JP6227293B2 - Method for reducing the molecular weight of organic substances - Google Patents

Description

  The present invention relates to a method for modifying an organic substance to reduce its molecular weight in order to convert an organic substance such as plastic into a gaseous fuel, and a method for operating a blast furnace using a gas product obtained by the method. .

At present, most of waste plastic, oil-impregnated sludge, waste oil, etc. are incinerated. However, incineration treatment has a high environmental load such as CO ₂ generation, and there is a problem of thermal damage of the incinerator, and establishment of chemical recycling technology is required.
Among chemical recycling technologies, technologies for converting organic substances into gaseous fuels and liquid fuels have been variously studied mainly with respect to waste plastics. For example, the following proposals have been made.

In 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 material such as waste plastic, thereby hydrogenating the organic material with high efficiency. A method for increasing the heat of COG by decomposition and gasification is disclosed.
Further, Patent Document 2 discloses a method in which petroleum fluid contact catalyst (FCC) is used as a heat medium / catalyst and waste plastic is decomposed at a temperature of 350 to 500 ° C. to be converted into liquid fuel.
Further, in Patent Document 3, when pyrolyzing RDF, wood, etc., the gas generated by pyrolysis is steam reformed, and the gas having a high hydrogen concentration by this steam reforming is circulated to the pyrolysis section to generate hydrogen. A method of performing pyrolysis in a gas atmosphere with a high concentration is disclosed.

JP 2007-224206 A JP 2010-013657 A JP 2001-131560 A International Publication No. 2012/029293

However, the above prior art has the following problems.
First, regarding Patent Document 1, since the hydrogen concentration in COG is 60 vol% or more is limited to the end of the dry distillation in the coal dry distillation process, in the method of Patent Document 1, the gas flow path is opened at the end of the dry distillation. It is necessary to switch and supply COG of 600 ° C. or more containing a large amount of dust to a waste plastic hydrocracking reactor. However, it is difficult to stably operate the flow path switching valve for a long time under such a severe condition, and in this sense, it can be said that the technique is poor in feasibility. Furthermore, for efficient gasification of waste plastic, it is necessary to continuously supply COG containing 60 vol% or more of hydrogen to the hydrocracking reactor. In addition, it is necessary to install a hydrogen concentration meter and a flow path switching valve, which increases the equipment cost.

Moreover, although the method of patent document 2 advances catalytic cracking and aromatization by FCC catalyst addition, since it reacts by an inert gas flow, 13 mass% of heavy oil components and coke are produced | generated in total ( Example 1) is not a satisfactory level as a light fuel production technology.
Further, the gas generated by the method of Patent Document 3 is mainly H ₂ , CO, and CO ₂ , and the combustion heat is about 1800 kcal / Nm ³ that is slightly lower than that of the exhaust gas generated from the metallurgical furnace. The value is limited.

In order to solve such a problem, Patent Document 4 describes that an organic substance is efficiently reformed using a gas that can be stably supplied to reduce the molecular weight, and there is little heavy or carbonaceous matter. As a method of obtaining a high-calorie modified product containing a large amount, it was generated by a shift reaction by adding excess water vapor to an exhaust gas containing carbon monoxide generated in a metallurgical furnace to cause a shift reaction. A method is described in which a mixed gas containing hydrogen and carbon dioxide gas and water vapor that has not been consumed in the shift reaction is brought into contact with an organic substance, and the organic substance is reformed to reduce the molecular weight.
However, in the method of Patent Document 4, since a mixed gas is brought into contact with an organic substance in a reforming reactor such as a rotary kiln or a fixed bed reforming reactor, a solid organic substance such as plastic is brought into the reactor. There is a problem that easily causes troubles such as fusion.

  Therefore, an object of the present invention is to add hydrogen and carbon dioxide gas generated in the shift reaction to the exhaust gas containing carbon monoxide generated in the metallurgical furnace and cause the shift reaction to be consumed in the shift reaction. In the method of making a mixed gas containing water vapor that has not been made, contacting this mixed gas with an organic substance, and modifying the organic substance to lower the molecular weight, problems such as fusion of the organic substance in the reactor occur. It is another object of the present invention to provide a method capable of efficiently reducing the molecular weight of an organic substance.

  As a result of repeated investigations to solve the above problems, the present inventors have added an excess of water vapor to the exhaust gas containing carbon monoxide generated in the metallurgical furnace to cause the shift reaction, thereby generating the shift reaction. In a method in which a mixed gas containing hydrogen and carbon dioxide gas and water vapor that has not been consumed in the shift reaction is brought into contact with an organic substance and the organic substance is reformed to reduce the molecular weight, a specific metal is added. The organic material can be efficiently reduced in molecular weight without causing troubles such as fusion of the organic material by performing a molecular weight reduction reaction of the organic material in a fluidized bed using the contained granular material as a fluid medium. It has been found that there are particularly suitable conditions for the granular material used in the fluidized bed.

The present invention has been made on the basis of such findings and has the following gist.
[1] Addition of excess water vapor to the exhaust gas (g ₀ ) containing carbon monoxide generated in the metallurgical furnace to cause the shift reaction to consume the hydrogen and carbon dioxide generated by the shift reaction and the shift reaction In a method in which a mixed gas (g) containing water vapor that has not been formed is brought into contact with an organic substance and the organic substance is modified to reduce the molecular weight, the true density is 4 to 8 g / cm ^3. In a fluidized bed using a granular material (f) containing at least one selected from Fe, Ni, and Cr as a fluidized medium , the mixed gas (g) is brought into contact with the organic material, A method for reducing the molecular weight of an organic substance that is modified to reduce the molecular weight, wherein at least a part of the powder (f) is iron-containing dust generated in a steelmaking process. Molecularization method.

[2] A method for reducing the molecular weight of an organic substance according to the method of [1] , wherein the granular material (f) is iron-containing dust generated in a steelmaking process.
[3] In the method of [1] or [2 ] above, the organic substance to be modified is at least one selected from plastic, oil-containing sludge, waste oil, and biomass. Molecularization method.

[4] A method for reducing the molecular weight of an organic material according to the method of [3] , wherein at least a part of the organic material to be modified is a mixed molded product of plastic and wood.
[5] A method for reducing the molecular weight of an organic substance according to the method of [4 ] above, wherein the wood is at least one selected from construction waste wood, packaging / transport waste wood, and thinned wood.
[6] In any one of the methods [1] to [5] , the gas (g _p ) discharged from the fluidized bed is passed through a dust collector, and the fluid medium contained in the gas (g _p ) is collected. A method for reducing the molecular weight of an organic substance, comprising circulating the collected fluid medium in a fluidized bed.
[7] A method of operating a blast furnace, characterized in that a gas product generated by reducing the molecular weight of an organic substance by any one of the methods [1] to [6] is blown into a blast furnace.

According to the method for lowering the molecular weight of an organic substance according to the present invention, when the molecular weight of a high molecular weight organic substance such as plastic is reduced, the organic substance is melted in the reactor using a gas that can be stably supplied. Without causing troubles such as wearing, it is possible to obtain a gas reformed product that efficiently reforms organic substances to lower the molecular weight, has less heavy and carbon, and contains a large amount of light components, It can be implemented with relatively simple equipment. In addition, since CO ₂ produced by the shift reaction changes to CO during the reforming of the organic material, it is possible to carry out chemical recycling of the organic material without increasing the amount of CO ₂ generated. It becomes.
Moreover, according to the operating method of the blast furnace which concerns on this invention, the usage-amount of coke which is a reducing material can be reduced, and a carbon dioxide discharge reduction and the reduction of steelmaking cost can be aimed at.

