JP2009138107A - Internally circulating fluidized bed type low-temperature catalytic gasifier furnace apparatus and gasification decomposition treatment method for livestock wastes using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and easy to operate internally circulating fluidized bed type low-temperature catalytic gasifier furnace apparatus capable of greatly improving thermal efficiency and reducing cost, and a gasification decomposition treatment method for livestock wastes using the same. <P>SOLUTION: The internally circulating fluidized bed type low-temperature catalytic gasifier furnace apparatus is provided with: a partition bulkhead 17 of which the lower edge is buried in a fluidized bed so that a heat medium 13a of a fluidized bed 13 installed in a gasification furnace 14a is capable of circulating thereunder; a gasification chamber 12 for a biomass material partitioned from a combustion chamber 4 by the partition bulkhead 17; and the combustion chamber 4 for combusting the gas decomposition residue of the biomass material transferred from the gasification chamber 12 through the fluidized bed, characterized in that a heavy gas decomposition apparatus 7 is installed in the gasification chamber 12, which is filled with a catalyst facilitating decomposition or reforming heavy gas in the gas generated by the gasification of the biomass material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal circulation type fluidized bed low-temperature contact gasification furnace apparatus and a method for gasification and decomposition treatment of livestock excreta using the same.

  Attempts have been made to reuse the energy of woody materials such as thinned wood and pruned branches, biomass such as activated sludge and paper sludge by heat treatment and gasification, but the efficiency of gasification is generally poor. The cost increases, and there are few examples of stable operation with a small and low-priced device.

  As a means to increase the efficiency of gasification and reduce costs, it is conceivable to increase the thermal efficiency with a large-scale equipment, but such a large-scale equipment is used by small livestock farmers in a small area. In Japan, where a large number of dispersed forms are often used, for example, in the case of a livestock excrement disposal apparatus, it is extremely unsuitable. Therefore, the fact is that development of a gas decomposition apparatus that is small in size, low in price, and easy to operate is awaited.

  Conventionally, as a gas decomposition apparatus for woody biomass, a small one has been proposed (Patent Document 1). This apparatus has a rotary kiln type gasification structure, has a structure for conveying the pyrolysis residue generated in the primary gasification furnace to an external pyrolysis residue combustion furnace, and hot air from the pyrolysis residue combustion furnace. Is introduced into the primary gasifier to improve thermal efficiency. In addition, the generated gas generated in the primary gasification furnace is guided to the reforming furnace, and thermal decomposition treatment of tar content and harmful gas contained in the generated gas is performed.

Patent Document 2 proposes an internal circulation type fluidized bed gasifier using various wastes, coal, and the like as raw materials. This device is a fluidized bed gasification furnace that can easily and accurately control the circulation amount of the fluidized medium and easily and stably transfer the pyrolysis residue and heat between the gasification chamber and the combustion chamber. .
JP 2004-352960 A JP 2007-24492 A

  However, in the apparatus of Patent Document 1, high temperature treatment from 900 ° C. to 1000 ° C. or more is indispensable for removing heavy gas content and harmful gas contained in the generated gas, resulting in a decrease in thermal efficiency and consequently cost increase. There was a problem of becoming.

  Also, in the apparatus of Patent Document 2, the operating temperature of the apparatus is substantially 800 ° C. to 1000 ° C., resulting in a decrease in thermal efficiency and resulting in an increase in cost, which inevitably becomes a large-scale apparatus. There was a problem of not getting.

  The present invention has been made in view of the circumstances as described above, can greatly improve the thermal efficiency, can reduce tar-like products and suppress deterioration of equipment, maintenance costs, cleaning costs, etc. The internal circulation type fluidized-bed low-temperature contact gasifier for gasifying biomass raw materials such as livestock excreta and gasification of livestock excreta using the same can be reduced. It is an object to provide a decomposition processing method.

  The present invention is characterized by the following in order to solve the above problems.

