnace 4 includes: a partial oxidation unit (lower reaction vessel) 11 having an accommodation space 11 a internally; and a thermal decomposition unit (upper reaction vessel) 13 installed at Dl above the partial oxidation unit 11. The thermal decomposition unit 13 includes a 5 through hole (tubular part) 12 which is communicatively connected via a diameter reduced portion I3a to the accommodation space I I a of the partial oxidation unit 11 and extends in a vertical direction D. The coal gasification reaction furnace 4 is made with, for example, heat-resistant bricks. Since the diameter reduced portion 13a is provided, it is possible to operate the 10 partial oxidation unit 1I and the thermal decomposition unit 13 under mutually independent reaction conditions. A slag cooling water tank 14 is installed at D2 below the partial oxidation unit 11 in a perpendicular direction. The partial oxidation unit II is communicatively connected to the slag cooling water tank 14 in the vertical direction (perpendicular direction) D. A 15 second diameter reduced portion 14a is formed at a portion which connects the partial oxidation unit I1 to the slag cooling water tank 14. [0024] As shown in Fig. 2, the partial oxidation unit 11 is formed approximately in a cylindrical shape extending in the vertical direction D. A plurality of gasification burners 20 17 formed in a cylindrical shape extending along a predetermined axis line Cl are installed on an inner circumference surface of the partial oxidation unit 11. Each of the gasification burners 17 is connected to the coal supplying equipment 3, the air separation equipment 10 and the heat recovery equipment 5 which generates steam by a method described below, as shown in Fig. 1. The gasification burner 17 is capable of supplying a 25 carbonaceous material, oxygen gas, and steam (hereinafter, referred to as "a carbonaceous 13 material, and the like") at a predetermined ratio to the partial oxidation unit 11. The gasification burner 17 is arranged in such a manner that a leading end side of the axis line Cl thereof faces obliquely downward with respect to a horizontal plane and the axis line Cl is positioned to be tilted with respect to a center axis line C2 of the partial oxidation 5 unit 11. Furthermore, a cooling device (not illustrated) is installed on an outer circumference surface of the partial oxidation unit 11; and thereby, it is possible to cool the partial oxidation unit 1I which is heated by burning of coal. [0025] 10 The thermal decomposition unit 13 is formed approximately in the shape of a pipe extending in the vertical direction D and an inner diameter thereof is set to be smaller than an inner diameter of the partial oxidation unit 11. A plurality of coal nozzles 18 which supply coal to the thermal decomposition unit 13 are installed at an intermediate portion of the thermal decomposition unit 13 in the 15 vertical direction D, and a single steam nozzle 19 which supplies steam to the thermal decomposition unit 13 is installed at D2 below the coal nozzles 18. Each of the coal nozzles 18 is connected to the coal supplying equipment 3, and the steam nozzle 19 is connected to the heat recovery equipment 5. The number of the coal nozzles 18 and that of the steam nozzle 19 are not 20 restricted and any number is acceptable. [0026] An upper end portion (outlet) 12a of the through hole 12 of the thermal decomposition unit 13, which is Dl, is connected to the heat recovery equipment 5. A moisture meter 20 is provided at the end portion 12a of the through hole 12 of 25 the thermal decomposition unit 13. The meter measures a mass of steam flowing per unit 14 time (for example, per hour) from the end portion 12a of the through hole 12. The moisture meter 20 can be constituted by known technologies in combination of a flow meter which measures a mass flow rate of a synthesis gas flowing per unit time from the end portion 12a of the through hole 12, an element analyzer which measures a 5 percentage of steam contained in the synthesis gas (concentration of steam), and the like. The mass of steam flowing per unit time (mass flow rate of Qs) can be determined, for example, from a product of a value obtained by measuring the mass flow rate of the synthesis gas by the flow meter and a value of the concentration of the steam measured by the element analyzer and the like. 10 [0027] A predetermined quantity of water W is accommodated in the slag cooling water tank 14. The slag cooling water tank 14 cools slag which falls down from the partial oxidation unit 11, as will be described below. [0028] 15 Next, an explanation will be made for the method for operating the coal gasification reaction furnace 4. At first, the gasification burners 17 are used to supply a carbonaceous material and the like including granular coal at a predetermined flow rate into the partial oxidation unit 11. Each of the gasification burners 17 is positioned to be tilted with respect to the 20 axis line C2 as described above. Therefore, the carbonaceous material and the like supplied from each of the gasification burners 17 rotate spirally, moving