Method for producing organic waste fuel

Abstract

To provide a method for further safely producing an organic waste fuel even when waste fermentation compost is used as an object raw material.SOLUTION: In the method for producing an organic waste fuel according to the present invention, a mixture is obtained by performing a mixing treatment for mixing a target raw material composed of organic wastes other than waste oil with oils and fats, heating the mixture under an environment with limited oxygen, and determining whether or not a primary heating treatment for heating the target raw material to reduce the water content to a predetermined value is necessary when carbonizing a part of the organic compound constituting the mixture to thermally decompose is performed (step S1), and if it is determined that the primary heating treatment is unnecessary, the bulk density of the target raw material is measured (step S2), and it is determined whether or not the value of the obtained bulk density is equal to or less than a preset threshold value (step S3), and if it is not equal to or less than the threshold value, the mixing treatment and carbonizing treatment are performed (steps S43 and S44).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing organic waste fuel using waste generated in food service establishments such as retail stores and restaurants, or organic waste generated in the manufacturing process of food and beverages such as alcohol and food. [Background technology]

[0002] Retail stores, restaurants, and other food service establishments generate a large amount of organic waste every day, including expired rice balls, bento boxes, or bread, scraps of ingredients used in cooking, leftover food, and used oil. Food and beverage manufacturers also generate a large amount of organic waste. For example, shochu lees and sake lees at sake breweries, fruit lees at juice factories, and soy pulp and used oil at tofu factories. Similarly, ordinary households also generate organic waste, such as food waste and used oil.

[0003] In many cases, such organic waste is incinerated, but most of the energy generated by the incineration process is not recovered, resulting in a significant energy loss.

[0004] Therefore, the inventors developed a method for producing organic waste fuel by heating a target raw material composed of organic waste other than waste oil to obtain a primary heat-treated product in which the moisture content is reduced to approximately 5% by mass or more and approximately 30% by mass or less, mixing the resulting primary heat-treated product with 4% by mass or more and 30% by mass or less of fats and oils to obtain a mixture, and heating the resulting mixture at an appropriate temperature of 150°C or more and 250°C or less to perform a carbonization process in which some of the organic compounds that make up the mixture are pyrolyzed (Patent Document 1).This makes it possible to produce an organic waste fuel that can be easily handled as an intermediate product and final product, has improved storage safety, and is fully usable as fuel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-158750 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the inventors have conducted extensive research into various target raw materials and have found that the surplus fermented compost obtained by fermenting organic waste is discarded. When this discarded fermented compost is used as the target raw material, white smoke is emitted when the compost comes into contact with the outside air after the carbonization treatment described above is completed.

[0007] The present invention has been made in view of the above circumstances, and provides a method for producing organic waste fuel more safely, even when waste fermented compost is used as the target raw material. [Means for solving the problem]

[0008] (1) The method for producing organic waste fuel according to the present invention involves a mixing process in which a target raw material composed of organic waste other than waste oil is mixed with fats and oils to obtain a mixture, and then heating the mixture in an oxygen-limited environment to perform a carbonization process in which a portion of the organic compounds constituting the mixture are pyrolyzed, thereby producing organic waste fuel. , based on the moisture content of the target raw material, A determination is made as to whether or not a primary heat treatment is necessary to heat the target raw material and reduce the moisture content to a predetermined value. If it is determined that the primary heat treatment is unnecessary, the bulk density of the target raw material is measured, and if the obtained bulk density value is not equal to or less than a predetermined threshold value, In addition, if it is determined that primary heating is necessary, the above-mentioned The method is characterized by carrying out a mixing treatment and a carbonization treatment.

[0009] In the method for producing organic waste fuel of the present invention, a mixture is obtained by carrying out a mixing process in which a target raw material composed of organic waste other than waste oil is mixed with fats and oils, and the mixture obtained is heated in an oxygen-limited environment and subjected to a carbonization process in which some of the organic compounds that make up the mixture are thermally decomposed, thereby producing organic waste fuel.

[0010] In this case, the target raw materials , based on the moisture content of the target raw material, The inventors conducted extensive research to determine whether a primary heating process, in which the target material is heated to reduce the moisture content to a predetermined value, is necessary, and found that for target materials for which primary heating process is not necessary, white smoke may be generated when the material is exposed to outside air after carbonization. As a result of extensive research, the inventors found that the state of the organic waste fuel obtained by carbonization of such target materials differs depending on the bulk density of the material, and thus completed the present invention.