  1stly, the internal circulation type fluidized bed type low temperature contact gasification furnace apparatus of this invention is an internal circulation type fluidized bed type low temperature contact gasification furnace apparatus for gasifying and decomposing a biomass raw material, A fluidized bed made of a flowable heat medium laid inside, a partition wall whose lower end is embedded in the fluidized bed so that the heat medium can be circulated through the lower side, and one partitioned by the partition wall A gasification chamber in which biomass raw material is gasified in the presence of a gasifying agent and the other chamber partitioned by a partition wall, and in the presence of an oxidizing agent, And a combustion chamber for burning the gas decomposition residue of the biomass raw material that has been moved through, and the gasification chamber is filled with a catalyst that promotes the decomposition or reforming of the heavy gas in the gas produced by the gasification of the biomass raw material. Heavy Wherein the gas decomposition device is provided.

  Second, in the first internal circulation fluidized bed type low temperature contact gasification furnace apparatus, a gasifying agent supply port for supplying a gasifying agent to the fluidized bed at the bottom of the gasification chamber, and a fluidized bed at the bottom of the combustion chamber And an oxidizing agent supply port for supplying the oxidizing agent.

  Third, in the first or second internal circulation type fluidized bed low-temperature contact gasification furnace apparatus, the lower end is embedded in the fluidized bed so that the heat medium can be circulated through the lower side thereof. At least one partition wall for adjusting the circulation movement of the medium, and at least one partition wall for adjusting the circulation movement of the heat medium, which is erected from the bottom of the fluidized bed so that the heat medium can be circulated through the upper side thereof It is characterized by providing either or both.

  Fourth, in any one of the first to third internal circulation type fluidized bed low-temperature contact gasification furnace apparatuses, the catalyst charged in the heavy gas decomposition apparatus is nickel containing nickel-supporting lignite and nickel-supporting alumina. It is a metal catalyst of Group VIII such as an iron-based catalyst or an iron-based catalyst containing limonite.

  Fifth, the method for gasification and decomposition of livestock excrement according to the present invention supplies the livestock excrement as a biomass raw material to any one of the first to fourth internal circulation fluidized bed low temperature contact gasifiers, It is characterized in that livestock waste is gasified in the gasification chamber, and the gas produced by gasification is introduced into a heavy gas decomposition apparatus to decompose or reform the heavy gas in the product gas.

  Sixth, in the fifth method for gasification and decomposition of livestock waste, the gasification temperature of livestock waste in the gasification chamber and the decomposition or reforming temperature of heavy gas in the heavy gas decomposition apparatus are 500 to 700 ° C. It is within the range.

  According to the first aspect of the invention, the partition wall having the lower end embedded in the fluidized bed partitions the gasification chamber and the combustion chamber for gasifying the biomass raw material and gasses the heavy gas decomposition apparatus filled with the catalyst. Because it is provided in the gasification chamber, heat that sufficiently promotes heavy gas decomposition is generated from the combustion chamber by using the internal combustion heat generated by combustion of the gas decomposition residue of the biomass feedstock that has moved from the gasification chamber through the fluidized bed. Supplied to heavy gas decomposition equipment in chemical chamber.

  Therefore, when the heavy gas cracking device is installed outside, the supply of external heat energy required for heating can be covered by the internal combustion heat from the combustion of the biomass raw material gas cracking residue, Thermal efficiency is greatly improved. And since thermal efficiency can be improved significantly, the size of the apparatus can be reduced.

  According to the second aspect, the gasification chamber and the combustion chamber are supplied by controlling the flow rate of the gasifying agent from the gasifying agent supply port and the oxidizing agent from the oxidant supply port to the fluidized bed. The heat medium can be circulated appropriately between the two. As a result, the thermal energy supplied to the gasification chamber and the heavy gas cracking device in the gasification chamber can be adequately covered by the internal combustion heat generated by the combustion of the gas decomposition residue of the biomass raw material, thereby greatly improving the thermal efficiency. .

  According to the third aspect of the invention, the heat medium can be appropriately circulated between the gasification chamber and the combustion chamber by providing the partition wall in order to adjust the circulation and movement of the heat medium. As a result, the thermal energy supplied to the heavy gas decomposition apparatus in the gasification chamber can be appropriately covered by the internal combustion heat generated by the combustion of the gas decomposition residue of the biomass raw material, so that the thermal efficiency is greatly improved.

