JP4741686B2 - Gasification method, power generation method, gasification device, power generation device, wood chip, and liquid phase light oil that can be used as an energy source and water in which water-soluble organic substances are dissolved - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can be utilized as a gasification method for gasifying organic substances, a power generation method for generating power using gas gasified by the gasification method, a gasification device, a power generation device, a wood chip, and an energy source. It relates to water in which liquid light oil and water-soluble organic substances are dissolved .

  Biomass is attracting attention as an energy source with a small environmental load. Biomass is a biological resource excluding fossil resources, for example, organic matter such as wood, paper, agricultural residues, manure, and food waste. The energy obtained from biomass is one of so-called renewable energy and is called biomass mass energy. Renewable energy means that the amount of carbon dioxide absorbed by a living organism and the amount of carbon dioxide emitted when biomass derived from that organism is burned are offset by the same amount on a global scale. This means that the current atmospheric carbon dioxide concentration does not increase even if is used.

Biomass energy is used, for example, using a gasification power generation device. The gasification power generation apparatus generates flammable gas by pyrolyzing biomass at a high temperature of 600 ° C. or higher, and generates electricity using the gas as fuel.
However, in the gasification of biomass, tar is generated together with combustible gases such as carbon monoxide, methane, and ethane, and carbonaceous solids. Tar generated in gasification is vaporized during pyrolysis, but when it is sent to the power generation device and the temperature drops, it adheres to the pipes that make up the power generation device, and the power generation device malfunctions or fails. Invite

  As a method for removing tar from a tar-containing gas, a method is proposed in which the tar-containing gas is brought into contact with a porous inorganic material, thereby supporting the tar as a solid carbonaceous material on a porous inorganic material, such as aluminum oxide (for example, Patent Document 1). A porous inorganic material carrying a carbonaceous material is excellent in storage and transportability, and energy can be taken out as tar-free hydrogen gas by contacting with water vapor. Moreover, the porous inorganic substance after generating hydrogen gas can be reused for tar removal.

JP 2008-095175 A

  However, in the method according to Patent Document 1 in which tar is recovered as a solid carbonaceous material, it is necessary to prepare a porous inorganic material corresponding to the amount of tar generated. Needless to say, Patent Document 1 does not disclose a technical idea of removing tar from a tar-containing gas without using a porous inorganic substance.

  The present invention has been made in view of such circumstances, and by adsorbing tars contained in a gas containing organic matter, for example, tar generated by pyrolysis of a wood chip, to the organic matter before pyrolysis, the tars are formed into carbon. A gasification method capable of generating a tar-free gas without preparing a porous inorganic material to be decomposed and supported on a solid, and using or recovering the tar as an energy source, It aims at providing the electric power generation method which performs electric power generation, the gasifier which implements each method, and an electric power generating apparatus.

  Another object of the present invention is to thermally decompose organic matter adsorbed with tar as a fuel, thereby co-carbonizing the organic matter and tar adsorbed on the organic matter, and recovering the tar as a carbonaceous solid and a tar-free gas. An object of the present invention is to provide a gasification method, a power generation method, a gasification device, and a power generation device that can be used.

  Another object of the present invention is to adsorb tar to the organic matter while preventing the organic matter from burning by the tar-containing gas generated by thermal decomposition by adsorbing the tar to the organic matter while stirring the organic matter. A gasification method, a power generation method, a gasification device, and a power generation device are provided.

Another object of the present invention is to provide a wood chip having a high thermal decomposition efficiency and a high energy density as compared with an organic substance not in contact with a tar-containing gas.

The gasification method according to the present invention is a gasification method for gasifying crushed or granular wood chips. By heating the wood chips to 400 to 600 ° C., the wood chips are converted into a tar-containing gas and a carbonaceous solid. The pyrolysis step for pyrolysis and the tar-containing gas generated by pyrolysis are brought into contact with stirring before the tar contained in the tar-containing gas is liquefied before being crushed or granular wooden chips. An adsorption step for adsorbing the tar contained in the tar-containing gas to the wood chip, wherein the thermal decomposition step thermally decomposes the wood chip obtained by adsorbing the tar in the adsorption step, By cooling the tar-free gas obtained by bringing the tar-containing gas generated by the thermal decomposition of the wooden chips adsorbed with the tar into the wooden chips before the thermal decomposition, The Lumpur-free gas, and non-condensable gases flammable, is separated into the water a light oil and water-soluble organic substances capable of utilizing liquid phase was dissolved as an energy source, separated in the liquid phase It has the process of collect | recovering a substance , It is characterized by the above-mentioned.

Power generation method according to the present invention is characterized in that for generating electric power by burning the tar-free gas generated by the above-mentioned gasification process.

The gasification apparatus according to the present invention is a gasification apparatus for gasifying crushed or granular wood chips. By heating the wood chips to 400 to 600 ° C., the wood chips are converted into a tar-containing gas and a carbonaceous solid. The thermal decomposition means for thermal decomposition and the tar-containing gas generated by the thermal decomposition are brought into contact with the crushed or granular wood chips before thermal decomposition with stirring before the tar contained in the tar-containing gas is liquefied. The adsorption means for adsorbing the tar contained in the tar-containing gas to the wood chip, the collection means for collecting the wood chip on which the tar is adsorbed by the adsorption means, and the wood chip collected by the collection means Obtained by bringing the tar containing gas generated by the pyrolysis of the wood chip that has been adsorbed to the pyrolysis means and the wood chip to which the tar is adsorbed into contact with the wood chip before pyrolysis By cooling the tar-free gas, the tar-free gas, and a non-condensable gas combustible, the water a light oil and water-soluble organic substances capable of utilizing liquid phase was dissolved as an energy source And a means for recovering the separated water in the liquid phase .