downward to D2 around the center axis line C2 of the partial oxidation unit 11. At this time, the inside of the partial oxidation unit 1 is kept at a high temperature, for example, in a range of 1300*C or higher to 1700*C or less and at a high pressure in a range of 2 MPa or more to 3 25 MPa or less. Under such a condition, a temperature of the carbonaceous material 15 becomes high, and the carbonaceous material is thermally decomposed. Thereby, char is separated from a volatile gas containing coal tar, steam, and the like. Furthermore, the carbonaceous material burns to effect chemical reactions as shown by chemical equations (2) to (4) described below. Thereby, high-temperature carbon monoxide gas, carbon 5 dioxide gas, hydrogen gas, and slag (ash) are generated. [0029] 2C + 02 - 2CO -- (2) C +0 2 - C0 2 (3) C+ H 2 0 - CO+ H 2 (4) 10 [0030] A temperature of a gas, slag, and the like generated inside the partial oxidation unit I1 becomes high by heat generated during a carbonaceous material burns and the gas, slag, and the like are expanded; and thereby, they receive an ascending force toward Dl above. Then, they ascend inside the partial oxidation unit 11, while swirling. 15 Slag generated inside the partial oxidation unit I1 is in a melted state. Some portion of the slag is cooled by the cooling device on an inner circumference surface of the partial oxidation unit 1 and adheres on the inner circumference surface. The other portion of the slag falls down into the water W inside the slag cooling water tank 14 installed below the partial oxidation unit 11 to be cooled and is recovered. 20 [0031] A gas such as high-temperature steam, coal tar, char, and the like generated inside the partial oxidation unit 11 move from the partial oxidation unit 11 and ascend inside the thermal decomposition unit 13. In the present embodiment, a temperature of the inside of the thermal decomposition unit 13 is adjusted to be in a range of 950 0 C or higher. In 25 the case where the temperature inside the thermal decomposition unit 13 is lower than 16 950'C, a generation amount of coal tar is increased rapidly, and in addition, the coal tar is less likely to undergo decomposition reactions. At this time, coal is supplied from the coal nozzles 18 and steam is supplied from the steam nozzle 19, respectively. An operator adjust a supply amount of at least one of 5 the coal and steam in the following manner. That is, a mass of carbon contained in coal which is supplied to the thermal decomposition unit 13 per unit time (for example, per hour) from all the coal nozzles 18 is given as Qc. Furthermore, a mass of steam contained in a fluid which flows from the end portion 12a of the through hole 12 per unit time (for example, per hour) is given as Qs. A ratio of Qs to Qc (Qs/Qc), that is, a mass 10 ratio of steam to carbon (steam/carbon) is adjusted to be 1.0 or more to 1.5 or less. Steam which is supplied into the thermal decomposition unit 13 includes not only steam supplied from the steam nozzle 19 but also steam flowing from the accommodation space I I a of the partial oxidation unit 1I and steam derived from evaporation of moisture contained in coal. Therefore, the steam supplied to the thermal decomposition unit 13 is 15 adjusted on the basis of a quantity of steam flowing from the end portion 12a of the through hole 12. The steam supplied to the thermal decomposition unit 13 reacts with carbon to produce carbon monoxide gas and hydrogen gas. A state in which the mass ratio of steam to carbon is 1.0 is such a state that excessive steam which will not react with carbon yet is present in a certain quantity in the thermal decomposition unit 13. 20 [0032] The above-described mass ratio of steam to carbon is adjusted, for example, by the following manner. First, the moisture meter 20 is used to measure a mass of steam which is contained in a gas flowing per unit time from the end portion 12a of the through hole 12 of the thermal decomposition unit 13. For example, in the case where a 25 measured value of a mass flow rate of steam Qs is 100 (kg/h) and the mass ratio of steam 17 to carbon is set to be 1.0 or more, a mass flow rate of coal supplied from all the coal nozzles 18 to the thermal decomposition unit 13 is adjusted so that a mass flow rate of carbon Qc supplied to the thermal decomposition unit 13 becomes in a range of 100 (kg/h) or less. In other words, in the case where two coal nozzles 18 are installed, a mass flow 5 rate of coal supplied from each of the coal nozzles 18 to the thermal decomposition unit 13 is adjusted in such a manner that a mass flow rate of carbon Qc supplied from each of the coal nozzles 18 to the thermal decomposition unit 13 becomes in a range of, for example, 50 (kg/h) or less. In this instance, the carbon content of coal supplied to the thermal decomposition 10 unit 13 is measured in advance to understand a relationship between the mass flow rate of coal and the mass flow rate of carbon Qc. Thereby, it is possible to determine the mass flow rate of coal necessary for setting the mass ratio of steam to carbon to be in