JP2005068297A - Apparatus for generating gas and method for generating gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for generating a gas and a method for generating a gas in which a combustible gas can efficiently be fed by using a catalyst capable of stably obtaining the combustible gas excellent in properties while suppressing occurrence of a tar content in a process generating the combustible gas by gasifying waste, etc. and modifying the produced gas. <P>SOLUTION: A material to be treated is gasified with a fluidized bed 12 of gasifying chamber fluidizing particulate slag C to produce the combustible gas G, in which tar content contained in the produced gas is modified and the tar content is reduced, excellent in properties. Char X produced together with gasification is introduced into a char-burning chamber 21 together with deteriorated particulate slag C2 and particulate slag is regenerated by heat after burning char and the particulate slag is returned to a gasification chamber. As a result, the activity of the particulate slag of the gasification chamber is kept and the combustible gas reduced in tar content and excellent in properties can stably be supplied. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas generation apparatus and a gas generation method, and more particularly to a gas generation apparatus and a gas generation method for gasifying an object to be processed in a fluidized bed.

  In recent years, a technique has been developed in which a gas generated in a gasifier (hereinafter referred to as “product gas”) is used as a fuel gas (hereinafter referred to as “combustible gas”) in a blast furnace or a cement firing furnace. However, in order to take out the generated gas as a combustible gas, tar (polymer hydrocarbon: precipitates at 400 ° C. or lower and causes clogging trouble) or char (containing fixed carbon, so it comes into contact with oxygen at a high temperature. And combustion), which is a factor that hinders the securing of good driving performance.

  In order to solve the above problems, a high-temperature gasifier (temperature of 1000 ° C. or higher) is provided after the low-temperature gasifier (temperature of 500 ° C. to 900 ° C.), and an oxidizing agent (oxygen, steam) is added in the high-temperature gasifier. Although a method for reforming the generated gas by using it (decomposing tar) has been developed, a part of the generated gas is combusted in order to increase the temperature of the high-temperature gasifier, so that the energy utilization efficiency is lowered.

Therefore, there is a method of performing reforming using a catalyst without using a high-temperature gasifier. For example, cracking is the decomposition of tar content into low molecular weight hydrocarbons and carbon monoxide and carbon deposited on the catalyst by thermal decomposition on the catalyst. In steam reforming or carbon dioxide reforming, the tar content is reacted with steam or carbon dioxide to reform into carbon monoxide and hydrogen gas. These reforming technologies are industrially used in petroleum refining processes, hydrogen production processes, etc., and typical metals (Al, Si, Ca, Mg), their oxides, or mixtures thereof are catalysts for cracking. Used as Specifically, zeolite (hydrous aluminosilicate), silica alumina (SiO ₂ —Al ₂ O ₃ ), activated alumina (Al ₂ O ₃ ), activated clay (SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , MgO), dolomite (CaMg (CO ₃ ) ₂ ), limestone (CaCO ₃ ), calcium oxide (CaO) and the like. For steam reforming and carbon dioxide reforming, the above-mentioned catalyst is used as a carrier, and metals (Rh, Ru, Ni, Pd, Pt, Co, Mo, Ir, Re, Fe, Na, K) or these metals are used. A catalyst (for example, Ni / Al ₂ O ₃ , Ni / CaO · Al ₂ O ₃ , Ru / MgO · Al ₂ O _3, etc.) in which at least one kind of oxide is dispersed on the support surface is used. By using these catalysts, it is possible to promote the reaction at a low temperature, but since it is necessary to raise the temperature to regenerate the catalyst, energy is eventually consumed when the catalyst is regenerated. In view of this, an apparatus has been proposed that uses the exhaust heat of cracking, steam reforming, and carbon dioxide reforming reactions for catalyst regeneration. (See Patent Document 1)
International Publication No. WO03 / 029390

  However, when used for reforming the product gas, the above-mentioned catalyst has problems in catalyst contact activity, abrasion resistance, chemical stability, price, and the like. In view of this, the present invention provides a combustible having excellent properties by minimizing the generation of tar in the process of gasifying an object to be treated such as waste with a gasifier and reforming the product gas into a combustible gas. An object of the present invention is to provide a gas generation apparatus and a gas generation method capable of efficiently supplying a combustible gas using a catalyst capable of stably obtaining a gas.

  In order to achieve the above object, the gas generating device 10 according to the invention described in claim 1, for example, as shown in FIG. 1, flows the particulate slag C inside to form a gasification chamber fluidized bed 12, A gasification chamber 11 for gasifying the workpiece A in the gasification chamber fluidized bed 12 and a char X generated by gasification in the gasification chamber 11 together with the particulate slag C2 to burn the char X The combustion chamber 21 is provided, and the particulate slag C1 heated by the combustion of the char X in the char combustion chamber 21 is returned to the gasification chamber 11.

  If comprised in this way, a to-be-processed object will be gasified by the fluidized bed in a gasification chamber, and the generated gas will be reformed by particulate slag. Therefore, combustible gas with a small tar content can be obtained. In addition, even when the surface of the product gas is deteriorated due to dirt such as carbon, the particulate slag is introduced into the char combustion chamber together with the char and heated by the combustion of the char to burn the dirt on the surface. It is played with. Since the particulate slag regenerated in the char combustion chamber is returned to the gasification chamber, the activity of the particulate slag in the gasification chamber is maintained, and the combustible gas with a small amount of tar is stably supplied.

In the gas generator according to claim 1, the particulate slag has a magnesium oxide (MgO) content of 20 wt% or more.

  If comprised in this way, in the particulate slag whose content rate of magnesium oxide (MgO) is 20 weight% or more, since a contained substance has a catalytic effect, it is effective for reforming | reforming of generated gas.