Gasifier according to the present invention, the thermal decomposition section, a hollow cylindrical shape, has a wood chip supply port wood chips are fed into one end, coal-like for discharging Sumijo solid at the other end A thermal decomposition reactor having a solid discharge port and an exhaust port for exhausting tar-containing gas; and a conveying screw for conveying the wood chip supplied to the pyrolysis reactor from the one end side to the other end side, and the adsorption means is connected by a pipe to the pyrolysis reactor, the inlet of tar-containing gas flows, and a hollow cylindrical tar-free gas has an outlet for outflow, the wood chips prior to pyrolysis It is provided with the container to accommodate, and the stirring blade which stirs the wooden chip accommodated in this container.

  A power generation device according to the present invention includes any one of the above-described gasifiers, an engine that outputs power by burning a tar-free gas gasified by the gasifier, and the power of the engine And a generator for generating electricity.

The wood chip according to the present invention is characterized in that tar is adsorbed using any one of the gasification methods described above or any one of the gasification devices described above.
The liquid phase light oil that can be utilized as an energy source according to the present invention and water in which the water-soluble organic substance is dissolved are water-soluble organic substances as a main component, and any one of the gasification methods described above, or the above-mentioned It isolate | separates using any one gasifier, It is characterized by the above-mentioned.

  According to the present invention, first, an organic substance is heated, and the organic substance is thermally decomposed into a tar-containing gas and a carbonaceous solid. Then, the tar-containing gas generated by pyrolysis is brought into contact with the organic matter before pyrolysis. When the tar-containing gas comes into contact with an organic substance, the tar-containing gas is reformed to a tar-free gas because the tar contained in the tar-containing gas is adsorbed by the organic substance. Therefore, tar can be removed from the tar-containing gas without preparing a porous inorganic substance and performing an operation such as catalyst reforming.

In addition , the organic matter adsorbed with tar is thermally decomposed. When organic matter that adsorbs tar is thermally decomposed, compared with the case where tar and organic matter are heated as a simple substance, the carbonization effect of tar and organic matter is mutually promoted, and the evaporation of tar adsorbed on organic matter is suppressed. The effect promotes the decomposition of tar. That is, a part of the tar adsorbed on the organic matter is not vaporized and becomes a carbonaceous solid together with the organic matter. Further, a part of the tar is decomposed into a tar-free gas without being vaporized.
Therefore, the tar adsorbed on the organic matter can be recovered as a carbonaceous solid or a tar-free gas. In other words, it is possible to remove tar from the tar-containing gas without preparing a porous inorganic material and performing operations such as catalyst reforming, and it is possible to increase production of carbonaceous solids and tar-free gas. .
Further, a substance having a boiling point less than a predetermined temperature contained in the tar-free gas is condensed and recovered. This substance contains liquid light oil, water-soluble organic matter, etc., and can be used as an energy source.

  According to the present invention, the tar contained in the tar-containing gas is adsorbed on the organic matter while stirring the crushed or granular organic matter. Therefore, it is possible to prevent the organic matter from being burned by the tar-containing gas after pyrolysis.

  According to the present invention, a tar-free gas can be generated using a wood chip, wood flour, agricultural waste, or a biofuel squeezer. Agricultural waste is, for example, sugar cane bagasse, rice straw, wheat straw, rice husk and the like.

  According to the present invention, power generation can be performed by burning the tar-free gas generated by the gasification method described above.

According to the present invention, the organic substance obtained by bringing the tar-containing gas into contact has the energy of the adsorbed tar in addition to the energy of the organic substance itself. Further, when the tar-containing gas generated by the thermal decomposition is brought into contact with an organic substance, the moisture contained in the organic substance is evaporated by the heat of the tar-containing gas.
Accordingly, the energy per unit weight of the organic substance is higher than that of the organic substance not in contact with the tar-containing gas.
In addition, when the organic matter is thermally decomposed, energy for evaporating moisture contained in the organic matter is not required, so that energy required for the thermal decomposition can be reduced.

  According to the present invention, it is possible to generate a tar-free gas without preparing a porous inorganic substance that decomposes and supports tar into a carbonaceous solid, and can use or recover the tar as an energy source.

  According to the present invention, an organic substance and tar adsorbed on the organic substance can be co-carbonized, and the tar can be recovered as a carbonaceous solid and a tar-free gas.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that organic substance burns with the tar containing gas generate | occur | produced by thermal decomposition, and tar can be made to adsorb | suck to organic substance effectively.

According to the present invention, the thermal decomposition efficiency and energy density of the wood chip can be improved as compared with an organic substance not in contact with a tar-containing gas.

It is explanatory drawing which shows notionally the gasification method which concerns on Embodiment 1 of this invention. It is typical sectional drawing which shows the structural example of the gasification apparatus of this invention. It is a schematic diagram which shows the structure of the gasification apparatus which concerns on the modification 1. FIG. 6 is a schematic diagram illustrating a configuration of a power generation device according to a second embodiment. It is explanatory drawing which shows notionally the gasification method which concerns on Embodiment 3. FIG. FIG. 6 is a schematic cross-sectional view showing a configuration example of a gasifier according to Embodiment 3. It is explanatory drawing which shows notionally the gasification method which concerns on Embodiment 4. FIG. 6 is a schematic diagram showing a configuration of a gasifier according to Embodiment 4. FIG. It is explanatory drawing which shows the effect of the gasification method which concerns on Embodiment 4. FIG. It is explanatory drawing which shows notionally the experimental method for confirming the effect of the gasification method which concerns on this invention. It is a graph which shows the change of the tar yield accompanying the increase in a tar recycle operation number. It is a graph which shows the change of the yield of charcoal, water, and a light organic component accompanying a tar recycling operation number. It is a graph which shows the change of the noncondensable gas yield accompanying the increase in a tar recycle operation number. It is a graph which shows the change of the tar conversion rate accompanying the increase in a tar recycle operation number.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
(Embodiment 1)
FIG. 1 is an explanatory diagram conceptually showing a gasification method according to Embodiment 1 of the present invention. In the gasification method according to Embodiment 1 of the present invention, a porous inorganic substance is obtained by adsorbing tar contained in a tar-containing gas generated by thermal decomposition of a wooden chip (organic substance) to the wooden chip before thermal decomposition. A tar-free gas can be generated without preparing and performing operations such as catalyst reforming.

