JP6777110B2 - Pyrolysis method and equipment for organic substances - Google Patents

Description

The present invention relates to a technique for thermally decomposing an organic substance such as waste plastic to thermally decompose it into a gaseous substance or the like.

At present, most of waste plastics, oil-containing sludge, waste oil, etc. are incinerated. However, the incineration process has a high environmental load such as CO ₂ generation, and there is also a problem of thermal damage to the incinerator, so establishment of chemical recycling technology is required.
Among the chemical recycling technologies, various technologies for converting organic substances into gas fuels and liquid fuels have been studied conventionally, mainly for waste plastics, and for example, the following proposals have been made.

According to Patent Document 1, a coke oven gas (COG) having a hydrogen concentration of 60 vol% or more, preferably 80 vol% or more, and a temperature of 600 ° C. or more is reacted with an organic substance such as waste plastic to hydrogenate the organic substance with high efficiency. A method of decomposing and gasifying to increase the heat of COG is disclosed.
Further, in Patent Document 2, an exhaust gas containing carbon monoxide and hydrogen generated in a gasification melting furnace is used, and excess steam is added to the exhaust gas to cause a shift reaction, and the shift reaction generated gas is used. A method of modifying an organic substance to reduce its molecular weight (pyrolysis) by contacting it with an organic substance is disclosed.

Further, in Patent Document 3, carbon monoxide-containing exhaust gas generated in a metallurgical reactor is used, excess steam is added to the exhaust gas to cause a shift reaction, and the shift reaction-generated gas is brought into contact with an organic substance. By allowing the organic substance to be reformed to reduce the molecular weight (pyrolysis), the liquid product among the low molecular weight products (pyrolysis products) emitted from the reforming reactor is modified into the reforming reactor. Disclosed is a method in which the gasification rate is improved by refluxing to the water and rethermally decomposing it.

JP-A-2007-224206 Japanese Patent No. 5679088 Japanese Unexamined Patent Publication No. 2013-173884

However, the above-mentioned prior art has the following problems.
First, Patent Document 1 is characterized in that the gasification rate of organic substances is extremely high, but the hydrogen concentration in COG is 60 vol% or more only in the final carbonization process of the coal carbonization process. In the method of Patent Document 1, it is necessary to switch the gas flow path at the timing of the final carbonization stage and supply COG of 600 ° C. or higher containing a large amount of dust to the hydrocracking reactor of waste plastic. However, under such harsh conditions, it is difficult to keep the flow path switching valve operating stably for a long period of time, and in this sense, it can be said that the technology is not feasible. Furthermore, in order to efficiently gasify waste plastic, it is necessary to continuously supply COG containing 60 vol% or more of hydrogen to the hydrocracking reactor. For this purpose, each carbonization chamber It is necessary to install a hydrogen concentration meter and a flow path switching valve in the facility, which increases the equipment cost.

Further, the method of Patent Document 2 has advantages that it is easy to carry out and the equipment cost can be reduced because the reaction is carried out under relatively mild conditions in terms of equipment, but the obtained thermal decomposition product is oily. There is a problem that the proportion of the substance increases and the yield of the gaseous substance is low. When considering transportation to the place of use, oily substances have poor handleability, such as the need for heat retention in order to maintain viscosity. Therefore, in the thermal decomposition of organic substances, it is desired to increase the yield of gaseous substances as much as possible.

In response to such a problem, in the method of Patent Document 3, in order to increase the yield of the gas product, the liquid product among the pyrolysis products produced from the reforming reactor is refluxed to the reforming reactor. However, when the present inventors conducted a verification experiment, most of the liquid product volatilized even if the liquid product was refluxed to the reforming reactor as in the method of Patent Document 3. It was found that the thermal decomposition did not proceed only by itself, and it was recovered as a substance that became liquid again at room temperature.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and when an organic substance such as waste plastic is thermally decomposed to obtain a thermal decomposition product, a gas product (thermal decomposition which is a gas at room temperature) is obtained. It is an object of the present invention to provide a method for thermally decomposing an organic substance capable of increasing the yield of a product). Another object of the present invention is to provide equipment suitable for carrying out such a method for thermally decomposing an organic substance.

As a result of repeated studies to solve the above problems, the present inventors recirculate the liquid product among the thermal decomposition products taken out from the reactor to the reactor in the fluidized layer type reactor. When performing thermal decomposition, a gas product (thermal decomposition product that is a gas at room temperature) is produced by blowing the liquid product directly into the fluidized layer through a blowing pipe installed through the side wall of the reactor. It can be efficiently thermally decomposed into a gas, which can increase the yield of a gas product (thermal decomposition product which is a gas at room temperature), and in particular, a mixed gas introduced into a reactor as a fluidized gas. It has been found that the yield of a gas product (thermal decomposition product which is a gas at room temperature) can be dramatically increased by blowing a part of the gas product together with the liquid product into the fluidized layer through a blowing pipe.

The present invention has been made based on such findings, and has the following gist.
[1] In a fluidized bed type reactor (A) into which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, an organic substance is thermally decomposed by contacting with the mixed gas (g). It's a method
Of the pyrolysis products of organic substances taken out from the reactor (A), at least a part of the pyrolysis product (x) which is liquid at room temperature is in a liquid state, and the side wall portion of the reactor (A). A method for thermally decomposing an organic substance, which comprises blowing into a fluidized bed (f) through a blowing pipe (C) installed so as to penetrate the reactor and thermally decomposing it in a reactor (A).
[2] In the thermal decomposition method of the above [1], a part of the mixed gas (g) introduced into the reactor (A) as a fluidized gas is blown into a blow pipe (x) together with a liquid thermal decomposition product (x). A method for thermally decomposing an organic substance, which comprises blowing into the fluidized bed (f) through C).

[3] In the thermal decomposition method of the above [2], the blow pipe (C) has a single pipe structure or a double pipe structure composed of an inner pipe and an outer pipe, and has a single pipe structure. In the case of, the mixed gas (g) and the liquid thermal decomposition product (x) are blown from a single pipe in a mixed state, and in the case of a blow pipe (C) having a double pipe structure, the inner pipe and the outer pipe are blown. A method for thermally decomposing an organic substance, which comprises blowing a mixed gas (g) from one of the pipes and a liquid thermal decomposition product (x) from the other.
[4] In the thermal decomposition method of [2] or [3] above, the superficial velocity in the reactor in the region above the installation height of the blow pipe (C) is u ₀ (m / sec), and the lower part. Assuming that the superficial velocity in the reactor in the region on the side is u ^* (m / sec), the flow velocity u _L (m / m /) of the mixed gas (g) blown into the reactor (A) through the blowing pipe (C). A method for thermally decomposing an organic substance, which comprises controlling sec) so as to satisfy the following equations (1) and (2).
u _L ≧ u ₀ … (1)
u ^* ≧ u ₀ /2… (2)

[5] In any of the above-mentioned [1] to [4], the organic substance is one or more selected from waste plastic, oil-containing sludge, waste oil, and biomass. Pyrolysis method.
[6] The method for thermally decomposing an organic substance according to any one of the above [1] to [5], wherein the mixed gas (g) further contains water vapor.
[7] In the thermal decomposition method of the above [6], the mixed gas (g) is characterized in that the water vapor concentration is 20 to 70 vol%, the hydrogen concentration is 10 to 40 vol%, and the carbon dioxide concentration is 10 to 40 vol%. Pyrolysis method of organic substances.
[8] A method for producing a gaseous substance, which comprises recovering a pyrolysis product that is a gas at room temperature as a useful gaseous substance, which is produced by the thermal decomposition method according to any one of the above [1] to [7]. ..