a range of 1.0 to 1.5. Furthermore, there is a case where the supply of coal from the coal nozzles 18 15 may change the mass flow rate of steam Qs which is measured by the moisture meter 20. In this case, the mass flow rate of coal to be supplied is adjusted, and the mass flow rate of steam Qs contained in a synthesis gas is measured again by the moisture meter 20. Then, the adjusting of the mass flow rate of coal and the measuring of the mass flow rate of steam Qs are repeatedly conducted so as to maintain a predetermined mass ratio of steam 20 to carbon. In this embodiment, only the mass flow rate of coal is adjusted. However, it is acceptable that the mass flow rate of steam supplied from the steam nozzle 19 to the accommodation space I I a of the partial oxidation unit 11 is adjusted depending on conditions. It is also acceptable that not only the mass flow rate of coal is adjusted but 25 also the mass flow rate of steam is adjusted which is supplied from the gasification burner 18 17 to the accommodation space 1 la of the partial oxidation unit 11. Furthermore, it is acceptable that, while the mass flow rate of coal is kept constant, the mass flow rate of steam is adjusted which is supplied from the steam nozzle 19 or the gasification burner 17 to the accommodation space 1 a of the partial oxidation unit 11. 5 [0033] When a mass flow rate of coal supplied from the coal nozzle 18 is to be increased, a mass flow rate of steam supplied from the steam nozzle 19 is to an appropriate value. Then, after reactions become stable inside the thermal decomposition unit 13, the moisture meter 20 is used to measure the mass flow rate of steam Qs 10 contained in a synthesis gas. Thereafter, the mass flow rate of coal supplied from the coal nozzle 18 may be adjusted so as to meet the above mass ratio of steam to carbon. Furthermore, the moisture meter 20 can be replaced by various types of meters, for example, a dew point hygrometer. 15 [0034] Conventionally, there is a case where a portion of coal tar generated in the partial oxidation unit 11 and a portion of coal tar generated by thermal decomposition of carbon that is supplied from the coal nozzle 18 turn into an adhesive carbonaceous substance inside the through hole 12 of the thermal decomposition unit 13 and the carbonaceous 20 substance adheres on an inner circumference surface of the through hole 12. However, in the present embodiment, a mass ratio of steam to carbon supplied into the thermal decomposition unit 13, a ratio of Qs to Qc, is adjusted as described above. Therefore, coal tar which would conventionally adhere on an inner circumference surface of the through hole 12 of the thermal decomposition unit 13 turns into a gas as shown in 25 the chemical equation (5) described below and the gas flows out from the thermal 19 decomposition unit 13. [0035] C (coal tar)+ H 2 0 - CO + H 2 (5) [0036] 5 Fig. 3 is a graph which shows a relationship between a change in the mass ratio of steam to carbon, an increasing rate of an adhesion amount of coal tar and a change in energy efficiency. The mass ratio of steam to carbon is shown on the horizontal axis, the increasing rate of the adhesion amount of coal tar inside the through hole 12 of the thermal decomposition unit 13 is shown on the left-side vertical axis, and the energy efficiency is 10 shown on the right-side vertical axis. In this instance, the energy efficiency is a ratio of the following two heating values. That is, a ratio of heating values of a carbonaceous material and coal supplied from the gasification burners 17 of the partial oxidation unit 11 and the coal nozzles 18 of the thermal decomposition unit 13 to heating values of gases such as hydrogen, carbon monoxide, and the like and oil obtained in the coal gasification 15 reaction furnace 4. In the case where the mass ratio of steam to carbon is greater than 1.0, the increasing rate of an adhesion amount of coal tar that is indicated by the solid line LI in Fig. 3 is a negative value, and an amount of coal tar adhered on an inner circumference surface of the thermal decomposition unit 13 is decreased. On the other hand, in the case 20 where the mass ratio of steam to carbon is smaller than 1.0, the increasing rate of an adhesion amount of coal tar is a positive value, and an amount of coal tar adhered on the inner circumference surface of the thermal decomposition unit 13 is increased. The greater the mass ratio of steam to carbon is, the more easily coal tar adhered on the thermal decomposition unit 13 is removed as shown in the above chemical equation 25 (5). However, an excessive quantity of steam will lower a temperature inside the thermal 20 decomposition unit 13; and thereby, an amount of a carbonaceous material which can be fed into the thermal decomposition unit 13 is decreased. Therefore, the energy efficiency indicated by the dashed line L2 in Fig. 3 is decreased. In order not to unnecessarily decrease the energy efficiency, it is preferable that the mass ratio of steam to carbon is set 5 to be in a range of 1.0 or more to 1.5 or less. In the case where higher energy