In the gasification method according to the present invention, first, as shown by the brackets and broken line arrows in FIG. 1, a wooden chip that does not adsorb tar (hereinafter referred to as tar unadsorbed wooden chip) is 400 to 600 ° C., for example, Heated at 500 ° C., the tar non-adsorbed wood chips are pyrolyzed into charcoal and tar-containing gas. In order to obtain tar-free charcoal, it is preferable to heat the tar non-adsorbed wood chips at 500 ° C. or more with a residence time of 0.5 to 20 minutes. Tar-free charcoal refers to charcoal with an aromatic generation amount of less than 0.01 wt% when heated to 600 ° C or higher. If only the carbonization is performed, it is sufficient to heat the tar non-adsorbed wood chips to 400 ° C. or higher, but in order to obtain tar-free charcoal, it is necessary to heat the tar non-adsorbed wood chips at 500 ° C. or higher. is there.
And the charcoal produced | generated by thermal decomposition is collect | recovered. In the initial stage of the gasification method, there is no wood chip that has adsorbed tar (hereinafter referred to as a tar-adsorbed wood chip), so the operation is started by thermally decomposing the tar non-adsorbed wood chip. In the following description, the term wood chip is used as a general term for tar non-adsorbed wooden chips and tar-adsorbed wooden chips.

The tar-containing gas includes a flammable non-condensable gas containing hydrogen, carbon monoxide, carbon dioxide, lower hydrocarbon gas, etc., a light organic component having a condensability and a boiling point of less than 350 ° C., and a light Contains tar gas having a boiling point higher than that of organic components and water vapor. The light organic component includes light oil and water-soluble organic matter.
Tar gas becomes a black or black-brown liquid or solid when cooled to room temperature, and is a condensable compound having a boiling point of 350 ° C. or higher, that is, tar is vaporized. Here, the condensability means the property of becoming a liquid or a solid at normal temperature and normal pressure.
The tar-containing gas is in a state in which tar vapor is contained in the non-condensable gas in an uncooled state immediately after thermal decomposition.

  Next, while stirring the tar non-adsorbed wood chip prepared separately from the above-mentioned tar non-adsorbed wood chip for thermal decomposition, by contacting the tar-containing gas generated by pyrolysis with the tar non-adsorbed wood chip, The tar contained in the tar-containing gas is adsorbed on the non-tar-adsorbed wood chip. Tar-free gas is obtained by adsorption of tar. The tar-free gas is a gas obtained by removing a tar component from a tar-containing gas, and includes a non-condensable gas, a light organic component, and water vapor.

Experiments have confirmed that untarred wood chips can hold at least about 67 wt% tar of dry weight. The experimental method is as follows. First, tar generated when a tar non-adsorbed wood chip is thermally decomposed at 500 ° C. is once dissolved in a solvent such as acetone. Then, after immersing the wooden chips in the tar solution, the solvent is evaporated to prepare the already adsorbed wooden chips. By comparing the mass of the wood chip before and after tar adsorption, the tar-adsorbed wood chip obtained as a result of the adjustment is composed of a weight 1 tar unadsorbed wood chip (dried) and a weight 0.67 tar. Can be confirmed.
The tar-adsorbed wooden chips can be handled, pyrolyzed and gasified in the same manner as the tar-unadsorbed wooden chips without agglomeration.

Moreover, the tar non-adsorbed wood chips are dried simultaneously by bringing the tar-containing gas chips into contact with the tar non-adsorbed wood chips. In order to dry the tar unadsorbed wood chips and prevent the water vapor and light organic components from condensing, it is necessary to bring the tar-containing gas into contact with the tar unadsorbed wood chips at a temperature of 110 ° C. or higher, for example.
In addition, since the tar-containing gas does not contain oxygen, problems such as ignition may occur if the temperature does not exceed 350 ° C, where thermal decomposition of the unadsorbed wood chips becomes active, even if a portion of 200 ° C or higher occurs. There is no. Further, since the tar non-adsorbed wood chip contains moisture, even if a tar-containing gas exceeding 500 ° C. is brought into contact with the tar non-adsorbed wood chip, the temperature of the tar non-adsorbed wood chip immediately exceeds 350 ° C. There is nothing. Therefore, even if a tar-containing gas of about 500 ° C. is supplied to the tar non-adsorbed wood chip, there is no problem such as ignition as long as the tar non-adsorbed wood chip is stirred.

  In some cases, the tar may be adsorbed using a pre-dried tar non-adsorbed wood chip. By cooling the tar-free gas, the tar-free gas can be separated into a non-condensable gas, a light organic component and water, but water-soluble organic substances contained in the light organic component are dissolved in water. Therefore, when it is desired to co-produce a mixture of a high-quality light organic component and water, it is better that less water vapor is contained in the non-tar-containing gas.

  According to such a gasification method according to the first embodiment, without preparing a porous inorganic material and performing an operation such as catalyst reforming, from a tar-containing gas generated by thermal decomposition of a tar unadsorbed wooden chip. Tar can be removed, and charcoal, tar-free gas, and tar-adsorbed wood chips can be co-produced and recovered.

  Next, the tar-adsorbed wood chips obtained by tar adsorption are collected. After collecting the tar-adsorbed wooden chips, as shown in FIG. 1, a thermal decomposition process is performed using the collected tar-adsorbed wooden chips. That is, the tar-adsorbed wooden chip is heated at 500 ° C., and the tar-adsorbed wooden chip is pyrolyzed into charcoal and a tar-containing gas.

By the way, when the tar-adsorbed wood chips are pyrolyzed, not all of the tar adsorbed on the tar-unadsorbed wood chips evaporates as tar vapor, and some of the wood chips are due to the co-carbonization effect and the tar evaporation suppression effect. It carbonizes with the part or decomposes into light organic components. The co-carbonization effect refers to an effect that the carbonization of the tar and the wood chip portion is mutually promoted as compared with the case where the tar and the tar non-adsorbed wood chip are heated in a simple manner. In addition, the evaporation suppression effect is that the tar component in the already-adsorbed wooden chip is physically confined, or the tar component molecule is bonded to the wooden chip molecule to adsorb to the already-adsorbed wooden chip. This means the effect of suppressing the evaporation of tar.
Thus, the tar component contained in the tar-containing gas can be finally recovered as charcoal and light organic components by co-carbonization of the tar-adsorbed wood chips.

