JP5656021B2 - Biomass pyrolysis apparatus and pyrolysis method - Google Patents

Description

  The present invention relates to a biomass pyrolysis apparatus and pyrolysis method for generating gas and tar from biomass in a pyrolysis furnace.

  A vertical gasification furnace (pyrolysis) that gasifies woody biomass (simply called biomass) derived from forest resources such as timber scrap, bark, wood chips, and thinned wood, and supplies the generated gas as fuel for a gas engine, for example Device) is disclosed in Non-Patent Document 1. In this gasification furnace, biomass is supplied from the upper part of the gasification furnace, and a packed moving bed in which biomass is deposited is formed in the gasification furnace. The packed moving bed forms a dry region, a pyrolysis region, a reduced region, and an oxidized region from the upper part, and the biomass descends from the upper part of the packed moving bed to the lower part as the gasification reaction proceeds. Further, steam and air are supplied as gasification agents from the lower part to the gasification furnace, and the gas flow in the gasification furnace flows from the lower part to the upper part of the gasification furnace in the packed moving bed, The product gas is taken out from the gas outlet at the top of the gasifier.

The biomass supplied from the upper part of the gasification furnace is dried by the heat of the gas generated in the packed moving bed in the gasification furnace to form a dry region in the upper part. Biomass descending from the drying region is pyrolyzed in the pyrolysis region, and combustible gases such as CH ₄ , CO, and H ₂ , product gases such as CO ₂ , H ₂ O, and gaseous tar, and fixed carbon are generated. Combustible gas and generated gas such as CO ₂ , H ₂ O, and gaseous tar rise, and fixed carbon falls. Fixed carbon descending from the pyrolysis region reacts steam and CO ₂ gasification as a gasifying agent in the reduction zone CO, to produce a H _2, CO, H ₂ rises to fill moving layer. In the oxidation area below the reduction area, the remaining fixed carbon, liquid tar, and unpyrolyzed biomass that have descended from the reduction area are partially oxidized and burned by air, generating heat necessary for gasification, pyrolysis, and drying. The combustion gas rises with heat. Combustion ash is discharged outside from the bottom of the packed moving bed.

  In addition, it is being studied to pyrolyze biomass to take out tar and use it as an alternative fuel for heavy oil. When producing tar by pyrolyzing biomass, gas-bed pyrolysis is a method with high tar yield. Rapid pyrolysis processes using an apparatus (Patent Document 1) and a fluidized bed pyrolysis apparatus (Patent Document 2) are known.

JFE Engineering Company Catalog (Cat. No. CA3047) “JFE-Felt type woody biomass gasification power generation system” issued by JFE Engineering Corporation, 2004

JP 2010-116536 A Japanese Patent No. 4371433

  However, in the processes according to Patent Document 1 and Patent Document 2, the viscosity of the obtained tar is high, which causes a clogging trouble in the tar recovery device, and handling of liquid feeding and the like in the utilization process is difficult. Further, tar is obtained as a by-product from the packed moving bed gasification furnace of Non-Patent Document 1, but the tar yield (ratio of the generated tar weight to the dry weight of the raw material biomass) is about 5 to 7%. It was low and was not sufficient in terms of tar production capacity.

  The present invention has been made in view of such circumstances, and is capable of producing tar from biomass with a high tar yield, and further capable of producing a large amount of tar with low viscosity. It is another object of the present invention to provide a thermal decomposition method.

  In the method of Non-Patent Document 1, the inventors of the present invention have reported that the gaseous tar or mist tar generated in the pyrolysis region and rising to the drying region is cooled and condensed in the drying region to become a liquid tar or agglomerated to form large particles. It becomes a liquid tar with a diameter and is captured by adhering to the biomass, and the biomass is lowered and returned to the thermal decomposition region. In this way, since most of the tar generated in the pyrolysis zone is captured in the drying zone, there is little tar discharged with the product gas from the top of the pyrolysis furnace, and the tar yield is as low as about 5 to 7%. I found out.

  As a result of studying to improve the tar yield using the biomass gasification furnace of Non-Patent Document 1, the present inventors have reduced the bed height of the packed moving bed and introduced the gas from the bottom of the furnace. By increasing the agent flow rate, the tar yield, which was 5-7% in the method of Non-Patent Document 1, could be increased to 20%. This was comparable to the tar yield obtained with a gas-bed pyrolysis furnace, and a tar having a significantly lower viscosity was obtained.

