JP6248987B2 - 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 the organic substance such as plastic into a gaseous fuel or the like.

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.
Furthermore, in Patent Document 4, hydrogen and carbon dioxide generated by the shift reaction are added to the shift reaction by adding excess water vapor to the exhaust gas containing carbon monoxide generated in the metallurgical furnace to cause the shift reaction. A method is disclosed in which a mixed gas containing water vapor that has not been consumed is brought into contact with an organic substance to reduce the molecular weight.

JP 2007-224206 A JP 2010-013657 A JP 2001-131560 A JP 2012-188641 A

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.
The method of Patent Document 4 is an excellent method capable of efficiently reducing the molecular weight of organic substances under unprecedented mild reaction conditions of about 400 to 900 ° C. under normal pressure, but uses a metallurgical furnace generated exhaust gas as a raw material gas. Therefore, there are restrictions on the installation location of the low molecular weight reaction equipment.

  Accordingly, an object of the present invention is to efficiently reduce the molecular weight of an organic substance to obtain a high-quality, high-calorie modified product, and to reduce the amount of carbon monoxide-containing gas introduced from outside the system for the shift reaction. Alternatively, a method for reducing the molecular weight of an organic substance that can be a self-supporting process that does not substantially introduce carbon monoxide-containing gas from outside the system, thereby reducing or eliminating restrictions on the installation location of equipment. Is to provide.

In order to solve the problems of the prior art as described above, the present inventors have studied based on the idea of using a gas generated in the system as a carbon monoxide-containing gas for a shift reaction. As a result, a new method has been devised in which a gas product produced by reducing the molecular weight of an organic substance is steam reformed to produce a carbon monoxide-containing gas, and this gas is used as a carbon monoxide-containing gas for shift reactions. did.
That is, this invention makes the following a summary.

[1] A shift reaction is performed by adding excess water vapor to a gas (g ₀ ) containing carbon monoxide having a carbon monoxide concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less to cause a shift reaction. A mixed gas (g) containing the generated hydrogen and carbon dioxide gas and water vapor not consumed in the shift reaction is brought into contact with the organic substance, and the organic substance is modified to reduce the molecular weight. In this method, a gas containing carbon monoxide is generated by adding steam to a part of a gas product generated by lowering the molecular weight of an organic substance and performing a steam reforming reaction (A). A method for reducing the molecular weight of an organic substance, wherein the gas is used as a gas (g ₀ ) containing carbon monoxide.
[2] In the method for reducing the molecular weight according to [1], the gas (g ₀ ) containing carbon monoxide has a carbon monoxide concentration of 10 vol% or more and a nitrogen concentration of 55 vol% or less. A method for reducing the molecular weight of a substance.

[3] In the method for reducing the molecular weight according to [1] or [2] above, a blast furnace gas is used as a gas (g ₀ ) containing carbon monoxide at the start of operation, and monoxide is oxidized except at the start of operation. A method for reducing the molecular weight of an organic substance, characterized in that a gas containing carbon monoxide generated by a steam reforming reaction (A) is used as at least a part of a gas (g ₀ ) containing carbon.
[4] In the method for reducing the molecular weight according to any one of [1] to [3], the gas is generated in the steam reforming reaction (A) as a gas (g ₀ ) containing carbon monoxide except when the operation is started. A method for reducing the molecular weight of an organic substance, characterized by using only a gas containing carbon monoxide.

  According to the present invention, when a high molecular weight organic substance such as waste plastic is reduced in molecular weight to be converted into gaseous fuel or liquid fuel, the organic substance is efficiently reformed to reduce the molecular weight, and the heavy component or carbon It is possible to obtain a high-calorie reformed product with a low quality and a large amount of light components, as well as a gas generated in the system as a carbon monoxide-containing gas used in the shift reaction (produced by lowering the molecular weight of organic substances Gas generated by steam reforming a part of the gaseous fuel), the amount of carbon monoxide-containing gas introduced from outside the system for the shift reaction is reduced, or the monoxide from outside the system is substantially reduced. A self-supporting process in which no carbon-containing gas is introduced can be achieved, and therefore, restrictions on the installation location of equipment can be reduced or eliminated. In addition, carbon monoxide-containing gas such as blast furnace-generated exhaust gas introduced from outside the system contains a considerable amount of nitrogen, but the gas generated inside the system (one of the gaseous fuels generated by low molecular weight organic substances). By using the gas generated by steam reforming the part) for the shift reaction, the nitrogen concentration in the system can be lowered and the reactivity can be improved.