  According to the fourth aspect of the invention, the catalyst charged in the heavy gas cracking apparatus is a nickel-based catalyst containing nickel-supported lignite and nickel-supported alumina, or a Group VIII metal-based catalyst such as an iron-based catalyst containing limonite. Therefore, it is possible to perform the gasification of biomass feedstock and the decomposition or reforming of the heavy gas in the heavy gas decomposition apparatus at an operating temperature significantly lower than that of the conventional apparatus, for example, 500 to 700 ° C. it can. As a result, significant energy savings can be achieved, and the nickel-supported lignite catalyst is extremely cheap compared to general catalysts for gas decomposition, and thus the size and cost of the apparatus can be reduced. The operation of the apparatus can also be facilitated.

  According to the fifth and sixth aspects of the invention, livestock excreta produces less heavy gas than woody waste and can be operated with less load. And since heavy gas in the generated gas by gasification of livestock waste can be effectively decomposed and removed even at a low temperature of, for example, 500 to 700 ° C., facilities and piping caused by tar-like products caused by heavy gas Maintenance costs and cleaning costs caused by deterioration can be reduced, and as a result, the operating cost of the apparatus can be greatly reduced.

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

  FIG. 1 is a schematic diagram showing a configuration of an internal circulation type fluidized bed low temperature contact gasification test furnace in an embodiment of the present invention. An internal circulation type fluidized bed type low temperature contact gasification furnace apparatus 14 shown in the figure is for gasifying and decomposing a biomass raw material 8 such as livestock excreta, particularly livestock excreta. It has a gasification furnace 14a with a length of about 2 m and a furnace width of about 40 cm.

  A fluidized bed 13 made of a flowable heat medium 13a such as foundry sand is laid in the gasification furnace 14a.

  The gasification furnace 14 a is partitioned into a gasification chamber 12 and a combustion chamber 4 by a partition wall 17. An upper end portion of the partition wall 17 is fixed to a furnace wall or the like, and a lower end portion thereof is a gas so that the heat medium 13a can circulate between the gasification chamber 12 and the combustion chamber 4 through the lower side thereof. It is embedded in the fluidized bed 13 in a state where it floats from the bottom of the conversion furnace 14a.

  Below the gasification chamber 12, a gasifying agent supply port 10 for supplying the gasifying agent into the fluidized bed 13 constituting the gasification region 9 is disposed. On the other hand, below the combustion chamber 4, a plurality of oxidant supply ports 11 a to 11 e for supplying an oxidant into the fluidized bed 13 constituting the oxidation region 5 are arranged along the circulation direction.

  In the combustion chamber 4, partition walls 15 and 16 for adjusting the circulation movement of the heat medium 13a are disposed. Of these, the partition wall 16 on the partition wall 17 side is fixedly installed on the bottom of the fluidized bed so that the heat medium 13a can circulate by overflowing the upper side, and the partition wall 16 is opposite to the partition wall 17. The partition wall 15 is fixed to a furnace wall or the like so that the heat medium 13a can be circulated through the lower side thereof, and is embedded in the fluidized bed 13 in a state of floating from the bottom of the gasification furnace 14a.

  A gasifying agent such as water vapor and carbon monoxide having a precisely controlled flow rate is supplied from the gasifying agent supply port 10 into the fluidized bed 13, and the gasifying agent supply ports 11a to 11e supply the gasifying agent 13 precisely. By supplying an oxidant such as oxygen and air at a controlled flow rate, the heat medium 13a of the fluidized bed 13 passes below the partition wall 17, overflows the partition wall 16, and flows below the partition wall 15. It is designed to circulate through the entire gasification furnace 14a by passing through.

  For example, by individually and precisely controlling the flow rate of the gasifying agent from the gasifying agent supply port 10 and the flow rate of the oxidant from the oxidant supply ports 11a to 11e (in FIG. 1, supply with a high flow rate schematically). The mouth and the number of supply ports are indicated by the thickness of the arrow line.) The heat medium 13a flows accordingly.

