JP2024067080A - Waste treatment method and waste treatment plant - Google Patents

Abstract

[Problem] To recycle waste into something that is expected to be in high demand and is easy to use. [Solution] The waste treatment method includes a fermentation and drying process (step S10) in which waste 1 is aerobically fermented and dried to produce a fermented and dried product 20, and a pyrolysis process (step S130) in which a fermented and dried light product 22 selected from the fermented and dried product 20, i.e., a part of the fermented and dried product 22, is heated to produce pyrolysis oil 220. [Selected Figure] Figure 1

Description

The present invention relates to a waste treatment method and waste treatment plant that uses aerobic fermentation and drying to recycle waste generated in homes, restaurants, traditional Japanese restaurants, hotels, supermarkets, etc., which is a mixture of food waste, paper, plastic, etc. In particular, the present invention relates to a waste treatment method and waste treatment plant that can provide recycled materials such as pyrolysis oil (reproduced oil).

Most of the combustible waste (burnable waste) generated by households, restaurants, Japanese restaurants, hotels, supermarkets and other food and beverage service industries, schools and other business establishments, including food waste such as raw vegetables, fruit and meat, general waste including paper, cloth and small plastics, and household waste, is collected and separated into several types using methods designated by local governments, and then incinerated at incineration sites.
However, in recent years, from the viewpoint of environmental burden, efforts have been made to reduce the amount of incineration by reusing general waste, including organic waste such as food waste, as resources, and active attempts are being made to move from incineration to thermal recycling, chemical recycling, material recycling, etc. For example, as shown in Patent Documents 1 and 2, a method is known in which organic waste such as food waste is fermented and dried in an aerobic environment to be recycled as a raw material for organic fertilizer or a raw material for refuse derived fuel (RDF).

Patent No. 6567741 JP 2015-020110 A

However, in the case of solid fuel (RDF) produced by aerobically fermenting and drying general waste, which is combustible garbage including food waste, and then turning the fermented and dried material into solid fuel, the chlorine concentration is high due to inorganic chlorides such as salt derived from food waste and plastic wrap that contains high levels of chlorine. Therefore, its use is limited to those who install combustion boilers that can handle high chlorine, or large paper companies and cement factories that can dilute the chlorine with large amounts of low-chlorine solid fuel such as Refuse Paper & Plastic Fuel (RPF).

Therefore, because RDF is a solid fuel, its consumption and demand are limited, if there are no demands for the solid fuel (installers of high-chlorine combustion boilers, large paper companies, cement plants, etc.) near the solid fuel production plant, it must be transported to a distant demand destination, which incurs costs for transportation. Furthermore, because RDF is a solid fuel, it is bulky and takes up space to store. This means that there are high costs for transportation and storage, and considering the total energy consumption, its usefulness may decrease, which could hinder the spread of waste-to-energy plants.

The present invention aims to provide a waste treatment method and waste treatment plant that recycles waste into something that is likely to be in high demand and is easy to use.

The waste treatment method of the invention of claim 1 involves a fermentation and drying process in which waste is aerobically fermented and dried to produce a fermented and dried product, and a pyrolysis process in which the fermented and dried product is heated to produce pyrolysis oil.

In the fermentation and drying process, for example, the waste is aerobically fermented in an airtight housing that allows air to be introduced from outside and exhausted to the outside and prevents odor leakage by controlling the negative pressure, and the waste is dried by removing moisture using the heat of fermentation. Preferably, the progress of aerobic fermentation and drying of the waste is promoted by blowing air onto the waste. Also, uniform aerobic fermentation is promoted by spraying water on the waste during fermentation. Furthermore, preferably, a portion of the fermented and dried product is mixed with the waste as a fermentation aid, and more preferably, a desalted fermentation aid is mixed with the waste to efficiently ferment and dry the waste.

In the above pyrolysis process, the fermented and dried product obtained by aerobically fermenting and drying the waste is heated to pyrolyze the hydrocarbon content in the fermented and dried product, and the vaporized oil component (pyrolysis gas) is cooled and condensed, i.e., the hydrocarbon content in the fermented and dried product is converted into oil to obtain pyrolysis oil (product oil). The temperature at which the fermented and dried product is heated at this time may be any temperature at which the hydrocarbon content of the waste can be pyrolyzed, and is preferably greater than 300°C and less than 700°C, and more preferably greater than 350°C and less than 700°C. The heating method is not particularly limited, and may be an electric heating method using an electric heater or the like, a burner heating method, a superheated steam method, a high-frequency induction heating method, or an electromagnetic induction method.

The waste referred to above includes general household waste, such as food waste and paper scraps that are burnable and generated from homes and businesses, office waste, and industrial waste, such as food waste and organic waste such as animal and food residues. It mainly includes organic waste such as food waste, paper, fiber, and plastic.

The waste treatment method of the invention of claim 2 uses the residue remaining after the pyrolysis oil is separated from the fermented and dried product in the pyrolysis process as a raw material for solid fuel RDF (Refuse Derived Fuel: RDF).

The waste treatment method according to the present invention further comprises a desalting step of desalting the fermented and dried product prior to the pyrolysis step.
The above-mentioned desalting process removes salts derived from the waste. For example, the fermented and dried product may be desalted by washing with water to dissolve and remove inorganic chloride salts such as sodium chloride (NaCl), calcium chloride ( _CaCl2 ), magnesium chloride ( _MgCl2 ) contained in the waste food waste (food residues) in water; or salts of organic chlorine compounds such as vinylidene chloride (PVDC) and vinyl chloride (PVC) contained in the waste food wrap, tablet packaging sheets, etc. may be thermally decomposed and removed by heating at 250°C or higher and 300°C or lower; or both may be performed.

The waste treatment plant of the invention of claim 4 comprises a fermentation and drying treatment section that aerobically ferments waste and dries it to produce a fermented and dried product, and a pyrolysis device that heats the fermented and dried product to produce pyrolysis oil.

The fermentation and drying treatment section may be any device that aerobically ferments waste and dries it using the heat of fermentation. For example, it may be configured as an aerobic fermentation and drying device equipped with an airtight housing that allows air to be introduced from the outside and exhausted to the outside using a fan (blower) or the like, and that prevents odor leakage by controlling the negative pressure. Preferably, it is equipped with an air blower that supplies air to the waste, and blows air onto the waste placed stationary in the housing, promoting the progress of aerobic fermentation and drying of the waste. It is also preferably equipped with a watering means that sprays water onto the waste during fermentation, promoting uniform aerobic fermentation of the waste. Furthermore, it is preferable that a portion of the fermented and dried product is mixed with the waste as a fermentation aid, and more preferably, a desalted fermentation aid is mixed with the waste, and the waste is efficiently fermented and dried.

The pyrolysis device generally has a pyrolysis tank (reaction tank) equipped with a heating means, and a cooler for cooling and liquefying the pyrolysis gas produced in the pyrolysis tank. The fermented and dried waste material is fed into the pyrolysis tank and heated there to pyrolyze the hydrocarbons in the fermented and dried product, and the vaporized oil component (pyrolysis oil) is cooled and condensed in a cooler to obtain pyrolysis oil (product oil). The temperature at which the fermented and dried product is heated at this time may be any temperature at which the hydrocarbons in the waste material can be pyrolyzed, and is preferably above 300°C and below 700°C, and more preferably 350°C to 700°C. The heating means is not particularly limited, and may be an electric heating system using an electric heater or the like, a burner heating system, a superheated steam system, or a high-frequency induction heating system.

The waste treatment plant of the invention of claim 5 uses the residue remaining after the pyrolysis oil is separated from the fermented and dried product as a raw material for solid fuel RDF (Refuse Derived Fuel).

The waste treatment plant according to the present invention further comprises a desalting means for desalting the fermented and dried product prior to the pyrolysis.
The above-mentioned desalting means is for removing salts derived from the waste, and may involve, for example, a desalting process in which the fermented and dried product is washed with water to dissolve and remove inorganic chloride salts such as sodium chloride (NaCl), calcium chloride ( _CaCl2 ), magnesium chloride ( _MgCl2 ) contained in food waste (food residues) in the waste, or a heating process at 250°C or higher and 300°C or lower to thermally decompose and remove salts of organic chlorine compounds such as vinylidene chloride (PVDC) and polyvinyl chloride (PVC) contained in food wrap, tablet packaging sheets, etc. in the waste, or both of these processes may be carried out.