efficiency is needed, the mass ratio of steam to carbon may be set to be in a range of 11.0 or more to 1.1 or less. Furthermore, a protion of carbon contained in coal supplied into the thermal decomposition unit 13 reacts with carbon dioxide gas inside the thermal decomposition 10 unit 13 and turns into carbon monoxide gas as shown by the chemical equation (6) described below. [0037] C + C02 - 2CO (6) [0038] 15 Then, as shown in Fig. 1, a high-temperature synthesis gas mainly including hydrogen gas and carbon monoxide gas is conveyed together with char from above the thermal decomposition unit 13 and supplied to the heat recovery equipment 5. In the heat recovery equipment 5, the synthesis gas conveyed from the thermal decomposition unit 13 is subjected to heat exchange with steam to heat the steam. This 20 steam is supplied to the coal grinding and drying equipment 2, the coal gasification reaction furnace 4, and the like, for the purpose of drying coal or other purposes. The synthesis gas cooled by the heat recovery equipment 5 is supplied from the heat recovery equipment 5 to the char recovery equipment 6. In the char recovery equipment 6, char contained in the synthesis gas is recovered. 25 The synthesis gas which has passed through the char recovery equipment 6 is 21 supplied into the shift reaction equipment 7. Steam is supplied into the shift reaction equipment 7 for increasing a ratio of an amount of hydrogen gas to an amount of carbon monoxide gas in the synthesis gas up to a certain value. Then, carbon dioxide gas and hydrogen gas are generated from carbon monoxide gas and steam in the synthesis gas by 5 the shift reaction shown by the chemical equation (7) described below. [0039] CO + H 2 0 - C0 2 + H 2 (7) [0040] Components of the synthesis gas have been adjusted by the shift reaction 10 equipment 7, and then the synthesis gas is supplied to the gas purification equipment 8 to recover carbon dioxide gas, a gas containing sulfur as a component, and the like which are contained in the synthesis gas. The synthesis gas purified by the gas purification equipment 8 is supplied into the chemical synthesis equipment 9 to produce products such as methane, methanol, and the 15 like. [0041] As described above, in the coal gasification reaction furnace 4 and the method for operating the coal gasification reaction furnace 4 in the present embodiment, a mass flow rate of at least one of coal and steam supplied to the thermal decomposition unit 13 is 20 adjusted in such a manner that the mass ratio of steam to carbon becomes in a range of 1.0 or more to 1.5 or less. The inventors have found that the mass ratio of steam to carbon is adjusted to be 1.0; and thereby, a balance is developed between a quantity of coal tar adhered inside the through hole 12 of the thermal decomposition unit 13 and a removed quantity of coal tar 25 which adheres in advance on the through hole 12 and turns into carbon monoxide by 22 reactions with steam, as shown by the above chemical equation (5). On the basis of this finding, the mass ratio of steam to carbon is set to be 1.0 or more in the above embodiment. Thereby, even in the case where coal tar is generated by thermal decomposition of coal in the partial oxidation unit I1 and the thermal 5 decomposition unit 13, it is possible to effectively prevent the increasing of an adhesion amount of coal tar inside the through hole 12 of the thermal decomposition unit 13. Furthermore, the mass ratio of steam to carbon is adjusted to be 1.5 or less; and thereby, it is possible to prevent the supplying of an excessive amount of stream into the thermal decomposition unit 13 and to prevent the decreasing of a production quantity of a 10 combustible gas such as hydrogen gas and the like. [0042] In the above-described embodiment, when determining a mass of steam contained in a fluid which flows per unit time from the end portion 12a of the through hole 12 of the thermal decomposition unit 13, a mass flow rate of the fluid which flows per unit time is 15 measured, and a concentration of steam contained in the fluid is also measured. Then, a product of a measured value of the mass flow rate and a measured value of the concentration of steam is used as a mass of steam contained in the fluid which flows per unit time. Therefore, it is possible to easily determine a mass of steam contained in a fluid 20 which flows per unit time from the end portion 12a of the through hole 12. [0043] (Second Embodiment) Next, an explanation will be made for a second embodiment of the present invention. Hereinafter, the same reference numerals will be given to the same parts as 25 those of the first embodiment, and an explanation thereof will be omitted here. An 23 explanation will be made only for points different from the First Embodiment. As shown in Fig. 4, a coal gasification reaction furnace 31 of the present embodiment includes a pressure meter 32 for measuring a difference in pressure of a thermal decomposition unit 13, together with individual constitutions of the coal 5 gasification reaction furnace 4 of the first embodiment. [0044] The