JP2021161253A - Fuel reforming method and fuel reforming device - Google Patents

Abstract

To provide a fuel reforming device capable of smoothly reforming waste containing carbon fiber reinforced plastic into fuel.SOLUTION: A fuel reforming device 100 includes: a heating unit 20 which heats waste containing carbon fiber reinforced plastic to a temperature range of 250-450°C in an atmosphere having an oxygen concentration of 13 volume% or less to reform the waste; a feed gas preparation unit 90 which prepares a feed gas adjusted to a predetermined oxygen concentration by using at least one gas selected from steam, carbon dioxide and nitrogen; and a decomposition gas combustion unit 60 which recovers and burns the decomposition gas generated in the heating unit 20.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a fuel reforming method and a fuel reforming device.

Carbon fiber reinforced plastic (CFRP) is used in various applications such as daily necessities, personal computers, home appliances, automobiles, aircraft, sports goods, and construction and civil engineering fields by utilizing the characteristics of carbon fiber such as light weight and high strength. The shredder dust generated by the disposal of these products contains carbon fiber reinforced plastic.

Carbon fiber reinforced plastics become easier to burn as they become finer. However, carbon fiber reinforced plastics are less likely to be crushed than other wastes and tend to maintain a large size. When waste containing CFRP having such a large size is used as fuel, carbon fibers may remain unburned. Therefore, for example, Patent Document 1 proposes a technique in which CFRP is heat-treated under predetermined conditions to improve the pulverizability of CFRP, and the pulverized product obtained by pulverizing the CFRP after the heat treatment is used as a fuel for a cement manufacturing apparatus. There is.

JP-A-2017-66383

When the heat treatment as in Patent Document 1 is performed, not only the resin volatilizes but also the resin decomposes. If excessive decomposition occurs here, calories are lost, and the usefulness as a fuel is reduced. On the other hand, if the heat treatment is insufficient, the carbon fibers are not embrittled and crushed, and the resin is not sufficiently modified, so that the unburned residue of the carbon fibers may increase. I am concerned. Under these circumstances, there is a demand for a technique capable of appropriately modifying CFRP (carbon fiber reinforced plastic). Moreover, since the amount of waste containing CFRP is expected to increase in the future, a technique for efficiently treating such waste is required.

Therefore, the present disclosure provides a fuel reforming method and a fuel reforming apparatus capable of smoothly reforming waste containing carbon fiber reinforced plastic into fuel.

The fuel reforming method according to one aspect of the present disclosure is heating to reform waste containing carbon fiber reinforced plastic by heating it in a temperature range of 250 to 450 ° C. in an atmosphere having an oxygen concentration of 13% by volume or less. Has a process.

In the above fuel reforming method, by setting the heating temperature and the oxygen concentration in the atmosphere within a specific range, the decomposition of the resin proceeds smoothly, and the waste is used as fuel in a shorter time than when heating in the atmosphere. It can be modified. Since such a fuel is excellent in combustibility and has a reduced volume, it is possible to reduce the unburned residue of carbon fibers. Further, since the combustion of the decomposed gas generated by the decomposition of the resin in the heating step is suppressed, the total amount of heat that can be used as the fuel (solid fuel and gaseous fuel) can be increased. In addition, "volume%" in this disclosure is a volume ratio in a standard state (0 ° C., 1 bar atm).

In the heating step, it is preferable to heat the waste in the above atmosphere in the above temperature range for 30 minutes to 4 hours. As a result, the modification of the resin in the heating step can be further optimized, and the amount of heat that can be used as fuel, for example, can be further increased. In addition, it is possible to suppress an increase in energy consumption required for reforming.

The fuel reforming method preferably includes a supply gas preparation step of obtaining a supply gas adjusted to a predetermined oxygen concentration by using at least one gas selected from water vapor, carbon dioxide, and nitrogen. In this case, it is preferable to adjust the oxygen concentration of the atmosphere in the heating step by using the above-mentioned supply gas.

When a continuous firing furnace or the like is used in the heating process, oxygen (atmosphere) may flow in from the waste inlet or the like. By using the supply gas adjusted to a predetermined oxygen concentration in the supply gas preparation step according to the oxygen inflow amount, the oxygen concentration in the atmosphere in the heating step can be stably maintained in a predetermined range. can. Further, if the gas used in these supply gas preparation steps is a gas generated in any of the fuel reforming methods, the energy efficiency of the entire fuel reforming method should be increased, and the fuel production efficiency should be enhanced. Can be done.

