JP2003049177A - Biomass gasification method and apparatus - Google Patents

Abstract

(57) [Summary] [Problem] Effective and high-quality synthesis gas is produced by a small-scale device.
To provide a biomass gasification method and apparatus that can be efficiently produced. SOLUTION: The heating of the heat retaining material 54 and the ignition of the biomass fuel 12 are performed by the same combustion nozzle 13, and the biomass fuel 12 is burned in a pyrolysis zone in a combustion gasification furnace tube 10 to be converted into a pyrolysis gas. The pyrolysis gas is sucked into the combustion layer zone at the lower position, oxidized by reacting with a mixture of high-temperature steam and air, and is further obtained in the reducing layer and the reforming layer. Further, ash and unreacted tar are removed to obtain a high-quality purified gas. Further, after obtaining the purified gas, the steam and the air supplied to the reforming zone by the latent heat of the purified gas passing therethrough are heated to effectively use energy.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention particularly relates to wood chips such as thinned wood, driftwood, pruned wood, construction waste wood, herbaceous materials such as weeds, grasses, sugar canes, RDF, chaff, cow dung, and other waste materials. TECHNICAL FIELD The present invention relates to a method and apparatus for gasifying biomass to obtain synthetic gas from biomass.

[0002]

2. Description of the Related Art Regarding waste that is not suitable for material recycling, where waste is reused as material, thermal recycling is being promoted, which effectively uses it as an energy source. Effective utilization of unused energy resources and reduction of waste There are advantages such as.

For thermal recycling of waste, it is said that waste power generation is most effective, but until now, its application is limited to large-scale waste treatment facilities. But,
In view of the current situation where it is extremely difficult to construct a large-scale industrial waste treatment facility from the opposition of the residents, the advent of a small-scale biomass gasification method and device that can efficiently recover the energy held by waste is desired. There is.

[0004]

A method for producing a gas fuel from biomass by using wood, grass or the like as a raw material is already known. The main component of this gas fuel is hydrogen (H ₂ ).
And carbon monoxide (CO). Methanol (CH ₃ OH) can be synthesized from this synthesis gas.

[0005] However, there is still no record of small-scale, industrial equipment for producing methanol from biomass.
This is because natural gas (CH ₄ ) is cheap as a raw material, so that it is not economically feasible and it has not been technically successful in producing effective syngas from biomass.

[0006] It is an object of the present invention to provide a biomass gasification method and apparatus capable of efficiently producing effective synthesis gas with a small-scale apparatus.

[0007]

The present invention is directed to a combustion gasification furnace cylinder 10 into which a biomass fuel 12 is charged, and a combustion nozzle 1 provided in the combustion gasification furnace cylinder 10 and integrally formed.
3 is provided so that its position can be adjusted, an air / steam supply hole 18 formed in the combustion cylinder 16 at a position slightly lower than the combustion nozzle 13, and a lower part of the combustion gasification furnace cylinder 10. While accommodating the storage portion for the heat retaining material 54, the steam chamber 53 provided so as to face the opening end 26 at the lower end of the combustion cylinder 16, and the pyrolysis gas generated in the combustion gasification furnace cylinder 10 downward, A biomass gasifier, characterized in that it comprises a means for leading it to the outside.

In the above-mentioned structure, the biomass fuel 12 is burned in the pyrolysis zone in the combustion gasification furnace barrel 10 to perform pyrolysis gasification, and the pyrolysis gas is burned at a position below the pyrolysis zone. It is sucked into the layer zone and reacted with a mixture of high temperature steam and air to oxidize it, and further reformed gas is obtained in the reducing layer and reforming layer therebelow. From this reformed gas, ash and unreacted tar Are removed to obtain a purified gas. Also,
After obtaining the purified gas, the steam and air supplied to the reforming layer zone due to the latent heat of the passing purified gas are heated to effectively use the energy.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. 10 has a fuel inlet 11 at the upper end
The lower end is the combustion gasification furnace tube having the warm water preheating section 27. At an intermediate position inside the combustion gasification furnace tube 10, a coarse upper grate 35 of a lattice and a lower grate 36 of a dense lattice are arranged and fixed at a slight distance from each other.
Further, below the lower roast 36 and in the center of the combustion gasification furnace tube 10, a guide tube 21 that penetrates vertically is provided.
Is fixedly provided, and the combustion cylinder 16 is attached to the guide cylinder 21.
Is provided so that it can move up and down.