Also, with regard to the implementation equipment, there is no need for special measuring instruments or flow path switching valves, and the organic substance can be reformed even at a relatively low reaction temperature. it can.
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.

Explanatory drawing which shows typically an example of the low molecular-weight equipment provided for implementation of this invention In an Example, the graph which showed the time-dependent change from the time of an operation start to a steady operation about LHV of the gaseous product produced | generated by low molecular weight of an organic substance In the Examples, a graph showing the change over time from the start of operation to the steady operation with respect to the nitrogen concentration of the gaseous product generated by reducing the molecular weight of the organic substance.

In the method for reducing the molecular weight of an organic substance of the present invention, a gas containing carbon monoxide having a carbon monoxide concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less (g ₀ ) (hereinafter referred to as “carbon monoxide-containing gas ( g ₀ ) ")) by adding an excess of water vapor to cause a shift reaction (reaction [1]) to produce hydrogen and carbon dioxide gas produced by the shift reaction and water vapor not consumed in the shift reaction. A mixed gas (g), and this mixed gas (g) is brought into contact with an organic substance, and the organic substance is modified to reduce the molecular weight (reaction [2]). A gas containing carbon monoxide (hereinafter referred to as “carbon monoxide-containing gas (g)” is obtained by adding steam to a part of the generated gas product and performing a steam reforming reaction (A) (reaction [3]). ₁₀₎ "or as" gas (g ₁₀₎ ".) to produce a, this gas g ₁₀₎ is to use as the shift reaction (reaction [1]) for carbon monoxide-containing gas (g _0).
Note that adding excess water vapor to the carbon monoxide-containing gas (g ₀ ) means adding water vapor so that excess water vapor that is not consumed in the shift reaction remains in the mixed gas (g).

反応［3］：ＣＨ_４＋Ｈ_２Ｏ→ＣＯ＋３Ｈ_２ The above reaction [1] (shift reaction), reaction [2] (reduction in molecular weight), and reaction [3] (steam reforming reaction) are the reactions shown below. In addition, reaction [3] showed the steam reforming reaction of methane as an example.
Reaction [1]: CO + H ₂ O → H ₂ + CO ₂

Reaction [3]: CH ₄ + H ₂ O → CO + 3H ₂

In the reaction [1], excess water vapor is added to the carbon monoxide-containing gas (g ₀ ), so the mixed gas (g) after the shift reaction is excessively added with H ₂ and CO ₂ generated by the shift reaction. Minute H ₂ O will be included. Here, each 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 carbon monoxide containing gas (g ₀ ) and the reaction rate of the shift reaction. And a mixed gas (g) for organic substance modification. 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 general method is to reduce the shift reactor length or reduce the catalyst loading.

The mixed gas (g) for organic substance modification obtained by the shift reaction contains water vapor, hydrogen and carbon dioxide gas, and there are no special restrictions on their concentrations, but the decomposition rate of organic substances such as waste plastics On the other hand, the water vapor concentration is preferably 5 to 70 vol% from the viewpoint of suppressing CO ₂ residue in the reforming reaction product gas. 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. From the same viewpoint, the more preferable composition of the mixed gas (g) is water vapor concentration: 20 to 70 vol%, hydrogen concentration: 10 to 40 vol%, carbon dioxide concentration: 10 to 40 vol%. In addition, it does not prevent that other gas components (for example, nitrogen etc.) are contained in this mixed gas (g).

Reaction [2] (reduction in molecular weight) is thought to involve four reactions of hydrogenation, hydrocracking, steam reforming, and carbon dioxide reforming at the same time. In addition, it is considered that the thermal decomposition reaction proceeds at the same time, the organic substance is reduced in molecular weight, and is a complex reaction in which various light hydrocarbons and carbon monoxide are generated. Here, the hydrogenation reaction includes a methanation reaction by hydrogen addition to CO or CO ₂ in addition to a hydrogen addition reaction to an unsaturated bond. In this reaction [2], the reduction of the molecular weight of the organic substance is promoted efficiently 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 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. Coal, etc., and one or more of these can be targeted.
The reaction temperature at the time of modifying the organic material is preferably 400 to 900 ° C. In this temperature range, a more suitable reaction temperature may be selected according to the type of the organic material.

