JPH1081885A - Method and equipment for convering organic waste material into valuable material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for converting organic waste material into valuable material wherein various problems due to the incineration and disposal of organic waste material are solved while low-cost H2 is produced and used for the synthesis of NH3 . SOLUTION: This method comprises subjecting organic waste material to two-step gasification 24, 25 to give a gas, converting the gas through a CO conversion 27 into H2 , and using the H2 as a raw material for the synthesis of NH3 . Examples of the organic waste material that can be used include municipal refuse, solidified fuels, waste biomass, low grade coals, and waste oils. The gasification comprises a combination of a primary gasification 24 with a secondary gasification 25, wherein a fluidized bed oven is used for the primary gasification while a molten bed oven is used for the secondary gasification. The fluidized bed over serves to gasify the organic waste material at 450-700 deg.C in the fluidized bed part and at 600-900 deg.C in the free board part. The molten bed oven serves to gasify char and tar and melt ash to form a slag by high- temperature burning at 1,200-1,500 deg.C so that the ash in slag form can be discharged from the bottom of the oven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the recycling of organic wastes, and more particularly to municipal solid waste, waste plastics and waste F.
RP, biomass waste, automobile waste, low-grade coal,
Gasification and combustion of waste oil and fuel substitutes etc. solidified or slurried of these, discharge metals and ash contained in the waste in a recyclable state, and obtain CO and CO obtained by the recovered gas. The present invention relates to a method and an apparatus for recycling organic waste, which uses H ₂ -containing gas as a raw material for NH ₃ (ammonia) synthesis. The above-mentioned fuel substitutes are called RDF (solidified fuel), which is obtained by crushing and sorting municipal solid waste, adding quicklime, etc., and compression-molding the municipal solid waste. Includes oily slurry fuels. FRP is a fiber reinforced plastic, and waste biomass includes water and sewage waste (contaminants, sewage, sewage sludge, etc.), agricultural waste (rice husk, rice straw, surplus products, etc.), forest waste (no Waste, bark, thinned wood, etc.), industrial waste (pulp chips, dust, etc.), and construction waste. Low-grade coal includes peat with a low degree of coalification, or waste produced during coal cleaning. In addition, the present invention is applicable to oil shale, kitchen garbage, corpses of beasts, waste clothing, paper waste, and any other organic matter.

[0002]

2. Description of the Related Art NH ₃ (ammonia) is a basic raw material in the chemical industry which is mass-produced as a raw material for nitric acid, various fertilizers (ammonium, ammonium sulfate, urea), acrylonitrile, caprolactam and the like. NH ₃ is synthesized from N ₂ and H ₂ under high pressure using a catalyst. H ₂ is formed by steam reforming such as natural gas and naphtha, or partial combustion of hydrocarbons such as petroleum, coal and petroleum coke. It has been obtained by gasification. On the other hand, municipal solid waste, waste plastic, waste FR
Organic waste typified by P, biomass waste, and automobile waste has been reduced in volume by incineration or has been landfilled untreated. Both directly and indirectly, the amount of these recycled is very small overall. H ₂ , a raw material of NH ₃ , is made from natural gas, naphtha, petroleum, coal, petroleum coke, etc. Most of these are imported from overseas. You have lost your competitive edge. For this reason, there has been a long-felt desire for raw materials that are inexpensive and can be procured locally.

