AU2021247762A1 - Method for producing carbide, and equipment for producing carbide - Google Patents

Abstract

Provided is a method for producing a carbide, the method involving using a rotating retort furnace including a rotating retort, a combustion chamber for heating the surface of the retort using combustion gas, and an exhaust means that exhausts the gas generated inside the retort into the combustion chamber to indirectly heat a processing material while causing the same to move within the retort, thereby generating a carbide, the method for producing a carbide including a step in which a component at or below a prescribed grain diameter is separated from the processing material before the processing material is charged into the retort.

Description

DESCRIPTION METHOD FOR PRODUCING CARBIDE, AND EQUIPMENT FOR PRODUCING CARBIDE TECHNICAL FIELD

[0001] The present invention relates to a method of producing a carbonization product and a facility of producing a carbonization product, particularly to a method of producing a carbonization product and a facility of producing a carbonization product using an external heating type rotary retort furnace which is configured to indirectly heat a target object to be processed.

BACKGROUND ART

[0002] A rotary retort furnace, also called a rotary kiln, is widely used, for instance, for reforming coal, sintering cement and ore, burning municipal waste, and carbonizing livestock manure. The rotary retort furnace is roughly divided into an internal heating type rotary retort furnace and an external heating type rotary retort furnace. The internal heating type rotary retort furnace is configured to directly heat a target object, which has been charged into the retort, by a high temperature atmosphere caused by heat generated by a burner provided in the retort and heat generated by the target object itself. On the other hand, the external heating type rotary retort furnace, which includes a heating chamber for heating a circumferential surface of the retort from the outside, is configured to indirectly heat the target object by heat supplied from combustion gas in the heating chamber.

[0003] In the above two types, the external heating type rotary retort furnace has an advantage that the target object is more easily heated evenly without a direct exposure to a high temperature atmosphere than the internal heating type rotary retort furnace. For the external heating type rotary retort furnace as described above, various techniques for effectively using energy and improving processing efficiency have been proposed.

[0004] For instance, Patent Literature 1 discloses a technique of supplying combustible gas, which has been generated from a target object in a retort, into a heating chamber via a through hole provided in a circumferential surface of the retort, in order to effectively use energy in an external heating type rotary retort furnace. Patent Literature 1 also discloses preventing the target object inside the retort from dropping into the heating chamber via the through hole by providing a pipe projecting toward an inside of the retort from a part of the retort where the through hole is provided.

CITATION LIST Patent Literature(s)

[0005] Patent Literature 1: JP 58-124192 A

SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, the technique as described in Patent Literature 1 is not sufficient to prevent the fine powdery target object from being discharged into the heating chamber through the through hole. Since the fine powdery target object floats inside the retort, even when such a pipe as described in Patent Literature 1 is provided, the fine powdery target object enters an inside of the pipe to be discharged into the heating chamber through the through hole. When an amount of the fine powdery target object to be discharged into the heating chamber increases, a load is applied on a facility for combusting unburned fine powder at a flue gas treatment process in the heating chamber, which is possibly to decrease productivity.

[0007] In view of the above, an object of the invention is to provide a method of producing a carbonized product and a facility of producing a carbonized product using an external heating type rotary retort furnace including an exhaust means configured to discharge gas generated inside a retort into a heating chamber, the method and the facility being novel, improved, and capable of preventing fine powdery target object from being discharged into the heating chamber.

MEANS FOR SOLVING THE PROBLEM(S)

[0008]

[1] A method of producing a carbonization product includes: using a rotary retort furnace that includes a rotatable retort, a heating chamber configured to heat a circumferential surface of the retort by combustion gas, and an exhaust means configured to discharge gas generated in the retort to the heating chamber; and indirectly heating a target object while moving the target object in the retort to generate a carbonization product, and the method further includes: separating a component having a predetermined particle size or smaller from the target object before being charged into the retort.

[2] The method of producing a carbonization product according to [1] further includes: processing the separated component of the target object into an agglomerated substance; and returning the agglomerated substance to the target object before being charged into the retort.

[3] The method of producing a carbonization product according to [2] further includes collecting fine powdery substances from the heating chamber, in which in the processing, the fine powdery substances and the separated component of the target object are processed into the agglomerated substance.

[4] In the method of producing a carbonization product according to [2] or [3], the separating includes: a first separation of separating a component having a first particle size or smaller from the target object; and a second separation of separating a component having a second particle size or smaller from the target object having been subjected to the first separation, and in the processing, the respective components of the target object separated in the first separation and the second separation are processed into the agglomerated substance.