pressure meter 32 includes: a first piping 33 connected so as to be communicatively connected to an accommodation space 11 a of a partial oxidation unit 11; a second piping 34 connected so as to be commutatively connected to an end portion 12a 10 of a through hole 12 of the thermal decomposition unit 13; and a main body 35 for measuring a difference in pressure between an internal pressure of the first piping 33 and an internal pressure of the second piping 34. [0045] When the thus constituted coal gasification reaction furnace 31 is operated, an 15 operator adjusts a mass flow rate of at least one of coal and steam supplied from a coal nozzles 18 and a steam nozzle 19 described in the first embodiment. The following operation is also done by the operator. That is, a difference in pressure between the first piping 33 and the second piping 34 is regularly or continuously measured by using the pressure meter 32. Then, when the 20 thus measured difference in pressure exceeds a predetermined reference value, steam is supplied at a predetermined mass flow rate from the steam nozzle 19 to the thermal decomposition unit 13. [0046] Fig. 5 shows an example of results obtained when a difference in pressure in the 25 thermal decomposition unit 13 was actually measured. In Fig. 5, the horizontal axis 24 indicates elapsed time (min), while the vertical axis indicates a difference in pressure between the first piping 33 and the second piping 34 (variation from an ordinary difference in pressure (kPa)). When coal tar adhered on an inner circumference surface of the thermal 5 decomposition unit 13 with the lapse of time, a difference in pressure started to rise at time TO and has arrived at a reference value of 10 (kPa) at time T1. At this time, steam was supplied at a predetermined quantity from the steam nozzle 19 to the thermal decomposition unit 13. Here, the predetermined quantity of steam is, for example, a mass flow rate which is approximately 5 to 10% of a quantity of coal fed per hour from 10 the coal nozzles 18 to the thermal decomposition unit 13. As a result, an amount of coal tar adhered inside the thermal decomposition unit 13 was decreased and the difference in pressure was lowered to an ordinary difference in pressure. In the case where the difference in pressure is not lowered to an ordinary value by 15 supplying steam at a mass flow rate corresponding to approximately 5 to 10% of a quantity of coal fed per hour, steam may be additionally supplied at a mass which is approximately 5% of a mass of coal fed per hour. In this instance, it is not necessary to keep the mass ratio of steam to carbon in a range from 1.0 to 1.5. However, it is preferable that operation is done so as to keep the mass ratio of steam to carbon in a range 20 of 1.0 to 1.5 after the difference in pressure is lowered to an ordinary difference in pressure. [0047] As described above, according to the coal gasification reaction furnace 31 of the present embodiment, since a mass flow rate of steam to be supplied is not increased more 25 than necessary, it is possible to maintain a production quantity of a combustible gas.

25 Furthermore, steam is supplied at a mass flow rate sufficient for carrying out gasification reactions of coal tar; and thereby, it is possible to effectively prevent the increasing of an adhesion amount of coal tar inside the thermal decomposition unit 13. Furthermore, the inventors have found that coal tar adheres in a concentrated 5 manner at a certain position of Dl above the coal nozzle 18 in the through hole 12 of the thermal decomposition unit 13 (for example, a position of Dl several hundred millimeters away above the coal nozzle 18). On the basis of this finding, in the above embodiment, the piping 33 and the piping 34 are respectively connected to D2 below the coal nozzle 18 at which coal tar is less likely to adhere and to the end portion 12a of the through hole 12. 10 Thereby, it is possible to prevent coal tar from adhering inside the piping 33 and the piping 34. Therefore, it is possible to accurately measure a difference in pressure, and it is also possible to more reliably prevent the through hole 12 of the thermal decomposition unit 13 from being clogged by coal tar. The first piping 33 may be connected to D2 which is a portion below the coal 15 nozzle 18 in the through hole 12 of the thermal decomposition unit 13 at which coal tar is less likely to adhere. [0048] A description has been made above for the embodiments of the present invention while referring to the drawings. However, a specific constitution shall not be restricted 20 to the embodiments, and the present invention includes modifications of constitutions and the like within a scope not departing from the features of the present invention. For example, in the first embodiment and second embodiment, the coal gasification reaction furnace may be operated as described in the following, with no moisture meter 20 installed therein. That is, a quantity of steam and a quantity of carbon 25 contained in coal and a carbonaceous material are determined in advance by calculation.