[0003] On the other hand, incineration of solid waste also has the following problems and problems. Up to now, stoker furnaces and fluidized bed furnaces have been used for incineration treatment.
This has created disadvantages for energy recycling. That is, the air ratio during combustion is high, so the amount of exhaust gas is large, harmful dioxins are contained in the exhaust gas, the metals discharged from the furnace are not suitable for recycling because they are oxidized, and ash landfill This is the bottom of the land. The number of places to install volume reduction facilities such as ash melting facilities has recently been increasing, but this has resulted in an increase in the construction and operating costs of the entire waste disposal system. Furthermore, recently, there has been an increasing desire to make the most of the energy of solid waste. If solid waste is dumped on land without being treated, it becomes difficult to secure a dumping place and it is no longer acceptable for environmental protection. As a result, scrapped shredder dust and the like became extremely difficult to dispose of.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and not only recovers resources in waste by establishing a utilization method, but also opens a route for separation and reuse. The degree of combustion is adjusted to an incomplete state to generate a synthesis gas having a preferable composition as a raw material of the NH ₃ synthesis raw material, to solve various problems associated with incineration and dumping of organic waste, and to obtain inexpensive H ₂ . Another object of the present invention is to provide a method and an apparatus for recycling organic waste used for NH ₃ synthesis and the like.

[0005]

In order to solve the above-mentioned problems, in the present invention, an organic waste is obtained by obtaining a synthesis gas mainly composed of H ₂ · CO by two-stage decomposition gasification. A method of recycling organic waste, characterized in that the obtained H ₂ is used as a raw material for synthesizing NH ₃ . Further, the present invention relates to the decomposition gasification step, wherein (a) a primary gasification step of partially burning organic waste, and (b) a partial combustion of gas, char and tar from the primary gasification step at a higher temperature. And (c) a gas cooling step of bringing the gas from the secondary gasification step into direct contact with cooling water.
(C) a method for recycling organic waste.

The organic waste in the above method uses at least one of municipal solid waste, solidified fuel, slurry fuel, waste plastic, waste FRP, biomass waste, automobile waste, low-grade coal, and waste oil. be able to. A solid fuel such as coal and / or oil coke can be added to the organic waste as an auxiliary material depending on the properties to be used. The gasification combustion is a combination of a primary gasification step and a higher temperature secondary gasification step, and it is preferable to use a fluidized bed furnace for the primary gasification step and a melting furnace for the secondary gasification step. Fluidized bed furnace used in the primary gasification step,
Fluidized bed part is 450-700 ° C, free board part is 600
It is maintained at ９００900 ° C. to perform partial combustion of the supplied waste. From the furnace bottom, metals such as iron, copper and aluminum in the waste are recovered in an unoxidized and clean state. The melting furnace used in the secondary gasification step burns partially the gas containing the char and tar supplied from the gasification furnace at a high temperature of 1200 to 1500 ° C., converts the ash into molten slag, and discharges it from the furnace bottom. I do. At this time, if the smelting furnace is a swirling melting furnace, high-load combustion becomes possible, and due to the centrifugal force accompanying the swirling flow, the char contained in the gas was blown to the furnace wall and formed on the wall surface. It is burned over time in the slag phase. In this manner, since the char can be completely burned, a device or the like for reburning the char is not required. This is another feature of the present invention, and performing the gasification and slagging simultaneously in parallel is a very effective resource-saving measure. Therefore, it is preferable to employ a rotary melting furnace as the melting furnace.

Further, in the gasification, a mixed gas of O ₂ and steam obtained by air separation is used as a gasifying agent for H ₂ production, while N 2 obtained by air separation is used.
₂ is for NH ₃ synthesis. Cryogenic separation method PS for air separation
A, an adsorption method such as a TSA method, a method using a separation (rich activity) membrane, and the like can be applied. Further, a mixed gas in which the composition ratio of H ₂ and N ₂ is 3: 1 is obtained by using oxygen-enriched air as the gasifying agent, and this mixed gas can be used as it is for NH ₃ synthesis. Further, in the present invention, a fluidized bed gasifier for partially burning organic waste, a melting furnace for partially burning gas from the fluidized bed gas at a high temperature, and cooling the gas from the melting furnace An apparatus for recycling organic waste, characterized by having a quenching chamber.