The above fuel reforming method preferably includes a decomposition gas combustion step of recovering and burning the decomposition gas generated in the heating step. In the above heating step, waste containing carbon fiber reinforced plastic is heated under conditions where the oxygen concentration is significantly lower than that of the atmosphere, thereby suppressing the combustion of gas generated by the thermal decomposition of the resin, and the gas having a high calorific value as the decomposition gas. Can be obtained. By such a decomposition gas combustion step of burning the decomposition gas, the calorific value of the decomposition gas can be effectively utilized. The combustion heat generated at this time may be used as a heat source for boiler power generation, drying of waste, and the like. This can improve the energy efficiency of the entire fuel reforming method.

It is preferable to use the combustion exhaust gas generated in the decomposition gas combustion step as a heat source in the heating step. By using the combustion exhaust gas generated in the decomposition gas combustion process as a heat source in the heating process in this way, the energy efficiency of the entire fuel reforming method can be improved.

The above fuel reforming method has a contact step of bringing the combustion exhaust gas generated in the decomposition gas combustion step into contact with water, and the cooling gas obtained in the contact step is used to adjust the oxygen concentration of the atmosphere in the heating step. It is preferable to do so. The combustion exhaust gas generated in the decomposition gas combustion process has a low oxygen concentration and a high carbon dioxide concentration. Then, by bringing such combustion exhaust gas into contact with water, a cooling gas containing water vapor can be obtained. Such a cooling gas is more suitable as a gas for adjusting the oxygen concentration in the heating step. Further, since it is not necessary to install a separate gas supply facility for adjusting the oxygen concentration in the atmosphere of the heating process, the process and the facility can be simplified.

The fuel reformer according to one aspect of the present disclosure heats and reforms waste containing carbon fiber reinforced plastic by heating it in a temperature range of 250 to 450 ° C. in an atmosphere having an oxygen concentration of 13% by volume or less. It has a part.

In the above fuel reformer, by setting the heating temperature and the oxygen concentration in the atmosphere within a specific range, the decomposition of the resin proceeds smoothly, and the fuel is reformed in a shorter time than when heating in the atmosphere. be able to. Since such a fuel is excellent in combustibility and has a reduced volume, it is possible to reduce the unburned residue of carbon fibers. Further, since the combustion generated by the decomposition of the resin is suppressed in the heating portion, the total amount of heat that can be used as the fuel (solid fuel and gaseous fuel) can be increased.

In the heating section, it is preferable to heat the waste in the above atmosphere in the above temperature range for 30 minutes to 4 hours. As a result, the modification of the resin can be further optimized, and the amount of heat that can be used as fuel, for example, can be further increased. In addition, it is possible to suppress an increase in energy consumption required for reforming.

The fuel reformer preferably includes a supply gas preparation unit that obtains a supply gas adjusted to a predetermined oxygen concentration by using at least one gas selected from steam, carbon dioxide, and nitrogen. In this case, it is preferable to adjust the oxygen concentration of the atmosphere in the heating portion by using the supply gas.

When, for example, a continuous firing furnace or the like is used as the heating part, oxygen (atmosphere) may flow in from the waste inlet or the like. By using the supply gas adjusted to a predetermined oxygen concentration in the supply gas preparation unit according to such an oxygen inflow amount, the oxygen concentration in the atmosphere in the heating unit can be stably maintained in a predetermined range. can. Further, if the gas used for these supply gas preparation units is a gas generated in any of the facilities in the fuel reformer, the energy efficiency of the entire fuel reformer is enhanced and the fuel production efficiency is enhanced. be able to.

The fuel reformer preferably has a decomposed gas combustion unit that recovers and burns the decomposed gas generated in the heating unit. In the heating section, the waste containing carbon fiber reinforced plastic is heated under conditions where the oxygen concentration is significantly lower than that of the atmosphere. Therefore, the combustion of the gas generated by the thermal decomposition of the resin is suppressed, and the amount of heat as the decomposition gas is suppressed. High gas can be obtained. By the decomposition gas combustion unit that burns such decomposition gas, the calorific value of the decomposition gas can be effectively utilized. The combustion heat generated at this time may be used as a heat source for boiler power generation, drying of waste, and the like. This can improve the energy efficiency of the entire fuel reformer.

It is preferable to supply the combustion exhaust gas generated in the decomposed gas combustion unit to the heating unit. By supplying the combustion exhaust gas generated in the decomposed gas combustion unit to the heating unit in this way, the combustion exhaust gas can be used as a heat source. This can improve the energy efficiency of the entire fuel reformer.