According to the waste treatment method of the invention of claim 1, in the fermentation and drying step, the waste is aerobically fermented and dried to produce a fermented and dried product, and in the pyrolysis step, the fermented and dried product is heated at a predetermined temperature to produce pyrolysis oil. The pyrolysis oil produced in this way contains heavy oil and light oil, and is easy to use as fuel, so there is expected to be a large demand for it. That is, the pyrolysis oil produced by oiling the hydrocarbon content of the fermentation and drying product has a density of 0.7 to 0.9, which is equivalent to heavy and light oil, and is denser than the density of the solid fuel RDF produced from the fermentation and drying product, and since it is liquid, combustion control is easy, and it does not require much storage space and is not expensive to store.
Thus, in the waste treatment method according to the first aspect of the present invention, waste is recycled into easily usable pyrolysis oil, which is expected to be in high demand.

According to the waste treatment method of the invention of claim 2, the residue obtained by separating the pyrolysis oil from the fermented and dried product in the pyrolysis process is used as a raw material for solid fuel (RDF), so in addition to the effect of claim 1, the recycled waste materials can be diversified and deployed for multiple uses.

According to the waste treatment method of the invention of claim 3, the fermented and dried product is desalted in a desalting process prior to the pyrolysis process, so that the residual chlorine in the pyrolysis oil generated from the desalted fermentation and drying product is reduced. Therefore, in addition to the effect of claim 1, the quality of the pyrolysis oil (produced oil) can be improved.

According to the waste treatment plant of the invention of claim 4, the waste is aerobically fermented and dried in the fermentation and drying treatment section to produce a fermented and dried product, and the fermented and dried product is heated at a predetermined temperature in the pyrolysis device to produce pyrolysis oil. The pyrolysis oil produced in this way contains heavy oil and light oil, and is easy to use as fuel, so it is expected to be in high demand. That is, the pyrolysis oil produced by oiling the hydrocarbon content of the fermentation and drying product has a density of 0.7 to 0.9, which is equivalent to heavy and light oil, and is denser than the density of the solid fuel RDF produced from the fermentation and drying product, and since it is liquid, combustion control is easy, and it does not require much storage space and is not expensive to store.
Thus, in the waste treatment plant of claim 4, waste is recycled into easily usable pyrolysis oil, which is expected to be in high demand.

According to the waste treatment plant of the invention of claim 5, the residue remaining after the pyrolysis oil is separated from the fermented and dried product is used as a raw material for solid fuel (RDF), so in addition to the effect of claim 4, it is possible to diversify recycled waste materials and develop them for multiple uses.

According to the waste treatment plant according to the invention of claim 6, the fermented and dried product is desalted by a desalting means before the pyrolysis, so that the residual chlorine in the pyrolysis oil produced from the desalted fermented and dried product is reduced. Therefore, in addition to the effect of claim 4, the quality of the pyrolysis oil (produced oil) can be improved.

FIG. 1 is a flow chart of a waste treatment method and a waste treatment process in a waste treatment plant according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of the sorting and desalination processes of the fermented and dried products in the waste treatment method and waste treatment plant according to the embodiment of the present invention. FIG. 3 is a conceptual diagram showing an example of a thermal decomposition apparatus in a waste treatment method and a waste plant according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing another example of a waste treatment method and a pyrolysis apparatus in a waste plant according to an embodiment of the present invention. FIG. 5 is a conceptual diagram showing still another example of a thermal decomposition apparatus in a waste treatment method and a waste plant according to an embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. Note that in this embodiment, the same symbols and reference characters shown in the drawings indicate the same or corresponding functional parts, and therefore, redundant explanations will be omitted here.

[Embodiment]
First, an outline of the overall flow of waste treatment in a waste treatment method and waste treatment plant according to an embodiment of the present invention will be described with reference to Figures 1 and 2. The waste treatment method and waste treatment plant according to the present embodiment are applied to waste recycling for recycling waste 1 such as food waste, paper, cloth, plastic, etc., discarded from general households, etc., into pyrolysis oil (product oil) 220, refuse derived fuel (RDF) 211, etc.

Waste 1, such as household or business general waste, or organic waste such as food waste and animal and plant residues transported as industrial waste, is discharged as burnable waste (combustible waste) from homes or businesses and collected and transported by a garbage truck. When the waste enters the building of a waste treatment plant, first, in a crushing process (step S1), the dust bags containing the waste 1, such as food waste, paper, plastics, etc., are broken by a crusher. The waste 1 is also crushed and reduced in volume by rough crushing, squashing, etc.
In the subsequent mixing process (step S2), the crushed and reduced-volume waste 1 is mixed with a bulk density adjusting material 2 to create many ventilation gaps in the waste 1 pile to increase the bulk, and a fermentation auxiliary material 3 to which aerobic microorganisms are attached, and the bulk density is adjusted to be within a predetermined range, forming a fermentation material 10.

The bulk density adjusting material 2 to be mixed with the waste 1 may be an organic material of a predetermined size that can bulk up the waste 1 pile and create ventilation gaps within the pile, and preferably is an organic material that is water-absorbent, hygroscopic, and capable of supporting microorganisms, such as wood materials such as wood chips, RDF (Refuse Derived Fuel) as solid fuel 211, or RPF (Refuse Paper & Plastic Fuel) as solid fuel.

Wood materials such as wood chips and solid fuel raw materials are low cost and can easily support aerobic microorganisms, allowing for repeated reuse to promote efficient aerobic fermentation and drying of waste 1. This makes it possible to promote aerobic fermentation of waste 1 at low cost. In particular, as described below, wood materials 24 selected from fermented and dried material 20 obtained by fermenting and drying fermentation material 10 contain a high content of decomposition products such as food waste, so heat (fermentation heat) can be expected from the aerobic fermentation of aerobic microorganisms, and a high promotion effect can be expected for the progress of aerobic fermentation and drying of fermentation material 10.

The fermentation auxiliary material 3 increases the processing efficiency of the aerobic fermentation and drying of the waste 1, and is suitable for the fermented and dried material 20 that has already been aerobically fermented, since it has many aerobic microorganisms attached to it. In particular, in this embodiment, the fermentation auxiliary material 3 is selected and desalted from the fermented and dried material 20 obtained by fermenting and drying the fermentation material 10 containing the waste 1. That is, the fermented and dried fine granules 23 that are separated and selected from the fermented and dried material 20 by particle size and weight selection, separately from the solid fuel raw material 210, etc., are desalted and returned to the aerobic fermentation process of the fermentation material 10 as the fermentation auxiliary material 3 for use.

Next, the fermentation material 10, which has been adjusted to a predetermined bulk density by mixing the waste 1 with the bulk density adjusting material 2 and the fermentation auxiliary material 3, is loaded into the concrete housing of the aerobic fermentation and drying device, which serves as a fermentation and drying processing section, stored in whole or in part inside a building, where it is aerobically fermented and dried for a predetermined number of days as the fermentation and drying process (step S10).

At this time, the aerobic fermentation drying apparatus as the fermentation drying processing section of this embodiment sprinkles (sprays) water on the fermentation material 10 placed stationary in the housing. In this embodiment, the wastewater discharged into the housing, i.e., the wastewater seeping out from the fermentation material 10 containing the waste 1, excess water from sprinkling, etc., is collected and filtered with a filter, and the filtered water is used again to sprinkle (spray) the fermentation material 10 in the housing. In addition, the wastewater discharged from the waste 1 into the building, including the above-mentioned crushing of the waste 1 and the mixing process with the bulk density adjusting material 2 and the fermentation auxiliary material 3, is also collected, filtered with a filter, and the filtered water is used to sprinkle (spray) the fermentation material 10 in the housing.

In other words, in the waste treatment plant of this embodiment, the wastewater discharged into the housing, including the moisture contained in the waste 1 and the water sprayed into the housing where the waste 1 is aerobically fermented, is collected from a drain formed in the bottom of the housing, and the wastewater discharged into the building is also collected from a drain formed in the bottom of the building and passed through a water storage tank and filter to be used as water for the fermentation materials 10 containing the waste 1, resulting in a structure that does not discharge wastewater to the outside.

Thus, in the aerobic fermentation and drying apparatus of this embodiment, wastewater that seeps out from the waste 1 inside the housing and surplus water from watering are collected, and after removing foreign matter with a filter without being discharged to the outside, it is circulated and used as watering repeatedly on the fermentation material 10 containing the waste 1. Since the wastewater generated inside the housing contains aerobic microorganisms, the water that is sprayed from it as water droplets also contains aerobic microorganisms, which allows the aerobic microorganisms to be distributed uniformly over the fermentation material 10, thereby improving the efficiency of treatment by aerobic fermentation. In other words, the spraying of water droplets allows the aerobic microorganisms contained in the water droplets to permeate and uniformly permeate the entire fermentation material 1, enabling efficient aerobic fermentation treatment.
In particular, wastewater from within the housing and wastewater generated from buildings other than the housing are collected and used for watering, so the moisture required by the aerobic microorganisms for efficient aerobic fermentation treatment of the fermentation material 10 can be provided at low cost, the amount of wastewater discharged to the outside can be reduced, and the purification equipment for wastewater can be made smaller or eliminated.