26 Then, on the basis of the calculation value, coal is supplied from the coal nozzles 18 and steam is supplied from the steam nozzle 19 into the thermal decomposition unit 13 respectively. A quantity of steam generated in the partial oxidation unit 11 can be calculated accurately to some extent by balancing oxygen, hydrogen and carbon on the 5 basis of a quantity of the carbonaceous material to be fed, compositions of the carbonaceous material, a quantity of oxygen, and a quantity of steam. The mass ratio of steam to carbon at the outlet of the thermal decomposition unit 13 can be calculated on the basis of a quantity of coal fed into the thermal decomposition unit 13, a quantity of steam fed, and a quantity of steam lost by steam reactions with carbon contained in coal. A 10 quantity of carbon in coal can be measured by a method specified in JIS M8819. As described above, in the case where no moisture meter 20 is provided, a change in the flow rate or an error in the flow rate occurs for coal, a carbonaceous material, and steam. Therefore, in order to avoid a risk that the mass ratio of steam to carbon becomes smaller than 1.0 during operation, it is necessary to increase the mass ratio of steam to 15 carbon to a value much greater than 1.0 (for example, 1.2 or more to 1.5 or less). EXAMPLES [0049] (Example 1) 20 An experiment was conducted by using the apparatus shown in Fig. 1 and dried coal containing a moisture of 3% and a carbon content of 71.8%. The coal was used not only in the thermal decomposition unit 13 but also used as a carbonaceous material supplied to the partial oxidation unit 11. A mass flow rate of coal was set to be 650 (kg/h), a flow rate of oxygen gas was 25 set to be 385 (Nm 3 /h), and a mass flow rate of steam was set to be 60 (kg/h), which were 27 supplied from all the gasification burners 17 to the partial oxidation unit 11. Furthermore, a mass flow rate of coal supplied from all the coal nozzles 18 to the thermal decomposition unit 13 was set to be 150 (kg/h), and a mass flow rate of steam fed from the steam nozzle 19 was set to be 60 (kg/h). 5 At this time, the concentration of steam contained in a synthesis gas flowing from the end portion 12a of the through hole 12 was 8.1% (percent by volume) which was measured by the moisture meter 20. And, a flow rate of a product gas on a dry basis was 1760 (Nm 3 /h). Then, a mass flow rate of carbon Qc contained in coal supplied per unit time from all the coal nozzles 18 was determined to be 104 (kg/h), a mass flow rate of 10 steam flowing from the end portion 12a of the through hole 12 was determined to be 125 (kg/h). Thus, the mass ratio of steam to carbon was 1.2. In the above operation condition (the mass ratio of steam to carbon was 1.2), after 100 hours of operation and 200 hours of operation, operation was temporarily halted to check the inside of the thermal decomposition unit 13. As a result, there was found no 15 adhesion of a carbonaceous substance derived from coal tar. [0050] (Example 2) An experiment was conducted by using the apparatus shown in Fig. 4 and dired coal containing a moisture of 3% and a carbon content of 71.8%. The coal was used not 20 only in the thermal decomposition unit 13 but also used as a carbonaceous material supplied to the partial oxidation unit 11. A mass flow rate of coal was set to be 650 (kg/h), a flow rate of oxygen gas was set to be 385 (Nm 3 /h), and a mass flow rate of steam was set to be 60 (kg/h), which were supplied from all the gasification burners 17 to the partial oxidation unit 11. 25 Furthermore, a mass flow rate of coal supplied from all the coal nozzles 18 to the thermal 28 decomposition unit 13 was set to be 150 (kg/h), and a mass flow rate of steam fed from the steam nozzle 19 was set to be 40 (kg/h). This was a condition under which the mass ratio of steam to carbon was calculated to be 1.0. However, coal having a moisture of less than 3% was fed for some time, due to a 5 change in moisture of the coal. As a result, a difference in pressure between the first piping 33 and the second piping 34 was graduallyincreased. When the difference in pressure was increased by 50% with respect to an initial difference in pressure during operation, a mass flow rate of steam fed from the steam nozzle 19 to the thermal decomposition unit 13 was increased to 60 (kg/h). Thereafter, since the difference in 10 pressure was gradually decreased, a mass flow rate of steam fed from the steam nozzle 19 to the thermal decomposition unit 13 was decreased to 50 (kg/h) at a stage where the difference in pressure was less than 10% with respect to the initial difference in pressure during operation. Thereafter, after 100 hours of operation and 200 hours of operation, operation was temporarily halted to check the inside of the thermal decomposition unit 13. 