[0011] That is, for the target raw material that is determined not to require primary heat treatment, the bulk density is measured, and it is determined whether the obtained bulk density value is equal to or less than a preset threshold value. If the bulk density value is not equal to or less than the threshold value, that is, if the bulk density value exceeds the threshold value, In addition, if it is determined that primary heat treatment is necessary, the oil and fat The mixture and carbonization are then carried out.

[0012] When the target raw material has a bulk density value below the threshold, it is very light and becomes fluffy when exposed to wind, which can cause the carbonization process to proceed excessively, resulting in the emission of smoke when exposed to the open air after the carbonization process is complete. In contrast, when the target raw material has a bulk density value above the threshold, it has an appropriate weight, so the carbonization process proceeds appropriately, and no signs of danger, such as the emission of smoke, are observed even when the carbonization process is complete and the raw material is exposed to the open air. Therefore, even when waste fermented compost is used as the target raw material, organic waste fuel can be safely produced.

[0013] on the other hand In the method for producing organic waste fuel according to the present invention, when the measured bulk density value is equal to or less than the threshold value, the mixing treatment and carbonization treatment are carried out, and it is determined whether the carbonization treatment has been completed. For example, based on the exhaust temperature of the carbonization process death , carbonization treatment is continued until it is judged to be completed, and then If it is determined that the organic waste fuel has been burned, a non-combustible gas is introduced into the obtained organic waste fuel, and the organic waste fuel is cooled in an atmosphere of the introduced non-combustible gas.

[0014] In the method for producing organic waste fuel of the present invention, when the bulk density of the target material determined not to require primary heating is below a threshold value, the mixing treatment and carbonization treatment described above are carried out in this order. For example, based on the exhaust temperature of the carbonization process Once it is determined that the process is complete, a non-flammable gas such as nitrogen gas or carbon dioxide gas is introduced into the resulting organic waste fuel, and the organic waste fuel is cooled in the introduced non-flammable gas atmosphere. After cooling, the organic waste fuel poses no risk even when exposed to outside air. This allows organic waste fuel to be produced safely, even when using waste fermented compost.

[0015] ( 2 On the other hand, in the method for producing organic waste fuel according to the present invention, a primary heat-treated product obtained by carrying out the primary heat treatment and / or a target raw material that has been determined not to require primary heat treatment and whose bulk density exceeds the threshold is obtained in advance, and it is determined that primary heat treatment is not required, and when the bulk density value obtained by measuring the target raw material is equal to or less than the threshold, The aforementioned Primary heat treatment product and / or The raw material is the target raw material, The method is characterized in that the additive is added until the measured bulk density value exceeds the threshold value.

[0016] In the method for producing organic waste fuel of the present invention, a primary heat-treated product obtained by carrying out the above-mentioned primary heat treatment and / or a target raw material that has been determined not to require primary heat treatment and whose bulk density exceeds the threshold value is obtained in advance.

[0017] On the other hand, if it is determined that primary heat treatment is unnecessary and the bulk density value obtained by measuring the target raw material is equal to or less than the threshold value, The aforementioned Primary heat treatment product and / or Add an appropriate amount of the raw material to the target raw material. After adding and thoroughly mixing them, the bulk density is measured, and the measured bulk density value is increased until it exceeds a threshold value. The aforementioned Primary heat treatment product and / or The aforementioned raw material Addition of the above to the applicable raw materials Repeat the mixing and bulk density measurement. Then, the mixing and carbonization processes are carried out in the same manner as before, and when it is determined that the carbonization process has been completed, an organic waste fuel is obtained without introducing a non-combustible gas into the obtained organic waste fuel.

[0018] This causes the bulk density value to exceed a threshold value, so even if the material is subsequently mixed with oils and fats and carbonized, organic waste fuel can be safely produced without the need for cooling under a non-flammable gas atmosphere.

[0019] ( 3 ) Furthermore, in the method for producing organic waste fuel according to the present invention, the threshold value is at least 0.50 g / ml.

[0020] As a result of intensive research by the present inventors, the threshold value was found to be at least 0.50 g / ml. Therefore, based on whether the bulk density of the target raw material for which primary heat treatment is judged unnecessary is 0.50 g / ml or less, the above-mentioned (1) or ( 2 By carrying out the operation of ), organic waste fuel can be safely produced. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a flowchart showing a procedure for producing organic waste fuel according to the present invention. [Figure 2] 1 is a flowchart showing a procedure for producing organic waste fuel according to the present invention. [Figure 3] 1 is a partially omitted front view of a vacuum heater used in an embodiment of the present invention. [Figure 4] 1 is a side view of a vacuum heater used in the practice of the present invention, with a portion thereof omitted. [Figure 5] 4 is a view of the vacuum heater shown in FIG. 3 taken along arrows VV. [Figure 6] 3 is a flowchart showing a procedure for producing organic waste fuel according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] (First Mode for Carrying Out the Invention) 1 and 2 are flow charts showing the procedure for producing organic waste fuel according to the present invention.