  The inventors considered the results of this study, and reduced the bed height of the packed moving bed and increased the gasifying agent flow rate introduced from the lower part of the furnace to increase the layer thickness of the dry region that captures most of the tar. It has been found that most of the tar generated in the pyrolysis region can be passed through in the drying region so as to reduce the size of the material. That is, reducing the layer thickness in the dry region as much as possible is effective for improving the tar yield. On the other hand, when the layer thickness of the dry region is reduced, it was also confirmed that there is a lower limit of the layer thickness necessary for applying a sufficient pressure downward to suppress the occurrence of shelf hanging of biomass in the pyrolysis region. Here, the biomass shelf suspension means that biomass or pyrolysis residue during the pyrolysis is fused to the inner wall of the furnace, and the shelf is suspended. There arises a problem that the distribution of the gas in the furnace is hindered and the stable operation cannot be performed. When the layer thickness of the drying region is too small, the pressure for lowering the biomass in the pyrolysis region is insufficient, and there arises a problem that the biomass and the pyrolysis residue are accumulated to cause shelf hanging.

  Under such circumstances, in order to solve the problems, the present invention has led to a first invention for a device having the following structure and a second invention for a method.

<First invention (device invention)>
Biomass is supplied from the upper part of the vertical pyrolysis furnace to form a packed moving bed of biomass in the pyrolysis furnace, and is supplied with a gasifying agent from the lower part of the pyrolysis furnace, and the biomass that falls in the packed moving bed In a biomass pyrolysis apparatus equipped with a pyrolysis furnace in which a product gas and tar are obtained by being pyrolyzed by causing countercurrent contact with a rising gasifying agent,
Formed from the top to the bottom of the packed moving bed in order, the drying area for drying the supplied biomass, the pyrolysis area for pyrolyzing the biomass to produce gas and tar, and the fixed carbon generated by pyrolysis as gas Among the oxidation region that generates the heat necessary for the gasification reaction by partially oxidizing the reduced region and the unburned fixed carbon and biomass, the dry region layer thickness adjusting means for adjusting the layer thickness of the dry region, The dry region layer thickness adjusting means adjusts the layer thickness of the dry region to the layer thickness of the dry region necessary for applying sufficient pressure to the lower layer to suppress the occurrence of biomass shelving in the pyrolysis region. It is set to be above the lower limit and to be adjusted below the upper limit of the layer thickness of the drying region so that the biomass is dried in the drying region and most of the tar generated in the pyrolysis region is allowed to pass through. And pyrolyzer biomass, characterized in that are.

  In the present invention, if the layer thickness in the drying region is smaller than the lower limit, the pressure for lowering the biomass in the pyrolysis region is insufficient, and biomass in the middle of pyrolysis and biomass pyrolysis residue are retained and fused to the furnace wall before long. If pyrolysis of biomass does not proceed smoothly and the layer thickness of the drying zone is larger than the upper limit, the gaseous tar or mist tar generated in the pyrolysis zone is cooled and condensed in the drying zone to become liquid tar. Or it aggregates and becomes a large particle size liquid tar, adhere | attaches on biomass, etc., most tars are capture | acquired, and the amount of tar discharged | emitted from a pyrolysis furnace decreases. Therefore, in the present invention, the layer thickness is adjusted so as to be between the upper limit and the lower limit.

  In the present invention, the dry region layer thickness adjusting means includes, for example, a biomass supply amount adjusting device and a gasifying agent supply amount adjusting device, and can adjust the layer thickness of the dry region.