  Thereafter, by repeating the generation, recovery, and thermal decomposition of the tar-adsorbed wood chips, it is possible to generate a tar-free gas without preparing a porous inorganic material that decomposes and supports the tar into a carbonaceous solid. In addition, charcoal and tar-free gas can be increased.

Next, the gasification apparatus 1 for implementing the gasification method which concerns on this invention is demonstrated.
FIG. 2 is a schematic cross-sectional view showing a configuration example of the gasifier 1 of the present invention. The gasifier 1 includes a pyrolysis device (pyrolysis means) 2 that thermally decomposes wood chips into combustible tar-containing gas and charcoal, and adsorbs tar in the tar-containing gas onto the tar non-adsorbed wood chips. And a tar adsorbing device (adsorbing means) 3 for reforming to a tar-free gas and simultaneously producing the already adsorbed wooden chips.

  The thermal decomposition apparatus 2 includes a hollow cylindrical thermal decomposition reactor 21. The pyrolysis reactor 21 is installed in a substantially horizontal posture in an electric furnace 22 that heats the pyrolysis reactor 21 to 400 to 600 ° C. The heating means of the pyrolysis reactor 21 is not limited to the electric furnace 22. For example, the pyrolysis reactor 21 may be arranged inside a combustion heating furnace of an external hot air heating tank type so that the pyrolysis reactor 21 is heated. A hopper 24 for supplying a wood chip into the pipe is coupled to a wood chip supply port (organic material supply port) 21 a provided at one end of the pyrolysis reactor 21. 24 and a conveying screw 23 for conveying the wooden chip supplied from the wooden chip supply port 21a to the other end side. The pyrolysis reactor 21 has a charcoal discharge port (charcoal solid discharge port) 21b and an exhaust port 21c at the other end. The exhaust port 21c is connected to a pipe 25 that guides the tar-containing gas generated by the thermal decomposition of the wood chips to the tar adsorption device 3, and the charcoal discharge port 21b is provided with a charcoal recovery unit 26 that recovers charcoal as a residue. It has been.

  The tar adsorption device 3 includes a vertically long bottomed cylindrical wood chip stirring tank (housing body) 31 and a rear wooden chip stirring tank (housing body) 32 each containing an appropriate amount of unadsorbed wood chips, and each stirring tank. And a connecting pipe 33 to be connected.

  The front-stage wood chip agitation tank 31 has a vertically long bottomed cylindrical shape having an inner diameter of 60 mm and a height of 270 mm, and has a gas inlet 31 a having a diameter of 0.5 inch on the upper end side portion. A pipe 25 communicating with the reactor 21 is connected. Moreover, the front | former stage wood chip | tip stirring tank 31 has the connection port 31b in the lower end side part, and the end of the connection pipe | tube 33 is connected to the connection port 31b. The connection port 31b functions as a gas outlet in the upstream wood chip stirring tank 31. Further, the front-stage wood chip agitation tank 31 includes an agitation mechanism for agitating the accommodated tar unadsorbed wood chips. The stirring mechanism has a stirring shaft that is rotatably arranged on the central axis of the preceding-stage wood chip stirring tank 31. On the stirring shaft, a plurality of stirring blades 31c are formed in a spiral shape along the stirring shaft. The stirring blade 31c has a rectangular shape of 5 mm square and a thickness of 2 mm. The stirring speed is a maximum of 60 revolutions / minute. The stirring blade 31c corresponds to a means for stirring the organic matter. Further, the pre-stage wood chip agitation tank 31 includes an opening / closing section (not shown), and is configured so that the unadsorbed wood chips and the recovered adsorbed wood chips can be collected.

  The post-stage wood chip stirring tank 32 has the same configuration as the front-stage wood chip stirring tank 31. The post-stage wood chip agitation tank 32 has a connecting port 32b at the lower end side, and the other end of a connecting tube 33 having a diameter of 0.5 inch is connected to the connecting port 32b. The connection port 32b functions as a gas inlet in the post-stage wood chip stirring tank 32. Further, the post-stage wood chip agitation tank 32 includes an agitation mechanism for agitating the accommodated tar unadsorbed wood chips, and is configured to agitate the tar unadsorbed wood chips by a plurality of agitation blades 32c. Further, the post-stage wood chip agitation tank 32 has a gas outlet 32 a having a diameter of 0.5 inch on the upper end side, and the tar-containing gas generated by the thermal decomposition of the wood chips is sent to the front-stage wood chip agitation tank 31. It is configured to flow into the tar unadsorbed wood chips in the front wood chip agitation tank 31, the connecting pipe 33 and the rear wood chip agitation tank 32.

The usage method of the gasifier 1 is demonstrated. First, the tar non-adsorbed wood chip is put into the hopper 24 and the electric furnace 22 and the conveying screw 23 are driven. The heating temperature of the pyrolysis reactor 21 by the electric furnace 22 is 500 ° C., and the conveying speed of the tar non-adsorbed wooden chips by the conveying screw 23 is such that the residence time of the tar non-adsorbed wooden chips in the pyrolysis reactor 21 is 0.5-20. Set to minutes. Then, the tar unadsorbed wood chips are put into the front wood chip stirring tank 31 and the rear wood chip stirring tank 32, and the stirring mechanism is operated.
Next, when a predetermined amount of the tar-adsorbed wooden chip is thermally decomposed to generate the tar-adsorbed wooden chip, the tar-adsorbed wooden chip is collected and put into the hopper 24. And the thermal decomposition apparatus 2 and the tar adsorption | suction apparatus 3 are driven like a tar non-adsorption | sucking wood chip | tip. Thereafter, the generation, recovery, and thermal decomposition of tar-adsorbed wood chips are repeated.