The fuel reformer has a contact portion for contacting water with the combustion exhaust gas generated in the decomposed gas combustion portion, and the cooling gas obtained at the contact portion is used to adjust the oxygen concentration of the atmosphere in the heating portion. It is preferable to do so. The combustion exhaust gas generated in the decomposed gas combustion section has a low oxygen concentration and a high carbon dioxide concentration. Then, by bringing such combustion exhaust gas into contact with water, a cooling gas containing water vapor can be obtained. Such a cooling gas is more suitable as a gas for adjusting the oxygen concentration in the heating unit. Further, since it is not necessary to install a separate gas supply facility for adjusting the oxygen concentration in the atmosphere of the heating unit, the device configuration can be simplified.

According to the present disclosure, it is possible to provide a fuel reforming method and a fuel reforming apparatus capable of smoothly reforming waste containing carbon fiber reinforced plastic into fuel.

It is a figure which shows one Embodiment of the fuel reformer. It is a figure which shows another embodiment of the fuel reformer. It is a figure which shows still another embodiment of the fuel reformer.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and duplicate description may be omitted in some cases. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratio of each element is not limited to the ratio shown in the figure.

The fuel reforming method according to one embodiment includes a supply gas preparation step of obtaining a supply gas adjusted to a predetermined oxygen concentration using at least one gas selected from water vapor, carbon dioxide, and nitrogen, and a carbon fiber. A heating step in which waste containing reinforced plastic is heated to a temperature range of 250 to 450 ° C. to obtain a modified product in an atmosphere having an oxygen concentration of 13% by volume or less, and a flammable gas generated in the heating step. It has a decomposition gas combustion step of burning the decomposition gas containing the above, and a contact step of bringing the combustion exhaust gas generated in the decomposition gas combustion step into contact with water.

The heating step heats the waste containing carbon fiber reinforced plastic. The anti-fusing agent may be heated with the waste. Examples of the anti-fusing agent include pulverized coal and the like. By using the anti-fusion agent, it is possible to prevent the melted plastics from fusing to each other and to prevent the melted plastics from adhering to the heating equipment.

Carbon fiber reinforced plastic (CFRP) contains carbon fiber and resin. Examples of the resin include thermosetting resins such as epoxy resins. Examples of the carbon fiber include those produced by carbonizing acrylic fiber or pitch as a raw material at a high temperature. However, the carbon fiber reinforced plastic may contain components other than those described above.

The waste may be derived from daily necessities, personal computers, home appliances, automobiles, aircraft, sports equipment, construction and civil engineering fields, and the like. These wastes may be shredder dust generated by the disposal of automobiles, home appliances, and the like. The waste may contain not only carbon fiber reinforced plastics but also resins such as carbon fiber-free plastics. The waste may contain foreign substances such as metal and rubber in addition to carbon fibers and resins.

In the heating step, it is preferable to heat the waste in an atmosphere having an oxygen concentration of 13% by volume or less in a temperature range of 250 to 450 ° C. for 30 minutes to 4 hours. By setting the temperature in such a range, the decomposition of the resin can be rapidly promoted while suppressing the energy consumption. From the same viewpoint, the temperature range may be 300 to 400 ° C. or 330 to 380 ° C.

The heating time in the above temperature range in the heating step may be 1 hour to 3.5 hours, or 1.5 hours to 3 hours. If the heating time is too short, the decomposition and volume reduction of the resin will be insufficient depending on the state of the waste containing CFRP, and the carbon fiber tends to remain unburned when the modified product is burned. On the other hand, if the heating time becomes too long, the decomposition of the resin proceeds sufficiently, but the energy efficiency of the fuel reforming method as a whole tends to decrease.

The oxygen concentration in the atmosphere in the heating step is 13% by volume or less, preferably 12% by volume or less, and more preferably 11% by volume or less. By lowering the oxygen concentration in the atmosphere in the heating step, the decomposition of the resin is promoted, and the reforming of the waste can be smoothly promoted. In addition, the risk of ignition of flammable gas generated by decomposition can be significantly reduced, and the safety of the process can be improved.

On the other hand, the lower limit of the oxygen concentration in the atmosphere in the heating step may be 1% by volume or 2% by volume. When the oxygen concentration is low, the decomposition of the resin becomes particularly fast, so that the reforming of the waste containing CFRP is completed in a short time. However, if the oxygen concentration is too low, it becomes difficult to adjust the progress of the decomposition of the resin. If the decomposition proceeds too much, the resin tends to be reduced too much, and carbon fibers tend to be isolated during the heating process, making it difficult to handle the modified product.