[9] A fluidized bed reactor in which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, and a reaction in which an organic substance is thermally decomposed by contacting with the mixed gas (g). Vessel (A) and
The reactor (A) discharged from the gas containing pyrolysis products of the organic substance (g _p) and cooled to room temperature or ambient temperature near the thermal decomposition products of organic substances contained in the gas (g _p) a separation device by liquefying a portion separated from the gas (g _{p) (B),}
The reactor (A) is installed through the side wall portion of the separation device (B) in a fluidized bed at least a portion of the gas (g _p) thermal decomposition products of the liquid separated from the (x) (f) the A pyrolysis facility for organic substances, which comprises a blowing pipe (C) for blowing into.
[10] In the thermal decomposition equipment of the above [9], the separation device (B) is a thermal decomposition equipment composed of a sprinkling type device.
Further, a water removing device (D) for removing water from the liquid thermal decomposition product (x) separated by the separating device (B) and a liquid thermal decomposition in which the water is removed by the water removing device (D). A pyrolysis facility for organic substances, which comprises a supply means (E) for supplying at least a part of a product (x) to a blow pipe (C).

[11] In the pyrolysis facility of [9] or [10] above, a part of the mixed gas (g) introduced into the reactor (A) as a fluidized gas is further supplied to the blow pipe (C). The mixed gas (g) having the supply means (F) and supplied to the blow pipe (C) by the supply means (F) is contained in the fluidized bed (f) together with the liquid pyrolysis product (x). A pyrolysis facility for organic substances, which is characterized by being blown into it.
[12] In the thermal decomposition equipment of the above [11], the blow pipe (C) has a single pipe structure or a double pipe structure composed of an inner pipe and an outer pipe, and has a single pipe structure. In the case of, the mixed gas (g) and the liquid thermal decomposition product (x) are blown from the single pipe in a mixed state, and in the case of the blow pipe (C) having a double pipe structure, the inner pipe A thermal decomposition facility for organic substances, characterized in that a mixed gas (g) is blown from one of the outer pipes and a liquid thermal decomposition product (x) is blown from the other.

According to the present invention, when an organic substance such as waste plastic is thermally decomposed to obtain a thermal decomposition product, the yield of a gas product (thermal decomposition product which is a gas at room temperature) can be effectively increased. it can. In addition, as for the implementation equipment, no special measuring instrument or flow path switching valve is required, and organic substances can be thermally decomposed even at a relatively low reaction temperature, so it can be implemented with relatively simple equipment. it can. In addition, the gas used for pyrolysis may be a gas that can be stably supplied at a steel mill or a waste treatment plant, and such a gas can be used to efficiently pyrolyze an organic substance to produce a gas product (gas product). It is possible to obtain a pyrolysis product having a high proportion of the pyrolysis product) which is a gas at room temperature.

Overall configuration diagram schematically showing a flow of a thermal decomposition method for an organic substance according to the present invention and an embodiment of a thermal decomposition facility. In pyrolysis equipment of FIG. 1, a gas (g _p) comprising a thermal decomposition product of the organic materials are cooled to room temperature or ambient temperature near a portion of the thermal decomposition products of organic substances contained in the gas (g _p) diagram showing by liquefying separation device B to separate from the gas (g _p) schematically (longitudinal sectional view) A block diagram (longitudinal sectional view) schematically showing a moisture removing device D for separating liquid thermal decomposition products and moisture in the thermal decomposition equipment of FIG. 1. In the present invention, a block diagram (longitudinal cross-sectional view) schematically showing various embodiments of a blowing pipe C for blowing a liquid pyrolysis product into the reactor A. In the present invention, through the reactor superficial velocity u ₀ in the region above the installation height of the blow pipe C, the reactor superficial velocity u ^* in the region below, and the blow pipe C. explanatory view showing a flow rate u _L of the mixed gas blown into the reactor a (g)

In the method of the present invention, in a fluidized bed type reactor A in which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, an organic substance is thermally decomposed by contacting with the mixed gas (g). In the method, of the pyrolysis products of the organic substance taken out from the reactor A, at least a part of the pyrolysis product (x) which is liquid at room temperature is in a liquid state, and the side wall of the reactor A. It is blown into the fluidized bed f through a blowing pipe C installed so as to penetrate the portion, and is thermally decomposed in the reactor A. Further, preferably, a part of the mixed gas (g) introduced into the reactor A as a fluidized gas is blown into the fluidized bed f together with the liquid pyrolysis product (x) through the blowing pipe C. .. In the following description, among the pyrolysis products of organic substances, the pyrolysis product (x) which is liquid at room temperature is referred to as "oily substance", and the pyrolysis product which is gas at room temperature is referred to as "gaseous substance". That is.

As described above, among the pyrolysis products taken out from the reactor A, when the oily substance is refluxed to the reactor A for rethermal decomposition, it is directly blown into the fluidized bed f through the blowing pipe C. By pyrolyzing, the oily substance can be efficiently thermally decomposed into a gaseous substance, whereby the yield of the gaseous substance can be increased. Further, in particular, a part of the mixed gas (g) introduced into the reactor A as a fluidized gas is blown into the fluidized bed f together with the oily substance through the blowing pipe C, thereby dramatically increasing the yield of the gaseous substance. Can be enhanced.

As the mixed gas (g) containing at least hydrogen and carbon dioxide used for the thermal decomposition of the organic substance in the present invention, for example, a gas generated in a gasification melting furnace or an ironmaking process, or a modified gas thereof is used. Can be used. That is, if the gas generated in the gasification melting furnace or the steelmaking process satisfies the predetermined gas composition, it can be used as it is, but for example, a gas rich in carbon monoxide and low in hydrogen such as a linz-Donaw gas is used. In this case, excess water vapor may be added to carry out the shift reaction. As a result, a mixed gas containing hydrogen originally contained, carbon dioxide and hydrogen generated in the shift reaction, and water vapor not consumed in the shift reaction is generated, and the gas composition suitable for thermal decomposition of organic substances is obtained. can do.

Here, the gasification melting furnace is a furnace facility that thermally decomposes waste by heating it in a low oxygen state, burns or recovers the gas generated by this thermal decomposition, and melts ash and incombustibles at a high temperature. There is a method in which thermal decomposition and melting are performed integrally, and a method in which thermal decomposition and melting are performed separately. Specifically, gasification reforming method (for example, thermoselect method), shaft furnace method (for example, coke bed type, oxygen type, plasma type, etc.), kiln furnace method, fluidized bed method, semi-dry distillation / negative pressure There is a combustion method and so on. In the present invention, the exhaust gas generated in any type of gasification and melting furnace may be used, or a mixture of two or more types of exhaust gas may be used. The exhaust gas generated in the gasification melting furnace includes, for example, an exhaust gas containing carbon dioxide and hydrogen having a carbon dioxide concentration of 20 to 60 vol% and a hydrogen concentration of 60 to 20 vol%, and an exhaust gas having a carbon monoxide concentration of 10 to 50 vol%. Exhaust gas containing carbon monoxide and hydrogen having a hydrogen concentration of 50 to 10 vol% can be mentioned, and these exhaust gases are reformed as they are or to a predetermined gas composition, and then a mixed gas (g) for thermal decomposition of organic substances is used. ) Can be used.
In addition, linz-Donaw gas and blast furnace gas in the iron-making process are also usable gases, and in the case of gas lacking hydrogen as described above, hydrogen is generated by the so-called shift reaction, so the hydrogen concentration is about 10 vol%. However, the composition is suitable for the mixed gas (g) of the present invention.

It is generally known that high molecular weight organic substances such as waste plastics start thermal decomposition when heated at 300 to 400 ° C. or higher, but at this time, they become lighter and heavier. When hydrogen coexists during thermal decomposition, the hydrogenation reaction to the hydrocarbon species and the hydrocracking reaction proceed, which is effective in suppressing heaviness and reducing the molecular weight. However, there is a problem that high temperature is required for hydrocracking and hydrogen consumption is high.

On the other hand, steam reforming and carbon dioxide reforming can be regarded as the oxidation of hydrocarbons by oxygen in H 2 _O and CO ₂ molecules, low molecular weight carbonaceous product inhibition achieved with a small amount of hydrogen addition it can. Further, steam reforming and carbon dioxide reforming are characterized in that the reaction temperature decreases as the carbon chain of the organic molecule to be reformed becomes longer. By combining these hydrogenation, hydrocracking, steam reforming, and carbon dioxide reforming, it is possible to efficiently promote the reduction of molecular weight of organic substances even at a relatively low reaction temperature.
Therefore, the mixed gas (g) used in the present invention preferably contains water vapor in addition to hydrogen and carbon dioxide.