A gas supply pipe 22 is integrally attached to the center of the combustion cylinder 16, and a burner 14 constituting a combustion nozzle 13 is partitioned by a partition plate 17 at the upper end of the gas supply pipe 22. A large number of flame outlets 15 are provided all around the combustion cylinder 16 in which the burner 14 is housed.
Is open. A plurality of air / steam supply holes 18 are formed on the outer periphery of the combustion cylinder 16 below the flame port 15 and between the partition plate 17 and the upper rustle 35. A heat retaining material 54 made of a non-melting ceramic, a metal lump or the like for retaining a temperature of 800 to 1000 ° C. is housed between the upper rost 35 and the lower rostr 36.

The gas supply pipe 22 is connected to the hot water preheating unit 2
The central portion of 7 is liquid-tightly penetrated to the lower portion via the packing 52, and the vertical position can be adjusted in the guide cylinder 21 integrally with the combustion cylinder 16. Also, this gas supply pipe 2
A gas introducing hole 23 and an air introducing hole 24 are provided in a portion led out to the lower end of 2, and an ignition cable 25 is provided so as to penetrate the gas supply pipe 22.
4 is connected.

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 via a valve 20 to an air pump described later. 41 is connected. Further, in the combustion gasification furnace cylinder 10, a drawer type ash receiver drawer 40 located at a lower portion of the lower roast 36 can be moved forward and backward,
Moreover, it is opened to the side so as to serve as a gas passage. Further, an ash partition plate 48 that is inclined toward the ash receiver drawer 40 is fixedly provided to the guide cylinder 21 inside the combustion gasification furnace cylinder 10 below the lower rustle 36.

In the combustion gasification furnace tube 10, the ash receiver drawer 40 and the ash partition plate 48 are arranged under the hot water preheating section 2 from below.
The space up to 7 constitutes a steam chamber 53, and the side surface of the combustion gasification furnace cylinder 10 in the steam chamber 53 is located slightly below the ash partition plate 48 and is to be described later with an air supply pipe. The air supply port 34 to which 33 is connected is opened, and the steam supply pipe 31 is connected. 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 also connected.

A heat insulating cylinder 46 is formed by filling a heat insulating material 47 on the upper outside of the combustion gasification furnace cylinder 10. Further, a gas / air heat exchange cylinder 50 is formed below the heat retaining cylinder 46 and on the outer circumference of the upper rustle 35, the lower rustle 36, and the ash receiver drawer 40, and further, the outer circumference of the water vapor chamber 53. Located in the air preheating cylinder 5
1 is formed.

An ash trap 37 is installed between the gas / air heat exchange cylinder 50 and the combustion gasification furnace cylinder 10 at the upper part of the ash receiver drawer 40, and 180
A tar trap 38 is provided on the opposite side, and the tar trap 38 is led to the outside through a reformed gas extraction pipe 39.

The reformed gas take-out pipe 39 and the hot water take-out pipe 30 are externally connected to a heat exchanger 42. At the gas outlet side of the heat exchanger 42, an engine 44 and methanol are provided via a suction pump 43. It is connected to the manufacturing apparatus 45, and the hot water outlet side of the heat exchanger 42 is connected to the steam supply pipe 31 via the suction pump 32. The entire apparatus described above is mounted on the mount 49.

Next, the operation of gasification by the apparatus of the present invention will be described. (1) As biomass, wood chips such as thinned wood, driftwood, pruned wood, construction waste wood, weeds, pasture, herbaceous materials such as sugar cane waste wood, RDF, rice husks, cow dung, and other waste are burned in a gasification furnace. 10 is continuously charged into the fuel charging port 11 from a hopper (not shown). Immediately after the combustion cylinder 16 is started, the flame port 15 has the upper rostrut 35 and the lower rostrut 3
It is descending so that it can be positioned between 6 and. In this state, gas is sent from the gas introduction hole 23, air is sent from the air introduction hole 24, and the burner 14 is ignited by the current from the ignition cable 25. Then, the flame radiates from the flame port 15 toward the heat retaining material 54, and the heat retaining material 54
Is heated to 800-1000 ° C. Water is supplied from the water supply pipe 29 to the warm water preheating unit 27 to produce hot water 28, which is 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 high, the discharge passage on the outlet side of the suction pump 32 may be opened to escape outside without supplying steam from the steam supply pipe 31 to the steam chamber 53. Further, the air pump 41 supplies air from the air supply pipe 33 to the steam chamber 53 through the air supply port 34, and the suction pump 43 connected to the reformed gas take-out pipe 39 connects the inside of the combustion gasification furnace cylinder 10. Inhale the air.