  The biomass supply amount adjusting device adjusts the biomass supply amount to adjust the bed height of the packed moving bed, and further, the dry region layer thickness is set to a pressure sufficient to suppress the occurrence of biomass shelving in the pyrolysis region. The layer of the drying region is set to be equal to or more than the lower limit of the layer thickness of the drying region necessary for supplying the lower layer, and the biomass is dried in the drying region and most of the tar generated in the pyrolysis region is allowed to pass through. Adjust below the upper limit of thickness. In this way, adjusting the layer thickness of the dry region can be achieved by lowering the layer height of the packed moving bed compared to the case where the packed moving bed pyrolyzer is mainly used as a gasifier for generating gas. This corresponds to reducing the thickness. In addition, the gasifying agent supply amount adjusting device has a dry region layer thickness of a dry region layer thickness necessary for applying a sufficient pressure to the lower layer to suppress the occurrence of biomass shelving in the pyrolysis region. While not less than the lower limit, the biomass is dried in the drying region, and adjusted to be equal to or less than the upper limit of the layer thickness of the drying region so that most of the tar generated in the pyrolysis region passes. In this way, adjusting the layer thickness of the dry region increases the gasification agent supply amount compared to the case where the packed moving bed pyrolyzer is used as a gasifier that mainly generates gas, This corresponds to increasing the layer thickness of the reduction region and the oxidation region and, as a result, adjusting to reduce the dry region layer thickness.

  By setting the layer thickness of the drying region to an appropriate range by the biomass supply amount adjusting device and the gasifying agent supply amount adjusting device, the gaseous or mist tar generated in the pyrolysis region and raised to the drying region is It does not condense and become liquid or aggregate in the drying area, is trapped and returned to the pyrolysis area, passes through the drying area in the form of gas or mist, and is discharged from the upper part of the pyrolysis furnace.

  In the present invention, the biomass supply amount adjustment device and / or the gasifying agent supply amount adjustment device preferably sets the temperature of the drying region to 80 ° C. or more and 100 ° C. or less.

  In the present invention, the gasification agent supply amount adjusting device sets the superficial gas linear velocity to 40 to 60 cm when the gasification agent rises in the pyrolysis furnace at 1000 ° C. when the contents in the pyrolysis furnace are absent. It is preferable to set to / s.

<Second invention (method invention)>
Biomass is supplied from the upper part of the vertical pyrolysis furnace to form a packed moving bed of biomass in the pyrolysis furnace, and is supplied with a gasifying agent from the lower part of the pyrolysis furnace, and the biomass that falls in the packed moving bed In a biomass pyrolysis method in which a product gas and tar are obtained by countercurrent contact with a rising gasifying agent and pyrolyzing,
In order from the top to the bottom of the packed moving bed, the drying area for drying the supplied biomass, the pyrolysis area for pyrolyzing the biomass to produce gas and tar, and the reduction for gasifying the fixed carbon generated by pyrolysis The region and unburned fixed carbon and biomass are partially oxidized to form an oxidation region that generates the heat required for the gasification reaction, and the layer thickness of the drying region is reduced, and the occurrence of biomass shelving in the pyrolysis region is suppressed. In order to apply a sufficient pressure to the lower layer in order to exceed the lower limit of the layer thickness of the drying region, the biomass is dried in the drying region and most of the tar generated in the pyrolysis region is allowed to pass through. The biomass pyrolysis method is characterized in that the temperature is adjusted below the upper limit of the layer thickness of the dry region.

  Also in the second invention, the adjustment of the layer thickness in the dry region is performed by adjusting the biomass supply amount or the gasifying agent supply amount, as in the case of the first invention.

  As described above, the present invention is to apply a sufficient pressure to the lower layer to suppress the occurrence of the shelf hanging of the biomass in the pyrolysis region, and the layer thickness of the drying region in the upper part of the packed moving bed of biomass. Adjust to below the upper limit of the layer thickness of the drying zone so that the bulk of the tar generated in the pyrolysis zone is allowed to pass through while drying the biomass in the drying zone while making it not less than the lower limit of the required drying zone thickness. Therefore, it is possible to provide a biomass pyrolysis apparatus and method capable of producing tar with high yield. Furthermore, since the temperature of the drying region is set to 80 ° C. or more and 100 ° C. or less, a tar having a low condensation temperature, that is, a tar having a low viscosity is selectively passed in the drying region, so that a tar having a low viscosity is obtained to the maximum. Biomass pyrolysis apparatus and method can be provided.

It is a schematic block diagram of the apparatus of one Embodiment of this invention.