  The gasification chamber 12, which is one chamber partitioned by the partition wall 17, is supplied with a biomass material 8 such as livestock dung that has been appropriately dried. The degree of drying is preferably a water content of 40% by mass or less, more preferably a water content of 15% by mass or less. If the water content exceeds 40% by mass, the thermal efficiency may decrease.

  Examples of the biomass raw material 8 suitable for the gasification and decomposition treatment by the internal circulation type fluidized bed low-temperature contact gasification furnace apparatus 14 of the present embodiment include livestock manure that has been composted. The composted livestock manure has a low water content, and moreover, the amount of tar-like products caused by heavy gas is less than that of wood-based waste. There is little load.

  The biomass raw material 8 can be supplied into the gasification chamber 12 by direct supply from a hopper or by a screw type extruder. In particular, a screw type that can reduce the influence of odor and internal pressure and can be stably supplied. An extruder is preferred.

  The biomass raw material 8 supplied into the gasification chamber 12 is decomposed and gasified in the gasification region 9. At this time, a gas decomposition residue is generated at the bottom of the gasification chamber 12, and this gas decomposition residue is introduced into the combustion chamber 4 along with the heat medium 13a, and in the presence of an oxidant in the combustion chamber 4. It is completely burned and discharged as combustion gas 3 outside the gasification furnace 14a.

  On the other hand, the product gas resulting from the gasification of the biomass raw material 8 in the gasification chamber 12 passes through the heavy gas decomposition apparatus 7 provided in the upper part of the gasification chamber 12 and is taken out to the outside. As shown in FIG. 2, the heavy gas decomposition apparatus 7 includes containers 7 a to 7 g filled with a catalyst 23. Specific examples of the catalyst 23 include a Group VIII metal catalyst such as a nickel-based catalyst including nickel-supported lignite and nickel-supported alumina, or an iron-based catalyst including limonite.

  As nickel carrying | support lignite, the thing of average particle diameter of 0.5-3 mm and nickel carrying amount of 3-20 weight% can be used, for example. As lignite, for example, water 13%, fixed carbon 34%, volatile content 51%, ash content 2% can be used.

  As Ni carrying | support alumina, what has the average particle diameter and nickel carrying amount comparable as the above can be used, for example.

  Limonite is a loess in which water containing a lot of iron such as swamps and shallow seas is precipitated by exposure to the air, and is also called `` limonite '' or `` marsh iron ore '', and is commercially available as an adsorbent, Aged ones can be used.

  In the heavy gas decomposing apparatus 7, rectangular parallelepiped containers 7a to 7g filled with a catalyst 23 are arranged in a horizontal row, and the generated gas that has passed through the generated gas introduction path 18 is placed on the lower surface of each container 7a to 7g. A product gas inlet 20 to be introduced is provided. On the other hand, a generated gas discharge port 21 is provided on the upper surface of each of the containers 7a to 7g, and the generated gas discharged from the generated gas discharge port 21 passes through the generated gas discharge path 19 and is discharged to the outside. It has become.

  Each container 7a to 7g is provided with a detachable rail 22 on the upper surface portion, the lower surface portion, or both of them, and although not shown, the heavy gas decomposition apparatus 7 in the gasification chamber 12 is provided on the side. A groove into which the detachable rail 22 is fitted is formed, and the individual containers 7a to 7g can be easily attached and detached as necessary by sliding the detachable rail 22 with respect to the groove. . In the figure, the detachable rail 22 is provided only on the upper surfaces of the two containers 7d and 7e, but in reality, it is provided in all the containers 7a to 7g.

  When the heavy gas decomposing apparatus 7 having the containers 7a to 7g having the above configuration is used, it is inevitable that the catalyst 23 deteriorates with the decomposition reaction time. For example, one of the containers 7a to 7g A mode in which another container is used after the container is used until the catalyst 23 deteriorates, that is, a mode in which the generated gas is sequentially guided to the containers 7a to 7g, or the generated gas is sequentially supplied to an adjacent container at every elapse of a predetermined time. It is preferable to adopt a mode that leads to.

  The catalyst 23 that has deteriorated due to use can be regenerated while being filled in the containers 7a to 7g, and then incorporated into the operating gasification furnace 14a again. Therefore, the effect of the catalyst 23 can be utilized to the maximum, and a low-temperature operation for a long time is possible.