In the shift reaction performed by adding water vapor to the converter gas, a graph showing the relationship between the amount of water vapor added and the composition of the gas after the shift reaction (calculated equilibrium composition at a temperature of 430 ° C.) Explanatory drawing which shows one Embodiment of the modification | reformation apparatus for reducing the molecular weight of an organic substance in this invention Ring die type compression molding granulator to obtain a mixed molded product of plastic and wood, and an explanatory diagram schematically showing the implementation status of compression molding granulation using this

In the method of the present invention, an excess water vapor is added to an exhaust gas (g ₀ ) containing carbon monoxide generated in a metallurgical furnace (hereinafter sometimes referred to as “metallurgical furnace generated exhaust gas”) to cause a shift reaction. A mixed gas (g) containing hydrogen and carbon dioxide gas generated in the shift reaction and water vapor not consumed in the shift reaction, and this mixed gas (g) (hereinafter sometimes referred to as “shift reaction product gas”). In the method of contacting the organic material with the organic material and modifying the organic material to reduce the molecular weight, the true density is 4 to 8 g / cm ³ and contains at least one selected from Fe, Ni, and Cr. In a fluidized bed (fluidized bed reactor) in which the granular material (f) is at least a part of the fluidized medium, the mixed gas (g) is brought into contact with an organic substance, and the organic substance is modified to reduce the molecular weight. Note that adding excess steam to the exhaust gas (g ₀ ) means adding steam so that excess steam that is not consumed in the shift reaction remains in the mixed gas (g).

In such a method of the present invention, the reduction of the molecular weight of the organic substance is efficiently promoted even at a relatively low reaction temperature, the hydrogen consumption is small, and the generation of heavy components and carbonaceous matter is hardly observed.
In general, it is known that a high molecular weight organic substance such as plastic begins to thermally decompose when heated at a temperature of 300 to 400 ° C. or higher, but at this time, it becomes lighter and heavier. Coexistence of hydrogen during thermal decomposition is effective in suppressing heavy formation and reducing the molecular weight because hydrogen addition reaction and hydrocracking reaction to hydrocarbon species proceed. However, the high temperature is required for hydrocracking, and the hydrogen consumption is a problem.

On the other hand, steam reforming and carbon dioxide reforming can be regarded as oxidation of hydrocarbons by oxygen in H ₂ O and CO ₂ molecules, achieving low molecular weight and suppressing carbonaceous production with a small amount of hydrogen addition. it can. Furthermore, steam reforming and carbon dioxide reforming are characterized in that the reaction temperature decreases as the carbon chain of the organic molecule to be modified becomes longer. In the method of the present invention, the low molecular weight of an organic substance is efficiently promoted even at a relatively low reaction temperature, the amount of hydrogen consumption is small, and the generation of heavy components and carbonaceous matter is hardly recognized. It is considered that the four reactions of hydrogenation, hydrocracking, steam reforming, and carbon dioxide reforming proceed simultaneously by reforming (reducing molecular weight) the organic substance using (g).

For example, the exhaust gas generated from a metallurgical furnace such as a converter usually contains about 25 to 80 vol% of CO. Therefore, when water vapor is added thereto, H ₂ and CO ₂ are generated by the following shift reaction (1).
CO + H ₂ O → H ₂ + CO ₂ (1)
In the method of the present invention, since excess water vapor is added to the exhaust gas (g ₀ ), the mixed gas (g) after the shift reaction includes H ₂ , CO ₂ generated by the shift reaction, and H ₂ O of excess addition. Will be included. In the reforming of organic substances (lower molecular weight) by this shift reaction product gas (g), four reactions of hydrogenation, hydrocracking, steam reforming, and carbon dioxide reforming by each gas component proceed simultaneously. it is conceivable that.

In the present invention, the concentration of water vapor, hydrogen, and carbon dioxide in the gas is controlled by appropriately controlling the excess ratio of water vapor added excessively to the exhaust gas (g ₀ ) and the reaction rate of the shift reaction. A mixed gas (g) for material modification can be obtained. However, the general composition of the metallurgical furnace generated exhaust gas stored in the gas holder (for example, a general gas holder used in a steelworks) is CO: 50 to 70 vol%, CO2: 10 to ₂₀ vol%, N _{2: 10~20vol%,} H _2: because of the order 0~5vol% (including other saturated steam) generally is not necessary to carry out until the reaction rate control of the shift reaction, only by adjusting the excess percentage of water vapor Thus, each concentration of water vapor, hydrogen and carbon dioxide in the mixed gas (g) can be controlled to a desired level.
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, a method in which the shift reactor length is reduced or the catalyst charge amount is reduced is generally used. In this case, the shift reactor length and the catalyst charge amount are almost until equilibrium. What is necessary is just to set it as about 1 / 2-1 / 4 in the case of advancing reaction.

As an example, converter gas of 100 kmol / h (= 2240 Nm ³ / h) having a composition of CO: 65 vol%, CO ₂ : 15 vol%, N ₂ : 18 vol%, H ₂ : 1 vol%, H ₂ O: 1 vol% In the case of performing the shift reaction by changing the amount of water vapor added from 60 kmol / h (= 1340 Nm ³ / h) to 540 kmol / h (= 1100 Nm ³ / h), the amount of water vapor added and the composition of the gas after the shift reaction ( The calculated equilibrium composition at a temperature of 430 ° C. is shown in FIG. According to this, it can be seen that the concentration of water vapor, hydrogen, and carbon dioxide in the mixed gas (g) can be controlled only by adjusting the amount of water vapor added, and a preferable gas composition as described later can be obtained. In addition, it is well known that the shift reaction usually proceeds to almost equilibrium.

Furthermore, in the present invention, by reducing the molecular weight of the organic substance using a fluidized bed having a large heat transfer rate, it is possible to prevent the rate of supply of reaction heat necessary for the reduction of the molecular weight from being reduced. It is possible to prevent troubles such as the high molecular weight organic substance being fused and clogged. In addition, by using a granular material (f) having a true density of 4 to 8 g / cm ³ and containing at least one selected from Fe, Ni, and Cr as the fluidized medium of the fluidized bed, Since the powder (f) also functions as a fluid catalyst, the organic substance can be efficiently modified to obtain a low molecular weight product.

In addition, part of the granular material (f), which is a fluidized medium, and ash of organic substances such as plastic are scattered in the gas discharged from the fluidized bed reactor. It is collected by an installed dust collector, and among these, the granular material (f) is usually circulated (returned) to the fluidized bed reactor. By using a granular material having a true density larger than that of a general fluidized bed fluid medium and having a true density of 4 g / cm ³ or more as the granular material (f) that is a fluidized medium of the fluidized bed and functions as a catalyst. In the above dust collector, the particulate matter (f) is collected separately from the ash content of the organic substance (that is, the particulate matter (f) and the ash content of the organic substance are collected separately) It becomes easy to selectively circulate (return) (f), and it is possible to prevent the granular material (f) from being diluted with ash that is inert to the low molecular weight reaction. However, the powder (f) having a true density exceeding 8 g / cm ³ has low fluidity.