In the housing of the aerobic fermentation and drying apparatus of this embodiment, oxygen is replenished by replacing the air (odor) exhausted with fresh air from within the building, and the interior of the housing is controlled to a specified temperature and negative air pressure. In addition, indoor air is drawn in from the top of the housing by a fan (blower), compressed, and ejected from the bottom of the housing to form an air circulation section that circulates air within the housing, providing ventilation for the fermentation materials 10 loaded into the housing.

In this embodiment, the amount of air discharged from the housing of the aerobic fermentation drying apparatus is set to be greater than the amount of air input into the housing, and negative pressure is maintained inside the housing to eliminate the possibility of odors escaping outside the housing. However, the air (odor) discharged from the housing is deodorized in a biological deodorizer via an air plenum chamber before being exhausted to the outside.
That is, the humid air (odor) discharged from the housing is sent from the housing to an air plenum chamber, where it is mixed with air taken in from inside the building outside the housing, and then sent to a biological deodorizing device in the deodorizing equipment installed outside the building.

The biological deodorizing device of this embodiment is equipped with a biofilter made of a pile of carriers such as wood chips with aerobic microorganisms attached thereto, and by passing the mixed air sent from the air plenum chamber through the biofilter, the odorous components contained in the mixed air are decomposed and deodorized by aerobic fermentation of the aerobic microorganisms in the biofilter, and then exhausted (discharged) to the outside, i.e., the outdoor atmosphere. In such a biological deodorizing device that performs deodorization by digestion through biological treatment by aerobic microorganisms, the malodorous gas exhausted from the aerobic fermentation and drying device is decomposed into harmless substances such as _CO2 and _H2O , and inorganic ions such as _SO4- ^and _NO3- , and then discharged, but at this time, no residue that requires post-treatment is generated, and since ^it is not incinerated, the emission of _CO2 and _NOx is also minimized.

In the biological deodorizing device of this embodiment, water is sprayed on the biofilter, and the excess water from the spray is collected and reused as spray water. This allows the moisture necessary for the activity and growth of aerobic microorganisms attached to carriers such as wood chips that decompose and consume odors to be uniformly added and replenished, resulting in stable deodorizing efficiency. In particular, since the excess water from the spray that passes through the biofilter and is collected contains aerobic microorganisms, the water that is sprayed as droplets also contains aerobic microorganisms, which allows the aerobic microorganisms to be uniformly distributed on the biofilter, thereby improving the digestion efficiency through aerobic fermentation. In other words, by spraying droplets of circulating water, the aerobic microorganisms contained in the droplets penetrate and uniformize the entire biofilter, enabling efficient odor treatment. Furthermore, since the excess water from the spray is collected and reused, the moisture necessary for the aerobic microorganisms for stable deodorizing efficiency can be provided at low cost, and since the excess water from the spray on the biofilter is not discharged to the outside, the purification equipment for wastewater can be made small-scale or unnecessary.

Thus, in the waste treatment plant of this embodiment, waste 1 is treated inside a building that is always kept at negative pressure, and aerobic fermentation and drying of fermentation materials 10 is carried out inside an aerobic fermentation and drying device stored inside the building that is kept at a negative pressure higher than the outside, blocking the air flow from the outside to the inside of the room and preventing odor leakage. The air (odor) inside the housing is deodorized by passing through an air plenum room and through a biofilter made of carriers such as wood chips filled in a tank in a biological deodorization device installed outdoors, and is then exhausted into the atmosphere. Therefore, there is no emission of bad odors or uncontrollable odor leakage.

Incidentally, in the fermentation process by microorganisms in the aerobic fermentation and drying equipment (static type), bacteria, filamentous fungi, etc. actively decompose easily decomposable organic substances in the waste 1, such as proteins, amino acids, and carbohydrates, during the first few days, raising the temperature of the waste 1 and, by extension, the temperature inside the housing. When the easily decomposable substances are consumed and the temperature rises, thermophilic aerobic actinomycetes, etc., become involved in the decomposition of the organic matter, and the decomposition of hemicellulose and cellulose begins, and the temperature reaches a maximum of 60°C to 80°C. This high-temperature environment kills various bacteria, thereby sanitizing the treated material. Pathogens, etc. are usually sterilized at 55°C or higher for three days, preferably 65°C or higher for 48 hours or more. Next, the medium temperature range of 30°C to 50°C is maintained to further promote the decomposition of the organic matter. After that, the amount of air taken into the housing from outside the housing is increased to promote cooling and drying.

Thus, in the fermentation and drying process (step S10), the waste 1 is decomposed by aerobic microorganisms, aerobic fermentation proceeds, and drying proceeds due to fermentation heat and aeration. That is, in this fermentation and drying process (step S10), oxygen and the organic matter of the waste 1 are consumed by aerobic microorganisms such as bacteria and filamentous fungi to produce carbon dioxide and energy (heat), and the heat generated here raises the temperature of the fermentation material 10 containing the waste 1, drying the fermentation material 10. Note that waste 1 with a normal composition (20% organic waste, 60% total moisture content) is reduced in volume to roughly half by decomposition and moisture removal during fermentation and drying.

Then, the fermented and dried material 20 that has been aerobically fermented and dried in the aerobic fermentation and drying device, i.e., the fermented and dried material 20 that has been aerobically fermented by aerobic microorganisms and dried by the fermentation heat and ventilation (air blowing), is relayed by a wheel loader or the like in this embodiment as shown in Figures 1 and 2, and in the subsequent sorting process (step S20), it is sorted based on criteria such as size (particle size) and gravity (specific gravity) into a fermented and dried heavy material 21 of a specified oversize that mainly contains the wood material 24 used as the bulk density adjusting material 2, a fermented and dried light material 22 of a specified oversize that is to be converted into oil, and a fermented and dried fine granules of a specified undersize that are mainly used as a fermentation auxiliary material 3.

Specifically, in this embodiment, the fermented and dried material 20 is first sorted by a particle size and weight sorter using buoyancy caused by a predetermined air flow and by weight (specific gravity) and particle size (particle size) using a sieve with a predetermined mesh size. The particle size and weight sorter combines particle size sorting using a screen S such as a trommel screen, star screen, or vibrating sieve, with wind sorting (weight sorting). The air flow introduced into the particle size and weight sorter is then guided to a cyclone C, where the vortex current causes the dust to fall and be removed, and the air from which the dust has been removed is discharged from the top of the cyclone C. It is also effective to use a fan to suck the dust from the output side of the cyclone C.

This sorting machine separates the fermented and dried material 20 into fermented and dried heavy material 21 of a specified oversize (size that does not pass through a sieve with a specified mesh size) and above a specified weight, mainly containing wood materials 24 such as large wood chips (wooden pieces) that are reused as bulk density adjusting material 2, fermented and dried light material 22 of a specified oversize (size that does not pass through a sieve with a specified mesh size) and below a specified weight, mainly containing decomposition products such as paper, plastic, and food waste, and fermented and dried fine granules 23 of a specified undersize (size that passes through a sieve with a specified mesh size) mainly containing decomposition products such as food waste.

The fermented and dried heavy material 21, which is over a certain size and has a certain weight or more, selected by the grain size and weight sorter, mainly contains wood materials 24 such as large wood chips (wooden pieces) used as bulk density adjusting material 2. Metals 310 such as iron are selected and removed by magnetic sorting using a magnetic sorter M (step S21), and non-combustible materials 320 such as bottles, glass, pottery, and stones are selected and removed by manual sorting (artificial sorting) (step S22). The remainder after removing the metals 310 and non-combustible materials 320 is recovered as wood materials 24 to be used as bulk density adjusting material 2 for the untreated waste 1 to be aerobically fermented next time, and is reused as bulk density adjusting material 2 for the waste 1 to be fermented and dried. The metals 310 such as iron and non-combustible materials 320 removed by such sorting processes as magnetic sorting and manual sorting are recycled or disposed of. In addition, vinyl chloride 330 may be sorted out by optical sorting using near-infrared rays or the like before the pyrolysis step (step S130). This allows the chlorine concentration of the resulting pyrolysis oil 220 and solid fuel RDF 220 (described below) to be reduced with less energy consumption, making it possible to produce higher quality pyrolysis oil 220 and solid fuel RDF 220.