In the resource recycling apparatus, a scrubber for removing harmful gases such as HCl in the entrained gas and dust is disposed downstream of the quenching chamber, and then CO and H ₂ O in the gas are converted to H ₂ and CO ₂ . Provide a CO converter to convert
It is preferable to provide an acid gas removing device for removing CO ₂ and H ₂ O after O conversion and a reactor for synthesizing NH ₃ by reacting purified H ₂ and N ₂ . Further, in the organic waste recycling apparatus, an air separator for separating N ₂ and O ₂ is separately provided, and the separated N ₂ is used as the NH 4.
_{(3) It is} preferable to provide means for introducing into the synthesis reactor and means for introducing the separated O ₂ into the fluidized-bed gasification furnace and / or the melting furnace.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS At present, a "gasification and melting system" is under development as a new environmental protection type waste treatment technology which can replace incineration treatment, and the present invention also uses this system. The features when this gasification and melting system is used for incineration of waste are shown. Since the gas combustion replaces the conventional solid combustion, a low air ratio combustion of about 1.3 is realized, and as a result, the amount of exhaust gas is significantly reduced. The dioxins and their precursors in the exhaust gas are almost completely decomposed by the high-temperature combustion. Ash in the waste is collected as harmless slag.
Therefore, the life of the landfill can be prolonged, and it can be used for roadbed materials and the like. Since the functions of dioxin decomposition and ash melting are incorporated in the system, the entire apparatus is made compact, and the construction cost is lower than adding each function to a conventional incinerator. Significant reduction of exhaust gas volume also leads to cost reduction of exhaust gas treatment equipment.

[0010] Because the energy of gas, char, and tar generated in the gasifier can be effectively used for melting ash, electric power and the like required when dedicated equipment for melting ash is not required, and the operating cost can be kept low. It is easy to make a high efficiency power generation type flow. Metals such as iron, copper, and aluminum can be recovered in a recyclable, unoxidized and clean state. Although air is used as an O ₂ source in a normal incineration process, a fuel gas can be recovered by replacing it with pure O ₂ or oxygen-enriched air. The present invention provides a process in which a gasification and melting system is integrated with an NH ₃ production facility, and includes solid waste such as municipal solid waste, waste plastic, waste FRP, biomass waste, and automobile waste, and low-grade coal,
By collectively gasifying waste oil, various problems associated with incineration and dumping are solved, and the waste itself is effectively used.

In order to gasify organic wastes, it is preferable to use a gasification and melting system in which a fluidized bed gasification furnace and a melting furnace are combined. In a fluidized bed gasifier, sand (silica sand, olivine sand, etc.), alumina, iron powder, limestone, dolomite, etc. are used as a fluidizing medium. Among organic wastes, municipal waste, biomass waste, plastic waste, automobile waste, and the like are roughly crushed to about 30 cm. Solid fuel and slurry fuel are used as they are. 40 for low-grade coal
Crush coarsely to less than mm. These are divided and received in a plurality of pits, and after being sufficiently stirred and mixed in each pit, they are supplied to a gasification furnace as appropriate. Of course, the supply to the gasification furnace may be performed separately from each pit or may be performed by mixing. In addition, depending on the properties of the waste to be gasified (calorific value and moisture), coal, oil coke, or the like is added as an auxiliary material as needed. The amount to be added is appropriately set depending on the properties of the waste.

[0012] The organic waste is supplied to a gasification furnace, and is heated at 450 to 700 ° C in a fluidized bed portion and 600 to 700 ° C in a free board portion.
Perform primary gasification at ~ 900 ° C. Further, secondary gasification is performed at 1200 to 1500 ° C. in a subsequent melting furnace. For the primary and secondary gasification reactions, a mixed gas of O ₂ and H ₂ O or O ₂ alone is used after preheating as necessary as a gasifying agent. Therefore, the amount of heat required for gasification at each stage is obtained by partial combustion of the raw material. Gas, tar, and char are generated by gasification in the fluidized bed, but the lower the temperature, the higher the rate of tar and char generation and the lower the gas generation rate. On the other hand, among the metals contained in the waste, those having a melting point higher than the fluidized bed temperature are discharged from the bottom of the gasifier together with the fluidized medium. Therefore, for example, in order to recover aluminum, the fluidized bed temperature should be lower than 660 ° C., which is the melting point of aluminum.

