JP2008184531A - Method for producing solid fuel and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid fuel producing method capable of stably and efficiently producing a carbonized material having a uniform property from an organic waste such as sewage sludge having large fluctuation of properties such as treating quantity and water content at the inlet part and to provide an apparatus therefor. <P>SOLUTION: An organic waste is heated in an inlet zone 21 of a rotary kiln 1 at a temperature TS1 higher than a kiln shell temperature TS3 corresponding to the desired residual ratio of combustible materials to evaporate water in the organic waste, and heated at an intermediate kiln shell temperature TS2 in the intermediate zone 22 downstream of the inlet zone to proceed the thermal decomposition of the organic waste, and the kiln shell temperature TS3 is maintained in a temperature range corresponding to the desired residue ratio of the combustible material in the outlet zone 23 downstream of the intermediate zone to finish the thermal decomposition of the organic waste. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for producing a solid fuel that is obtained by thermally decomposing organic waste such as sewage sludge to obtain a carbide.

  Conventionally, sewage sludge has been incinerated for the purpose of volume reduction and resource recycling. However, there is a limit to the demand for construction materials obtained from incinerated ash and to secure land for landfill treatment. On the other hand, since the composition of sewage sludge is mostly organic, use of pyrolysis gas obtained by thermal decomposition as fuel gas or carbonization and use as solid fuel has been studied.

  When an organic substance is pyrolyzed and converted into fuel, it is introduced into an indirect heating type pyrolysis furnace, for example, an externally heated rotary kiln, and pyrolyzed under low oxygen without mixing the heated gas, and then pyrolyzed gas or carbide Recover. For the purpose of gasification, the heating temperature (kiln shell temperature) is set as high as possible to efficiently gasify the organic substance. On the other hand, in the case of the purpose of solid fuel conversion, it is necessary to thermally decompose at a lower temperature than in the case of gasification to leave a combustible component in the carbide.

  However, when the kiln shell temperature is lowered, the heat transfer efficiency is lowered, so that a large heat transfer area is required, the kiln becomes longer, and the treatment takes a long time, which is inefficient. Therefore, in order to efficiently thermally decompose the treated material, it is advantageous to thermally decompose at a certain high temperature. However, since the residence time of the treated material depending on the rotational speed and length of the rotary kiln is constant, the treated material is As the amount of water supplied and the amount of water vary, the final temperature of the carbide changes, and the properties of the carbide become non-uniform.

  That is, as shown in FIG. 1, when the amount of treatment and the amount of water are reduced, the thermal decomposition of the processed material starts early, and the finished temperature Ta of the carbide increases, so that the processed material is excessively carbonized and remains. The amount of combustible to do will decrease. On the contrary, when the amount of treated material and the amount of moisture increase, the start time of thermal decomposition is delayed and discharged from the kiln furnace while the temperature rise continues (Tb), so carbonization is not completed, It becomes unsuitable for use as fuel. Therefore, it has been difficult to stably and efficiently obtain a solid fuel having uniform properties from organic waste such as sewage sludge having a large variation in inlet properties such as supply amount and moisture amount.

JP-A-9-210333 JP 2000-283404 A

  The present invention has been made in view of such a situation, and its purpose is to stabilize carbides of uniform properties from organic wastes such as sewage sludge having a large variation in inlet properties such as treatment amount and moisture content. The object is to provide a solid fuel production method and apparatus that can be obtained efficiently and efficiently.

  In order to solve the above-described problems of the prior art, the present inventors conducted the following tests in order to evaluate and verify the carbonization characteristics of sewage sludge.

