Abstract:
The purpose of the present invention is to enable low-cost acquisition of an inert gas (low-oxygen concentration gas) promoting the release of a pyrolyzed gas from coal. The invention is provided with: a coal pyrolysis device main body ( 110 ) utilizing the rotary kiln method; exhaust means ( 118, 118   a  to  118   c,    130 ), connected to an outer cylinder ( 113 ) of the coal pyrolysis device main body ( 110 ), for exhausting an exhaust gas present inside the outer cylinder ( 113 ); gas extraction means ( 141, 141   a,    141   b,    143, 144, 144   a ) for extracting a portion of the exhaust gas exhausted by the exhaust means; and low-oxygen concentration gas supply means ( 141, 141   a,    141   b,    147, 142, 145, 145   a,    146 ) for delivering into the inner cylinder ( 112 ) the exhaust gas extracted by the gas extraction means so that the oxygen concentration of the exhaust gas is lowered.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a coal pyrolysis device. 
       BACKGROUND ART 
       [0002]    Low grade coal (low rank coal) with a high moisture content such as lignite and subbituminous coal has a low calorific content per unit weight, and therefore such coal is dried and pyrolyzed by heating and then modified in a low-oxygen atmosphere so that the surface activity is reduced, whereby the low grade coal is turned into modified coal having a high calorific content per unit weight while preventing spontaneous combustion. 
         [0003]    Here, direct heating type devices that directly heat dried coal with a heating gas (see Patent Documents 1, 2) and indirect heating type devices that indirectly heat dried coal with a heating gas are known as coal pyrolysis devices for pyrolysis of dried coal obtained by drying low grade coal as described above. The indirect heating type of device includes, for example, the rotary kiln type device that includes a fixed supported outer cylinder (jacket), and a rotatably supported inner cylinder on the inside of the outer cylinder. In such a coal pyrolysis device, heating gas is supplied within the outer cylinder (between the outer cylinder and the inner cylinder), and the dried coal is supplied to a first end side of the inner cylinder. By rotating the inner cylinder, the dried coal is heated and pyrolyzed while being agitated and moving from the first end side of the inner cylinder to a second end side. The pyrolyzed coal and the pyrolyzed gas are output from the second end side of the inner cylinder. 
       CITATION LISTS 
     Patent Literature 
       [0004]    Patent Document 1: Japanese Unexamined Patent Application Publication No. 561-64788A 
         [0005]    Patent Document 2: Japanese Unexamined Patent Application Publication No. 2012-241992A 
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0006]    The pyrolyzed gas includes not only water vapor, carbon dioxide, low molecular weight hydrocarbons (for example, methane, ethane, and the like), tar, and the like, but also a minute quantity of sulfur included in the dried coal. In order to promote the release of this minute component in the pyrolysis process, it is necessary to increase the difference in partial pressure between the pyrolyzed gas component in the atmosphere gas within the inner cylinder and the pyrolyzed gas component at the surface of the dried coal. For example, supplying low-oxygen concentration inert gas from the exterior into the inner cylinder to reduce the concentration of pyrolyzed gas in the atmosphere within the inner cylinder can be considered. 
         [0007]    Normally nitrogen gas is used as the inert gas, but in order to produce nitrogen gas by separating the nitrogen gas from air, a pressure swing adsorption (PSA) or cryogenic separation device is necessary. The quantity of nitrogen gas consumed by the coal pyrolysis device increases in accordance with the size of the coal pyrolysis device (the quantity of dried coal processed by the coal pyrolysis device), so the capacity of the PSA or cryogenic separation device increases, which increases the plant cost and the electrical power cost for producing the nitrogen gas. 
         [0008]    In light of the above, in order to solve the above problems, an object of the present invention is to provide a coal pyrolysis device capable of obtaining at low cost an inert gas (low-oxygen concentration gas) for promoting release of the pyrolyzed gas from the coal. 
       Solution to Problem 
       [0009]    The coal pyrolysis device according to a first invention for solving the above problems includes: a rotary kiln type coal pyrolysis device main body that rotatably supports an inner cylinder inside an outer cylinder, the rotary kiln type coal pyrolysis device main body being configured to supply coal into the inner cylinder from a first end side of the inner cylinder as well as supplying heating gas into the outer cylinder and rotate the inner cylinder to heat and pyrolyze the coal while moving the coal from the first end side of the inner cylinder to a second end side and agitating the coal, and to output the pyrolyzed coal and pyrolyzed gas from the second end side of the inner cylinder; exhaust means provided connected to the outer cylinder, the exhaust means being for exhausting the heating gas within the outer cylinder; gas extraction means for extracting a portion of the heating gas exhausted by the exhaust gas means; and low-oxygen concentration gas supply means for supplying the heating gas extracted by the gas extraction means into the inner cylinder so that the concentration of oxygen contained in the heating gas is reduced. 
         [0010]    The coal pyrolysis device according to a second invention for solving the above problems is the coal pyrolysis device according to the first invention as described above. In such a coal pyrolysis device, the low-oxygen concentration gas supply means include deoxygenation means for removing the oxygen contained in the heating gas, and low-oxygen concentration gas delivery means for delivering the low-oxygen concentration gas obtained from the deoxygenation means into the inner cylinder. 
         [0011]    The coal pyrolysis device according to a third invention for solving the above problems is the coal pyrolysis device according to the second invention as described above. In such a coal pyrolysis device, the deoxygenation means include fuel addition means for adding fuel to the heating gas, and a combustion catalyst provided so as to come into contact with the heating gas to which the fuel has been added. 
         [0012]    The coal pyrolysis device according to a fourth invention for solving the above problems is the coal pyrolysis device according to the third invention as described above. Such a coal pyrolysis device further includes heating means provided in the gas extraction means, the heating means being for heating the heating gas. 
         [0013]    The coal pyrolysis device according to a fifth invention for solving the above problems is the coal pyrolysis device according to the third invention as described above. Such a coal pyrolysis device further includes desulfurization means provided in the exhaust means, the desulfurization means being for removing sulfur oxide contained in the heating gas. 
         [0014]    The coal pyrolysis device according to a sixth invention for solving the above problems is the coal pyrolysis device according to the fourth invention as described above. Such a coal pyrolysis device further includes: oxygen concentration measuring means for measuring an oxygen concentration of the low-oxygen concentration gas delivered by the low-oxygen concentration gas delivery means; and fuel addition quantity control means for controlling a quantity of the fuel added by the fuel addition means on the basis of information obtained by the oxygen concentration measuring means so that the oxygen concentration of the low-oxygen concentration gas is 1.5% or less. 
         [0015]    The coal pyrolysis device according to a seventh invention for solving the above problems is the coal pyrolysis device according to the second invention as described above. In such a coal pyrolysis device, the deoxygenation means include an alternating combustion device that includes a combustion chamber to which the heating gas is delivered, a burner provided within the combustion chamber, and an alternating type heat exchanger provided within the combustion chamber in a location to which the heating gas is delivered, and fuel addition means for adding fuel to the combustion chamber. 
