JP6981645B2 - Biomass semi-carbonization method and its equipment - Google Patents

Description

The present invention relates to a method for semi-carbonizing biomass and an apparatus thereof for obtaining semi-carbonized products using biomass including wood.

What is carbonization? A phenomenon in which when carbon-organic substances such as wood are exposed to high-temperature heat in an environment with little oxygen, the organic substances in the object to be carbonized decompose and the carbon content of individuals with low volatile content is generated as charcoal. Is. Conventionally, in order to leave a large amount of organic matter in the raw material when these operations are performed, it is taken out in a form called semi-carbonization. That is, the technique of torrefaction (semi-carbonization) is to try to keep the energy density as much as possible in the process before carbonization.

The semi-carbonized product is in a state where the heat energy of the organic component remains, and the heat energy that the raw material had in the past is retained compared to the state of complete charcoal in terms of energy, and it is in a state that is useful in terms of calorific value. Become. When used as a biomass fuel, it is useful to keep it semi-carbonized and retain a large amount of heat energy.

By the way, when a carbonization device for fuel purposes is configured, it is a continuous furnace in terms of the amount of processing, and a heat transfer type carbonization device is generally used. In a carbonization furnace, carbonization is promoted by volatilizing organic components by heat transfer and radiation from the heat transfer surface in an environment with little oxygen, and carbonization (carbonization) is obtained. Regarding this carbonization method, the carbonization treatment is performed by heating at a temperature of about 500 ° C. to 700 ° C. as the temperature to be supplied to the external heat.

Further, as a waste drying technique, for example, as shown in Patent Document 1, there is a ventilation type rotary drying device suitable for treating waste. This is a configuration in which a blow pipe for ventilation is inserted axially into a cylinder that is driven to rotate, a large number of branch pipes are branched from the blow pipe, and hot air is blown from the branch pipe to the raw material layer in the cylinder. ing.

Japanese Patent No. 3063163 (Patent WO97 / 38277)

However, when a conventional heat transfer type carbonizing device is used, it is necessary to raise the heat transfer surface temperature to a high temperature in order to efficiently obtain a carbonized product, and the carbonized product has a certain size. In this case, a semi-carbonized product having a high carbonization ratio on the surface of the product and a high organic content in the central portion can be obtained, and it is difficult to obtain the desired carbonized product having a uniform characteristic.

In particular, in the conventional indirect heating type apparatus, it is difficult to obtain the desired semi-carbide having a uniform characteristic because the temperature of the blown hot air changes.

Moreover, for wood biomass, when hot air of 450 ° C or higher is used, carbon organic matter is generally volatilized and powdery soot is generated from the volatile matter. Since this substance is easily ignited in the subsequent process, it is necessary to control it so that it does not form.

By the way, regarding biomass containing wood chips, according to the thermal weight / differential thermal analysis (TG-DTA) device, the temperature at which organic substances undergo carbonization treatment evaporate and decompose is known, and this temperature is effectively used. In order to do so, it is necessary in terms of equipment how to apply this temperature to the carbonized product.

Therefore, the present invention was created in view of the above-mentioned conventional circumstances, and by making it possible to maintain the blowing temperature for the carbonized product and control the treatment time, it is possible to uniformly use biomass including wood. It is an object of the present invention to provide a method for semi-carbonizing biomass and a device thereof capable of obtaining a semi-carbonized product.

In order to solve the above-mentioned problems, in the method for semi-carbonizing biomass according to the present invention, a blowing pipe for blowing hot air is provided in a cylindrical rotary shell that houses and drives the semi-carbonized material. It is inserted in the direction, a large number of branch pipes are branched from the blow pipe, and the oxygen to be burned from the branch pipe to the swinging semi-carbonized material in the rotary shell is within the range of 220 ° C to 430 ° C. It is characterized in that hot air at a predetermined temperature is blown under a negative pressure state.

Further, the rotary shell is provided with double heat-resistant seals on the inlet side and the outlet side of the semi-carbonized material, and nitrogen or steam is filled between the double heat-resistant seals on the inlet side to use nitrogen or steam. It is characterized by forming a reservoir and blocking the ingress of oxygen together with the double heat-resistant seal on the outlet side.

Further, it is characterized in that the combustion exhaust gas is used as a heat source in order to reduce the oxygen concentration in the rotary shell, and steam is generated to heat the hot air blown to the semi-carbonized material to a predetermined temperature.