  Further, in the gas generating device according to the invention of claim 3, in the gas generating device of claim 1 or 2, the particulate slag is produced as ferronickel P or ferrochrome as shown in FIG. This is slag C obtained by granulating slag S generated in the process.

  If comprised in this way, in the slag generate | occur | produced in a ferronickel or a ferrochrome manufacturing process, since a contained substance has a catalytic effect, it is effective for a modification | reformation. Moreover, the slag generated in the ferronickel or ferrochrome manufacturing process is easy to process and can be processed into a shape suitable for gas reforming. Furthermore, the slag generated in the ferronickel or ferrochrome manufacturing process is a by-product and is therefore low cost.

  Further, the gas generating apparatus according to the invention described in claim 4 is the gas generating apparatus according to claim 3, wherein, for example, as shown in FIG. It is.

  Since the slag generated in the ferronickel or ferrochrome manufacturing process is processed into particles by the air crushing method, it becomes a granular shape close to a sphere, and a particulate slag that is hard to break and less consumed is obtained.

  Further, the gas generating device according to the invention described in claim 5 is the gas generating device according to claim 3, wherein, for example, as shown in FIG. 2, the particulate slag C is processed into a slag by the granulation method. It is.

  Since the slag generated in the ferronickel or ferrochrome production process is processed into particles by a water granulation method, a slag which is fragile and easily pulverized is obtained, and can be easily processed into an appropriate size by pulverization. Further, since the particles have an angular shape, the surface area is increased with the same volume, and particulate slag with high catalyst efficiency can be obtained.

  Further, the gas generating device according to the invention of claim 6 is the gas generating device of claim 3, wherein, for example, as shown in FIG. is there.

  When the slag generated in the ferronickel or ferrochrome production process is cooled by a slow cooling method, most of the slag becomes a vitreous slag and can be easily crushed, so that a slag processed to an appropriate size is obtained.

  The gas generator according to claim 7 is the gas generator according to any one of claims 1 to 6, wherein the particle size of the particulate slag is 16 mesh to 400 mesh. Is in range.

  When the particle size of the particulate slag is in the range of 16 mesh to 400 mesh, the particulate slag is about the same as or smaller than the particle size of silica sand generally used as a fluidized medium of the fluidized bed. It flows with the fluid medium. Further, the particulate slag is not so small as to be difficult to separate and collect, so it is suitable for collection and reuse.

  Furthermore, in the gas generating device according to the seventh aspect, the particle size of the particulate slag is 48 mesh or less.

  Since the particle size of the particulate slag is in the range of 16 mesh to 48 mesh, it is about the same size as the silica sand as the fluidized medium of the fluidized bed, and can be easily distributed evenly in the fluidized bed. It can be used as an alternative.

  Furthermore, the gas generating apparatus according to the ninth aspect of the present invention is the gas generating apparatus according to the seventh aspect, wherein the particle size of the particulate slag is 150 mesh or more.

  Since the particle size of the particulate slag is in the range of 150 mesh to 400 mesh, when the particle size is small and the specific surface area is increased, the surface area of the reacting particulate slag is increased and the efficiency as a catalyst can be improved.

  In order to achieve the above object, the gas generation method according to the invention described in claim 10 is the first flow by causing the particulate slag C to flow in the first space 11 as shown in FIG. A step of forming the bed 12, a step of introducing the workpiece A into the first fluidized bed 12, and a step of gasifying the workpiece A in the first fluidized bed 12 and generating char X And the step of introducing the char X together with the particulate slag C2 into the second space 21 different from the first space 11 to form the second fluidized bed 22, and the char in the second fluidized bed 22. A step of burning X to heat the particulate slag C2, and a step of returning the heated particulate slag C1 to the first space 11.

  With this configuration, in the first space, the object to be processed is gasified in the first fluidized bed, and further, the particulate slag is flowing in the first fluidized bed. A combustible gas with a small minute can be obtained. Furthermore, even when the surface of the product gas is deteriorated due to dirt such as carbon, the particulate slag is sent to the second space together with the char, heated by the combustion of the char, and the dirt on the surface burns. And played. Since the particulate slag regenerated in this manner is returned to the first space, the activity of the particulate slag is maintained, and the combustible gas with a small amount of tar is stably supplied.

  In the gas generator according to the present invention, the particulate slag is mixed in the fluidized medium in the fluidized bed and fluidized in the gasification chamber to form a gasification chamber fluidized bed, and the object to be processed in the gasification chamber fluidized bed. As a result, the tar content contained in the generated gas is reformed using particulate slag as a catalyst, and a combustible gas having a low tar content and excellent properties is generated. In addition, the char generated by gasification in the gasification chamber is introduced into the char combustion chamber together with the particulate slag, and the char is combusted. The slag is regenerated because it is heated by the combustion of the char and the dirt on the surface also burns and becomes clean. Since the particulate slag regenerated in the char combustion chamber is returned to the gasification chamber, the activity of the particulate slag in the gasification chamber is maintained, and a combustible gas having a low tar content and excellent properties is stably supplied. be able to.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding devices are denoted by the same reference numerals, and redundant description is omitted.