When an organic substance used in the present invention a hydrocarbon (C m _{H n),} the above reaction can be represented by the reaction formula shown below.
Hydrogenation: C _m H _n + H ₂ → C _m H _{n + 2}
Hydrogenation decomposition: C _m H _n + H ₂ → C _p H _q + C _r H _s (m = p + r, n + 2 = q + s)
Steam reforming: C _m H _n + H ₂ O → C _m-1 H _n-2 + CO + 2H ₂
Carbon dioxide reforming: C _m H _n + CO ₂ → C _m-1 H _n-2 + 2CO + H ₂
However, hydrogenation also includes the following CO and CO ₂ metanation reactions.
CO + 3H ₂ → CH ₄ + H ₂ O, CO ₂ + 4H ₂ → CH ₄ + 2H ₂ O
The above hydrogenation and hydrocracking also proceed with H ₂ generated by steam reforming and carbon dioxide gas reforming.

Further, if water vapor is added to the gas containing carbon monoxide and the shift reaction of (i) below is carried out, CO can be converted into H ₂ and CO _2, which is suitable as the mixed gas (g) used in the present invention. It will be something like that.
CO + H ₂ O → H ₂ + CO ₂ … (i)
Since some exhaust gas generated in gasification and melting furnaces and gas generated in steelworks contain a large amount of carbon monoxide, according to this method, thermal decomposition is performed by controlling the shift reaction between carbon monoxide and steam. A mixed gas suitable for use can be obtained.

In particular, if steam is excessively added to the exhaust gas containing carbon monoxide, steam remains in the produced gas, so that the steam reforming reaction can be utilized. That is, by appropriately controlling the reaction rate of the shift reaction, the concentrations of steam, hydrogen, and carbon dioxide in the gas can be controlled to obtain a mixed gas (g) having a gas composition suitable for thermal decomposition of organic substances. ..
The reaction rate of the shift reaction can be controlled by adjusting the residence time in the shift reactor. For example, in order to shorten the residence time, it is common to reduce the shift reactor length or the catalyst filling amount, in which case the shift reactor length and the catalyst filling amount are almost in equilibrium. It may be about 1/2 to 1/4 of the case where the reaction is allowed to proceed.

The exhaust gas generated from the thermoselect type gasification melting furnace usually contains about ₂₀ to 40 vol% of CO, 40 to 20 vol% of CO ₂ , and ₂₀ to 40 vol% of H ₂ . Therefore, by simply mixing an appropriate amount of water vapor with the exhaust gas containing carbon dioxide and hydrogen, CO: 15 to 20 vol%, CO ₂ : 10 to 35 vol%, H ₂ : 15 to ₂₀ vol%, H ₂ O: The composition is about 20 to 50 vol%, which is suitable as a mixed gas (g) for thermal decomposition of organic substances.
Further, the blast furnace gas and the linz-Donaw gas generated in the steelworks can be reformed to a gas composition suitable for thermal decomposition of organic substances by utilizing the same shift reaction.
When a gas generated by the shift reaction as described above is used as the mixed gas (g), if the organic substance to be charged into the reactor A contains water, water vapor is generated in the reactor A. Therefore, it is preferable to adjust the excess ratio of water vapor added in the shift reaction in consideration of the amount.

In the present invention, the organic substance to be thermally decomposed is not particularly limited, but a high molecular weight organic substance is preferable, and examples thereof include waste plastic, oil-containing sludge, waste oil, and biomass, and one of them. The above can be targeted.
There are no particular restrictions on the types of waste plastics to be targeted, but examples thereof include industrial waste systems and plastics subject to the Containers and Packaging Recycling Law. More specifically, polyolefins such as PE and PP, thermoplastic polyesters such as PA and PET, elastomers such as PS, thermosetting resins, synthetic rubbers and styrofoam can be mentioned. Inorganic substances such as fillers are added to many plastics, but in the present invention, such inorganic substances are not involved in the reaction and are discharged from the reactor A as a solid residue. Further, the waste plastic is pre-cut to an appropriate size as needed, and then put into the reactor A.

Further, if the waste plastic contains a chlorine-containing resin such as polyvinyl chloride, chlorine is generated in the reactor A, and this chlorine may be contained in a gaseous substance or an oily substance. Therefore, when there is a possibility that the waste plastic contains a chlorine-containing resin, a chlorine absorber such as CaO is added into the reactor A so that it is not contained in the gaseous substance or the oily substance in which chlorine is generated. Is preferable.

The oil-containing sludge is a sludge-like mixture generated in the oil-containing waste liquid treatment step, and generally contains about 30 to 70% by mass of water. Examples of the oil content in the sludge include, but are not limited to, various mineral oils, natural and / or synthetic fats and oils, and various fatty acid esters. In addition, in order to improve the handleability when supplying oil-containing sludge to the reactor A, the water content in the sludge may be reduced to about 30 to 50% by mass by a method such as centrifugation.

Examples of waste oil include, but are not limited to, various used mineral oils, natural and / or synthetic fats and oils, and various fatty acid esters. Further, it may be a mixture of these two or more kinds of waste oils. In addition, waste oil generated in the rolling process of a steel mill generally contains a large amount of water (usually more than 80% by mass), but this water is also reduced in advance by a method such as specific gravity separation. It is advantageous in terms of handleability.

Biomass includes, for example, sewage sludge, paper, wood (construction waste, thinned wood, etc.), agricultural waste (for example, paddy husks, tea husks, coffee husks (slag), etc.), and solid waste fuel (RDF). Processed biomass such as, but is not limited to these. Since biomass usually contains a large amount of water, it is preferable to dry it in advance from the viewpoint of energy efficiency. Further, in the case of biomass containing alkali metals such as sodium and potassium at a relatively high concentration, alkali metals may precipitate in the reactor A, so the alkali metals should be eluted in advance by a method such as washing with water. Is preferable. Large-scale biomass such as construction waste is cut in advance and put into the reactor A.

The reaction temperature in the reactor A is preferably about 400 to 800 ° C, more preferably about 600 to 700 ° C. If the reaction temperature is less than 400 ° C., the thermal decomposition of the organic substance is difficult to proceed, and the yield of the gaseous substance becomes low. On the other hand, when the reaction temperature exceeds 800 ° C., the thermal decomposition of the C1 to C4 compounds among the gaseous substances of the thermal decomposition products proceeds to generate CO and CO ₂ , the calorific value of the gaseous substances decreases, and the gaseous fuel The value as is reduced.
When the reaction temperature is high, the amount of gaseous substances produced tends to increase and the amount of oily substances produced tends to decrease, but the lower the reaction temperature, the lower the energy cost, so the reaction at as low a temperature as possible is advantageous. Is. Since the influence of pressure is hardly observed, it is economical to operate the reactor A with a slight pressure of about normal pressure to several kg / cm ² .

In the present invention, as the reactor A, a fluidized bed type reactor capable of thermally decomposing an organic substance at a high thermal decomposition rate because of its excellent heat conduction is used, and the reactor is charged into the fluidized bed type reactor A. The organic substance is thermally decomposed by contacting it with the mixed gas (g). Then, in order to increase the yield of the gaseous substance when at least a part of the oily substance is returned to the reactor A among the thermal decomposition products of the organic substance taken out from the reactor A, the side wall portion of the reactor A The oily substance is blown into the fluidized bed f through the blow pipe C installed through the above. The oily substance refluxed to the reactor A may be a part or all of the oily substance taken out from the reactor A.

The oily substance taken out from the reactor A is usually composed of C10 to C12 as a main component and C5 to C24 hydrocarbons, and consists of naphtha (C5 to C8), kerosene (C9 to C12), and light oil (C13 to C24). It is a high-quality light oil that is a mixture and contains almost no heavy oil equivalent (C25 or higher). Therefore, it is possible to recover it as it is and use it as a liquid fuel or the like, but from the viewpoint of transportation convenience and combustibility, it is desirable to increase the yield of the gaseous substance.

