Abstract:
An apparatus and process for producing biocoke usable as a substitute fuel for coal coke from biomass as a raw material. The apparatus comprises pulverizing means for pulverizing a biomass raw material attributed to photosynthesis; heating means for heating to the temperature range in which the hemicellulose of the pulverized biomass raw material is pyrolyzed so as to exhibit bonding effects; pressurization means for, in the state of the heating, pressurizing to the pressure range in which the lignin of the pulverized biomass exhibits a thermal curing reaction and maintaining the pressure; and cooling means for cooling after maintaining the state of the pressurization. The apparatus further comprises temperature detecting means provided at the exit end of the region being heated by the heating means and regulation means for judging a reaction terminal point in accordance with the result of the temperature detection and regulating the timing for transfer from heating to cooling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to an apparatus and process for producing biocoke usable as a substitute fuel for coal coke from biomass as a raw material attributed to photosynthesis. 
         [0003]    2. Description of the Related Art 
         [0004]    In recent years, considering global worming which increase in carbon dioxide level is contributing to, predicted depletion of fossil fuel, renewable clean energy source, biomass has attracted attention. 
         [0005]    Biomass generally means renewable and biological organic resource excluding fossil fuels. By treating this biomass to carbonizaed gas, valuable resource such as heat, electricity, carbonized object can be obtained and biomass as waste is processed, which helps cleaning up the environment. Moreover, it is thought that as biomass is an organic matter, carbon dioxide caused from combustion of the biomass comes from carbon dioxide absorbed from the air by photosynthesis during the growth of biomass, thus causing no increase in carbon dioxide level in the air. This is called carbon neutral. Therefore, utilization of biomass is encouraged. 
         [0006]    On the other hand, due to fast growing demand for iron and steel in China, the cost of producing coal cokes is running up and significantly weighing on businesses of cast metal and iron makers in Japan. Therefore, solidified fuel with high hardness to replace a portion of coal cokes in manufacturing cast metal or iron is longed for, which can lower the fuel cost and suppresses the rise in carbon dioxide level in the air with carbon neutral characteristic of biomass. 
         [0007]    As a process to treat biomass to fuel, there are a production method of biomass water slurry disclosed in Patent Reference 1 (JP2003-129069A) and a method of converting raw garbage and sewer sludge into fuels disclosed in Patent Reference 2 (JP3613567B). 
         [0008]    However, neither of the inventions disclosed in Patent References 1 and 2 relates to the art of converting biomass into solidified fuel and cannot be used as a substitute of coal cokes. 
         [0009]    As a method for converting biomass into solid fuels, pellet production process is disclosed in Patent Reference 3. 
         [0010]    However, according to the method disclosed in Patent Reference 3 (JP52-101202A), a produced pellet has higher moisture content and does not have enough heat value to substitute for coal cokes. The produced pellet holds airspace therein, causing air (oxygen) to disperse within the pellet and shortening the combustion time, and among pulverized biomass no binding exists, causing the pallet to have insufficient hardness. 
         [0011]    Thus, it is difficult to use the produced pellet to substitute for coal cokes. 
         [0012]    Moreover, as another art of converting biomass into solid fuel, there are an art of shredding into small pieces and carbonizing a raw material (Patent Reference 4: JP2004-43517A), an art of producing a solid fuel having higher volume energy density and weight energy density than those of charcoal in a high energy yield (Patent Reference 5:JP2003-213273A), and an art of producing biomass semi-carbonized compressed fuel which improves transportability of ligneous biomass energy (Patent Reference 6: JP2003*206490A). Any of the solid fuels disclosed in Patent References 4 to 6 does not have very high heat value to substitute for coal cokes, or sufficient hardness, thus it is difficult to substitute coal cokes with those solid fuels. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention has been made in view of such problems as described above, and it is an object of the present invention to provide a biocoke producing apparatus and process for producing thereof, which uses biomasses as raw materials attributed to photosynthesis and can be used as substitute fuel for coal cokes. 