[5] In the method of producing a carbonization product according to any one of

[1] to [4], the separating further includes: introducing airflow into the target object; and collecting the components of the target object scattered along with the airflow.

[6] A facility of producing a carbonization product includes: a rotary retort furnace that includes a rotatable retort, a heating chamber configured to heat a circumferential surface of the retort by combustion gas, and an exhaust means configured to discharge gas generated in the retort to the heating chamber, the facility configured to indirectly heat a target object while moving the target object in the retort, in which the facility further includes a classifying unit configured to separate a component having a predetermined particle size or smaller from the target object before being charged into the retort.

[7] The facility of producing a carbonization product according to [6] further includes: an agglomerating unit configured to process the component of the target object separated by the classifying unit into an agglomerated substance; and a conveyance unit configured to return the agglomerated substance to the target object before being charged into the retort.

[8] The facility of producing a carbonization product according to [7] further includes: a collecting unit configured to collect fine powdery substances from the heating chamber, in which the agglomerating unit is configured to process the fine powdery substances and the separated component of the target object into the agglomerated substance.

[9] In the facility of producing a carbonization product according to [7] or [8], the classifying unit includes: a first classifying unit configured to separate a component having a first particle size or smaller from the target object; and a second classifying unit configured to separate a component having a second particle size or smaller from the target object having passed through the first classifying unit, and the agglomerating unit is configured to mix the respective components of the target object separated by the first classifying unit and the second classifying unit and to process the mixed components into the agglomerated substance.

[10] In the facility of producing a carbonization product according to any one of

[6] to [9], the classifying unit includes: a dryer configured to introduce airflow into the target object to dry; and a bag filter configured to collect the component scattered along with the airflow in the dryer.

[0009] As described above, according to the above aspects of the invention, in a facility and a method of producing a carbonized product using an external heating type rotary retort furnace including an exhaust means configured to discharge gas generated inside a retort to a heating chamber, fine powder of a target object can be inhibited from being discharged from the inside of the retort into the heating chamber.

BRIEF DESCRIPTION OF DRAWING(S)

[0010] Fig. 1 schematically shows a vertical cross section of a rotary retort furnace included in a facility of producing a carbonization product according to a first exemplary embodiment of the invention. Fig. 2 shows a transverse cross section of the rotary retort furnace shown in Fig. 1. Fig. 3 shows an overall configuration of the production facility of a carbonization product according to the first exemplary embodiment of the invention. Fig. 4 is a graph showing examples of particle size distributions of coal material before being charged into a typical coal reforming facility. Fig. 5 shows an overall configuration of a facility of producing a carbonization product according to a second exemplary embodiment of the invention. Fig. 6 shows an overall configuration of a facility of producing a carbonization product according to a third exemplary embodiment of the invention.

DESCRIPTION OF EMBODIMENT(S)

[0011] A detailed description will be made below on preferable exemplary embodiments of the invention with reference to the attached drawings. It should be noted that components of the same or substantially the same function(s) and structure(s) will be denoted by the same reference numerals herein and in the drawings, omitting repetition of description thereof.

[0012] First Exemplary Embodiment Fig. 1 schematically shows a vertical cross section of a rotary retort furnace included in a facility of producing a carbonization product according to a first exemplary embodiment of the invention. Fig. 2 shows a transverse cross section of the rotary retort furnace shown in Fig. 1. In illustrated examples, a rotary retort furnace 1 includes a retort 2 and a heating chamber 3. The retort 2, which is in a form of a cylinder, rotates around a center axis 0 of the cylinder. In the heating chamber 3, an external fuel supplied from a burner 4 and combustible gas supplied from a later-described connecting pipe 8 are combusted. The retort 2 is disposed penetrating the heating chamber 3 substantially in a horizontal direction. A circumferential surface of the retort 2 is heated by combustion gas in the heating chamber 3. Moreover, the retort 2 is moderately inclined so that a side near an outlet (outlet side: right side in the figure) is lower than a side near an inlet (inlet side: left side in the figure). With this configuration, a target object to be processed (hereinafter simply referred to as "target object") is indirectly heated while being transferred through the retort 2 from the inlet to the outlet.