Furthermore, the fermented and dried fine granules 23 of a certain undersize sorted by the particle size and weight sorting machine mainly contain decomposition products such as food waste, and therefore contain seed bacteria (aerobic microorganisms) that aerobically ferment the waste 1. The fermentation aid 3 is recovered as a suitable material for efficiently promoting the aerobic fermentation and drying of the waste 1.

In particular, in this embodiment, the fermented and dried fine granules 23 of a certain undersize sorted by the particle size and weight sorting machine are desalted in the desalting process (step S30) and then used as the fermentation auxiliary material 3 to be mixed with the untreated waste 1 in the next cycle.
By washing the fermented and dried fine granules 23 selected from the fermented and dried material 20, the water-soluble chlorides contained in the fermented and dried fine granules 23 can be dissolved in water and removed, and the salt concentration of the fermented and dried fine granules 23 can be significantly reduced. By washing the fermented and dried fine granules 23 to reduce the salt concentration of the fermented and dried fine granules 23, even when the fermented and dried fine granules 23 are returned to the fermentation and drying process of the untreated fermentation material 10 in the fermentation and drying step (step S10) and are repeatedly used as the fermentation auxiliary material 3, the fermented and dried material 20 obtained by fermenting and drying the fermentation material 10 does not experience salt concentration or accumulation, and the salt concentration of the fermented and dried material 20 can be maintained at a low concentration, and stable fermentation and drying efficiency can be maintained. As a result, the salt concentration of the fermented and dried light material 22 selected from the fermented and dried material 20 and to be converted into oil can also be kept low. Therefore, the residual chlorine (chlorine fraction) in the pyrolysis oil (product oil) 220 produced by heating the recycled raw material 210 is also extremely small, making it possible to supply high-quality product oil 220 and solid fuel (RDF) 211.

That is, if "chlorine concentration of waste 1/(1-weight loss rate)"<"chlorine concentration of fermentation auxiliary material 3" (weight loss rate: {weight of fermentation material 10-weight of fermentation dried product 20}/weight of fermentation material 10), salt will be concentrated and accumulated in the fermentation dried product 20 during the fermentation drying process (step S10) of the fermentation material 10 to which the fermentation auxiliary material 3 has been added. In other words, when the fermentation dried fine granules 23, which is a part of the fermentation dried product 20, are returned (circulated) as the fermentation auxiliary material 3 to be mixed with the fermentation material 10 and used repeatedly, if the salt concentration of the fermentation auxiliary material 3 is higher than that of the waste 1, the salt concentration of the fermentation material 10 will gradually increase, causing fermentation inhibition due to high salt, and there is a risk that stable fermentation and drying efficiency will not be maintained in the batch-type aerobic fermentation process of the waste 1.
In this embodiment, the fermented and dried fine granules 23 are desalted by washing with water before being used as the fermentation auxiliary material 3 to be mixed with the waste 1. This makes it possible to maintain the condition of "chlorine concentration of waste 1/(1-weight loss rate)"≧"chlorine concentration of fermentation auxiliary material 3". In the fermentation and drying process of the fermentation material 10 to which the desalted fermented and dried fine granules 23 have been added as the fermentation auxiliary material 3, no salt concentration or accumulation occurs in the fermented and dried material 20 obtained by fermenting and drying the fermentation material 10. This makes it possible to maintain a stable fermentation and drying efficiency in the batch-type aerobic fermentation process of the waste 1.

In particular, in this embodiment, as described above, the water sprayed onto the fermentation material 10 is collected together with the wastewater contained in the waste 1, filtered to remove foreign matter, and then stored in a tank. The water is then reused for spraying and circulated. Since the salt concentration of the water is in equilibrium with the salt concentration of the fermentation material 10, and since the water for spraying does not easily penetrate into the interior of the accumulated fermentation material 10, the salt concentration of the fermentation material 10 does not easily dissolve into the water when sprayed onto the fermentation material 10, it is difficult to sufficiently remove the salt of inorganic chlorides. For this reason, if the fermented and dried fine granules 23 are used as the fermentation auxiliary material 3 without desalination treatment, the fermented and dried material 20 obtained by fermenting and drying the fermentation material 10 containing the fermentation auxiliary material 3 and the waste material 10 will have a higher salt concentration than the waste material 1. If a portion of the fermented and dried material 20, which has a higher salt concentration than the waste material 10, is repeatedly used as the fermentation auxiliary material 3, the newly treated fermentation material 10 will have a higher salt concentration than the previously treated fermentation material 10, and the salt will be concentrated and accumulated in the fermentation material 10, gradually increasing the salt concentration. As the salt concentration increases, fermentation will be inhibited.

However, when the fermented and dried fine granules 23 are desalted by washing with water and then used as the fermentation auxiliary 3 to be mixed with the waste 1, the salt concentration of the fermented and dried fine granules 23 used as the fermentation auxiliary 3 is reduced by the desalting. In particular, the amount of the fermented and dried fine granules 23 is smaller than that of the waste 1 and the fermented and dried material 20, and inorganic chlorides can be removed from the fermented and dried fine granules 23 with a small amount of water. That is, when the fermented and dried fine granules 23 selected from the fermented and dried material 20 and used as the fermentation auxiliary 3 for aerobic fermentation of the waste 1 are desalted by washing with water, the chlorine concentration of the s raw material 210 can be effectively reduced with a small amount of energy consumption without heating and with a small amount of water. Therefore, the salt concentration can be effectively reduced at low cost.
In this way, by mixing the fermented and dried fine granules 23, which have a lower salt concentration than the waste 1, with the waste 1 and then fermenting and drying the waste 1, it is possible to prevent salts from concentrating and accumulating in the fermentation material 10, and also to reduce the salt concentration of the fermented and dried material 20.

In this embodiment, the water washing process for desalting the fermented and dried fine granules 23 selected from the fermented and dried material 20 is carried out by placing the fermented and dried fine granules 23 on a predetermined location such as a conveyor and sprinkling or spraying water over them. The water used in the sprinkling process is water that has a lower salt concentration than the recovered wastewater that is discharged as wastewater (sewage) within the housing or building described above. In this embodiment, the water used in sprinkling the fermented and dried fine granules 23 is recovered, and after the dissolved inorganic chlorides are removed, it is circulated again as sprinkling water for the fermented and dried fine granules 23 and used repeatedly.
That is, in this embodiment, the water (excess water) sprayed on the fermented and dried fine granules 23 is recovered, and since inorganic chlorides derived from the waste 1 are dissolved in the water used for spraying the fermented and dried fine granules 23 and recovered, the dissolved inorganic chlorides are removed. The water from which the inorganic chlorides have been removed is filtered to remove foreign matter, and then reused as water to be sprayed on the fermented and dried fine granules 23 for the desalting process of the fermented and dried fine granules 23 in the desalting process (step S30). That is, the water sprayed on the fermented and dried fine granules 23 is circulated and used repeatedly for spraying after the inorganic chlorides have been removed. However, when the present invention is implemented, the water from which the inorganic chlorides have been removed may be treated as sewage and discharged (discharged to the outside) without being reused or circulated as spraying. In this case, the water used for spraying the fermented and dried fine granules 23 for desalting is collected and purified from the spraying of the biofilter, or fresh water (service water) from the outside is taken in and used.

In this embodiment, the fermented, dried, lightweight material 22 that is over a certain size but under a certain weight and is sorted by the particle size and weight sorter is mainly a mixture of decomposition products such as paper, plastic, and food waste, and after metals 310 such as iron are sorted and removed by magnetic sorting using a magnetic sorter M (step S24), the fermented, dried, lightweight material 22 is heated to a certain temperature in a pyrolysis process (step S130) to pyrolyze the hydrocarbons contained in the fermented, dried, lightweight material 22, and the pyrolysis gas is cooled to produce pyrolysis oil (reproduced oil) 220. The residue from which the hydrocarbons have evaporated is used as solid fuel raw material 210 to be used for solid fuel (RDF) 211.

As a pyrolysis device for pyrolyzing (oilification) the fermented and dried light material 22 in the pyrolysis step (step S130), for example, as shown in FIG. 3, a continuous-processing pyrolysis (oilification) device 111A can be used. The continuous-processing pyrolysis device 111A has a pyrolysis tank 110A equipped with a heating means for heating the fermented and dried light material 22 and an extruder 112 for feeding the fermented and dried light material 22 while heating it, a cooler 131 for cooling and condensing the pyrolysis gas generated by the pyrolysis of the hydrocarbon content in the fermented and dried light material 22 by heating in the pyrolysis tank 110A, and an oil tank 134 for recovering the pyrolysis oil (produced oil) 220 generated by condensation in the cooler 131.