         [0014]    In order to solve the problems above, the present invention proposes a biocoke producing apparatus comprising: 
         [0015]    pulverizing means for pulverizing a biomass raw material attributed to photosynthesis; 
         [0016]    heating means for heating the biomass raw material pulverized by the pulverizing means to a temperature range in which hemicellulose of the pulverized biomass raw material is pyrolyzed so as to exhibit bonding effects; 
         [0017]    pressurization means for pressurizing the pulverized biomass in the state of the heating to a pressure range in which lignin of the pulverized biomass exhibits a thermal curing reaction and maintaining the pressure; and 
         [0018]    cooling means for cooling the pulverized biomass after maintaining the state of the pressurization: 
         [0019]    wherein said apparatus further comprises temperature detecting means provided at an exit end of the region being heated by the heating means and regulation means for judging a reaction terminal point in accordance with results of the temperature detection and regulating the timing for transferring from heating to cooling. 
         [0020]    The temperature detection means may be, but not limited to, contact or contactless as long as a thermometer is capable of detects the range of 100 to 250° C. with the speed to detects the timing for transfer from heating to cooling with precision in accordance with the result of the temperature. 
         [0021]    In this process, in order to obtain biocokes without excess process energy, it is preferably that the temperature condition at the heating means is 115 to 230° C. and the pressure condition at the pressurization means is 8 to 25 MPa, more preferably 180 to 230° C. and 12 to 19 MPa. By sustaining the temperature and pressure conditions for a certain period of time, biocokes can be obtained. The pressure and temperature ranges are sustained until judging the reaction terminal point in accordance with the result of the temperature detection and reaching the reaction terminal point. 
         [0022]    The reaction terminal point herein means a thermal hardening reaction point at which it reaches a target hardness as a biocoke by pyrolyzing the hemicellulose of the pulverized biomass so as to exhibit bonding effects, allowing lignin to react at a low temperature by superheated steam (developing inside the reaction cylinder of the piston-type extrusion equipment) in a state of maintaining its framework, and acting synergistically with consolidation effect (by means of the piston-type extrusion equipment). (The thermal hardening reaction makes progress as reaction activity spots are induced amongst phenolic macromolecules contained in lignin or the like.) 
         [0023]    Furthermore, the apparatus further comprises: 
         [0024]    a piston-type extrusion equipment for inputting said pulverized biomass: and 
         [0025]    regulating means which judges a reaction ending point based on results of the temperature detecting means and regulates extrusion speed of the piston-type extrusion equipment; 
         [0026]    wherein said heating means and cooling means are provided in the piston-type extrusion equipment, said heating means being located upstream of said cooling means; and said temperature detecting means is provided in the most downstream of said heating means. 
         [0027]    The biocoke producing apparatus is characterized in having; 
         [0028]    a filling container having a plurality of filling parts which penetrate through said container; and 
         [0029]    a filling means for filling said biomass raw material pulverized by said pulverizing means into said filling parts of said filing container; and 
         [0030]    regulating means for judging a reaction ending point from results of the temperature detecting means and regulating the extruding speed: 
         [0031]    wherein the biomass raw material filled in the plural filling pats of the filling container is extruded to the heating and cooling regions in sequence which are provided in the extrusion direction of the biomass raw material, said temperature detecting means is locating in the most down stream of the extrusion direction of the biomass raw material of the heating and pressurization means. 
         [0032]    The biocoke producing apparatus may also comprises: 
         [0033]    a plurality of reaction vessels circularly disposed, which comprises said pressurization means, said heating means, said cooling means and a discharging means for discharging a content after the cooling; and 
         [0034]    rotation means for rotating said plural reaction vessels disposed circularly along the periphery of the circle; and 
         [0035]    regulating means for judging a reaction terminal point in accordance with results of the temperature detection means and regulating the timing for transferring from the heating to the cooling so as to perform said filling, heating, pressurizing, cooling and discharging before said reaction vessels complete full circle while said rotation means rotates said plural reaction vessels along the periphery of the circle. 
         [0036]    The biocoke producing apparatus is also characterized in having: 
         [0037]    reaction vessel(s) having a jacket through which heating media or cooling media can run; 
         [0038]    filling means for filling biomass raw material pulverized by pulverizing means into said reaction vessel; and 
         [0039]    piston(s) for pressurizing the biomass raw material in said cylindrical vessel(s); 
         [0040]    wherein heating media are passed through said jacket for heating, and when sustaining the pressurized state in said piston, regulating means provided at the end inside of the cylindrical reaction vessel, which is furthest from the said piston, for judging a reaction terminal point in accordance with results of the temperature detection means and regulating the timing for switching fluid media being passed through said jacket from the heating media to the cooling media. 