  In the gasification method and gasification apparatus 1 according to Embodiment 1, tar-free gas can be generated without preparing a porous inorganic material that decomposes and supports tar into a carbonaceous solid.

  Further, the tar adsorbed on the already adsorbed wood chips can be co-carbonized, and the tar can be increased and recovered as charcoal and tar-free gas.

  Furthermore, since the tar-containing gas and the tar non-adsorbed wooden chip are brought into contact with each other while the tar non-adsorbed wooden chip is stirred, the tar is adsorbed on the tar non-adsorbed wooden chip. According to this, it is possible to prevent the tar non-adsorbed wood chips from being burned by the tar-containing gas generated by the thermal decomposition, and the tar can be adsorbed to the tar non-adsorbed wood chips.

  Furthermore, by operating the gasification method or gasification apparatus 1 according to the first embodiment, it is possible to generate a tar-adsorbed wood chip having higher thermal decomposition efficiency and energy density than the tar-unadsorbed wood chip. it can. The tar-adsorbed wood chip can be used as a combustible fuel that does not require the gas source of the gasifier 1, the fuel of the generator, and the auxiliary fuel for generating fire.

The energy density of the already adsorbed tar wood chips will be described. The calorific value of the dried tar unadsorbed wood chips is about 20 MJ / kg-dry, and the bulk density of the tar-adsorbed wood chips is about 0.2 kg / L. That is, the calorific value per unit volume is at most about 4 MJ / L.
On the other hand, the bulk density of the wood component of the tar-adsorbed wooden chips is almost the same as the original tar-unadsorbed wooden chips, but the tar retention rate of the tar-unadsorbed wooden chips (tar-unadsorbed wooden chips: tar = 100: 61) In consideration of the calorific value of tar (low, estimated value: 27 MJ / kg), the bulk density of the already adsorbed wooden chips of tar is 0.2 × 1.61 = 0.32 kg / L, and the calorific value = 20 × (1 / 1.61) + 27 × (0.61 / 1.61) = 22.7 MJ / kg, calorific value per unit volume = 0.32 × 22.7 = approximately 7.3. In other words, the energy density of the tar-adsorbed wooden chip is about 1.8 times at maximum as compared with the tar-unadsorbed wooden chip.

  Further, since the tar-adsorbed wooden chips are produced by bringing a tar-containing gas generated at a temperature of several hundred degrees C. into contact with the non-tar-adsorbed wooden chips, they are dried as compared with the tar-unadsorbed wooden chips. When using tar-adsorbed wood chips as a gas source, the amount of heat required for dehydration is no longer required compared to using tar-unadsorbed wood chips containing moisture, so the thermal decomposition efficiency in gasification can be improved. it can.

(Modification 1)
The gasifier 101 according to the modified example 1 includes a step of supplying the tar non-adsorbed wood chips to the tar adsorber 3, a step of collecting the tar-adsorbed wood chips, and the recovered tar already-adsorbed wood chips to the thermal decomposition apparatus 2. This is an automated process. Tar generated by thermal decomposition of the already adsorbed wooden chips is decomposed into charcoal or light organic components in the process of circulating through the thermal decomposition apparatus 2 and the tar adsorption apparatus 3.

  FIG. 3 is a schematic diagram illustrating a configuration of the gasifier 101 according to the first modification. The front-stage wood chip agitation tank 31 and the rear-stage wood chip agitation tank 32 according to the modified example 1 have tar unadsorbed wood chip supply ports 31d and 32d formed at appropriate locations in the upper part, and the tar unadsorbed wood chip supply ports 31d, In 32d, tar-adsorbed wood chip supply hoppers 41, 41 for supplying tar unadsorbed wood chips to the tar adsorption device 3 are provided via rotary valves 42, 42.

  Further, the front-stage wood chip stirring tank 31 and the rear-stage wood chip stirring tank 32 have tar already adsorbed wood chip discharge ports 31e and 32e formed at the bottom. The tar already adsorbed wood chip discharge ports 31e and 32e are provided with tar already adsorbed wood chip collectors (collecting means) 51 for rotating the tar already adsorbed wood chips via rotary valves 52 and 52, respectively.

  The tar-adsorbed wooden chip collecting device 51 is provided with a pipe-type screw conveyor 6 (conveying means) that conveys the collected tar-adsorbed wooden chips and supplies them to the hopper 24. The screw conveyor 6 is formed, for example, by connecting a horizontal screw conveyor connected to the tar-adsorbed wood chip collector 51 and a vertical screw conveyor, and has an L shape. The horizontal screw conveyor pumps the tar-adsorbed wooden chips collected by the tar-adsorbed wooden chip collector 51 to the vertical screw conveyor. The vertical screw conveyor conveys the tar-adsorbed wooden chips that are pressure-fed from the horizontal screw conveyor upward, and the tar-adsorbed wooden chips that are vertically conveyed are discharged to the hopper 24 from a conveyor discharge port provided at the top.

  The tar non-adsorbed wooden chips are continuously fed into the tar non-adsorbed wooden chip supply ports 31d and 32d, and the rotary valves 42 and 42 are arranged so that the tar non-adsorbed wooden chips are transferred to the front wooden chip stirring tank 31 and the rear stage at a predetermined speed. It operates so as to be put into the wood chip stirring tank 32. The rotary valves 52 and 52 discharge the tar-adsorbed wooden chips at a speed that matches the charging speed of the tar-unadsorbed wooden chips, and the screw conveyor 6 conveys and supplies the tar-adsorbed wooden chips to the hopper 24.

  In the gasification method and the gasifier 101 according to the first modification, the step of supplying the tar non-adsorbed wood chips to the tar adsorber 3, the step of recovering the tar-adsorbed wooden chips, and the recovered tar-adsorbed wood The process of supplying chips to the thermal decomposition apparatus 2 can be automated, and tar-free gas can be generated.

