JP4650985B2 - Biomass gasification method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In particular, the present invention provides synthetic gas from biomass using, as raw materials, wood chips such as thinned wood, driftwood, pruned wood, construction waste, herbaceous materials such as weeds, grass, sugar cane, RDF, rice husk, cow dung, and other wastes The present invention relates to a gasification method from biomass and an apparatus therefor.
[0002]
[Prior art]
Waste that is not suitable for material recycling that reuses waste as a material is being promoted by thermal recycling that effectively uses it as an energy source, and there are advantages such as effective use of unused energy resources and the effect of reducing waste. .
[0003]
It is said that waste power generation is most effective for thermal recycling of waste, but so far, its application has been limited to large waste treatment facilities. However, in view of the current situation in which it is extremely difficult to construct a large-scale industrial waste treatment facility because of opposition from residents, it is hoped that a small-scale biomass gasification method and apparatus capable of efficiently recovering the energy held by waste will emerge. It is rare.
[0004]
[Problems to be solved by the invention]
A method for producing gas fuel from biomass using wood, herbaceous material, etc. as a raw material is already known. The main component of this gas fuel is a synthesis gas composed of hydrogen (H ₂ ) and carbon monoxide (CO). Methanol (CH ₃ OH) can be synthesized from this synthesis gas.
[0005]
However, there is still no track record of small-scale industrial equipment for producing methanol from biomass. This is because natural gas (CH ₄ ) is cheap as a raw material and cannot be economically handled, and technically it has not been successful in producing effective syngas from biomass.
[0006]
An object of the present invention is to provide a biomass gasification method and apparatus capable of efficiently producing effective synthesis gas with a small-scale apparatus.
[0007]
[Means for Solving the Problems]
The present invention, an upper end and fuel input port, an intermediate portion and the pyrolysis zone of the input biomass fuel, the combustion gasification furnace tube was hot water preheating unit to the lower end, the thermal decomposition of the combustion gasification furnace cylinder a housing portion of the passable heat retaining material of the pyrolysis gas which is provided in the lower zone, gas outlet means for deriving outside while sucking from the housing portion of the heat retaining material of fumes downwards, the gas outlet A steam chamber comprising a space from the bottom of the bottom ash partition plate to the hot water preheating portion , a combustion nozzle integrally provided at the upper end, and an open end communicating with the steam chamber at the lower end, and the combustion A combustion cylinder in which the position of the combustion nozzle is freely adjustable in a gasification furnace cylinder, and the combustion nozzle is supplied with a mixture of air and water vapor from a flame outlet for radiating a flame and the water vapor chamber. Air / steam supply holes are provided. A gasifier biomass characterized by Rukoto.
[0008]
In the configuration as described above, the biomass fuel 12 is burned in the pyrolysis zone in the combustion gasification furnace cylinder 10 to perform pyrolysis gasification, and this pyrolysis gas is put into the combustion layer zone below the pyrolysis zone. It is sucked and reacted with a mixture of high-temperature steam and air to oxidize, and further, a reformed gas is obtained in the reduction layer and reforming layer below it, and ash and unreacted tar are removed from the reformed gas. To obtain purified gas.
In addition, after obtaining the purified gas, the steam and air supplied to the reformed layer zone by the sensible heat of the purified gas passing through are heated to effectively use the energy.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
Reference numeral 10 denotes a combustion gasification furnace cylinder whose upper end is the fuel inlet 11 and whose lower end is the hot water preheating portion 27. At an intermediate position inside the combustion gasification furnace cylinder 10, a coarse upper rosttle 35 and a dense lower rooster 36 with a lattice are arranged and fixed at a slight distance from each other. A guide cylinder 21 penetrating vertically is fixedly provided below the lower rooster 36 and at the center of the combustion gasification furnace cylinder 10, and the combustion cylinder 16 is movable up and down in the guide cylinder 21. Is provided.
[0010]
A gas supply pipe 22 is integrally attached to the center of the combustion cylinder 16, and a burner 14 constituting the combustion nozzle 13 is provided at the upper end of the gas supply pipe 22 by a partition plate 17. A large number of flame openings 15 are opened around the entire circumference of the combustion cylinder 16 in which the burner 14 is housed.
A number of air / water vapor supply holes 18 are opened on the outer periphery of the combustion cylinder 16 below the flame opening 15 between the partition plate 17 and the upper rooster 35.
Between the upper rooster 35 and the lower rooster 36, a heat retaining material 54 made of an insoluble ceramic, a metal lump or the like for maintaining a temperature of 800 to 1000 ° C. is accommodated.