Hereinafter, details and preferred conditions of the method of the present invention will be described.
In the present invention, the reason why the metallurgical furnace generated exhaust gas is used as the exhaust gas (g ₀ ) for the shift reaction is that the metallurgical furnace generated exhaust gas contains carbon monoxide at a relatively high concentration and the concentration of unnecessary nitrogen is low. . As the metallurgical furnace-generated exhaust gas (g ₀ ) containing carbon monoxide, any one can be used. The most representative is the converter gas generated from the converter where the decarburization process of the steel manufacturing process is performed, but other than that, for example, it is generated from a hot metal pretreatment furnace, a smelting reduction furnace, a shaft furnace, etc. Exhaust gas to be used can be exemplified, and one kind or a mixture of two or more kinds thereof can be used.

The secondary combustion rate (CO ₂ / (CO + CO ₂ ) × 100), which is the rate at which carbon monoxide produced in the metallurgical process is further oxidized to produce carbon dioxide, is generally only about 10 to 50%. Also, in the exhaust gas (g ₀₎ are also included hydrogen and nitrogen, H ₂ concentration varies depending on the metallurgical process, it is about 0~20vol%. Nitrogen is supplied for in-furnace agitation and flue safety, and the concentration in the exhaust gas (g ₀ ) is about 10 to 30 vol%.

From the above points, the composition of general metallurgical furnace-generated exhaust gas (g ₀ ) is generally in the following range.
CO: 80-25 vol% (equivalent to 10-50% secondary combustion rate)
CO _2: 10~25vol% (corresponding to the secondary combustion rate 10-50%)
N _2: 10~30vol%
H2: 0 to ₂₀ vol%

Although carbon monoxide is required for the shift reaction, there is no particular problem with the composition of the exhaust gas (g ₀ ) as long as the gas composition is in the above range. Here, nitrogen does not contribute at all to the chemical reaction (shift reaction, hydrogenation, hydrocracking, steam reforming, carbon dioxide reforming) occurring in the present invention, while diluting the gaseous fuel produced, Low combustion heat (hereinafter referred to as “LHV”) is reduced. In particular, when the nitrogen concentration exceeds 50 vol%, the LHV of the gaseous fuel is significantly reduced and the shift reaction rate tends to be reduced. Therefore, the nitrogen concentration is preferably within the above composition range.

As mentioned earlier, gas holder (e.g., typical gas holder used in steelworks) General composition of metallurgical furnace generation exhaust gas to be stored in the, CO: 50~70vol%, CO 2 : 10 ˜20 vol%, N ₂ : 10 to ₂₀ vol%, H ₂ : 0 to 5 vol% (including saturated steam in addition), and this composition is high in the composition of the above general metallurgical furnace generated exhaust gas. It corresponds to the CO concentration composition. Since the gas stored in the gas holder is used as fuel gas at each factory in the steelworks, it is necessary to prevent a decrease in combustion efficiency at the use destination. Therefore, setting the lower limit value of the CO concentration in the gas as a storage condition in the gas holder is the reason why the composition has a high CO concentration.
In the present invention, the composition of the exhaust gas generated in the general metallurgical furnace as described above is used even if the exhaust gas has a relatively high CO concentration as stored in a general gas holder used in a steelworks. However, it can be used as exhaust gas (g ₀ ).

Incidentally, some metallurgical furnace-generated exhaust gas (g ₀ ) has a relatively low carbon monoxide concentration and a high nitrogen concentration, such as blast furnace gas. Such metallurgical furnace-generated exhaust gas (g ₀ ) Alternatively, at least a part of the nitrogen contained may be separated (removed) to increase the carbon monoxide concentration, and then an excessive water vapor may be added to cause the shift reaction. Although it cannot be uniformly determined because of the required specification of the combustion heat of the gaseous fuel generated by lowering the molecular weight of the organic substance, if the nitrogen concentration in the exhaust gas exceeds 30 vol%, a nitrogen separation step is provided and the exhaust gas ( It is preferable to separate (remove) at least part of the nitrogen from g ₀ ).
As typical exhaust gas that is preferably subjected to nitrogen separation, blast furnace gas can be mentioned, but in addition to this, exhaust gas generated from an electric furnace or a shaft furnace operating under a condition where the nitrogen concentration becomes high can be mentioned. it can. In addition, the nitrogen gas is separated from an exhaust gas containing a relatively high concentration of carbon monoxide such as a converter gas, and the shift reaction can be performed after further increasing the carbon monoxide concentration.

There is no particular restriction on the method for separating nitrogen from exhaust gas, and any method such as adsorption separation method or distillation separation method can be applied. However, since the boiling point difference between nitrogen and carbon monoxide is small, the adsorption separation method is Particularly preferred. For example, since activated carbon supporting Cu ⁺ , which is known as a CO adsorbent, also adsorbs CO ₂ , blast furnace gas (general composition: N ₂ : 50 vol%, CO ₂ ) is obtained by PSA method using Cu ⁺ supported activated carbon as an adsorbent. : _25vol%, CO 2: approximate composition as desorbed gas from 25 vol%) is _{N 2: 15vol%, CO:} 45vol%, CO 2: it is possible to obtain a 40 vol% of the gas, which separates the nitrogen in the blast furnace gas Thus, the carbon monoxide is concentrated.

The shift reaction in the method of the present invention may be carried out by a known method and is not particularly limited. Generally, water vapor is added to the metallurgical furnace-generated exhaust gas (g ₀ ) in advance, and this is introduced into a fixed bed reactor filled with a catalyst to perform a shift reaction. Alternatively, the water vapor to be added in advance may be partially used, the catalyst may be packed in multiple stages in the reactor, and the remaining water vapor may be added between the catalyst layer and the catalyst layer.
If water vapor, hydrogen, and carbon dioxide are added to the metallurgical furnace-generated exhaust gas (g ₀ ) without performing the shift reaction as in the present invention, the mixture for organic substance modification obtained by the shift reaction in the present invention is used. Although a gas having a composition equivalent to that of the gas (g) can be obtained, in such a method, in addition to water vapor, expensive hydrogen gas and carbon dioxide gas must be added, resulting in an increase in cost.

In the present invention, the mixed gas (g) for reforming the organic substance obtained by the shift reaction contains water vapor, hydrogen and carbon dioxide gas, and there is no particular limitation on the concentration thereof. Therefore, the water vapor concentration is preferably 5 to 70 vol%. In other words, when the water vapor concentration is low, the decomposition rate of organic substances such as plastics is low. However, by setting the water vapor concentration to 5 vol% or more, a certain level of organic material decomposition rate can be secured, and the production rate of gaseous fuel (gas Conversion rate) can be maintained at a constant level, and the amount of heavy components produced can be reduced. On the other hand, when the water vapor concentration is high, CO ₂ tends to remain in the reformed product gas of organic substances (gas generated by the reforming of organic substances, hereinafter the same), and the LHV of the gaseous fuel decreases. However, if the water vapor concentration is 70 vol% or less, it is possible to suppress the residual CO _{2 in} the reforming reaction product gas, and it is also possible to suppress the decrease in the LHV of the gaseous fuel / liquid fuel.
Further, from the viewpoint of ensuring the decomposition rate of the organic substance, both the hydrogen concentration and the carbon dioxide concentration of the mixed gas (g) are preferably 5 vol% or more.