The pyrolysis tank 110A is connected to a hopper 111 into which the fermented, dried, lightweight material 22 is fed, and the fermented, dried, lightweight material 22 fed through the hopper 111 is heated to a predetermined temperature by a heating means such as a heater. The hopper 111 into which the fermented, dried, lightweight material 22 is fed may be vibrated constantly or periodically to prevent clogging of the hopper 111. The fermented, dried, lightweight material 22 fed into the hopper 111 may be mixed with an additive (such as hydrated lime) as necessary.

The extruder 112 of the pyrolysis tank 110A is, for example, a screw-type extruder consisting of a heating cylinder with an electric heater (such as a band heater) on the outer periphery as a heating means, and a screw that rotates inside the heating cylinder. The screw is driven to rotate in one direction by an external motor. Note that it may be a single-screw extruder or a twin-screw extruder.

In this embodiment, the pyrolysis tank 110A is composed of a desalting heating section 110a that heats and desalinates the fermented, dried, lightweight material 22 at a low temperature of 250°C or higher and 300°C or lower, and a pyrolysis section 110b that is connected to the desalting heating section 110a and heats the fermented, dried, lightweight material 22 sent from the desalting heating section 110a at a high temperature of more than 300°C and 700°C or lower.

Therefore, the fermented, dried, lightweight material 22 fed from the hopper 111 is first heated to 250°C or more and 300°C or less by an electric heater in the heating cylinder of the desalting heating section 110a, and then sent downstream by the screw of the extruder 112. By heating to 250°C or more and 300°C or less in the desalting heating section 110a, organic chlorine compounds such as polyvinylidene chloride (PVDC) and polyvinyl chloride (PVC) derived from food lamps and the like contained in the fermented, dried, lightweight material 22 are thermally decomposed, and the chlorine and hydrogen in the organic chlorine compounds are desorbed, that is, desalted and oxidized to generate hydrogen chloride gas. In other words, by heating the fermented, dried, lightweight material 22 to 250°C or more and 300°C or less in the desalting heating section 110a, the salt content of the organic chlorine compounds contained in the fermented, dried, lightweight material 22 is removed and desalted. The hydrogen chloride gas (vapor) generated by heating the fermented and dried light material 22 at 250°C or higher and 300°C or lower in the desalting and heating section 110a is discharged from the desalting and heating section 110a, cooled and condensed by the cooler 121 (condenser, cooling condenser), and recovered as hydrochloric acid in the hydrochloric acid tank 124. The gas that passes through the cooler 121 is incinerated (combusted) in the off-gas treatment section 151, or used as fuel, after the hydrogen chloride gas is removed by the hydrogen chloride trap 126 that absorbs the hydrogen chloride gas. The hydrochloric acid recovered in the hydrochloric acid tank 124 can usually be used as an industrial chemical.

Furthermore, the fermented, dried, lightweight material 22, which is heated in the desalting heating section 110a and sent to the downstream pyrolysis section 110b by the screw of the extruder 112, is heated by an electric heater in the heating tube of the pyrolysis section 110b to a temperature exceeding 300°C and not exceeding 700°C, and is sent downstream by the screw of the extruder 112. By heating in the pyrolysis section 110b to a temperature exceeding 300°C and not exceeding 700°C, the fermented, dried, lightweight material 22 is separated into pyrolysis gas and residue. That is, pyrolysis of the hydrocarbon content in the fermented, dried, lightweight material 22 generates pyrolysis gas, which is discharged from the pyrolysis section 110b and separated from the residue after pyrolysis of the fermented, dried, lightweight material 22.

The residue after pyrolysis of the fermented and dried light material 22 is collected in a residue tank 144 as a solid fuel raw material 210 to be used for solid fuel (RDF) 211. The remainder after the chlorine and hydrogen of the organic chlorine compounds in the fermented and dried light material 22 are desorbed is an organic compound or carbonized material that does not contain chlorine atoms.

Meanwhile, the pyrolysis gas generated in the pyrolysis section 110b is discharged from the pyrolysis section 110b, cooled and condensed by a cooler (condenser, cooling condenser) 131, separated into water and oil in an oil-water separator 132, and the oil is recovered as pyrolysis oil (reproduced oil) 220 in an oil tank 134.
That is, the cooler 131 to which the pyrolysis gas generated in the pyrolysis section 110b is supplied cools and condenses the pyrolysis gas with cold water or air to liquefy it. For example, the cooler 131 has a body through which the pyrolysis gas flows and a cooling heat transfer tube disposed within the body, and cools the pyrolysis gas flowing within the body by flowing cooling water inside the cooling heat transfer tube.
The oil and water produced by the liquefaction of the pyrolysis gas is separated into pyrolysis oil 220 (oil) and water in an oil-water separator 132, which separates the liquid oil and water produced by cooling the pyrolysis gas by the cooler 131.In other words, a mixture of the condensed liquid containing low molecular weight hydrocarbons obtained by cooling and substances that become solid by cooling, and the liquid flowing down from the liquid film flowing along the outer surface of the cooling heat transfer tube enters the oil-water separator 132, and the clear liquid of the mixture is separated as pyrolysis oil 220.The separated pyrolysis oil 220 is recovered in an oil tank 134.

Downstream of the cooler 121, which cools the steam generated by heating the fermented and dried lightweight material 22 to 250°C or more and 300°C or less, and the cooler 131, which cools the pyrolysis gas generated by heating the fermented and dried lightweight material 22 to 300°C or more and 700°C or less, an off-gas processing unit 151 is provided, and off-gas components that cannot be condensed in the cooler 121 or the cooler 131 are burned and disposed of, or used as fuel. The off-gas (e.g., combustible gases such as methane, ethane, propane, and butane) that has passed through the coolers 121 and 131 is incinerated (combusted) in the off-gas processing unit 151, or used as fuel. The off-gas may be configured to prevent backflow by providing a trap or the like. In addition, the energy of combustion at this time may be utilized as fuel for supporting combustion in the heating burners of the pyrolysis tank 110A.

The pyrolysis oil 220 thus produced by heating the fermented and dried light material 22 to a temperature exceeding 300°C and not exceeding 700°C can be used as various fuels (e.g., fuel for boilers, generators, heavy machinery, etc.) and is supplied to consumers. In particular, pyrolysis oil 220 has excellent transportability and storability compared to solid fuel RDF, and is also easy to handle as a fuel, and can be used for a variety of purposes as a fuel oil (e.g., fuel for machines such as boilers, generators, heavy machinery, etc.). In addition, a portion of the pyrolysis oil 220 can also be used as fuel for the heating means in the pyrolysis tank 110A.

That is, in the case of the solid solid fuel RDF produced from the fermented and dried light material 22, it takes up a lot of storage space due to its bulkiness, and there is a risk of re-fermentation (secondary fermentation) progressing and generating odors and gases depending on the humidity and temperature during storage, so from the perspective of safety measures, it is necessary to pay attention to the storage and storage location and transportation method, whereas the liquid pyrolysis oil 220 can be stored and transported in a smaller space than the solid fuel RDF, and can be transported, stored, and stored at low cost without worrying about humidity and temperature. The pyrolysis oil 220 produced by pyrolysis (oilification) of the fermented and dried light material 22 has a density of about 0.7 to 0.9, which is equivalent to heavy and light oil, and is high density compared to the density of the solid fuel (RDF) produced from the fermented and dried light material 22, which is about 0.3 to 0.4. Moreover, since it is liquid, combustion control is easier than with the solid fuel (RDF), so it has a wide range of uses and is easy to use, and consumption and demand are expected to be high in the vicinity of the waste disposal plant.
Therefore, even in areas where there are no customers for solid fuel RDF nearby, the pyrolysis oil 220 is more versatile than solid fuel RDF and demand for it is expected, which can lead to the spread of waste plants.

The pyrolysis oil 220 obtained in this manner by heating the fermented, dried light material 22 at a predetermined temperature and pyrolyzing the hydrocarbons in the organic matter contains small amounts of aromatic compounds, oxygen-containing compounds, and highly polar compounds, but also contains a large amount of low-polarity aliphatic compounds, and has high physical properties as a fuel. Even when mixed with petroleum-derived fuels, it is resistant to phase separation and is highly valuable as a fuel.
In addition, when heating the fermented, dried, light material 22, the thermal decomposition easily proceeds at a low temperature without adding a catalyst, and the oil components volatilize, resulting in high energy efficiency. This is presumably because a large number of radicals are easily generated in the fermented, dried, light material 22.