[0023] To produce the organic waste fuel according to the present invention, as shown in FIG. 1, it is determined whether or not to carry out primary heat treatment on organic waste (target raw material) other than waste oil (step S1).

[0024] Here, whether or not to perform primary heat treatment is determined based on the moisture content of the target raw material used to produce organic waste fuel. That is, if the moisture content of the target raw material is approximately 30% by mass or less, primary heat treatment is not performed, and if the moisture content of the target raw material is more than approximately 30% by mass, primary heat treatment is performed. In the present invention, approximately 30% by mass means approximately 30% by mass ±5% by mass.

[0025] For example, in the case of waste fermented compost, the moisture content is around 16% by mass, so primary heating is not performed. Similarly, primary heating is not performed when the target material is dried plant matter such as dried cut weeds, rice or wheat straw, or fallen leaves.

[0026] The moisture content of the target material can be measured using a heater or the like, but whether or not primary heating treatment should be performed can also be determined by a simple test. For example, if a handful of the target material is grasped, the target material is squeezed firmly in the palm of the hand, and pressure is applied. When the palm is opened, if the target material is formed into a ball-like shape, it is determined that primary heating treatment should be performed. On the other hand, if the target material is not formed into a ball-like shape when the palm is opened, but is in pieces, it is determined that primary heating treatment should not be performed.

[0027] In the present invention, a target raw material that has been subjected to a primary heating treatment to have a predetermined moisture content, or a target raw material that has a predetermined moisture content without being subjected to a primary heating treatment, is mixed with fats and oils to obtain a mixture, as described below, and the obtained mixture is subjected to a carbonization treatment to thermally decompose some of the organic compounds that make up the mixture. However, in the case of a target raw material that does not require the above-mentioned primary heating treatment, there is a risk of white smoke being generated after the carbonization treatment, so the bulk density of the target raw material is measured (step S2).

[0028] Here, the bulk density can be measured, for example, as follows. That is, a measuring container such as a graduated cylinder or measuring cup is used, and the target material is filled up to the position of the 100 ml measuring line, for example. At this time, the measuring container is vibrated by lightly tapping it. Next, if a measuring cylinder is used as the measuring container, the volume of the target material after the vibration is measured. On the other hand, if a measuring cup is used as the measuring container, the operation of filling the target material so that it reaches the position of the measuring line is repeated. Then, the mass of the target material including the measuring container is measured, and the mass of the target material is obtained by subtracting the mass of the measuring container, which was measured beforehand, and the obtained mass of the target material is divided by the volume of the target material to determine the bulk density.

[0029] When waste fermented compost was used as the target raw material, white smoke was sometimes generated after the carbonization process was completed. As a result of extensive investigation, the inventors of the present invention discovered that this phenomenon was caused by the bulk density of the target raw material.

[0030] That is, if the bulk density of the target raw material exceeds the threshold value, there is no risk of white smoke being generated after the carbonization process, whereas if the bulk density of the target raw material is equal to or less than the threshold value, there is a risk of white smoke being generated after the carbonization process. Here, the inventors' investigations revealed that the threshold value for the bulk density of the target raw material is approximately 0.47 g / ml.

[0031] Therefore, it is determined whether the bulk density value of the target raw material obtained in step S2 is equal to or less than a threshold value (step S3), and if the bulk density value exceeds the threshold value, the post-processing to be performed after the carbonization process is completed is not carried out, whereas if the bulk density value of the target raw material is equal to or less than the threshold value, the post-processing to be described later is carried out after the carbonization process is completed (steps S35, S36).

[0032] Meanwhile, the target raw materials determined to undergo primary heating treatment in step S1 are not particularly limited as long as they are organic waste other than dried organic waste such as waste oil, fermented compost waste, or dried plant matter. Examples include expired rice balls, bento boxes, or bread from food stores such as retailers and restaurants, scraps or leftover food from cooking ingredients, shochu lees or sake lees from sake breweries, fruit pomace from juice factories, soy pulp from tofu factories, and food waste from ordinary households, or mixtures of these. Sludge from sewage works can also be used as a target raw material. Note that the target raw materials may be subjected to a dehydration process beforehand depending on their moisture content.