Moreover, for the following reasons, the more preferable composition of the mixed gas (g) for organic substance reforming is: water vapor concentration: 20 to 70 vol%, hydrogen concentration: 10 to 40 vol%, carbon dioxide concentration: 10 to 40 vol%. It is. In addition, it does not prevent that other gas components (for example, nitrogen etc.) are contained in this mixed gas (g). By setting the water vapor concentration to 20 vol% or more, the decomposition rate of the organic substance can be sufficiently increased, and the LHV of the gaseous fuel can be increased. The reason for setting the water vapor concentration to 70 vol% or less is as described above. By setting the hydrogen concentration to 10 vol% or more (more preferably 12 vol% or more), it is possible to suppress the CO ₂ from remaining in the gaseous fuel even when the organic substance is reformed at a relatively low temperature. Can do. By setting the carbon dioxide gas concentration to 10 vol% or more (more preferably 13 vol% or more), H ₂ which is a low-calorie gas component is less likely to remain in the gaseous fuel as compared to hydrocarbons and CO. Moreover, the decomposition rate of organic substances, such as a plastic, can be made into a preferable level by making hydrogen concentration and carbon dioxide gas concentration into 40 vol% or less. Moreover, from the above viewpoints, a more preferable gas composition of the mixed gas (g) is a water vapor concentration: 25 to 65 vol%, a hydrogen concentration: 15 to 35 vol%, and a carbon dioxide concentration: 15 to 35 vol%. In addition, it does not prevent that other gas components (for example, nitrogen etc.) are contained in this mixed gas (g).

Next, conditions for modifying (lowering the molecular weight) of an organic substance with the mixed gas (g) obtained by the shift reaction will be described.
In the present invention, there is no particular limitation on the organic material to be reduced in molecular weight by modification, but a high molecular weight organic material is suitable, for example, plastic (usually waste plastic), oil-containing sludge, waste oil, biomass. One or more of these can be targeted.

Although there is no special restriction | limiting in the kind of target plastic, For example, an industrial waste type | system | group, a target plastic of the container packaging recycling law etc. can be mentioned. More specifically, polyolefins such as PE and PP, thermoplastic polyesters such as PA and PET, elastomers such as PS, thermosetting resins, synthetic rubbers, foamed polystyrene and the like can be mentioned. In addition, inorganic substances such as fillers are added to many plastics. However, in the present invention, such inorganic substances are not involved in the reaction. It is discharged from the reactor for reducing the molecular weight. In addition, the plastic is pre-cut into an appropriate size as required, and then charged into the reforming reactor.
Further, if the plastic contains a chlorine-containing resin such as polyvinyl chloride, chlorine is generated in the reforming reactor, and this chlorine may be contained in the product. Therefore, when the plastic may contain a chlorine-containing resin, it is preferable to introduce a chlorine absorbent such as CaO into the reforming reactor so that the chlorine content is not contained in the gas product. .

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

Examples of the waste oil include, but are not limited to, various used mineral oils, natural and / or synthetic fats and oils, and various fatty acid esters. Moreover, the mixture of these 2 or more types of waste oil may be sufficient. In addition, in the case of waste oil generated in the steel mill rolling process, it generally contains a large amount of water (usually more than about 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.
When the organic substance contains water, water vapor is generated in the reforming reactor. Therefore, the excess ratio of water vapor added in the shift reaction is determined in consideration of the amount.

  Examples of biomass include sewage sludge, paper, wood (for example, construction waste wood, packing / transport waste wood, thinned wood, etc.), and processed biomass such as solid waste fuel (RDF). However, it is not limited to these. Since biomass usually contains a large amount of water, it is preferable to dry it beforehand in view of energy efficiency. In addition, in the case of biomass containing relatively high concentrations of alkali metals such as sodium and potassium, alkali metals may be deposited in the reforming reactor. It is preferable to keep. Large biomass such as construction waste wood and packaging / transport waste wood is cut in advance and put into the reforming reactor.

  Moreover, as an organic substance used as object, the mixed molded product of plastic (usually waste plastic) and wood (molded product of the mixture of plastic and wood) is preferable. This mixed molding is a compression molding of a mixture of plastic and wood (both small-sized materials such as small blocks, granules or small pieces), and frictional heat generated during the molding process and / or external heating applied during the molding process. Thus, the plastic is at least partially melted or softened, and the melted or softened plastic is solidified as a binder. In this case, only the plastic on the surface of the mixed molded product may be melted or softened, and the melted or softened plastic may be used as a binder to form a solidified outer shell. The wood is preferably one or more of construction waste wood, packaging / transport waste wood, and thinned wood from the viewpoint of effective use of resources, but is not limited thereto. Packing / transporting waste wood refers to wood that is no longer needed after being used for packing or transporting work, such as waste wooden boxes and waste pallets.

The reason why the above-mentioned mixed molded article is preferable as the organic substance to be used in the present invention is that (a) the chlorine contained in the plastic is not a chlorine-containing wood (construction waste wood, packaging / transport waste wood) , Thinned wood, etc.), (b) the ash contained in the plastic is diluted with low ash wood, (c) at least partly due to frictional heat in the molding process as described above Plastics that have been melted or softened as a binder, improve the formability of wood and improve its handling, and (d) low molecular weight organic substances due to oxygen atoms usually contained in wood at relatively high concentrations And the like are promoted.
Therefore, it is preferable that at least a part of the organic material to be modified is a mixed molded product of plastic and wood (for example, one or more of construction waste wood, packaging / transport waste wood, and thinned wood).

  The ratio of wood in the mixed molded product is preferably about 10 to 70% by mass, and more preferably about 20 to 60% by mass. When the ratio of the wood is less than 10% by mass, the effects (a), (b), and (d) described above are hardly exhibited. On the other hand, if the proportion of wood exceeds 70% by mass, the binder effect due to the molten or softened plastic of (c) above is reduced. Moreover, when the ratio of wood exceeds 70 mass%, the combustion heat of the gas product produced | generated by a low molecular-ized reaction will fall.

  There is no restriction | limiting in particular in the manufacturing method of the mixed molding of a plastic and wood. Usually, plastic and wood (for example, one or more of construction waste wood, packaging / transport waste wood, and thinned wood) are preliminarily crushed so that they have a small diameter, granular, or small piece of material. It becomes. When crushing, plastic and wood may be separately crushed, or plastic and wood may be simultaneously fed into one crusher for crushing. The size of the plastic or wood after the crushing process, that is, the screen of the crusher is determined according to the size of the target mixed molded product, for example, the outer diameter using a compression molding granulation method with a ring die described later. Is about 6 to 30 mm, the screen opening of the crusher is suitably about 10 to 30 mm. In addition, in order to protect the crusher and the forming granulator, it is common to remove metal foreign matters in advance by wind separation or magnetic separation.

  Plastic and wood are mixed in advance or in the molding process and compression molded to a predetermined size. There is no special restriction | limiting in this shaping | molding method, For example, well-known methods, such as the compression molding granulation method by a ring die, can be applied. The plastic is at least partially melted or softened by frictional heat generated in the molding process of the mixture of plastic and wood or external heating applied in the molding process, and the molded product is solidified by using the molten or softened plastic as a binder.

  FIG. 3 schematically shows a ring die type compression molding granulator and the implementation of compression molding granulation using the same. This compression molding granulator has a die ring 6 in which a large number of die holes 60 (round holes) are provided in the entire circumference, and is rotatable inside the die ring 6 so as to be in contact with the inner peripheral surface of the die ring. A plurality of (usually 2 to 3) rolling rollers 7 arranged on the die and a cutting blade 8 for cutting the mixed molded product extruded from the die hole 60 and scraping off the outer peripheral surface of the die ring. ing. The die ring 6 and the rolling roller 7 are both rotatably supported by an apparatus main body (not shown). The die ring 6 is driven to rotate by a driving device, whereas the rolling roller 7 is a non-driven free drive. This roller body rotates with the rotation of the die ring 6 by friction with the inner peripheral surface of the die ring. Moreover, although the hole diameter of the die hole 60 is determined according to the magnitude | size (diameter) of the mixture which should be granulated, it is about 3-20 mm normally.