  First, FIG. 2 is a graph showing the weight change and temperature change in each case where a sludge sample was carbonized by using a high temperature heating furnace for experiments and holding the furnace temperature at a constant temperature of 400 ° C. and 500 ° C., respectively. It is. In any case, the weight is greatly reduced by evaporation of water after reaching from the normal temperature to 100 ° C. until the temperature starts increasing again with the start of thermal decomposition, and then further decreases with the progress of thermal decomposition. However, after the sludge sample reaches the furnace temperature, there is no change in weight, and it can be seen that carbonization does not proceed while maintaining the temperature. In addition, FIG. 3 is a graph which shows the combustible content residual rate of the carbide | carbonized_material obtained by the said experiment, and when the carbonization temperature became high temperature, it was verified that the reduction | decrease of a combustible content residual rate is remarkable.

  On the other hand, FIG. 4 shows that the treatment amount of dry sludge with a constant moisture content (25%) is −70% to +80 with respect to the rating while using an externally heated rotary kiln and keeping the kiln shell temperature at 500 ° C. It is a graph which shows the test result which fluctuated in the range to% and measured the combustible content residual rate of the carbide | carbonized_material in each case. This result shows that for large load fluctuations from -70% to + 80%, the change in the flammable residue rate of the carbide is as extremely small as ± 14%. In addition, a test was conducted to vary the moisture content within the range of ± 20% of the rating with the same amount of dry sludge treated, but in this case as well, the remaining flammable residues of carbides. It was confirmed that there was almost no change in rate.

  As a result of intensive studies by the present inventors based on the test results as described above, if a predetermined temperature zone is provided at the kiln outlet, the processed material is discharged after reaching the predetermined temperature in the zone. Since carbonization does not proceed, the inventors have obtained the knowledge that a carbide having a uniform degree of carbonization and heat can be stably obtained even if there are fluctuations in properties such as processing amount and moisture amount, and the present invention has been achieved.

  That is, the present invention provides a method for producing a solid fuel in which organic waste is thermally decomposed by an externally heated rotary kiln to obtain a carbide, and the organic waste corresponds to a desired residual combustible content in the rotary kiln inlet zone. Heating at a temperature higher than the kiln shell temperature, evaporating moisture in the organic waste and starting thermal decomposition, and at the outlet zone of the rotary kiln, setting the kiln shell temperature to a temperature range corresponding to the desired residual combustible fraction. Maintaining and terminating the thermal decomposition of the organic waste.

  Further, the present invention provides a method for producing a solid fuel in which organic waste is pyrolyzed by an externally heated rotary kiln to obtain a carbide, and the organic waste corresponds to a desired residual combustible content in the rotary kiln inlet zone. Heating at a temperature higher than the kiln shell temperature to evaporate the water in the organic waste, and in the intermediate zone downstream of the inlet zone, heating corresponding to the kiln shell temperature of the inlet zone and the desired residual combustible fraction The kiln shell temperature is heated to an intermediate temperature, the thermal decomposition of the organic waste proceeds, and the kiln shell temperature is set to a temperature range corresponding to the desired residual combustible content in the outlet zone downstream of the intermediate zone. Maintaining and terminating the thermal decomposition of the organic waste.

  Further, the present invention provides a solid fuel manufacturing apparatus for obtaining a carbide by thermally decomposing organic waste with an externally heated rotary kiln, wherein the rotary kiln has a plurality of zones with different kiln shell temperatures in the longitudinal direction, and the plurality of zones The kiln shell temperature of the exit zone located on the exit side of the rotary kiln is maintained in a temperature range corresponding to a desired combustible residual ratio, and the kiln shell temperature of the zone located upstream of the exit zone is Temperature control means for maintaining the temperature range higher than the temperature corresponding to the desired combustible content residual ratio was provided.

  In a preferred aspect of the present invention, the plurality of zones are defined by partitioning an inside of an outer cylinder through which a heating gas is circulated around the rotary kiln with a partition wall, and the rotary kiln is configured to supply one system of heating gas to the rotary kiln. The apparatus further comprises heating gas distribution means for allocating each zone at a predetermined flow rate ratio, and heating gas amount adjusting means for adjusting the total flow rate of the heating gas of the one system, wherein the temperature control means The heating gas amount adjusting means is controlled based on the measured value of the kiln shell temperature, and the kiln shell temperature in the outlet zone is maintained in a constant temperature range corresponding to a desired combustible residue rate.