[0033] If it is determined in step S1 that the primary heat treatment is necessary, the primary heat treatment is carried out on the target raw material as follows (step S41).

[0034] The primary heat treatment of the target raw material aims to reduce the moisture content of the target raw material to approximately 5% to approximately 30% by mass, preferably approximately 10% to approximately 15% by mass. If the moisture content of the primary heat treatment product is less than approximately 5% by mass, the primary heat treatment takes a long time, resulting in low processing efficiency and high running costs. Furthermore, if the moisture content of the primary heat treatment product exceeds approximately 30% by mass, there is a risk of excessive loss of the oils and fats mixed into the primary heat treatment product as the moisture remaining in the primary heat treatment product evaporates during the carbonization treatment process described below.

[0035] On the other hand, when the moisture content in the primary heat treatment is about 10% by mass to about 15% by mass, the treatment can be completed in a relatively short time, and there is almost no loss of the added oil or fat even in the carbonization treatment step.Furthermore, the storage stability is also high.

[0036] The method for heating and drying the target material is not particularly limited, and for example, the target material can be heat-treated by introducing heat directly or indirectly into the target material while stirring the target material.

[0037] In this case, it is preferable to carry out the primary heat treatment under a reduced pressure environment, as this shortens the treatment time. For example, when using a vacuum heater GV-35 (manufactured by Gaia Co., Ltd.), a primary heat-treated product in which the moisture content of the cabbage residue is reduced to approximately 10% by mass can be obtained in 8 hours under conditions of a pressure of -0.08 MPa to -0.09 MPa and a temperature of 190°C to 200°C. Furthermore, when using this vacuum heater, the end point of the primary heat treatment can be determined when the exhaust temperature reaches approximately 48°C.

[0038] The heating temperature in the primary heat treatment can be appropriately set to, for example, 50°C to 250°C.

[0039] Next, fats and oils are added to the thus obtained primary heat-treated product or to the target raw material whose bulk density exceeds the threshold value in step S3 (step S42), and the added fats and oils and the primary heat-treated product are mixed so that they are approximately uniform (step S43). Note that the mixing operation of the primary heat-treated product or the target raw material whose bulk density exceeds the threshold value with the fats and oils may be performed in the heater used for the primary heat treatment, or may be performed in a dedicated mixer different from the heater.

[0040] The type of oil or fat to be added is not particularly limited, and various animal and vegetable oils and fats can be used. They may be either solid or liquid at room temperature, but liquid oils at room temperature are preferred because they facilitate the mixing process described below. Furthermore, using waste oil and / or waste oil sludge generated in restaurants and food factories is preferred from the perspective of waste recycling.

[0041] On the other hand, the amount of fat or oil added is 4% by mass or more and 30% by mass or less, preferably 4% by mass or more and 12% by mass or less, of the primary heat-treated product or the target raw material whose bulk density exceeds the threshold value.

[0042] This is the case when a target raw material is used for which the fat content does not need to be taken into consideration, but there are cases where the target raw material is mixed with a material containing a relatively large amount of fat. When using such a target raw material, fats are added so that the primary heat-treated product or the target raw material whose bulk density has been measured has an fat content of 4% by mass to 30% by mass, preferably 4% by mass to 12% by mass.

[0043] When fats and oils are added and mixed into the primary heat-treated product or the target raw material whose bulk density exceeds the threshold so that the fat and oil content is 4% by mass or more, the ignition point of the organic waste fuel obtained by the carbonization process described above is higher than the ignition point of the organic waste fuel obtained by the carbonization process without adding fats and oils, thereby improving storage safety.

[0044] On the other hand, if fats and oils are added and mixed into the primary heat-treated product or the target raw material whose bulk density exceeds the threshold so that the fat and oil content exceeds 30 mass%, the organic waste fuel obtained by carbonization treatment will become sticky due to the added fats and oils, significantly reducing its handleability.

[0045] On the other hand, if fats and oils are added and mixed into the primary heat-treated product or the target raw material whose bulk density exceeds the threshold so that the fat and oil content is 12 mass% or more, even if the organic waste fuel obtained by carbonization is molded into pellets using a molding machine, pellets can be obtained without the added fats and oils seeping out.