  In this ring die type compression molding granulator, the die ring 6 is rotationally driven in the direction of the arrow in the figure, and accordingly, the rolling roller 7 is also rotated in the direction of the arrow. In this state, plastic and wood that have been crushed to an appropriate size according to the size of the die hole diameter are put into the die ring 6 from a not-shown slot, and the thrown material is a rolling roller. 7 is pressed into the die hole 60 of the die ring 6 while being compressed and compressed between the inner peripheral surface of the die ring (there is also a crushing action by crushing). The material (mixture) pushed into the die hole 60 is compressed in the process of passing through the die hole 60, and the surface (surface in contact with the inner peripheral surface of the die hole) by frictional heat with the inner peripheral surface of the die hole. The plastic is melted or softened. The material (mixture) that has passed through the die hole 60 is sequentially pushed out in the form of a column to the outer peripheral surface side of the die ring 6, and at this time, the plastic on the surface that has been melted or softened is solidified. An outer shell is formed using the solidified plastic as a binder. Then, when the cylindrical shaped product pushed out to the outer peripheral surface of the die ring reaches the position of the cutting blade 8 by the rotation of the die ring 6, it is scraped off from the outer peripheral surface of the die ring 6 by the cutting blade 8, thereby A mixed molded product is obtained.

The reaction temperature during organic substance modification is preferably as follows according to the type of organic substance.
In the case of plastic or biomass, the reaction temperature is suitably about 400 to 900 ° C. When the reaction temperature is less than 400 ° C., the decomposition rate of plastic and biomass is low. On the other hand, when the reaction temperature exceeds 900 ° C., the production of carbonaceous matter increases.
In addition, when a mixture molded product of plastic and wood (for example, one or more of construction waste wood, packaging / transport waste wood, and thinned wood) is used, the reaction temperature is 400 to 900 ° C. for the above reasons. The degree is appropriate.

  In addition, since the wood with soft tree structure such as paulownia has a relatively high reactivity, the reaction temperature is set to 20 to 20 in comparison with the case of plastic alone when targeting a mixed molded product of such wood and plastic. It can be lowered by 30 ° C. However, the density and specific gravity of the timber vary greatly depending on the position of a single tree as well as the type and location of the tree. Furthermore, since waste wood becomes a mixture of various woods, it is not always possible to lower the reaction temperature. From such a viewpoint, it is appropriate that the reaction temperature of the mixed molded product of plastic and wood is about 400 to 900 ° C.

In the case of oil-containing sludge or waste oil, the reaction temperature is suitably about 300 to 800 ° C. When the reaction temperature is less than 300 ° C., the decomposition rate of oil-containing sludge and waste oil becomes low. On the other hand, even if the reaction temperature exceeds 800 ° C., there is no effect on the reforming (lower molecular weight) characteristics of the oil-containing sludge or waste oil, but it is not economical because the temperature is higher than necessary.
In the case where a mixture of plastic and / or biomass (including “mixed molding of plastic and wood”) and oil-containing sludge and / or waste oil is targeted, the reaction temperature is 400 to A temperature of about 800 ° C. is appropriate. Since almost no influence of pressure is observed, it is economical to operate the reforming reactor at normal pressure or slightly pressurized of about several kg / cm ² .

In the present invention, a fluidized bed reactor is used as the reforming reactor. That is, the mixed gas (g) is brought into contact with the organic substance in the fluidized bed, and the organic substance is modified to reduce the molecular weight. As already described, in the present invention, the four reactions of hydrogenation, hydrocracking, steam reforming, and carbon dioxide reforming proceed simultaneously, so that organic substances such as plastics can be made low molecular weight with high efficiency. In fact, it is clear that in addition to these, a pyrolysis reaction also proceeds. Of these, hydrocracking, steam reforming, carbon dioxide reforming, and thermal cracking are endothermic reactions, and the exothermic reaction is only hydrogenation. Therefore, this reaction is generally endothermic, and it is necessary to supply reaction heat from the outside.
This is not a big problem when reducing the molecular weight of plastics batchwise, but the problem when conducting reactions in a flow-type fixed bed reactor is that the rate of supply of reaction heat becomes rate limiting, and plastics are not contained in the reactor. For example, the heat efficiency is deteriorated by fusing or supplying heat higher than necessary to prevent fusing, and the plastic is carbonized by the high-temperature supply heat. It is done.

On the other hand, the fluidized bed reactor is characterized by the fact that the temperature in the fluidized bed is almost uniform and the heat exchange is very fast, so that the problems that occur in the fixed bed reactor described above can be avoided. it can. In the present invention, at least a part of the fluidized medium in the fluidized bed (preferably the main body of the fluidized medium) has a true density of 4 to 8 g / cm ³ and at least one selected from Fe, Ni, and Cr. A powder (f) containing seeds is used. Fe, Ni, and Cr are all active in this reaction, and the low molecular weight reaction proceeds with high efficiency by the powder (f) functioning also as a catalyst. On the other hand, in the waste plastic gasification technology by the conventional fluidized bed, sand is often used as a fluidized medium. However, sand not only has no catalytic activity, but also has a slightly larger particle size as a fluid medium, and the conditions under which a stable fluidized bed can be formed are limited, making it difficult to deal with various raw materials. In addition, the presence form of Fe, Ni, Cr contained in a granular material (f) does not ask | require a distinction, such as a metal and an oxide. The reason why the true density of the powder (f) is 4 to 8 g / cm ³ will be described later.

  The total content of Fe, Ni and Cr in the powder (f) is preferably about 20 to 90% by mass, and more preferably about 30 to 80% by mass. When the content is less than 20% by weight, the true density of the granular material (f) becomes small, so that the granular material (f) scattered in the gas discharged from the fluidized bed reactor is separated from the ash content of the organic substance. The collection (collection in a state where both are separated) tends to be insufficient. On the other hand, if the content exceeds 90% by mass, the true density becomes excessive and the fluidity is lowered.

FIG. 2 shows an embodiment of a reforming apparatus for reducing the molecular weight of an organic substance in the present invention, wherein 1 is a fluidized bed reactor, 2 is a discharge pipe for discharging gas from the fluidized bed reactor 1, 3a is a primary dust collector (upstream first stage dust collector) provided in the discharge pipe 2, and 3b is also a secondary dust collector (downstream second stage dust collector). Generally, the primary dust collector 3a is a cyclone, but the type of the secondary dust collector 3b is arbitrary, and may be a dry dust collector or a wet dust collector. When the secondary dust collector 3b is a dry dust collector, the exhaust gas is not cooled to the condensation temperature of the liquid product, so that the product passing through the secondary dust collector 3b remains in a gaseous state. A cooler, an oil / water separator, etc. are installed on the downstream side, and separated into gas products, liquid products, and waste water. On the other hand, when the secondary dust collector 3b is a wet dust collector, the exhaust gas is cooled and the liquid product is condensed, so that the product passing through the secondary dust collector 3b is a gas product and is captured by the secondary dust collector 3b. The collected material will be a mixture of ash, wastewater, and liquid product. Therefore, an oil / water separator is installed in the mixture discharge system to separate the liquid product.
In FIG. 2, the primary dust collector 3 a is installed outside the fluidized bed reactor 1, but may be installed inside the fluidized bed reactor 1.