  First, with reference to the conceptual cross-sectional view of FIG. 1, the gas generator 10 which is the 1st Embodiment of this invention is demonstrated. The gas generator 10 shown in FIG. 1 is an integrated gasifier. The integrated gasification furnace 10 includes a gasification chamber 11 as a first space and a char combustion chamber 21 as a second space, which are responsible for two functions of gasification by pyrolysis and char combustion, respectively. The whole is housed in a cylindrical or rectangular furnace. The gasification chamber 11 and the char combustion chamber 21 are divided by partition walls 16, 17 and 18. The char combustion chamber 21 is further separated from the heat recovery chamber 1 by the partition wall 8. However, in the following description, the char combustion chamber 21 includes the heat recovery chamber 1. If not, note that. A gasification chamber fluidized bed 12 as a first fluidized bed containing a fluidized medium at each bottom, a char combustion chamber fluidized bed 22 as a second fluidized bed, and a heat recovery chamber fluidized bed 2 are formed. In the following description, it is assumed that the char combustion chamber fluidized bed 22 includes the heat recovery chamber fluidized bed 2. In order to cause the fluidized media in the gasification chamber fluidized bed 12 and the char combustion chamber fluidized bed 22 to flow, a diffused gas in which fluidized gases F1 and F2 are blown into the fluidized media at the bottoms of the chambers 11 and 21. A device (not shown) is provided. The air diffuser is configured to include, for example, a perforated plate laid on the bottom of the furnace, and is divided into a plurality of rooms in which the perforated plate is divided in the width direction, in order to change the superficial velocity of each part in each room. In addition, the flow velocity of the fluidized gases F1 and F2 blown out from each room of the air diffuser through the perforated plate is changed. Since the superficial velocity is relatively different in each part of the chamber, the flow state of the fluid medium and the like in each chamber is different in each part of the chamber, so that an internal swirl flow is formed. Further, since the flow state is different in each part of the chamber, the internal swirling flow circulates in each chamber in the furnace. In the figure, the thickness of the arrows indicating the fluidizing gases F1 and F2 represents the flow velocity of the fluidizing gas to be blown out, and the thick arrow portion has a larger flow velocity than the thin arrow portion.

  The gasification chamber 11 and the char combustion chamber 21 are partitioned by a partition wall 16 and a partition wall 17 (note that since this figure shows the furnace expanded in a plan view, the partition wall 16 is gasified. It is shown as if not between the chamber 11 and the char combustion chamber 21). That is, in the integrated gasification furnace 10, each chamber is not configured as a separate furnace, but is integrally configured as one furnace. Further, a sedimentation char combustion chamber 25 is provided in the vicinity of the surface of the char combustion chamber 21 in contact with the gasification chamber 11 so that the fluidized medium is lowered. That is, the char combustion chamber 21 is divided into a settling char combustion chamber 25 and a char combustion chamber main body other than the settling char combustion chamber 25. Therefore, a partition wall 18 is provided for partitioning the settled char combustion chamber 25 from the other part of the char combustion chamber (char combustion chamber main body). The partition wall 18 is lower than the upper surface of the char combustion chamber fluidized bed 22, and the fluid medium M flows from the other part of the char combustion chamber (char combustion chamber main body) to the sedimentation char combustion chamber 25 over the partition wall 18. . The sedimentation char combustion chamber 25 and the gasification chamber 11 are partitioned by a partition wall 17.

  The partition wall 17 between the gasification chamber 11 and the char combustion chamber 21 is partitioned almost entirely from the furnace ceiling 19 toward the furnace bottom (perforated plate of the diffuser), but the lower end is in contact with the furnace bottom. There is nothing, and there is an opening 26 in the vicinity of the furnace bottom. However, the upper end of the opening 26 does not reach the upper part of the upper surface of either the gasification chamber fluidized bed 12 or the char combustion chamber fluidized bed 22. That is, the gasification chamber 11 and the char combustion chamber 21 are partitioned by the partition wall 17 so that there is no gas flow in at least the upper spaces 13 and 23 of the fluidized beds 12 and 22.

  The heat recovery chamber 1 collects heat in the heat transfer tube 7 from the fluid medium M and the particulate slag C1 heated by the combustion of the char X in the char combustion chamber 21 (excluding the heat recovery chamber 1 in this paragraph). Is provided. The fluidized medium M and the particulate slag C1 flow from the char combustion chamber 21 through the partition wall 8 into the heat recovery chamber 1 and are cooled by heat exchange with the heat transfer tube 7, and then the lower opening 9 of the partition wall 8 is opened. It passes through the char combustion chamber 21 again. The heat recovery chamber 1 may not be provided. If the amount of char X generated by gasification and the amount of char X required to heat the fluid medium M and the particulate slag C2 in the char combustion chamber 21 are balanced, the heat recovery chamber 1 is unnecessary. is there. However, if the heat recovery chamber 1 is provided, the temperature of the char combustion chamber 21 is appropriately adjusted by adjusting the amount of heat recovery to process a wide variety of workpieces with different amounts of char generated. It becomes possible.

Waste A is thrown into the gasification chamber 11. The waste A thrown into the gasification chamber 11 is entrained in the fluidized medium M and the particulate slag C, and is pyrolyzed and gasified by receiving heat while being crushed. Typically, the waste A does not burn in the gasification chamber 11, but is so-called dry distillation. A temperature suitable for pyrolyzing organic wastes or the like is about 300 to 900 ° C. By the gasification, the waste A is decomposed into a product gas, which is a gas component mainly composed of hydrocarbons containing tar, and char X as a residue. The tar content in the product gas is obtained by using iron (Fe), nickel (Ni), calcium (Ca), magnesium oxide (MgO), etc. contained in the particulate slag C in the environment of the gasification chamber 11 as a catalyst. It is decomposed by the cracking reaction to be converted into methane (CH ₄ ), ethane (C ₂ H ₆ ), and the like. In addition, the temperature suitable for performing gasification and reforming in the gasification chamber 11 in which the fluidized bed 12 in which the particulate slag C is mixed is 600 to 1000 ° C. When the reformer is provided separately from the gasifier, the optimum temperature for gas reforming is 800 to 1200 ° C. Therefore, in order to gasify and reform in the gasification chamber 11, the inside of the gasification chamber 11 is preferably set to 600 to 900 ° C. By reforming, the product gas becomes a combustible gas with a small tar content and excellent properties. However, during the reforming, carbon is deposited on the particulate slag C. As a result, the activity of the particulate slag decreases as a catalyst, resulting in a deteriorated particulate slag C2.