[0046] Furthermore, when fats and oils are added and mixed into the primary heat-treated product or the target raw material whose bulk density exceeds the threshold so that the fat and oil content is 4% by mass or more, the calorific value per unit mass of the organic waste fuel obtained by carbonization exceeds the calorific value per unit mass of domestic general coal, which is 22,500 kJ / kg, and the calorific value per unit mass of imported general coal, which is 26,600 kJ / kg, and can be used as an alternative fuel to coal.

[0047] On the other hand, even if the amount of fats and oils added is 2% by mass of the primary heat-treated product or the target raw material whose bulk density exceeds the threshold, if the fat and oil content of the primary heat-treated product is 2% by mass or more, it will have a calorific value similar to the calorific value per unit mass of domestic general coal and can be used sufficiently as fuel.

[0048] The amount of fat or oil to be added to the primary heat-treated product or the target raw material whose bulk density exceeds the threshold value may be determined based on the amount of fat or oil contained in the primary heat-treated product obtained in the above-mentioned step S41 or the target raw material whose bulk density exceeds the threshold value. To measure the amount of fat or oil contained in the primary heat-treated product or the target raw material whose bulk density has been measured, for example, a normal hexane extractable substance analysis method using normal hexane as a solvent can be applied.

[0049] In addition, cabbage, baby corn, burdock, green beans, snow peas, salad greens, sunny lettuce, ginger leaves, broad beans, bamboo shoots, taros, purple jasmine, garlic stalks, red bell peppers, green peppers, asparagus, okra, turnips, pumpkins, cauliflower, cucumbers, mizuna, watercress, komatsuna, shiso, zucchini, snap peas, celery, daikon radish (root), daikon radish (leaf), onions, bok choy, gourds, tomatoes, long onions, eggplants, bitter melon, carrots, Chinese cabbage, myoga, sprout cabbage, Lily root, lettuce, red cabbage, lotus root, burdock, butterbur, bean sprouts, scallions, persimmons, chestnuts, cherries, bananas, papayas, strawberries, figs, kiwi fruit, watermelon, pears, pineapples, loquats, grapes, blueberries, mangoes, melons, peaches, apples, and the like contain almost no fats or oils themselves, so it is possible to add 4% by mass or more and 30% by mass or less, preferably 4% by mass or more and 12% by mass or less, of fats or oils to the primarily heat-treated product without checking the fats and oils contained in the primarily heat-treated product.

[0050] In step S43, the added oil and fat are mixed with the primary heat-treated product or the target raw material whose bulk density exceeds the threshold value to obtain a mixture, and the mixture is then carbonized (step S44).When the carbonization process is complete, the mixture is removed from the heater to obtain organic waste fuel (step S45).

[0051] Such carbonization treatment refers to the thermal decomposition of at least a portion of the organic compounds constituting the mixture by heating the mixture in an oxygen-limited environment, thereby enriching the amount of carbon per unit mass of the mixture.

[0052] In this embodiment, an oxygen-restricted environment is created by suctioning gas from a heater that heats the mixture and reducing the pressure inside the heater, thereby maintaining the oxygen-restricted environment and removing gases and the like that are generated by the thermal decomposition of organic compounds during the carbonization process.

[0053] The temperature at which the carbonization treatment is carried out should be above 100°C and at which the organic compounds constituting the mixture are thermally decomposed, but a temperature range of 150°C to 250°C, and more preferably 200°C or less, is preferred. If the carbonization treatment temperature is below 100°C, the carbonization treatment will take a long time, resulting in significantly low treatment efficiency and being impractical. Furthermore, odors caused by the waste will remain, hindering storage and distribution. Furthermore, if the carbonization treatment temperature exceeds 300°C, there is a risk of dioxin generation.

[0054] On the other hand, when carbonization is carried out in the temperature range of 150°C to 250°C, not only can the carbonization equipment be simplified and made smaller, but the carbonization can be completed in a relatively short time, reducing running costs as much as possible.Furthermore, when carbonization is carried out in the temperature range of 150°C to 200°C, in addition to these effects, the amount of tar and organic gas components generated during the carbonization process can be reduced, resulting in an increased yield of organic waste fuel.

[0055] The end of the carbonization process can be determined by the exhaust temperature of the vacuum heater used in the carbonization process. For example, the carbonization process is ended when the exhaust temperature at the vacuum suction port of the vacuum heater reaches about 40°C.

[0056] Meanwhile, for the target raw material whose bulk density is equal to or less than the threshold value in step S3, the same operations as those in steps S42 to S44 described above are carried out, such as adding fats and oils (step S31), mixing the fats and oils with the target raw material whose bulk density is equal to or less than the threshold value (step S32), and carbonization (step S33). The carbonization is carried out until it is determined that it is time to end the carbonization (step S34), and when it is determined that it is time to end the carbonization, post-processing is carried out.