  FIG. 1 is a schematic configuration diagram of a biomass pyrolysis apparatus as one embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a pyrolysis furnace formed as a vertical furnace. Connected to the upper part of the pyrolysis furnace 1 is a biomass supply apparatus 2 that cuts biomass stored in a hopper or the like by a cutting device such as a rotary valve, conveys the biomass by a conveyor or the like, and supplies the biomass to the upper space in the furnace. In addition, a gas discharge port 3 for discharging the generated gas from the upper space is provided. A cooler 4 is connected to the gas discharge port 3, and a specific gravity separator 5 is connected to the cooler 4. The cooler 4 receives the generated gas from the gas discharge port 3 and cools the generated gas by heat exchange with the cooling medium. By cooling, the tar and water as liquid components and after cooling In addition, gas-liquid separation is performed into combustible gas as the remaining gas. The specific gravity separator 5 connected to the cooler 4 is, for example, a centrifugal separator, and tar and water received from the cooler 4 are converted into light tar, water, and heavy tar due to a difference in specific gravity. It comes to separate.

  The pyrolysis furnace 1 receives air and water vapor as gasifying agents from its lower part. A humidifier 6 is connected to the lower part of the furnace, air is sent to the humidifier 6 by the blower 7 and steam is sent to the humidifier 6 by the blower 8, mixed with each other, and sent from the humidifier 6 to the lower part of the furnace.

  In the apparatus of this embodiment, as a preferred embodiment, temperature sensors for detecting the temperature of the packed moving bed of biomass in the furnace and the temperature of the gas discharged from the packed moving bed are distributed over the furnace wall. In addition, a bed height sensor is installed to measure the bed height of the packed moving bed of biomass. With the outputs of the temperature sensor and the bed height sensor, a dry region layer thickness adjusting device including a biomass supply amount adjusting device and a gasifying agent supply amount adjusting device, which will be described later, is operated. In the present embodiment, the biomass supply device 2 includes a biomass supply amount adjustment device (not shown) such as a rotary valve that adjusts and cuts out the biomass, and adjusts the biomass supply amount to the pyrolysis furnace 1. It can be done. Further, a blower 7 for blowing air and a blower 8 for blowing water vapor are installed as a gasifying agent supply amount adjusting device so that the supply amounts of air and water vapor as the gasifying agent can be adjusted. A damper may be provided in a duct that blows air and water vapor, and the supply amount may be adjusted by the opening degree of the damper.

  In the apparatus of this embodiment having such a configuration, biomass is pyrolyzed in the following manner to obtain tar.

<Pyrolysis furnace>
When biomass is supplied from the upper part of the pyrolysis furnace 1 to the pyrolysis furnace 1 by the biomass supply device 2, a packed moving bed in which the biomass is deposited in the pyrolysis furnace 1 is formed. The packed moving bed forms a dry region, a pyrolysis region, a reduction region, and an oxidation region from the upper part, and the biomass descends from the upper part of the packed moving layer to the lower part as the pyrolysis reaction proceeds. Suitable temperatures in each zone are 80-100 ° C. in the dry zone, 150-800 ° C. in the pyrolysis zone, 800-1100 ° C. in the reduction zone, and 1100-1300 ° C. in the oxidation zone.

  From the lower part of the pyrolysis furnace 1, air and water vapor fed by the blowers 7 and 8 as gasification agents are mixed in the humidifier 6 and then supplied into the furnace, and the air-fuel mixture passes through the pyrolysis furnace 1 from the lower part. It rises to the oxidation region, the reduction region, and the thermal decomposition region. In the oxidation region, fixed carbon, liquid tar, and unpyrolyzed biomass are partially oxidized and burned by the gas mixture, generating heat necessary for gasification reaction, pyrolysis, and drying. To rise. In the reduction region, the biomass is thermally decomposed by the heat of the combustion gas, and the product gas generated from the biomass is taken out from the upper gas discharge port 3.