         [0041]    With the use of the biocoke producing apparatus of the present invention, biocokes with maximum compressive strength of 60 to 200 MPa, maximum heat value of 18 to 23 MJ/kg and bulk specific gravity of approximately 1.4, which can be used as a substitute fuel for coal cokes, can be produced. 
         [0042]    Moreover, if the retention time of heated and pressurized state by heating means and pressurizing means respectively is short, biocoke is produced without completing the reaction, thus produced biocoke does not have sufficient strength, which leaves an issue about product quality. On the other hand, if the retention time is long, biocoke is produced completing the whole reaction, which does not leave an issue about product quality, but the production time for producing biocoke becomes longer than necessary. 
         [0043]    However, by providing the temperature detecting means at the exit end of the region being heated by the heating means, judging a reaction terminal point in accordance with the result of the temperature detection, and regulating the timing for transfer from heating to cooling, it is possible to retain the heated pressurized state until completing the reaction. Thus, biocoke with reliable quality can be produced. Also by judging the reaction terminal point and regulating the timing for transfer from heating to cooling, the retention time of the heated and pressurized state can be minimized. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0044]      FIG. 1  is a schematic view of a biocoke producing apparatus of the first embodiment. 
           [0045]      FIG. 2  is a schematic view of a biocoke producing apparatus of the second embodiment. 
           [0046]      FIG. 3  is a schematic view of a biocoke producing apparatus of the third embodiment. 
           [0047]      FIG. 4  is a schematic view of a biocoke producing apparatus of the fourth embodiment. 
           [0048]      FIG. 5  is a side view near a reaction vessel  70  according to the third and fourth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0049]    In an apparatus and process for producing biocoke according to the present invention, biomass used as raw material for producing biocoke is biomass raw material resulted from photosynthesis. The biomass may be ligneous matters, grass plant, crops, kitchen waste, or the like. 
         [0050]    In this invention, biomasses are all types of biomass which is attributed to photosynthesis in sunlight using water absorbed from roots and carbon dioxide in the air and forms organic matters such as sugar, cellulose and lignin. 
         [0051]    A preferred embodiment of the present invention will now be detailed with reference to the accompanying drawings. It is intended, however, that unless particularly specified, dimensions, materials, relative positions and so forth of the constituent parts in the embodiments shall be interpreted as illustrative only not as limitative of the scope of the present invention. 
       First Embodiment 
       [0052]      FIG. 1  is a schematic view of a biocoke producing apparatus of the first embodiment. 
         [0053]    After moisture content of biomass, which is a raw material, is controlled to 5 to 10%, the biomass is pulverized by a pulverizing means such as mixer to a grain diameter of 3 mm and below, preferably 0.1 mm and below, and fed to a receiving hopper  23 . 
         [0054]    Untreated biomass holds too much airspace and has small heat receiving surface, which is not ideal for thermal treatment. Therefore, it is important to pulverize the biomass prior to feeding to the receiving hopper  23  so as to allow homogeneous treatment. 
         [0055]    Biomass raw material fed to the receiving hopper  23  is extruded by screw extruders  21 ,  22  and sent to a piston-type extrusion equipment  10  equipped with a piston  20 . The piston-type extrusion equipment  10  is configured with three regions: thermal reaction region  11 , cooling region  11 , and pressure regulating region  13 . 
         [0056]    In the piston-type extrusion equipment  10 , not only the piston  20  extrudes biomass raw material, but pressure of a hydraulic cylinder  25  provided at the pressure regulating region  13  is regulated to 8 to 25 MPa, more preferably 12 to 19 MPa by controlling the torque of a extrusion piston  18  by PIC (pressure Interface Controller)  24 . 
         [0057]    The biomass raw material sent to the piston-type extrusion equipment  10  is first fed to the thermal reaction region  11 . In the thermal reaction region, the biomass raw material is heated to 115 to 230° C., preferably 180 to 230° C. In this embodiment, heating in the thermal reaction region  11  is done by an electric heater  14  so as to heat the temperature inside the cylinder of the thermal reaction region  11  to 115 to 230° C. (preferably 180 to 230° C.) by regulating a temperature of an outer surface of the cylinder (regulated to 115+α to 230+α (° C.) when heat transfer loss of the cylinder is a) by a heat source  15  controlled by TIC (Thermistor Interface Controller)  16 . However, a method of heating the outer surface of the thermal reaction region  11  does not matter as long as the outer surface is heated to 115 to 230° C., preferably 180 to 230° C. For example, oil bass whose temperature is regulated to 115 to 230° C. (preferably 180 to 230° C.) may be passed through the cylinder of the thermal reaction region  11 , or the cylinder of the thermal reaction region  11  may be covered by a jacket, through which a heating medium (such as silicon oil, steam and high-pressure heated water) with regulated temperature of 115 to 230° C. (preferably 180 to 230° C.) runs. 