[0057] Specifically, the post-processing involves filling the vacuum heater with a non-flammable gas such as nitrogen gas or carbon dioxide gas (step S35), stopping the operation of the vacuum heater, and gradually lowering the temperature inside the vacuum heater (step S36). After waiting until the temperature inside the vacuum heater drops below about 150°C (step S37), the process moves to step S45, where the waste is removed from the vacuum heater to obtain organic waste fuel.

[0058] As an apparatus capable of performing carbonization treatment under reduced pressure in a temperature range of 150°C to 250°C, for example, the following vacuum heater can be used. Note that this apparatus has a built-in agitator, so the above-mentioned primary heating treatment, mixing of the primary heating treatment material with fats and oils, and carbonization treatment can be performed in one unit.

[0059] Figures 3 and 4 are a partially omitted front view and a partially omitted side view of a vacuum heater used in the practice of the present invention, and Figure 5 is a view taken along the arrows VV of the vacuum heater shown in Figure 3. Note that the same numbers are used to designate corresponding parts in each figure. Also, in each figure, piping has been omitted as appropriate.

[0060] The heater 1, which heats the object to be heated, is a horizontally elongated rectangular parallelepiped, and the area below the center position in the height direction has a double bottom structure formed by an inner bottom and an outer bottom. A fluid heat medium is sealed between the inner bottom and the outer bottom, and is heated to the required temperature by a heater such as a plug heater 15, 15. The inner bottom is shaped like a U when viewed from the side, ensuring as large a contact area as possible with the object to be heated placed in the heater 1.

[0061] A penetrating shaft 11 is rotatably provided at a position slightly above the inner bottom of the heater 1 in a manner that penetrates both end faces of the heater 1, and the rotation of a stirring blade (not shown) supported by the penetrating shaft 11 stirs the material to be heated in the heater 1 so that it slides against the inner surface of the inner bottom of the heater 1. A driven pulley 12 is fitted and fixed to one end of the penetrating shaft 11, and the rotational force from the driving pulley 8 is transmitted to the driven pulley 12 by the driving pulley 8, an endless track such as a circular chain wound between them, and the stirring motor 7 that rotates the driving pulley 8, so that the penetrating shaft 11 is rotated.

[0062] In the heater 1 having such a structure, the temperature of the heat medium can be accurately adjusted by the plug heaters 15, 15, so the primary heating process and carbonization process described above can be carried out at predetermined temperatures. In addition, because heat is conducted to the inner bottom via the fluid heat medium, heat can be transmitted evenly throughout the inner bottom, and further, because the heated object dropped into the inner bottom is stirred, the entire heated object can be uniformly heated.

[0063] An inlet for inserting the object to be heated is provided in the ceiling of the heater 1, and this inlet can be closed airtightly by an inlet lid 13. On the other hand, an outlet for removing the object to be heated inside the heater 1 is provided in an appropriate position on the side of the heater 1, and this outlet can be closed airtightly by an outlet lid 14.

[0064] The aforementioned through shaft 11 has a hollow structure and is configured to be able to draw air from inside the heater 1, and one end of the through shaft 11 is connected to one end of an intake pipe 2 that communicates with a vacuum pump 5. In addition, a cylinder 3 filled with a non-flammable gas such as nitrogen gas or carbon dioxide gas is disposed near the other end of the through shaft 11, and the non-flammable gas in the cylinder 3 is introduced into the heater 1 through an introduction pipe disposed inside the through shaft 11, so that the inside of the heater 1 can be replaced with a non-flammable gas atmosphere.

[0065] The other end of the intake pipe 2 is connected to a spiral cooling pipe (not shown) disposed in the cooling tank 4, and the exhaust gas discharged from the heater 1 to the intake pipe 2 is cooled in the cooling tank 4 and separated into gas and liquid. The cooling tank 4 is also provided with a cooling device 42 incorporating a circulating pump 41 for circulating cooling water in the cooling tank 4, a cooling fan, etc.

[0066] A cyclone 6 is installed near the cooling tank 4, and the exhaust gas separated into gas and liquid in the cooling tank 4 is introduced into the cyclone 6 where dust is collected, and then sucked into the vacuum pump 5 and discharged from the vacuum pump 5 to the outside.