Biomass that is supplied from the top of the pyrolysis furnace 1 and forms a packed moving bed in the pyrolysis furnace 1 is dried by the heat of the generated gas to form a dry region on the top of the packed moving bed. Biomass descending from the drying region is pyrolyzed in the pyrolysis region, and combustible gases such as CH ₄ , CO, and H ₂ , product gases such as CO ₂ , H ₂ O, and gaseous tar, and fixed carbon are generated. Combustible gas and produced gas such as CO ₂ , H ₂ O, and gaseous tar rise in the packed moving bed, and fixed carbon falls. Fixed carbon, liquid tar, and unpyrolyzed biomass descending from the pyrolysis region gasify and react with water vapor or CO ₂ as a gasifying agent in the reduction region to produce CO and H _2, and the generated CO and H ₂ Rises in the packed moving bed. In the oxidation region formed below the reduction region, the remaining fixed carbon, liquid tar, and unpyrolyzed biomass that have descended from the reduction region are partially oxidized and burned by air, which is necessary for gasification, thermal decomposition, and drying. Heat is generated, and the combustion gas rises in the packed moving bed with heat and supplies heat for pyrolysis of biomass in the pyrolysis region. Combustion ash is discharged to the outside from the lower part of the packed moving bed.

<Adjustment of layer thickness in dry area>
The biomass pyrolysis treatment amount (amount per unit time) is defined by the supply amount of the gasifying agent, and a predetermined treatment amount is set. Correspondingly, when the height of the filling moving layer is set, the height of the drying area corresponding to this is set, and the upper and lower limit range (standard layer thickness range) of the drying area is set. The

  Temperature sensors are distributed in the vertical direction on the furnace wall of the pyrolysis furnace, and the temperature distribution of the packed moving bed in the height direction can be obtained. Further, the position (layer height) of the upper surface of the filling moving layer is obtained from the layer height sensor. From the temperature distribution and the layer height, the aforementioned range of 80 to 100 ° C. is recognized as the dry region. Thus, the layer thickness of the dry region is detected. The detection layer thickness is compared with the above standard layer thickness range, and the biomass supply amount adjustment device and the gasifying agent supply amount adjustment device as the dry region layer thickness adjustment device so that the detection layer thickness is within the standard layer thickness range. Adjust the operation. That is, the layer thickness of the drying region is set to be equal to or more than the lower limit of the standard layer thickness necessary for applying downward pressure sufficient to suppress the occurrence of biomass shelving in the pyrolysis region, and the biomass in the drying region Dry and adjust below the upper limit to pass most of the tar produced in the pyrolysis zone. If the layer thickness of the drying zone is smaller than the above lower limit, the pressure for lowering the biomass from the pyrolysis zone to the reduction zone is insufficient, and the biomass stays in the pyrolysis zone and the pyrolysis residue of biomass and biomass during the pyrolysis remains in the furnace wall. This is because a problem arises in the operation of the pyrolysis furnace due to the occurrence of the shelf hanging.

  In such adjustment, if the detection layer thickness in the dry region is larger than the standard layer thickness range, or the upper surface height of the dry region, that is, the height of the packed moving layer is too high, the biomass supply adjustment device is When the biomass supply amount is reduced by operation, and this is not sufficient, the gasification agent supply amount adjusting device is also operated to increase the supply amount of the gasification agent so that the layer thickness of the dry region is less than the upper limit.

  Thus, by the biomass supply amount adjusting device, the biomass supply amount is adjusted and the bed height of the packed moving bed is adjusted, or the dry region layer thickness is adjusted, but when the operation of the biomass pyrolysis furnace is started, Biomass is supplied to form a packed moving bed so as to have a predetermined packed moving bed height, and after the start-up operation ends and the operation shifts to a steady operation, the predetermined packed moving bed height is maintained. The biomass supply amount is adjusted so that the dry region layer thickness is a preferable layer thickness.

  In addition, depending on the gasification agent supply amount adjusting device, the gasification agent supply amount is increased to increase the layer thickness of the pyrolysis region, the reduction region, and the oxidation region, thereby reducing the dry region layer thickness. It adjusts so that it may become a preferable layer thickness.

  Thus, most of the gaseous or mist tar generated in the pyrolysis zone and rising to the dry zone does not condense into a liquid tar or agglomerate into a large particle size liquid tar in the dry zone. Instead of being captured and returned to the pyrolysis zone, it passes through the drying zone in a gaseous or mist form and is discharged from the pyrolysis furnace. Increasing the gasification agent supply amount decreases the dry area layer thickness and reduces the amount of trapped tar and improves the tar yield. However, if the gasification agent supply amount is increased excessively, the gas in the furnace rises. By increasing the speed, the downward movement of biomass and the like constituting the packed moving bed is hindered, and the drift of the in-furnace gas and the shelves are eventually generated.