  The char X remaining as a solid by gasification flows into the char combustion chamber 21 through the opening provided in the lower part of the partition wall 16 together with the fluid medium M and the deteriorated particulate slag C2. The char combustion chamber 21 is supplied with oxygen for burning the char. Therefore, the char X introduced from the gasification chamber 11 burns in the char combustion chamber 21, and heats the particulate slag C2 deteriorated by the heat. The deteriorated particulate slag C2 is regenerated into clean particulate slag C1 because the surface carbon burns and is removed by heating. The regenerated particulate slag C <b> 1 flows along with the fluid medium M over the upper end of the partition wall 18 into the settled char combustion chamber 25, and then flows into the gasification chamber 11 through the opening 26 at the lower part of the partition wall 17. For the regeneration of the particulate slag, the temperature is set to 800 to 1100 ° C, preferably 950 to 1100 ° C.

  A relatively large incombustible material I such as a metal piece contained in the waste A is discharged from the gasification chamber 11. Although the bottom surface of the furnace in each chamber may be horizontal, the bottom of the furnace may be inclined according to the flow of the fluid medium M or the like in the vicinity of the furnace bottom so as not to form a stagnant portion of the fluid medium M or the like. It is also possible to provide an incombustible discharge port 27 for discharging the incombustible I at the bottom of the furnace. Further, the incombustible discharge port may be provided not only at the furnace bottom of the gasification chamber 11 but also at the furnace bottom of the char combustion chamber 21. In addition, although the fluid medium M and the particulate slag C are also discharged | emitted from the furnace bottom with the incombustible material I, only the incombustible material I is discharged | emitted by the sorting apparatus (not shown), and the fluid medium M and particulate form. The slag C is returned to the gasification chamber 11.

The most preferable fluidizing gas F1 in the gasification chamber 11 is to increase the pressure of the generated gas for recycling. In this way, the gas exiting the gasification chamber is purely the gas generated from the waste A fuel, and a very high quality gas can be obtained. If this is not possible, it is preferable to use a gas (oxygen-free gas) that contains as little oxygen as possible, such as water vapor, carbon dioxide (CO ₂ ), or combustion gas obtained from the char combustion chamber 21. If the bed temperature of the fluidized medium M decreases due to the endothermic reaction during gasification, supply a combustion gas having a temperature higher than the thermal decomposition temperature as necessary, or add oxygen or oxygen in addition to the oxygen-free gas. A part of the product gas may be burned by supplying a gas, for example, air. The fluidizing gas F2 supplied to the char combustion chamber 21 supplies a gas containing oxygen necessary for char combustion, for example, air, a mixed gas of oxygen and steam. When the calorific value of the waste A fuel is low, it is preferable to increase the amount of oxygen, and oxygen is supplied as it is.

  In the integrated gasification furnace 10 described above, the gasification chamber 11 and the char combustion chamber 21 are provided through a partition wall in one furnace body, and the seal between the char combustion gas and the generated gas is completely provided. Therefore, the pressure balance control of the gasification chamber 11 and the char combustion chamber 21 is performed well, the combustion gas and the generated gas are not mixed, and the properties of the generated gas and the combustible gas G are not deteriorated. The gasification chamber fluidized bed 12 has a particulate slag C containing a catalytically active substance such as iron (Fe), nickel (Ni), calcium (Ca), magnesium oxide (MgO), Since the tar content in the product gas generated from the waste A in the gasification chamber 11 is decomposed into a hydrocarbon gas, a combustible gas having a low tar content and excellent properties is supplied.

  Further, the fluid medium M as the heat medium and the deteriorated particulate slag C2 and the char X are allowed to flow from the gasification chamber 11 side to the char combustion chamber 21 side, and further, the same amount of fluid medium M and heat regeneration. Since the particulate particulate slag C1 is configured so as to return from the char combustion chamber 21 side to the gasification chamber 11 side, the mass balance is naturally achieved, and the fluid medium M and the like are transferred from the char combustion chamber 21 side to the gasification chamber 11. In order to return to the side, there is no need for mechanical conveyance using a conveyor or the like, and there is no problem that handling of hot particles is difficult and sensible heat loss is large.

  Then, with reference to the flowchart of FIG. 2, the method to manufacture the particulate slag which can be utilized as a catalyst from the slag generated in a ferronickel manufacturing process is demonstrated. The manufacturing method from the slag generated in the ferrochrome manufacturing process is basically the same except that the raw material is not a nickel ore but a chromium ore.

  The left side of FIG. 2 shows a process for producing ferronickel P from nickel ore N. The nickel ore N contains a large amount of moisture. Therefore, the nickel ore N is put in the rotary dryer 101, and the rotary dryer 101 is rotated to flow the high-temperature dry air while stirring the nickel ore N, thereby drying the nickel ore N. The dried nickel ore N is put in a rotary kiln 102 together with coal and heated to 800 ° C. or higher. The heated nickel ore N is put into an electric furnace 103 and melted to divide it into ferronickel P and molten slag S. Ferronickel P is a raw material such as stainless steel as a product after further removing impurities as necessary.

The molten slag S, which is a by-product when producing ferronickel P, contains silica (SiO ₂ ) and magnesium oxide (MgO) as main components. Particulate slag C is formed by cooling this molten slag S and making it a fine particle size. The slag when producing ferrochrome is mainly composed of silica (SiO ₂ ), magnesium oxide (MgO) and alumina (Al ₂ O ₃ ), and is cooled and made to have a fine particle size. Particulate slag C is formed. In order to increase the nickel content, nickel (Ni) may be added to the molten slag. In order to form particulate slag from molten slag, there are three methods, a wind crushing method, a water crushing method, and a slow cooling method, which are shown in three stages in the right half of FIG.