[0013] The inlet of the retort 2 is sealed with an inlet hood 5. The outlet of the retort 2 is sealed with an outlet hood 6. Thus, the target object can be heated within the retort 2 with the inside of the retort 2 being hermetically sealed from the external air. The target object, which has been charged from a hopper 7 provided at the inlet side of the retort 2, is heated to be dried while moving inside the retort 2 and is pyrolyzed into a carbonization product and combustible gas. The carbonization product generated by pyrolysis is collected from the outlet of the retort 2.

[0014] Meanwhile, the gas including the combustible gas generated by pyrolysis in the retort 2 is supplied to the heating chamber 3 through the connecting pipe 8. The combustible gas supplied into the heating chamber 3 through the connecting pipe 8 as described above as well as the fuel supplied by the burner 4 are mixed with the air supplied through an air supply port 9 to be burnt. An amount of the fuel supplied to the burner 4 from an outside can be reduced by thus supplying the combustible gas generated inside the retort 2 to the heating chamber 3. The waste gas inside the heating chamber 3 is discharged through a flue gas duct 10 and is subjected to a flue gas treatment process described later. The heating chamber 3 may include a bottom chute 12 for collecting the fine powdery target object discharged from the connecting pipe 8 along with the combustible gas and fine powdery substances including fly ash generated by burning the fine powdery target object. When the bottom chute 12 is not provided, fine powdery substances accumulated inside the heating chamber 3 are collected at the time of maintenance.

[0015] The connecting pipe 8 includes an intake port 8a located near a center axis o of the retort 2 in a manner to face the outlet of the retort 2, an exhaust port 8b opened in the circumferential surface of the retort 2 to be in communication with the heating chamber 3, and a pipe 8c extending between the intake port 8a and the exhaust port 8b. The pipe 8c includes a linear portion extending between the intake port 8a and the exhaust port 8b in a cross section direction of the retort 2, and a bent portion to be connected to the intake port 8a directed toward the outlet of the retort 2. In another example, the intake port 8a may be directed toward the inlet of the retort 2.

[0016] Since the intake port 8a is located near the center axis 0 as described above, the target object accumulated inside the retort 2 does not reach a height of the intake port 8a as long as an amount of the target object is proper. Even if some lumpy ones of the target object fall in a vertical direction, since the intake port 8a is directed toward the outlet of the retort 2, such ones of the target object are prevented from entering the connecting pipe 8 from the intake port 8a. However, some fine powder of the target object floating inside the retort 2 may enter the connecting pipe 8 from the intake port 8a.

[0017] Fig. 3 shows an overall configuration of a facility of producing a carbonization product according to the first exemplary embodiment of the invention. A coal reforming facility 100 shown in Fig. 3 is an example of a facility of producing a carbonization product. In the coal reforming facility 100, coal material 101 is crushed by a crusher 103 and then is aerated and dried by a dryer 105. In this process, fine powdery coal (including one generated by the crusher 103) contained in the coal material 101 is scattered along with airflow to be separated from the coal material 101. The fine powdery coal is discharged along with the airflow from the dryer 105 and collected by a bag filter 107. Meanwhile, the dried coal material 101 (dried coal) is charged into the rotary retort furnace (carbonization equipment) 1.

[0018] The dried coal is heated in the rotary retort furnace 1 to be further dried, and then carbonized. Carbonization is a process in which coal is pyrolyzed into a carbonization product (char) and combustible gas. Char 109 collected from the rotary retort furnace 1 is used as, for instance, fuel and a raw material to be processed. Meanwhile, as described above with reference to Fig.1, the combustible gas is fed into the heating chamber 3 from the retort 2 and combusted as fuel for heating the retort 2. Although not illustrated, a part of the combustible gas may be separately collected from the inside of the retort 2 and used as, for instance, fuel.

[0019] The waste gas inside the heating chamber 3 in the rotary retort furnace 1 is fed through the flue gas duct 10 shown in Fig. 1 for a flue gas treatment process 111. The flue gas treatment process 111 involves a combustion chamber 113, a boiler 115, a bag filter 117, and a flue gas processing equipment 119. In the combustion chamber 113, unburned fuel contained in waste gas (including combustible gas supplied from the inside of the retort 2) is combusted. In the combustion chamber 113, the fine powdery target object discharged from the retort 2 via the connecting pipe 8 to the heating chamber 3 is also combusted. Heat generated in the combustion chamber 113 is collected by the boiler 115. Subsequently, solid substances in waste gas including ash are collected by the bag filter 117 and then the waste gas is finally treated by the flue gas processing equipment 119.