         [0016]    The coal pyrolysis device according to an eighth invention for solving the above problems is the coal pyrolysis device according to the seventh invention as described above. Such coal pyrolysis device further includes: oxygen concentration measuring means for measuring the concentration of oxygen contained in the heating gas delivered by the low-oxygen concentration gas delivery means; and fuel addition quantity control means for controlling a quantity of the fuel added by the fuel addition means on the basis of information obtained by the oxygen concentration measuring means so that the oxygen concentration of the low-oxygen concentration gas is 1.5% or less. 
         [0017]    The coal pyrolysis device according to a ninth invention for solving the above problems is the coal pyrolysis device according to the first invention as described above. In such a coal pyrolysis device, the low-oxygen concentration gas supply means include heating gas delivery means for delivering the heating gas extracted by the gas extraction means into the inner cylinder, and fuel addition means for adding fuel to the heating gas delivered into the inner cylinder by the heating gas delivery means. 
         [0018]    The coal pyrolysis device according to a tenth invention for solving the above problems is the coal pyrolysis device according to the ninth invention as described above. Such a coal pyrolysis device further includes: heating gas flow rate measuring means for measuring a flow rate of the heating gas delivered by the heating gas delivery means; oxygen concentration measuring means for measuring a concentration of oxygen contained in the heating gas delivered by the heating gas delivery means; and fuel addition quantity control means for controlling a quantity of the fuel added by the fuel addition means on the basis of information obtained by the heating gas flow rate measuring means and the oxygen concentration measuring means so that the oxygen concentration of the low-oxygen concentration gas is 1.5% or less. 
       Advantageous Effect of Invention 
       [0019]    According to the coal pyrolysis device of the present invention, it is possible to obtain the inert gas by reducing the concentration of oxygen contained in the heating gas that has indirectly heated the coal, using the low-oxygen concentration gas supply means. The cost of the low-oxygen concentration gas supply means itself and the operating cost thereof are lower than those of a PSA or cryogenic separation device, so the inert gas that promotes release of the pyrolyzed gas from the coal can be obtained at low cost. In the case that generating the inert gas raises the temperature of the inert gas itself, the coal within the coal pyrolysis device main body can be heated by the inert gas, which allows the size of the coal pyrolysis device main body to be reduced. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0020]      FIG. 1  is a schematic view of the configuration of a first embodiment of the coal pyrolysis device according to the present invention; 
           [0021]      FIGS. 2A and 2B  are schematic views of the configuration of a second embodiment of the coal pyrolysis device according to the present invention,  FIG. 2A  is an overall view, and  FIG. 2B  is a schematic view illustrating an alternating combustion deoxygenation device provided in the coal pyrolysis device; and 
           [0022]      FIG. 3  is a schematic view of the configuration of a third embodiment of the coal pyrolysis device according to the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    The following is a description of embodiments of the coal pyrolysis device according to the present invention based on the drawings, but the present invention is not limited to only the following embodiments described based on the drawings. 
       First Embodiment 
       [0024]    The following is a description of the first embodiment of the coal pyrolysis device according to the present invention based on  FIG. 1 . 
         [0025]    As illustrated in  FIG. 1 , a coal pyrolysis device  100  according to the present embodiment includes a coal pyrolysis device main body  110  that is coal pyrolysis means for obtaining pyrolyzed coal  2  by indirectly heating dried coal  1  with a heating gas  11 . The coal pyrolysis device main body  110  includes a hopper  111 , an inner cylinder (main body trunk)  112 , an outer cylinder (jacket)  113 , and a chute  114 . The hopper  111  is a device that receives the dried coal  1  and supplies the dried coal  1  into a first end side (proximal end side) of the inner cylinder  112 . The inner cylinder  112  is rotatably supported. The inner cylinder  112  is a device that rotates to cause the dried coal  1 , which has been supplied into the inner cylinder  112 , to move from the first end side to a second end side of the inner cylinder  112  while agitating the dried coal  1 . The outer cylinder  113  is fixed and supported so as to cover the outer peripheral surface of the inner cylinder  112  while enabling the inner cylinder  112  to rotate. The outer cylinder  113  is a device that heats the inner cylinder  112  with the heating gas  11 , which is a heating medium, that is delivered to the inside of the outer cylinder  113 . The chute  114  is a device that is connected to the second end side (distal end side) of the inner cylinder  112  so that the inner cylinder  112  can rotate and is configured to drop the pyrolyzed coal  2 , which is obtained by subjecting the dried coal  1  to indirect heating with the heating gas  11  to pyrolyze the dried coal  1 , down from the second end side of the inner cylinder  112 . In other words, the coal pyrolysis device main body  110  is a rotary kiln type device. 
         [0026]    For example, low grade coal (low rank coal) having a high water content such as lignite or subbituminous coal that has been supplied to a dryer (not illustrated on the drawings), and that is dried by hot gas (150° C. to 500° C.) that is distributed within the dryer so that the water content is substantially 0% can be used as the dried coal  1 . 
         [0027]    A first end side (proximal end side) of a pyrolyzed gas exhaust line  115  is connected to the top portion of the chute  114  of the coal pyrolysis device main body  110 . A second end side (distal end side) of the pyrolyzed gas exhaust line  115  is coupled to a combustion furnace  116 , which is heating gas generation means. Therefore, pyrolyzed gas (thermal decomposition gas)  15  released from the dried coal  1  when the dried coal  1  is indirectly heated by the heating gas  11 , and that includes water vapor, carbon dioxide, low molecular weight hydrocarbons, tar, and the like is exhausted from within the inner cylinder  112  to the combustion furnace  116  via the chute  114  and the pyrolyzed gas exhaust line  115 . 
         [0028]    The combustion furnace  116  is connected to a first end side (proximal end side) of a heating gas delivery line  117 . The combustion furnace  116  is connected to a second end side (distal end side) of an exhaust gas recirculation line  121  that is described in detail later. A second end side (distal end side) of the heating gas delivery line  117  is connected to the inside of the outer cylinder  113  of the coal pyrolysis device main body  110 . The pyrolyzed gas  15  has a combustion heat value of 5 to 15 MJ/Nm 3 , and the pyrolyzed gas  15  delivered to the combustion furnace  116  is processed by combustion together with supporting fuel (combustion improver)  16  such as natural gas, and the exhaust gas  13 . Therefore, the heating gas (combustion gas)  11  generated within the combustion furnace  116  is delivered to the inside of the outer cylinder  113  via the heating gas delivery line  117 . 
         [0029]    The outer cylinder  113  is connected to a first end side (proximal end side) of an exhaust gas exhaust line  118 . A boiler  118   a , a flow rate adjustment valve  118   b , and an exhaust fan  118   c  are provided from a first end side of the exhaust gas exhaust line  118 . The waste heat of heating gas  12  after heating the inner cylinder  112  is recovered by the boiler  118   a . By controlling the flow rate adjustment valve  118   b  and the exhaust fan  118   c , the heating gas  12  after heating the inner cylinder  112  flows from the first end side to the second end side (distal end side) of the exhaust gas exhaust line  118 . 