  According to the method for producing a solid fuel according to the present invention, the organic waste is heated at a temperature higher than the kiln shell temperature corresponding to a desired combustible residual ratio in the inlet zone of the rotary kiln, thereby the moisture in the organic waste. Can be efficiently evaporated in a short time, and thermal decomposition can be started quickly, contributing to shortening of the overall processing time and miniaturization of the rotary kiln. Furthermore, in the rotary kiln exit zone, the thermal decomposition of organic waste is terminated in a state where the kiln shell temperature is maintained in the temperature range corresponding to the desired residual combustible fraction, so that the amount of organic waste treated and the amount of moisture Due to load fluctuations such as, the end time of thermal decomposition in the outlet zone may be around, but then carbonization does not proceed until it is discharged from the kiln, so a carbide with a uniform carbonization degree and heat quantity is stable. Is obtained. Therefore, it is possible to stably and efficiently obtain a carbide having uniform properties from an organic waste such as sewage sludge having a large variation in inlet properties such as processing amount and moisture amount.

  Furthermore, an intermediate zone is set on the downstream side of the inlet zone, in which the organic waste is heated at an intermediate kiln shell temperature between the inlet zone and the outlet zone, and thermal decomposition proceeds at an intermediate heating temperature. In this way, it is possible to suppress excessive thermal decomposition before reaching the exit zone when the amount of organic waste processed and moisture is low, and stability against load fluctuations such as organic waste processed and moisture Can be further improved. In addition, since the kiln shell temperature in the inlet zone can be set higher, it is possible to contribute to shortening the overall processing time and miniaturizing the rotary kiln.

  Further, the present invention provides a solid fuel manufacturing apparatus that obtains carbides by pyrolyzing organic waste with an external heating rotary kiln, wherein the rotary kiln has a plurality of zones with different kiln shell temperatures in the longitudinal direction, The kiln shell temperature of the exit zone located on the exit side of the rotary kiln in the zone is maintained in a temperature range corresponding to the desired residual combustible fraction, and the kiln shell temperature of the zone located upstream from the exit zone is Since temperature control means for maintaining in a temperature range higher than the temperature corresponding to the desired combustible residue residual rate is provided, uniform discharge from organic waste such as sewage sludge having a large variation in inlet properties such as treatment amount and water content In addition to being able to stably obtain the characteristic carbide, it is possible to shorten the processing time and downsize the rotary kiln.

  Further, the plurality of zones are defined by partitioning an inner portion of an outer cylinder through which the heating gas is circulated around the rotary kiln with partition walls, and the rotary kiln is configured to supply a heating gas of one system to each zone with a predetermined flow rate. Heating gas distribution means for distributing by ratio and heating gas amount adjusting means for adjusting the total flow rate of the heating gas of the one system, wherein the temperature control means is based on the measured value of the kiln shell temperature of the outlet zone In the aspect in which the heating gas amount adjusting means is controlled to maintain the kiln shell temperature in the outlet zone in a constant temperature range corresponding to the desired combustible residual rate, the heating of each zone is performed in advance. If the gas flow ratio is set, killing of all zones can be controlled by controlling the heating gas flow rate of one system to maintain the temperature of the exit zone in a certain temperature range. Can manage shell temperature, can simplify the configuration and the control system of the apparatus, it is possible to perform stable control at low cost.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
FIG. 5 shows the relationship between the heating temperature TS in each zone of the externally heated rotary kiln and the temperature T of the treated product (carbide) in the method for producing a solid fuel according to the present invention. The illustrated example shows a case where the kiln shell temperature TS has three zones (TS1, TS2, TS3) different in the longitudinal direction of the rotary kiln (processed material transfer direction).