(2) When the heat retaining material 54 is sufficiently heated,
The combustion cylinder 16 is lifted 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, the flame is emitted from the flame port 15 into the combustion gasification furnace tube 10.
The biomass fuel 12 is radiated inside and starts to burn. Further, the mixture of steam and air in the steam chamber 53 rises inside the combustion cylinder 16 due to the pressurization of air by the air pump 41 and the suction of the suction pump 43, and combustion gasification from the air / steam supply hole 18 is performed. It is supplied into the furnace barrel 10.

(3) In the thermal decomposition zone around the flame port 15, the air is heated at a comparatively low temperature of 300 to 600 ° C. by supplying the air sufficiently narrowed down than the air amount necessary for complete combustion. Pyrolysis gasification is performed. The pyrolysis gas generated here contains combustible gases such as CO and H ₂ as well as combustible components such as tar and soot. In particular, the tar component is solidified when cooled, and therefore is heated. As it is, it is sucked by the action of the suction pump 43,
It is sent to the lower combustion layer (oxidized layer) zone around the steam supply holes 18. In this combustion zone, 800-100
At 0 ° C., combustion mainly takes place by the following reactions. C + O ₂ → CO ₂

(4) Oxygen is deprived in the reducing layer zone below the combustion layer zone, and further, in the reforming layer zone below this reducing layer zone, the tar content is converted into CO and H ₂ by the following reaction. And reform. 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 do not occur unless they are at a high temperature of about 800 ° C. or more, and are endothermic reactions. Therefore, the steam is mixed with air to supply the energy required for reforming by the following reaction. C + O ₂ → CO ₂ C + 1/2 ・ O ₂ → CO When the thermally decomposed gas is sucked downward and burned, or when passing through the gap of the biomass fuel 12 which is not yet burned, the passage of the gas once formed May be fixed, and there may occur a portion in the combustion gasification furnace tube 10 where thermal decomposition is not sufficiently performed. Therefore, by opening the valve 20 from the air pump 41 through the sub air supply pipe 19 to supply air, the gas flow path is forcibly changed so that gasification is evenly performed.

(5) The tar content is reformed by the upper loss 3
It is performed more reliably by passing through the preheated heat retaining material 54 between the No. 5 and the lower roast 36. The ash that has passed through the upper rustler 35 and the lower rustler 36 falls on the ash partition plate 48 and is collected in the ash receiver drawer 40. When the reformed gas passes through the ash trap 37 from the ash receiving drawer 40, fine powder of ash is removed, and further, the tar trap 38 removes a small amount of unreacted tar content and becomes a purified gas. Quality gas extraction pipe 39
And is sent to the heat exchanger 42.

(6) When the high-temperature purified gas passes through the reformed gas extraction pipe 39, heat is exchanged in the gas / air heat exchange cylinder 50 and the air preheat cylinder 51, and the heat warms the air in the steam chamber 53. And, high temperature steam is generated. Further, the high temperature purified gas sent from the reformed gas take-out pipe 39 to the heat exchanger 42 heats the hot water 28 sucked from the hot water take-out pipe 30 by the suction pump 32 to turn it into steam, and then from the steam supply pipe 31. Steam is supplied to the steam chamber 53.

(7) The purified gas sucked by the suction pump 43 is used as a fuel gas for the industrial furnace, the boiler, the engine 44 of the internal combustion engine, and the like, and the methanol producing apparatus 4 is used.
5, methanol (CH ₃ OH) is synthesized.

