Method and apparatus for waste processing of mixed waste

Abstract

providing a heating environment for heating the inorganic waste portion to a temperature higher than in the composting unit, and a control unit for controlling a moisture level of the mixed waste load in the heating unit

Description

[Technical Field]

[0001] This invention relates to a method and apparatus for the treatment of mixed waste, which comprises compostable organic waste and non-compostable organic waste, particularly for the treatment of household waste. In particular, the method and apparatus of this invention relate to the treatment of mixed waste without the need for pre-sorting or segregation of the solid waste portion prior to waste treatment. [Previous Technology]

[0002] More than 2 billion metric tons of mixed waste, also known as solid waste or general waste, are generated worldwide each year. Currently, only 13.5% of solid waste is recycled. As a long-standing recipient of recycled plastics, China has announced that most of the plastics it receives are too dirty, leading it to stop importing such recyclable goods. The ineffectiveness of recycling is further exacerbated by slow behavioral changes, where the main reason people avoid separating waste for recycling is inconvenience. Every day, densely populated areas like Singapore process large amounts of general waste, consisting of unseparated compostable organic waste such as food waste and non-compostable organic and inorganic waste such as plastics, glass, and metals. The latter part of mixed waste is typically recyclable. Paper can be considered mixed waste because a small portion of paper present in compostable waste is compostable. However, a large amount of paper should and typically is recyclable.

[0003] For example, Singapore's current general waste disposal method relies on large compactors that can hold the waste until it is transported to an incineration plant. However, there is no on-site processing option for general waste, so compactors typically reach full capacity within a few days. Singapore also requires the immediate processing of compostable organic waste to prevent pest infestations; this means on-site processing or removal is necessary. However, on-site processing of compostable / food waste has historically been difficult due to a lack of waste segregation. Furthermore, the continuous back-and-forth movement of garbage trucks generates significant amounts of greenhouse gases. This waste disposal method is costly, inefficient, and dangerous for our planet and its inhabitants.

[0004] Singapore is just the tip of the iceberg. Many countries that generate far more waste lack the facilities to incinerate their waste. In 2019, Singapore announced that its Pulau Semakau landfill would be fully operational by 2035. Soon, many other landfills around the world will be unable to accept any more waste.

[0005] Furthermore, general waste is frequently contaminated by food waste, and vice versa. This is mainly due to the lack of segregation measures at the source of waste generation. Recyclable waste such as paper becomes difficult to recycle once contaminated by pollutants such as food or oil. Similarly, food waste is often mixed with general municipal waste such as plastic straws and plastic packaging. This makes food waste recycling challenging due to the nature of food waste recycling machines. To prevent these scenarios, segregation at the source will have the greatest impact. However, this will require disciplinary, social, and cultural changes, which are very difficult.

[0006] Traditional food waste collection methods involve manually separating food waste from general or mixed waste so that the separated food waste can be further processed in a food waste digester or composter without any contaminants. This labor-intensive separation process often leads to undesirable results for the digester or composter, making it unable to effectively process the contaminated food waste. Not only does this system typically end up with 20 wt.%-40 wt.% of undecomposed impurities, but it also tends to malfunction due to excessive impurities, or the composter may end up with a large amount of impurities in the compost.

[0007] Numerous large-scale waste treatment plants are known to process general waste, compost, or other waste materials. For example, CN 101215490 describes a management system based on a large-scale plant, which, depending on the addition of coal and chemicals, ensures that the resulting products are combustible. AU 2001097046 describes a waste processor that includes a shredder that shreds each piece of waste into fine granular material. US 4,203,376 discloses a waste treatment system specifically for processing food waste in a large-scale plant manner. Food waste is burned to obtain an energy source. However, these waste treatment plants do not mitigate the aforementioned disadvantages.

[0008] The purpose of this invention is to provide a method and apparatus for the treatment of mixed waste, which has a simple and compact setup, provides efficient waste treatment, provides an environmentally beneficial process and useful output, reduces greenhouse gas emissions, and is cost-effective. [Summary of the Invention]

[0009] According to Independent Claims 1 and 12, these and other objectives are achieved by a method for treating mixed waste comprising compostable organic waste portions and non-compostable organic waste portions, and by an apparatus for treating mixed waste. Furthermore, a system for treating mixed waste is provided. Advantageous features and preferred embodiments of the invention are disclosed in the appended claims.