[0011]
The gas supply pipe 22 penetrates the central part of the hot water preheating part 27 liquid-tightly to the lower part through the packing 52 and can adjust the vertical position within the guide cylinder 21 integrally with the combustion cylinder 16. Yes. In addition, a gas introduction hole 23 and an air introduction hole 24 are provided in a portion led to the lower end portion of the gas supply pipe 22, and an ignition cable 25 is provided through the gas supply pipe 22. It is connected to the.
[0012]
An auxiliary air supply pipe 19 is connected to the combustion gasification furnace cylinder 10 at substantially the same height as the combustion nozzle 13, and the auxiliary air supply pipe 19 is connected to an air pump 41 to be described later via a valve 20. Has been.
The combustion gasification furnace cylinder 10 has a drawer-type ash receiving drawer 40 which is positioned below the lower rooster 36 and is open to the side so as to be a gas passage. . Further, an ash partition plate 48 inclined toward the ash receiving drawer 40 is fixedly provided on the guide cylinder 21 inside the combustion gasification furnace cylinder 10 at the lower part of the lower rooster 36.
[0013]
In the combustion gasification furnace cylinder 10, the space from the lower part of the ash receiving drawer 40 and the ash partition plate 48 to the hot water preheating part 27 constitutes a steam chamber 53, and the combustion gasification furnace cylinder in the steam chamber 53. An air supply port 34 connected to an air supply pipe 33 which will be described later is opened at the side of the ash partition plate 48 and is connected to the water vapor supply pipe 31. A water supply pipe 29 is connected to the inlet side of the hot water preheating unit 27 and a hot water take-out pipe 30 for circulating the hot water 28 is connected.
[0014]
A heat insulating cylinder 46 is formed on the upper outside of the combustion gasification furnace cylinder 10 by filling it with a heat insulating material 47. Further, a gas / air heat exchange cylinder 50 is formed below the heat retaining cylinder 46 and positioned on the outer circumference of the upper rostr 35, the lower rooster 36, and the ash receiving drawer 40. Further, the outer circumference of the water vapor chamber 53 is formed. An air preheating cylinder 51 is formed at the position.
[0015]
Between the gas / air heat exchange cylinder 50 and the combustion gasification furnace cylinder 10, an ash trap 37 is mounted at the upper part of the ash receiving drawer 40. 38 is provided and led out from the tar trap 38 through a reformed gas take-out pipe 39.
[0016]
The reformed gas take-out pipe 39 and the hot water take-out pipe 30 are externally connected to a heat exchanger 42, and an engine 44 and a methanol production apparatus 45 are connected to a gas outlet side of the heat exchanger 42 via a suction pump 43. The hot water outlet side of the heat exchanger 42 is connected to the water vapor supply pipe 31 via the suction pump 32.
The entire apparatus described above is mounted on the mount 49.
[0017]
Next, the operation of gasification by the apparatus of the present invention will be described.
(1) Combustion gasification furnace cylinders such as thinned wood, driftwood, pruned wood, wood chips such as building waste, herbaceous materials such as weed, grass, sugarcane waste, RDF, rice husk, cow dung, and other waste Ten fuel inlets 11 are continuously supplied from a hopper (not shown).
Immediately after activation, the combustion cylinder 16 is lowered so that the flame opening 15 is positioned between the upper rooster 35 and the lower rooster 36. In this state, gas is sent from the gas introduction hole 23 and air is sent from the air introduction hole 24, and the burner 14 is ignited by the current from the ignition cable 25. Then, a flame radiates | emits from the flame opening 15 toward the heat holding material 54, and this heat holding material 54 is heated until it reaches 800-1000 degreeC.
Water is supplied from the water supply pipe 29 to the hot water preheating unit 27 to make hot water 28, steamed by the heat exchanger 42, and steam is supplied from the steam supply pipe 31 to the steam chamber 53 by the suction pump 32. When the moisture content of the biomass fuel 12 is large, the discharge path on the outlet side of the suction pump 32 may be opened to escape to the outside without supplying water vapor from the water vapor supply pipe 31 to the water vapor chamber 53.
Further, air is supplied from the air supply pipe 33 through the air supply port 34 to the water vapor chamber 53 by the air pump 41, and at the inside of the combustion gasification furnace cylinder 10 by the suction pump 43 connected to the reformed gas take-out pipe 39. Aspirate the air.