In particular, in this embodiment, before the fermented and dried lightweight material 22 is heated to a temperature exceeding 350°C and not exceeding 700°C to generate pyrolysis gas, the fermented and dried lightweight material 22 is heated to a temperature exceeding 250°C and not exceeding 300°C to perform dechlorination. In other words, the hydrocarbon content of the fermented and dried lightweight material 22 that has been desalted and oxidized is converted into oil. Therefore, the pyrolysis oil (product oil) 220 thus produced has little residual salt, is high in calories, and is of high quality. In addition, the fermented and dried lightweight material 22 from which organic compounds have been desalted and oxidized has desorbed hydrogen, which reduces the by-production of tar, which causes blockage of pipes and inhibits gasification, during pyrolysis by heating to a temperature exceeding 300°C and not exceeding 700°C.

In the above embodiment, the pyrolysis oil 220 is described as a mixture of light oil (gasoline), kerosene, diesel, and heavy oil. However, when implementing the present invention, a separation device (distillation device) may be further provided to separate the pyrolysis oil (product oil) 220 of the mixture into light oil, medium oil, heavy oil, etc., and the light oil separated from the pyrolysis oil 220 may be used as mechanical fuel for heavy machinery, the medium oil as boiler fuel, and the heavy oil as power generation fuel.

In this embodiment, the residue obtained by vaporizing the hydrocarbon content of the fermented dried light material 22 is collected in a residue tank 144 and used as a raw material for the solid fuel RDF (solid fuel raw material 210). The solid fuel raw material 210 of the residue collected in the residue tank 144 can be compressed and packed using a baler (compression packing machine) to facilitate transfer to the solid fuel production process (solid fuel production process).
In the subsequent solid fuel production process, the solid fuel raw material 210 is mixed with a calorific value adjusting material such as dry plastic, wood, paper, cloth, etc., crushed in a crusher, and if necessary, incombustible materials such as iron and stone are removed, and the solid fuel is molded in a molding machine to become solid fuel (RDF) 211. In the molding process, additives such as anti-corrosion agents are added as necessary. Also, odors, water vapor, etc. generated in the solid fuel production process, especially in the molding process, can be sent to a biological deodorizing device, where they are deodorized, and then exhausted to the outside.

In particular, the solid fuel (RDF) 211 thus produced is dechlorinated by heating the fermented, dried, light material 22 at a temperature exceeding 300°C and not exceeding 700°C, preferably at a temperature exceeding 350°C and not exceeding 700°C, before generating pyrolysis gas by heating the fermented, dried, light material 22 at a temperature exceeding 250°C and not exceeding 300°C. In other words, the solid fuel (RDF) 211 produced from the solid fuel raw material 210, which is the residue obtained by turning the hydrocarbon content of the fermented, dried, light material 22 into oil after desalting and oxidation, has a low salt concentration. This makes the solid fuel highly versatile, and an increase in demand for the solid fuel (RDF) 211 is expected. In addition, the solid fuel (RDF) 211 produced from the residue obtained by pyrolyzing the hydrocarbon content of the fermented, dried, light material 22, i.e., the residue after high-temperature treatment, can have a lower moisture content, suppress the progression of re-fermentation (secondary fermentation), and is safer as it is less likely to produce odors or gases due to re-fermentation.

When carrying out the present invention, the pyrolysis apparatus 111A for producing pyrolysis oil 220 from the fermented, dried light material 22 is not limited to a pyrolysis tank 110A in the form of the screw-type extruder described above, i.e., a continuous processing type, but may be, for example, a batch type pyrolysis tank in the form of a reaction kettle 110B, as shown in Figures 4 and 5.
4 also includes a pyrolysis tank (reaction tank) 110B equipped with a heating means for heating the fermented, dried, light material 22, a cooler 131 for cooling and condensing the pyrolysis gas produced by pyrolysis of the hydrocarbons in the fermented, dried, light material 22 by heating in the pyrolysis tank (reaction tank) 110B, and an oil tank 134 for recovering the pyrolysis oil (produced oil) 220 produced by condensation in the cooler 131. In addition, a desalting device 171 is provided upstream of the pyrolysis tank (reaction tank) 110B.

The desalting device 171 heats the fermented, dried, light material 22 supplied through the hopper 111 to a predetermined temperature using a heating means such as a heater, and performs desalting by desalting and oxidizing the organic chlorine compounds in the fermented, dried, light material 22.
This desalting device 171 is equipped with a screw-type extruder 112 consisting of a heating cylinder with an electric heater (such as a band heater) disposed around the periphery as a heating means and a screw rotating inside the heating cylinder, and can supply the fermented, dried, light material 22 to the pyrolysis tank (reaction tank) 110B while heating it. However, when implementing the present invention, the device is not limited to one equipped with the screw-type extruder 112 as long as it can heat the fermented, dried, light material 22 to a predetermined temperature.

The pyrolysis tank (reaction tank) 110B heats the fermented and dried light material 22 supplied from the desalting device 171 to a predetermined temperature using a heating means such as a heater or burner. A stirrer or a drum driven by a motor is installed inside the pyrolysis tank (reaction tank) 110B to uniformly promote the pyrolysis (oilification) of the hydrocarbon content of the fermented and dried light material 22 fed into the pyrolysis tank (reaction tank) 110B.

In this batch-type pyrolysis device 111B, the fermented and dried light material 22 fed from the hopper 111 is first heated to 250°C or higher and 300°C or lower by a heater in the heating cylinder of the desalting device 171, and then sent downstream by the screw of the extruder 112. By heating to 250°C or higher and 300°C or lower in the desalting device 171, organic chlorine compounds such as polyvinylidene chloride (PVDC) and polyvinyl chloride (PVC) derived from food lamps and the like contained in the fermented and dried light material 22 are thermally decomposed, and the chlorine and hydrogen in the organic chlorine compounds are desorbed, that is, desalted and oxidized to generate hydrogen chloride gas. In other words, by heating the fermented and dried light material 22 to 250°C or higher and 300°C or lower in the desalting device 171, the salt content of the organic chlorine compounds contained in the fermented and dried light material 22 is removed and desalted. The hydrogen chloride gas (vapor) generated by heating the fermented and dried light material 22 in the desalting device 171 to 250°C or higher and 300°C or lower is discharged from the desalting device 171, cooled and condensed by the cooler 121 (condenser, cooling condenser), and recovered as hydrochloric acid in the hydrochloric acid tank 124. The gas that passes through the cooler 121 is incinerated (combusted) in the off-gas processing unit 151, or used as fuel, after the hydrogen chloride gas is removed by the hydrogen chloride trap 126 that absorbs the hydrogen chloride gas.

Furthermore, the fermented, dried, lightweight material 22, which is heated in the desalting device 171 and sent downstream by the screw of the extruder 112 and then charged into the pyrolysis tank (reaction tank) 110B, is heated to a temperature exceeding 300°C and not exceeding 700°C by a heater or the like. By heating to a temperature exceeding 300°C and not exceeding 700°C in this pyrolysis tank (reaction tank) 110B, the fermented, dried, lightweight material 22 is separated into pyrolysis gas and residue. That is, pyrolysis of the hydrocarbon content in the fermented, dried, lightweight material 22 generates pyrolysis gas, which is discharged from the pyrolysis tank (reaction tank) 110B and separated from the residue after pyrolysis of the fermented, dried, lightweight material 22.

In the batch-type pyrolysis apparatus 111B, the residue remaining after pyrolysis of the fermented, dried, light material 22 is also recovered in a residue tank 144 as a solid fuel raw material 210 to be utilized as a solid fuel (RDF) 211.
On the other hand, the pyrolysis gas generated in the pyrolysis tank (reaction tank) 110B is discharged from the pyrolysis tank (reaction tank) 110B, cooled and condensed by a cooler (condenser, cooling condenser) 131, separated into water and oil in an oil-water separator 132, and the oil is recovered as pyrolysis oil (reproduced oil) 220 in an oil tank 134.