The oxygen concentration in the heating step may be adjusted by at least one of the oxygen concentration of the supply gas supplied in the heating step and the flow rate of the supply gas. After entering the normal operating state from the stopped state, the processing conditions can be stabilized by controlling the oxygen concentration of the supplied gas. The pressure in the heating step may be less than atmospheric pressure. By setting the pressure to less than atmospheric pressure, it is possible to prevent the decomposition gas from flowing out from the heating equipment. In addition, the vaporization of the tar component generated during decomposition is promoted, and the fusion of the modified product can be suppressed.

The oxygen concentration of the supply gas supplied to the heating step is adjusted in the supply gas preparation step. The oxygen concentration of the supply gas is preferably adjusted with reference to the oxygen concentration of the heating step in order to maintain the oxygen concentration of the atmosphere in the heating step within the target range. The oxygen concentration of the supply gas may be 12% by volume or less, 10% by volume or less, or 8% by volume or less.

In the heating step, a gas other than the supply gas obtained in the supply gas preparation step may be supplied. Such a gas may be a gas (air) whose oxygen concentration can be adjusted at all or little. In this case, the oxygen concentration in the heating step may be adjusted by the oxygen concentration of the feed gas obtained in the feed gas preparation step. In the supply gas preparation step, even if a supply gas having a predetermined oxygen concentration is obtained by using at least one gas selected from water vapor, carbon dioxide, and nitrogen and a gas (air) whose oxygen concentration cannot be adjusted at all or almost. good.

At least one gas selected from the group consisting of water vapor, carbon dioxide and nitrogen contained in the supply gas is preferably derived from any step in the reforming method of the present fuel. This eliminates the need to separately procure gas to adjust the oxygen concentration in the heating process, and can reform the waste at a lower cost. However, the supply of gas not derived from the above steps is not excluded, and the insufficient gas may be supplemented by using a steam generator or the like, if necessary.

The oxygen concentration in each gas may be measured by, for example, an oxygen concentration meter of a zirconia type or a magnetic force type, or may be analyzed in a separately provided oxygen concentration analysis step.

The modified product containing CFRP obtained in the heating step contains at least a partially decomposed resin and carbon fiber. In addition, it may contain a residue of a foreign substance such as metal and rubber that has not been completely separated from the original waste, and a substance derived from an auxiliary raw material that has been added to the treatment step at the same time.

In the heating process, the waste is heated in an atmosphere in which the oxygen concentration is significantly lower than that in the atmosphere. Therefore, the combustion of the decomposition gas generated by the decomposition of the resin is suppressed, and a high-calorie decomposition gas containing a high proportion of flammable components can be obtained. That is, not only the reformed product but also the decomposed gas can be converted into fuel. Since both the reformed product and the fuel gas can be used as fuel in this way, the total fuel recovery amount including the solid fuel and the gaseous fuel can be sufficiently increased.

Since the decomposition gas in the reforming method of the present embodiment contains a large amount of flammable components, it has a decomposition gas combustion step of recovering and burning the decomposition gas generated in the heating step. As a result, the decomposed gas can be effectively used as fuel. Further, for example, the combustion exhaust gas of this decomposed gas may be used as a heat source in the heating step. As a result, the heat of combustion of the decomposed gas can be effectively utilized.

In the contact process, the combustion exhaust gas generated in the decomposition gas combustion process is brought into contact with water. Thereby, a cooling gas containing carbon dioxide and water vapor can be easily obtained. Such a cooling gas may be used as it is in the heating step in order to adjust the oxygen concentration in the heating step, or may be mixed with another gas in the supply gas preparation step to be used as the supply gas. As a result, the combustion exhaust gas can be effectively used.

In the fuel reforming method according to another embodiment, after the heating step described above, a cooling step of cooling the reformed product containing CFRP obtained in the heating step with water and a crushing step of crushing the cooled reformed product. Then, a recovery step may be performed in which the crushed modified product is classified and a part of the modified product (coarse product) is recovered according to the size of the modified product. In the cooling step, water and the reformed product may be brought into direct contact with each other for cooling, or may be indirectly cooled via a cooling medium or the like. For example, the modified product may be introduced into an iron cylinder and sprinkled with water from the outside of the cylinder to cool it. By performing such cooling, smooth cooling is possible, and the time required for cooling can be shortened.

The size of the modified product after pulverization is not particularly limited, and may be, for example, 10 mm or less, 5 mm or less, or 3 mm or less. The crushing step may be performed using, for example, a vertical mill or a tube mill. By using a vertical mill, the pulverization step and the recovery step may be performed in parallel.