The gaseous product produced by the reaction [2] is recovered and used as a gaseous fuel. In the present invention, a part of the gaseous product produced by the reaction [2] is separated and steam is added thereto. Reaction [3] (steam reforming reaction (A)) is performed to generate a carbon monoxide-containing gas (g ₁₀ ), and this gas (g ₁₀ ) is used for the shift reaction (reaction [1]). Used as a carbon oxide-containing gas (g ₀ ).

The conditions of reaction [3] (steam reforming reaction (A)) are not limited at all, but the reaction temperature when using a Ni-based steam reforming catalyst is preferably about 600 to 900 ° C., and no catalyst is used. In this case, the reaction temperature is preferably about 700 to 1000 ° C. The amount of steam added is 1 to 5 moles compared to the total amount of carbon atoms contained in the gas product produced in reaction [2] (low molecular weight reaction) supplied to the steam reforming reactor. Preferably, it is more preferably 1 times mol or more and 3 times mol or less. The method for adding steam is arbitrary, and may be supplied to the steam reforming reactor separately from the gas product, or may be supplied to the steam reforming reactor after mixing the gas product and steam. . As described above, since the steam reforming reaction has a higher temperature than the shift reaction, it is preferable to install a heat exchanger or the like for cooling the product gas after steam reforming downstream of the steam reforming reactor.
Here, in a steady state operation, only the gas (g ₁₀₎ may be used as a carbon monoxide-containing gas for the shift reaction (g _0), carbon monoxide-containing gas shift reaction (g ₀₎ A gas (g ₁₀ ) may be used as a part, and the remainder may be a carbon monoxide-containing gas introduced from outside the system (outside of the process).

On the other hand, in any case, when the operation is started (when the process consisting of reaction [1] to reaction [3] is started), a carbon monoxide-containing gas (carbon monoxide) introduced from outside the system (outside the process) A carbon monoxide-containing gas having a concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less is used as the carbon monoxide-containing gas (g ₀ ) for the shift reaction.
When using carbon monoxide-containing gas introduced from outside the system (outside of the process) as a carbon monoxide-containing gas (g ₀ ) for shift reaction, the purchased pure carbon monoxide gas or carbon monoxide-containing gas is externally connected via a pipeline. LNG, LPG, naphtha, etc. are procured in addition to the method of supplying directly from the tank and the method of supplying from the cardle cylinder, and the LNG, LPG, naphtha, etc. are procured and supplied to the steam reforming reactor for carrying out the reaction [3] of the present invention. It can also be converted to a carbon oxide-containing gas.

At the start of operation, a blast furnace gas, a shaft furnace gas, or a mixed gas containing hydrogen, carbon dioxide gas and water vapor is introduced from outside the system (outside of the process), and this is mixed with a mixed gas (g ). When a mixed gas introduced from outside the system (outside of the process) is used as a mixed gas (g) for organic substance reforming, the purchased pure carbon dioxide and pure hydrogen, or a gas containing carbon dioxide and hydrogen is supplied through a pipeline. It is possible to adopt a method of supplying water vapor directly to the external supply.
In addition, carbon monoxide-containing gas and mixed gas are introduced from outside the system (outside of the process) at the start of operation when the equipment is started up. However, after that, carbon monoxide-containing gas and mixed gas are mixed before the steady operation is stopped. The gas may be temporarily stored in a holder and used at the time of activation.

The carbon monoxide-containing gas (g ₀ ) used for the shift reaction in the present invention preferably has a carbon monoxide concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less, and a carbon monoxide concentration of 10 vol% or more, The nitrogen concentration is particularly preferably 55 vol% or less. Here, the carbon monoxide-containing gas (g ₀ ) used for the shift reaction is introduced from outside the system (outside the process) in addition to the carbon monoxide-containing gas (g ₁₀ ) generated by the steam reforming reaction (A). Carbon monoxide-containing gas used as carbon monoxide-containing gas (g ₀ ) is also included. If the carbon monoxide concentration of the gas containing carbon monoxide (g ₀ ) is less than 5 vol%, the carbon dioxide concentration after the shift reaction will be low, and the gas fuel after the reforming reaction will be less caloric than hydrocarbons or carbon monoxide. Hydrogen, which is a gas component, tends to remain. Moreover, when nitrogen concentration exceeds 60 vol%, while the fall of LHV of gaseous fuel will become remarkable, shift reaction rate will also fall.