(Embodiment 2)
FIG. 4 is a schematic diagram illustrating a configuration of the power generation device according to the second embodiment. The power generator according to Embodiment 2 of the present invention includes the gasifier 1, the motor 71, and the generator 72 described in Embodiment 1.

  The motor 71 is connected to the outlet 32 a of the gasifier 1 and is configured to be supplied with the tar-free gas generated in the gasifier 1. The engine 71 is, for example, an internal combustion engine that outputs mechanical power by mixing a tar-free gas and air, and then combusting in a cylinder (not shown) to convert chemical energy into mechanical energy.

  The generator 72 is composed of, for example, a magnet that generates a magnetic field and a coil that is rotatably arranged in the magnetic field, and the motor is rotated by the power output from the motor 71, thereby The power of 71 is converted into electric energy and an induced electromotive force is output.

  In the power generation apparatus according to the second embodiment, the gasification apparatus 1 according to the first embodiment can generate the tar-free gas and generate power using the tar-free gas.

(Embodiment 3)
FIG. 5 is an explanatory diagram conceptually showing the gasification method according to the third embodiment. In the gasification method according to Embodiment 3, first, as shown by the brackets and broken line arrows in FIG. 5, the wooden chips are heated by heating the tar unadsorbed wooden chips at 400 to 600 ° C., for example, 500 ° C. Pyrolysis into charcoal and tar containing gas. And the charcoal produced | generated by thermal decomposition is collect | recovered.

  Next, the tar-containing gas generated by the thermal decomposition is brought into contact with the porous iron ore (porous inorganic material) in the temperature range of 400 to 600 ° C., thereby reforming the tar-containing gas, that is, redox, In addition, a low tar-free gas containing hydrogen, carbon monoxide, etc. and a carbon carrier are produced together, and the carbon carrier is recovered.

The porous iron ore is, for example, a mesoporous ore mainly composed of mesoporous iron oxide, for example, hematite Fe ₂ O ₃ . The mesoporous ore is produced before the gasification of the wood chips. Specifically, porous iron ore is produced by heating low-grade iron ore, limonite ore mainly composed of iron oxide having bound water, goethite ore FeOOH, etc., and dehydrating the bound water as water vapor. . As the porous iron ore, limonite ore and goethite ore before dehydration may be directly used for reforming the tar-containing gas.

  Next, the tar-containing gas is brought into contact with the tar-unadsorbed wood chip while stirring the tar-unadsorbed wood chip with the low-tar-containing gas, thereby converting the tar contained in the low tar-containing gas into the tar-unadsorbed wood chip. Adsorb. Tar-free gas is obtained by adsorption of tar. A tar-free gas is a gas obtained by further removing tar components from a low-tar content gas, and is mainly a flammable, non-condensable gas or light organic gas containing hydrogen, carbon monoxide, carbon dioxide, lower hydrocarbon gas, etc. Contains the components vapor and water vapor.

  FIG. 6 is a schematic cross-sectional view showing a configuration example of the gasifier 301 according to the third embodiment. A gasification apparatus 301 according to Embodiment 3 includes a gas reforming apparatus 8 interposed between the thermal decomposition apparatus 2 and the tar adsorption apparatus 3. The gas reformer 8 corresponds to means for bringing the tar-containing gas into contact with the porous inorganic substance.

  The gas reformer 8 includes a vertically long cylindrical gas reforming reactor 81. The gas reforming reactor 81 is disposed in an electric furnace 84 that heats the gas reforming reactor 81. The gas reforming reactor 81 forms a moving bed or a fluidized bed of porous iron ore. For example, a hopper 82 for supplying granular porous iron ore to the gas reforming reactor 81 is provided via a rotary valve 83 at the porous iron ore charging port 81 b formed at the upper part of the gas reforming reactor 81. It has been. The gas reforming reactor 81 has a gas inlet 81a on the lower side wall, and a pipe 25 communicating with the thermal decomposition reactor 21 is connected to the gas inlet 81a, which is generated by pyrolysis of a wood chip. The tar-containing gas flows into the gas reforming reactor 81 and flows through the porous iron ore accumulation. When the tar-containing gas and the porous iron ore are contacted at a temperature of 400 to 600 ° C., a low tar-free gas and a carbon carrier from which tar is removed are produced together. The gas reforming reactor 81 has a carbon carrier discharge port 81c for discharging the carbon carrier at the lower end. The carbon carrier discharge port 81c is provided with a carbon carrier recovery device 86 that recovers the carbon carrier via a rotary valve 85. The gas reforming reactor 81 has a gas outlet 81d on the upper side wall, and one end of a pipe 87 is connected to the gas outlet 81d. The other end of the pipe 87 is connected to the preceding wood chip stirring tank 31.

  In the gasification method and gasification apparatus 301 according to Embodiment 3, part of the energy of the tar unadsorbed wood chip can be recovered as a carbon carrier as necessary.

(Embodiment 4)
FIG. 7 is an explanatory diagram conceptually showing the gasification method according to the fourth embodiment. In the gasification method according to the fourth embodiment, first, similarly to the gasification method according to the first embodiment, the tar non-adsorbed wood chip is heated at 400 to 600 ° C., for example, 500 ° C. Thermally decomposes into gas. And the charcoal produced | generated by thermal decomposition is collect | recovered.

  Next, while the tar non-adsorbed wood chip is stirred, the tar-containing gas is brought into contact with the tar non-adsorbed wood chip, thereby adsorbing the tar contained in the tar-containing gas to the tar non-adsorbed wood chip. Tar-free gas is obtained by adsorption of tar. The tar-free gas contains light organic component vapor, water vapor and non-condensable gas.