  The air crushing method is a method in which air is blown into the molten slag S by the air crusher 111 to form a fine sphere, then a large lump is removed by the trommel 112, and the particulate slag C having a predetermined particle size is further classified by the sieve 113. It is. The trommel 112 is a rotary screen and is a device for removing a lump larger than the mesh of the screen. In order to classify into a predetermined particle size described later, a mesh having a mesh size of about 5 mm is preferable. Since the particulate slag C formed by the air crushing method is a fine crystalline sphere, it is hard to break and consumes less. The air crushing method is characterized in that spherical slag is obtained by blowing air, and the trommel 112 may not be used, or another lump removing device may be used.

  The water granulation method is a method in which water is blown to the molten slag S by the water crusher 121 and rapidly cooled, then crushed by the impeller breaker 122, and further the particulate slag C having a predetermined particle size is classified by the sieve 123. The impeller breaker 122 is a device that crushes rapidly cooled irregularly shaped slag with a rotating impeller (wing) to obtain a desired particle size. In the water granulation method, the particulate slag C having a desired particle diameter can be easily obtained by crushing with the impeller breaker 122. Moreover, since water is sprayed and rapidly cooled and then crushed by the impeller breaker 122, the particulate slag C has an angular shape, and the surface area is increased even in the same volume as the spherical shape, and high catalytic efficiency is obtained. The water granulation method is characterized in that water is blown to rapidly cool the slag, and the impeller breaker 122 may not be used, or another crushing apparatus may be used.

  In the slow cooling method, the molten slag S is deposited in the slag pits 131, and is cooled as it is to form rock. In this method, the slag formed into rock is crushed by the jaw crusher 132, the particle size is adjusted by the impeller breaker 133, and the particulate slag C having a predetermined particle size is classified by the sieve 134. The jaw crusher 132 is a device that crushes a lump of slag that has been cooled to the atmosphere by reciprocating movement of two tooth plates, and adjusts the spacing and movement of the tooth plates so as to obtain a desired particle size. The impeller breaker 133 is the same device as the impeller breaker 122 used in the water cooling method. Since it is gradually cooled by air cooling to form a rock mass, the slag becomes vitreous and can be easily crushed thereafter. Moreover, since it is crushed by the jaw crusher 132 and the impeller breaker 133 after that, the particulate slag C has an angular shape, and the surface area is increased even with the same volume compared to the spherical shape, and high catalyst efficiency is obtained. The slow cooling method is characterized in that the slag is gradually cooled by air cooling, and the crushing step is not limited to the above.

  Subsequently, the particle diameters of the sieves 113, 123, and 134 and the particulate slag C in the method for producing each particulate slag C will be described. The sieves 113, 123, and 134 are the same in any method, and are used to classify the particulate slag C having a desired particle diameter. The particulate slag C is preferably a so-called Tyler mesh having a mesh size of 16 to 400 mesh. Here, the Tyler mesh means a sieve expressed by the number of meshes in a side of 25.4 mm, 16 mesh means a sieve having an opening of 0.991 mm, and 400 mesh means an opening of 0.038 mm. Refers to the sieve. Particles having a particle size that has passed through the sieve having these openings are called 16 mesh or 400 mesh. Therefore, 16 mesh refers to a particle size of up to 0.991 mm, and 400 mesh refers to a particle size of up to 0.038 mm.

  When the particulate slag C is in the range of 16 mesh to 400 mesh, the silica sand normally used as the fluid medium M of the gasification chamber fluidized bed 12 and the char combustion chamber fluidized bed 22 is in the range of 16 mesh to 48 mesh. Therefore, the particulate slag C has a particle size comparable to or smaller than that of the fluid medium M and flows together with the fluid medium. Moreover, since it is larger than 400 mesh, it is not so small that separation / recovery becomes difficult, and it is suitable for collection and reuse.

  Further, when the particle slag C is changed from 16 mesh to 48 mesh, the particle size is about the same as that of the fluidized medium M as described above, so that it is evenly distributed in the gasification chamber fluidized bed 12 and the char combustion chamber fluidized bed 22. It is suitable because it is easy to do. Furthermore, since the particle size is about the same as that of the fluid medium M, it can be used as a substitute for the fluid medium. In addition, 48 mesh is a particle size which passes a sieve with an opening of 0.295 mm, and means a particle size of up to 0.295 mm.

  Alternatively, when the particulate slag C is changed from 150 mesh to 400 mesh, the particle size is small, the specific surface area is increased, and the surface area is increased even in the same volume, so that the catalyst efficiency is increased. In addition, 150 mesh is a particle size which passes a sieve with an opening of 0.104 mm, and means a particle size up to 0.104 mm.

  The particulate slag C is preferably classified and then subjected to a heat treatment of heating to 800 ° C. to 1100 ° C., preferably 900 ° C. to 1000 ° C. and holding for 30 minutes or more. By performing the heat treatment, it is possible to crystallize the particulate slag C which is formed by a water cooling method or a slow cooling method and is vitreous (amorphous), which is easily crushed and has no strength, and has sufficient strength. By being crystallized and having sufficient strength, even when used in a fluidized bed, it is hard to break and consumes less. This heat treatment can also be performed in the gas generator 10. That is, as a running-in operation, the particulate slag contained in the fluidized beds 12 and 22 is heat-treated by maintaining the gasification chamber 11 and the char combustion chamber 21 in the above temperature range for 30 minutes or more.