In the batch-type pyrolysis apparatus 111B shown in FIG. 4, a desalting apparatus 171 equipped with a screw-type extruder 112 is provided separately from the pyrolysis tank (reaction tank) 110B. However, when implementing the present invention, as in the pyrolysis apparatus 111C shown in FIG. 5, a dehydrochlorination step at a temperature of 250° C. or higher and 300° C. or lower and a high-temperature pyrolysis step at a temperature of more than 350° C. and 700° C. or lower may be performed in the same pyrolysis tank (reaction tank) 110B.
That is, the batch-type pyrolysis apparatus 111C shown in FIG. 5 also has a pyrolysis tank (reaction tank) 110B equipped with a heating means for heating the fermented, dried light material 22, a cooler 131 for cooling and condensing the pyrolysis gas produced by the pyrolysis of the hydrocarbon content in the fermented, dried light material 22 by heating in the pyrolysis tank (reaction tank) 110B, and an oil tank 134 for recovering the pyrolysis oil (produced oil) 220 produced by condensation in the cooler 131, and the fermented, dried light material 22 supplied via the hopper 111 is heated by a heating means such as a heater provided in the pyrolysis tank (reaction tank) 110B.

The heating step is carried out in two stages, first at 250° C. or higher and 300° C. or lower, and second at 300° C. or higher and 700° C. or lower, whereby the former heating step at 250° C. or higher and 300° C. or lower carries out a desalination step of desalination and oxidation of organic chlorine compounds in the fermented, dried, light material 22, and the latter heating step at 300° C. or higher and 700° C. or lower carries out a pyrolysis step of pyrolyzing the hydrocarbon content in the fermented, dried, light material 22. This separates the material into pyrolysis gas and residue.
In the pyrolysis apparatus 111C, hydrogen chloride gas (vapor) generated by heating the fermented and dried light material 22 in the pyrolysis tank (reaction tank) 110B to 250°C or more and 300°C or less is discharged from the pyrolysis tank (reaction tank) 110B, and is cooled and condensed by the cooler 121 and recovered as hydrochloric acid in the hydrochloric acid tank 124, similar to the pyrolysis apparatuses 111A and 111B described above. The gas that has passed through the cooler 121 is incinerated (combusted) in the off-gas treatment unit 151, or used as fuel, after removing the hydrogen chloride gas in the hydrogen chloride trap 126 that absorbs the hydrogen chloride gas. The residue after pyrolysis of the fermented and dried light material 22 by heating to 300°C or more and 700°C or less is recovered in the residue tank 144 as the solid fuel raw material 210 used for the solid fuel (RDF) 211. On the other hand, the pyrolysis gas generated in the pyrolysis tank (reaction tank) 110B by heating the fermented and dried light material 22 to a temperature exceeding 300°C and not exceeding 700°C is discharged from the pyrolysis tank (reaction tank) 110B, cooled and condensed by a cooler 131, and separated into water and oil in an oil-water separator 132. The oil is then recovered in an oil tank 134 as pyrolysis oil (reproduced oil) 220.

In carrying out the present invention, a catalyst tank may be disposed between the pyrolysis tanks (reactors) 110A, 110B and the cooler 132, and the pyrolysis gas generated in the pyrolysis tanks (reactors) 110A, 110B may be further catalytically decomposed using a catalyst for reforming, and the heavy oil and light oil fractions may be separated and recovered.
In addition to the pyrolysis (oilification) of the fermented, dried, lightweight material 22, carbonization may be performed by treatment in an oxygen-free state using steam to generate a carbonized residue. That is, the pyrolyzed residue of the fermented, dried, lightweight material 22 may be collected as a carbonized material. Such a carbonized residue can be used, for example, as a deodorizer, a humidity control material, an anti-mite/anti-fungal material, eco-cement, a water purification agent, a soil improvement material, and the like.

In addition, when carrying out the present invention, before thermally decomposing organic chlorine compounds such as vinylidene chloride (PVDC) and vinyl chloride (PVC) contained in the fermented, dried, lightweight material 22 by heating at 250° C. or higher and 300° C. or lower, a water washing treatment may be performed in which inorganic chlorides such as sodium chloride (NaCl), calcium chloride (CaCl ₂ ), magnesium chloride (MgCl ₂ ), etc. derived from food waste and the like contained in the fermented, dried, lightweight material 22 are dissolved in water and desalted by spraying water on the fermented, dried, lightweight material 22. That is, the fermented, dried, lightweight material 22 from which the inorganic chlorides have been removed by the water washing treatment may be heated at 250° C. or higher and 300° C. or lower to dechlorinate and oxidize the organic chlorine compounds, and then heated at a temperature exceeding 300° C. and 700° C. or lower to thermally decompose the hydrocarbons to produce the pyrolysis oil 220.
In this way, the pyrolysis oil 220 produced from the fermented and dried light material 22, which has been subjected to the water washing process to remove inorganic chlorides and the heat treatment at a predetermined temperature to remove chlorine from organic chlorine compounds, has less residual chlorine and is of higher quality. Furthermore, the salt concentration in the pyrolysis residue of the fermented and dried light material 22 can be reduced, which increases its versatility.

Thus, in this embodiment, the fermented and dried light material 22 selected from the fermented and dried material 20 obtained by drying the waste 1 through aerobic fermentation is heated at a predetermined temperature to pyrolyze the hydrocarbon content, thereby producing pyrolysis oil (product oil) 220. The residue from which the hydrocarbon content has evaporated becomes solid fuel raw material 210 that is used for solid fuel (RDF) 211.

In this embodiment, the waste 1 is dried by aerobic fermentation, and then the solid fermented and dried matter 20 (fermented and dried light matter 22) is heated at a predetermined temperature to pyrolyze the hydrocarbon content, thereby generating pyrolysis oil (resulting oil) 220. Since no heating energy is required for drying and reducing the volume of the waste 1, and the fermented and dried matter 20 with reduced moisture content is heated at a high temperature, the pyrolysis oil (resulting oil) 220 can be recovered with a high combustion efficiency and a small amount of heating energy. The pyrolysis oil 220 generated by the pyrolysis of the fermented and dried matter 20 of the waste 1 is more convenient to use as fuel than solid fuel (RDF). Furthermore, the residue from which the hydrocarbon content of the fermented and dried matter 20 is vaporized becomes solid fuel material 210 that can be used for solid fuel (RDF) 211, so that a recycled material that can be used for other purposes can be formed.

In this way, the waste treatment method and waste treatment plant of this embodiment ferments waste 1, which is a mixture of food waste, plastic, paper, cloth, etc., aerobically and dries it using the heat of fermentation and ventilation to produce a fermented and dried product 20, and the fermented and dried light material 22 selected from the fermented and dried product 20 is separated into pyrolysis gas and residue by heating at a predetermined temperature, the resulting pyrolysis gas is condensed and recovered as pyrolysis oil (reproduced oil) 220, and the residue is recovered as solid fuel raw material 210 used for solid fuel (RDF) 211, and recycled into pyrolysis oil (reproduced oil) 220 and solid fuel (RDF) 211.

In other words, the waste treatment method and waste treatment plant of this embodiment aerobically ferment and dry the waste 1, and then produce pyrolysis oil 220. Compared to solid fuel RDF, pyrolysis oil 200 has fewer limitations on its use and is easier to use and consume, making it possible to expand its uses as a fuel.
Thus, the waste treatment method and waste treatment plant of this embodiment convert the waste 1 into a recycled material (chemically recycled product) of pyrolysis oil 220 which is expected to be in high demand and is easy to use, that is, recycles the waste 1 into pyrolysis oil 220 which is expected to be in high demand and is easy to use. In addition, the residue obtained by pyrolysis of the hydrocarbon content of the fermented and dried product 20 can be used as the raw material 210 for the solid fuel RDF and can also be recycled as the solid fuel RDF 211, so that the recycled material of the waste 1 can be used for multiple purposes.

In particular, in the waste treatment method and waste treatment plant of this embodiment, a part of the fermented and dried matter 20, i.e., the fermented and dried fine granules 23 selected by particle size and weight from the fermented and dried matter 20, is mixed (returned) as the fermentation auxiliary material 3 with the waste 1 to be aerobically fermented and dried, and the waste 1 is aerobically fermented to promote aerobic fermentation and drying. The fermented and dried fine granules 23 used as the fermentation auxiliary material 3 are selected from the fermented and dried matter 20, and then subjected to a desalination process in which the inorganic chlorides contained in the fermented and dried fine granules 23 are dissolved in water by a water washing process, so that the chlorine concentration is reduced. In addition, the fermented and dried light matter 22 selected from the fermented and dried matter 20 is heated at a predetermined low temperature to desalinate the chlorine of the organic chlorine compounds, and then pyrolyzed. Therefore, the pyrolysis oil (produced oil) 220 produced by the pyrolysis has a low residual chlorine content, and the remaining residue that is not pyrolyzed also has a low salt concentration. This makes it possible to provide pyrolysis oil (refined oil) 220 with low residual chlorine and solid fuel (RDF) 211 with low salt concentration, which can be used for other purposes and produce high-quality recycled materials.