In the free board section of the gasifier, 600 to 9
Although gasification is performed at 00 ° C., a considerable amount of undecomposed tar and char still remains. Freeboard gasification reduced the load on the melting furnace and increased the gasification rate, making it possible to reduce the size of the melting furnace. In addition, the capacity of the freeboard portion of the gasifier can be effectively used for gasification. However, freeboard gasification is not essential. In the latter melting furnace, the tar and char are completely decomposed by the secondary gasification at 1200 to 1500 ° C., and the generated gas is a gas composed of H ₂ , CO, CO ₂ , N ₂ , and H ₂ O. The molten slag ash is continuously discharged from the furnace bottom of the melting furnace and then granulated to be used as aggregate and other materials for civil engineering and building materials.

[0014] The fluidized bed temperature of the gasifier is 450 ° C to 700 ° C.
The reason why the temperature is set to ° C is as follows. FIG.
2 shows the thermal decomposition characteristics of the sample in a nitrogen atmosphere. In the primary gasification process, it is desirable to reduce the amount of gas components of waste and gas and tar components as much as possible and to reduce the solid components composed of combustibles and ash. For solid component chars, small-particle chars are transported to the melting furnace on the rising airflow in the gasifier, but large-particle chars that are not pulverized in the fluidized bed are discharged from the furnace together with incombustibles. Is done. When the ratio of solid components is large, the amount discharged from the furnace must be increased in order to prevent accumulation in the fluidized bed. The discharged char is reused after removing sand and incombustibles, but the amount is preferably small. As shown in FIG. 4, the lower the thermal decomposition temperature, the more solid components are generated. In addition, when the temperature is lower than 450 ° C., the thermal decomposition rate becomes extremely slow, and the operation becomes difficult because undecomposed substances are deposited on the fluidized bed. Conversely, as the temperature increases, the proportion of the solid component decreases, which is advantageous for gasification. However, waste is introduced into the gasification furnace as near as possible without crushing, so if the temperature becomes too high,
The reaction speed increases. For this reason, the fluctuation of the amount accompanying the supply of the waste causes the fluctuation of the gas generation amount and the furnace internal pressure, and adversely affects the operation of the subsequent melting furnace. For example, according to a gasification and melting test using scrap car shredder dust, if the gasification temperature is set to 650 ° C. or less, CO in exhaust gas is reduced to 10 ppm.
It turned out that it can be suppressed below. In addition, many wastes contain metals, and it is an important theme to collect and recycle these metals without being oxidized. Among metals, recovery of aluminum is important, but since the melting point of aluminum is 660 ° C., the gasification temperature must be lower than this. Therefore, the upper limit temperature of gasification is 660
It is preferable that the temperature be in the range of 650 to 650 ° C.

Usually, when producing synthesis gas for a chemical industrial raw material, gasification is performed under a pressure of 10 to 40 atm.
Gasification is performed at normal pressure, and gas purification after CO conversion is 30 ~
It is considered as a practical method to perform the process under a pressure of 40 atm. As the gasifying agent used in the gasification furnace, H ₂ O is usually mixed with pure O ₂ obtained by cryogenically separating air, but CO ₂ recovered in the acid gas removing step may be mixed. . Similarly, N ₂ obtained by cryogenic separation of air is used directly as a raw material for NH ₃ synthesis. Alternatively, a method using O ₂ -enriched air as a gasifying agent is also conceivable. O ₂
If the composition ratio of H ₂ and N ₂ after CO conversion is adjusted to 3: 1 by adjusting the concentration, the raw material gas for NH ₃ synthesis can be used as it is. However, there is a disadvantage that the size of the equipment for gas processing increases because the gas flow rate increases. As described above, when waste is used as a raw material for synthesizing NH ₃ , there is a problem that the amount of waste is secured or the quality is stabilized. Another problem is how to deal with changes in waste quality during operation.