When a thermal decomposition experiment of an organic substance was carried out using a mixed gas (g) as described above at a reaction temperature of 400 to 800 ° C., the yield of the gaseous substance was about 30 to 40%, and the oily substance. The yield was about 60 to 70%. When the oily substance was analyzed, it was a hydrocarbon containing C10 to C12 as a main component. It is estimated that the organic substance, which is a polymer, undergoes thermal decomposition in the reactor, volatilizes when decomposed to about C10 to C12, is discharged to the outside of the reactor, and becomes an oily substance when cooled to room temperature. .. Even if this oily substance is dropped from the upper part of the reactor and refluxed, it is hardly thermally decomposed and volatilized, and becomes an oily substance again at room temperature. Therefore, a small amount of reflux does not lead to an improvement in the yield of gaseous substances. It was found that it is necessary to reflux (circulate) a large amount of oily substance in order to improve the yield.

Therefore, when the oily substance recovered from the reactor A was blown into the fluidized bed f through the blowing pipe C installed through the side wall portion of the reactor A and returned to the reactor A, the oily substance was released. It was thermally decomposed and the yield of the gaseous substance could be improved. This is because when an oily substance of about C10 to C12 is recirculated to the reactor as it is, the chain structure of carbon is cut and volatilizes before the molecular weight is reduced, whereas the fluidized bed f of the reactor A By injecting directly into the reactor A, the residence time in the reactor A becomes longer, and the chain structure of carbon is cut before volatilization to become a gaseous substance, and as a result, the gaseous substances of C1 to C4 are collected. It is thought that the rate will improve.
That is, when the oily substance is directly refluxed into the fluidized bed f of the reactor A and heated, the contact with the fluidized medium is good, and the oily substance and the volatilized oily substance are thermally decomposed when they come into contact with each other. It is considered that the yield of the gaseous substance is improved because of the progress of.

Further, when the oily substance is blown into the fluidized bed f through the blowing pipe C, a part of the mixed gas (g) introduced into the reactor A as a fluidized gas is supplied to the blowing pipe C, and this mixed gas is supplied. By blowing (g) into the fluidized bed f together with the oily substance, (i) the oily substance and the mixed gas (g) which is a gasifying agent are supplied into the fluidized bed f in close proximity, (ii). ) By blowing the oily substance together with the mixed gas (g), it becomes easy to diffuse in the fluidized bed f, so that the thermal decomposition of the oily substance in the fluidized bed f occurs efficiently, and the yield of the gaseous substance increases. It can be dramatically enhanced.

1 to 3 schematically show a flow of a method for thermally decomposing an organic substance according to the present invention and an embodiment of a pyrolysis facility. FIG. 1 is an overall configuration diagram, and FIG. 2 is a separation in FIG. A configuration diagram (longitudinal cross-sectional view) schematically showing the device B, and FIG. 3 is a configuration diagram (longitudinal cross-sectional view) schematically showing the moisture removing device D in FIG.
The pyrolysis facility of this embodiment is a fluidized bed type reactor in which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, and an organic substance is brought into contact with the mixed gas (g). a reactor a to pyrolysis, the reactor a was discharged from cooling the gas (g _p) comprising a thermal decomposition product of the organic substance down to room temperature or ambient temperature near, contained in the gas (g _p) by some of the thermal decomposition products of the organic material by liquefying and separating unit B for separating from the gas (g _p), is placed through the side wall of the reactor a, the gas (g _p) in the separation device B A blow pipe C for blowing at least a part of the separated liquid pyrolysis product (x) (oily substance) into the fluidized bed f is provided. Further, in this embodiment, a water removing device D that removes water from the oily substance separated by the watering type separating device B and at least a part of the oily substance from which the water is removed by the water removing device D are blown. A supply means F (gas) that has a supply means E (oil return pipe 11) for supplying to the pipe C and supplies a part of the mixed gas (g) introduced into the reactor A as a fluidized gas to the blow pipe C. A branch pipe 17) is provided.

The flow medium constituting the fluidized bed f is filled on the dispersion plate 1 in the fluidized bed type reactor A (pyrolysis furnace). A mixed gas (g) is introduced as a fluidized gas through the gas supply pipe 3 into the air box 2 below the dispersion plate 1, and the mixed gas (g) is blown out from the dispersion plate 1 to form a fluidized bed in a fluidized medium. f is formed. A supply pipe 4 for an organic substance is connected to the upper part of the reactor A, and the organic substance cut out from the storage tank 5 by the quantitative cutting device 6 is quantitatively supplied into the reactor A through the supply pipe 4. .. The supply pipe 4 is provided with a valve mechanism or the like for preventing the gas in the reactor A from flowing out to the storage tank 5.

The reactor A is heated by the heater 7 in order to raise the temperature to the reaction temperature and to compensate for the endothermic reaction accompanying gasification. The type of heating means of the reactor A is arbitrary. For example, a part of the flow medium is taken out of the reactor A and heated in a heating furnace such as a kiln, and the heated flow medium is recombined with the reactor. A circulating heating system that returns to the inside of A may be used.
A fixed amount of the organic substance is supplied through the supply pipe 4 into the reactor A which has been heated to a predetermined temperature and the fluidized bed f is formed, and the thermal decomposition of the organic substance is started. The reactor thermal decomposition products of organic substances produced in the A (gaseous substances and gasified oil) gas containing (g _p) is withdrawn from the reactor A with a gas take-out pipe 8, the separator B Sent. Note that the gas (g _p) being removed from the reactor A, typically include unreacted gas components of the mixed gas (g).

The oily substance is separated from the gas in the separation device B, but the separation device B of the present embodiment is composed of a sprinkling type as shown in FIG. In the separating apparatus B, by sprinkling the water supplied from the nozzle 13 by the water supply pipe 12 to the hot gas (g _p), temperature of the gas (g _p) it is cooled to about room temperature, the organic material thermally Of the decomposition products, the thermal decomposition products that are liquid at room temperature are liquefied into oily substances. In other words, oil is separated from the gas (g _p). The gas (gaseous substance) from which the oily substance is separated by the separation device B is transported to the outside of the system as a product gas by the gas transport pipe 9, and is used for various purposes.

On the other hand, the oily substance is sent to the water removing device D by the oil transport pipe 10, where the oily substance and the water are separated. The water removing device D of the present embodiment shown in FIG. 3 is provided with a specific gravity separation tank 14 for separating the water used for watering and the oily substance in the separation device B, and the oil content transport pipe 10 is provided in the specific gravity separation tank 14. Oily substances are supplied with water through. In the specific gravity separation tank 14, water having a large specific gravity sinks and an oily substance having a small specific gravity floats to separate oil and water. The oily substance floating in the specific gravity separation tank 14 overflows and is recovered, and the submerged water is extracted by the water recovery valve 15 and transported to a water treatment device (not shown) or the like through the water recovery pipe 16 as needed. Is reused in the separator B.

The oily substance overflowed from the specific gravity separation tank 14 and recovered is supplied to the blowing pipe C through the oil recirculation pipe 11 which is the supply means E, and is blown into the fluidized bed f of the reactor A from the blowing pipe C. However, in the present embodiment, a part of the mixed gas (g) is supplied to the blowing pipe C through the gas branch pipe 17 (supply means F) branched from the gas supply pipe 3, and both the oily substance flows from the blowing pipe C. It is blown into the layer f.
The blow pipe C is a lance type pipe body, and is installed so as to horizontally penetrate the side wall portion of the reactor A. In this blow tube C, the oily substance is sent to the central region of the reactor A (fluidized bed f) so that it is diffused throughout the fluidized bed f, so that the tip side thereof extends toward the center of the reactor A ( (Protruding). There is no particular limitation on the protrusion length of the blow pipe C, but if the protrusion length is too long, the blow pipe will be worn, the life of the blow pipe will be shortened, and if the protrusion length is too short, the reactor wall surface will be covered. Since deposits may accumulate, when the inner diameter of the reactor A is R and the protrusion length of the blow pipe C into the furnace is r, it is set to about 0.01 ≦ r / R ≦ 0.3. Is desirable.