As the carbon monoxide-containing gas supplied from outside the system (outside of the process) for use as a carbon monoxide-containing gas (g ₀ ) for shift reaction, particularly from the viewpoint of the above-mentioned preferred gas composition, shaft furnace gas (typical gas composition _{CO: 10~30vol%, CO 2:} 10~30vol%, N 2: 55~30vol%, H 2: 0~10vol%) are preferred. In addition, other carbon monoxide-containing gases may be used as long as the composition is within the preferred range of the present invention. For example, exhaust gas discharged from a general combustion furnace, exhaust gas discharged from a thermal power plant, metallurgical furnace generated exhaust gas such as converter gas, etc. can be exemplified, and one or more of these are oxidized Carbon-containing gas can also be used.

In the present invention, when constructing a self-supporting process in which carbon monoxide-containing gas is not introduced from outside the system except when the operation is started, the amount of gas product used for performing the reaction [3] (steam reforming reaction (A)) is The amount of the gas product produced in the reaction [2] (reduction in molecular weight) is preferably 5% by mass or more, more preferably 10% by mass or more. When the amount of gas product used to carry out reaction [3] is less than 5% by mass of the amount of gas product produced in reaction [2], the amount of gas product after the steam reforming reaction contains carbon monoxide used as a raw material. Less than gas (g ₀ ), the reaction [2] is not promoted sufficiently, which is not preferable. When the amount of gaseous product used to carry out reaction [3] is large, the reaction rate of reaction [2] increases, but as the amount of use increases, not only the amount of gaseous fuel obtained as a product decreases, but also the gas The LHV increase effect of the fuel is also reduced, which is uneconomical. Therefore, there is no theoretical upper limit of the amount of gas product used for carrying out the reaction [3], but in practice, it is preferably 50% by mass or less, and preferably 40% by mass or less of the amount of gas product produced in the reaction [2]. More preferable.

FIG. 1 schematically shows a facility for reducing the molecular weight of an organic substance used in the practice of the present invention. 1 is a mixed gas (g) by a shift reaction between a carbon monoxide-containing gas (g ₀ ) and water vapor. 2 is a reforming reactor that reforms an organic substance with the mixed gas (g) obtained in the shift reactor 1 to lower the molecular weight, and 3 is a gas generated in the reforming reactor 2 It is a steam reforming reactor in which a part of the product is steam reformed to generate a carbon monoxide-containing gas (g ₁₀ ). Also, 4 is a liquid product collector that collects and separates liquid products from products generated by reducing the molecular weight of organic substances in the reforming reactor 2, and 5 is a gas generated in the reforming reactor 2. It is a gas cooler that cools the product, and a part of the gas product discharged from the gas cooler 5 is supplied to the steam reforming reactor 3 through the pipe 11. On the other hand, the remaining gaseous product is taken out of the system through the pipe 12 for use as gaseous fuel. The pipe 11 is provided with a flow control valve 13.

Reference numeral 7 denotes a supply pipe for supplying the carbon monoxide-containing gas (g ₁₀ ) generated in the steam reforming reactor 3 to the shift reactor 1 as a carbon monoxide-containing gas (g ₀ ) for shift reaction. The supply pipe 7 is provided with a heat exchanger 6 for cooling the carbon monoxide-containing gas (g ₁₀ ) discharged from the steam reforming reactor 3.
The shift reactor 1 may be a known one such as a fixed bed reactor packed with a catalyst. A supply pipe 14 for supplying gas (gas introduced from outside the system) to the shift reactor 1 has flow rate control valves 8a and 8b that can adjust the supply amounts of carbon monoxide-containing gas (g ₀ ) and steam, respectively. steam mixer 9 for mixing the steam to carbon oxide-containing gas (g _0), preheater 10 for preheating the carbon monoxide-containing gas and (g ₀₎ of the mixed gas of steam is provided.