         [0030]    A first end side (proximal end side) of a heating gas bypass line  119  is connected between the proximal end side and the distal end side of the heating gas delivery line  117 . A second end side (distal end side) of the heating gas bypass line  119  is connected to the exhaust line  118  between the flow rate adjustment valve  118   b  and the exhaust fan  118   c . A boiler  119   a  and a flow rate adjustment valve  119   b  are provided on the heating gas bypass line  119  from a first end side thereof. The waste heat of the heating gas  11  is recovered by the boiler  119   a . By controlling the flow rate adjustment valve  119   b  and the exhaust fan  118   c , a portion of the heating gas  11  generated within the combustion furnace  116  is fed to the second end side (distal end side) of the exhaust gas exhaust line  118  from the heating gas delivery line  117  via the heating gas bypass line  119 . 
         [0031]    Therefore, by controlling the flow rate adjustment valves  118   b ,  119   b  and the exhaust fan  118   c , the exhaust gas  13  that is a mixed gas from mixing the heating gases  11 ,  12  is fed to the second end side (distal end side) of the exhaust gas exhaust line  118 . 
         [0032]    An exhaust gas processing device  130  that processes the exhaust gas  13  is provided on the second end side (distal end side) of the exhaust gas exhaust line  118 . 
         [0033]    The exhaust gas processing device  130  includes a denitrification device (denitrification means)  131 , an electrical dust collector (dust removal means)  132 , and a desulfurization device (desulfurization means)  133 . 
         [0034]    The denitrification device  131  removes nitrogen oxides (N0x) contained in the exhaust gas  13 . For example, a device that reduces nitrogen oxides such as nitric oxide to nitrogen gas by spraying an aqueous solution of ammonium chloride (not illustrated on the drawings) into the exhaust gas  13  can be used as the denitrification device  131 . 
         [0035]    The electrical dust collector  132  separates and removes fine particulate solid matter such as dust included in the exhaust gas  13 . 
         [0036]    The desulfurization device  133  removes sulfur oxides (S0x) included in the exhaust gas  13 . For example, a wet type device that converts sulfur oxides such as sulfur dioxide into calcium sulfide or the like by blowing a calcium carbonate slurry (not illustrated on the drawings) into the exhaust gas  13  can be used as the desulfurization device  133 . In this way, the SOx concentration of the exhaust gas  13  can be reduced to 50 ppm or less, so the reduction in performance due to S poisoning the combustion catalyst that is described later can be minimized, and the increase in operating cost due to replacement of the combustion catalyst can be minimized. 
         [0037]    Therefore, the NOx, dust, and SOx is removed from the exhaust gas  13  by processing in the devices  131  to  133  as described above. The exhaust gas  13  that has been processed in this way is exhausted outside the system. 
         [0038]    A first end side (proximal end side) of the exhaust gas recirculation line  121  is connected to the exhaust gas exhaust line  118  between the exhaust fan  118   c  and the denitrification device  131 . The second end side (distal end side) of the exhaust gas recirculation line  121  is connected to the combustion furnace  116 . A flow rate adjustment valve  121   a  is provided on the exhaust gas recirculation line  121 . By controlling the exhaust fan  118   c  and the flow rate adjustment valve  121   a , a portion of the exhaust gas  13  flowing through the exhaust gas exhaust line  118  is recirculated to the combustion furnace  116  via the exhaust gas recirculation line  121 . 
         [0039]    The coal pyrolysis device main body  110  as described above further includes an inert gas generation device  140  that generates inert gas  14  for promoting the release of pyrolyzed gas  15  from the dried coal  1 . 
         [0040]    The inert gas generation device  140  includes an exhaust gas extraction line  141  provided connected at a first end side (proximal end side) thereof between the second end side (distal end side) of the exhaust gas exhaust line  118  and the desulfurization device  133 . The second end side (distal end side) of the exhaust gas extraction line  141  is connected to a gas inlet of a combustion catalyst deoxygenation device (deoxygenation device)  142 . A flow rate adjustment valve  141   a , an extraction fan  141   b , and a heat exchanger (heating means)  143  are provided on the exhaust gas extraction line  141  from the first end side (proximal end side) thereof. By controlling the flow rate adjustment valve  141   a  and the extraction fan  141   b , a portion of the exhaust gas  13  that has passed through the desulfurization device  133  flows to the exhaust gas exhaust line  141  via the exhaust gas exhaust line  118 . 
         [0041]    A first end side (proximal end side) of an exhaust gas bypass line  144  is connected to the exhaust gas exhaust line  141  between the extraction fan  141   b  and the heat exchanger  143 . A second end side (distal end side) of the exhaust gas bypass line  144  is connected to the exhaust gas extraction line  141  between the heat exchanger  143  and the combustion catalyst deoxygenation device  142 . A flow rate adjustment valve  144   a  is provided on the exhaust gas bypass line  144 . By controlling the flow rate adjustment valves  141   a ,  144   a , and the extraction fan  141   b , the proportion of the exhaust gas  13  flowing to the combustion catalyst deoxygenation device  142  via the heat exchanger  143 , and the exhaust gas  13  flowing to the combustion catalyst deoxygenation device  142  via the exhaust gas bypass line  144  can be adjusted, so the temperature of the exhaust gas  13  flowing to the combustion catalyst deoxygenation device  142  is adjusted. 
         [0042]    A first end side (distal end side) of an oxygen consuming fuel supply line  145  that delivers an oxygen consuming fuel  17  for consuming oxygen in the exhaust gas  13 , for example a hydrocarbon fuel such as natural gas, is provided connected to a gas inlet of the combustion catalyst deoxygenation device  142 . A tank  146  that stores the oxygen consuming fuel  17  is provided connected to a second end side (proximal end side) of the oxygen consuming fuel delivery line  145 . A flow rate adjustment valve  145   a  is provided on the oxygen consuming fuel delivery line  145 . 
         [0043]    The combustion catalyst deoxygenation device  142  includes a pre-mixing chamber (not illustrated on the drawings) capable of generating a pre-mixed gas that is a mixture of the exhaust gas  13  and the oxygen consuming fuel  17 , and a combustion catalyst (not illustrated on the drawings) filling a location adjacent to the pre-mixing chamber and coming into contact with the pre-mixed gas, that causes the oxygen in the exhaust gas  13  to react with the oxygen consuming fuel  17  to consume the oxygen. 
         [0044]    For example, a base material formed in a honeycomb shape and the catalyst that includes a noble metal provided on the base material can be used as the combustion catalyst. For example, the base material can be made of cordierite. The noble metal may be platinum or palladium, for example. The method of providing the noble metal on the base material can be, for example, an impregnation and supporting method or a coating method. 