[0010] Herein, the term "mixed waste" should be understood as waste generated by humans in private households, or waste accumulated in offices, shopping malls, commercial complexes, or businesses, or such as animal feed for consumption, daily necessities, and other leftovers from human or animal life. The terms general waste and solid waste are used synonymously. As currently understood, liquid waste such as excrement and bath / shower residue is not considered part of mixed waste. This also applies to bulky waste such as furniture, scrap wood, electronic waste, old clothes, construction waste, or larger quantities of garden and horticultural waste. Industrial waste originating from manufacturing processes is not considered mixed waste. Defective waste such as batteries should also not be considered part of mixed waste accumulated in households.

[0011] Mixed waste can be considered to comprise two main parts: compostable organic waste and non-compostable organic waste. Food waste is sometimes used as another term for the compostable organic portion of general waste. However, paper itself is also compostable. Therefore, a small amount of paper in mixed waste will also be considered part of the compostable waste. Although the non-compostable organic waste portion is sometimes designated as the inorganic waste portion, the preferred terminology currently uses chemical identification. From a chemist's point of view, plastic is an organic component, and "non-compostable organic waste portion" seems more accurate. The non-compostable organic waste portion is distinct from the non-compostable inorganic portion of mixed waste, such as glass or metal.

[0012] The waste treatment method of the present invention for mixed or solid waste treats mixed waste comprising compostable organic waste portions and non-compostable organic waste portions. This waste treatment method is particularly suitable for treating household waste. For example, mixed waste may originate from packaging, disposable tableware and utensils, consumer goods, food preparation or production, and food scraps. Food waste portions may include, for example, meat, bones, vegetables, fruit seeds (from durian, apple, orange, avocado, etc.), fruit and vegetable peels and shells (such as coconut shells), sugarcane, and garden waste. Generally, food waste portions represent organic and compostable waste portions. Organic but non-compostable waste portions may include, for example, plastic bags, plastic products, packaging, wet wipes, foamed plastic boxes, etc. Therefore, mixed waste can be contaminated or uncontaminated general waste, which typically accumulates in households, offices, restaurants, small businesses, etc.

[0013] According to the waste treatment method, one load of mixed waste is fed into a shredder and shredded into fragments smaller than the initial size. Loading can be done manually, machine-assisted, or fully automated. The shredded solid waste is conveyed into a composting unit, such as a compost bin. Optionally, a series of composting units or compost bins can be provided, wherein the load of this solid waste continuously passes through the composting unit. Two parts—a food waste portion and a non-compostable waste portion—enter and pass through this composting unit or multiple composting units simultaneously. The food waste portion of the mixed waste load is composted in the microbial environment of the composting unit. Then, the intermediate product consisting of the mixed waste load processed in the composting unit is conveyed from the composting unit into a heating unit, such as a heating bin. That is to say, the compostable food waste portion and the non-compostable waste portion enter the heating unit. In a heated bin, the waste load being processed in the compost bin is heated to a higher temperature than in the composting unit to dry the processed waste to a target humidity level below the initial humidity level. Finally, the total volume and mass of the mixed waste load processed according to the invention are significantly reduced. Upon reaching the target humidity level, the product is transported to the outlet unit. After waste processing, the product, i.e., the processed mixed waste load, consists of a portion of food waste that has been crushed, composted, and dried, and a portion of non-compostable organic waste that has been crushed and dried; these can be easily separated for further use, such as recycling or incineration.

[0014] The waste treatment method according to the present invention can be carried out, for example, by a waste treatment device for mixed waste according to the present invention. This waste treatment device is constructed for treating mixed waste comprising a compostable portion of organic waste as described above and a non-compostable portion of organic waste. The waste treatment device includes a crusher unit for crushing a load of solid waste; a composting unit, such as a composting bin, providing a microbial environment for composting the compostable portion of the solid waste load; a heating bin providing a heating environment for heating the waste from the composting unit to a temperature higher than that in the composting unit; at least one control unit for controlling the humidity level of the solid waste load in the heating unit and / or the composting unit; and at least one means for conveying intermediate products of the mixed waste from the composting unit to the heating unit; such as a conveyor means for transporting waste processed in the composting unit to the heating unit. Furthermore, another means may be provided for conveying solid waste from the crusher unit to the composting unit and / or from the heating unit to the outlet unit. Examples of such means are conveyor systems such as conveyor belts or screw conveyors.