In the recovery step, the modified product crushed in the crushing step is classified, and a part of the modified product is recovered according to the size of the modified product. For example, if a material larger than a desired size remains, the coarse material may be classified and collected. The classification may be performed by a classification machine or by a vertical mill having both a crushing function and a classification function.

Of the modified products recovered in the recovery step, the coarse one may be crushed again in the crushing step. By having such a step, large-sized carbon fibers can be excluded from the modified product. The reformed product from which bulky substances have been removed in the recovery process can be burned as solid fuel. For example, it may be burned in a kiln or a calcining furnace of a cement manufacturing facility.

The reforming method having the above heating step can rapidly reform the waste containing CFRP. Since the modified product that has undergone the above heating step has a lower strength than that before the modification due to the progress of decomposition of the resin, it is easier to be crushed than before the modification. Therefore, the carbon fibers contained in the modified product can be easily refined. Further, since the volume of the resin is reduced by the modification, the time required for burning the resin is shortened, and the combustion of carbon fibers is smoothly started. As a result, the unburned residue of carbon fibers can be sufficiently reduced. Thereby, for example, it is possible to prevent the carbon fibers contained in the exhaust gas generated when the reformed product is used as the solid fuel from adversely affecting the electrostatic precipitator or the like for exhaust gas treatment.

The reforming method may be performed using, for example, the fuel reforming device 100 according to the embodiment shown in FIG. The reformer 100 of FIG. 1 includes a heating unit 20 for obtaining a reformed product by heating waste containing carbon fiber reinforced plastic in an atmosphere having an oxygen concentration of 13% by volume or less in a temperature range of 250 to 450 ° C. A cooling unit 30 for cooling the modified product with water, a crushing unit 40 for crushing the modified product cooled with water, and a crushed modified product are classified, and at least a part of the modified product is classified according to the size of the modified product (at least a part of the modified product ( It includes a recovery unit 50 that collects (coarse substances), a decomposition gas combustion unit 60 that uses the decomposition gas generated in the heating unit 20 as fuel, and a supply gas preparation unit 90 that prepares the supply gas to be supplied to the heating unit 20.

The decomposition gas containing a flammable component generated in the heating step of the heating unit 20 is recovered by the decomposition gas recovery unit 80 and burned by the decomposition gas combustion unit 60. In this way, the decomposition gas generated in the heating unit 20 can be effectively used as a heat source. After performing the heating step in the heating section 20, the cooling section 30 may perform the cooling step, the crushing section 40 may perform the crushing step, and the recovery section 50 may perform the recovery step, respectively. The heating unit 20 is preferably an external heating type heating device. As the heating unit 20, for example, an externally heated rotary kiln can be used. Further, the crushing unit 40 may be used as, for example, a vertical mill, and crushing and classification of the modified product may be performed in parallel. Therefore, the description of each step can be applied to each component of the reformer 100. The reformer 100 can reform the waste containing the carbon fiber reinforced plastic to obtain a reformed product having excellent combustibility.

The supply gas preparation unit 90 supplies the heating unit 20 with a supply gas containing at least one selected from the group consisting of water vapor, carbon dioxide, and nitrogen, and adjusts the atmosphere of the heating unit 20 to an oxygen concentration of 13% by volume or less. do. The supply gas preparation unit 90 preferably supplies a gas containing water vapor to the heating unit 20. As the steam, steam obtained by cooling the reformed product that has undergone the heating step in the cooling unit 30 may be used. As a result, the oxygen concentration of the heating unit 20 can be easily reduced while the reforming unit is quickly cooled after heating. The supply gas preparation unit 90 may have a control valve for adjusting the gas flow rate, a calculation unit for setting a target gas flow rate, and a transmission unit for exchanging signals between the calculation unit and the control valve.

FIG. 2 is a diagram showing a fuel reformer according to another embodiment. In addition to the configuration of the reformer 100 of FIG. 1, the reformer 101 of FIG. 2 includes a contact portion 62 that contacts the exhaust gas from the decomposition gas combustion unit 60 and water to obtain cooling gas. At the contact portion 62, cooling gas is obtained by performing a contact step of bringing water and exhaust gas into contact with each other. This cooling gas may contain water vapor.