         [0045]    A first end side (proximal end side) of an inert gas delivery line  147  that delivers the inert gas  14  obtained by reducing the oxygen concentration of the exhaust gas  13  obtained from the combustion catalyst deoxygenation device  142  is provided connected to a gas outlet of the combustion catalyst deoxygenation device  142 . A second end side (distal end side) of the inert gas delivery line  147  is connected to a first end side (proximal end side) of the inner cylinder  112  of the coal pyrolysis device main body  110  via the heat exchanger  143 . As described in detail later, the temperature of the inert gas  14  is raised to 550° C. to 750° C., and the exhaust gas  13  can be preheated to the ignition temperature 150° C. to 350° C. of the fuel  17  by the inert gas  14  in the heat exchanger  143 . The inert gas  14  is delivered to the inner cylinder  112  of the coal pyrolysis device main body  110 . 
         [0046]    A temperature sensor  141   c  that can measure the temperature of the exhaust gas  13  flowing through the exhaust gas extraction line  141  is provided between the distal end side of the exhaust gas extraction line  141  and the heat exchanger  143 . The temperature sensor  141   c  is connected to the flow rate adjustment valve  144   a  of the exhaust gas bypass line  144  via a temperature signal cable. The degree of opening of the flow rate adjustment valve  144   a  can be adjusted on the basis of information (exhaust gas  13  temperature) obtained by the temperature sensor  141   c.    
         [0047]    An oxygen sensor (oxygen concentration measurement means)  147   a  capable of measuring the oxygen concentration of the inert gas  14  flowing through the inert gas supply line  147  is provided on the inert gas delivery line  147 . 
         [0048]    The oxygen sensor  147   a  is connected to the flow rate adjustment valve  145   a  provided on the oxygen consuming fuel delivery line  145  via an oxygen concentration signal cable. The degree of opening of the flow rate adjustment valve  145   a  can be adjusted on the basis of information (oxygen concentration of the inert gas  14 ) obtained by the oxygen sensor  147   a . In other words, the coal pyrolysis device  100  includes a control device (fuel addition quantity control means) that is not illustrated on the drawings, and the control device can control the quantity of oxygen consuming fuel  17  added by the oxygen consuming fuel delivery line  145 , the flow rate adjustment valve  145   a , and the tank  146  so that the oxygen concentration of the inert gas  14  is, for example, 1.5% or less, on the basis of the information (oxygen concentration of the inert gas  14 ) obtained by the oxygen sensor  147   a.    
         [0049]    In the present embodiment as described above, exhaust means include the exhaust gas exhaust line  118 , the boiler  118   a , the flow rate adjustment valve  118   b , the exhaust fan  118   c , the exhaust gas processing device  130 , and the like. Gas extraction means include the exhaust gas extraction line  141 , the flow rate adjustment valve  141   a , the extraction fan  141   b , the heat exchanger  143 , the exhaust gas bypass line  144 , the flow rate adjustment valve  144   a , and the like. Fuel addition means include the oxygen consuming fuel delivery line  145 , the flow rate adjustment valve  145   a , the tank  146 , and the like. Deoxygenation means include the combustion catalyst deoxygenation device  142 , the fuel addition means, and the like. Low-oxygen concentration gas delivery means include the exhaust gas extraction line  141 , the flow rate adjustment valve  141   a , the extraction fan  141   b , the inert gas delivery line  147 , and the like. Low-oxygen concentration gas supply means include the low-oxygen concentration gas delivery means, the deoxygenation means, and the like. The coal pyrolysis device  100  includes the coal pyrolysis device main body  110 , the exhaust means, the gas extraction means, the low-oxygen concentration gas supply means, the fuel addition control means, and the like. 
         [0050]    The following is a description of a coal pyrolysis processing method for pyrolysis of dried coal  1  using the coal pyrolysis device  100  according to the present embodiment configured in this way. 
         [0051]    When dried coal  1  is fed into the hopper  111  of the coal pyrolysis device main body  110 , the dried coal  1  within the hopper  111  is supplied from the first end side (proximal end side) to the interior of the inner cylinder  112 . The dried coal  1  within the inner cylinder  112  is moved from the first end side (proximal end side) to the second end side (distal end side) of the inner cylinder  112  by the rotation of the inner cylinder  112 . The inner cylinder  112  is heated by the heating gas  11  delivered within the outer cylinder  113 , so when the dried coal  1  is moving from the first end side to the second end side of the inner cylinder  112 , the dried coal  1  is indirectly heated (300° C. to 500° C.) by the heating gas  11 . In this way, the pyrolyzed gas (thermal decomposition gas)  15  that includes water vapor, carbon dioxide, low molecular weight hydrocarbons, tar, and the like, together with minute quantities of sulfur is released from the dried coal  1 , and the separated pyrolyzed coal  2  is obtained. 
         [0052]    The pyrolyzed coal  2  drops down from the second end side of the inner cylinder  112  via the chute  114 . The pyrolyzed coal  2  that has dropped down from the chute  114  is supplied to a cooler that is not illustrated on the drawings, for example, and is cooled (150° C. to 200° C.). Active sites (radicals) produced by pyrolysis are inactivated by an inactivation processing device (not illustrated on the drawings), then the product is mixed with binder and water by a mixing device (not illustrated on the drawings), and coal briquettes are formed by compression and molding in a molding device (not illustrated on the drawings). 
         [0053]    The pyrolyzed gas  15  separated and removed from the dried coal  1  is delivered to the combustion furnace  116  via the pyrolyzed gas exhaust line  115 . 
         [0054]    Within the combustion furnace  116 , the heating gas (combustion gas)  11  is generated by combustion processing of the pyrolyzed gas  15  together with the supporting fuel  16  and the exhaust gas  13 . In the combustion furnace  116 , the ratio of the supporting fuel  16  and the air flow rate is controlled by controlling the combustion air ratio, and normally the combustion excess air ratio is set to 1.0 or higher in order to prevent generation of unburned components such as soot, and prevent lowering of the combustion efficiency. Therefore, the oxygen concentration in the heating gas (combustion gas)  11  is in the order of 2 to 5%. By controlling the flow rate adjustment valve  118   b  and the exhaust fan  118   c , a portion of the heating gas  11  is delivered to within the outer cylinder  113  through the heating gas delivery line  117 , and after the inner cylinder  112  is heated, the heating gas  12  flows to the distal end side of the exhaust gas exhaust line  118  from within the outer cylinder  113 . The remainder of the heating gas  11  is delivered to the exhaust gas exhaust line  118  via the heating gas bypass line  119 . The heating gas  12 , from which the waste heat has been recovered by the boiler  118   a , has a specific temperature (for example, 350° C.). The heating gas  11  flowing through the heating gas bypass line  119 , from which the waste heat has been recovered by the boiler  119   a , has a specific temperature (for example, 350° C.). Exhaust gas (mixed gas)  13  that is a mixture of the heating gas  12  from which the waste heat has been recovered in the boiler  118   a  and the heating gas  11  from which the waste heat has been recovered in the boiler  119   a  is delivered to the second end side (distal end side) of the exhaust gas exhaust line  118  by the exhaust fan  118   c , and is processed in the exhaust gas processing device  130 . 