[0015] The method and apparatus for solid waste treatment according to the present invention provide an advanced biotechnological solution to alleviate waste handling without the need for isolation. This is a significant advantage over conventional waste treatment because the compostable portion is composted and can be separated from the non-compostable portion, thus greatly reducing the volume and mass of residual waste requiring incineration, further recycling, or landfill. Furthermore, mixed waste can be treated on-site, such as in apartment buildings. More than one apparatus according to the present invention can be installed in a block of buildings so that waste accumulated in the block of buildings can be treated on-site. This on-site plant can be filled periodically. It takes approximately 24 hours from loading the product to the exit of a channel. Therefore, the apparatus can be filled daily with mixed waste collected from apartments within the block of buildings. Its compostable portion will not smell and pests or pathogens are also periodically eliminated. The non-compostable portion can be advantageously used as waste-derived fuel (RDF), as will be explained further below. Thus, the goal of zero waste can be achieved.

[0016] As briefly explained above, the advantages of the solid waste treatment method and apparatus according to the present invention are that, unlike large-scale industrial plants known in the prior art, this method and apparatus can and is intended to operate on a smaller scale, suitable for space-constrained locations, such as garbage centers in residential areas, shopping malls, or commercial complexes. Furthermore, most prior art systems cannot simultaneously grind and process different forms and sizes of waste. The method and apparatus of the present invention includes a shredder capable of simultaneously shredding, flattening, and grinding plastic packaging, paper, foamed plastic boxes, coconut shells, meat, etc. Although the waste in this system does not need to be ground to a uniform size, this system can process all forms of waste and reduce them to, for example, RDF and compost. Currently, a large amount of greenhouse gas emissions are from the frequent transport of food and general waste to incinerators. To alleviate this problem, the mixed waste treatment method and apparatus according to the present invention reduce the volume of waste (e.g., 10 tons of mixed waste can be reduced to 2 tons). Solid waste treatment reduces the frequency of waste transport, especially food waste (which spoils quickly). Therefore, fewer greenhouse gases are emitted through the transportation of these waste materials.

[0017] In a preferred embodiment of the waste treatment method according to the present invention, the target humidity level is at least 50 wt.% lower than the initial humidity level. Target humidity levels of 30-40 wt.% for the compost portion and a maximum of 15 wt.% for the RDF portion have been found to be feasible. The waste treatment equipment may include a humidity sensor in a heated bin, and preferably also includes a humidity sensor in a compost bin. The humidity sensor can provide the humidity level to at least one control unit, which determines whether the target humidity level has been reached. In this case, the treated solid waste load will be further transported to the next treatment step by a conveyor unit.

[0018] In an embodiment of the waste treatment method according to the invention, the temperature in the composting unit is below 70°C but above 30°C, preferably above 50°C. It has been noted that a temperature of approximately 60°C in the composting unit appears to be most advantageous. It is clear to any expert that the temperature will depend on the microorganisms present or added for the degradation of compostable waste portions, as composting is a temperature-sensitive process. Therefore, experts will select a temperature or temperature range favorable to the microbial environment, resulting in rapid composting and decomposition of the food waste portions. Advantageously, in the compost bin, organic waste will be decomposed through a microbial process in a microbial environment at 60°C and become compost.

[0019] The microbial environment reduces the initial volume of solid waste load to below 70 vol%, for example, within approximately 24 hours or longer. The microbial environment comprises, for example, microorganisms or combinations of microorganisms that partially degrade compostable waste to below 25 vol%, preferably 15-20 vol%, of its initial volume within 24 hours. Although the microorganisms used in the compost bin cannot digest non-compostable organic materials such as plastics, the volume of the waste gradually decreases as heat is applied to process the solid waste load. Thus, for example, the volume of compostable waste is reduced to 15-20 vol%, while the volume of non-compostable waste such as plastics and paper is reduced to 50-70 vol%. Similarly, the mass of mixed waste is reduced due to the removal of water.

[0020] Microorganisms can decompose food waste and remove any putrid odors often emitted by rotting food. Instead, the decomposition process releases only CO2. The process and equipment do not emit any foul odors during the decomposition process.

[0021] In a further embodiment of the waste treatment method according to the present invention, the temperature in the heating tank is below 1100°C, particularly in the range of 80°C to 100°C. Therefore, in the heating tank, the food waste portion and the non-compostable waste portion are heat-treated at approximately 90°C to reduce moisture content. Preferably, the maximum temperature is controlled at 110°C, more preferably at 100°C. This is to prevent the plastic from melting on-site and releasing toxic fumes. During the heating step, the non-compostable portion of the waste, especially the plastic, becomes smaller, more compact, and more brittle. Therefore, its original size is significantly reduced, resulting in a significant reduction in the volume of waste treated according to the present invention compared to untreated waste of the same composition.

[0022] The waste treatment equipment preferably includes a temperature sensor that measures the temperature in the composting unit and the heating unit. If the temperature in the compost bin exceeds 60°C and the temperature in the heating bin exceeds 100°C, the built-in temperature sensor will send an alarm to the control unit, and the automation software will adjust the temperature accordingly.