  The particulate slag C contained in the gasification chamber fluidized bed 12 and the char combustion chamber fluidized bed 22 is more preferable as the blending ratio is higher because the catalytic effect increases. In the 16 to 48 mesh particulate slag C, the blending ratio for obtaining the catalytic effect is 30 to 100% by weight, but the particulate slag C formed from the molten slag is composed of silica sand used as a fluid medium and price. Therefore, it is preferable to set it to 100% (all of which forms a fluidized bed with particulate slag C). In the 150 to 400 mesh particulate slag C, the blending ratio for obtaining the catalytic effect is 10 to 30% by weight. If the mixing ratio of the particulate slag C is too large, the fluid medium M will not flow well, so it is preferable to be about 30% by weight or less.

Until now, the particulate slag C contains a substance having a catalytic effect such as iron (Fe), nickel (Ni), calcium (Ca), magnesium oxide (MgO), and cracks tar in the gasification chamber 11. Although the case where the product gas is reformed by doing so has been described, similarly, the by-product molten slag in producing ferronickel or ferrochrome contains 5% by weight, preferably 30% by weight or more of nickel. The catalyst can be used as a catalyst for reforming the tar with steam or carbon dioxide. That is, by forming a fluidized bed for flowing particulate slag having a nickel content of 5% by weight or more, a reformed gas in which the tar content in the generated gas is converted into a hydrocarbon gas by steam reforming or carbon dioxide reforming. A gas generating device for supplying the gas is obtained. In order to increase the nickel content, nickel (Ni) may be added to the molten slag as described above. This particulate slag is also regenerated by the char combustion chamber. In order to reform the tar content in the gasification chamber 11 with steam or carbon dioxide, steam (H ₂ O) or carbon dioxide (CO ₂ ) is contained in the flowing gas F1.

  Next, the gas generating apparatus 30 according to the second embodiment of the present invention will be described with reference to the conceptual cross-sectional view of FIG. Unlike the integrated gasification furnace 10 in which the gasification chamber and the char combustion chamber are integrated, which is the first embodiment, the gas generation device 30 serves as a gasification furnace 31 as a char combustion chamber. The char combustion furnace 41 has an independent structure.

  The gas generator 30 used in the present embodiment is a two-column circulating gasifier. The two-column circulation type gasification furnace is composed of two furnaces, a gasification furnace 31 having a gasification furnace fluidized bed 32 and a char combustion furnace 41 having a char combustion furnace fluidized bed 42, and the gasification furnace 31 and the char combustion furnace 41. The fluid medium M and the particulate slag C are circulated between them, and the amount of heat necessary for gasification is supplied to the gasifier 31 by the sensible heat of the fluid medium C1 heated by the char combustion heat in the char combustion furnace 41. It is what.

  Similar to the integrated gasifier 10, there is no need to burn the combustible gas G generated in the gasifier 31, so that the calorific value of the combustible gas G can be maintained high. The two-column circulation method is more difficult to handle high temperature particles than the integrated gasification furnace 10 such as securing a sufficient amount of particle circulation between the gasification furnace 31 and the char combustion furnace 41, controlling the particle circulation amount, and stable operation. In addition, although there is an operational difficulty that the temperature control of the char combustion furnace 41 cannot be performed independently of other operations, it is used as a gas supply device taking advantage of the feature that the calorific value of the combustible gas G can be maintained high. can do. As a configuration of the gas supply device, the integrated gasification furnace 10 of the first embodiment may be replaced with a two-column circulation type gasification furnace 30. Since the basic operation and effect are the same as those in the first embodiment, a duplicate description is omitted. The integrated gasification furnace 10 and the two-column circulation type gasification furnace 30 have been described as typical examples of the gas generation apparatus, but the gas generation apparatus combusts the gasification chamber for gasifying the object to be processed and the selected char. Other types such as a combustion chamber and a catalyst regeneration chamber for heating and regenerating particulate slag deteriorated by the combustion gas may be used.

  Subsequently, with reference to the configuration diagram of FIG. 4, the gas generation apparatus 10 of the first embodiment, which is the third embodiment of the present invention, and the gas generated in the gasification furnace 10 are supplied. A cement firing system in combination with a kiln type cement firing furnace 201 as a cement firing device will be described. FIG. 4 schematically shows a basic configuration of the gasification furnace portion of the present embodiment.

  The cement firing system shown in FIG. 4 includes a gasification chamber 11 that thermally decomposes and gasifies the waste A, and a char combustion chamber 21 that combusts the char X generated in the gasification chamber 11. The combustible gas G generated in the chamber 11 and the combustion gas Z generated in the char combustion chamber 21 are separated and supplied to the cement firing furnace 201. In FIG. 4, incombustible material I, fluidized medium M and particulate slag C discharged from the furnace bottom of gasification chamber 11, partially omitted in FIG. In addition, the fluid medium M and the particulate slag C also indicate a flow returning to the gasification chamber 11.

  There are several types of cement firing furnaces, such as kiln type and fluidized bed type. Currently, the kiln type is the most used, and the raw material supplied in the rotary kiln is slowly heated and fired, and finally Reaches a high temperature of about 1400-1500 ° C. These high-temperature processes are all processes that use a large amount of fossil fuel because of the high temperature. Therefore, reducing the amount of fossil fuel used by using combustible gas or combustion gas generated from waste has a great effect on improving the economics of the process and preserving the global environment.

  The kiln type cement firing furnace 201 has a cylindrical kiln having refractory bricks attached to the inner wall. This cylindrical kiln conveys the cement raw material m in one direction while rotating slowly. The cement raw material m is heated while being conveyed and becomes a clinker. The clinker exit side of the kiln having a cylindrical structure is a kiln front part 202, and a clinker cooling device 211 for cooling the clinker n that has come out is connected to the kiln front part 202. The cooled clinker n is taken out from the clinker cooling device 211 through the path 304. The entrance side of the cement material m of the cylindrical kiln is the kiln rear part 203, and the kiln rear part 203 is provided with a calcining furnace 204 for preheating the cement material. The cement raw material m is supplied to the calciner 204 from a raw material silo (not shown) through a raw material supply path 303.