         [0058]    Basically, in the thermal reaction region  11 , heating and press-molding of the biomass are carried out under the conditions of 115 to 230° C. and 8 to 25 MPa (preferably 180 to 230° C. and 12 to 19 MPa). 
         [0059]    By heating and press-molding the biomass under the above described conditions, biocoke having high hardness and high heat value can be obtained. By heating biomass at the temperature of 115 to 230° C. (preferably 180 to 230° C.), the hemicellulose which is one of the main components of the biomass raw material, is pyrolyzed and lignin reacts at a low temperature by means of superheated steam developed in the piston-type extrusion equipment  10 , maintaining its framework, and acts synergistically with consolidation effect, thereby improving the hardness. 
         [0060]    Moreover, as a characteristic configuration of the present invention, an infrared radiation thermometer  19  is provided at outlet end of the thermal reaction region  11 , which allows the thermometer to measure a temperature of a central part of the cylinder at the outlet end of the thermal reaction region  11 . It is configured such that the extrusion speed of the piston  20  is adjustable depending on the measured temperature at the central part of the cylinder. In this way, the retention time in the thermal reaction region  11 , which is the duration that biomass stays in the state of being heated and pressurized, can be optimized, thereby improving productivity and producing products of reliable quality. 
         [0061]    After carrying out the heating and the press-molding in the thermal reaction region  11 , the biocoke produced in the thermal reaction region  11  is extruded by the piston  20  to be transferred to the cooling region  12 . In the cooling region  12 , the biomass material is cooled to the range of 40 to 50° C. and below. The cooling in the cooling region  12  is performed by blowing air by means of an air blower  17  in the present embodiment but any method can be applied as long as an outer surface of the air cooling region  12  is cooled to the range of 40 to 50° C. and below. For example, an outer circumference of the cylinder in the cooling region  12  may be covered by a jacket, through which a cooling medium whose temperature is regulated to 40 to 50° C. can be passed. If the cooling temperature is higher than the above described temperature, the adhesion effect of hemicellulose decreases, resulting in lowering the hardness of the product. 
         [0062]    It is preferable that the cooling duration is about 30 to 60 minutes. If biocoke is cooled rapidly, it can cause a crack on the surface of the produced biocoke. 
         [0063]    After cooling the biomass material in the cooling region  12 , the biocoke cooled in the cooling region  12  is moved by the piston  20  to the outlet end of the piston-type extrusion equipment  10  through the pressure-regulating region  13  to be cut by a cutter  26  provided at the outlet end of the piston-type extrusion equipment  10  to a desired size so as to make biocoke products. 
       Second Embodiment 
       [0064]      FIG. 2  is a schematic view of a biocoke producing apparatus of the second embodiment. 
         [0065]    A moisture content of a biomass is regulated to 5 to 10% and then the biomass is pulverized so as to regulate the grain size to 3 mm and below, preferably 0.1 mm and below by a pulverizing means such as a mixer, and fed to a receiving hopper  33 . 
         [0066]    Untreated biomass holds too much airspace and has small heat receiving surface, which is not ideal for thermal treatment. Therefore, it is important to pulverize biomass prior to feeding to the receiving hopper  33  so as to allow homogeneous treatment. 
         [0067]    The biomass raw material fed to the receiving hopper  33 , is filled into two filling parts  31   a  and  31   b  of a filling cartridge  31  for a raw material by a screw extrusion equipment  33   a . In the embodiment, the filling cartridge  31  comprises two filling parts but one filling cartridge may have as many filling parts as needed. The filling cartridge  31  filled with raw material is installed in a multi-hydraulic system comprising two multi-pistons  32  and  42 . 