In addition, as semi-carbonized products, pellet-like, chip-like, and powder-like xylem (rubber tree, palm palm trunk, hardwood, conifer), EFB (residue of palm palm bunch), rice husk, sewage sludge, livestock. It is characterized by using biomass such as sewage.

Further, it is characterized in that 1 to 6 tons of the semi-carbonized product is added per hour to dry for 5 to 15 minutes and semi-carbonized for 15 to 40 minutes.

Further, it is characterized in that 1t to 6t of the material in an absolutely dry state becomes a semi-carbide of 0.5t to 5.4t.

Further, it is characterized in that the input pressure of nitrogen or steam is set to 0.001 MPa to 0.3 MPa.

On the other hand, in the biomass semi-carbonization apparatus according to the present invention, a cylindrical rotary shell that accommodates the semi-carbonized material and drives it to rotate, and an axially inserted blower blowing in the rotary shell. It is equipped with a taco rotary dryer device that includes a pipe and a branch pipe that is branched from a large number of blow pipes, and blows hot air from the branch pipe to the semi-carbonized material in the rotary shell under a negative pressure state. It is characterized by.

Further, the temperature of the hot air from the branch pipe is characterized by being medium-temperature air having a predetermined temperature in the range of 220 ° C. to 430 ° C., which has extremely little oxygen for combustion.

Further, the rotary shell is provided with double heat-resistant seals on the inlet side and the outlet side of the semicarbide, and nitrogen or steam is filled between the double heat-resistant seals on the inlet side to form a reservoir, and the outlet is formed. It is characterized by blocking the ingress of oxygen in combination with the double heat-resistant seal on the side.

Further, the heat-resistant seal is characterized by having a thickness of about 10 mm and a width of 100 mm to 250 mm.

Further, it is characterized by being provided with a heat source mechanism for introducing a superheated steam mixed gas that enables ignition prevention of the semi-carbonized material and reduction of oxygen concentration in the rotary shell into the blow pipe.

According to the present invention, by adopting a heating means by an octopus rotary dryer method (ventilation type rotary dryer) as a semi-carbonization device, a uniform semi-carbonized product using biomass can be easily obtained.

In particular, the rotary shell is provided with a double heat-resistant seal portion on the inlet side and the outlet side of the semi-carbonized material, and nitrogen or steam is filled between the double heat-resistant seals on the inlet side to form a reservoir. However, since oxygen is prevented from entering the rotary shell together with the double heat-resistant seal on the outlet side, it is possible to prevent a fire or an explosion during the semi-carbonization operation.

It is a block diagram of the processing flow which shows one embodiment for carrying out this invention. It is a vertical sectional view of the ventilation type rotary dryer used as the semi-carbonization apparatus of this invention. It is also a side view which shows the appearance of the ventilation type rotary dryer. It is an enlarged sectional view which shows the arrangement example of the double heat-resistant seal part provided on the entrance side. It is also a plan view which shows the appearance of the ventilation type rotary dryer. It is also the front view which shows the appearance of the ventilation type rotary dryer. It is a rear view which also shows the appearance of the ventilation type rotary dryer. It is a figure which shows the measurement result of the wood chip by the thermogravimetric analysis and the differential thermal analysis. It is a figure which shows the measurement result in the form of powder by the thermogravimetric analysis and the differential thermal analysis. It is a figure which shows the immersion test measurement table of the wood pellet (rubber tree). It is a figure which shows the immersion test measurement table of EFB (empty fruit bunch which is a residue of palm palm bunch). In FIG. 12, (a) to (g) are explanatory views including a drawing substitute photograph of a wood pellet (rubber tree). In FIG. 13, (a) to (h) are explanatory views including a drawing substitute photograph of a immersion test of a wood pellet (rubber tree). In FIG. 14, (a) to (e) are explanatory views including a drawing substitute photograph of a wood pellet (rubber tree). In FIG. 15, (a) to (h) are explanatory views including a drawing substitute photograph of an immersion test of EFB (empty fruit bunch which is a residue of palm palm bunch). In FIG. 16, (a) to (f) are explanatory views including a drawing substitute photograph of water repellency of a wood pellet (rubber tree).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a semi-carbonization device as a torrefaction (semi-carbonization) technique in the present invention. For example, as the semi-carbonization device, the ventilation type rotary dryer P (TACO dryer) used in the above-mentioned Patent Document 1 (Patent No. 3063163 (Patent WO 97/38277)) is used. As will be described later, the ventilation type rotary dryer P has a cylindrical rotary shell 1 that accommodates and drives the semi-carbonized material W and a blower for blowing air that is inserted in the rotary shell 1 in the axial direction. The blown pipe is provided with a pipe 4 and a branch pipe 4A branched from the blown pipe 4 in large numbers, and hot air by superheated steam that enables ignition prevention of the semi-carbonized material W and reduction of the oxygen concentration in the rotary shell 1 is provided. It is provided with a heat source mechanism Q for introduction to 4. As a result, hot air is blown from the branch pipe 4A to the semi-carbonized product W in the rotary shell 1 under a negative pressure state. In this device, the semi-carbonized material W, which will be described later, can be blown at the same blowing temperature.