[0023] In a further example of the waste treatment method and apparatus according to the invention, a weighing unit measures the mass (in kilograms) of the solid waste load to be loaded into the shredder. For example, a mixed waste load is provided in a common household garbage bin and loaded onto the force gauge of the weighing unit before the solid waste load enters the compost bin. The mass of the mixed waste load is reported to the control unit to control the amount of mixed solids entering the waste treatment apparatus. Weighing is useful because, preferably, further mixed waste loads can enter the apparatus while the first solid waste load is still being processed in the bin. In the preferred embodiment, an apparatus can process a total volume of solid waste of about 1-100 tons (1,000-100,000 kg). Depending on the location where the apparatus is erected, the apparatus is designed to handle loads smaller or larger than previously possible. A control unit prevents loads larger than the apparatus is designed to enter the apparatus. For example, a larger load can be broken down into smaller loads that can be processed subsequently.

[0024] In another alternative embodiment of the waste treatment method and apparatus according to the present invention, a condensation system is disposed at the heating tank and preferably also at the composting tank. This system is designed to collect condensate from the heating unit and preferably also from the composting unit. The condensation system reduces moisture in both tanks. This is achieved by reducing moisture in the system, promoting the drying of compostable and non-compostable waste portions in the tanks, especially the heating tank, which in turn reduces the mass of the treated solid waste load. The condensation system collects clean water that can be removed from the equipment for further use.

[0025] Another embodiment provides that thermal energy can be reused by guiding hot air from each barrel back to itself.

[0026] It is further proposed that hot air from the two barrels be directed to the heating unit to maintain a higher temperature of 90°C.

[0027] In another variation of the waste treatment method according to the present invention, the load of crushed, composted, and dried solid waste arriving at the outlet unit is separated into a compostable portion and a non-compostable portion. This separation can be performed at the outlet unit. Alternatively, this separation can be performed at a centralized facility comprising a separating unit designed to separate the load of crushed, composted, and dried solid waste into a compostable portion and a non-compostable portion, and a pelletizing unit designed to pelletize the non-compostable portion into waste-derived fuel. For example, the separating unit includes a vibrating screening device to separate the compostable portion and the non-compostable portion.

[0028] Advantageously, the non-compostable portion can be pelleted and used as waste-derived fuel for future use, such as incineration.

[0029] The waste treatment method and apparatus according to the present invention allow solid waste to be reused as RDF and compost, instead of being dumped in landfills or incinerated entirely. Furthermore, the need for recycling and sorting before waste treatment is significantly reduced. The resulting compost can be used in agriculture, and the RDF can be used as fuel.

[0030] In yet another embodiment of the waste treatment method according to the present invention, before loading solid waste into the shredder, non-compostable inorganic waste, such as metal waste and / or glass waste, is extracted from the mixed waste. These waste materials are valuable resources that can be reused and recycled.

[0031] In one embodiment of the waste treatment apparatus according to the present invention, at least one control unit is configured to control the mass of solid waste loading, the temperature in the compost bin, the temperature in the heating bin, and / or the moisture in the heating bin. The control unit may be a computer. The control unit may be integrated into the device, or it may be externally connected to the device, for example, via an electronic network system. The control unit may include software for automatically tracking the application chamber of the waste treatment method according to the present invention.

[0032] The waste treatment equipment according to the present invention uses a small, compact and decentralized setup to reduce the tonnage of waste at the source and separate it from centralized large-scale plant systems used for waste treatment.

[0033] In a preferred embodiment, the device according to the invention is small-scale and is installed and used decentralizedly at or near the location where mixed waste to be treated is generated, such as in apartment buildings, residential areas, office buildings, and / or shelters. Compared to large-scale devices, the invention can be used on-site when waste is generated, which is a feature of reducing transportation and thus reducing CO2 emissions. After the mixed waste is reduced in mass and volume by passing through the machine of the invention, the transportation capacity and frequency required are reduced compared to transporting waste that has not been treated by the invention to central facilities such as landfills, waste collection stations, or waste incineration plants.

[0034] As understood herein, the term “small scale” means that the equipment has dimensions between 50% and 300% of the maximum width of 4 meters, the maximum height of 5 meters, and the maximum length of 12 meters. A typical Singapore silo center requires a roller switch opening of 4 meters (net width) to 5 meters (net height), and this requirement applies to silo centers accommodating roll-on / roll-off waste compactors / containers and other waste storage systems requiring transport. If the silo center is located within a building envelope or has a roof or shelter in front, there should be sufficient clearance of at least 4 meters (net width) x 5 meters (net height) for transporting roll-on / roll-off waste compactors / containers.