         [0068]    The multi-hydraulic system is configured such that the multi-piston  34  is fixed and the multi-piston  32  is movable so that the raw biomass filled in the filling parts  31   a  and  31   b  of the filling cartridge  31 , is extruded by cylinders  32   a  and  32   b  provided in the multi-piston  32 . Moreover, the pressure of the multi-piston  32  at the inlet side is regulated to 8 to 25 MPa, preferably 12 to 19 MPa by PIC  43 ; and the pressure of the multi-piston  34  at the outlet side is regulated by PIC  42  and ΔPIC  44  such that when extruding biomass raw material in the multi-hydraulic system, a pressure difference between the multi-piston  34  at the outlet side and the multi-piston  32  at the inlet side is 0.1 to 1.0 MPa, and the pressure of the multi-piston  34  at the outlet side is lower than the pressure of the multi-piston  32  at the inlet side. When biomass material in the multi-hydraulic system stays without being extruded, the pressure of the multi-piston  34  at the outlet side is regulated by PIC  42  and ΔPIC  44  such that a pressure difference between the multi-piston  34  at the outlet side and the multi-piston  32  at the inlet side is 0 MPa. 
         [0069]    The biomass raw material filled in the filling parts  31   a  and  31   b  of the raw material cartridge  31  is extruded by the cylinders  32   a  and  32   b , and moved through passages in the oil bath  35 . In the oil bath, the biomass raw material is heated to 115 to 230° C., preferably 180 to 230° C. The temperature of the oil in the oil bath  35  is regulated by pulling the oil from the oil bath  35  continuously to an oil warming bath  36 , the temperature in which is regulated to 115 to 230° C. (preferably 180 to 230° C.) by regulating a heat source  38  of a heater  39  for warming inside of the oil warming bath  36  by TIC  37 . In this embodiment, the oil bath is used to regulate the temperature to 115 to 230° C. (preferably 180 to 230° C.) but the heating method can be any one of heat transfer, resistance heating, high-frequency heating and radiation heating by means of fluid as long as being able to heat the raw material to 115 to 230° C. (preferably 180 to 230° C.). 
         [0070]    Briefly, in the passages inside the oil bath  35 , heating and press-molding of the biomass is performed under the conditions of 115 to 230° C. and 8 to 25 MPa (preferably 180 to 230° C. and 12 to 19 MPa). 
         [0071]    By heating and press-molding the biomass under the above described conditions, biocoke having high hardness and high heat value can be obtained. By heating biomass at a temperature of 115 to 230° C. (preferably 180 to 230° C.), the hemicellulose which is one of the main components of the biomass raw material, is pyrolyzed and lignin reacts at a low temperature by means of superheated steam developed in the passages, maintaining its framework, and acts synergistically with consolidation effect, thereby improving the hardness. 
         [0072]    Moreover, as a characteristic configuration of the present invention, a temperature sensor tip is provided at outlet end of the oil bath  35 , which allows measuring a temperature of a central part of the passages at the outlet end of the oil bath  35 . It is configured such that the extrusion speed is adjustable by regulating the pressure difference between the multi-piston  34  at the outlet end and the multi-piston  32  at the inlet end. In this way, the retention time in the region of the oil bath  35  can be optimized, thereby improving productivity and producing products of reliable quality. 
         [0073]    After heating and press-molding in the oil bath  35 , the biocoke produced by the pistons  32  and  34  is extruded and transferred to a cooling region in which the biocoke is cooled by an air blower  41 . The biomass raw material is cooled to the range of 40 to 50° C. and below by the air blower  41 . The cooling is performed by blowing air by means of an air blower  41  in the present embodiment but any method can be applied as long as the biomass raw material is cooled to the range of 40 to 50° C. and below. If the cooling temperature is higher than the above described temperature, the adhesion effect of hemicellulose decreases, resulting in lowering the hardness of the product. 
         [0074]    It is preferable that the cooling duration is about 30 to 60 minutes. If biocoke is cooled rapidly, it can cause a crack on the surface of the produced biocoke. 
         [0075]    The biocoke cooled by the air blower  41  is extruded by the pistons  32  and  34  and becomes a biocoke product. 
       Third Embodiment 
       [0076]      FIG. 3  is a schematic view of a biocoke producing apparatus of the third embodiment. 
         [0077]    After moisture content of biomass is regulated to 5 to 10%, biomass is pulverized by a pulverizing means such as mixer to a grain diameter of 3 mm and below, preferably 0.1 mm and below, and fed to a receiving hopper  53 . Depending on a type of biomass, it may require drying and/or pulverizing before regulating the moisture content. 