Further, in order to configure this device as a semi-carbonization device, for example, combustion gas from the heat source mechanism Q is used in order to reduce the oxygen concentration in the rotary shell 1. Further, the heat source mechanism Q described above is a mechanism for generating steam to heat the blown air to a predetermined temperature. Alternatively, in the heat source mechanism Q, biomass can be burned to produce sprayed gas.

It should be noted that there is a risk of ignition unless the produced semi-carbonized product is taken out to an environment with oxygen after the temperature is lowered to 220 ° C. or lower. Therefore, a cooling mechanism (not shown) is provided inside the apparatus or outside in a deoxidized environment.

The specific configuration of this device will be described below. As shown in FIG. 1, a rotatable cylindrical rotary shell 1 in which the semi-carbonized material W is charged from a raw material inlet and the semi-carbonized material W is introduced by a charging feeder, and inside the rotary shell 1. In the exhaust gas from the rotary shell 1, for example, the heat source mechanism Q for pumping superheated steam (hot air) having a temperature of 220 to 430 ° C., the combustion fan F3 for introducing outside air into the heat source mechanism Q, and the exhaust gas from the rotary shell 1. From the dust collector R, for example, a cyclone type, for collecting dust and returning a part to the heat source mechanism Q by the exhaust fan F1 and exhausting the other part to the outside of the device. It is mostly composed. The heat source mechanism Q has a structure in which exhaust gas from some existing factories can be used for heavy oil, kerosene, gas, steam, electricity, and other energy saving.

In this device, combustion exhaust gas is used as a heat source in order to reduce the oxygen concentration in the rotary shell 1, and further, steam is generated and the air blown to the semi-carbonized material W is blown to a predetermined temperature (220 ° C. with less oxygen). It is configured to be heated to ~ 430 ° C., and the semi-carbonized product W is a wood chip (rubber tree) such as pellets, chips, or powder, or EFB (residue of palm palm bunch). A certain empty fruit bunch) etc. are used.

As shown in FIG. 2, the rotary shell 1 is formed in a substantially hollow cylindrical shape in which the ratio of length to width is set to, for example, 3: 1. It is drawn in a direction parallel to the rotation axis of the rotary shell 1, and a plurality of branch pipes 4A are directed toward the inner wall of the rotary shell 1 and alternately inclined along the rotation axis on the peripheral surface of the blow pipe 4. They are installed in order at regular intervals. The semi-carbonized material W is housed in the rotary shell 1 so as to be swingable or rollable with a volume ratio of about 10 to 15% with respect to the total volume.

Then, at the same time as the semi-carbonized material W swings or rolls with the rotation of the rotary shell 1 itself, the superheated steam of the heat source mechanism Q is introduced from the superheated steam mixed gas inlet of the blow pipe 4, and the superheated steam of the heat source mechanism Q is introduced in the rotary shell 1. The superheated steam is blown out from the branch pipe 4A as hot air so that the internal semi-carbonized product W can be carbonized in a low oxygen (negative pressure) state. In this case, the hot air temperature is set to medium temperature air having a predetermined temperature in the range of 220 ° C. to 430 ° C. in which the amount of oxygen to be burned is extremely small in order to be semi-carbonized.