  By passing through the heavy gas decomposing apparatus 7, there is almost no heavy gas component such as benzene or naphthalene in the product gas. Therefore, the generated gas can be used effectively, and the tar-like substance does not adhere to the gas piping and equipment, so that the equipment maintenance is easy, the washing is not complicated, and the cost reduction is extremely effective.

  In this embodiment, since the heavy gas decomposition apparatus 7 is provided in the gasification chamber 12, the internal combustion heat generated by the combustion of the gas decomposition residue of the biomass raw material 8 moved from the gasification chamber 12 through the fluidized bed 13 is used. Then, thermal energy that sufficiently promotes decomposition or reforming of the heavy gas is supplied from the combustion chamber 4 to the heavy gas decomposition device 7 in the gasification chamber 12.

  Therefore, the internal combustion heat generated by the combustion of the gas decomposition residue of the biomass raw material 8 can cover the thermal energy necessary for the decomposition or reforming of the heavy gas, and the thermal efficiency is greatly improved. As a result, the apparatus can be downsized. It becomes possible.

  In particular, livestock excrement as the biomass raw material 8 generates a small amount of heavy gas and can be operated with a low load. And by using what was mentioned above as the catalyst 23, the heavy gas in the produced gas by gasification of livestock waste can be effectively decomposed and removed even at a low temperature of, for example, 500 to 700 ° C., so that significant energy saving is achieved. Is possible.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the type and flow rate of the gasifying agent and the oxidizing agent, or the form of the partition for adjusting the circulation and movement of the heat medium may be appropriately changed according to the target heat medium circulation design.

  Moreover, the heavy gas decomposition | disassembly apparatus 7 is not limited to the structure shown in FIG. 2, For example, the number of containers may be arbitrary numbers. Further, the shapes of the product gas inlet 20 and the product gas outlet 21 of the containers 7a to 7g are not limited to the elliptical shape as shown in the figure, and may be appropriately determined according to, for example, the flow rate of the product gas, the filling amount of the catalyst 23, and the like. Change to

  Further, the recovered heat 2 from the heat medium 13 a of the fluidized bed 13 may be used for the additional fuel 1.

  The apparatus of the present invention is a biomass raw material such as thinned wood, rice / straw, pruned branches, discarded agricultural products, waste seaweed, livestock waste and other agricultural waste, domestic waste such as household garbage and sewage sludge, It can be used for biomass recycling by gasification and decomposition of industrial sludge such as activated sludge, paper sludge, and coffee lees, especially livestock excreta with less tar generation compared to other waste Suitable for livestock waste.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.
<Example 1>
As raw material for biomass, composted pig manure with a water content of 25% by mass is supplied from the sample hopper through the sample supply feeder to the gasification chamber in the internal circulation type fluidized bed low-temperature contact gasifier at a supply rate of 1 kg / hr. Supplied.

  Similarly, a certain amount of water supplied from a water supply tank through a water supply pump into the gasification chamber was converted into water vapor by a superheated steam generator, and this was introduced as a gasifying agent at a supply rate of 9.3 g / min. .

  Moreover, the buffer tank was passed through the buffer tank from the air compressor unit, and air heated by the air preheater was introduced as an oxidizing agent at a supply rate of 23 l / min.

  On the other hand, a constant amount of foundry sand is filled as a heat medium through the fluid medium hopper from the fluid medium hopper through the fluid circulation bed type low temperature contact gasification furnace, and the pyrolysis temperature is controlled to about 650 ° C. for continuous operation. Went.

  The combustion gas discharged from the combustion chamber was passed through a cyclone, further condensed water was removed by a water condenser, and the gas was passed through a gas meter for discharge.

  The gas generated in the gasification chamber is discharged out of the furnace as a product gas through a heavy gas cracking unit filled with a lignite nickel-based catalyst installed in the gasification chamber, and the condensed water is removed by a water condenser and passed through a gas meter. Then, a certain amount was introduced into a sampling line and collected in a gas bag for gas composition analysis, and the product gas other than that for sampling was burned by a combustion apparatus and then exhausted outside.