A part or all of the cooling gas (water vapor-containing gas) obtained in the contact portion 62 is introduced into the cooling unit 30 and the heating unit 20 via the supply gas preparation unit 91. Excess cooling gas may be discharged to the outside of the system. The cooling gas may be introduced into the heating unit 20 via the cooling unit 30. The supply flow rate of the cooling gas obtained by the contact unit 62 to the heating unit 20 is adjusted by the supply gas preparation unit 91. In addition to the function of the supply gas preparation unit 90 of FIG. 1, the supply gas preparation unit 91 has a function of calculating the flow rate of the cooling gas supplied to the heating unit 20 and releasing excess exhaust gas to the atmosphere. May be good.

The supply gas preparation unit 91 may control the oxygen concentration in the heating unit 20 by adjusting the flow rate of the cooling gas cooled by the contact unit 62 to the heating unit 20. Further, the supply gas preparation unit 91 includes a cooling gas cooled by the contact unit 62 and another gas different from the cooling gas (for example, a gas containing at least one selected from the group consisting of water vapor, carbon dioxide, and nitrogen). The oxygen concentration of the supply gas supplied to the heating unit 20 may be controlled by adjusting the mixing ratio of the above. The supply gas preparation unit 91 is provided between the heating unit 20 and the cooling unit 30 to prepare a supply gas to be supplied to the heating unit 20 by mixing the water vapor-containing gas generated in the cooling unit 30 with another gas. May be good.

Other configurations of the reformer 101 of FIG. 2 are the same as those of the reformer 100 of FIG. 1, and the description of the reformer 100 can be applied.

FIG. 3 is a diagram showing a fuel reformer according to still another embodiment. The reformer 102 of FIG. 3 is different from the reformer 100 of FIG. 1 in that a part of the reformer (coarse product) recovered by the recovery unit 50 is recharged into the heating unit 20. As a result, the decomposition and volume reduction of the resin constituting the CFRP further progresses, and when it is introduced into the crushing section 40 again, it becomes easier to be crushed. This makes it possible to sufficiently reduce the unburned residue generated when the reformed product is burned.

In the reformer 102 of FIG. 3, the exhaust gas generated in the decomposed gas combustion unit 60 is supplied to the heating unit 20 by the combustion exhaust gas supply unit 74 (heat source introduction unit). In this way, the combustion exhaust gas may be used as the heat source of the heating unit 20. In this case, the supply gas preparation unit 90 adjusts the flow rate and oxygen concentration of the supply gas supplied by the heating unit 20 in consideration of the flow rate and oxygen concentration of the exhaust gas from the combustion exhaust gas supply unit 74. In this way, energy efficiency can be further improved.

Other configurations of the reformer 102 of FIG. 3 are the same as those of the reformer 100 of FIG. 1, and the description of the reformer 100 can be applied. The contents of the above-mentioned fuel reforming method can be applied to the reforming devices 100, 101, and 102 of FIGS. 1, 2, and 3.

The reforming devices 100, 101, 102 can rapidly reform the waste containing CFRP. The modified product that has passed through the heating unit 20 has a lower strength than that before the modification due to the progress of decomposition of the resin, so that the modified product is more likely to be crushed than before the modification. Therefore, the carbon fibers contained in the modified product can be easily refined. Further, since the volume of the resin is reduced by the modification, the time required for burning the resin is shortened, and the combustion of carbon fibers is smoothly started. As a result, the unburned residue of carbon fibers can be sufficiently reduced.

Although some embodiments have been described above, the present disclosure is not limited to the above embodiments. For example, the contents related to each embodiment of the fuel reforming method may be combined. Further, a crushing step of crushing the waste may be performed before the heating step. The crushing step may be performed by, for example, a crushing unit (not shown) provided on the upstream side of the heating unit 20 of any of the reforming devices 100, 101, and 102. In the crushing step, the waste may be crushed to a size of, for example, 10 to 100 mm. As the crushing part, a normal crusher can be used. By providing the crushing section, it is possible to prevent the waste from being clogged or blocked in the heating section 20, the cooling section 30, the crushing section 40 and the recovery section 50, and to reform the waste more smoothly. It becomes.

The contents of the present disclosure will be described in more detail below with reference to specific experimental examples. With the carbon fiber reinforced plastic itself contained in the waste, it is difficult to prepare a test piece having a uniform fiber content. If the fiber content fluctuates, there is a concern that it will be difficult to accurately determine the decomposition behavior. Therefore, here, the decomposition behavior of epoxy resin, which is a typical resin contained in carbon fiber reinforced plastic, was compared and examined.

(Experimental Example 1)
TG-DTA analysis (thermogravimetric-differential thermal analysis) of commercially available epoxy resins was performed in a plurality of different atmospheres. The analysis conditions were as follows.