  Combustible gas G is obtained from the gasification chamber 11 and combustion gas Z is obtained from the char combustion chamber 21 as gaseous substances that can be used for cement firing from the waste A supplied to the integrated gasification furnace 10. . As described above, when the layer temperature of the char combustion chamber 21 is 950 to 1100 ° C., the combustion gas Z from the char combustion chamber 21 is a gas of 950 to 1100 ° C. mainly composed of carbon dioxide generated by complete combustion. For this reason, the utilization method is limited to heat utilization of 950 to 1100 ° C. at most.

  On the other hand, since the combustible gas G from the gasification chamber 11 has a calorific value, that is, chemical energy, it can be said that it has a potential to generate a higher temperature, although it depends on its properties. In the present embodiment, the cement firing furnace 201 is a kiln type, and the gasification chamber 11 and the kiln front part 202 of the cement kiln 201 are connected by a gas path 301. The char combustion chamber 21 and the kiln rear part 203 of the cement kiln 201 are connected by a gas path 302. The gas path 302 is divided into two forks in the middle, and one is connected to the kiln rear part 203 as it is and the other is connected to the calcining furnace 204.

  In such a configuration, the combustible gas G is input to the kiln front part 202 through the path 301, and the combustion gas Z is input to the kiln rear part 203 or the calcining furnace 204 through the path 302. Thus, the high temperature of 1400-1500 degreeC required for cement baking can be obtained by guide | inducing the combustible gas G from the gasification chamber 11 to the kiln front part 202 of the cement kiln 201, and making it burn completely here. In particular, the combustible gas G is reformed in the gasification chamber 11 and contains a small amount of tar. Therefore, the gas path 301 and the kiln front part 202 hardly cause problems such as blockage problems, which is preferable. is there.

  On the other hand, since the combustion gas Z from the char combustion chamber 21 has only sensible heat of 950 to 1100 ° C., it is difficult to use it in the kiln front part 202 that reaches 1400 to 1500 ° C. Therefore, by supplying the combustion gas Z to the calcining furnace 204 or the furnace rear part 203, drying and preheating of the cement raw material m can be mainly used.

  The apparatus that uses the gas generated by the gas generation apparatus is typically a cement baking apparatus as described above, but may be a blast furnace, a glass manufacturing apparatus, a ceramic / tile / ceramic baking apparatus.

  Hereinafter, the gas generator according to the present invention will be described in more detail with reference to Examples and Comparative Examples. FIG. 5 illustrates a system configuration of an apparatus in which gasification is performed using particulate slag. The gasification / reforming apparatus 51 is a fluidized bed type gasification apparatus, and used as a fluid medium is particulate slag CA in which molten slag generated in a ferronickel production process that also serves as a catalyst is particulated by the air crushing method. . Particulate slag CA was subjected to a heat treatment in which particles by the air crushing method of 28 mesh to 35 mesh (particle size, about 0.589 mm to 0.417 mm) were held at 900 ° C. for 1 hour, and then used. The gasification / reforming apparatus 51 performed gasification and reforming at 600 to 900 ° C., and the fluidized gas contained water vapor. Further, as a comparative example, 28 to 35 mesh silica sand was used as the granular medium. The raw material A1 of the woody biomass was introduced into the gasification / reformer 51, gasified, and the tar content was reformed by the catalytic effect of the particulate slag CA to obtain a product gas G1. Particulate slag CA ′ that has deteriorated due to gas reforming in the gasification / reformer 51 is transferred to the catalyst regeneration unit 52, and the particulate slag CA regenerated by heating is gasified / reformed again. It was configured to be transferred to the device 51.

  As the properties are summarized in FIG. 6, the particulate slag CA containing 35.5% by weight of magnesium oxide (MgO) used in this example acts as a catalyst for reforming the tar content. Moreover, in FIG. 7, the example of a component of ferronickel slag and ferrochrome slag is shown for reference. FIG. 8 shows component gas component test results in Examples and Comparative Examples. As can be seen from the component gas test results of FIG. 8, the gas was reformed by using the particulate slag CA, and the amount of carbon monoxide (CO) and hydrogen (H2) produced increased. .

  Next, referring to the system configuration diagram of FIG. 9, an embodiment in a gasification system using a small particulate slag of 200 mesh to 270 mesh (particle size, about 0.074 mm to 0.053 mm) will be described. To do. The gasification / reformer 61 is a fluidized bed type gasifier, and the fluidized medium MB and the particulate slag CB form a fluidized bed, which gasifies the raw material A1 and reforms the gas (tar decomposition). )I do. The gas GB1 generated and reformed by the gasification / reformer 61 is subjected to removal of the char XB, the ash J, and the deteriorated particulate slag CB ′ by the dust removal / reformer 62, and other devices (combustible gas GB2) ( (Not shown). At that time, the char XB, the ash J, and the deteriorated particulate slag CB ′ removed by the dust removing / reforming apparatus 62 are sent to the char combustion apparatus 65.

  The mixture of incombustible material IB, char XB, ash J, deteriorated particulate slag CB ′ and fluidized medium MB extracted from the gasification / reforming device 61 is sent to the screening device 63, sieved, and incombustible. The material IB is sorted out. The remaining char XB, ash J, deteriorated particulate slag CB ′, and fluidized medium MB are sent to the char combustion device 65, and the char XB, ash J, and deteriorated particles removed by the dust removing / reforming device 62 described above. Together with the slag CB '. The char XB is combusted by the char combustion device 65, and the particulate slag CB 'deteriorated by the combustion heat of the char XB is heated and regenerated. The heated and regenerated particulate slag CB is extracted from the furnace bottom of the char combustion device 65 together with the fluid medium MB, sent to the gasification / reformer 61, and again used as a fluid medium and a catalyst.