[0035] The accompanying drawings depict one preferred embodiment of the structure for the apparatus, in which compost bins and heating bins are arranged one after another. A screw conveyor is installed as a means for conveying pre-treated waste from the composting unit to the heating unit.

[0036] In an alternative series configuration, the composting unit and the heating unit are stacked one on top of the other, preferably with the composting unit stacked on top of the heating unit. A single housing can be provided. The advantage of this stacked configuration is that the device can be built upwards if space is limited in a given location. This is particularly true in larger cities where land is expensive. The mass processed in the composting unit, after passing through the crushing unit, should be transferred to the heating unit below the composting unit. If these bins are stacked together, the doors between them can be configured to open, allowing the mass from the composting unit to be pushed through to the heating unit. Alternatively, an internal conveyor belt can be provided to transport this mass from the first bin to the second bin. Subsequently, other elements of the device according to the invention may need to be designed to suit this modified structure; for example, the crushing unit may need to be positioned in front of the stack of composting and heating units, rather than on top of the composting unit, as is the case in the embodiment shown in the figures.

[0037] The system of the present invention for the treatment of mixed waste comprising compostable organic waste and non-compostable organic waste comprises at least two, preferably more than ten, inventive devices for waste treatment, including a separating unit for separating the products into compostable and non-compostable portions and a pelletizing plant for pelletizing the non-compostable portion into RDF. In a preferred embodiment, such devices are installed in numerous locations, for example throughout a city, each generating enough mixed waste to economically operate the device. All products generated by all devices are transported to a centralized location where compost is separated from the remaining portions and can be sold. The remaining portions, i.e., the non-compostable portions, can be recycled if the plastic portion is sufficiently clean. However, it will typically be used as RDF. For this purpose, it will be pelletized and these pellets can be sold. Thus, instead of incurring high costs for landfilling or disposing of waste, waste is transformed into a useful product that can be sold and generate revenue. It should be noted that another advantage is the reduction of CO2 emissions from transportation, because less transport capacity will be required given the reduced mass and volume of the product compared to the amount of mixed waste loaded.

[0038] In summary, the waste treatment method and apparatus according to the present invention do not require any waste segregation. The present invention is readily available from home and can transform general waste, also known as solid waste or mixed waste, into manageable and useful products. This method and apparatus can effectively convert both contaminated and uncontaminated solid waste, and compostable organic waste, into waste-derived fuel (RDF), a new energy form that can be developed for industrial and household use. This waste treatment method and apparatus revolutionize current waste management practices, which are labor-, cost-, and space-intensive, not to mention the significant pollution they generate. They help reduce the burden on landfills and are steps toward zero waste and sustainable ecosystems.

[0039] The waste treatment method and apparatus according to the present invention offer several advantages. Food waste and general waste can be treated into organic compost and useful energy, respectively. Automated aeration and temperature control allow for further processing of organic compost and contaminated waste into RDF. While processing an ongoing load of solid waste, the next load can be added simultaneously, allowing the apparatus to operate 24 hours a day. At the end of the process, organic compost and RDF can be isolated within the apparatus during transport, making it a compact system without compromising the extraction of these useful resources. Metals and non-metals (including batteries) contained in general waste can be sorted, extracted, and redirected for separate treatment and / or recycling.

Implementation Method

[0044] These figures illustrate a preferred embodiment of an apparatus for waste treatment 50. This apparatus can treat mixed waste, hereinafter also specified as including a portion of compostable organic waste, a portion of food waste, and a portion of organic but non-compostable solid waste. This waste treatment apparatus 50 includes an input unit 1, a crusher unit 2, a composting unit 3, a heating unit 4, at least one control unit (not shown), a conveyor 5, and an outlet unit 6.

[0045] Input unit 1 includes a vertical lifting tower 7 and a carrier 8, which is designed to move up and down the lifting tower 7. The carrier 8 can transport the solid waste load upwards to the input opening 10 of the shredder unit 2. For example, the solid waste load can be provided in a garbage bin 9, which can be attached to the carrier 8 when the carrier is in a lower position and moves upwards on the carrier 8 with the lifting tower 7. In the upper position, the carrier 8 moves the garbage bin 9 toward the input opening 10 and causes the garbage bin 9 to invert, causing the solid waste load to fall into the input opening due to gravity. The empty garbage bin 9 can be flipped back and moved downwards along the lifting tower 7. Then, the garbage bin 9 is ready to receive further waste.