Next, the light organic component and water contained in the tar-free gas are condensed in a condenser to dissolve the tar-free gas, the gas-phase non-condensable gas, the liquid light oil and the water-soluble organic matter. Separated into water. And the separated non-condensable gas and the water which melt | dissolved the liquid light oil and water-soluble organic substance are collect | recovered. Hereinafter, water in which liquid oil and water-soluble organic substances are dissolved is referred to as bioliquid (a substance having a boiling point lower than a predetermined temperature). The main component of bioliquid is a water-soluble organic substance, and is a colorless and transparent liquid immediately after production. In addition, when the bioliquid is heated under atmospheric pressure, it has a property of volatilizing almost 100% at less than 200 degrees. Bioliquid is expected to be used as an energy source.
The main component of bio-oil that has been put to practical use overseas is heavy oil. When heavy oil is heated, 10% or more remains as carbides even when heated to 500 degrees.

  FIG. 8 is a schematic diagram showing a configuration of the gasifier 401 according to the fourth embodiment. In addition to the configuration of the gasifier 1 described in the first embodiment, the gasifier 401 according to the fourth embodiment of the present invention includes a condenser 9 provided at the gas outlet 32a of the subsequent wood chip stirring tank 32. Prepare.

The condenser 9 condenses the light organic component and water contained in the non-tar-containing gas, thereby converting the tar-free gas into bioliquid, that is, water in which light oil and water-soluble organic matter are dissolved, and non-condensable gas. To separate. The separated light oil and water in which water-soluble organic substances are dissolved and the non-condensable gas can be recovered separately.
Thus, according to the gasification method and gasification apparatus according to Embodiment 4, charcoal, non-condensable gas not containing tar, and bioliquid can be produced together.

  FIG. 9 is an explanatory diagram showing the effect of the gasification method according to the fourth embodiment. FIG. 9A is a mass flow in the case of gasifying 100 kg of tar unadsorbed wood chips using the gasification method according to the fourth embodiment, and FIG. 9B uses a conventional gasification method. The mass flow when gasifying 100 kg of tar unadsorbed wood chips. FIG. 9 shows the mass flow when the wood chip is pyrolyzed at 500 ° C.

As shown in FIG. 9B, according to the conventional gasification method, by treating 100 kg of tar unadsorbed wood chips, 24 kg of charcoal, 33 kg of light organic components and water, and 21 kg of non-condensable gas are collected. However, 22 kg of tar is also generated.
On the other hand, as shown in FIG. 9 (a), according to the gasification method according to the fourth embodiment, by treating 100 kg of tar unadsorbed wood chips, 31 kg of charcoal, 49 kg of light organic components and water, and 20 kg of non-condensable gas can be collected. Moreover, tar can be removed without performing any operation such as catalytic reforming, and 22 kg of tar can be recovered as charcoal and light organic components. Specifically, the yield of charcoal can be increased to 1.3 times (≈31 / 24) without an operation such as pressurization or the addition of a predetermined chemical substance. Further, the yield of light oil can be increased to 1.7 times (≈27 / 16) or more. In addition, light oil is 16 kg among the light oil and water shown in FIG.9 (b).

  Hereinafter, experimental results showing the effects of the gasification method according to the present invention will be described more specifically. The experimental apparatus has the same configuration as the gasifier 401 shown in FIG. 8, the tar adsorber 3 is composed of one stage of a wood chip agitation tank, and the thermal decomposition apparatus 2 and a mantle heater for keeping the pipe 25 are installed. The difference is that a silica fiber filter for confirming and quantifying the residual tar gas is interposed downstream of the tar adsorption device 3.

FIG. 10 is an explanatory diagram conceptually showing an experimental method for confirming the effect of the gasification method according to the present invention. In this experiment, a wood chip pyrolysis process, a tar adsorption process, and a condensation process are sequentially performed. Hereinafter, this series of processes is referred to as tar recycling operation.
In the first tar recycling operation, as shown in FIG. 10, 157 to 158 g tar unadsorbed wood chips are thermally decomposed. In addition, 157-158 kg is the mass of the tar non-adsorbed wood chip in a dry state. The heating temperature in the pyrolysis step is 500 ° C., and the heating time is 47 seconds. In the tar adsorption process, the inlet temperature of the tar adsorption device is maintained at 200 ° C., and the outlet temperature is maintained at 110 to 120 ° C. The silica fiber filter is kept at 150 ° C. In the condensation step, a tar-free gas is separated into a non-condensable gas, a light organic component, and water using a three-phase condenser at 0 ° C.-30 ° C.-70 ° C.
From the second time onward, the tar already adsorbed wood chips obtained in the previous tar recycling operation are thermally decomposed and the same processing is executed.

  FIG. 11 is a graph showing a change in tar yield accompanying an increase in the tar recycling operation number. The horizontal axis represents the tar recycling operation number, and the vertical axis represents the tar yield. The tar yield is the ratio of the weight of tar recovered in each tar recycling operation to the dry weight of 100 kg of the unadsorbed wooden chips.

  Since the tar non-adsorbed wood chip has been confirmed to be usable as a gasification material according to the present embodiment even when holding tar corresponding to 67% of its own weight, the yield of tar is less than 67% If there is, it is possible to implement the gasification method according to the present embodiment.

It can be seen that the rate of increase in the yield of tar accompanying the increase in the number of tar recycle operations decreases as the number of tar recycle operations increases, and has reached a steady state at a yield of about 40%.
The yield in the steady state is theoretically expressed by β / α. Where α is the conversion rate indicating the rate at which the tar adsorbed to the non-tar adsorbed wood chips is decomposed into non-tar components, and β is the heat of the non-tar adsorbed wood chips alone. It is the yield of tar obtained by decomposition.

  FIG. 12 is a graph showing changes in the yield of charcoal, water, and light organic components associated with the tar recycling operation number. 12A shows the yield of charcoal, FIG. 12B shows the yield of water, and FIG. 12C shows the yield of light organic components. The horizontal axis represents the tar recycling operation number, and the vertical axis represents the yield of charcoal, water or light organic components. The yields of charcoal, water, and light organic components are the ratios of the weight of charcoal, water, and light organic components recovered by each tar recycling operation with respect to 100 kg of the dry weight of the tar non-adsorbed wood chips. From the graph of FIG. 12, it can be seen that a part of the tar adsorbed on the already adsorbed wood chips is converted into light organic components and charcoal.