         [0055]    A portion of the exhaust gas  13  that flows through the exhaust gas exhaust line  118  is recirculated to the combustion furnace  116  via the exhaust gas recirculation line  121 , by controlling the flow rate adjustment valve  121   a.    
         [0056]    The exhaust gas  13  that is not circulated to the exhaust gas recirculation line  121  but flows to the distal end side of the exhaust gas exhaust line  118  has NOx removed by the denitrification device  131 , solid matter removed by the electrical dust collector  132 , and SOx removed by the desulfurization device  133 , and is released outside the system. 
         [0057]    When producing the pyrolyzed coal  2  from the dried coal  1  in this way, the quantity of inert gas that promotes release of the pyrolyzed gas  15  from the dried coal  1  increases in accordance with the quantity of pyrolyzed coal  2  produced, and the capacity of the PSA or cryogenic separation device that produces the inert gas is increased accordingly, so the plant cost and the electrical power cost are increased. 
         [0058]    In the coal pyrolysis device  100  according to this embodiment that addresses this problem, in order to reuse the exhaust gas  13  exhausted outside the system through the exhaust gas exhaust line  118 , the following operation is additionally carried out. 
         [0059]    By controlling the flow rate adjustment valve  141   a  and the extraction fan  141   b  provided on the exhaust gas extraction line  141 , a portion of the exhaust gas  13  that has passed through the desulfurization device  133  is not exhausted outside the system via the exhaust gas exhaust line  118  but flows to the exhaust gas extraction line  141 . By controlling the flow rate adjustment valve  144   a  on the basis of the information (temperature of the exhaust gas  13 ) obtained from the temperature sensor  141   c , the proportion of the exhaust gas  13  flowing to the combustion catalyst deoxygenation device  142  via the heat exchanger  143 , and the exhaust gas  13  flowing to the combustion catalyst deoxygenation device  142  via the exhaust gas bypass line  144  is adjusted, so the exhaust gas  13 , which has been preheated to the ignition temperature 150° C. to 350° C. of the oxygen consuming fuel  17  in the heat exchanger  143 , flows to the combustion catalyst deoxygenation device  142 . By providing the exhaust gas bypass line  144  and the flow rate adjustment valve  144   a , the preheating temperature of the exhaust gas  13  can be adjusted accordingly, even if the ignition temperature of the oxygen consuming fuel  17  rises due to degradation in the performance of the combustion catalyst of the combustion catalyst deoxygenation device  142  with time. 
         [0060]    By controlling the flow rate adjustment valve  145   a  on the basis of the information (oxygen concentration of the inert gas  14 ) obtained from the oxygen sensor  147   a , a specific quantity of oxygen consuming fuel  17  is delivered to the combustion catalyst deoxygenation device  142 . In other words, the oxygen concentration of the inert gas  14  can be reduced to a specific value or lower by feedback control. Preferably, the specific value is 1.5% or less. In this way, the pyrolysis loss due to the oxygen in the inert gas  14  reacting with the dried coal  1  can be minimized. 
         [0061]    In the combustion catalyst deoxygenation device  142 , the mixed gas obtained by pre-mixing the exhaust gas  13  and the oxygen consuming fuel  17  comes into contact with the combustion catalyst, which causes the oxygen consuming fuel  17  to burn and the oxygen in the exhaust gas  13  to be consumed, to reduce the oxygen concentration of the exhaust gas  13 . At this time, the temperature of the inert gas  14  formed by reducing the oxygen concentration of the exhaust gas  13  is raised to 550° C. to 750° C. by the heat of reaction. The inert gas  14  is supplied to the inner cylinder  112  of the coal pyrolysis device main body  110  via the inert gas delivery line  147 . The quantity of inert gas  14  to be delivered is adjusted to 0.1 N·m 3  to 0.3 N·m 3  per 1 kg of dried coal  1  supplied to the inner cylinder  112 . In this way, the partial pressure of the pyrolyzed gas  15  at the surface of the dried coal  1  is reduced, which promotes the release of the pyrolyzed gas  15  from the dried coal  1 . 
         [0062]    Therefore, according to the coal pyrolysis device  100  of the present embodiment, it is possible to process the exhaust gas  13  produced by the coal pyrolysis device main body  110  in the combustion catalyst deoxygenation device  142  to obtain the inert gas  14 . The cost of the combustion catalyst deoxygenation device  142  itself and the operating cost thereof are lower than those of a PSA or cryogenic separation device, so the inert gas  14  that promotes release of the pyrolyzed gas  15  from the dried coal  1  can be obtained at low cost. 
         [0063]    Also, the temperature of the inert gas  14  obtained from the combustion catalyst deoxygenation device  142  is about 550° C. to 750° C., so the dried coal  1  within the inner cylinder  112  is directly heated by the inert gas  14  in addition to being indirectly heated by the heating gas  11 . In other words, in addition to the heating gas  11 , the inert gas  14  can be used as the heat source (pyrolysis heat source) when pyrolyzing the dried coal  1 . In this way, the quantity of heat supplied from outside the coal pyrolysis device main body  110  as the pyrolysis heat source, in other words the flow rate of the heating gas  11 , can be reduced, and the heat load of the coal pyrolysis device main body  110  can be reduced. As a result, the total length of the outer cylinder  113  (coal pyrolysis device main body  110 ) can be reduced compared with when the heating gas  11  only is used as the pyrolysis heat source. 
       Second Embodiment 
       [0064]    The following is a description of a second embodiment of the coal pyrolysis device according to the present invention based on  FIGS. 2A and 2B . 
         [0065]    The present embodiment is configured by modifying the deoxygenation device provided in the first embodiment as described above and illustrated in  FIG. 1 . The rest of the configuration is generally the same as that described above and illustrated in  FIG. 1 , so the same equipment is given the same reference numeral and duplicated descriptions are omitted as appropriate. 
         [0066]    As illustrated in  FIGS. 2A and 2B , a coal pyrolysis device  200  according to the present embodiment includes an inert gas generation device  240  that generates inert gas  24  for promoting the release of pyrolyzed gas  15  from dried coal  1 . 
         [0067]    The inert gas generation device  240  includes an exhaust gas extraction line  241  provided connected at a first end side (proximal end side) thereof between the second end side (distal end side) of the exhaust gas exhaust line  118  and the desulfurization device  133 . The second end side (distal end side) of the exhaust gas extraction line  241  is connected to a gas inlet of an alternating combustion deoxygenation device (deoxygenation device)  242 . A flow rate adjustment valve  241   a  and an extraction fan  241   b  are provided on the exhaust gas extraction line  241  from the first end side (proximal end side) thereof. By controlling the flow rate adjustment valve  241   a  and the extraction fan  241   b , a portion of the exhaust gas  13  that has passed through the desulfurization device  133  flows to the exhaust gas extraction line  241  via the exhaust gas exhaust line  118 . 