  As already described, it has been confirmed that carbonization does not proceed until the treated product reaches a predetermined temperature corresponding to the kiln shell temperature until it is discharged. That is, the residual ratio of the combustible component remaining in the final carbide is governed by the carbonization temperature Tc in the exit zone. Therefore, in consideration of heat transfer characteristics including radiation and convection inside the kiln, the kiln shell temperature TS3 of the exit zone corresponding to the carbonization temperature Tc of the desired carbide is set, so that the kiln shell temperature TS3 becomes constant. By controlling to, a carbide having a uniform carbonization degree and heat quantity can be obtained.

  For example, from the test results of FIG. 4, if the kiln shell temperature TS3 of the exit zone is maintained in a temperature range near 450 ° C. (450 to 550 ° C.), a carbide having a residual combustible content of about 20% can be obtained. In this case, from the test result of FIG. 3, it is considered that the carbonization is terminated at the carbonization temperature Tc of 400 to 450 ° C. in the exit zone. Therefore, for example, with respect to the kiln shell temperature TS3 of the rotary kiln outlet zone of 500 ° C., the kiln shell temperature TS2 of the intermediate zone is a temperature range near 600 ° C. (550 to 650 ° C.), and the kiln shell temperature TS1 of the inlet zone is a temperature around 700 ° C. The zone is set to 650 to 750 ° C., and the processed material is heated while being transferred from the inlet zone to the intermediate zone and the outlet zone. In that case, carbonization proceeds by the following process.

  First, when the processed material is introduced into the inlet zone where the kiln shell temperature TS1 is set to the highest temperature range around 700 ° C., the processed material is heated at a temperature higher than the general heating temperature for solid fuel conversion. Evaporates efficiently. In a state where the temperature T of the processed material is maintained at 100 ° C. and the evaporation of moisture is continued, the processed material is transferred to an intermediate zone where the kiln shell temperature TS2 is set to around 600 ° C. The temperature T of the product is increased again, and the thermal decomposition of the processed product is started. The kiln shell temperature TS2 in the intermediate zone is set lower than that in the inlet zone. However, since the thermal decomposition of the processed material proceeds and the load inside the kiln is reduced, the heating amount is sufficient.

  Then, while the pyrolysis of the processed product is in progress, the carbon dioxide is transferred to the outlet zone, and while moving through the outlet zone where the kiln shell temperature TS3 is maintained in the temperature range near 500 ° C., carbonization corresponding to the heating temperature is performed. Pyrolysis is terminated at a temperature and discharged from the kiln while maintaining its carbonization degree. The carbide thus obtained has a desired combustible residue rate and has high utility value as a fuel. Further, since the water is efficiently evaporated in the inlet zone TS1 set at a high temperature, the processing time can be remarkably shortened as compared with the case where the entire kiln is maintained in the temperature range near 500 ° C., and the kiln It is possible to reduce the overall length and reduce the size.

  Further, even when the moisture content or the treatment amount of the processed material is increased and thermal decomposition starts at the end of the intermediate zone TS2, as shown by Tb in FIG. 5, a predetermined carbonization temperature Tc is reached by the end of the exit zone. The quality of the carbide is maintained as well. On the other hand, when the moisture content or the treatment amount of the processed material is reduced and the predetermined carbonization temperature Tc is reached at the point of transition from the intermediate zone TS2 to the exit zone TS3 as indicated by Ta in FIG. After that, since the carbonization does not proceed, the quality of the carbide is similarly maintained. That is, the outlet zone TS3 functions as a load absorption zone with respect to fluctuations in the water content and the processing amount of the processed material, and it is possible to stably obtain a uniform quality carbide. The above set temperatures are examples, and are set appropriately according to the desired residual ratio of combustible matter, the amount of organic waste to be treated, the amount of moisture, etc., and the temperature at which the control is performed. The range can also be set as appropriate in consideration of load fluctuations and control stability.