In the fluidized bed reactor 1, the mixed gas (g) is introduced into the wind box portion 11 on the lower side of the dispersion plate 10, and the mixed gas (g) is blown out of the dispersion plate 10, thereby flowing above the dispersion plate 10. A fluidized bed 4 is formed by the medium. An organic substance such as plastic is supplied to the fluidized bed 4 from the upper part of the fluidized bed reactor 1 and is reduced in molecular weight by reacting with the mixed gas (g) in the fluidized bed 4 to become a gas product. After the gas (g _p ) containing this gaseous product is discharged through the discharge pipe 2, the ash content of the fluid medium and organic substances scattered in the gas (g _p ) is captured by the primary dust collector 3a and the secondary dust collector 3b. However, the fluid medium and the organic ash are collected as separated as possible. In other words, the primary dust collector 3a mainly collects the fluid medium and prevents the ash from being collected as much as possible, and the secondary dust collector 3b mainly collects the ash of the organic substance. For this purpose, as will be described later, it is important to optimize the true density of the granular material (f) that is a fluid medium. The collected matter mainly composed of the fluidized medium collected by the primary dust collector 3 a is circulated to the fluidized bed reactor 1 through the return pipe 5. Note that the primary dust collector 3a and the return pipe 5 may be disposed in the free board portion in the upper part of the fluidized bed reactor 1. The gas (g _p ) that has passed through the secondary dust collector 3b is recovered, but the gas product contained in this gas (g _p ) is partly used as gaseous fuel and the other part is condensed. Each can be used as a liquid fuel.
As described above, in the present invention, the gas (g _p ) discharged from the fluidized bed is passed through the dust collector, the fluid medium contained in the gas (g _p ) is collected, and the collected fluid medium is fluidized. It is preferred to circulate through the layers.

The powder particles (f) constituting the fluid medium have a true density of 4 to 8 g / cm ³ , more preferably 4 to 7.5 g / cm ³ . As described above, the granular material (f) which is a fluidized medium and the ash content of organic substances are scattered in the gas (g _p ) discharged from the fluidized bed reactor 1, so these are gas (g _p ) by a dust collector. Of these, the granular material (f) is circulated in the fluidized bed reactor 1. When the true density of the granular material (f) is less than 4 g / cm ³ , since the density difference from the ash content of the organic substance is small, it becomes difficult to separate and collect from the organic ash content. Separation of ash tends to be insufficient. Specifically, in FIG. 2, it becomes difficult to collect mainly the granular material (f) in the primary dust collector 3 a, and a considerable amount of organic ash is also collected. As a result, the granular material (f) separated from the gas (g _p ) and circulated to the fluidized bed reactor 1 is diluted with ash that is inert to the low molecular weight reaction, and the catalyst of the fluidized bed 4 The activity will decrease continuously. On the other hand, when the true density of the granular material (f) exceeds 8 g / cm ³ , the fluidity as a fluid medium decreases. Here, a true density means the density measured using a pycnometer based on JIS-K-0061.

Even when the fluid medium collected and separated by the primary dust collector 3a is not circulated to the fluidized bed reactor 1, if the true density of the powder (f) is less than 4 g / cm ³ , the powder (f) It is difficult to collect the ash separately, and the powder (f) is still diluted by the ash. When steelmaking dust as described later is used as the granular material (f), this steelmaking dust is very inexpensive, so it is not necessary to circulate the steelmaking dust collected by the dust collector to the fluidized bed reactor for reuse. However, since the steelmaking dust is usually returned to the ironmaking process to recover the iron content, if a considerable amount of ash is contained therein, the amount of slag generated in the ironmaking process is increased by this ash. Therefore, in any case, in order to prevent the granular material (f) collected from the gas (g _p ) from being diluted with ash, the true density of the granular material (f) must be 4 g / cm ³ or more. I must.

As the granular material (f) which is a fluid medium and functions as a catalyst, a known Ni-based reforming catalyst or Ni-based hydrogenation catalyst can be used, but (i) it has a high catalytic activity because it contains a large amount of iron. Steelmaking for reasons such as being high, (ii) having a true density in the range of 4-8 g / cm ³ and being fine particles and therefore suitable as a fluid medium, (iii) being available in large quantities and being inexpensive. It is particularly preferable to use iron-containing dust generated in the process (hereinafter referred to as “steel-making dust” for convenience of explanation). Steelmaking dust generally contains 30% by mass or more of iron. Since this steelmaking dust is generally collected by a wet process, a drying process is necessary, but a classification process or the like is not necessary.

Steelmaking dust is iron-containing dust generated mainly in a steelmaking process performed using a converter, and examples of the steelmaking process include a dephosphorization process, a decarburization process, and a stainless steel refining process. It is not limited to these. In the present invention, one or more of these steelmaking dusts can be used.
Although the rate of steelmaking dust varies from steelworks to steelworks, the amount generated is proportional to the amount of crude steel produced, so it is available in large quantities. Moreover, since the value of steelmaking dust is equivalent to that of crude steel, it is very inexpensive at around tens of thousands of yen per ton. On the other hand, a commercially available catalyst costs several million yen per ton, and it is very advantageous in terms of cost to use steelmaking dust as the granular material (f).

Steelmaking dust generally has a particle size distribution with a particle size lower limit of about 0.1 μm and an upper limit of about 200 μm, a median diameter (d50) of about 5 to 30 μm, and a specific surface area of 10 to 20 m ² / g. A coarse particle having a particle size distribution in which the lower limit of particle size is about 1 μm, the upper limit is about 2000 μm, the median diameter (d50) is about 30 to 200 μm, and the specific surface area is 1 m ² / g or less. There is grain dust. In general, exhaust gas discharged mainly from converters in the steelmaking process is collected in a wet form, but the amount that can be separated from water without adding a flocculant is coarse dust, and the addition of a flocculant is necessary for separation. Minutes are fine dust.

  In the present invention, either fine dust or coarse dust may be used. However, when fine dust and coarse dust are compared, fine dust has a higher specific surface area than coarse dust and therefore has higher catalytic activity, while the stability in fluidized state is better than coarse dust than fine dust. Is excellent. Further, since the iron content on the surface of the steelmaking dust particles is oxidized, the proportion of the oxidized iron content is increased in the fine dust having a larger specific surface area. For this reason, since the true density is larger in the coarse dust than in the fine dust, the blowing power of the mixed gas (g) which is a fluidized gas is larger in the case where the coarse dust is used. From the above points, by mixing and using fine dust and coarse dust, it is possible to form a fluidized bed in which high catalytic activity, stability in a fluidized state, and suppression of blowing power are ensured in a well-balanced manner. .

  A suitable mixing ratio of the fine dust and the coarse dust is not limited because it depends on the ratio [Lf / D] of the fluidized bed height Lf and the inner diameter D of the reactor, but generally, the fine dust and the coarse dust are mixed. The ratio [fine dust: coarse dust] (mass ratio) is suitably about 1:10 to 1: 5 when Lf / D is about 0.1 to 0.5, and Lf / D is 0.00. When the ratio is more than 5 to 2, about 1: 5 to 1: 1 is appropriate, and when Lf / D is more than 2 to about 10, about 1: 1 to 5: 1 is appropriate.