[0020] As described above, in the rotary retort furnace 1, the accumulated ones and lumpy ones of the target object are prevented from entering the connecting pipe 8 owing to the position and the shape of the intake port 8a of the connecting pipe 8, whereas such a component is not provided for fine powder of the target object floating inside the retort 2. Accordingly, if a lot of fine powdery components are included in the target object in the retort 2, such a lot of fine powder of the target object are supposed to be discharged from the retort 2 via the connecting pipe 8 into the combustion chamber 3. In such a case, as already described above, a load is applied on, for instance, the combustion chamber 113 for combusting fine powder of the target object in the flue gas treatment process 111, which is possibly to decrease productivity.

[0021] Specifically, for instance, even if a processing capacity of the combustion chamber 113 or the like is increased corresponding to an increase in the amount of the fine powder discharged into the combustion chamber 3, productivity is decreased since the processing capacity of carbonizing the coal material 101 to form the char 109 is unchanged. Moreover, even if the processed amount of the coal material 101 is restricted to an amount such that the amount of the fine powder discharged into the combustion chamber 3 can be processed by the combustion chamber 113, productivity is also decreased since a processing capacity of the rotary retort furnace 1 becomes excessive.

[0022] Since a typical rotary retort furnace does not have the connecting pipe 8, the above-described behavior of the fine powder has not mattered. Accordingly, as shown by a dashed line in Fig. 3, fine powdery coal collected by the bag filter 107 has been directly returned to the coal material 101 (dried coal) and charged into the rotary retort furnace 1. However, the inventors have found that the rotary retort furnace 1 provided with the connecting pipe 8 causes the above-described disadvantage since the fine powdery coal contained in the coal material 101 is discharged from the retort 2 through the connecting pipe 8 into the combustion chamber 3.

[0023] Fig. 4 is a graph showing examples of particle size distributions of coal material before being charged into a typical coal reforming facility. In the illustrated examples, after the coal material 101 having an original particle size from 10 mm to 30 mm is crushed with the crusher 103 at the maximum preset particle size, the fine powdery coal is dried and scattered by the dryer 105, collected by the bag filter 107, and returned to the coal material 101. The fine powdery coal and coal material are then charged into the rotary retort furnace 1. The graph shows particle size distributions measured in four input batches, respectively. The particle size distributions show that, for instance, components having a particle size of 1 mm or less account for 20% to 35% in frequency. Although it is unclear what particle size of coal is discharged from the retort 2 through the connecting pipe 8 to the combustion chamber 3, since the amount of the fine powder that is practically combusted in the combustion chamber 113 in the flue gas treatment process 111 is increased, it is inferred that a lot of components having a relatively small particle size in the target object as described above leads to an increase in the amount of the fine powder.

[0024] Accordingly, as shown in Fig. 3, in the coal reforming facility 100 according to the exemplary embodiment, the fine powdery coal collected by the bag filter 107 is not directly returned to the coal material 101 and processed separately from the coal material 101. In this case, the dryer 105 and the bag filter 107 respectively introduce airflow into the coal material 101 (i.e. target object) and collect components of the target object scattered along with the airflow. Thus, the dryer 105 and the bag filter 107 serve as a classifier for separating a component having a particle size equal to or less than a predetermined particle size from the target object. With this configuration, the amount of the fine powder contained in the target object which are to be charged into the rotary retort furnace 1 is reducible. Consequently, the fine powder contained in the target object can be inhibited from being discharged from the retort 2 into the combustion chamber 3.

[0025] Since the fine powder contained in the target object are inhibited from being discharged from the retort 2 into the combustion chamber 3, as already described above, a load applied on, for instance, the combustion chamber 113 for combusting fine powder of the target object in the flue gas treatment process 111 is reducible, and a decrease in productivity is preventable. Moreover, the reduction in the amount of the fine powder discharged into the combustion chamber 3 inhibits air, which is supposed to be used for combusting fuel supplied from the burner 4 and combustible gas supplied via the connecting pipe 8, from being used for combusting the fine powder in the combustion chamber 3. The decrease in the efficiency of heat generation is thus preventable. Further, since the amount of the fine powder discharged into the combustion chamber 3 is reduced, the fine powder or ash left after the fine powder is combusted can be prevented from adhering on an inside of the combustion chamber 3 or a circumferential surface of the retort 2 and decreasing a heat transfer efficiency.