One or more blow tubes C can be provided with respect to the reactor A, and when two or more are provided, it is preferable to provide them at appropriate intervals in the circumferential direction of the reactor A. When a plurality of blow pipes C are provided, for example, about 2 to 16 blow pipes C can be provided at substantially equal intervals in the circumferential direction of the reactor A.
Examples of the blow pipe C include (i) a pipe having a single pipe structure and blowing a mixed gas (g) and an oily substance from the single pipe in a mixed state, and (ii) a double pipe composed of an inner pipe and an outer pipe. It has a structure and can be used such that a mixed gas (g) is blown from one of the inner pipe and the outer pipe, and an oily substance is blown from the other pipe.

FIG. 4 is a configuration diagram (longitudinal sectional view) schematically showing various embodiments of such a blow pipe C. The blow pipe C shown in FIG. 4 (1) has a single pipe structure, and the oil recirculation pipe 11 and the gas branch pipe 17 are connected to the rear end of the single pipe 20, respectively, and the mixing supplied from the gas branch pipe 17 is provided. The gas (g) and the oily substance supplied from the oil recirculation pipe 11 are mixed in the pipe and blown into the fluidized bed f in a mixed state. Further, the blow pipe C shown in FIG. 4 (2) has a single pipe structure as in FIG. 4 (1), but since the inside of the reactor A has a high temperature atmosphere, it has a water-cooled structure to protect the lance. The cooling water supply pipe 18 is connected to the pipe body 23 provided with the cooling water flow path outside the single pipe 20.

Further, the blow pipe C shown in FIG. 4 (3) has a double pipe structure including an inner pipe 21 and an outer pipe 22, and a gas branch pipe 17 is provided at the rear end of the inner pipe 21 of the outer pipe 22. The oil return pipe 11 is connected to the rear end, and the mixed gas (g) supplied by the gas branch pipe 17 is from the tip of the inner pipe 21, and the oily substance supplied by the oil return pipe 11 is from the tip of the outer pipe 22. , Each of which is injected and is blown into the flow layer f in a state of being mixed at the tip of the blowing pipe C. Further, the blow pipe C shown in FIG. 4 (4) has a double pipe structure as in FIG. 4 (3), but has a water-cooled structure for lance protection, and the outer pipe 22 has a water-cooled structure. A pipe body 23 for a cooling water flow path is provided on the outside, and a cooling water supply pipe 18 is connected to the pipe body 23.
In the blow pipe C having the double pipe structure as shown in FIGS. 4 (3) and 4 (4), the mixed gas (g) is blown from the inner pipe 21 and the oily substance is blown from the outer pipe 22. You may.
When the oily substance is blown alone as shown in FIGS. 4 (3) and 4 (4), a liquid feeding pump (not shown) is used. Further, for example, when a gas is simultaneously blown into an oily substance as shown in FIGS. 4 (1) and 4 (2), a pump for liquid feeding (not shown) may be used, or an ejector action by the gas may be used. You may use it.

By blowing the oily substance together with the mixed gas (g) into the fluidized bed f from the blowing pipe C as in the present embodiment, (i) the oily substance and the mixed gas (g) which is a gasifying agent are in close proximity to each other. (Ii) The oily substance is blown into the fluidized bed f together with the mixed gas (g) so that it can be easily diffused in the fluidized bed f. Is efficiently generated, and the yield of gaseous substances is dramatically increased.

As a result of examining the flow velocity of the mixed gas (g) blown into the reactor A through the blow pipe C, the present inventors examined the superficial velocity in the reactor in the region above the installation height of the blow pipe C. When u ₀ (m / sec) and the superficial velocity in the reactor in the lower region is u ^* (m / sec), the mixed gas (g) blown into the reactor A through the blow pipe C It has been found that the flow velocity u _L (m / sec) is preferably controlled so as to satisfy the following equations (1) and (2), and the yield of the gaseous substance can be further improved.
u _L ≧ u ₀ … (1)
u ^* ≧ u ₀ /2… (2)

FIG. 5 shows the reactor superficial velocity u ₀ in the region above the installation height of the blow pipe C, the reactor superficial velocity u ^* in the region below the installation height, and the blow pipe C. The flow velocity u _L of the mixed gas (g) blown into the reactor A is shown.
When the flow velocity u _L of the mixed gas (g) introducing into the reactor A from the blowing tube C is too small, the concentration of oil in the (near blow tube tip without oil is not sufficiently diffused into the fluidized bed f The extremely high region is formed), the contact between the oily substance and the fluidized medium or the fluidized gas becomes insufficient, and as a result, the effect of improving the yield of the gaseous substance becomes small. Meanwhile, in order to increase the flow velocity u _L of the mixed gas to be introduced from the blowing duct C, it is necessary to increase the amount of gas branch pipe 17 (supply unit F) through a mixed gas supplied to the blow tube C (g) However, the amount of the mixed gas (g) introduced into the air box 2 of the reactor A is reduced accordingly, and the empty tower inside the reactor in the region below the installation height of the blow pipe C. The speed u ^* decreases. When the superficial velocity decreases, the momentum of the fluidized medium also decreases, so the fluidity of the fluidized bed (fluid medium) in the region below the installation height of the blow pipe C decreases, and the yield of gaseous substances also decreases. descend.

In order to avoid the above problems, it is possible to adjust the amount of the mixed gas (g) supplied to the blowing pipe C to optimize the flow velocity u _L of the mixed gas (g) blown from the blowing pipe C. preferable. That is, first, as in the above equation (1), the flow velocity u _L of the mixed gas (g) blown from the blow pipe C is set to the space inside the reactor in the region above the installation height of the blow pipe C. By setting the flow rate to u ₀ or more (ul _L ≧ u ₀ ), the oily substance can be sufficiently diffused into the fluidized bed f. Further, by blowing a part of the mixed gas (g) into the fluidized bed f through the blowing pipe C, the amount of the mixed gas (g) introduced into the air box 2 of the reactor A is reduced, and the blowing pipe is used. In order to prevent the fluidity in the region below the installation height of C from dropping excessively, the superficial velocity u ^* in the reactor in the region on the lower side is on the upper side as in Eq. (2) above. so that 1/2 or more of the reactor superficial velocity u ₀ at the region of the _{^{(u * ≧ u 0/2}} ), the flow velocity u _{L (blow} pipe of the mixed gas blown from the blow pipe C (g) The amount of mixed gas (g) blown from C) is controlled.
To control the flow rate u _L of the mixed gas (g), for example, the flow control valve to the gas branch pipe 17 (not shown) is provided to adjust the amount of gas supplied to the blow tube C.

As described above, when a part of the mixed gas (g) is blown from the blowing pipe C, the fluidity in the region lower than the installation height of the blowing pipe C decreases, so such a region is as much as possible. In order to make it smaller, it is preferable that the installation height (the height at which the oily substance is blown) at the side wall of the reactor A of the blow pipe C is as low as possible. Further, the lower the blowing height of the oily substance, the longer the residence time of the blown oily substance in the fluidized bed f and the higher the thermal decomposition efficiency. Therefore, from this point as well, the blowing pipe C It is preferable that the installation height is as low as possible. Specifically, as shown in FIG. 5, the installation height h of the blow pipe C (height from the upper surface of the dispersion plate) is 1 of the height H of the fluidized bed f (height from the upper surface of the dispersion plate). The position is preferably 1/2 or less.

The gaseous substance obtained by the method of the present invention is composed of carbon monoxide and hydrocarbons of about C1 to C4 as combustible components, and its LHV is about 4 to 8 Mcal / Nm ³ and has a high calorific value. Therefore, the gaseous substance obtained by the method of the present invention is suitable as a gaseous fuel, and can also be used as a reducing agent for a blast furnace or a coagulant for a sinter production process as a substitute for natural gas.