<Analysis conditions>
Device name: TG-DTA 6300 (manufactured by SII Nanotechnology Co., Ltd.)
Sample mass: 2 mg
Temperature rise rate: 10 ° C / min Maximum temperature reached: 350 ° C
Retention time at maximum temperature: 3 hours Atmosphere: Adjust by diluting dry air with nitrogen gas (oxygen concentration is measured by an oxygen concentration meter at the introduction line to the analyzer)

The oxygen concentration in the atmosphere was 21% by volume (atmosphere), 14% by volume, 8% by volume, 3% by volume, and 0% by volume, for a total of 5 types. From the results of TG-DTA analysis in each atmosphere, it was confirmed that the lower the oxygen concentration, the more the weight loss is promoted. Table 1 shows the time required for the weight loss rate to reach 40%. In addition, Table 2 shows the weight loss rate from the start of temperature rise to the time when 60 minutes have passed.

As shown in Table 1, it was found that when the oxygen concentration decreased from 21% by volume (atmosphere) to 14% by volume, the arrival time was shortened by about 20%. Under the condition that the oxygen concentration was 8% by volume or less, the arrival time was less than half that of the atmosphere. It was confirmed that an atmosphere with a low oxygen concentration is effective in shortening the time required for decomposing the epoxy resin.

As shown in Table 2, at a relatively early stage after the start of temperature rise, the lower the oxygen concentration, the larger the weight loss rate. From this, it was confirmed that the oxygen concentration in the atmosphere affects the decomposition rate of the epoxy resin even at a relatively low temperature. The column of "vs atmosphere" in Table 2 shows the difference in the weight loss rate from the start of temperature rise to the time when 60 minutes have passed from the atmosphere (oxygen concentration: 21% by volume). It was confirmed that when the oxygen concentration reached 0% by volume, the decomposition of the epoxy resin was significantly promoted.

(Experimental Example 2)
Among the samples obtained by heating in Experimental Example 1, the calorific value analysis of the samples heated in an atmosphere of oxygen concentration of 14% by volume, 8% by volume, 3% by volume and 0% by volume was performed. The analysis was performed in accordance with JIS M 8814 using a cylinder type calorimeter (model: 1013-J) manufactured by Yoshida Seisakusho Co., Ltd. The analysis results are shown in Table 3.

Table 3 shows the result of the calorific value, the product of the residual amount (100-weight reduction rate) remaining after heating, and the calorific value. The larger the value of residual amount × calorific value, the larger the amount of heat of the fuel recovered as solid content when the same amount of waste is processed. From the results in Table 3, it was confirmed that the lower the oxygen concentration (excluding the case where the oxygen concentration is 0% by volume), the larger the calorific value, and the larger the value of the residual amount × the calorific value. From this, it was confirmed that by performing the heating step of heating the CFRP under predetermined conditions, a modified product having excellent flammability and a reduced volume of resin can be smoothly obtained. It is considered that when such a modified product is burned, carbon fibers can be smoothly and completely burned while utilizing the energy generated by the combustion. When the oxygen concentration was 0% by volume, the weight loss rate was large, so the value of residual x calorific value was smaller than in other atmospheres, but the weight loss of the resin was the largest and the heat generated by the modified product after heating. The amount was larger than when the oxygen concentration was 14% by volume. Therefore, it is considered that the combustion of carbon fibers can be promoted when the oxygen concentration is 0% by volume as compared with the case where the oxygen concentration is 14% by volume.

(Experimental Example 3)
TG-DTA analysis (thermogravimetric-differential thermal analysis) and DSC analysis (differential scanning calorimetry) were performed using the same epoxy resin used in Experimental Example 1 in a plurality of different atmospheres.
The analysis conditions for each were as follows.

<Analysis conditions for TG-DTA>
Device name: TG-DTA 6300 (manufactured by SII Nanotechnology Co., Ltd.)
Sample mass: 2 mg
Temperature rise rate: 10 ° C / min Maximum temperature reached: 800 ° C
Retention time at maximum temperature: None Atmosphere: Adjusted by diluting dry air with nitrogen gas (oxygen concentration is measured by an oxygen concentration meter at the introduction line to the analyzer)

<DSC analysis conditions>
Device name: DSC6200 (manufactured by SII Nanotechnology Co., Ltd.)
Sample mass: 2.5 mg
Temperature rise rate: 10 ° C / min at 20-200 ° C, 2.5 ° C / min at 200-600 ° C
Atmosphere: Same as TG-DTA analysis conditions

The oxygen concentration in the atmosphere was 21% by volume (atmosphere), 8% by volume, and 3% by volume, for a total of three types. From the TG-DTA analysis result and the DSC analysis result in each atmosphere, the weight reduction rate and the calorific value up to the time when the temperature was raised to 600 ° C. were determined. Table 4 shows these results.