[0046] A weighing unit 11 containing a force measuring device is provided as part of the shredder unit 2. Alternatively, it may be provided separately as part of the lifting tower 7 before the shredder unit or before the garbage bin 9 is inserted into the lifting tower. The weighing unit 11 measures the mass of the mixed waste load to be processed and provides mass data (not shown) to the control unit.

[0047] After entering the shredder unit 2, the waste load is shredded. The shredder unit 2 shreds the mixed waste load into smaller fragments, which fall into the composting unit 3 located below the shredder unit 2.

[0048] In a preferred embodiment, the composting unit 3 is a barrel. This barrel is rotated continuously or intermittently by a motor 15, and thus mixed with the materials contained therein. This is advantageous, wherein the waste is mixed with composting microorganisms and is simultaneously aerated.

[0049] In composting unit 3, the pulverized mixed waste particles are exposed to a microbial environment and a suitable temperature, such as 60°C, for composting the compostable portion of the solid waste load. The non-compostable waste portion is also present in composting unit 3. Therefore, composting of the compostable waste portion occurs regardless of the presence or percentage of non-compostable waste. Although the non-compostable organic waste portion cannot be decomposed by microorganisms, its mass and volume decrease due to evaporation caused by the temperature in composting unit 3.

[0050] Next, the intermediate product consisting of the compostable proportion of the mixed waste loaded in the composting unit is conveyed to the heating unit 4 via the conveyor unit 5. The conveyor unit 5 may be, for example, a shaftless screw conveyor, which is connected at its bottom to the outlet of the composting unit 3 and at the input of the heating unit 4 in the upper region of the heating unit 4. The crushed and composted intermediate product is transported to the input of the heating unit 4, released into the heating unit 4, and falls downward by gravity.

[0051] The heating unit 4 is preferably a barrel actuated by a motor 16. Similar to compost bins, a rotary heating unit is advantageous for mixing and distributing the pre-treated waste present in the heating unit. Rotation can be continuous or intermittent. Typically, a low rotational speed is sufficient – ​​this is also true for compost bins.

[0052] Heating unit 4 provides a heating environment for heating waste to a higher temperature than that in the compost bin. In the preferred embodiment, the temperature in heating unit 4 is approximately 100°C, but not much higher, to avoid generating volatile harmful gases.

[0053] The considerably high temperature further raises the temperature of the pre-treated waste. This causes the plastic materials contained therein to shrink, thus reducing the volume of the plastic waste. Any pathogens that may not have been killed in composting unit 3 will be killed by the heat treatment in heating unit 4.

[0054] A humidity sensor (not shown) is disposed in the heating unit 4 to detect the humidity therein. The humidity sensor provides humidity data to the control unit.

[0055] The humidity sensor may also be part of the composting unit 3.

[0056] Furthermore, in a preferred embodiment not depicted in the figures, a condensation system is installed in both the composting unit 3 and the heating unit 4. This condensation system collects condensate evaporated from the load of mixed waste processed in both units. The condensation system may include a condensation sensor to collect information about the amount of condensate drawn from the tank. The condensation sensor provides the condensate data to a control unit, which can take the condensation into account when determining a target humidity level.

[0057] A target moisture level for the product is predetermined and provided to the control unit. The target moisture level is determined such that both the compostable and non-compostable waste portions are very dry, resulting in a significant reduction in the mass and volume of the product. In a preferred embodiment, the target moisture content of the waste for composting is 40 wt.%, or even more preferably 30 wt.%, and the target moisture content of the non-compostable waste is 15 wt.% or less. Upon reaching the target moisture content, the dried product can be extracted from the equipment 50. For example, the dried waste product is transported from the heating unit 4 to the outlet unit 6, such as an outlet or any other discharge unit.

[0058] The products leaving this waste treatment facility 50 include compostable and non-compostable waste. Compared with the mixed waste load entering the waste treatment facility 50, the moisture content of the products and therefore their mass and volume are greatly reduced.

[0059] The product can be isolated on-site or transported to a centralized facility with a separation unit designed to separate the mixed waste load after crushing, composting and drying, i.e., the product into compostable and non-compostable portions; and a granulation unit designed to granulate the non-compostable portion into waste-derived fuel.

[0060] In a preferred embodiment, the control unit is configured to control the mass of the solid waste loading, the temperature in the composting unit 3 or several composting units 3, the temperature in the heating unit 4, the removal of condensate in the heating unit 4, and moisture. Taking into account data provided by various sensors, such as those present in the composting unit 3, heating unit 4, conveyor 5, and / or outlet unit 6, the control unit further actuates the further input of the next solid waste loading and the extraction of the product. It controls the temperature in the composting unit 3 to be suitable for a microbial environment and controls the temperature in the heating unit 4 to be suitable for reaching a target humidity level without melting but still reducing the plastic waste content.