・ Invention Example 1
Gas generated from a refined thermoselect gasification and melting furnace (Thermoselect Waste Gasification and Reforming Process), and after removing impurities such as hydrogen chloride, water vapor is added to the exhaust gas (hereinafter referred to as "Purified synthesis gas"). Was used as a mixed gas (g) for thermal decomposition of organic substances. For this reason, a branch pipe is provided in the thermogas discharge pipe so that a part of the thermogas can be taken out through this branch pipe, and a flow control valve, a steam mixer, and a gas preheater are installed on the downstream side of this branch pipe. Placed.

The average composition of the thermogas was H ₂ : 31 vol%, CO: 33 vol%, CO ₂ : 30 vol%, H ₂ O: <1 vol%, N ₂ : 6 vol%. The thermogas was supplied to the steam mixer at 108 Nm ³ / hr, and steam at a pressure of 10 kg / cm ² G was supplied as steam at 64 Nm ³ / hr, and the temperature was raised to 430 ° C. with a preheater. The gas composition after mixing with water vapor is H ₂ : 20 vol%, CO: 21 vol%, CO ₂ : 19 vol%, H ₂ O: 37 vol%, N ₂ : 4 vol%, and the flow rate is 172 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and thermal decomposition treatment of waste plastic was carried out in the equipment configurations shown in FIGS. 1 to 3. Quartz sand was used as the fluid medium.

The reactor A has a cylindrical shape with an inner diameter of 1.2 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.
As the blowing pipe C, the one shown in FIG. 4 (3) was used so that the mixed gas (g) was blown from the inner pipe 21 and the oily substance was blown from the outer pipe 22. The inner pipe 21 constituting the blow pipe C has an inner diameter of 60 mm and an outer diameter of 62 mm, and the outer pipe 22 has an inner diameter of 80 mm. Twenty blow pipes C are installed at approximately equal intervals in the circumferential direction of the reactor A, and their installation height is 1/3 of the height of the fluidized bed f (height 1 m from the upper end of the dispersion plate). And said.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg of waste plastic crushed into particles as a model substance of waste plastic is used. It was supplied at / hr and the temperature was raised to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance separated by the separation device B was removed with the water removal device D, and then refluxed to the reactor A through the blow pipe C. The reaction state reached a steady state about 27 hours after the start of supply of waste plastic.

The flow velocity u _L of the mixed gas (g) blown into the reactor A from the inner pipe 21 of the blow pipe C is equal to or higher than the superficial velocity u ₀ (3.5 cm / s) in the reactor in the upper region 15 .2 cm / s, and the reactor superficial velocity u ^* (3.2 cm / s) in the lower region is 1 of the reactor superficial velocity u ₀ (3.5 cm / s) in the upper region. It was controlled to be / 2 or more.
The components of the gaseous substance passing through the gas transport pipe 9 were analyzed, and the LHV was determined. Further, the oily substance was extracted from the oil reflux pipe 11 for a certain period of time, and the amount of reflux of the oily substance was quantified. Table 1 shows the operating conditions in this invention example, and Table 2 shows the amount, composition, and LHV of the gaseous substance produced.

The total amount of thermogas, water vapor, waste plastic and oil adsorbent supplied as raw materials in the steady state was 1051 kg / hr, and the amount of gaseous substance produced was 988 kg / hr, so the yield was 94 mass%. The amount of reflux of the oily substance could be suppressed to a relatively small amount of 300 kg / hr. The LHV of the produced gaseous substance was 7.2 Mcal / Nm ³ , which was 4.0 times higher than that of the thermogas (1.8 Mcal / Nm ³ ).

-Invention Example 2
Water vapor was added to the gas generated from the converter of the steelworks to carry out a shift reaction, and the gas obtained by this was used as a mixed gas (g) for thermal decomposition of organic substances. For this reason, a branch pipe is provided in the linz-Donaw gas discharge pipe so that part of the linz-Donaw gas can be extracted through this branch pipe, and a flow control valve, steam mixer, etc. are located downstream of this branch pipe. A gas preheater and a shift reactor (cylindrical vertical type) filled with a Fe-Cr high-temperature shift catalyst were arranged.

The average composition of the linz-Donaw gas was H ₂ : 1 vol%, CO: 65 vol%, CO ₂ : 15 vol%, H ₂ O: 1 vol%, N ₂ : 18 vol%. Linz-Donaw gas was supplied to the steam mixer at 70 Nm ³ / hr, and steam at a pressure of 10 kg / cm ² G was supplied as steam at 101 Nm ³ / hr. The shift reaction was an exothermic reaction and the shift reactor temperature rose to 430 ° C. The gas composition after the shift reaction was H ₂ : 26 vol%, CO: 0 vol%, CO ₂ : 30 vol%, H ₂ O: 35 vol%, N ₂ : 9 vol%, and the flow rate was 171 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and thermal decomposition treatment of waste plastic was carried out in the equipment configurations shown in FIGS. 1 to 3. Quartz sand was used as the fluid medium.

The reactor A has a cylindrical shape with an inner diameter of 1.0 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.
As the blowing pipe C, the one shown in FIG. 4 (3) was used so that the mixed gas (g) was blown from the inner pipe 21 and the oily substance was blown from the outer pipe 22. The inner pipe 21 constituting the blow pipe C has an inner diameter of 100 mm and an outer diameter of 103 mm, and the outer pipe 22 has an inner diameter of 120 mm. Twenty-five blow pipes C are installed at approximately equal intervals in the circumferential direction of the reactor A, and their installation height is 1/3 of the height of the fluidized bed f (height 1 m from the upper end of the dispersion plate). And said.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg of waste plastic crushed into particles as a model substance of waste plastic is used. It was supplied at / hr and heated to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance separated by the separation device B was removed with the water removal device D, and then refluxed to the reactor A through the blow pipe C. The reaction state reached a steady state about 27 hours after the start of supply of waste plastic.

The flow velocity u _L of the mixed gas (g) blown into the reactor A from the inner pipe 21 of the blow pipe C is equal to or less than the superficial velocity u ₀ (5.0 cm / s) in the reactor in the upper region 4 .4 cm / s, and the reactor superficial velocity u ^* (4.6 cm / s) in the lower region is 1 of the reactor superficial velocity u ₀ (5.0 cm / s) in the upper region. It was controlled to be / 2 or more.
The components of the gaseous substance passing through the gas transport pipe 9 were analyzed, and the LHV was determined. Further, the oily substance was extracted from the oil reflux pipe 11 for a certain period of time, and the amount of reflux of the oily substance was quantified. Table 3 shows the operating conditions in this invention example, and Table 4 shows the amount, composition, and LHV of the gaseous substance produced.

The total amount of thermogas, water vapor, waste plastic and oil adsorbent supplied as raw materials in the steady state was 1051 kg / hr, and the amount of gaseous substance produced was 975 kg / hr, so the yield was 93 mass%. The amount of reflux of the oily substance could be suppressed to a relatively small amount of 302 kg / hr. The LHV of the produced gaseous substance was 5.7 Mcal / Nm ³ , which was 2.9 times higher than that of the linz-Donaw gas (2.0 Mcal / Nm ³ ).

・ Invention Example 3
Similar to Invention Example 1, a gas obtained by adding water vapor to thermogas was used as a mixed gas (g) for thermal decomposition of organic substances. For this reason, a branch pipe is provided in the thermogas discharge pipe so that a part of the thermogas can be taken out through this branch pipe, and a flow control valve, a steam mixer, and a gas preheater are installed on the downstream side of this branch pipe. Placed.

The average composition of the thermogas was H ₂ : 31 vol%, CO: 33 vol%, CO ₂ : 30 vol%, H ₂ O: <1 vol%, N ₂ : 6 vol%. The thermogas was supplied to the steam mixer at 108 Nm ³ / hr, and steam at a pressure of 10 kg / cm ² G was supplied as steam at 64 Nm ³ / hr, and the temperature was raised to 430 ° C. with a preheater. The gas composition after mixing with water vapor is H ₂ : 20 vol%, CO: 21 vol%, CO ₂ : 19 vol%, H ₂ O: 37 vol%, N ₂ : 4 vol%, and the flow rate is 172 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and thermal decomposition treatment of waste plastic was carried out in the equipment configurations shown in FIGS. 1 to 3. Quartz sand was used as the fluid medium.