         [0068]    A first end side (distal end side) of an oxygen consuming fuel delivery line  245  that delivers an oxygen consuming fuel  27  for consuming oxygen in the exhaust gas  13 , for example, a hydrocarbon fuel such as natural gas, is provided connected in the vicinity of a gas inlet (a side wall in the vicinity of the top portion of a device main body  242   b  that is described later) of the alternating combustion deoxygenation device  242 . A tank  246  that stores the oxygen consuming fuel  27  is provided connected to a second end side (proximal end side) of the oxygen consuming fuel supply line  245 . A flow rate adjustment valve  245   a  is provided on the oxygen consuming fuel delivery line  245 . 
         [0069]    The alternating combustion deoxygenation device  242  includes the device main body  242   b  provided with a combustion chamber  242   a  in the interior thereof. A burner  242   c  is provided in the lower portion of the device main body  242   b . Temperature maintaining fuel  28  and temperature maintaining fuel combustion air  29  are supplied to the burner  242   c . The temperature maintaining fuel  28  is burned in the burner  242   c , thereby maintaining the temperature of the atmosphere in the combustion chamber  242   a  at a high temperature of about 1200° C. In this way, even when the concentration of oxygen in the exhaust gas  13  is a low concentration of 2 to 5%, the oxygen consuming fuel  27  can be stably burned with the low concentration of oxygen contained in the exhaust gas  13 . 
         [0070]    An alternating type heat exchanger  242   d  is provided in the device main body  242   b . The alternating type heat exchanger  242   d  includes a first heat exchanger main body  242   da  and a second heat exchanger main body  242   db  that are provided adjacently. The second end side (distal end side) of the exhaust gas extraction line  241  is connected to the first heat exchanger main body  242   da . A first end side (proximal end side) of an inert gas delivery line  247  is connected to the second heat exchanger main body  242   db . A rotary valve  242   e  is provided in the vicinity of the distal end side of the exhaust gas extraction line  241  and in the vicinity of the proximal end side of the inert gas supply line  247 , so that the distal end side of the exhaust gas extraction line  241  and the proximal end side of the inert gas delivery line  247  can be switched using the rotary valve  242   e . In this way, the exhaust gas  13  delivered to the alternating combustion deoxygenation device  242  from the exhaust gas extraction line  241  is preheated to 800° C. to 1000° C. by the alternating type heat exchanger  242   d  provided at the gas inlet of the alternating combustion deoxygenation device  242  and supplied to the combustion chamber  242   a  of the alternating combustion deoxygenation device  242 . 
         [0071]    By burning the oxygen consuming fuel  27  in the burner  242   c  together with the temperature maintaining fuel  28 , the oxygen in the exhaust gas  13  is consumed and the inert gas  24 , which is a gas with a low-oxygen concentration, is generated. 
         [0072]    A second end side (distal end side) of the inert gas delivery line  247  is connected to the first end side (proximal end side) of the inner cylinder  112  of the coal pyrolysis device main body  110 . In this way, the inert gas  24  whose temperature has become 70° C. to 150° C. in the alternating type heat exchanger  242   d  provided at the gas outlet of the alternating combustion deoxygenation device  242  is delivered to the inner cylinder  112  of the coal pyrolysis device main body  110 . 
         [0073]    An oxygen sensor (oxygen concentration measuring means)  247   a  capable of measuring the oxygen concentration of the inert gas  24  flowing through the inert gas delivery line  247  is provided on the inert gas supply line  247 . 
         [0074]    The oxygen sensor  247   a  is connected to the flow rate adjustment valve  245   a  provided on the oxygen consuming fuel delivery line  245  via an oxygen concentration signal cable. The degree of opening of the flow rate adjustment valve  245   a  can be adjusted on the basis of information (oxygen concentration of the inert gas  24 ) obtained by the oxygen sensor  247   a . In other words, the coal pyrolysis device  200  includes a control device (fuel addition control means) that is not illustrated on the drawings, and the control device can control the quantity of oxygen consuming fuel  27  added by the oxygen consuming fuel delivery line  245 , the flow rate adjustment valve  245   a , and the tank  246  so that the oxygen concentration of the inert gas  24  is, for example, 1.5% or less, on the basis of the information (oxygen concentration of the inert gas  24 ) obtained by the oxygen sensor  247   a.    
         [0075]    In the present embodiment as described above, exhaust means include the exhaust gas extraction line  241 , the flow rate adjustment valve  241   a , the extraction fan  241   b , and the like. Fuel addition means include the oxygen consuming fuel delivery line  245 , the flow rate adjustment valve  245   a , the tank  246 , and the like. Deoxygenation means include the alternating combustion deoxygenation device  242 , the fuel addition means, and the like. Low-oxygen concentration gas delivery means include the exhaust gas extraction line  241 , the flow rate adjustment valve  241   a , the extraction fan  241   b , the inert gas delivery line  247 , and the like. Low-oxygen concentration gas supply means include the low-oxygen concentration gas delivery means, the deoxygenation means, and the like. The coal pyrolysis device  200  includes the coal pyrolysis device main body  110 , the exhaust means, the gas extraction means, the low-oxygen concentration gas supply means, the fuel addition control means, and the like. The other means each include similar equipment as the first embodiment described above. 
         [0076]    In the coal pyrolysis device  200  according to the present embodiment that includes the inert gas generation device  240  as described above, it is possible to produce the pyrolyzed coal  2  from the dried coal  1  by causing the same central operation as the coal pyrolysis device  100  according to the first embodiment as described previously. 
         [0077]    Also, by controlling the flow rate adjustment valve  241   a  and the extraction fan  241   b  provided on the exhaust gas extraction line  241 , a portion of the exhaust gas  13  that has passed through the desulfurization device  133  via the exhaust gas exhaust line  118  is not exhausted outside the system but flows to the exhaust gas extraction line  241 . By controlling the flow rate adjustment valve  245   a  on the basis of the information (oxygen concentration of the inert gas  24 ) obtained from the oxygen sensor  247   a , a specific quantity of oxygen consuming fuel  27  is delivered to the alternating combustion deoxygenation device  242 . In other words, the oxygen concentration of the inert gas  24  can be reduced to a specific value or lower by feedback control. Preferably, the specific value is 1.5% or less. In this way, the pyrolysis loss due to the oxygen in the inert gas  24  reacting with the dried coal  1  can be minimized. 