         [0078]    Untreated biomass holds too much airspace and has small heat receiving surface, which is not ideal for thermal treatment. Therefore, it is important to pulverize biomass prior to feeding to the receiving hopper  53  so as to allow homogeneous treatment. 
         [0079]    The biomass fed to the receiving hopper  53  is molded into a cylindrical pellet with bulk density of 0.9 to 1.0 by a compression molding press  52 . 
         [0080]    The biomass material molded into the cylindrical pellet is installed by a reacher  54  into one of fifty reaction vessels  70  disposed circularly on a press-reaction equipment  51 . 
         [0081]      FIG. 5  is a side view near the reaction vessel  70 . The biomass molded into the cylindrical pellet is installed into the reaction vessel  70 , and pressurized and compressed to 8 to 25 MPa, more preferably 12 to 19 MPa by means of an upper hydraulic cylinder  71 . The reaction vessel  70  and the upper hydraulic cylinder  71  rotate in a state of maintaining the pressure of 8 to 25 MPa (preferably 12 to 19 MPa), and move to a thermal reaction region  56  shown in  FIG. 3 . The heating in the thermal reaction region  56  can be carried out by continuously supplying a heat medium to a jacket  79  provided on the outer circumference of the reaction vessel  70  through a supply pipe  81   a  and discharging the heat medium continuously through a discharge pipe  82   a  so as to heat the biomass to 115 to 230° C., preferably 180 to 230° C. In this method, it is preferable to provide metal plates  77  and  78  made of material with high thermal conductivity such as silver and copper, at a bottom part of the upper cylinder  71  and at a bottom part of the reaction vessel  70  so as to make the heat transfer easier through the jacket  79  to the inside of the reaction vessel  70 . 
         [0082]    Basically, in the thermal reaction region  56 , biomass is heated and pressure-molded under the conditions of 115 to 230° C. and 8 to 25 MPa (preferably 180 to 230° C. and 12 to 19 MPa). 
         [0083]    By heating and press-molding the biomass under the above described conditions, biocoke having high hardness and high heat value can be obtained. By heating biomass at a temperature of 115 to 230° C. (preferably 180 to 230° C.), the hemicellulose which is one of the main components of the biomass raw material, is pyrolyzed and lignin reacts at a low temperature by means of superheated steam developed in the reaction vessel  70 , maintaining its framework, and acts synergistically with consolidation effect, thereby improving the hardness. 
         [0084]    Moreover, as a characteristic configuration of the present invention, a temperature sensor tip  83  is provided at lower end of the reaction vessel  70 , which allows the temperature sensor tip to measure a temperature of the lower end of the reaction vessel which is also a central part of the cylinder. By optimizing the rotation speed of the reaction vessel depending on the temperatures measured there, the retention time in which the reaction vessel  70  stays in the thermal reaction region  56  can be optimized, thereby improving productivity and producing products of reliable quality. 
         [0085]    After the heating and the press-molding in the thermal reaction region  56 , the reaction vessel rotates more maintaining the pressurized state of 8 to 25 MPa, and moved to a cooling region  57  shown in  FIG. 3 . It is possible to provide an insulating part between the thermal reaction region  56  and the cooling region  57 , which does not perform either of the heating or the cooling. The cooling in the cooling region  57 , in a similar manner as in the thermal reaction region  56 , can be done by continuously supplying a cooling medium to the jacket  79  provided on the outer circumference of the reaction vessel  70  through the supply pipe  81   a  and discharging the cooling medium continuously through the discharge pipe  82   a  so as to cool the biomass to 40 to 50° C. If the cooling temperature is higher than the above described temperature, the adhesion effect of hemicellulose decreases, resulting in lowering the hardness of the product. 
         [0086]    It is preferable that the cooling duration is about 30 to 60 minutes. If biocoke is cooled rapidly, it can cause a crack on the surface of the produced biocoke. 
         [0087]    After the cooling in the cooling region  57 , the reaction vessel  70  rotates more and moves to a position for a product-discharge conveyor  55 , the lower part of the reaction vessel  70  is opened, the cylindrical pellet of biocoke is extruded and discharged by the upper hydraulic cylinder  71  to the product discharge conveyor which is located below the reaction vessel  70 , and discharged by the product discharge conveyor  55  to a post process such as packing and shipping. 
       Fourth Embodiment 
       [0088]      FIG. 4  is a schematic view of a biocoke producing apparatus of the fourth embodiment. 