[0026] Second Exemplary Embodiment Fig. 5 shows an overall configuration of a facility of producing a carbonization product according to a second exemplary embodiment of the invention. A coal reforming facility 200 shown in Fig. 5 includes, in addition to the components of the coal reforming facility 100 according to the first exemplary embodiment, an agglomerating machine 201 configured to process fine powdery coal collected by the bag filter 107 into an agglomerated substance, and a conveyor 203 configured to return the agglomerated substance to the coal material 101 (dried coal) before being charged into the retort 2 of the rotary retort furnace 1. Further, the agglomerating machine 201 may process, in addition to the fine powdery coal collected by the bag filter 107, fine powdery substances collected by the bottom chute 12 of the combustion chamber 3 in the rotary retort furnace (carbonization equipment) 1 (see Figs. 1 and 2) into an agglomerated substance.

[0027] The agglomerating machine 201 is, for instance, a granulator (e.g. briquetting machine) that granulates fine powdery substances including fine powdery coal by compression. Alternatively, the agglomerating machine 201 may be a molding machine that mixes and kneads fine powdery substances including fine powdery coal with a tar binder or an organic binder and then molds the obtained substances by compression. The binder as described above does not affect a carbonization treatment of the coal material 101 because an amount of the binder mixed is as small as 10% or less and the binder is gasified when heated in the rotary retort furnace 1. Particles (pseudo particles) of the agglomerated substance processed by the agglomerating machine 201 desirably have a strength that does not disintegrate and is not re-micronized during conveyance on the conveyor 203 or the like and heating in the retort 2.

[0028] In the first exemplary embodiment described above, the fine powdery coal separated from the coal material 101 is processed separately from the coal material

101 without being returned to the coal material 101 (dried coal). Specifically, the fine powdery coal is processed by a method such as combusting the fine powdery coal separately from the coal material 101 and collecting heat. Also in this case, the productivity is improved as compared with a case where the combustion chamber 113 in the flue gas treatment process 111 is designed for having a processing capacity for combusting the fine powdery coal discharged into the combustion chamber 3. In contrast, since the agglomerating machine 201 is provided in the second exemplary embodiment, the fine powdery coal can also be agglomerated and then carbonized in the rotary retort furnace 1. This eliminates the need for a facility such as a combustion chamber or boiler for processing fine powdery coal, and also improves a yield of char 109 produced from the coal material 101. In addition, by processing the fine powdery substances collected from the combustion chamber 3 of the rotary retort furnace (carbonization equipment) 1 together with the fine powdery coal into the agglomerated substance, the yield of the char 109 produced from the coal material 101 can be further improved. It should be noted that since the fine powdery substances collected from the combustion chamber 3 include a lot of fly ash, the effect of improving the yield is greater with the fine powdery coal.

[0029] Third Exemplary Embodiment Fig. 6 shows an overall configuration of a facility of producing a carbonization product according to a third exemplary embodiment of the invention. A coal reforming facility 300 shown in Fig. 6 includes, in addition to the components of the coal reforming facility 200 according to the second exemplary embodiment, a classifier 301 into which the coal material 101 (dried coal) having passed through the dryer 105 is charged. In the exemplary embodiment, the agglomerating machine 201 mixes the fine powdery coal collected by the bag filter 107 with coal separated from the coal material 101 by the classifier 301 and having a predetermined particle size or smaller, and processes the obtained mixture into an agglomerated substance. The agglomerated substance is delivered by the conveyor 203 to be returned to the coal material 101 after passing through the classifier 301 and before being charged into the retort 2 of the rotary retort furnace 1. Also in the exemplary embodiment, in the same manner as in the above second exemplary embodiment, the agglomerating machine 201 may process, in addition to the fine powdery coal collected by the bag filter 107 and coal separated by the classifier 301 and having a predetermined particle size or smaller, fine powdery substances collected by the bottom chute 12 of the combustion chamber 3 in the rotary retort furnace (carbonization equipment) 1 (see Figs. 1 and 2) into an agglomerated substance.