[0018]
(2) When the heat retaining material 54 is sufficiently heated, the combustion cylinder 16 is raised to a substantially central position (position in FIG. 1) of the combustion gasification furnace cylinder 10 in which the biomass fuel 12 is stored. Then, a flame is radiated | emitted from the flame opening 15 inside the combustion gasification furnace cylinder 10, and the biomass fuel 12 starts combustion.
In addition, due to the press-fitting of air by the air pump 41 and the suction of the suction pump 43, the mixture of water vapor and air in the water vapor chamber 53 rises inside the combustion cylinder 16 and is converted into combustion gas from the air / water vapor supply hole 18. It is supplied into the furnace tube 10.
[0019]
(3) In the pyrolysis layer zone around the flame opening 15, air that is sufficiently throttled than the amount of air necessary for complete combustion is supplied, so that it is heated at a relatively low temperature of 300 to 600 ° C. and pyrolyzed. Gasification is performed. The pyrolysis gas generated here contains flammable gas such as tar and soot in addition to flammable gas such as CO and H _2. The air is sucked by the action of the suction pump 43 and sent to the lower combustion layer (oxidation layer) zone around the air / water vapor supply hole 18. In this combustion layer zone, combustion is performed mainly at 800 to 1000 ° C. by the following reaction.
C + O ₂ → CO ₂
[0020]
(4) In the reduction layer zone below the combustion layer zone, oxygen is deprived, and in the reformed layer zone below the reduction layer zone, the tar content is reformed to CO and H ₂ by the following reaction. To do.
C + CO ₂ → 2CO
C + H ₂ O → CO + H _{2
C n H m + nH 2 O} → nCO + (n + 1/2 · m) H 2
These reactions occur only at a high temperature of about 800 ° C. or more, and are endothermic reactions. Therefore, air is mixed with water vapor, and energy necessary for reforming is supplied by the next reaction.
C + O ₂ → CO ₂
C + 1/2 · O ₂ → CO
When the pyrolyzed gas is sucked downward and burned, or when passing through the gaps in the biomass fuel 12 that has not yet been burned, the gas passage once formed is fixed, and the inside of the combustion gasification furnace cylinder 10 is fixed. In some cases, the thermal decomposition may not be sufficiently performed. Therefore, by opening the valve 20 from the air pump 41 via the auxiliary air supply pipe 19 and supplying air, the gas flow path is forcibly changed so that gasification is performed uniformly.
[0021]
(5) The reforming of the tar is more reliably performed by passing through the preheated heat retaining material 54 between the upper rooster 35 and the lower rooster 36.
The ash that has passed through the upper rooster 35 and the lower rooster 36 falls to the ash partition plate 48 and accumulates in the ash receiving drawer 40. When the reformed gas passes through the ash trap 37 from the ash receiving drawer 40, the fine ash powder is removed, and further, a small amount of tar that has not been reformed by the tar trap 38 is removed to become a refined gas. It is sent to the heat exchanger 42 through the quality gas take-out pipe 39.
[0022]
(6) When high-temperature purified gas passes through the reformed gas take-out pipe 39, heat is exchanged in the gas / air heat exchange cylinder 50 and the air preheating cylinder 51, and the air in the water vapor chamber 53 is warmed by the heat, and Generates hot water vapor. Further, the hot water 28 sucked from the hot water take-off pipe 30 by the suction pump 32 is heated by the high-temperature purified gas sent from the reformed gas take-out pipe 39 to the heat exchanger 42, and is vaporized. Water vapor is supplied to the water vapor chamber 53.
[0023]
(7) The purified gas sucked by the suction pump 43 is used as a fuel gas for an industrial furnace, a boiler, an engine 44 of an internal combustion engine, and the like, and methanol (CH ₃ OH) is synthesized by the methanol manufacturing apparatus 45.
[0024]
In the above-described embodiment, in order to perform the thermal decomposition, oxidation, reduction, and reforming steps in the combustion gasification furnace cylinder 10 more completely, the type of biomass fuel 12 to be used, the water content, the cylinder interior The position of the flame opening 15, the position of the air / water vapor supply hole 18, the supply amount of air / water vapor, and the like must be optimally controlled depending on the temperature and the like.
Therefore, in the present invention, detection sensors such as temperature and humidity are attached to the respective positions of the thermal decomposition layer, the combustion layer (oxidation layer), the reduction layer, and the reforming layer. The position can be adjusted, and the amount of gas supplied from the gas introduction hole 23 and the amount of air supplied from the air introduction hole 24 can be controlled. Further, the CPU controls that the flame radiated from the burner 14 is used not only for ignition but also for combustion when the moisture content of the biomass fuel 12 is large, based on the data.