The reactor A has a cylindrical shape with an inner diameter of 1.2 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.
As the blowing pipe C, the one shown in FIG. 4 (3) was used so that the mixed gas (g) was blown from the inner pipe 21 and the oily substance was blown from the outer pipe 22. The inner pipe 21 constituting the blow pipe C has an inner diameter of 100 mm and an outer diameter of 103 mm, and the outer pipe 22 has an inner diameter of 120 mm. Twenty blow pipes C are installed at approximately equal intervals in the circumferential direction of the reactor A, and their installation height is 1/3 of the height of the fluidized bed f (height 1 m from the upper end of the dispersion plate). And said.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg of waste plastic crushed into particles as a model substance of waste plastic is used. It was supplied at / hr and heated to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance separated by the separation device B was removed with the water removal device D, and then refluxed to the reactor A through the blow pipe C. The reaction state reached a steady state about 27 hours after the start of supply of waste plastic.

The flow velocity u _L of the mixed gas (g) blown into the reactor A from the inner pipe 21 of the blow pipe C is 51 cm, which is equal to or higher than the superficial velocity u ₀ (3.5 cm / s) in the reactor in the upper region. / S, and the reactor superficial velocity u ^* (1.2 cm / s) in the lower region is 1/2 of the reactor superficial velocity u ₀ (3.5 cm / s) in the upper region. It was controlled to be less than.
The components of the gaseous substance passing through the gas transport pipe 9 were analyzed, and the LHV was determined. Further, the oily substance was extracted from the oil reflux pipe 11 for a certain period of time, and the amount of reflux of the oily substance was quantified. Table 5 shows the operating conditions in this invention example, and Table 6 shows the amount of gaseous substance produced, the composition, and LHV.

The total amount of thermogas, water vapor, waste plastic and oil adsorbent supplied as raw materials in the steady state was 1051 kg / hr, and the amount of gaseous substance produced was 970 kg / hr, so the yield was 92 mass%. The amount of reflux of the oily substance could be suppressed to a relatively small amount of 307 kg / hr. The LHV of the produced gaseous substance was 7.2 Mcal / Nm ³ , which was four times as high as that of the thermogas (1.8 Mcal / Nm ³ ).

・ Invention Example 4
Similar to Invention Example 1, a gas obtained by adding water vapor to thermogas was used as a mixed gas (g) for thermal decomposition of organic substances. For this reason, a branch pipe is provided in the thermogas discharge pipe so that a part of the thermogas can be taken out through this branch pipe, and a flow control valve, a steam mixer, and a gas preheater are installed on the downstream side of this branch pipe. Placed.

The average composition of the thermogas was H ₂ : 31 vol%, CO: 33 vol%, CO ₂ : 30 vol%, H ₂ O: <1 vol%, N ₂ : 6 vol%. The thermogas was supplied to the steam mixer at 108 Nm ³ / hr, and steam at a pressure of 10 kg / cm ² G was supplied as steam at 64 Nm ³ / hr, and the temperature was raised to 430 ° C. with a preheater. The gas composition after mixing with water vapor is H ₂ : 20 vol%, CO: 21 vol%, CO ₂ : 19 vol%, H ₂ O: 37 vol%, N ₂ : 4 vol%, and the flow rate is 172 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and thermal decomposition treatment of waste plastic was carried out in the equipment configurations shown in FIGS. 1 to 3. Quartz sand was used as the fluid medium.

The reactor A has a cylindrical shape with an inner diameter of 0.8 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.
As the blowing pipe C, the one shown in FIG. 4 (3) was used, but contrary to Invention Examples 1 to 3, an oily substance was blown from the inner pipe 21 and a mixed gas (g) was blown from the outer pipe 22. I tried to get involved. The inner pipe 21 constituting the blow pipe C has an inner diameter of 32 mm and an outer diameter of 34 mm, and the outer pipe 22 has an inner diameter of 200 mm. Thirty blow pipes C are installed at approximately equal intervals in the circumferential direction of the reactor A, and their installation height is 1/3 of the height of the fluidized bed f (height 1 m from the upper end of the dispersion plate). And said.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg of waste plastic crushed into granules as a model substance of waste plastic is used. It was supplied at / hr and heated to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance separated by the separation device B was removed with the water removal device D, and then refluxed to the reactor A through the blow pipe C. The reaction state reached a steady state about 27 hours after the start of supply of waste plastic.

The flow velocity u _L of the mixed gas (g) blown into the reactor A from the outer pipe 22 of the blow pipe C is equal to or less than the superficial velocity u ₀ (7.7 cm / s) in the reactor in the upper region 7 .1 cm / s, and the reactor superficial velocity u ^* (3.6 cm / s) in the lower region is 1 of the reactor superficial velocity u ₀ (7.7 cm / s) in the upper region. It was controlled to be less than / 2.
The components of the gaseous substance passing through the gas transport pipe 9 were analyzed, and the LHV was determined. Further, the oily substance was extracted from the oil reflux pipe 11 for a certain period of time, and the amount of reflux of the oily substance was quantified. Table 7 shows the operating conditions in this invention example, and Table 8 shows the amount of gaseous substance produced, the composition, and the LHV.

The total amount of thermogas, water vapor, waste plastic and oil adsorbent supplied as raw materials in the steady state was 1051 kg / hr, and the amount of gaseous substance produced was 951 kg / hr, so the yield was 90 mass%. The amount of reflux of the oily substance could be suppressed to a relatively small amount of 310 kg / hr. The LHV of the produced gaseous substance was 7.2 Mcal / Nm ³ , which was four times as high as that of the thermogas (1.8 Mcal / Nm ³ ).

・ Comparative example 1
Similar to Invention Example 1, a gas obtained by adding water vapor to thermogas was used as a mixed gas (g) for thermal decomposition of organic substances. That is, the average composition of the thermogas used was H ₂ : 31 vol%, CO: 33 vol%, CO ₂ : 30 vol%, H ₂ O: <1 vol%, N ₂ : 6 vol%, and this thermo gas was used in the steam mixer. 108 Nm ³ / hr was introduced, steam at a pressure of 10 kg / cm ² G was supplied as steam at 64 Nm ³ / hr, and the temperature was raised to 430 ° C. with a preheater. The gas composition after mixing with water vapor is H ₂ : 20 vol%, CO: 21 vol%, CO ₂ : 19 vol%, H ₂ O: 37 vol%, N ₂ : 4 vol%, and the flow rate is 172 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and in the equipment configuration shown in FIG. 1, the thermal decomposition treatment of waste plastic was carried out without refluxing the oily substance to the reactor A. The reactor A has a cylindrical shape with an inner diameter of 0.8 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg / kg of waste plastic crushed into granules as a model substance of waste plastic. It was supplied at hr and heated to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance was not refluxed to the reactor A. The reaction state reached a steady state about 22 hours after the start of supply of waste plastic.

The amount and composition of the obtained gaseous substance and oily substance produced were determined by the same method as in Invention Example 1, and LHV was determined for the gaseous substance. Table 9 shows the raw material supply conditions in this comparative example, and Table 10 shows the amount of gaseous substance produced, the composition, and the LHV.
In this comparative example, the yield of the gaseous substance with respect to the total amount of raw materials supplied was as low as 33 mass%. The LHV of the produced gaseous substance was 7.2 Mcal / Nm ³ , which was 4.0 times higher than that of the thermogas.
As described above, in this comparative example, since the oily substance was refluxed to the reactor A and was not rethermally decomposed, the amount of gaseous substance produced was significantly reduced.