As shown in FIGS. 3 to 7, in the ventilation type rotary dryer P, both ends of the rotary shell 1 are airtightly and rotatably fitted to the end plate 8 and the end box 9. The end plate 8 and the end box 9 are mounted on the common mount 5. A dryer charging conveyor 13 is attached to the end plate 8, and an discharge port 14 and an exhaust port 15 for discharging the processed raw material are provided in the end box 9. The exhaust port 15 is connected to the dust collector R described above. In the figure, reference numeral 12 is a heat-resistant seal portion arranged at both ends of the rotary shell 1.

Further, as shown in FIGS. 4A and 4B, the rotary shell 1 has a disk shape, for example, a thickness of about 10 mm and a width along the shell shape on the inlet side of the semi-carbonized material W. A double heat-resistant seal portion 12 (mesh-shaped in the figure) of 100 mm to 250 mm or the like is provided, and nitrogen or steam is filled between them to form a reservoir. Similarly, double heat-resistant seals are provided on the outlet side to prevent oxygen from entering the rotary shell 1.

A sprocket 3 and two tires 2 are externally fitted on the outer peripheral surface of the rotary shell 1, and the sprocket 3 engages with a speed reducer 7 of a rotary drive device mounted on a common gantry 5. The two tires 2 ride on the tire receiving rollers 6 placed on the common gantry 5. The tire receiving roller 6 supports the rotary shell 1 and rotates the rotary shell 1 at a predetermined speed via the speed reducer 7.

The blow pipe 4 extending from the heat source mechanism Q is passed through the back surface of the end box 9. The blow pipe 4 penetrates the rotary shell 1 in the axial direction and reaches the end plate 8 side. An inspection port 11 is provided on the end plate 8 on the front side of the rotary shell 1, and a manhole 10 is provided on the end box 9 on the back side of the rotary shell 1.

Was charged 1t~6t per hour to be semi-carbonized treated W rotary shell 1 volume ^{20m 3 ~100m} 3, dried 5 minutes to 15 minutes, and half carbide 15 minutes to 40 minutes. In this case, 1t to 6t of the material in an absolutely dry state becomes a semi-carbide of 0.5t to 5.4t. The nitrogen input pressure (filling pressure) into the rotary shell 1 is 0.001 MPa to 0.3 MPa.

For biomass containing wood chips, the temperature at which organic matter evaporates and decomposes during carbonization is known according to the thermogravimetric analysis (TG-DTA) device, and this temperature can be used effectively. Therefore, how to apply this temperature to the carbonized product is required for this device.

FIG. 8 is a diagram showing the measurement results of wood chips by thermal weight / differential thermal analysis when the carrier gas is nitrogen (anoxic). According to this figure, the weight loss is −75.88 Weight /% from the TG curve in the carbonized center (carbonized region) at 261 ° C to 358 ° C, and almost no heat generation / endothermic peak is observed from the DTA curve.

FIG. 9 shows the solid content and fine powdery decomposition products obtained when the evaporation of wood organic content by thermal weight / differential thermal analysis when the carrier gas is air is heated at about 450 ° C. or higher in a deoxidized environment. It is a figure which shows the measurement result. According to this figure, the exothermic reaction started slowly from around 220 ° C. from the DTA curve, and the exothermic peak was obtained at the combustion temperature of 507.4 ° C.

As described above, in the present embodiment, unlike the heat transfer type carbonizing device described above, medium-temperature air at a predetermined temperature from 220 ° C. to 430 ° C., which burns extremely little oxygen, is blown onto the semi-carbonized product W at high speed. It is carbonized. At this time, by changing the blowing temperature and the treatment time, it is possible to select the volatile component, and it is possible to control the properties of the semi-carbonized product produced. For example, it is possible to leave a resin or the like generated from wood on the surface of the wood pellet to have water repellency or the like.

FIG. 10 is a diagram showing an immersion test measurement table of wood pellets (rubber tree), and FIG. 11 is a diagram showing an immersion test measurement table of EFB (empty fruit bunch which is a residue of palm palm bunch). .. According to this figure, when both are semi-carbonized, the change in water content before and after immersion is very large. In addition, FIG. 10 and FIG. 11 show the water repellency data of the raw material and the semi-carbonized product, and are a table showing the aggregation of various numerical values of the dipping treatment conditions and mass measurement when the carbonization degrees of the wood chips and the EFB are different. Is. In the case of unprocessed rubber wood pellets, the pellets collapse when wet with water, but when semi-carbonized, the pellets do not collapse. These detailed explanations will be omitted with reference to the description in each figure.