  The reforming reactor 2 includes, for example, a moving bed type reactor such as an externally heated rotary kiln, a fluidized bed type reactor, a fixed bed type reactor, and the like. A catalyst is not particularly required for reforming the organic substance, but the reaction may be carried out by filling the catalyst. As the catalyst, one or more kinds of catalysts each having steam reforming activity, carbon dioxide reforming activity, hydrogenation activity, and hydrocracking activity can be used. Specific examples include Ni-based reforming catalysts, Ni-based hydrogenation catalysts, Pt / zeolite-based petroleum refining catalysts, and the like. Also, converter-generated dust, which is known to be composed of fine Fe particles, can be used as a reforming catalyst or a hydrocracking catalyst. On the inlet side of the reforming reactor 2, a quantitative charging device (not shown) of an organic substance (waste plastic or the like) by a screw conveyor system or the like is installed.

The steam reforming reactor 3 is not particularly limited, but generally a fixed bed flow reactor filled with a catalyst is used. Since the steam reforming reaction is a large endothermic reaction, it is necessary to use an external heating type or internal heating type reactor, but there is no special restriction on the heating method, and heating is performed outside the tubular reaction tube. A known method such as a type in which a furnace is installed can be used.
In addition, a sampling port and a flow meter (both not shown) are installed on the outlet side pipe of the shift reactor 1 and the outlet side pipe of the gas cooler 5 after cooling, so that the shift reaction product gas and the gas product are installed. Quantitative analysis is possible.

In the operation of the facility shown in FIG. 1, when the operation is started, a gas in which excess steam is added to the carbon monoxide-containing gas (g ₀ ) from outside the system (outside of the process) is supplied to the shift reactor 1 through the supply pipe 14. Shift reaction. The mixed gas (g) after the shift reaction contains hydrogen and carbon dioxide generated by the shift reaction, and water vapor not consumed in the shift reaction. The reforming reactor 2 is supplied with the mixed gas (g) and the organic substance, and the mixed substance (g) is brought into contact with the organic substance to reform the organic substance to reduce the molecular weight. Products resulting from molecular weight reduction of organic materials are gaseous products (carbon monoxide, C1-C4 hydrocarbons, etc.) and liquid products.

The liquid product is collected and separated by the liquid product collector 4 from the product (gas product, liquid product) resulting from the low molecular weight organic material, and the gas product is sent to the gas cooler 5 for cooling. Is done. A part of the gaseous product exiting the gas cooler 5 is supplied to the steam reforming reactor 3 through the pipe 11 and the flow rate control valve 13, and the rest is discharged out of the system through the pipe 12 and used as gaseous fuel. The Steam is supplied to the steam reforming reactor 3, and the gas product is steam reformed to generate a carbon monoxide-containing gas (g ₁₀ ). This carbon monoxide-containing gas (g ₁₀ ) is supplied to the shift reactor 1 through the supply pipe 7 while being cooled by the heat exchanger 6 and used as a carbon monoxide-containing gas (g ₀ ) for the shift reaction. Is done.

As described above, during the steady operation, only the carbon monoxide-containing gas (g ₁₀ ) supplied from the steam reforming reactor 3 is used as the carbon monoxide-containing gas (g ₀ ) for the shift reaction. Alternatively, the carbon monoxide-containing gas (g ₁₀ ) supplied from the steam reforming reactor 3 is used as a part of the carbon monoxide-containing gas (g ₀ ) for the shift reaction, and the rest is outside the system (outside of the process). Carbon monoxide-containing gas introduced from (1) may be used. Therefore, in the former case, only steam is supplied to the shift reactor 1 through the supply pipe 14. On the other hand, in the latter case, what is supplied to the shift reactor 1 through the supply pipe 14 is a gas obtained by adding steam to a carbon monoxide-containing gas (g ₀ ) introduced from outside the system (outside of the process). However, the amount of carbon monoxide-containing gas (g ₀ ) introduced from outside the system (outside of the process) is reduced by the amount of carbon monoxide-containing gas (g ₁₀ ) supplied from the steam reforming reactor 3. The control of the gas supply amount through the supply pipe 14 as described above is performed by the flow rate control valves 8a and 8b.