  Regarding the temperature of the drying region, the temperature of the drying region is set to 80 ° C. by adjusting the biomass supply amount with the biomass supply amount adjusting device and / or adjusting the gasifying agent supply amount with the gasifying agent supply amount adjusting device. The temperature is maintained at 100 ° C or lower, more preferably 80 ° C or higher and 90 ° C or lower. By maintaining the temperature in the drying region in this way, the high molecular weight tar having a high boiling point and high viscosity is condensed, and the biomass charged at room temperature and covering the top of the packed bed serves as a filter for the condensed high molecular weight tar. Is trapped, so that the ratio of the tar having a high viscosity to the tar discharged from the gas discharge port is reduced. Therefore, the tar obtained has a low viscosity. This avoids troubles caused by high viscosity tar. Further, when the height of the packed moving bed is lowered and the layer thickness of the drying region is adjusted so as to pass most of the tar generated in the pyrolysis region, the tar is obtained in a high yield. By maintaining the temperature of the drying region within the above range, the tar obtained can be made into a low-viscosity tar and a low-viscosity tar can be obtained in a high yield.

In this way, the kinematic viscosity of the tar obtained in the vertical pyrolysis furnace of the present embodiment is about ^{100 mm 2 / s (50 ℃} ), the tar obtained in the stream bed reactor 500 to 1000 mm ² Compared with / s (50 ° C.), the value is 1/5 or less, and it is easy to handle because of its low viscosity.

  In the present embodiment, the gasification agent supply amount adjusting device sets the superficial gas linear velocity to 40 to 40 when the gasification agent rises at 1000 ° C. in the pyrolysis furnace when the contents in the pyrolysis furnace are absent. More preferably, it is set in the range of 60 cm / s. If it is lower than the lower limit of this range, when the layer thickness of the dry region is reduced so as to pass most of the tar, the layer height becomes too low and becomes below the lower limit of the standard layer thickness. Moreover, if it is higher than the upper limit of this range, the downward movement of biomass and the like constituting the packed moving bed will be prevented, and in-furnace gas drift and shelves will eventually occur.

<Processing of generated gas>
In this way, the product gas produced in the pyrolysis furnace 1 and taken out from the gas outlet 3 is brought to the cooler 4 where the tar and moisture are aggregated by cooling and separated into gas and liquid. The liquid component is sent to the specific gravity separator 5, and the remaining product gas component is sent out from the cooler 4 as combustible gas and used for fuel and the like. On the other hand, the liquid component is taken out after being separated into light tar, water, and heavy tar by the specific gravity separator 5 by the specific gravity difference. Heavy tar (water-insoluble tar) can be used as an alternative fuel for C heavy oil.

  Hereinafter, examples using the apparatus of the present embodiment will be shown together with comparative examples.

  In each embodiment, the height of the packed moving bed in the vertical pyrolysis furnace is set to be about 60% of the height of the packed moving bed in the normal gasification operation performed using this pyrolysis furnace. The biomass supply amount was adjusted. While the height of the packed moving bed at the time of normal gasification operation as shown in the comparative example is 3.2 m, in Examples 1 to 4, the height is 1.9 m, which is 60%, and the dry region layer While the thickness was reduced, the biomass supply amount, the gasifying agent supply amount, and the superficial gas linear velocity were variously changed. As a result, high tar yield and tar yield as shown in Table 1 were obtained.

<Comparative example>
In a vertical pyrolysis furnace (furnace inner diameter 300 mm), the height of the packed moving bed at the time of gasification operation was set to 3.2 m, and the layer thickness of the dry region was set to 2.2 m. Most of the tar was trapped in the dry zone and the tar yield was 4.2 wt%.

<Example 1>
The layer height of the packed moving layer was reduced to 60% of the comparative example, and the layer thickness of the dry region was set to 0.9 m, which is about 40% of the comparative example. The biomass supply amount and the gasifying agent supply amount were the same as in the comparative example. It was confirmed that by reducing the layer thickness in the dry region, most of the tar was allowed to pass and the tar yield was increased to 7.7 wt%, 1.8 times that of the comparative example.