According to the results shown in Table 4, there was no significant difference in the weight loss rate among the three types of oxygen concentrations of 21% by volume, 8% by volume, and 3% by volume. This is considered to be due to the fact that it is not held in the low temperature range and the high temperature of 600 ° C. On the other hand, the calorific value varies greatly depending on the oxygen concentration. This indicates that the mechanism of weight loss is different. That is, while the weight loss is mainly caused by combustion under the condition of high oxygen concentration, the rate of weight loss due to the breakage, decomposition, and volatilization of chemical bonds increases as the oxygen concentration is low. It is thought that there is.

From these results, it is considered that the composition of the decomposition gas obtained by heating the carbon fiber reinforced plastic greatly differs depending on the atmosphere (oxygen concentration) at the time of heating. That is, it is considered that the decomposition gas obtained by heating the carbon fiber reinforced plastic in a low oxygen atmosphere has a higher calorie than the gas obtained by heating in a high oxygen atmosphere. From the results shown in Table 4, the final weight loss rate of the epoxy resin does not change significantly. Therefore, if the carbon fiber reinforced plastic is heated in a low oxygen atmosphere and the decomposition gas obtained at that time is used as fuel, it will be improved. It is considered that the total fuel recovery amount of quality solid fuel and gaseous fuel (decomposed gas) can be sufficiently increased.

According to the present disclosure, it is possible to provide a fuel reforming method and a fuel reforming apparatus capable of smoothly reforming waste containing carbon fiber reinforced plastic.

20 ... heating part, 30 ... cooling part, 40 ... crushing part, 50 ... recovery part, 60 ... decomposed gas combustion part, 62 ... contact part, 74 ... combustion exhaust gas supply part, 80 ... decomposition gas recovery part, 90 ... supply gas Preparation unit, 91 ... Supply gas preparation unit, 100, 101, 102 ... Reformer.

Claims (12)

A fuel reforming method comprising a heating step of heating waste containing carbon fiber reinforced plastic to a temperature range of 250 to 450 ° C. in an atmosphere having an oxygen concentration of 13% by volume or less. The method for reforming a fuel according to claim 1, wherein in the heating step, the waste is heated in the atmosphere in the temperature range for 30 minutes to 4 hours. It has a supply gas preparation step of obtaining a supply gas adjusted to a predetermined oxygen concentration using at least one gas selected from water vapor, carbon dioxide, and nitrogen.
The method for reforming a fuel according to claim 1 or 2, wherein the supply gas is used to adjust the oxygen concentration in the atmosphere in the heating step. The method for reforming a fuel according to any one of claims 1 to 3, further comprising a decomposition gas combustion step of recovering and burning the decomposition gas generated in the heating step. The method for reforming fuel according to claim 4, wherein the combustion exhaust gas generated in the decomposition gas combustion step is used as a heat source in the heating step. It has a contact process that brings the combustion exhaust gas generated in the decomposition gas combustion process into contact with water.
The method for reforming a fuel according to claim 4 or 5, wherein the cooling gas obtained in the contact step is used to adjust the oxygen concentration in the atmosphere in the heating step. A fuel reforming device including a heating unit for reforming waste containing carbon fiber reinforced plastic by heating it in a temperature range of 250 to 450 ° C. in an atmosphere having an oxygen concentration of 13% by volume or less. The fuel reformer according to claim 7, wherein the heating unit heats the waste in the atmosphere in the temperature range for 30 minutes to 4 hours. It is equipped with a supply gas preparation unit that obtains a supply gas adjusted to a predetermined oxygen concentration using at least one gas selected from water vapor, carbon dioxide, and nitrogen.
The fuel reformer according to claim 7 or 8, wherein the supply gas is used to adjust the oxygen concentration of the atmosphere in the heating unit. The fuel reforming apparatus according to any one of claims 7 to 9, further comprising a decomposition gas combustion unit that recovers and burns the decomposition gas generated in the heating unit. The fuel reformer according to claim 10, wherein the combustion exhaust gas generated in the decomposed gas combustion unit is supplied to the heating unit. It has a contact part that brings the combustion exhaust gas generated in the decomposed gas combustion part into contact with water.
The fuel reforming apparatus according to claim 10 or 11, wherein the cooling gas obtained at the contact portion is used to adjust the oxygen concentration of the atmosphere in the heating portion.

Images