  Next, a solid fuel manufacturing apparatus and its operating method for carrying out the above manufacturing process will be described in detail with reference to the drawings.

  FIG. 6 shows an apparatus for producing solid fuel according to the present invention. In the figure, the apparatus for producing solid fuel includes an externally heated rotary kiln 1, which comprises an inner cylinder 11 (kiln shell), The outer cylinder 12 (muffle) which distribute | circulates heating gas to the circumference | surroundings is provided.

  The inner cylinder 11 is rotatably supported around an axis slightly inclined with respect to the horizontal, and has a plurality of fins (or spirals, not shown) arranged on the inner wall portion so as to be inclined with respect to the circumferential direction. , And can be transferred to the outlet side at a predetermined speed while heating the processed material charged from the inlet side. A screw conveyor 10 is provided at the inlet of the inner cylinder 11 for feeding a processed material, and a chute 13 is provided at the outlet of the inner cylinder 11.

  Two partition walls 14 and 15 that divide the inner space into three zones in the kiln longitudinal direction are provided around the inner wall portion of the outer cylinder 12, and an inlet zone 21, an intermediate zone 22, and an outlet zone are provided inside the outer cylinder 12. Three zones are defined. Each of these zones 21, 22, and 23 is partitioned by a partition wall (not shown) extending in the kiln longitudinal direction on one side in the circumferential direction, for example, on the side of the inner cylinder 11. Heating gas introduction portions 21a, 22a, and 23a are provided on the lower side, and heating gas delivery portions 21b, 22b, and 23b are provided on the upper side. The introduction portions of the zones 21, 22, and 23 reach the delivery portion. An independent heated gas flow path is formed.

  The introduction portions 21 a, 22 a, and 23 a of the zones 21, 22, and 23 communicate with the heated gas combustion furnace 2 through a heated gas supply pipe 20 of one system. Specifically, an introduction chamber (not shown) extending in the kiln longitudinal direction along each introduction portion is integrally provided on a side portion of the outer cylinder 12, and a heating gas supply pipe 20 is provided in the introduction chamber. It is connected.

  The delivery sections 21b, 22b, 23b of the zones 21, 22, 23 are communicated with the heated gas delivery pipe 24 via dampers 31, 32, 33, respectively. The heated gas delivery pipe 24 is connected to a heat exchanger (not shown). Then, it connects with the fan 4 (heating gas amount adjustment means) which can control ventilation volume. Specifically, a delivery chamber (not shown) extending in the kiln longitudinal direction is provided along each delivery part 21b, 22b, 23b, and a heated gas delivery pipe 24 is connected to this delivery chamber, The dampers 31, 32, and 33 are provided at the openings of the delivery portions 21b, 22b, and 23b that open into the delivery chamber.

  The openings (heating gas distribution means) of the delivery parts 21b, 22b, 23b are previously provided with a predetermined opening degree (effective flow rate) so that the heating gas is distributed to the zones 21, 22, 23 at a predetermined flow rate ratio. Road cross-sectional area). That is, the opening degree is set so that the largest amount of heated gas is distributed to the hottest inlet zone 21, and then the heated gas amount is distributed in the order of the intermediate zone 22 and the outlet zone 23. , 32, and 33, the temperature difference between the zones 21, 22, and 23 can be set freely.

  Non-contact type thermometers 51, 52 for measuring the outer surface temperature of the inner cylinder 11 in each of the zones 21, 22, 23, that is, the kiln shell temperatures TS1, TS2, TS3, are provided on the peripheral wall portion of the outer cylinder 12. 53, which have the functions of indicator (I), recorder (R), alarm (A), and thermometer 53 (temperature sensor) located in the exit zone 23 is based on the measured value The controller (C) function of outputting a control signal to the fan 4 is provided. A radiation thermometer can be used as a non-contact type thermometer.