[0025]
【The invention's effect】
According to the first aspect of the present invention, the step of heating the heat retaining material in the reformed layer zone below the combustion gasification furnace cylinder with the combustion nozzle, and the position above the reforming layer zone in the combustion gasification furnace cylinder the pyrolysis zone is turned biomass fuel burning part after ignition by the combustion nozzle, the pyrolysis zone and step, the pyrolysis gas to perform pyrolysis gasification of by Riva biomass fuel to the heat The combustion layer zone below the combustion layer burns at a higher temperature than the pyrolysis zone, and the high-temperature carbon content in the ash generated in this process is sucked into the reforming layer zone below the combustion layer zone to obtain a high temperature. The process comprises a step of obtaining a reformed gas by reacting with a mixture of water vapor and air, and a step of obtaining a purified gas by reforming and removing ash and unreacted tar from the reformed gas. by sucking the downward Netsuho especially By passing through a place which is heated in the wood, tar and soot automatically, and can be reliably removed.
[0026]
According to the second aspect of the present invention, the same combustion nozzle 13 performs the heating in the step of heating the heat retaining material 54 in advance and the ignition in the step of burning the biomass fuel 12 in the pyrolysis zone to perform pyrolysis gasification. Can be done.
[0027]
According to the invention of claim 3, since the step of heating the air supplied to the reformed layer zone by the sensible heat of the purified gas passing after the step of obtaining the purified gas is added, the sensible heat of the pyrolysis gas Can be used effectively.
[0028]
According to the fourth aspect of the invention, the first heat retaining material was sufficiently heated by combustion nozzle, then since such a point fire biomass fuel by adjusting the position of the fuel nozzle, combustion gasification furnace The structure of the cylinder, the combustion nozzle, the air / water vapor supply hole, the hot water preheating unit, the water vapor chamber, and the gas outlet means is simple, and can be provided at a low cost especially as a small-scale biomass gasifier. In addition, since the generated gas is sucked downward, it sufficiently reacts with the air-fuel mixture in the water vapor chamber, and oxidation, reduction, and reforming are reliably performed.
[0029]
According to the fifth aspect of the present invention, the ash receiving drawer as the ash removing means is provided at a lower position of the heat holding material storage portion of the combustion gasification furnace cylinder, and the ash receiving drawer is provided as the heat holding material storage portion. Is connected to one end of a gas / air heat exchange cylinder provided on the outer periphery of the gas via an ash trap, and a reformed gas take-out pipe is connected to the other end of the gas / air heat exchange cylinder via a tar trap. The reformed gas take-out pipe is connected to the outside so as to exchange heat with an air preheating cylinder provided on the outer periphery of the steam chamber, and is led out to the outside, so that the mixture of air and steam in the steam chamber is effective. Heating can be performed sufficiently to effect the reforming action of the pyrolysis gas.
[0030]
According to the invention described in claim 6, the hot water preheating part is connected so as to supply water vapor to the water vapor chamber through the hot water take-out pipe, heat exchanger, suction pump, water vapor supply pipe, and the air / water vapor supply hole of the combustion cylinder Since the steam is reformed from the pyrolysis gas by supplying humidified air to the biomass fuel, the hot water can be efficiently steamed with the sensible heat of the purified gas.
[0031]
According to the invention described in claim 7, since the air supply pipe for supplying air from the external air pump is connected to the water vapor chamber, the necessary and sufficient air is supplied from the time of ignition to generate pyrolysis gas. Can be surely performed.
[0032]
According to the eighth aspect of the present invention, the auxiliary air supply pipe for supplying air from an external air pump is connected to the combustion nozzle in the combustion gasification furnace cylinder, and the combustion gasification furnace cylinder is supplied with the supplied air. since the gas flow path caused inside of the so that to force a change, it is possible to perform a reforming reaction evenly pyrolysis gasification in the combustion cylinder.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a biomass gasification method and apparatus according to the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Combustion gasification furnace cylinder, 11 ... Fuel inlet, 12 ... Biomass fuel, 13 ... Combustion nozzle, 14 ... Burner, 15 ... Flame outlet, 16 ... Combustion cylinder, 17 ... Partition plate, 18 ... Air / steam supply hole , 19 ... Sub air supply pipe, 20 ... Valve, 21 ... Guide cylinder, 22 ... Gas supply pipe, 23 ... Gas introduction hole, 24 ... Air introduction hole, 25 ... Ignition cable, 26 ... Open end, 27 ... Hot water preheating 28 ... Warm water, 29 ... Water supply pipe, 30 ... Warm water take-out pipe, 31 ... Steam supply pipe, 32 ... Suction pump, 33 ... Air supply pipe, 34 ... Air supply port, 35 ... Upper rooster, 36 ... Lower rooster, 37 ... Ash trap, 38 ... Tar trap, 39 ... Reformed gas take-out pipe, 40 ... Ash receiver / drawer, 41 ... Air pump, 42 ... Heat exchanger, 43 ... Suction pump, 44 ... Engine, 45 ... Methanol production device, 4 ... heat insulating cylinder, 47 ... heat insulating material, 48 ... ash partition plate 49 ... pedestal, 50 ... gas air heat exchanger tube, 51 ... air preheater tube, 52 ... packing, 53 ... steam chamber, 54 ... heat retaining material.