In order to solve such a problem by a practical method, in the case where stable operation using only waste is difficult or when starting up the plast, the present invention uses high calorie such as coal or oil coke as waste. in properties stable of, yet it may be used in combination solid fuel proven in H ₂ production. That is, it is possible to stabilize the quantity and quality of the gasification raw material by blending coal or oil coke so as to be about 20 to 40% of the whole. During the operation, if the quality of waste decreases for some reason and the concentration of H ₂ or CO in the product gas decreases, the properties of the product gas are stabilized by increasing the supply ratio of the solid fuel. I can do it. In addition, the coal used here is
It is not a low-rank coal belonging to waste, but rather a sub-bituminous coal and a bituminous coal class with a high degree of coalification.

Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a configuration diagram of a gasification and melting system used for incineration of ordinary waste. In the figure, 1 is a hopper, 2 is a fixed-quantity feeding device, 3 is a fluidized bed gasifier, 4 is a fluidized bed, 5 is a free board, 6 is a burner, 7 is a trommel,
8 is a bucket conveyor, 9 is a rotary melting furnace, 10 is a primary combustion chamber, 11 is a secondary combustion chamber, 12 is a slag separation section, 13
Is a burner. a is organic waste, b is air (for fluidized bed), b 'is air (for freeboard), b "is air (for melting furnace), c is coarse incombustible, d is silica sand, and e is generated gas ,
e 'is combustion exhaust gas, and f is slag.

Organic waste a previously crushed as required
Is supplied to a fluidized-bed gasification furnace 3 using a screw-type quantitative supply device 2 after being supplied to a hopper 1. Air b is fed from below the fluidized bed gasifier 3 as a gasifying agent, and a fluidized bed 4 of silica sand is formed on the dispersion plate. The organic waste a is charged above the fluidized bed 4 and 450 to 70
In contact with O ₂ in air in a fluidized bed 4 maintained at 0 ° C.,
It is quickly gasified by pyrolysis. The fluidized medium is discharged from the bottom of the gasification furnace 3 together with the incombustibles, and the coarse incombustibles c are removed by the trommel 7. The separated silica sand d is transported upward by the bucket conveyor 8 and returned to the fluidized bed gasification furnace 3. Metals are contained in the coarse incombustibles c,
Practically, by setting the fluidized bed temperature to 500 to 600 ° C., iron, copper, and aluminum can be recovered in an unoxidized and clean state.

The organic waste a charged into the fluidized bed 4 is
It becomes gas, tar and carbide by pyrolysis gasification. The gas and tar vaporize and rise in the furnace. The carbide is finely pulverized by the disturbing motion of the fluidized bed 4 to form char. Because the char is porous and light, it is entrained in the upward flow of product gas. The use of hard silica sand as the fluid medium facilitates the grinding of carbides. Air b 'is blown into the free boat 5, and gasification is performed again at 600 to 900C. In this way, gas components are reduced in molecular weight and decomposition of tar and char proceeds. The generated gas e discharged from the furnace top is supplied to the primary combustion chamber 10 of the swirling melting furnace 9 and burns at a high speed of 1200 to 1500 ° C. while mixing with the preheated air b ″ in the swirling flow. Is completed in the secondary combustion chamber 11, and the combustion exhaust gas e 'is discharged from the slag separation section 12. The ash contained in the char accompanying the high-temperature combustion becomes slag mist, and the ash content of the primary combustion chamber 10 is increased by the centrifugal force of the swirling flow. It is trapped by the molten slag phase on the furnace wall, flows down the furnace wall, enters the secondary combustion chamber 11, and flows down from the bottom of the slag separation section 12. The primary combustion chamber 10 and the secondary combustion chamber 10 of the swirling melting furnace 9 Burners 13 for raising the temperature are installed one by one in the combustion chamber 11.
Low air combustion of about 1.3 and melting of ash into slag are achieved.