  In the solid fuel manufacturing apparatus configured as described above, the measured value of the thermometer 53 is maintained so that the kiln shell temperature TS3 of the outlet zone 23 of the rotary kiln 1 is maintained in a temperature range corresponding to a desired combustible residual ratio. If the blast volume of the fan 4 is controlled based on the above, the amount of heated gas is distributed to the zones 21, 22, and 23 accordingly, and the temperature difference between the zones 21, 22, and 23 is maintained. At this time, even if the kiln shell temperatures TS1 and TS2 slightly fluctuate in the inlet zone 21 and the intermediate zone 22 other than the outlet zone 23, the change in the heating gas amount and the heat transfer characteristics are not linearly related. As already mentioned, it does not affect the final quality such as the residual ratio of combustible matter.

  Next, the manufacturing process of the solid fuel in the manufacturing apparatus of the said embodiment is described.

  A dryer 3 is disposed on the upstream side of the rotary kiln 1, and the sewage sludge 70 is put into the dryer 3 in a dehydrated state. The dried sludge 71 that has been stirred and dried in a high-temperature atmosphere in the dryer 3 and adjusted to a predetermined moisture content is introduced into the inner cylinder 11 of the rotary kiln 1 by the screw conveyor 10. The inlet zone 21 of the rotary kiln 1 is maintained at a kiln shell temperature TS1 higher than the heating temperature (TS3) corresponding to the desired combustible residue rate, and the moisture in the dried sludge is evaporated in the inlet zone 21.

  Next, heating is performed at an intermediate kiln shell temperature TS2 in an intermediate zone 22 on the downstream side of the inlet zone 21, and carbonization is performed by advancing thermal decomposition of the dried sludge. Subsequently, the pyrolysis is terminated in the outlet zone 23 maintained at the kiln shell temperature TS3 corresponding to the desired residual combustible fraction, and is discharged from the chute 13 as carbides 72 having a predetermined carbonization degree. A solid fuel is obtained by being cooled to room temperature by a conveyor and further humidified.

  On the other hand, the pyrolysis gas 73 generated by the pyrolysis is introduced from the chute 13 into the dry gas combustion furnace 6 and combusted together with the combustion air exchanged in the auxiliary fuel 61 and the heated gas delivery pipe 24. A part of the combustion gas 62 generated in the dry gas combustion furnace 6 is sent to the heating gas combustion furnace 2 and combusted with the auxiliary fuel 63 in the heating gas combustion furnace 2 and used for heating the rotary kiln 1 described above.

  In the above embodiment, the case where the three zones 21, 22, and 23 having different kiln shell temperatures are provided along the longitudinal direction of the rotary kiln 1, but the intermediate zone 22 is omitted and the inlet along the longitudinal direction of the rotary kiln 1 is shown. Only two zones, zone 21 and exit zone 23, may be provided. In that case, the temperature of the inlet zone 21 may be set somewhat lower, or the length of the inlet zone 21 may be shorter than the outlet zone 23 to avoid overheating when the amount of processing is small. .

  Moreover, in the said embodiment, the case where the opening degree (fixed) of sending part 21b, 22b, 23b and the opening degree adjustment (movable) of each damper 31,32,33 are used together as a heating gas distribution means is shown. However, it is also possible to make the opening degree of the delivery parts 21b, 22b, and 23b uniform and to distribute the heating gas amount by only adjusting the opening degree of the dampers 31, 32, and 33. On the contrary, it is also possible to omit the dampers 31, 32, 33 and to distribute the amount of heated gas in an inclined manner using only the openings of the delivery parts 21 b, 22 b, 23 b. In either case, the controllable temperature range is narrowed, but there is no influence on the quality of the obtained solid fuel, such as the carbonization degree and the residual combustible content.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation and change are possible based on the technical idea of this invention.