  Since the particulate slag CB is small, it is scattered together with the combustion gas from the char combustion device 65. Therefore, the combustion gas ZB1 from the char combustion device 65 is sent to the dust removal device 64, where the particulate slag CB and ash J are captured, and the combustion exhaust gas ZB2 from which the particulate slag CB and ash J have been removed is released to the atmosphere. . The particulate slag CB and ash J captured and removed by the dust removing device 64 are sent to the sorting device 66, the ash J is sorted and removed, and the particulate slag CB is sent to the gasification / reforming device 61. Again, it is used as a catalyst.

  In the above system configuration, nickel was added to the molten slag generated in the ferronickel production process, and the slag rapidly cooled by the water granulation method was pulverized to form particulate slag CB within the range of 200 mesh to 270 mesh. The particulate slag CB was heat-treated at 950 ° C. for 2 hours and then mixed so as to be 30% by weight with respect to the silica sand fluid medium to form a fluidized bed. Further, as a comparative example, 30% by weight of silica sand pulverized from 200 mesh to 270 mesh was mixed with silica sand as a fluidized medium to form a fluidized bed. With these gas generators, woody biomass was supplied as a raw material A1, and a gasification test was performed using a flowing gas containing water vapor at a gasification temperature of 700 ° C.

  FIG. 10 summarizes the properties of the catalyst. The particulate slag used in this example containing 30.5% by weight of magnesium oxide (MgO) and 10.5% by weight of nickel (Ni) acts as a catalyst for reforming the tar content by cracking. It is considered to act as a catalyst for steam reforming and carbon dioxide reforming. FIG. 11 shows the component test results of the product gas in this example and the reference example. As can be seen from the component gas test results of FIG. 11, the gas was reformed by using the particulate slag CB, and the amount of carbon monoxide (CO) and hydrogen (H2) produced increased. .

It is a conceptual sectional view explaining the gas generating device which is a 1st embodiment of the present invention. It is a flow figure explaining the method of manufacturing particulate slag from the slag generated in a ferronickel manufacturing process. It is a conceptual sectional view explaining a gas generating device which is a 2nd embodiment of the present invention. It is a block diagram explaining the cement baking system which is the 3rd Embodiment of this invention. It is a system configuration figure explaining a gas generating device used in the 1st example of the present invention. It is a table | surface explaining the property of the particulate slag used in the 1st Example. It is a table | surface explaining the component example of the slag which generate | occur | produces in a ferronickel manufacturing process, and the slag which generate | occur | produces in a ferrochrome manufacturing process. It is a table | surface explaining the component test result of the product gas in a 1st Example and a comparative example. It is a system block diagram explaining the gas production | generation apparatus used in the 2nd Example. It is a table | surface explaining the property of the particulate slag used in the 2nd Example. It is a table | surface explaining the component test result of the product gas in a 2nd Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas generator which is 1st Embodiment of this invention 11 Gasification chamber 12 Gasification chamber fluidized bed 21 Char combustion chamber 22 Char combustion chamber fluidized bed 30 Gas generator which is 2nd Embodiment of this invention DESCRIPTION OF SYMBOLS 31 Gasifier 32 Gasifier fluidized bed 41 Char combustion furnace 42 Char combustion furnace fluidized bed 51, 61 Gasification / reformer 52 Catalyst regeneration device 62 Dust removal / reformer 63, 66 Sorting device 64 Dust remover 65 Char combustion Chamber 111 Crusher 112 Trommel 113, 123, 133 Sieve 121 Water crusher 122, 133 Impeller breaker 131 Slag pit 132 Jaw crusher 201 Cement firing furnace A Waste C, CA, CB Particulate slag C1 Regenerated particulate slag C2, CA ', CB' Degraded particulate slag F1, F2 Fluidized gas G Combustible gas I Incombustible J Ash content M Fluid medium m Cement raw material n Clinker S Molten slag X Char

Claims (10)

A gasification chamber in which particulate slag is caused to flow inside to form a gasification chamber fluidized bed, and an object to be treated is gasified in the gasification chamber fluidized bed;
A char combustion chamber that introduces char generated along with gasification in the gasification chamber together with the particulate slag and burns the char;
Configured to return particulate slag heated by combustion of the char in the char combustion chamber to the gasification chamber;
Gas generator.   The gas generating device according to claim 1, wherein the particulate slag has a magnesium oxide (MgO) content of 20 wt% or more.   The gas generating apparatus according to claim 1 or 2, wherein the particulate slag is slag obtained by granulating slag generated in a ferronickel or ferrochrome manufacturing process.   The gas generating apparatus according to claim 3, wherein the particulate slag is slag that is processed into particles by a wind-pulverization method.   The gas generating apparatus according to claim 3, wherein the particulate slag is slag that is processed and granulated by a water granulation method.   The gas generating apparatus according to claim 3, wherein the particulate slag is slag that is processed into particles by a slow cooling method.   The gas generation device according to any one of claims 1 to 6, wherein a particle diameter of the particulate slag is in a range of 16 mesh to 400 mesh.   The gas generation device according to claim 7, wherein a particle size of the particulate slag is 48 mesh or less.   The gas generation device according to claim 7, wherein a particle size of the particulate slag is 150 mesh or more. Flowing particulate slag in a first space to form a first fluidized bed;
Introducing a workpiece into the first fluidized bed;
Gasifying the workpiece in the first fluidized bed and generating char;
Introducing the char together with the particulate slag into a second space different from the first space to form a second fluidized bed;
Burning the char in the second fluidized bed to heat the particulate slag;
Returning the heated particulate slag to the first space;
Gas generation method.

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