  All operating conditions can be monitored by a computer connected to the control panel.

  The size of the furnace was a furnace length of 1,250 mm and a furnace width of 412 mm, and an extremely compact one was used. The use of additional fuel and heat recovery were not performed in this example.

  As a result, continuous operation for 180 minutes was possible under the above-described conditions. The product gas composition was 31 to 36% hydrogen, 5 to 12% carbon monoxide, 1 to 4% methane, and 17 to 21% carbon dioxide, and it was confirmed that an effective product gas was generated.

  It was also found that the furnace can be processed with 1 kg / hr composted pig manure while being compact. Furthermore, it was found that tar generation in the furnace and piping was small.

It is a mimetic diagram showing composition of an internal circulation type fluidized bed type low-temperature contact gasification furnace device in one embodiment of the present invention. It is a perspective view which shows the principal part structure of a heavy gas decomposition | disassembly apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Additional fuel 2 Recovery heat 3 Combustion gas 4 Combustion chamber 5 Oxidation area | region 6 Product gas 7 Heavy gas decomposition device 7a-7g Container 8 Biomass raw material 9 Gasification area | region 10 Gasification agent supply port 11a-11e Oxidant supply port 12 Gas Gasification chamber 13 Fluidized bed 13a Heat medium 14 Internal circulation type fluidized bed low temperature contact gasifier apparatus 14a Gasifier 15 Partition 16 Partition 17 Partition partition 18 Product gas introduction channel 19 Product gas discharge channel 20 Product gas introduction port 21 Product gas Discharge port 22 Detachable rail 23 Catalyst

Claims (6)

  An internal circulation type fluidized bed low-temperature contact gasification furnace apparatus for gasifying and cracking biomass raw material, comprising a fluidized bed composed of a flowable heat medium laid in the gasification furnace, and a heat medium below Gasification in which biomass raw material is gasified in the presence of a gasifying agent, a partition wall whose lower end is embedded in the fluidized bed so that it can be circulated through the side and one chamber partitioned by the partition wall And a combustion chamber that burns the gas decomposition residue of the biomass raw material that has moved from the gasification chamber through the fluidized bed in the presence of an oxidant, and is the other chamber partitioned by the partition wall. An internal circulation type flow characterized in that a heavy gas decomposition device filled with a catalyst for promoting decomposition or reforming of heavy gas in the produced gas by gasification of biomass raw material is provided in the chemical conversion chamber Bed cold contact gasification furnace apparatus.   The gasifying agent supply port for supplying a gasifying agent to the fluidized bed at the bottom of the gasification chamber and an oxidant supplying port for supplying an oxidizing agent to the fluidized bed at the bottom of the combustion chamber are provided. Internal circulation type fluidized bed low temperature contact gasifier.   At least one partition wall for adjusting the circulating movement of the heat medium, the lower end of which is embedded in the fluidized bed so that the heat medium can be circulated through the lower side, and the heat medium can be circulated through the upper side. 3. The internal circulation type according to claim 1, further comprising at least one of the partition wall and the at least one partition wall configured to adjust the circulation movement of the heat medium. Fluidized bed type low temperature contact gasifier.   The catalyst charged in the heavy gas decomposition apparatus is a nickel-based catalyst including nickel-supported lignite and nickel-supported alumina, or a Group VIII metal-based catalyst such as an iron-based catalyst including limonite. Item 4. The internal circulation type fluidized bed low-temperature contact gasifier apparatus according to any one of Items 1 to 3.   A livestock excrement is supplied as a biomass raw material to the internal circulation type fluidized bed low-temperature contact gasification furnace apparatus according to any one of claims 1 to 4, and the livestock excrement is gasified in a gasification chamber, and a gas produced by gasification is generated. A method for gasifying and decomposing livestock excreta, comprising introducing into a heavy gas decomposition apparatus and decomposing or reforming a heavy gas in a product gas.   The livestock excrement according to claim 5, wherein the gasification temperature of the livestock waste in the gasification chamber and the decomposition or reforming temperature of the heavy gas in the heavy gas decomposition apparatus are in the range of 500 to 700 ° C. Gasification decomposition method.

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