FIG. 2 is another block diagram of the gasification and melting system used in the present invention, which is used for producing a synthesis gas of 10 to 40 atm. In the figure, the same reference numerals as those in FIG. 1 have the same meanings, 14 and 14 'are lock hoppers, 15 and 15' are screens, 16 is a fluid medium circulation line, 17 is a rotary melting furnace (integrated type), and 18 is High temperature gasification room, 19 is quenching room,
20 is a cyclone, 21 is a gas scrubber, and 22 is a settler. Incidentally, a 'coal or oil coke for supplementary fuel, g and g' is the gasifying agent comprising a mixed gas of O ₂ and H ₂ O, g "is O _2. Pre crushed organic waste a is supplied quantitatively to the fluidized bed gasifier 3 through a lock hopper or the like (not shown), and from below the fluidized bed gasifier 3, a mixture of O ₂ and H ₂ O is used as a gasifying agent g. Then, the fluidized bed 4 of silica sand is formed on the dispersion plate 4. The organic waste a is introduced above the fluidized bed 4, and is 450-700.
It contacts with the gasifying agent g in the fluidized bed 4 maintained at a temperature of 10 ° C. and a pressure of 10 to 40 atm, and is rapidly gasified by pyrolysis. The fluidized medium is discharged from the bottom of the fluidized-bed gasification furnace 3 together with the incombustibles, passes through the lock hopper 14, and the coarse incombustibles c are removed by the screen 15. The silica sand d under the sieve is transported upward by a fluidized medium circulation line 16 constituted by a bucket conveyor or the like, and returned to the fluidized bed gasification furnace 3. Although metals are contained in the coarse incombustibles c, iron, copper and aluminum can be recovered in an unoxidized and clean state by setting the fluidized bed temperature to 500 to 600 ° C. in practice.

The gasification in the fluidized bed 4 causes gas, tar,
Carbides are formed. The gas and tar vaporize and rise in the furnace. The carbide is finely pulverized by the disturbing motion of the fluidized bed 4 to form char. Because the char is porous and light, it is entrained in the upward flow of product gas. The use of hard silica sand as the fluid medium facilitates the grinding of carbides. The free boat 5 O ₂ and the H ₂ O gas agent g comprises a mixture of 'is blown, the gasification is carried out at 600 to 900 ° C.. In this way, gas components are reduced in molecular weight and decomposition of tar and char proceeds. The generated gas e ″ discharged from the furnace top is supplied to the high-temperature gasification chamber 18 of the swirling type melting furnace 17, and the preheated O ₂
Is burned and gasified at 1200 to 1500 ° C. by the gasifying agent g ″. The ash in the gas becomes slag mist due to high temperature and enters the quenching chamber 19 together with the gas. Is discharged to the outside via the lock hopper 14 ', and is separated by the screen 15' into coarse slag f 'and fine slag f ".

FIG. 3 shows NH from organic waste of the present invention.
FIG. 4 is an overall process diagram in the case of synthesizing ₃ . In the figure, 2
3 is air separation, 24 is primary gasification of organic waste, 25
The quenching of the secondary gasification and gas at a high temperature, 26 cooling the washing of the gas with water, 27 CO conversion, 28 acid gas removal by RECTISOL, 29 N ₂ cleaning, 30 ammonia synthesis, i is the air , J is O ₂ , k is N ₂ , l is NH ₃ ,
O indicates an acid gas + H ₂ O. The air i is separated into O ₂ j and N ₂ k by the air separation of 23, and the O ₂ j is used as a gasifying agent for converting the organic waste a into a primary gasifier 24 and a high-temperature secondary gasifier 24 and 25. 25. As the air separation means, a cryogenic separation method is usually used.