         [0089]    After moisture content of biomass is regulated to 5 to 10%, biomass is pulverized by a pulverizing means such as mixer to a grain diameter of 3 mm and below, preferably 0.1 mm and below, and fed to a receiving hopper  61 . 
         [0090]    Untreated biomass holds too much airspace and has small heat receiving surface, which is not ideal for thermal treatment. Therefore, it is important to pulverize biomass prior to feeding to the receiving hopper  61  so as to allow homogeneous treatment. 
         [0091]    Biomass raw material fed to the receiving hopper  61  travels on a traveling path  64  to be fed into the reaction vessel  70  through an input hole  62  for a raw material. The traveling path  64  is preferably a conveyor of sealed pipe-type so as to prevent the biomass material from being exposed to outside. 
         [0092]    The reaction vessel of this embodiment is the same as that of the third embodiment. Thus,  FIG. 5  is used herein as well for explaining the reaction vessel. 
         [0093]    In inputting biomass material to the reaction vessel  70 , firstly an upper gate  76   b  is opened, pulverized biomass being fed into an input vessel  73  from the traveling path  64  through the input hole  62  till the pulverized biomass reaches a location detecting sensor  74  for detecting the location of the pulverized biomass. Then, the upper gate  76   b  is closed, a lower gate  76  being opened so as to allow the reaction vessel to be filled with a certain amount of the pulverized biomass. 
         [0094]    The biomass raw material inputted into the reaction vessel  70  is pressurized and compressed to 8 to 25 MPa (preferably 12 to 19 MPa) by means of the upper hydraulic cylinder  71 . As the reaction vessel  70  and the upper hydraulic cylinder  71  remain in a state of the pressure of 8 to 25 MPa (preferably 12 to 19 MPa), the heating can be done by continuously supplying a heat medium to a jacket  79  provided on the outer circumference of the reaction vessel through a supply pipe  81   a  and discharging the heat medium continuously through a discharge pipe  82   a  so as to heat the biomass to 115 to 230° C., preferably 180 to 230° C. In this method, it is preferable to provide metal plates  77 ,  78  such as silver and copper with high thermal conductivity, at a bottom of the upper cylinder  71  and at a bottom of the reaction vessel  70  so as to make the heat transfer easier through the jacket  79  to the inside of the reaction vessel  70 . 
         [0095]    Basically, in a thermal reaction region  56 , biomass is heated and pressure-molded under the conditions of 115 to 230° C. and 8 to 25 MPa (preferably 180 to 230° C. and 12 to 19 MPa). 
         [0096]    By heating and press-molding the biomass material under the above described conditions, biocoke having high hardness and high heat value can be obtained. By heating biomass at a temperature of 115 to 230° C. (preferably 180 to 230° C.), the hemicellulose which is one of the main components of the biomass raw material, is pyrolyzed and lignin reacts at a low temperature by means of superheated steam developed in the reaction vessel  70 , maintaining its framework, and acts synergistically with consolidation effect, thereby improving the hardness. 
         [0097]    Moreover, as a characteristic configuration of the present invention, a temperature sensor tip  83  is provided at lower end of the reaction vessel  83 , which allows the temperature sensor tip to measure a temperature of the lower end of the reaction vessel which is also a central part of the cylinder. By optimizing the rotation speed of the reaction vessel depending on the temperatures measured at there, the heating duration can be optimized, thereby improving productivity and producing products of reliable quality. 
         [0098]    After the heating and the press-molding, the reaction vessel is cooled by replacing all the heating media with cooling media so as to cool the biomass to 40 to 50° C. while maintaining the pressurized state of 8 to 25 MPa. If the cooling temperature is higher than the above described temperature, the adhesion effect of hemicellulose decreases, resulting in lowering the hardness of the product. 
         [0099]    It is preferable that the cooling duration is about 30 to 60 minutes. If biocoke is cooled rapidly, it can cause a crack on the surface of the produced biocoke. 
         [0100]    After the cooling, the lower part of the reaction vessel  70  is opened and the cylindrical pellet of biocoke is extruded and discharged by the upper hydraulic cylinder  71  to the lower part of the reaction vessel  70 , thus to make a product. 
       INDUSTRIAL APPLICABILITY 
       [0101]    The present invention can be applied preferably to a production apparatus and method thereof for making biocokes of reliable quality in a short period of time, which can substitute for coal coke.