[0067] Incidentally, temperature sensors (neither shown) are provided at least in the intake pipe 2 and in the heater 1, and the timing for completing the primary heating process and carbonization process described above can be determined based on the measurement value of the former temperature sensor, and the timing for removing the organic waste fuel obtained through the carbonization process can be determined based on the measurement value of the latter temperature sensor.

[0068] Next, the results of the comparative test will be described. Table 1 below shows the results of comparing the bulk density of the target raw material before carbonization with the state of the organic waste fuel obtained after carbonization.

[0069] In Table 1, A shows the results of using waste fermented compost produced by T Co., Ltd. as the target raw material, carrying out the mixing process without the above-mentioned primary heating process, and subjecting the resulting mixture to carbonization. Also, B shows the results of using waste fermented compost produced by S Co., Ltd. as the target raw material, carrying out the mixing process without the above-mentioned primary heating process, and subjecting the resulting mixture to carbonization. Meanwhile, C shows the results of using discarded lunch boxes from a convenience store as the target raw material, carrying out the above-mentioned primary heating process followed by mixing, and subjecting the resulting mixture to carbonization.

[0070] Note that the bulk density shown for A and B was measured on the delivered fermented waste compost, while for C it was measured on the compost that had been cooled to room temperature after the primary heat treatment and before the mixing treatment. The primary heat treatment was performed using a vacuum heater GV-35 (manufactured by Gaia Co., Ltd.) under conditions of a pressure of -0.08 MPa to -0.09 MPa and a temperature of 190°C to 200°C, with the end point being when the exhaust temperature reached approximately 48°C.

[0071] In addition, waste oil generated in a restaurant was used for the mixing process, and was added so that the content of each in the mixture was approximately 30% by mass.

[0072] Meanwhile, the carbonization process was also carried out using a vacuum heater GV-35 (manufactured by Gaia Co., Ltd.) under conditions of a pressure of -0.08 MPa to -0.09 MPa and a temperature of 190°C to 200°C. The carbonization process was terminated when the exhaust temperature reached approximately 40°C. Immediately after completion, the lid of the vacuum heater was opened and the state of the organic waste fuel was visually observed.

[0073] [Table 1]

[0074] As is clear from Table 1, the bulk density was A = 0.72 g / ml > C = 0.69 g / ml > B = 0.32 g / ml. On the other hand, in the state of the organic waste fuel obtained after carbonization, no signs of danger, such as the generation of white smoke, were observed in A and C. In contrast, in B, the obtained organic waste fuel ignited a short time after the lid of the vacuum heater was opened.

[0075] From the above, it can be said that in order to safely handle the organic waste fuel obtained after the carbonization process is completed, it is necessary to use target raw materials with a bulk density of at least 0.32 g / ml.

[0076] (Second Mode for Carrying Out the Invention) Next, a second embodiment of the invention will be described. FIG. 6 is a flow chart showing the procedure for producing organic waste fuel according to the second embodiment of the present invention.

[0077] As mentioned above, for target materials that do not require primary heating treatment, if the bulk density is low, there is a risk that the organic waste fuel may not be able to be handled safely, so after the carbonization treatment is completed, post-treatment must be carried out, in which a non-flammable gas is filled and a cooling operation is performed. Therefore, as a result of extensive research into making it possible to handle organic waste fuel safely without carrying out such post-treatment, we have completed the production method shown in Figure 6.

[0078] That is, as before, it is determined whether or not primary heating treatment is required for the target raw material (step S50), and if it is determined that primary heating treatment is required, the process proceeds to the aforementioned step S41 (see Figure 1) and the primary heating treatment is carried out.

[0079] On the other hand, if it is determined in step S50 that primary heat treatment is not required, the bulk density of the target raw material is measured (step S51). It is determined whether the measured bulk density value is less than the aforementioned threshold value (step S52). If the measured bulk density value is less than the threshold value, a target raw material that does not require primary heat treatment or a product that has been primarily heat-treated and whose bulk density is relatively greater than the threshold value is added (step S53), and the two are thoroughly mixed (step S54). Returning to steps S51 and S52, the bulk density of the resulting mixed raw material is measured, and it is determined whether the measured bulk density value is less than the aforementioned threshold value. The operations from step S51 to step S54 are repeated until it is determined in step S52 that the bulk density value of the mixture exceeds the threshold value.

[0080] Then, when it is determined that the bulk density value of the mixed raw material exceeds the threshold value, the same operations as those in steps S42 to S44 described above are performed to add fats and oils, mix, and carbonize the material (steps S61 to S63), and then the material is removed from the vacuum heater to obtain organic waste fuel (step S64).