In the above embodiment, the combustion gasification furnace tube 10
In order to complete the thermal decomposition, oxidation, reduction, and reforming processes in the plant, the biomass fuel 12
Depending on the type, content of water, temperature in the cylinder, etc.
The position of No. 5, the position of the air / steam supply hole 18, the supply amount of air / steam, etc. must be controlled optimally. Therefore, in the present invention, detection sensors for temperature, humidity and the like are attached to each position of the thermal decomposition layer, the combustion layer (oxidation layer), the reduction layer, and the reforming layer, and based on this data, the CPU detects the upper and lower sides of the combustion cylinder 16. 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 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, etc., is controlled by the CPU based on the above data.

[0025]

According to the first aspect of the present invention, the step of heating the heat retaining material 54 in advance, the step of burning the biomass fuel 12 in the pyrolysis zone to perform pyrolysis gasification, and the pyrolysis gas In a combustion layer zone, a step of sucking into a reforming layer zone below the combustion layer zone to react with a mixture of high temperature steam and air to obtain a reformed gas,
Since the ash and unreacted tar are removed from this reformed gas to obtain a purified gas, by sucking the pyrolysis gas downward, in particular, it passes through the heated portion of the heat retaining material. By doing so, tar and soot can be removed automatically and reliably.

According to the second aspect of the present invention, 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 carry out the pyrolysis gasification are the same. It can be performed by the combustion nozzle 13.

According to the invention of claim 3, after the step of obtaining the purified gas, a step of heating the mixture of steam and air to be supplied to the reforming layer zone by the latent heat of the passing purified gas is added. The latent heat of pyrolysis gas can be effectively used.

According to the fourth aspect of the invention, the heat retaining material 54 is sufficiently heated by the combustion nozzle 13 first, and then the position of the combustion nozzle 13 is adjusted to ignite the biomass fuel 12. , The combustion gasification furnace tube 10, the combustion nozzle 13, the air / steam supply hole 18, the hot water preheating section 27, the steam chamber 53, and the means for discharging the gas downward while sucking it out are simple, It can be provided at a low cost as a large-scale biomass gasifier. Further, since the generated gas is sucked downward, it sufficiently reacts with the air-fuel mixture in the water vapor chamber 53, and the oxidation / reduction / reformation is reliably performed.

According to the fifth aspect of the present invention, an ash removing means is provided between the air / steam supply hole 18 inside the combustion gasification furnace tube 10 and the warm water preheating section 27, and the ash removing means is provided. Since the gas generated from the gas flows around the outer periphery of the combustion gasification furnace cylinder 10, and the gas / air heat exchange cylinder 50 for exchanging heat between the air in the combustion gasification furnace cylinder 10 and the mixture of steam is provided, The mixture of air and water vapor in the water vapor chamber 53 can be effectively heated to sufficiently perform the reforming action of the pyrolysis gas.

According to the sixth aspect of the present invention, the hot water preheating section 27 is connected via the hot water take-out pipe 30, the heat exchanger 42, the suction pump 32, and the steam supply pipe 31 so as to supply steam to the steam chamber 53. And the heat exchanger 42
Further, since the reformed gas take-out pipe 39 for drawing out the pyrolysis gas from the gas / air heat exchange tube 50 for heating the hot water 28 to turn it into steam is connected, the hot water 28 is efficiently retained by the purified gas. It can be steamed with latent heat.

According to the invention of claim 7, the water vapor chamber 5
Air supply pipe 33 for supplying air from the air pump 41 to 3
Since it is connected, necessary and sufficient air can be supplied from the time of ignition to reliably generate the pyrolysis gas.

According to the eighth aspect of the invention, the sub-air supply pipe 19 for supplying air from the air pump 41 is connected so as to face the combustion nozzle 13 in the combustion gasification furnace cylinder 10, so that the inside of the combustion cylinder 16 is connected. Thus, it is possible to carry out pyrolysis gasification and reforming reaction evenly.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a biomass gasification method and apparatus according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