15 As a result, there was found no adhesion of a carbonaceous substance derived from coal tar. [0051] (Comparative Example 1) A mass flow rate of coal, a flow rate of oxygen gas, and a mass flow rate of steam 20 which were supplied from all the gasification burners 17 were made equal to those in Example 1. Then, a mass flow rate of coal supplied from the coal nozzles 18 was set to be 160 (kg/h), and a mass flow rate of steam supplied from the steam nozzle 19 was set to be 40 (kg/h). At this time, a concentration (concentration by volume) of steam measured by the 25 moisture meter 20 was 6.7%, and a flow rate of a product gas on a dry basis was 1775 29 (Nm 3 /h). Under these conditions, there was found an increase in an amount of coal tar adhered inside the thermal decomposition unit 13. At this time, a mass flow rate of carbon Qc contained in coal supplied per unit time from the coal nozzles 18 was determined to be 111 (kg/h) and a mass flow rate of 5 steam Qs flowing from the end portion 12a of the through hole 12 was determined to be 102 (kg/h). Thereby, a mass ratio of steam to carbon was determined to be 0.92. In the above operation condition (the mass ratio of steam to carbon was 0.92), after 100 hours of operation and 200 hours of operation, operation was temporarily halted to check the inside of the thermal decomposition unit 13. As a result, there was found 10 adhesion of a carbonaceous substance and an increase of the adhesion. [0052] (Comparative Example 2) A mass flow rate of coal, a flow rate of oxygen gas, and a mass flow rate of steam which were supplied from all the gasification burners 17 were made equal to those in 15 Example 1. Then, a mass flow rate of coal supplied from the coal nozzles 18 was set to be 125 (kg/h), and a mass flow rate of steam supplied from the steam nozzle 19 was set to be 80 (kg/h). At this time, a concentration of steam measured by the moisture meter 20 was 9.0% (concentration by volume), and a flow rate of a product gas on a dry basis was 1734 20 (Nm 3 /h). Under these conditions, there was found no adhesion inside the thermal decomposition unit 13. At this time, a mass flow rate of carbon Qc contained in coal supplied per unit time from the coal nozzles 18 was determined to be 87 (kg/h) and a mass flow rate of steam Qs flowing from the end portion 12a of the through hole 12 was determined to be 25 138 (kg/h). Thereby, a mass ratio of steam to carbon was determined to be 1.58.

30 [0053] In Examples described above, Comparative Example I and Comparative Example 2, quantities of coal and steam fed to the thermal decomposition unit 13 were adjusted in such a manner that a temperature of the thermal decomposition unit 13 was kept constant 5 (1100"C). In Examples described above, a quantity of a produced gas in terms of a flow rate on a dry basis was 1760 (Nm 3 1h) and a heating value was 8545 (kJ/Nm 3 ). In Comparative Example 1, a quantity of a produced gas was 1775 (Nm 3 h) and a heating value was 8593 (kJ/Nm 3). In Comparative Example 2, a quantity of a produced gas was 10 1734 (Nm 3 /h) and a heating value was 8495 (kJ/Nm 3 ). Examples covering the operation method of the present invention are compared with Comparative Example 1 in which adhesion was found in the thermal decomposition unit. In Examples, the quantities of a produced gas were hardly decreased and the heating values thereof were kept substantially at the same level as that of Comparative Example 1. Furthermore, it was possible to 15 conduct operation while no carbonaceous substance adhered on the apparatus. In Comparative Example 2 in which steam was fed at a greater quantity, an amount of coal fed into the thermal decomposition unit was decreased. As a result, a quantity of a produced gas was decreased. [0054] 20 A description has been made above for preferred embodiments of the present invention, and the present invention shall not be restricted to the embodiments and examples described above. The present invention may be subjected to addition, omission, replacement and other modifications of the constitution within a scope not departing from the features of the present invention. The present invention shall not be 25 restricted to the above description but will be restricted only by the scope of the attached 31 claims. INDUSTRIAL APPLICABILITY [0055] 5 According to the above-described coal gasification reaction furnace and the method for operating the coal gasification reaction furnace, it is possible to effectively prevent the increasing of an adhesion amount of coal tar inside the upper reaction vessel, with no drastic reduction in production quantity of a combustible gas. 10 Description of Symbols [0056] 4, 31: Coal gasification reaction furnace 11: Partial oxidation unit (lower reaction vessel) 12: Through hole 15 12a: End portion 13: Thermal decomposition unit (upper reaction vessel) 13a: Diameter reduced portion 17: Gasification burner 18: Coal nozzle 20 19: Steam nozzle 20: Moisture meter 32: Pressure meter 33: First piping 34: Second piping 25

Claims (6)

1. A method for operating a coal gasification reaction furnace, wherein the coal gasification reaction furnace includes: 5 a lower reaction vessel which has an accommodation space internally; and an upper reaction vessel which is installed above the lower reaction vessel and includes a through hole communicatively connected to the accommodation space of the lower reaction vessel via a diameter reduced portion and extending in a vertical direction, wherein the method for operating a coal gasification reaction furnace includes: 10 supplying a carbonaceous material, oxygen gas, and steam at a predetermined ratio into the lower reaction vessel; supplying coal and steam into the upper reaction vessel; and reacting the coal at a temperature of 950"C or higher in the upper reaction vessel by using sensible heat of a high-temperature gas from the lower reaction vessel, thereby 15 producing at least hydrogen gas and carbon monoxide gas, and wherein a mass flow rate of at least one of the coal and the steam supplied into the upper reaction vessel is adjusted in such a manner that a ratio of a mass of the steam contained in a fluid which flows per unit time from an outlet of the through hole of the upper reaction vessel to a mass of carbon contained in the coal which is supplied per unit 20 time to the upper reaction vessel becomes in a range of 1.0 or more to 1.5 or less.