In the above embodiment, dechlorination is performed using an extruder method with a specified heating before the pyrolysis process, which results in a high desalted chlorine rate and a short reaction time for dechlorination, making dechlorination efficient. However, when implementing the present invention, desalting treatment may also be performed using a rotary kiln method, a melting tank (kettle) method, or a catalytic method.

As described above, the waste treatment method of the above embodiment includes a fermentation and drying process (step S10) in which waste 1 is aerobically fermented and dried to produce fermented and dried matter 20, and a pyrolysis process (step S130) in which the fermented and dried light matter 22 selected from the fermented and dried matter 20, i.e., the fermented and dried light matter 22 which is a part of the fermented and dried matter 20, is heated to produce pyrolysis oil 220.

According to the waste treatment method of the above embodiment, in the fermentation and drying step (step S10), the waste 1 is aerobically fermented and dried to produce the fermented and dried matter 20, and in the pyrolysis step (step S130), the fermented and dried light matter 22 selected from the fermented and dried matter 20 is heated at a predetermined temperature to produce pyrolysis oil 220. The pyrolysis oil 220 thus produced contains heavy oil and light oil, and is easy to use as fuel or industrial raw material, and is expected to be in high demand. That is, the pyrolysis oil 220 produced by oiling the hydrocarbon content of the fermented and dried light matter 22 has a density of 0.7 to 0.9, which is equivalent to heavy and light oil, and is denser than the density of the solid fuel RDF produced from the fermented and dried matter 20, and is liquid, so that combustion control is easy and it is easy to use, and it does not take up much storage space and is not costly to store.
Thus, according to the waste treatment method of the above embodiment, pyrolysis oil 220 is produced which is highly versatile and has a wide range of uses, and which is expected to be consumed and in high demand in the vicinity of the waste plant, and waste 1 is recycled into pyrolysis oil 220 which is easy to use and is expected to have high demand.

In addition, in the waste treatment method of the above embodiment, the residue remaining after the pyrolysis oil 220 is separated from the fermented, dried, light material 22 in the pyrolysis process (step S130) is used as a solid fuel (RDF) raw material 210, which allows for the diversification of recycled waste materials (chemically recycled products, thermally recycled products) and allows for multiple uses.

The waste treatment method of the above embodiment further includes a desalting step in which the fermented, dried, light material 22 is desalted prior to the pyrolysis step, thereby reducing the residual chlorine in the pyrolysis oil produced from the desalted fermented, dried, light material 22. This allows for the production of higher quality pyrolysis oil (produced oil). In addition, the residue produced by pyrolysis of the hydrocarbon content of the desalted fermented, dried, light material 22 also has a low chlorine concentration, allowing the production of solid fuel RDF211 with a low chlorine concentration.

Furthermore, according to the waste treatment method of the above embodiment, in the fermentation and drying process (step S10), the fermented and dried fine granules 23, which are part of the fermented and dried product 20, are desalted and then mixed with the waste 1 as the fermentation auxiliary 3, and the waste 1 is efficiently fermented aerobically and dried to produce the fermented and dried product 20 with a low salt concentration. This reduces the residual chlorine concentration of the pyrolysis oil obtained by pyrolyzing the hydrocarbon content of the fermented and dried product 20, and the chlorine concentration of the residue obtained by pyrolyzing the hydrocarbon content of the fermented and dried light material 22, making it possible to provide a higher quality recycled product.

The above embodiment can also be considered as an invention of a waste treatment plant that includes a fermentation and drying processing section that aerobically ferments waste 1 and dries it to produce fermented and dried matter 20, and pyrolysis devices 111A, 111B, and 111C that heat the fermented and dried light matter 22 selected from the fermented and dried matter 20 to produce pyrolysis oil 220.

According to the waste treatment plant of the above embodiment, the waste 1 is aerobically fermented and dried in the fermentation and drying processing section to produce the fermented and dried matter 20, and the fermented and dried light matter 22 selected from the fermented and dried matter 20 is heated at a predetermined temperature in the pyrolysis devices 111A, 111B, and 111C to produce the pyrolysis oil 220. The pyrolysis oil 220 thus produced contains heavy oil and light oil, and is easy to use as fuel or industrial raw material, and is expected to be in high demand. That is, the pyrolysis oil 220 produced by oiling the hydrocarbon content of the fermented and dried light matter 22 has a density of 0.7 to 0.9, which is equivalent to heavy and light oil, and is denser than the density of the solid fuel RDF produced from the fermented and dried matter 20, and is liquid, so that combustion control is easy and it is easy to use, and it does not take up much storage space and is not costly to store.
Thus, according to the waste treatment plant of the above embodiment, pyrolysis oil 220 is produced which is highly versatile and has a wide range of uses, and which is expected to be consumed and in high demand in the vicinity of the waste treatment plant, and waste 1 is recycled into pyrolysis oil 220 which is easy to use and is expected to have high demand.

In addition, in the waste treatment plant of the above embodiment, the residue remaining after the pyrolysis oil 220 is separated from the fermented and dried light material 22 is used as a raw material for solid fuel (RDF) 211, so that recycled waste materials can be diversified and deployed for multiple uses.

The waste treatment plant of the above embodiment further includes a heating means for heating to a predetermined temperature and a water washing means as a desalting means for desalting the fermented, dried, light material 22 before pyrolysis of the fermented, dried, light material 22, so that the residual chlorine in the pyrolysis oil generated from the desalted fermented, dried material is reduced. Therefore, a higher quality pyrolysis oil (reproduced oil) can be generated.

Furthermore, according to the waste treatment plant of the above embodiment, in the fermentation and drying treatment section, the fermentation and drying fine granules 23, which are part of the fermentation and drying material 20, are desalted and then mixed with the waste 1 as the fermentation auxiliary 3, and the waste 1 is efficiently fermented aerobically and dried to produce the fermentation and drying material 20 with a low salt concentration. This reduces the residual chlorine concentration of the pyrolysis oil obtained by pyrolyzing the hydrocarbon content of the fermentation and drying material 20, and the chlorine concentration of the residue obtained by pyrolyzing the hydrocarbon content of the fermentation and drying light material 22, making it possible to provide a higher quality recycled material.

In the above embodiment, the fermented and dried fine granules 23 selected from the fermented and dried material 20 are used as the fermentation auxiliary material 3. However, when implementing the present invention, a portion of the fermented and dried fine granules 23 may be used as the compost raw material 230. The compost raw material 230 is matured for several days to several weeks in a separate maturation bed while being watered and aerated, as in the aerobic fermentation and drying described above. It can then be sieved according to the intended use and conditions of use, and further matured if necessary, to produce a high-quality compost. This allows the recycled material to be used in a wider variety of applications.

In the above aerobic fermentation, the explanation has been given on the assumption that aerobic microorganisms are used. However, this does not mean that there is no adhesion of anaerobic microorganisms, but rather that an environment in which aerobic microorganisms can work is created.
In addition, when implementing the present invention, the configuration, ingredients, blending, manufacturing method, etc. of other parts of the waste treatment plant and waste treatment method are not limited to those in the above examples. Furthermore, the numerical values given in the embodiments and examples of the present invention do not all indicate critical values, and some numerical values indicate suitable values for implementation, so even if the numerical values are slightly changed within the allowable values, it does not negate the implementation.

1 Waste 20 Fermented and dried material 22 Fermented and dried light material 111A, 111B, 111C Pyrolysis device 210 Solid fuel raw material 211 Solid fuel (RDF)
220 Pyrolysis oil (produced oil)

Claims (6)

a fermentation and drying process in which the waste is aerobically fermented and dried to obtain a fermented and dried product;
a pyrolysis step of heating the fermented and dried product to produce pyrolysis oil. The waste treatment method according to claim 1, characterized in that the residue obtained by separating the pyrolysis oil from the fermentation and drying product in the pyrolysis process is used as a raw material for solid fuel (RDF). The waste treatment method according to claim 1, further comprising a desalination step for desalination of the fermented and dried product prior to the pyrolysis step. a fermentation and drying treatment section for aerobically fermenting the waste and drying it to produce a fermented and dried product;
and a pyrolysis device for heating the fermented and dried product to produce pyrolysis oil. The waste treatment plant according to claim 4, characterized in that the residue obtained by separating the pyrolysis oil from the fermentation and drying product is used as a raw material for solid fuel (RDF). The waste treatment plant according to claim 4, further comprising a desalting means for desalting the fermented and dried material before pyrolysis of the fermented and dried material.

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