The organic waste a and the auxiliary raw material a 'are
The process up to gasification in step 5 and cooling of the generated synthesis gas is as described in FIG. Next, in the cooling / washing step 26, HCl and dust in the gas are removed, and a water scrubber is generally used for this.
On the other hand, the slag granulated from the step 25 is discharged.
27 is a CO conversion, cobalt CO and of H ₂ O in the gas -
It is converted to H ₂ and CO ₂ by a CO conversion reaction on a molybdenum-based low-temperature sulfur active catalyst. In addition, H ₂ O for CO conversion
Used for the quenching of 25 gases. Further, at 28, acid gas such as CO ₂ , H ₂ S (hydrogen sulfide) and COS (carbonyl sulfide) and H ₂ O are absorbed and removed by a rectizole method using low-temperature methanol as an absorbing liquid. Since the gas from 28 contains trace amounts of CO and CO _{2 which} are catalyst poisons for NH ₃ synthesis in 30, it is washed and removed with liquid nitrogen. This is the 29 N ₂ cleaning step.
The mixed gas of H ₂ and N ₂ thus compressed to about 220 atm is reacted under an iron catalyst to synthesize NH ₃ .

[0024]

According to the present invention, the following effects can be obtained. NH ₃ and H ₂ source such as synthetic, can be converted to procurable organic waste with inexpensive and their country. This gives N
It is substantially reduced the cost of production of H _3. The organic waste is gasified by the H _2,
Various problems associated with conventional incineration can be avoided. That is, exhaust gas disappears and no dioxins are generated.
In addition, since the ash in the waste becomes harmless slag, the life of the landfill can be extended, and the ash can be used for roadbed materials and the like.

Metals such as iron, copper, and aluminum contained in waste can be recovered without undergoing recyclable oxidation. In this way, from the standpoint of effective use of waste and environmental protection, a gasification facility for organic waste is constructed adjacent to the ammonia synthesis facility, and the two are organically connected from the viewpoint of raw material utilization, thus providing a total You can enjoy the benefits of the system. By supplementing the waste with a solid fuel such as coal or oil coke, it is possible to deal with the problem of fluctuation in the quality and quantity of the waste. In particular, when the quality of generated gas is deteriorated due to a decrease in the quality of waste, a stable operation can be realized by increasing the mixing ratio of the solid fuel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a gasification and melting system used in the present invention.

FIG. 2 is another configuration diagram of the gasification and melting system used in the present invention.

FIG. 3 is an overall process diagram in the case of synthesizing NH ₃ from the waste of the present invention.

FIG. 4 is a graph showing the thermal decomposition characteristics of RDF in an N ₂ atmosphere.

[Explanation of symbols]

1: hopper, 2: quantitative feeder, 3: fluidized bed gasifier, 4: fluidized bed, 5: free board, 6: burner, 7:
Trommel, 8: bucket conveyor, 9: revolving melting furnace, 10: primary combustion chamber, 11: secondary combustion chamber, 12: slag separation diagram, 13: burner, 14, 14 ': lock hopper, 15, 15': Screen, 16: Fluid medium circulation line, 17: Swirling melting furnace (integral type), 18: High temperature gasification chamber, 19: Quenching chamber, 20: Cyclone, 21: Gas scrubber, 22: Settler, 23: Air separation, 24: primary gasification, 25: secondary gasification, 26: cooling and washing, 27:
CO conversion, 28: acid gas removal, 29: N ₂ wash 3
0: ammonia synthesis a: organic waste, a ': coal or oil coke,
b: air (for fluidized bed), b ': air (for freeboard), b ": air (for melting furnace), c: coarse incombustible, d:
Silica sand, e, e ", e '", e "": generated gas, e': flue gas, f: slag, f ': coarse slag, f ": fine slag, g, g': gasifying agent ( A mixed gas of O ₂ and H ₂ O), g ″: O ₂ , i: air, j: O ₂ , k: N ₂ ,
l: NH ₃ , m: H ₂ O, n: fuel gas, O: acid gas + H ₂ O