Moreover, as a granular material (f), what carried out the classification process to about several dozen-several hundred micrometers after drying a mill scale etc. besides the steelmaking dust mentioned above can also be used. Such a classified product such as mill scale contains a large amount of iron as well as steelmaking dust, so it can be used alone as a granular material (f), but both catalytic activity and flow characteristics are better than steelmaking dust. Since it is low, it is preferable to use it mixed with steelmaking dust.
In addition, reduced iron powder produced by reducing the mill scale and atomized iron powder produced from molten steel by the water atomization method can be used alone as a powder (f). Since it is large, it is better to mix it with steelmaking dust and use it with good fluidity.
Therefore, the powder (f) is at least partly made of steelmaking dust, preferably mainly made of steelmaking dust (that is, containing 50% by mass or more of steelmaking dust), more preferably steelmaking dust. It is desirable to consist of.

  The fluid medium is mainly composed of the powder (f) (that is, containing 50% by mass or more of the powder (f)), but other powders may be added. For example, by mixing one or more inorganic powders such as alumina powder and silica sand, the fluidity can be further improved and the increase in the blowing power of the mixed gas (g) can be suppressed. When the inorganic powder is mixed, the mixing ratio is set to less than 50% by mass so as not to cause a significant decrease in the catalytic activity of the granular material (f).

As shown in FIG. 2, a mixed gas (g), which is a fluidizing gas of a fluidized medium, is supplied from the lower part of the fluidized bed reactor and blown upward from the gas dispersion plate 10 to form the fluidized bed 4. The flow rate of the mixed gas (g) blown out from the gas dispersion plate 10 is only required to maintain a good dispersion state, and is usually about 0.05 to 2 m / sec. If it is less than 0.05 m / sec, the fluidity decreases. On the other hand, if the flow rate exceeds 2 m / sec, there is no problem in fluidity, but the flow rate of the gas (g _p ) discharged from the fluidized bed reactor 1 increases, and the scattering amount of the fluidized medium increases, resulting in a cyclone or the like. Not only the load of the dust collector becomes excessive, but also the particle size of the solid organic material when the solid organic material is supplied from the upper part of the reactor needs to be increased as described later, so that the reaction efficiency is lowered.

  As for the method of supplying the organic substance into the fluidized bed reactor 1, the liquid organic substance such as oil-containing sludge or waste oil may be sprayed by a spray nozzle or the like, and the supply position may be the upper part of the fluidized bed reactor 1 or gas dispersion. Any position such as the upper part of the plate 10 may be used. On the other hand, in the case of a solid organic material such as plastic or biomass, it is common to supply from the upper part of the fluidized bed reactor 1, but a part of the mixed gas (g) is branched and mixed gas (g) It is also possible to supply the upper part of the gas dispersion plate 10 by pneumatic transportation. In addition, when supplying a solid organic substance from the upper part of the fluidized bed reactor 1, it is easier to drop by gravity rather than supplying by pneumatic transportation. However, in that case, it is preferable to mold the supplied solid organic material so that the particle size and density do not scatter, and to select a particle size that does not reduce the reaction efficiency.

Note that in the present invention, organic substances such as plastics are reduced in molecular weight and the number of molecules is increased by about twice, so that the flow rate of the product gas in the reactor is about twice that of the mixed gas (g). It is necessary. For example, if the flow rate of the mixed gas (g) is 0.05 m / sec, the flow rate of the product gas is about 0.1 m / sec. Therefore, the true density of the solid organic substance is preferably 1 g / cm ^3. The particle size is about 2 to 6 mm. Moreover, if the flow rate of the mixed gas (g) is 2 m / sec, the flow rate of the product gas is about 4 m / sec. Therefore, when the true density of the organic substance is 1 g / cm ³ , the preferred particle size is 15 to It is about 20 mm.

The gasified product (gas product) of the organic substance obtained by the method of the present invention is usually light hydrocarbons of CO and C1 to C4, and is suitable as a gaseous fuel. Moreover, a part can be condensed and it can also be set as a liquid fuel.
The LHV in the gaseous fuel is about 6 to 10 Mcal / Nm ^3, which is the same as natural gas. Nevertheless, since the carbon monoxide concentration is high, it is characterized by higher combustibility than natural gas. Because of its high carbon monoxide concentration and high combustibility, it is safer to use it as a city gas alternative fuel in factories with metallurgical furnaces such as steelworks than to supply it as household city gas. preferable.

  Further, the gas product obtained by the method of the present invention can be used not as a fuel but as a reducing material such as a blast furnace. As mentioned above, this gas product mainly consists of light hydrocarbons and carbon monoxide, which are natural gas components, but both natural gas and carbon monoxide are effective as reducing materials for iron ore, so in blast furnace operation, By blowing the gas product obtained by the method of the present invention from the tuyere of a blast furnace, the amount of coke used as a reducing material can be reduced, which is effective in reducing carbon dioxide emissions and iron manufacturing costs.

[Example 1]
A branch pipe for a laboratory test is provided in the gas discharge pipe of the gas holder for temporarily storing the converter gas, and a small flow rate of the converter gas can be extracted through the branch pipe. Downstream of this branch pipe are a flow control valve, a steam mixer, a preheater (for mixed gas of converter gas and steam), a fixed bed shift reactor (inner diameter 30 mm), and an externally heated fluidized bed reactor (inner diameter 44 mm). ) Were arranged in this order. Piping is connected so that the total amount of shift reaction product gas can be supplied from the bottom of the fluidized bed reactor, and a circle feeder type quantitative charging device is provided so that waste plastic can be dropped into the reactor from the top of the fluidized bed reactor. Was installed. From the upper part of the fluidized bed reactor, a product sampling port was connected via a cyclone as a first stage dust collector, a gas filter as a second stage dust collector, and a gas cooler. Since the cyclone dipleg is not inserted into the fluidized bed reactor, the fluid medium (catalyst) is not circulated in this embodiment.

The average composition of the converter gas in the gas _{holder, H 2: 12vol%, CO} : 54vol%, CO 2: 17vol%, H 2 O: 1vol%, N 2: was 16 vol%. The steam mixer was supplied with 74 NL / h of the converter gas and 100 NL / h of steam at a pressure of 10 kg / cm ² G as steam, and the temperature was raised to 320 ° C. with a preheater, and then the shift reactor (Fe-Cr system) High temperature shift catalyst filling). Due to the shift reaction in the shift reactor, gas having a gas composition of H ₂ : 26 vol%, CO: ₂ vol%, CO ₂ : 28 vol%, H ₂ O: 37 vol%, N ₂ : 7 vol% (shift reaction product gas) Obtained. This shift reaction product gas had a flow rate of 172 NL / h (170 g / h in mass flow rate) and a reactor outlet gas temperature of 430 ° C.

A gas dispersion plate is provided in the lower part of the externally heated fluidized bed reactor, which is a reforming reactor for reducing the molecular weight of organic substances. The fluid dispersion medium (catalyst) is used as a fluid medium (catalyst) above the gas dispersion plate. Generated converter dust coarse particles (T-Fe: 80% by mass, average particle size: 80 μm, true density: 5.9 g / cm ³ , bulk density 2.9 g / cm ³ , Al ₂ O ₃ content 0.38 After charging 1 kg of (mass%), nitrogen gas was supplied at 50 NL / h to fluidize the converter dust. The fluidized bed height was about 280 mm (Lf / D = 6.4).