[0061] The microbial environment can be established by any type of microorganism suitable for decomposing organic materials. It can be a single type of microorganism or a mixture of microorganisms. Specific microorganisms can be used depending on the typical composition of the compostable waste portion of the solid waste load. Generally, decomposition is carried out by heterotrophic microbial communities and microfauna including, for example, bacteria, fungi, actinomycetes, and protozoa.

[0062] In an example of the waste disposal method according to the present invention, the operator pushes the garbage bin 9, which contains the solid waste load on the carrier 8 in the lifting tower 7, and closes the safety door. The operator presses the "Dump" button, which initiates the carrier 8 to move upward and dump the solid waste load onto the weighing unit 11, which in this embodiment is located in front of the crusher unit 2. The weighing unit 11 measures the solid waste load and records the tonnage into the control unit. The hatch holding the solid waste load on the weighing unit 11 is opened, and the solid waste load falls into the crusher unit 2, which is started manually or by the control unit. All waste, including compostable and non-compostable waste, is crushed and pulverized into smaller pieces and falls into the composting unit 3. In composting unit 3, organic waste is decomposed by microbial activity at approximately 60°C, transforming it into compost and reducing organic waste by 15 wt.% to 20 wt.%. Residual waste, such as plastics and paper, is reduced by 50 wt.% to 70 wt.%. It should be noted that paper can be decomposed by microorganisms, depending on the number of microorganisms and the amount of paper. Paper itself is compostable. After approximately 24 hours or longer, the control unit activates the conveyor unit to transport the intermediate products generated by composting unit 3 to heating unit 4 via shaftless screw conveyor unit 5. In heating unit 4, which is also a designated processing bin, the compost and the non-compostable waste portion, which has reduced volume and mass, undergo heat treatment at approximately 90°C to reduce moisture content and shrink plastic pellets. Once the humidity sensor detects that the humidity level in heating unit 4 has reached the target level, the program will initiate the transfer of the final product, the composted food waste portion, and the dried residual waste portion, for example, through outlet unit 6 into a collection bin. This waste can then be transferred to a centralized facility where a vibrating screening device separates the composted waste portion from the non-composted waste portion. At the end of this process, there is an option to granulate the dried inorganic waste portion into RDF granules, which can be sold for incineration.

[0063] The waste treatment method and apparatus according to the present invention include a treatment flow for treating large quantities of solid waste (including organic / food and non-compostable general waste) without any pre-sorting, but simply by pouring the load of solid waste into the apparatus of the present invention.

[0064] Using proprietary grinding or pulverizing technology, all types of waste, including contaminated and uncontaminated solid waste (as defined), are ground into small pieces. This waste is then transported / transported between various bins within the equipment. Optionally or if desired, it may be possible to provide preliminary sorting of the various types of waste, particularly the sorting of metals and non-metals (including batteries). Reusable metals can then be extracted and redirected for separate processing and / or recycling. Similarly, non-metals (including batteries) are redirected for separate processing and / or recycling.

[0065] As described above, the shredded solid waste is then processed in multiple units, typically bins. There may be more than one compost bin, each providing a different microbial environment, with a specific microbial mix to process different types of waste. By combining specific microbial mixtures with their respective optimal temperature ranges and holding the combined waste for a predetermined time, the microbial mixtures can degrade many components of the waste.

[0066] The advantages of the method and apparatus according to the present invention are: • Organic and inorganic wastes can be processed together without any separation. • Compostable and non-compostable wastes can be rapidly converted into compost and RDF within a processing cycle of approximately 24 hours. • Environmentally friendly treatment without irritating odors or secondary pollution. • It can be customized to a given space. • User-friendly with a simple programmable logic controller (PLC) system. • Highly automated and efficient processing. • Reduced carbon footprint by reducing transportation frequency. • Promotes environmental sustainability and moves towards a zero-waste nation. [Simplified Explanation of the Diagram]

[0040] Exemplary embodiments of the present invention will be illustrated in the following drawings, which are for illustrative purposes only and should not be construed as limiting. Features of the invention that become apparent from the drawings should be considered part of the disclosure of the invention, either alone or in any combination thereof. These drawings show:

[0041] [Figure 1]: Perspective view of the waste treatment equipment according to the present invention;

[0042] [Figure 2]: Side view of the waste treatment equipment in Figure 1; and

[0043] [Figure 3]: Top view of the waste treatment equipment shown in Figures 1 and 2.