[0030] The classifier 301 is a mechanical classifying unit such as a vibrating sieve and is configured to separate, from the coal material 101, coal particles having a particle size range different from that obtained by classifying using an airflow by the dryer 105 and the bag filter 107. Specifically, when the dryer 105 and the bag filter 107 separate a component (fine powdery coal) of the coal material 101 having a first particle size or smaller, the classifier 301 separates a component of the coal material 101 having a particle size equal to or smaller than a second particle size, which is larger than the first particle size. Here, the classifier 301 may be adjustable in terms of a particle size (the second particle size described above) that is a reference for separation. For instance, as for a vibrating sieve, a particle size that serves as a reference for separation can be adjusted by exchanging a plurality of sieve nets having different mesh sizes for use.

[0031] In the exemplary embodiment, not only the fine powdery coal separated by the airflow in the dryer 105 and the bag filter 107, but also coal having a larger (but smaller in the whole) particle size can be separated from the coal material 101 using the classifier 301. For instance, when not only the fine powdery coal separated by the airflow but also coal having a larger particle size are likely to float inside the retort 2 and be discharged into the combustion chamber 3 through the connecting pipe 8, such coal can also be separated from the coal material 101 by using the classifier 301 and agglomerated using the agglomerating machine 201, and then returned to the coal material 101. The classifier 301, which separates coal having alarger particle size, can naturally separate fine powdery coal as well. Since the fine powdery coal is automatically separated by airflow when drying the coal material 101 using the dryer 105 and, for instance, clogging of a sieve net in a vibrating sieve is less likely to occur due to no charge of the fine powdery coal into the classifier 301, it is advantageous to carry out classification in two stages as in the exemplary embodiment.

[0032] Alternatively, coal having a larger particle size, which are separated from the coal material 101 by the classifier 301 and mixed with the fine powdery coal by the agglomerating machine 201, may facilitate agglomerating the fine powdery coal in the agglomerating machine 201. For instance, when molding by compression is carried out using a granulator, a strength of molded pseudo particles is improved due to a suitably adjusted particle size distribution of a material. Accordingly, irrespective of possibility for the fine powdery coal to float inside the retort 2 and be discharged into the combustion chamber 3 through the connecting pipe 8, coal having a particle size required for suitably agglomerating the fine powdery coal using the agglomerating machine 201 may be separated from the coal material 101 using the classifier 301. The appropriate particle size distribution for agglomeration also depends, for instance, on a type of coal. Therefore, the particle size that is the reference for separation in the classifier 301 may be adjusted according to the type of coal. In other words, in the exemplary embodiment, the strength of the agglomerated target object can be improved by freely setting the particle size that is the reference for separation in a wider range and preparing a particle size distribution suitable for agglomerating the separated target object. Example(s)

[0033] Next, Example of the invention will be described below. In Example, coal was reformed in the coal reforming facility 200 described above in the second exemplary embodiment. A briquetting machine was used as the agglomerating machine 201. The dryer 105 and the bag filter 107 separated fine powdery coal having a particle size of approximately 1 mm or less from the coal material 101. However, in Comparative, coal was reformed in the same manner as the above by directly returning fine powdery coal separated as shown by a dashed line in Fig. 3 to the coal material 101 (dried coal). In Example and Comparative, the particle size distribution of the coal containing the fine powdery coal was the same as the example shown in Fig. 4 above. Results in Example and Comparative are shown in Table 1 below.

[0034]

Table 1

Example Comparative Ratio of Scattered Fine 5% 12% Powder Yield of Carbonization 54% 45% Product Generated Amount of 40,000 N m3/h 43,000 N m3/h Waste Gas I Table 1: Results in Example and Comparative

[0035] Among the above results, a ratio of the scattered fine powder is a mass ratio of the fine powder contained in the waste gas from the combustion chamber 3 and collected by the bag filter 117 in the flue gas treatment process 111 to the coal material 101. The fine powder includes ash of fine powdery coal that has been discharged from the retort 2 to the combustion chamber 3 via the connecting pipe 8 and combusted in the combustion chamber 3 or the combustion chamber 113 at the flue gas treatment process 111 in the rotary retort furnace 1. A yield of the carbonization product is a mass ratio of the char 109 collected from the rotary retort furnace 1 to the coal material 101. A generated amount of the waste gas is an accumulated flow volume of waste gas in the combustion chamber 3 calculated from a measurement value of a flow velocimeter set in the flue gas duct 10.