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akisaku Fujinami 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. (72) Inventor Kazuo Takano 111-1 Haneda Asahicho, Ota-ku, Tokyo Stock (72) Inventor Masaaki Irie 11-1 Haneda Asahicho, Ota-ku, Tokyo Ebara Corporation (72) Inventor Tetsuhisa Hirose 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Ebara Corporation (72) Inventor Shuichi Nagato 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Takahiro 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside the Ebara Corporation ( 72) Inventor Toshio Fukuda 2-3-1 Higashishinagawa, Shinagawa-ku, Tokyo UBE Building Ube Industries, Ltd.

Claims (11)

[Claims] 1. CO and H ₂ O in a gas obtained by gasifying an organic waste are converted into H ₂ by a CO conversion reaction, and the H ₂ is supplied to an NH ₃ synthesis raw material, and incombustible substances are removed. A method for recycling organic waste, comprising recovering as slag. 2. A (a) primary gasification step of partially burning organic waste, and (b) a gas, a char, and a tar from the primary gasification step are further gasified by partial combustion at a higher temperature, and ash content is further reduced. A secondary gasification process to turn the molten slag into
The method for recycling organic waste according to claim 1, further comprising the steps (a) to (c) of (c) a gas cooling step of rapidly cooling the gas from the secondary gasification step. 3. The primary and / or secondary gasification step,
3. The method for recycling organic waste according to claim 2, wherein the method proceeds under a pressure of 10 to 40 atm. Wherein the primary and / or secondary gasification step, as a gasifying agent, after separation of the air into the gas containing no N ₂ and N ₂ in gas separation step, using a gas which does not contain the N ₂ The method according to claim 2, wherein the organic waste is recycled. 5. The method according to claim 1, wherein a solid fuel such as coal and / or oil coke is added to the organic waste as an auxiliary material. 6. The method for recycling organic waste according to claim 2, wherein a fluidized bed furnace is used in the primary gasification step, and a melting furnace is used in the secondary gasification step. 7. The fluidized bed furnace used in the primary gasification step has a fluidized bed section at 450 to 700 ° C. and a freeboard section at 6 ° C.
7. The method for recycling organic waste according to claim 6, wherein the temperature is set to 00 to 900 [deg.] C., and metals such as iron, copper and aluminum in the waste are recovered from the furnace bottom in an unoxidized and clean state. 8. The melting furnace used in the secondary gasification step,
7. The method for recycling organic waste according to claim 6, wherein the temperature is set to 1200 to 1500 [deg.] C., and the ash is converted into molten slag and discharged from the furnace bottom. NH ₃ Synthesis of 9. claim 1, wherein the resulting H _2, recycling method of organic waste, characterized in that is reacted with N ₂ in the presence of a catalyst to obtain the NH _3. 10. A fluidized-bed gasifier for partially burning organic waste, a melting furnace for partially burning gas from the fluidized-bed gasifier at a high temperature, and quenching for rapidly cooling gas from the melting furnace. Chamber, cleaning scrubber for removing harmful gas and dust in gas, CO converter for converting CO and H ₂ O in gas to H ₂ and CO ₂ , and removing CO ₂ and H ₂ O in gas An apparatus for recycling organic waste, comprising: an acid gas removing device that performs the reaction; and a reactor that synthesizes NH ₃ by reacting the purified H ₂ and N ₂ . 11. The resource recycling apparatus according to claim 10, further comprising an air separator for separating N ₂ and O ₂ , and means for introducing the separated N ₂ into the NH ₃ synthesis reactor. Means for introducing separated O ₂ into the fluidized bed gasification furnace and / or the melting furnace.