Claims

1. A method for the disposal of mixed waste, the mixed waste comprising compostable organic waste and non-compostable organic waste, the method comprising the following steps: crushing the load of the mixed waste in a crushing unit (2) to generate a crushed load of mixed waste; conveying the crushed load of mixed waste into a composting unit (3); composting the compostable organic waste in the microbial environment of the composting unit (3) to generate a mixed waste intermediate product; conveying the mixed waste intermediate product from the composting unit (3) into a heating unit (4); The mixed waste intermediate product is heated to a temperature higher than that of the composting unit (3) to dry the mixed waste intermediate product to a target humidity level lower than the initial humidity level, thereby producing a product containing compost and waste-derived fuel; and when the target humidity level is reached, the product is transported to the outlet unit (6), thereby reducing the moisture content, mass and volume of the product transported to the outlet compared to the load of the mixed waste.

2. The waste treatment method of claim 1, wherein the temperature in the composting unit (3) is below 70°C, preferably below 60°C.

3. The waste treatment method of claim 1 or 2, wherein the temperature in the heating unit (4) is below 110°C, especially in the range of 80°C to 100°C.

4. The waste treatment method as requested in item 1 or 2, wherein the mass of the mixed waste to be loaded into the shredder unit (2) is determined.

5. The waste treatment method of claim 1 or 2, wherein the microbial environment is established by adding microorganisms to the composting unit (3), wherein the microorganisms at least partially degrade the compostable organic waste portion of the mixed waste to be composted.

6. The method of claim 5, wherein the microorganisms partially degrade compostable organic waste to less than 25 vol.% of its initial volume within 24 hours.

7. The waste treatment method of claim 5, wherein the microorganisms reduce the initial volume of the mixed waste load to less than 70 vol.% of the initial volume.

8. The waste treatment method as claimed in claim 1 or 2, wherein condensate is extracted from the heating unit (4).

9. The waste treatment method of claim 1 or 2, wherein the product is separated into compost and waste-derived fuel.

10. The waste treatment method of claim 9, wherein the waste-derived fuel is formed into pellets.

11. The waste treatment method of claim 1 or 2, wherein the target humidity level is at least 50 wt.% lower than the initial humidity level.

12. An apparatus for the treatment of mixed waste comprising a compostable organic waste portion and a non-compostable organic waste portion, the apparatus comprising: a pulverizing unit (2) for pulverizing a load of the mixed waste, thereby generating a pulverized load of mixed waste; a composting unit (3) providing a microbial environment for composting the compostable organic waste portion of the pulverized load of mixed waste, thereby generating a mixed waste intermediate product; a heating unit (4) providing a heating environment for heating the mixed waste intermediate product to a temperature higher than that in the composting unit (3), thereby generating a product comprising compost and waste-derived fuel; at least one control unit for controlling the humidity level of the material processed in the composting unit (3) and / or the heating unit (4); an outlet unit (6) from which the product can be extracted; and at least one means for conveying the mixed waste intermediate product from the composting unit (3) to the heating unit (4), such as a conveyor means (5).

13. The equipment for waste treatment as claimed in claim 12, wherein a scale unit (11) is provided for determining the mass of the mixed waste load before it is loaded into the shredder unit (2).

14. The waste treatment equipment as claimed in claim 12 or 13, wherein the at least one control unit is configured to control the mass of the mixed waste load, the temperature in the composting unit (3) and / or the temperature in the heating unit (4).

15. The waste disposal apparatus of claim 12 or 13, wherein a condensation system is at least configured in the heating unit (4), which is designed to collect condensate from the heating unit (4).

16. The equipment for waste disposal as claimed in claim 12 or 13, wherein the composting unit (3) and the heating unit (4) are connected in series and arranged one after another.

17. The equipment for waste disposal as claimed in claim 12 or 13, wherein the composting unit (3) is stacked on top of the heating unit (4).

18. The waste disposal equipment as claimed in any of claims 12 or 13, which is small and designed for decentralized on-site installation and use at or near the location where mixed waste to be disposed of is generated, such as in apartment buildings, residential areas, office buildings and / or shelters.

19. A system for the treatment of mixed waste comprising a compostable organic waste portion and a non-compostable organic waste portion, the system comprising: at least two waste treatment devices as claimed in any one of claims 12 to 15; a facility including a separation unit designed for separating the product into the compostable and non-compostable portions; and a pelletizing plant for pelletizing the non-compostable portion into the waste-derived fuel.

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