<Example 2>
Compared to Example 1, the biomass supply amount and the gasification agent supply amount were each increased by 1.4 times, and the tar yield was 13.7 wt%, which was 3.3 times that of the comparative example. .

<Example 3>
Compared to Example 1, the biomass supply amount is increased by 1.9 times, the gasifying agent supply amount is increased by 1.8 times, and the tar yield is increased by 18.2% by weight to 4.3 times that of the comparative example. I was able to.

<Example 4>
Compared to Example 1, the biomass supply amount is increased 1.9 times, the gasifying agent supply amount is increased twice, and the tar yield is increased to 20.1 wt%, which is 4.8 times that of the comparative example. did it. Shelf hanging occurred when the gas agent feed rate was higher than 60 cm / s.

1 Pyrolysis furnace 2 Biomass supply amount adjustment device (biomass supply device)
7 Gasification agent supply amount adjustment device (air blower)
8 Gasification agent supply amount adjustment device (steam blower)

Claims (5)

Biomass is supplied from the upper part of the vertical pyrolysis furnace to form a packed moving bed of biomass in the pyrolysis furnace, and is supplied with a gasifying agent from the lower part of the pyrolysis furnace, and the biomass that falls in the packed moving bed In a biomass pyrolysis apparatus equipped with a pyrolysis furnace in which a product gas and tar are obtained by being pyrolyzed by causing countercurrent contact with a rising gasifying agent,
Formed from the top to the bottom of the packed moving bed in order, the drying area for drying the supplied biomass, the pyrolysis area for pyrolyzing the biomass to produce gas and tar, and the fixed carbon generated by pyrolysis as gas Among the oxidation region that generates the heat necessary for the gasification reaction by partially oxidizing the reduced region and the unburned fixed carbon and biomass, the dry region layer thickness adjusting means for adjusting the layer thickness of the dry region, The dry region layer thickness adjusting means adjusts the layer thickness of the dry region to the layer thickness of the dry region necessary for applying sufficient pressure to the lower layer to suppress the occurrence of biomass shelving in the pyrolysis region. a lower limit above, the dried biomass in the drying zone, without resulting gaseous or mist-like tar is captured by condensation or aggregate in the pyrolysis area, gaseous or Mi tar Pyrolyzer biomass, characterized in that is configured to adjust the following preparative shaped leave the layer thickness of the upper limit of the drying zone drying area to pass.   The biomass pyrolysis apparatus according to claim 1, wherein the dry region layer thickness adjusting means includes a biomass supply amount adjusting device and a gasifying agent supply amount adjusting device. The biomass pyrolysis apparatus according to claim 1 or 2, wherein the biomass supply amount adjusting device and / or the gasifying agent supply amount adjusting device sets the temperature of the drying region to 80 ° C or more and 100 ° C or less.   The gasification agent supply amount adjustment device sets the superficial gas linear velocity to 40-60 cm / s when the gasification agent rises in the pyrolysis furnace at 1000 ° C. when the contents in the pyrolysis furnace are absent. The biomass pyrolysis apparatus according to any one of claims 1 to 3. Biomass is supplied from the upper part of the vertical pyrolysis furnace to form a packed moving bed of biomass in the pyrolysis furnace, and is supplied with a gasifying agent from the lower part of the pyrolysis furnace, and the biomass that falls in the packed moving bed In a biomass pyrolysis method in which a product gas and tar are obtained by countercurrent contact with a rising gasifying agent and pyrolyzing,
In order from the top to the bottom of the packed moving bed, the drying area for drying the supplied biomass, the pyrolysis area for pyrolyzing the biomass to produce gas and tar, and the reduction for gasifying the fixed carbon generated by pyrolysis The region and unburned fixed carbon and biomass are partially oxidized to form an oxidation region that generates the heat required for the gasification reaction, and the layer thickness of the drying region is reduced, and the occurrence of biomass shelving in the pyrolysis region is suppressed. a enough pressure over the lower limit of the layer thickness of the dried area necessary to provide the layer below in order, together with the drying of the biomass in the drying zone, the gaseous or mist tar produced in the pyrolysis region condensed or aggregated without being captured, tar to and adjusting the following layer thicknesses of the upper limit of the drying zone to pass gaseous or mist remains dry regions of Thermal decomposition method of biomass.

Images