Claims (8)

A step of heating the heat retaining material in the reformed layer zone in the lower part of the combustion gasification furnace cylinder with a combustion nozzle, and a biomass fuel introduced into the pyrolysis zone located above the reformed layer zone in the combustion gasification furnace cylinder the burning portion after ignition by the combustion nozzle, and performing pyrolysis gasification of by Riva biomass fuel to the heat, the heat of the pyrolysis gases in the combustion layer zone below the said pyrolysis zone Combusting at a higher temperature than the decomposition zone, the high-temperature carbon content in the ash generated in this process is sucked into the reformed layer zone below the combustion layer zone and reacted with a mixture of high-temperature steam and air. A biomass gasification method comprising: a step of obtaining a reformed gas; and a step of obtaining a purified gas by reforming and removing ash and unreacted tar from the reformed gas.   The heating of the heat retaining material 54 and the ignition of the pyrolysis gasification step of the biomass fuel 12 are performed by moving the position of the same combustion nozzle 13. Gasification method. After the step of obtaining the purified gas, the step of heating the air supplied to the reformed layer zone by the sensible heat of the purified gas passing therethrough and the heat exchange step of heating the water and assisting the generation of water vapor are added. The biomass gasification method according to claim 1 or 2 , wherein the biomass gasification method is characterized. Combustion gasification furnace cylinder with the upper end as the fuel input port, the middle part as the thermal decomposition zone of the biomass fuel charged, and the lower end as the hot water preheating part, and the lower part of the pyrolysis zone in the combustion gasification furnace cylinder A storage portion for the heat-retaining material through which the pyrolysis gas can pass, a gas lead-out means for sucking the pyrolysis gas downward from the heat- holding material storage portion, and a bottom portion of the gas lead-out means; A steam chamber comprising a space from the lower part of the ash partition plate to the hot water preheating unit; a combustion nozzle provided integrally at the upper end; an opening end communicating with the steam chamber at the lower end; and the combustion gasification furnace tube A combustion cylinder in which the position of the combustion nozzle is freely adjustable, and an air / water vapor supply for supplying a mixture of air and water vapor from a flame port for radiating a flame and the water vapor chamber to the combustion nozzle That the hole is made Gasifier biomass to symptoms. An ash receiving drawer as an ash removal means is provided at a position below the heat holding material storage portion of the combustion gasification furnace cylinder, and the ash receiving drawer is provided on the outer periphery of the heat holding material storage portion. -Connected to one end of the air heat exchange cylinder via an ash trap, and connected to the other end of the gas / air heat exchange cylinder via a tar trap, a reformed gas take-out pipe, 5. The biomass gasification apparatus according to claim 4, wherein the biomass gasification apparatus penetrates through an air preheating cylinder provided on the outer periphery of the water vapor chamber so as to exchange heat . The hot water preheating section is connected to supply water vapor to the water vapor chamber via the hot water extraction pipe, heat exchanger, suction pump, and water vapor supply pipe, and the humidified air is supplied from the combustion cylinder air / water vapor supply hole to the biomass fuel. The biomass gasification apparatus according to claim 4 or 5, wherein steam reforming of the pyrolysis gas is performed by supplying to the steam. 7. The biomass gasification apparatus according to claim 4 , wherein an air supply pipe for supplying air from an external air pump is connected to the water vapor chamber. A secondary air supply pipe that supplies air from an external air pump is connected to the combustion nozzle in the combustion gasification furnace cylinder, and the gas flow path generated inside the combustion gasification furnace cylinder is forced by the supplied air. gasifier biomass according to claim 4, 5, 6 or 7, wherein it has in so that change basis.

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