The equipment having the apparatus configuration as shown in FIG. 1 was used to modify (decrease in molecular weight) the waste plastics corresponding to the start-up and the steady operation. In this facility, an external heating fluidized bed reactor was used as the reforming reactor 2.
First, the modification (reduction in molecular weight) of waste plastic corresponding to the start of operation was performed as follows.
The average composition of the carbon monoxide-containing gas (g ₀ ) supplied from outside the system (outside of the process) is a gas composition corresponding to the blast furnace gas: H ₂ : 4 vol%, CO: 23 vol%, CO ₂ : 23 vol%, H _{2 O: 0vol%, N 2} : it was 50 vol%. A carbon monoxide-containing gas (g ₀ ) is supplied to the steam mixer 9 at 74 Nm ³ / h, and steam at a pressure of 10 kg / cm ² G is supplied as 67 Nm ³ / h, and this mixed gas is introduced into the shift reactor 1. Gas mixture is H ₂ : 14 vol%, CO: 0 vol%, CO ₂ : 24 vol%, H ₂ O: 35 vol%, N ₂ : 27 vol% (gase of shift reaction) Gas) was obtained. The mixed gas (g) had a flow rate of 141 Nm ³ / h (mass flow rate of 155 kg / h) and a shift reactor outlet gas temperature of 306 ° C.

The externally heated fluidized bed reactor which is the reforming reactor 2 is preheated to 500 ° C. in advance, and the mixed gas (g) (shift reaction product gas) is introduced into the reforming reactor 2, Polyethylene that was crushed into granules as a model material of waste plastic was supplied at 880 kg / h, and the temperature was raised to 800 ° C., which is the planned reaction temperature. After reaching 800 ° C., the liquid product collected in the liquid product collector 4 was discharged, and then the reforming reaction of the waste plastic was continued for 1 hour.
From the gas analysis result after cooling by the gas cooler 5, the liquid product content from the reforming reactor 2 is the same as the liquid product collected in the liquid product collector 4. From the analysis results, the production amount and the composition were obtained, respectively, and the LHV was obtained for the gas product. The results are shown in Table 1.

Next, waste plastic modification (reduction in molecular weight) corresponding to the steady operation was performed as follows.
A part of the gas product (gas product shown in Table 1) from the reforming reactor 2 is introduced into the 27.8 kg / h (20.8 Nm ³ / h) steam reforming reactor 3, and this steam Water vapor was added to the reforming reactor 3 to perform a steam reforming reaction to generate a carbon monoxide-containing gas (g ₁₀ ). Therefore, 7.3 mass% of the gaseous fuel shown in Table 1 was introduced into the steam reforming reactor 3 and used for the generation of carbon monoxide-containing gas (g ₁₀ ). The addition amount of water vapor was 20 kg / h (25 Nm ³ / h). After the carbon monoxide-containing gas (g ₁₀ ) obtained by this steam reforming is cooled to 407 ° C. by the heat exchanger 6, it is introduced into the shift reactor 1 through the supply pipe 7, and further steam is added to perform the shift reaction. Went. In addition, the addition amount of water vapor | steam was 14 kg / h (17Nm < ³ > / h). The mixed gas (g) obtained by this shift reaction was introduced into the reforming reactor 2 (externally heated fluidized bed reactor). This reforming reactor 2 was supplied with 880 kg / h of polyethylene that had been crushed into granules as a model material of waste plastic, and the temperature was raised to 800 ° C., which is the planned reaction temperature. After reaching 800 ° C., the liquid product collected in the liquid product collector 4 was discharged, and then the reforming reaction of the waste plastic was continued for 1 hour.
The gas product from the reforming reactor 2 is analyzed from the gas analysis result after cooling by the gas cooler 5, and the liquid product is similarly analyzed from the liquid product collected in the liquid product collector 4. From the results, the production amount and the composition were obtained, respectively, and LHV was obtained for the gas product. The results are shown in Table 2.

According to Table 2, the LHV of the generated gas product was 7.0 Mcal / Nm ^3, which was higher than that of the gas product (5.0 Mcal / Nm ³ ) at the start of operation shown in Table 1. Moreover, the nitrogen concentration of the produced | generated gas product was 4 vol%, and was low compared with the nitrogen concentration at the time of the operation start-up shown in Table 1 (25 vol%).
With respect to the LHV of the gas product generated in the reforming reactor 2, the change over time from the start of operation to the steady operation is shown in FIG. Moreover, about the nitrogen concentration of the gaseous product produced | generated by the reforming reactor 2, the time-dependent change from the time of operation start to steady operation is shown in FIG.