         [0078]    By preheating the exhaust gas  13  to 800° C. to 1000° C. in the alternating type heat exchanger  242   d  and delivering it to the combustion chamber  242   a  within the alternating combustion deoxygenation device  242 , the temperature maintaining fuel  28  is burned together with the oxygen consuming fuel  27 , the oxygen within the exhaust gas  13  is consumed, and the oxygen concentration of the exhaust gas  13  is reduced. The temperature of the inert gas  24 , which is the exhaust gas  13  with a reduced oxygen concentration, becomes 70° C. to 150° C. in the alternating type heat exchanger  242   d , and is delivered to the inner cylinder  112  of the coal pyrolysis device main body  110  via the inert gas delivery line  247 . The quantity of inert gas  24  to be delivered is adjusted to 0.1 N·m 3  to 0.3 N·m 3  per 1 kg of dried coal  1  supplied to the inner cylinder  112 . In this way, the partial pressure of the pyrolyzed gas  15  at the surface of the dried coal  1  is reduced, which promotes the release of the pyrolyzed gas  15  from the dried coal  1 . 
         [0079]    In this way, in the present embodiment, by processing the exhaust gas  13  produced in the coal pyrolysis device main body  110  using the alternating combustion deoxygenation device  242 , it can be used as the inert gas  24  to promote the release of the pyrolyzed gas  15  from the dried coal  1 . 
         [0080]    Therefore, according to the coal pyrolysis device  200  of to the present embodiment, it is possible to process the exhaust gas  13  produced by the coal pyrolysis device main body  110  in the alternating combustion deoxygenation device  242  to obtain the inert gas  24 . The cost of the alternating combustion deoxygenation device  242  itself and the operating cost are lower than those of a PSA or cryogenic separation device, so the inert gas  24  that promotes release of the pyrolyzed gas  15  from the dried coal  1  can be obtained at low cost. 
         [0081]    Also, the temperature of the inert gas  24  obtained from the alternating combustion deoxygenation device  242  is about 70° C. to 150° C., so the dried coal  1  within the inner cylinder  112  is directly heated by the inert gas  24  in addition to being indirectly heated by the heating gas  11 . In other words, in addition to the heating gas  11 , the inert gas  24  can be used as the heat source (pyrolysis heat source) when pyrolyzing the dried coal  1 . In this way, the quantity of heat supplied from outside the coal pyrolysis device main body  110  as the pyrolysis heat source, in other words, the flow rate of the heating gas  11 , can be reduced, and the heat load of the coal pyrolysis device main body  110  can be reduced. As a result, the total length of the outer cylinder  113  (coal pyrolysis device main body  110 ) can be reduced compared with when the heating gas  11  only is used as the pyrolysis heat source. 
       Third Embodiment 
       [0082]    The following is a description of a third embodiment of the coal pyrolysis device according to the present invention based on  FIG. 3 . 
         [0083]    The present embodiment is configured by modifying the deoxygenation device provided in the first embodiment as described above and illustrated in  FIG. 1 . The rest of the configuration is generally the same as that described above and illustrated in  FIG. 1 , so the same equipment is given the same reference numeral and duplicated descriptions are omitted as appropriate. 
         [0084]    As illustrated in  FIG. 3 , a coal pyrolysis device  300  according to the present embodiment includes an inert gas generation device  340  that generates from the exhaust gas  13  inert gas (not illustrated on the drawings) for promoting the release of pyrolyzed gas  15  from the dried coal  1 . 
         [0085]    The inert gas generation device  340  includes an exhaust gas extraction line  341  provided connected at a first end side (proximal end side) thereof between the second end side (distal end side) of the exhaust gas exhaust line  118  and the desulfurization device  133 . 
         [0086]    A second end side (distal end side) of the inert gas supply line  341  is connected to the first end side (proximal end side) of the inner cylinder  112  of the coal pyrolysis device main body  110 . A flow rate adjustment valve  341   a  and an extraction fan  341   b  are provided on the exhaust gas extraction line  341  from the proximal end side thereof. 
         [0087]    In addition, a flow rate meter (exhaust gas flow rate measuring means)  341   c  that measures the flow rate of the exhaust gas  13  flowing through the exhaust gas extraction line  341 , and an oxygen sensor (oxygen concentration measuring means)  341   d  that measures the oxygen concentration of the exhaust gas  13  flowing through the exhaust gas extraction line  341  are provided on the exhaust gas extraction line  341 . 
         [0088]    In addition, a first end side (distal end side) of an oxygen consuming fuel supply line  345  that delivers an oxygen consuming fuel  37  for consuming oxygen in the exhaust gas  13 , for example a hydrocarbon fuel such as natural gas, is provided connected to the exhaust gas extraction line  341  between the oxygen sensor  341   d  and the second end side (distal end side) of the exhaust gas extraction line  341 . A tank  346  that stores the oxygen consuming fuel  37  is provided connected to a second end side (proximal end side) of the oxygen consuming fuel delivery line  345 . A flow rate adjustment valve  345   a  is provided on the oxygen consuming fuel delivery line  345 . 
         [0089]    The inert gas generation device  340  further includes a control device (computer)  348  connected to the flow rate meter  341   c  via a flow rate signal cable, connected to the oxygen sensor  341   d  via an oxygen concentration signal cable, and connected to the flow rate adjustment valve  345   a  via a control signal cable. The control device  348  controls the degree of opening of the flow rate adjustment valve  345   a  on the basis of information (flow rate of the exhaust gas  13 ) obtained from the flow rate meter  341   c  and information (oxygen concentration of the exhaust gas  13 ) obtained from the oxygen sensor  341   d , to adjust the supply flow rate of the oxygen consuming fuel  37  to be delivered to the exhaust gas extraction line  341 . 
         [0090]    In the present embodiment as described above, gas extraction means include the exhaust gas extraction line  341 , the flow rate adjustment valve  341   a , the exhaust fan  341   b , and the like. Fuel addition means include the oxygen consuming fuel delivery line  345 , the flow rate adjustment valve  345   a , the tank  346 , and the like. The gas extraction means and the like form heating gas delivery means. Low-oxygen concentration gas supply means include the heating gas delivery means, the fuel addition means, and the like. The control device  348  forms fuel addition quantity control means. The coal pyrolysis device  300  include the coal pyrolysis device main body  110 , the exhaust means, the gas extraction means, the low-oxygen concentration gas supply means, the fuel addition control means, and the like. The other means each include similar equipment as the first embodiment described above. 
         [0091]    In the coal pyrolysis device  300  according to the present embodiment that includes the inert gas generation device  340  as described above, it is possible to produce the pyrolyzed coal  2  from the dried coal  1  by causing the same central operation as the coal pyrolysis device  100  according to the first embodiment as described previously. 