・ Comparative example 2
Similar to Invention Example 1, a gas obtained by adding water vapor to thermogas was used as a mixed gas (g) for thermal decomposition of organic substances. That is, the average composition of the thermogas used was H ₂ : 31 vol%, CO: 33 vol%, CO ₂ : 30 vol%, H ₂ O: <1 vol%, N ₂ : 6 vol%, and this thermo gas was used in the steam mixer. Steam of 108 Nm ³ / hr and a pressure of 10 kg / cm ² G as steam was supplied at 64 Nm ³ / hr, and the temperature was raised to 430 ° C. with a preheater. The gas composition after mixing with steam is H ₂ : 20 vol%, CO: 21 vol%, CO ₂ : 19 vol%, H ₂ O: 37 vol%, N ₂ : 4 vol%, and the flow rate is 172 Nm ³ / hr (mass flow rate). It was 171 kg / hr). This gas was used as a mixed gas (g) for thermal decomposition of organic substances, and thermal decomposition treatment of waste plastic was carried out in the equipment configurations shown in FIGS. 1 to 3. Quartz sand was used as the fluid medium.

The reactor A has a cylindrical shape with an inner diameter of 1.0 m (the diameter is constant in the height direction), and the height of the fluidized bed f in the reactor A (height from the upper end of the dispersion plate to the upper end of the fluidized bed) is It was set to 3 m.
As the blowing pipe C, the one shown in FIG. 4 (3) was used, and an oily substance was blown from the inner pipe 21 and nothing was blown from the outer pipe 22 (the entire amount of the mixed gas (g) was dispersed in the dispersion plate 1). Introduced into reactor A via The inner pipe 21 constituting the blow pipe C has an inner diameter of 32 mm and an outer diameter of 34 mm. Twenty blow pipes C were installed at substantially equal intervals in the circumferential direction of the reactor A, and the height of their installation exceeded the height of the fluidized bed f and was 3.5 m from the upper end of the dispersion plate. That is, in this comparative example, the oily substance was blown from the blowing pipe C not into the fluidized bed f but into the space above the fluidized bed f.

The fluidized bed type reactor A is preheated to 600 ° C. by the heater 7, and a mixed gas (g) is introduced into the reactor A, and 880 kg of waste plastic crushed into particles as a model substance of waste plastic is used. It was supplied at / hr and heated to the planned reaction temperature of 620 ° C. After reaching 620 ° C., the thermal decomposition treatment of the waste plastic was continued for 10 days. At this time, the oily substance separated by the separation device B was returned to the reactor A after removing the water content by the water removal device D. The reaction state reached a steady state about 27 hours after the start of supply of waste plastic.
The components of the gaseous substance passing through the gas transport pipe 9 were analyzed, and the LHV was determined. Further, the oily substance was extracted from the oil reflux pipe 11 for a certain period of time, and the amount of reflux of the oily substance was quantified. Table 11 shows the operating conditions in this invention example, and Table 12 shows the amount of gaseous substance produced, the composition, and the LHV.

In this comparative example, since the oily substance is refluxed to the upper part of the reactor A (the space above the fluidized bed f) without being blown into the fluidized bed f in the reactor A, almost the entire amount is treated as a gaseous substance. Although it was recovered, the amount of reflux of the oily substance was very large at 3500 kg / hr, and a large equipment burden (cost) was required for the reflux of the oily substance.

A Reactor B Separator C Blow-in pipe D Moisture removal device E Supply means F Supply means 1 Dispersion plate 2 Air box 3 Gas supply pipe 4 Supply pipe 5 Storage tank 6 Quantitative cutting device 7 Heater 8 Gas take-out pipe 9 Gas transport Pipe 10 Oil transport pipe 11 Oil recirculation pipe 12 Water supply pipe 13 Nozzle 14 Specific gravity separation tank 15 Water recovery valve 16 Water recovery pipe 17 Gas branch pipe 18 Cooling water supply pipe 20 Single pipe 21 Inner pipe 22 Outer pipe 23 Pipe body f Flow layer

Claims (10)

In a fluidized bed type reactor (A) in which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, a method of thermally decomposing an organic substance by contacting it with the mixed gas (g). hand,
Of the pyrolysis products of organic substances taken out from the reactor (A), at least a part of the pyrolysis product (x) which is liquid at room temperature is in a liquid state, and the side wall portion of the reactor (A). In order to blow into the fluidized bed (f) through the blow pipe (C) installed through the reactor and thermally decompose it in the reactor (A) .
A part of the mixed gas (g) introduced into the reactor (A) as a fluidized gas is blown into the fluidized bed (f) together with the liquid pyrolysis product (x) through the blowing pipe (C). A characteristic method for thermally decomposing organic substances. In the case of the blow pipe (C) having a single pipe structure or a double pipe structure composed of an inner pipe and an outer pipe and having a single pipe structure, the mixed gas (g) and the liquid The thermal decomposition product (x) is blown from a single pipe in a mixed state, and in the case of a blow pipe (C) having a double pipe structure, a mixed gas (g) is blown from one of the inner pipe and the outer pipe. The method for thermally decomposing an organic substance according to claim 1 , wherein a liquid thermal decomposition product (x) is blown from the other side. The reactor space velocity in the area above the installation height of the blow pipe (C) is u ₀ (m / sec), and the reactor space velocity in the area below is u ^* (m / m / sec). When sec) is set, the flow velocity u _L (m / sec) of the mixed gas (g) blown into the reactor (A) through the blow pipe (C) satisfies the following equations (1) and (2). The method for thermally decomposing an organic substance according to claim 1 or 2 , wherein the method is controlled in such a manner.
u _L ≧ u ₀ … (1)
u ^* ≧ u ₀ /2… (2) The method for thermally decomposing an organic substance according to claim 1 to 3 , wherein the organic substance is one or more selected from waste plastic, oil-containing sludge, waste oil, and biomass. The method for thermally decomposing an organic substance according to any one of claims 1 to 4 , wherein the mixed gas (g) further contains water vapor. The method for thermally decomposing an organic substance according to claim 5 , wherein the mixed gas (g) has a water vapor concentration of 20 to 70 vol%, a hydrogen concentration of 10 to 40 vol%, and a carbon dioxide concentration of 10 to 40 vol%. .. A method for producing a gaseous substance, which comprises recovering a pyrolysis product which is a gas at room temperature as a useful gaseous substance, which is produced by the thermal decomposition method according to any one of claims 1 to 6 . A fluidized bed reactor in which a mixed gas (g) containing at least hydrogen and carbon dioxide is introduced as a fluidized gas, and a reactor (A) that thermally decomposes an organic substance by contacting it with the mixed gas (g). )When,
The reactor (A) discharged from the gas containing pyrolysis products of the organic substance (g _p) and cooled to room temperature or ambient temperature near the thermal decomposition products of organic substances contained in the gas (g _p) a separation device by liquefying a portion separated from the gas (g _{p) (B),}
The reactor (A) is installed through the side wall portion of the separation device (B) in a fluidized bed at least a portion of the gas (g _p) thermal decomposition products of the liquid separated from the (x) (f) the a blow tube (C) blown into,
It has a supply means (F) for supplying a part of the mixed gas (g) introduced into the reactor (A) as a fluidized gas to the blow pipe (C).
The mixed gas (g) supplied to the blow pipe (C) by the supply means (F) is blown into the fluidized bed (f) together with the liquid pyrolysis product (x). Pyrolysis equipment for organic substances. The separation device (B) is a pyrolysis facility consisting of a sprinkler type device.
Further, a water removing device (D) for removing water from the liquid thermal decomposition product (x) separated by the separating device (B) and a liquid thermal decomposition in which the water is removed by the water removing device (D). The pyrolysis facility for an organic substance according to claim 8 , further comprising a supply means (E) for supplying at least a part of the product (x) to the blow pipe (C). In the case of the blow pipe (C) having a single pipe structure or a double pipe structure composed of an inner pipe and an outer pipe and having a single pipe structure, the mixed gas (g) and the liquid In the case of a blown pipe (C) having a double pipe structure in which the thermal decomposition product (x) is blown from a single pipe in a mixed state, the mixed gas (g) is emitted from one of the inner pipe and the outer pipe. The thermal decomposition equipment for organic substances according to claim 8 or 9 , wherein a liquid thermal decomposition product (x) is blown from the other side.

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