DESCRIPTION OF SYMBOLS 1 Shift reactor 2 Reforming reactor 3 Steam reforming reactor 4 Liquid product collector 5 Gas cooler 6 Heat exchanger 7 Supply pipe 8a, 8b Flow control valve 9 Steam mixer 10 Preheater 11 Piping 12 Piping 13 Flow control valve 14 Supply pipe

Claims (7)

Hydrogen produced by the shift reaction by adding excess water vapor to a gas (g ₀ ) containing carbon monoxide having a carbon monoxide concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less to cause a shift reaction. And mixed gas (g) containing carbon dioxide gas and water vapor not consumed in the shift reaction, contacting the mixed gas (g) with an organic substance, and modifying the organic substance to reduce the molecular weight. And
A gas containing carbon monoxide is generated by adding water vapor to a part of the gas product generated by lowering the molecular weight of the organic substance and performing a steam reforming reaction (A) ,
At the start of operation, blast furnace gas is used as the gas (g ₀ ) containing carbon monoxide ,
An organic substance characterized by using a carbon monoxide-containing gas generated by the steam reforming reaction (A) as at least a part of the gas (g ₀ ) containing carbon monoxide, except at the start of operation. Of low molecular weight. 2. The method for reducing the molecular weight of an organic substance according to claim 1, wherein the gas (g ₀ ) containing carbon monoxide has a carbon monoxide concentration of 10 vol% or more and a nitrogen concentration of 55 vol% or less. Except during startup of the operation, as a gas (g ₀₎ containing carbon monoxide, according to claim 1 or 2, characterized in that use only gas containing carbon monoxide produced in the steam reforming reaction (A) (2) A method for reducing the molecular weight of an organic substance. Hydrogen produced by the shift reaction by adding excess water vapor to a gas (g ₀ ) containing carbon monoxide having a carbon monoxide concentration of 5 vol% or more and a nitrogen concentration of 60 vol% or less to cause a shift reaction. And a mixed gas (g) containing carbon dioxide gas and water vapor not consumed in the shift reaction. The mixed gas (g) is brought into contact with an organic substance, and the organic substance is reformed to have a low molecular weight and become a fuel. A fuel production method for obtaining a reformate,
A gas containing carbon monoxide is generated by adding water vapor to a part of the gas product generated by lowering the molecular weight of the organic substance and performing a steam reforming reaction (A) ,
At the start of operation, blast furnace gas is used as the gas (g ₀ ) containing carbon monoxide ,
Fuel production characterized by using carbon monoxide-containing gas produced in the steam reforming reaction (A) as at least part of the gas (g ₀ ) containing carbon monoxide except when the operation is started Method. The fuel production method according to claim 4 , wherein the gas (g ₀ ) containing carbon monoxide has a carbon monoxide concentration of 10 vol% or more and a nitrogen concentration of 55 vol% or less. Except during startup of the operation, as a gas (g ₀₎ containing carbon monoxide, according to claim 4 or 5, characterized in that use only gas containing carbon monoxide produced in the steam reforming reaction (A) The fuel manufacturing method as described in any one of Claims 1-3. Gas mixture containing carbon monoxide (g ₀ ) is allowed to perform a shift reaction by adding excess water vapor, and a mixed gas containing hydrogen and carbon dioxide gas generated by the shift reaction and water vapor not consumed in the shift reaction ( a shift reactor (1) to obtain g);
A reforming reactor (2) for bringing the mixed gas (g) supplied from the shift reactor (1) into contact with an organic substance and reforming the organic substance to reduce the molecular weight;
Liquid product collector (4) for collecting / separating liquid products from products (however, gaseous products and liquid products) generated by reducing the molecular weight of organic substances in the reforming reactor (2) When,
A gas cooler (5) for cooling the gaseous product exiting the liquid product collector (4);
A part of the gas product cooled by the gas cooler (5) is supplied, and a gas containing carbon monoxide is generated by adding steam to the gas product and performing a steam reforming reaction. A steam reforming reactor (3);
A facility for reducing the molecular weight of an organic substance, comprising a supply pipe (7) for supplying a gas containing carbon monoxide produced in the steam reforming reactor (3) to the shift reactor (1).

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