[0036] As shown in Table 1, the ratio of the scattered fine powder in Example (5%) was decreased by approximately 40% as compared with that in Comparative (12%). It is considered that this is because the fine powdery coal contained in the coal material 101 was separated, agglomerated and then carbonized, so that the amount of the fine powdery coal discharged into the combustion chamber 3 was greatly reduced. Moreover, the yield of the carbonization product in Example (54%) was increased by approximately 20% as compared with that in Comparative (45%). It is considered that this is because the fine powdery coal, which was discharged into the combustion chamber 3 in Comparative, was agglomerated and carbonized in Example, so that the ratio of the coal material 101 collected as the char 109 was increased. Further, in Example, the generated amount of the waste gas was also decreased because of not including such a waste gas caused by the fine powdery coal as compared with Comparative in which the amount of the waste gas from the fine powdery coal discharged into the combustion chamber 3 was included.

[0037] Suitable exemplary embodiments of the invention have been detailed above with reference to the attached drawings. However, the scope of the invention is not limited by the exemplary embodiments. It would be obvious for those skilled in the art to which the invention pertains that various modifications and revisions are conceivable within the technical idea described within claims, and it is understood that such modifications and revisions are naturally within the technical scope of the invention.

EXPLANATION OF CODES

[0038] 1...rotary retort furnace (carbonization equipment), 2...retort, 3...combustion chamber, 8...connecting pipe, 10...flue gas duct, 12...bottom chute, 100, 200, 300...coal reforming facility, 103...crusher, 105...dryer, 107...bag filter, 111...flue gas treatment process, 201... agglomerating machine, 203...conveyor, 301... classifier.

Claims (10)

1. CLAIM(S) 1. A method of producing a carbonization product, comprising: using a rotary retort furnace that comprises a rotatable retort, a combustion chamber configured to heat a circumferential surface of the retort by combustion gas, and an exhaust means configured to discharge gas generated in the retort to the combustion chamber; and indirectly heat a target object while moving the target object inside the retort to generate a carbonization product, the method further comprising: separating a component having a predetermined particle size or smaller from the target object before being charged into the retort.
2. 2. The method of producing a carbonization product according to claim 1, further comprising: processing the separated component of the target object into an agglomerated substance; and returning the agglomerated substance to the target object before being charged into the retort.
3. 3. The method of producing a carbonization product according to claim 2, further comprising: collecting fine powdery substances from the combustion chamber, wherein in the processing, the fine powdery substances and the separated component of the target object are processed into the agglomerated substance.
4. 4. The method of producing a carbonization product according to claim 2 or 3, wherein the separating comprises: a first separation of separating a component having a first particle size or smaller from the target object; and a second separation of separating a component having a second particle size or smaller from the target object having been subjected to the first separation, and in the processing, the respective components of the target object separated in the first separation and the second separation are processed into the agglomerated substance.
5. 5. The method of producing a carbonization product according to any one of claims 1 to 4, wherein the separating further comprises: introducing airflow into the target object; and collecting the component of the target object scattered along with the airflow.
6. 6. A facility of producing a carbonization product, comprising: a rotary retort furnace that comprises a rotatable retort, a combustion chamber configured to heat a circumferential surface of the retort by combustion gas, and an exhaust means configured to discharge gas generated in the retort to the combustion chamber, the facility configured to indirectly heat a target object while moving the target object in the retort, wherein the facility further comprises a classifying unit configured to separate a component having a predetermined particle size or smaller from the target object before being charged into the retort.
7. 7. The facility of producing a carbonization product according to claim 6, further comprising: an agglomerating unit configured to process the component of the target object separated by the classifying unit into an agglomerated substance; and a conveyance unit configured to return the agglomerated substance to the target object before being charged into the retort.
8. 8. The facility of producing a carbonization product according to claim 7, further comprising: a collecting unit configured to collect fine powdery substances from the combustion chamber, wherein the agglomerating unit is configured to process the fine powdery substances and the separated component of the target object into the agglomerated substance.
9. 9. The facility of producing a carbonization product according to claim 7 or 8, wherein the classifying unit comprises: a first classifying unit configured to separate a component having a first particle size or smaller from the target object; and a second classifying unit configured to separate a component having a second particle size or smaller from the target object having passed through the first classifying unit, and the agglomerating unit is configured to mix the respective components of the target object separated by the first classifying unit and the second classifying unit and to process the mixed components into the agglomerated substance.
10. 10. The facility of producing a carbonization product according to any one of claims 6 to 9, wherein the classifying unit comprises: a dryer configured to introduce airflow into the target object to dry; and a bag filter configured to collect the component scattered along with the airflow in the dryer.