         [0092]    Also, by controlling the flow rate adjustment valve  341   a  and the extraction fan  341   b  provided on the exhaust gas extraction line  341 , a portion of the exhaust gas  13  that has passed through the desulfurization device  133  is not exhausted outside the system but flows to the exhaust gas extraction line  341  via the exhaust gas exhaust line  118 . By controlling the flow rate adjustment valve  345   a  on the basis of information (flow rate of the exhaust gas  13 ) obtained from the flow rate meter  341   c  and information (oxygen concentration of the exhaust gas  13 ) obtained from the oxygen sensor  341   d , a specific quantity of the oxygen consuming fuel  37  is delivered to the first end side (proximal end side) of the inner cylinder  112  of the coal pyrolysis device main body  110  via the exhaust gas extraction line  341 . The control device  348  calculates the oxygen flow rate of the exhaust gas  13  on the basis of information (flow rate of the exhaust gas  13 ) obtained from the flow rate meter  341   c  and information (oxygen concentration of the exhaust gas  13 ) obtained from the oxygen sensor  341   d , and performs feedback control of the flow rate of the oxygen consuming fuel  37  so that the flow rate of the oxygen consuming fuel  37  is equal to or greater than equivalence of the calculated oxygen flow rate of the exhaust gas  13 , in other words, so that the excess oxygen ratio of the oxygen consuming fuel  38  is 1.0 or less. 
         [0093]    The inner cylinder  112  is heated by the heating gas  11  delivered to within the outer cylinder  113 , so the exhaust gas  13  and the oxygen consuming fuel  37  supplied to within the inner cylinder  112  is heated, the exhaust gas  13  and the oxygen consuming fuel  37  react in priority over the exhaust gas  13  and the dried coal  1 , so the oxygen in the exhaust gas  13  is consumed and the oxygen concentration of the exhaust gas  13  is reduced. By reducing the oxygen concentration of the exhaust gas  13 , it is used as inert gas within the inner cylinder  112 . 
         [0094]    In this way, in the present embodiment, the exhaust gas  13  produced by the coal pyrolysis device main body  110  is premixed with the oxygen consuming fuel  37 , and by heating the dried coal  1  during pyrolysis using the heat source, the oxygen in the exhaust gas  13  is consumed and its oxygen concentration is reduced, so it can be used as the inert gas to promote the release of the pyrolyzed gas  15  from the dried coal  1 . 
         [0095]    Therefore, according to the coal pyrolysis device  300  of the present embodiment, by adjusting the quantity of the oxygen consuming fuel  37  to be delivered to the exhaust gas  13  on the basis of information (flow rate of the exhaust gas  13 , oxygen concentration of the exhaust gas  13 ) regarding the exhaust gas  13  flowing through the exhaust gas extraction line  341 , so that the oxygen in the exhaust gas  13  within the inner cylinder  112  of the coal pyrolysis device main body  110  is burned by the oxygen consuming fuel  37  and the oxygen concentration is reduced, the inert gas can be obtained. The cost of the flow rate meter  341   c , the oxygen sensor  341   d , the oxygen consumption fuel supply line  345 , the flow rate adjustment valve  345   a , and the control device  348  and the operating cost are less compared with those of a PSA, a cryogenic separation device, or the like. Therefore, the inert gas that promotes release of the pyrolyzed gas  15  from the dried coal  1  can be obtained at low cost. 
         [0096]    The oxygen consuming fuel  37  reacts with the oxygen in the exhaust gas  13  within the inner cylinder  112  and generates heat, so during pyrolysis of the dried coal  1 , the heat of reaction between the oxygen in the exhaust gas  13  and the oxygen consuming fuel  37  can be used as a heat source (pyrolysis heat source) in addition to the heating gas  11 . In this way, the quantity of heat supplied from outside the coal pyrolysis device main body  110  as the pyrolysis heat source, in other words, the flow rate of the heating gas  11 , can be reduced, and the heat load of the coal pyrolysis device main body  110  can be reduced. As a result, the total length of the outer cylinder  113  (coal pyrolysis device main body  110 ) can be reduced compared with when the heating gas  11  only is used as the pyrolysis heat source. 
       OTHER EMBODIMENTS 
       [0097]    Note that in the above, the coal pyrolysis device  100 ,  200 ,  300  have been described with a single exhaust fan  118   c  provided in the exhaust gas exhaust line  118 , but a coal pyrolysis device in which a portion of the exhaust gas exhaust line  118  is divided into two systems, and an exhaust fan and a flow rate adjustment valve are provided in each system is also possible. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Dried coal 
           2  Pyrolyzed coal 
           11  Heating gas 
           12  Heating gas 
           13  Exhaust gas (mixed gas) 
           14  Inert gas (low-oxygen concentration gas) 
           15  Pyrolyzed gas (thermal decomposition gas) 
           16  Supporting fuel (combustion improver) 
           17  Oxygen consuming fuel 
           24  Inert gas (low-oxygen concentration gas) 
           27  Oxygen consuming fuel 
           28  Temperature maintaining fuel 
           29  Temperature maintaining fuel combustion air 
           37  Oxygen consuming fuel 
           110  Coal pyrolysis device main body 
           111  Hopper 
           112  Inner cylinder (main body trunk) 
           113  Outer cylinder (jacket) 
           114  Chute 
           115  Pyrolyzed gas exhaust line 
           116  Combustion furnace 
           117  Heating gas delivery line 
           118  Exhaust gas exhaust line 
           118   a  Boiler 
           118   b  Flow rate adjustment valve 
           118   c  Exhaust fan (outlet blower) 
           119  Heating gas bypass line 
           119   a  Boiler 
           119   b  Flow rate adjustment valve 
           121  Exhaust gas recirculation line 
           121   a  Flow rate adjustment valve 
           130  Exhaust gas processing device 
           131  Denitrification device 
           132  Electric dust collector 
           133  Desulfurization device 
           140  Inert gas generation device 
           141  Exhaust gas extraction line 
           141   a  Flow rate adjustment valve 
           141   b  Extraction fan (suction fan) 
           141   c  Temperature sensor 
           142  Combustion catalyst deoxygenation device (deoxygenation device) 
           143  Heat exchanger 
           144  Exhaust gas bypass line 
           144   a  Flow rate adjustment valve 
           145  Oxygen consuming fuel delivery line 
           145   a  Flow rate adjustment valve 
           146  Tank 
           147  Inert gas supply line 
           147   a  Oxygen sensor 
           240  Inert gas generation device 
           241  Exhaust gas extraction line 
           241   a  Flow rate adjustment valve 
           241   b  Extraction fan (suction fan) 
           242  Alternating combustion deoxygenation device (deoxygenation device) 
           242   a  Combustion chamber 
           242   b  Device main body 
           242   c  Burner 
           242   d  Alternating type heat exchanger 
           242   da  First heat exchanger main body 
           242   db  Second heat exchanger main body 
           242   e  Rotary valve 
           245  Oxygen consuming fuel delivery line 
           245   a  Flow rate adjustment valve 
           246  Tank 
           247  Inert gas delivery line 
           247   a  Oxygen sensor 
           340  Inert gas generation device 
           341  Exhaust gas extraction line 
           341   a  Flow rate adjustment valve 
           341   b  Extraction fan (suction fan) 
           341   c  Flow rate meter 
           341   d  Oxygen sensor 
           345  Oxygen consuming fuel delivery line 
           345   a  Flow rate adjustment valve 
           346  Tank 
           348  Control device (computer)