2. The method for operating the coal gasification reaction furnace according to Claim 1, wherein when the mass of the steam contained in the fluid which flows per unit time from the outlet of the through hole of the upper reaction vessel is determined, a mass 25 flow rate of the fluid which flows per unit time is measured and a concentration of steam 33 contained in the fluid is also measured, and wherein a product of a measured value of the mass flow rate and a measured value of the concentration of the steam is used as the mass of the steam contained in the fluid which flows per unit time. 5

3. The method for operating the coal gasification reaction furnace according to Claim I or Claim 2, wherein a difference in pressure is measured between either of a portion below a coal nozzle of supplying the coal in the through hole of the upper reaction vessel or the 10 accommodation space of the lower reaction vessel and an upper end portion of the through hole, and wherein when the difference in pressure exceeds a predetermined value, a predetermined quantity of steam is supplied into the upper reaction vessel. 15

4. A coal gasification reaction furnace which is used in the method for operating the coal gasification reaction furnace according to any one of Claim I to Claim 3, the coal gasification reaction furnace including: a lower reaction vessel which has an accommodation space internally; and an upper reaction vessel which is installed above the lower reaction vessel and 20 includes a through hole communicatively connected to the accommodation space of the lower reaction vessel via a diameter reduced portion and extending in a vertical direction, wherein the lower reaction vessel includes a gasification burner which supplies a carbonaceous material, oxygen gas, and steam at a predetermined ratio into the lower reaction vessel to burn the carbonaceous material, and 25 wherein the upper reaction vessel includes: 34 a coal nozzle which supplies coal to the upper reaction vessel; a steam nozzle which supplies steam to the upper reaction vessel, and a moisture meter which is installed at an upper end portion of the through hole of the upper reaction vessel to measure a mass of steam flowing per unit time from the end 5 portion of the through hole.

5. The coal gasification reaction furnace according to Claim 4, which further includes a pressure meter, wherein the pressure meter includes: 10 a first piping which is connected to a portion below the coal nozzle in the through hole of the upper reaction vessel or the accommodation space of the lower reaction vessel; and a second piping which is connected to the upper end portion of the through hole of the upper reaction vessel, 15 wherein the pressure meter measures a difference in pressure between the first piping and the second piping.

6. A method for operating a coal gasification reaction furnace having a lower reaction vessel and an upper reaction vessel which are communicatively connected with each other, 20 the method for operating the coal gasification reaction furnace including: supplying a carbonaceous material, oxygen gas and steam into the lower reaction vessel; supplying coal by a coal nozzle and supplying steam by a steam nozzle into the upper reaction vessel; 25 reacting the coal inside the upper reaction vessel at a temperature of 950*C or 35 higher by using a high-temperature gas generated inside the lower reaction vessel, thereby producing a synthesis gas which contains at least hydrogen gas and carbon monoxide gas; determining a mass flow rate of steam Qs contained in the synthesis gas; determining a mass flow rate of carbon Qc supplied into the upper reaction vessel 5 on the basis of a carbon content of the coal; and adjusting at least one of a mass flow rate of the coal supplied by the coal nozzle and a mass flow rate of the steam supplied by the steam nozzle in such a manner that a ratio Qs/Qc of the mass flow rate of the steam Qs to the mass flow rate of the carbon Qc becomes in a range of 1.0 or more to 1.5 or less. 10