3 is a sectional view taken along line BB in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Combustion gasification furnace cylinder, 11 ... Fuel injection port, 12 ... Biomass fuel, 13 ... Combustion nozzle, 14 ... Burner, 15
... Flame port, 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, 2
4 ... Air introduction hole, 25 ... Ignition cable, 26 ... Open end, 27 ... Warm water preheating part, 28 ... Warm water, 29 ... Water supply pipe, 3
0 ... Hot water take-out pipe, 31 ... Steam supply pipe, 32 ... Suction pump, 33 ... Air supply pipe, 34 ... Air supply port, 35 ...
Upper rustle, 36 ... Lower rustle, 37 ... Ash trap, 38 ... Tar trap, 39 ... Reformed gas extraction pipe, 40 ... Ash receiving drawer, 41 ... Air pump, 42 ...
Heat exchanger, 43 ... Suction pump, 44 ... Engine, 45 ...
Methanol production equipment, 46 ... Insulating cylinder, 47 ... Insulation material, 4
8 ... Ash partition plate, 49 ... Stand, 50 ... Gas / air heat exchange cylinder, 51 ... Air preheating cylinder, 52 ... Packing, 53 ... Water vapor chamber, 54 ... Heat retaining material.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K061 AA23 AB02 AC17 BA01 CA01                       FA12 FA25                 3K078 AA01 BA08 CA03 CA07 CA12                       CA21                 4D004 AA01 AA02 AA12 AA46 BA03                       CA27 CB31 CB34

Claims (8)

[Claims] 1. A step of heating a heat retaining material 54 in a reforming layer zone below a combustion gasification furnace tube 10 by a combustion nozzle 13, and burning a biomass fuel 12 in a pyrolysis zone in the combustion gasification furnace tube 10. A step of performing partial combustion after ignition by the nozzle 13 and performing pyrolysis gasification of the biomass fuel in the combustion layer and the outer periphery by the heat, and the pyrolysis gas is reformed in the combustion layer zone below the pyrolysis zone. A step of sucking into the layer zone to react a mixture of high temperature steam and air and a high temperature carbon content in the ash generated in the process to obtain a reformed gas, and ash and unreacted tar from this reformed gas Reforming minutes
And a step of removing the purified gas to obtain a purified gas. 2. The heating in the heating step of the heat retaining material 54 and the ignition in the pyrolysis gasification step of the biomass fuel 12 are performed by moving the same combustion nozzle 13 position. 1. The method for gasifying biomass according to 1. 3. After the step of obtaining the purified gas, a step of heating the air supplied to the reforming layer zone due to the latent heat of the passing purified gas and a heat exchange step of heating water to assist generation of steam are added. The method for gasifying biomass according to claim 1, wherein 4. A combustion gasification furnace cylinder 10 into which a biomass fuel 12 is charged, and a combustion gasification furnace cylinder 10 provided therein.
A fuel cylinder 16 provided with an integrally formed combustion nozzle 13 whose position can be adjusted freely, an air / steam supply hole 18 formed in the combustion cylinder 16 at a position slightly lower than the combustion nozzle 13, and the combustion gasification furnace cylinder 10, a storage portion for heat-retaining material 54 provided in the lower portion, a steam chamber 53 provided so as to face the opening end 26 at the lower end of the combustion cylinder 16, and a pyrolysis gas generated in the combustion gasification furnace cylinder 10. And a means for discharging the above to the outside while sucking it downward, a gasifier for biomass. 5. An ash removing means is provided between the air / steam supply hole 18 and the steam chamber 53 inside the combustion gasification furnace cylinder 10, and the gas generated from the ash removing means is combusted and gasified. 5. The gas of biomass according to claim 4, further comprising a gas / air heat exchange cylinder 50 which is arranged around the outer periphery of the furnace cylinder 10 and exchanges heat between the air and steam in the steam chamber 53. Device. 6. The hot water take-out pipe 3 from the hot water preheating section 27.
0, heat exchanger 42, suction pump 32, steam supply pipe 31
Through steam, so that steam is supplied to the steam chamber 53, and humidified air is supplied to the biomass fuel 12 from the air / steam supply hole 18 of the combustion nozzle 13 to perform steam reforming of the pyrolysis gas. The gasifier for biomass according to claim 5, characterized in that. 7. The biomass gasification apparatus according to claim 4, wherein an air supply pipe 33 for supplying air from an air pump 41 is connected to the water vapor chamber 53. 8. A gas path generated inside the combustion gasification furnace tube 10 is fixed by facing a combustion nozzle 13 in the combustion gasification furnace tube 10 and connecting an auxiliary air supply pipe 19 for supplying air from a blowing means. The gasification apparatus of biomass according to claim 5, wherein the gasification apparatus changes the gasification.