FIG. 12 is an explanatory view including a drawing substitute photograph of the wood pellet (rubber tree), FIG. 13 is an explanatory view including a drawing substitute photograph of the immersion test of the wood pellet (rubber tree), and FIG. 14 is an explanatory view of the wood pellet (rubber tree). An explanatory view including a drawing substitute photograph of a rubber tree), FIG. 15 is an explanatory view including a drawing substitute photograph of an EFB (empty fruit bunch which is a residue of palm palm bunch), and FIG. 16 is a wood pellet (a wood pellet). It is explanatory drawing including the drawing substitute photograph of the water repellency of a rubber tree). These detailed explanations will be omitted with reference to the description in each figure.

W Semi-carbonized material P Ventilation type rotary dryer Q Heat source mechanism R Dust collector F1 Exhaust fan F2 Blow-in fan F3 Combustion fan 1 Rotary shell 2 Tire 3 Sprocket 4 Blow-in pipe 4A Branch pipe 5 Common mount 6 Roller 7 Reducer 8 End box 9 End box 10 Manhole 11 Inspection port 12 Heat-resistant seal part 13 Dryer input conveyor 14 Discharge port 15 Exhaust port

Claims (9)

A blowing pipe for hot air blowing is axially inserted into a cylindrical rotary shell that accommodates the semi-carbonized material and is driven to rotate, a large number of branch pipes are branched from the blowing pipe, and the rotary is used from the branch pipe. the swings in the shell to be semi-carbonized product, shall blowing hot air of a predetermined temperature in the oxygen is extremely small 220 ° C. to 430 ° C. range for combustion under a negative pressure state,
The rotary shell is provided with double heat-resistant seals on the inlet side and the outlet side of the semi-carbonized material, and nitrogen or steam is filled between the double heat-resistant seals on the inlet side to store nitrogen or steam. A method for semi-carbonizing biomass , which comprises forming the above and preventing the infiltration of oxygen together with the double heat-resistant seal on the outlet side. The first aspect of claim 1, wherein the combustion exhaust gas is used as a heat source in order to reduce the oxygen concentration in the rotary shell, and steam is generated to heat the hot air blown to the semi-carbonized material to a predetermined temperature. Semi-carbonization method of biomass. Pellet-like, chip-like, powdery xylem (rubber tree, palm palm trunk, hardwood, coniferous tree), EFB (residue of palm palm bunch), rice husk, sewage sludge, livestock manure as semi-carbonized material The method for semi-carbonizing the biomass according to claim 1 or 2 , wherein the biomass such as the above is used. The biomass according to any one of claims 1 to 3 , wherein the semi-carbonized product is charged with 1 to 6 tons per hour and dried for 5 to 15 minutes and semi-carbonized for 15 to 40 minutes. Semi-carbonization method. The method for semi-carbonizing biomass according to claim 4 , wherein the material 1t to 6t in an absolutely dry state becomes a semi-carbide of 0.5t to 5.4t. The method for semi-carbonizing biomass according to any one of 1 to 5, wherein the input pressure of nitrogen or steam is 0.001 MPa to 0.3 MPa. A rotary shell cylindrical driven rotating housing to be semi-carbonized product, and the blow pipe for the inserted feed air blowing write in the axial direction of the rotary shell, and a branch pipe which number is branched from the blowing tubes provided, comprising a kite rotary dryer apparatus comprising as blowing hot air to the object to be semi-carbonized product in the rotary shell from the branch pipe under a negative pressure state,
The hot air temperature from the branch pipe is medium-temperature air having a predetermined temperature in the range of 220 ° C. to 430 ° C., which has extremely little oxygen for combustion.
The rotary shell is provided with double heat-resistant seals on the inlet side and the outlet side of the semi-carbonized material, and nitrogen or steam is filled between the double heat-resistant seals on the inlet side to form a reservoir, and the outlet is formed. A semi-carbonization device for biomass characterized by blocking the ingress of oxygen in combination with a double heat-resistant seal on the side. The semi-carbonized device for biomass according to claim 7 , wherein the heat-resistant seal has a thickness of about 10 mm and a width of 100 mm to 250 mm. 7. The described biomass semi-carbonization device.

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