It is a figure which shows the relationship between the heating temperature at the time of the load change in a conventional carbonization furnace, and carbide | carbonized_material temperature. It is a graph which shows the weight change and temperature change in sludge sample carbonization experiment. It is a graph which shows the combustible content residual rate in sludge sample carbonization experiment. It is a graph which shows the relationship between the fluctuation | variation of the processing amount of dry sludge, and a combustible content residual rate. It is a figure which shows the relationship between the heating temperature at the time of load fluctuation | variation in the solid fuel manufacturing method of this invention embodiment, and carbide | carbonized_material temperature. It is the schematic which shows the solid fuel manufacturing apparatus of this invention embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary kiln 2 Heated gas combustion furnace 3 Dryer 4 Fan (Heating gas amount adjustment means)
5 Temperature control means 6 Dry gas combustion furnace 10 Screw conveyor 11 Inner cylinder (kiln shell)
12 outer cylinder (muffle)
13 Chute 20 Heating gas supply pipe 21 Inlet zone 21a, 22a, 23a Introduction part 21b, 22b, 23b Delivery part (heating gas distribution means)
22 Intermediate zone 23 Outlet zone 24 Heated gas delivery pipes 31, 32, 33 Damper (heating gas distribution means)
51, 52, 53 Thermometer 61, 63 Auxiliary fuel 62 Combustion gas 70 Sewage sludge 71 Dry sludge 72 Carbide 73 Pyrolysis gas T, Ta, Tb, Tc Carbonization temperature TS, TS1, TS2, TS3 Kiln shell temperature

Claims (4)

  In the method for producing a solid fuel in which organic waste is pyrolyzed by an externally heated rotary kiln to obtain a carbide, the organic waste is heated at a temperature higher than a kiln shell temperature corresponding to a desired residual combustible fraction in an inlet zone of the rotary kiln. In order to evaporate the water in the organic waste and start thermal decomposition, and maintain the kiln shell temperature in the temperature range corresponding to the desired residual combustible content in the outlet zone of the rotary kiln, A method for producing a solid fuel, characterized by terminating thermal decomposition of waste.   In the method for producing a solid fuel in which organic waste is pyrolyzed by an externally heated rotary kiln to obtain a carbide, the organic waste is heated at a temperature higher than a kiln shell temperature corresponding to a desired residual combustible fraction in an inlet zone of the rotary kiln. In the intermediate zone downstream of the inlet zone, and the intermediate temperature between the kiln shell temperature of the inlet zone and the heating temperature corresponding to the desired residual combustible content rate. The kiln shell temperature is heated, the thermal decomposition of the organic waste proceeds, the kiln shell temperature is maintained in a temperature range corresponding to the desired residual combustible fraction in the outlet zone downstream of the intermediate zone, and the organic waste A method for producing a solid fuel, characterized by terminating thermal decomposition of waste.   In an apparatus for producing a solid fuel in which organic waste is thermally decomposed by an externally heated rotary kiln to obtain a carbide, the rotary kiln has a plurality of zones with different kiln shell temperatures in a longitudinal direction, and the rotary kiln The kiln shell temperature of the exit zone located on the exit side is maintained in a temperature range corresponding to the desired combustible residue residual rate, and the kiln shell temperature of the zone located upstream from the exit zone is set to the desired combustible residue remaining. A solid fuel production apparatus comprising temperature control means for maintaining a temperature range higher than the temperature corresponding to the rate.   The plurality of zones are defined by partitioning the inside of an outer cylinder that circulates the heating gas around the rotary kiln with partition walls, and the rotary kiln is configured to supply one system of heating gas to each zone at a predetermined flow rate ratio. Heating gas distribution means for distributing and heating gas amount adjusting means for adjusting the total flow rate of the heating gas of the one system, wherein the temperature control means is based on a measured value of the kiln shell temperature of the outlet zone The said heating gas amount adjustment means is controlled, It is comprised so that the kiln shell temperature of the said exit zone may be maintained in the fixed temperature range corresponding to the desired combustible content residual rate. Solid fuel production equipment.

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