  FIG. 13 is a graph showing a change in the non-condensable gas yield accompanying an increase in the tar recycle operation number. The horizontal axis represents the tar recycling operation number, and the vertical axis represents the yield of non-condensable gas. The yield of non-condensable gas is the ratio of the weight of non-condensable gas recovered by each tar recycling operation to the dry weight of 100 kg of tar non-adsorbed wood chips. Although the reason is not clear, the yield of the non-condensable gas slightly increases to the operation number 5 and then decreases slightly, and the operation number 10 is almost the same as that of the operation number 1. Even if the proportion of tar adsorbed on the tar-adsorbed wood chips of operation number 1 increases, the weight of the recovered non-condensable gas is almost constant.

  FIG. 14 is a graph showing a change in tar conversion rate with an increase in the tar recycle operation number. The horizontal axis represents the tar recycling operation number, and the vertical axis represents the tar conversion rate. The conversion rate is a rate at which the tar is decomposed into non-tar components when the tar adsorbed on the unadsorbed wooden chips is thermally decomposed. The plot shows total conversion to tar charcoal, light organic components, water and non-condensable gases adsorbed on the tar-adsorbed wood chips. The conversion rate is kept constant at around 48% regardless of the operation number.

  In each tar recycling operation, adsorption of tar to the silica fiber filter has not been confirmed.

  From the above experimental results, the yield β / α in the steady state was less than 67%, and it was confirmed that the gasification apparatus and the gasification method according to the present invention can be actually implemented.

  In the above-described embodiment and modification, an example in which a wood chip is used as an organic material has been described. However, other organic materials such as wood may be used as long as the organic material has pores capable of adsorbing tar. Powder, paper, food waste, agricultural waste, or biofuel squeeze can be used. Agricultural waste is organic matter such as sugarcane bagasse, rice straw, straw, and rice husk.

  It should be understood that the embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Gasifier 2 Pyrolysis device (Pyrolysis means)
3 Tar adsorption device (adsorption means)
6 Screw conveyor (conveyance means)
8 Gas reformer 9 Condenser 21 Pyrolysis reactor 21a Wood chip supply port (organic matter supply port)
21b Charcoal outlet (charcoal solid outlet)
21c Exhaust port 22 Electric furnace 31 Pre-stage wood chip stirring tank (container)
32 Backstage wood chip stirring tank (container)
31a Gas inlet 31b, 32b Connection port 31d, 32d Tar unadsorbed wood chip supply port 31c, 32c Stirring blade 32a Gas outlet 33 Connection pipe 41, 41 Tar already adsorbed wood chip supply hopper 51 Tar already adsorbed wood chip collector 71 Engine 72 Generator 81 Gas reforming reactor

Claims (7)

In a gasification method for gasifying crushed or granular wood chips,
A pyrolysis step of pyrolyzing the wood chip into a tar-containing gas and a carbonaceous solid by heating the wood chip to 400 to 600 ° C;
The tar-containing gas generated by the thermal decomposition is contained in the tar-containing gas by contacting the crushed or granular wood chips before the thermal decomposition with stirring before the tar contained in the tar-containing gas is liquefied. Adsorbing step for adsorbing the tar to be adsorbed on the wood chip,
The pyrolysis step includes
Pyrolyzing the wood chips obtained by adsorbing tar in the adsorption step,
Further, by cooling the tar-free gas obtained by bringing the tar-containing gas generated by the thermal decomposition of the wooden chip adsorbed with the tar into the wooden chip before the thermal decomposition, the non-tar-containing gas is made to be inflammable. It has a step of separating a non-condensable gas from a liquid light oil that can be used as an energy source and water in which a water-soluble organic substance is dissolved, and recovering the separated liquid phase substance. Gasification method.   A power generation method comprising: generating power by burning a tar-free gas generated by the gasification method according to claim 1. In a gasifier for gasifying crushed or granular wood chips,
Pyrolysis means for pyrolyzing the wood chip into a tar-containing gas and a carbonaceous solid by heating the wood chip to 400 to 600 ° C;
The tar-containing gas generated by the thermal decomposition is contained in the tar-containing gas by contacting the crushed or granular wood chips before the thermal decomposition with stirring before the tar contained in the tar-containing gas is liquefied. Adsorbing means for adsorbing tar to be adhering to the wood chip,
A recovery means for recovering the wood chips adsorbed with tar by the adsorption means;
Transport means for transporting the wood chips recovered by the recovery means to the thermal decomposition means;
By cooling the tar-free gas obtained by contacting the tar-containing gas generated by pyrolysis of the wood chips with adsorbed tar with the wooden chips before pyrolysis, the tar-free gas is cooled to become nonflammable And a means for recovering the separated liquid phase water , which is separated into a liquid gas light oil that can be used as an energy source and water in which a water-soluble organic substance is dissolved. Gasifier. The thermal decomposition means is
Heat having a hollow cylindrical shape, having a wood chip supply port to which a wood chip is supplied on one end side, and a carbonaceous solid discharge port for discharging carbonaceous solid on the other end side and an exhaust port for exhausting tar-containing gas A cracking reactor;
A conveying screw for conveying the wood chip supplied to the pyrolysis reactor from the one end side to the other end side;
The adsorption means includes
A pipe that is connected to the pyrolysis reactor by a pipe and has a hollow cylindrical shape having an inlet into which a tar-containing gas flows and an outlet from which a tar-free gas flows out, and accommodates wood chips before pyrolysis. Body,
The gasifier according to claim 3, further comprising: a stirring blade that stirs the wood chip accommodated in the container. A gasifier according to claim 3 or claim 4,
An engine that outputs power by burning the non-tar-containing gas gasified by the gasifier;
And a generator that generates electric power using the power of the engine.   A wood chip formed by adsorbing tar using the gasification method according to claim 1 or the gasification device according to claim 3 or 4. Liquid light oil and water-soluble organic matter that can be utilized as the energy source separated by using the gasification method according to claim 1 or the gasification device according to claim 3 or claim 4 Dissolved water .

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