Next, after heating the fluidized bed reactor at a set temperature of 800 ° C., the fluidizing gas was switched from nitrogen to the shift reaction product gas (flow rate: 172 NL / h, flow rate at 800 ° C .: 0.12 m / sec). Next, a model waste plastic obtained by mixing 3.3% by mass of Al ₂ O ₃ (ash model material) with polyethylene into a particle size of 4 mm and a bulk density of 0.4 g / cm ³ is 910 g / h (880 g as polyethylene content) / H, Al ₂ O ₃ minutes at 30 g / h), and after continuing the low molecular weight reaction of the waste plastic for 1 hour, the gaseous fuel is calculated from the gas analysis results after cooling by the gas cooler. The amount was determined from the analysis results of the liquid products collected in the liquid fuel collector installed at the lower part of the gas cooler, and the production amount, composition, and LHV (low combustion heat) were obtained. The results are shown in Table 1.

  Since the total amount of shift reaction product gas and polyethylene supplied as raw materials is 1050 g / h, the production rate with respect to the total amount of feed materials is 36% for gaseous fuel (defined as products from H2 to C4), and liquid fuel (C5 62% was defined as the above product). Since it is difficult to directly measure the amount of unreacted polyethylene, the total yield of gaseous fuel (380 g / h) and liquid fuel (650 g / h) with respect to the total amount of shift reaction product gas and polyethylene (1050 g / h) supplied. Is defined as the polyethylene degradation rate, the polyethylene degradation rate was calculated to be 98% in this invention example.

While the reaction was continued, the temperature in the reactor, which was the fluidized bed portion, was about 796 ° C., which was about 4 ° C. lower than the set temperature, but there were no troubles such as fusion or blockage of polyethylene. After the experiment was completed, the reactor was disassembled and the inside was observed, but no formation of carbide was observed, and it was confirmed that a stable molecular weight reduction reaction could be performed by the fluidized bed. About 20 g of solid was recovered from the cyclone dipleg at the end of the experiment. When the recovered solid was analyzed, the Al ₂ O ₃ content was 0.42 wt% (0.084 g as the amount of Al ₂ O ₃ ). On the other hand, the solid collected by the gas filter which is a 2nd stage dust collector was about 26g. When the collected solid was analyzed, the Al ₂ O ₃ content was 99.6% by weight (25.9 g as the amount of Al ₂ O ₃ ), and the Fe content was below the detection limit. Considering experimental errors, it is considered that Al ₂ O ₃ which is a model ash and fluid medium (coarse dust) are almost completely separated.

[Comparative Example 1]
The low molecular weight reaction test of polyethylene was conducted in the same manner as in Example 1 except that the reactor was filled with a catalyst in which converter dust coarse particles were molded to a particle size of 4 mm. In this test, as a result of setting the catalyst particle size to 4 mm, the catalyst was not fluidized, and therefore the reaction was carried out in a flow-through fixed bed reactor.
The reaction was stopped because the temperature in the reactor gradually decreased from the start of the polyethylene supply, and the reactor pressure increased, making it difficult to supply the shift reaction product gas.
When the reactor was disassembled and the inside was observed, the catalyst layer was clogged with a substance that was considered to be a polyethylene fusion product, and unlike a fluidized bed, a flow-through fixed bed reactor could stably perform a low molecular weight reaction. It was confirmed that it was very difficult to do.

[Comparative Example 2]
Example 1 except that blast furnace dust (T-Fe: 45% by mass, Al ₂ O ₃ content: 2% by mass, true density: 3 g / cm ³ , average particle size: 400 μm) was used as a fluid medium (catalyst). Similarly, a molecular weight reduction reaction test of Al ₂ O ₃ -containing polyethylene was performed.
As a result of the low molecular weight reaction test, there was no problem with the fluidized state, polyethylene fusion and clogging as in Example 1, but the solid density recovered from the cyclone was very small because the true density of the fluidized medium was low. Most solids (Al ₂ O ₃ which is blast furnace dust and model ash) were collected by a gas filter, and model ash and blast furnace dust could hardly be separated.

[Example 2]
Industrial waste plastic and construction waste wood from which foreign materials such as metal have been removed are crushed by a crusher equipped with a screen with a mesh opening of 10 mm, and the crushed waste plastic and construction waste wood are The mixture was put into a ring die type compression molding granulator at a ratio of 7 parts by mass of waste plastic and 3 parts by mass of construction waste wood to obtain a mixed molded product. The compression molding granulator is equipped with a die ring having a plurality of die holes (φ6 mm) penetrating the entire circumference, and a mixture of waste plastic and construction waste wood is compressed and extruded from the die hole of the die ring. Is obtained.

The low molecular weight reduction reaction test of the mixed molded product of waste plastic and waste wood was conducted in the same manner as in Example 1 except that the mixed molded product was supplied to the fluidized bed reactor and the set temperature of the fluidized bed reactor was set to 600 ° C. went.
Analysis of the low molecular weight reaction product, the gaseous fuel generation rate 38%, the composition of the gaseous _{fuel, CO: 65vol%, N 2} : 5vol%, C1~C2: 9vol%, C3~C4: 21vol% ( H2, CO ₂ and H ₂ O were all 0 vol%), LHV was 8.5 Mcal / Nm ³ , and the liquid fuel production rate was 60%. During the reaction, there was no trouble such as plastic fusing or clogging in the fluidized bed reactor, and the low molecular weight reaction could be performed stably. Furthermore, the ash content in the mixed molded product was collected almost quantitatively by the gas filter which is the second stage dust collector, and there was no problem in separating the actual ash content and the fluid medium (coarse dust).

DESCRIPTION OF SYMBOLS 1 Fluidized bed reactor 2 Discharge pipe 3a Primary dust collector 3b Secondary dust collector 4 Fluidized bed 5 Return pipe 6 Die ring 7 Rolling roller 8 Cutting blade 10 Dispersing plate 11 Wind box part 60 Die hole

Claims (5)

By adding excess water vapor to the exhaust gas (g ₀ ) containing carbon monoxide generated in the metallurgical furnace to cause the shift reaction, hydrogen and carbon dioxide generated by the shift reaction were not consumed in the shift reaction. In a method of making a mixed gas (g) containing water vapor and bringing the mixed gas (g) into contact with an organic substance and modifying the organic substance to reduce the molecular weight,
In a fluidized bed having a true density of 4 to 8 g / cm ³ and containing a granular material (f) containing at least one selected from Fe, Ni, and Cr as a fluidized medium, a mixed gas (g) A method for reducing the molecular weight of an organic material by contacting the organic material and modifying the organic material to reduce the molecular weight.
At least a part of the powder (f) is iron-containing dust generated in the steelmaking process ,
A method for reducing the molecular weight of an organic substance, wherein at least a part of the organic substance to be modified is a mixed molded product of plastic and wood .   The method for reducing the molecular weight of an organic substance according to claim 1, wherein the powder (f) is iron-containing dust generated in a steelmaking process. The method for reducing the molecular weight of an organic substance according to claim 1 or 2 , wherein the wood is at least one selected from construction waste wood, packaging / transport waste wood, and thinned wood. The gas (g _p ) discharged from the fluidized bed is passed through a dust collector, the fluid medium contained in the gas (g _p ) is collected, and the collected fluid medium is circulated through the fluidized bed. The method for reducing the molecular weight of an organic substance according to any one of claims 1 to 3 . A method for operating a blast furnace, wherein a gas product generated by reducing the molecular weight of an organic substance by the method according to any one of claims 1 to 4 is blown into the blast furnace.

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