[0081] In this way, when fats and oils are mixed with a mixed raw material whose bulk density value exceeds a threshold value to obtain a mixture, and the obtained mixture is then carbonized, there is no risk of white smoke being generated even when the mixture comes into contact with outside air after the carbonization process is completed, and organic waste fuel can be produced more safely even when waste fermented compost is used as the target raw material.

[0082] Next, the results of the comparative test will be described. Table 2 below shows the results of comparing the bulk density of the mixed raw material with the state of the organic waste fuel obtained after carbonization.

[0083] In the comparative tests, the target raw materials used were a mixture of B shown in Table 1, i.e., waste fermented compost produced by S Corporation that was not subjected to the primary heat treatment described above, and C shown in Table 1, i.e., discarded boxed lunches from convenience stores that were used as the target raw material and subjected to the primary heat treatment described above, in an appropriate ratio. In Table 2, D shows the results when the mass ratio of the former to the latter was 35:65, and E shows the results when the mass ratio of the former to the latter was 50:50.

[0084] [Table 2]

[0085] As is clear from Table 2, the bulk density of D was 0.52 g / ml, and no white smoke was observed after carbonization. In contrast, the bulk density of E was 0.42 g / ml, and smoke was observed a few minutes after contact with the outside air following carbonization. However, unlike C in Table 1, no ignition was observed with E, which shows that safety improves as the bulk density of the target raw material increases.

[0086] Based on the above results and past experience, it was thought that the bulk density threshold for the target raw material that has not undergone primary heat treatment, or the bulk density threshold for the mixed raw material of the target raw material and raw material that has undergone primary heat treatment, is at least 0.50 g / ml, which is approximately 5% smaller than the bulk density of D, which is 0.52 g / ml.

[0087] In this embodiment, a case has been described in which a target raw material that is not subjected to primary heat treatment and has a bulk density below a threshold value is mixed with a primary heat-treated product obtained by performing primary heat treatment, such as discarded lunch boxes from a convenience store. However, the present invention is not limited to this, and it goes without saying that a target raw material that is not subjected to primary heat treatment and has a bulk density above a threshold value may also be mixed. [Explanation of symbols]

[0088] 1 Heater 2 intake pipe 3 Cylinders 4 Cooling tank 5. Vacuum pump 6. Cyclone 7. Stirring motor 8 Drive pulley 11 Through shaft 12 driven pulley 13 Inlet lid 14 Cover for outlet 15 Plug heater

Claims

1. A mixture is obtained by mixing a target raw material composed of organic waste other than waste oil with fats and oils, and the mixture is heated in an oxygen-limited environment to carry out a carbonization process in which a portion of the organic compounds constituting the mixture are thermally decomposed, thereby producing organic waste fuel. For the target raw material, based on the moisture content of the target raw material, determine whether or not a primary heating process is necessary to heat the target raw material and reduce the moisture content to a predetermined value, and if it is determined that the primary heating process is not necessary, measure the bulk density of the target raw material and determine whether or not the obtained bulk density value is equal to or less than a predetermined threshold value; If the content is not below the threshold value, or if it is determined that primary heating treatment is necessary, the primary heating treatment is carried out, followed by the mixing treatment and carbonization treatment. On the other hand, if the measured bulk density value is equal to or less than the threshold value, the mixing process and carbonization process are carried out, and whether or not the carbonization process has been completed is determined, for example, based on the exhaust temperature of the carbonization process. The carbonization process is carried out until it is determined to have been completed, and if it is determined to have been completed, a non-combustible gas is introduced into the obtained organic waste fuel, and the organic waste fuel is cooled in an atmosphere of the introduced non-combustible gas. A method for producing organic waste fuel, comprising:

2. A primary heat-treated product obtained by carrying out the primary heat treatment and / or a target raw material determined not to require primary heat treatment, the target raw material having a bulk density exceeding the threshold value, is obtained in advance; If it is determined that primary heat treatment is unnecessary and the bulk density value obtained by measuring the target raw material is equal to or less than the threshold value, the primary heat treatment product and / or the raw material are added to the target raw material until the bulk density value obtained by measurement exceeds the threshold value, and the mixing treatment and carbonization treatment are carried out. If it is determined that the carbonization treatment has been completed, an organic waste fuel is obtained without introducing a non-combustible gas into the obtained organic waste fuel. The method for producing organic waste fuel according to claim 1.

3. 3. The method for producing organic waste fuel according to claim 1, wherein the threshold value is at least 0.50 g / ml.

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