A method and system for resource utilization of all components of kitchen waste based on thermal hydrolysis

Abstract

The invention discloses a method and system for resource utilization of all components of kitchen waste based on thermal hydrolysis, which sorts and crushes the kitchen waste, crushes and separates the water-insoluble solid impurities in the kitchen waste; recycles the separated plastic bags, and makes metal products for recycling after gravity separation; preheats the crushed and sorted kitchen waste and performs low-temperature thermal hydrolysis to separate grease; preheats the crushed and sorted kitchen waste and performs high-temperature thermal hydrolysis to separate bio-oil; configures the aqueous product separated by thermal hydrolysis into leaf fertilizer, and uses the solid residue as a soil conditioner. The invention improves the utilization rate of kitchen waste, reduces the pollution damage to the environment, and realizes the resource utilization of kitchen waste.

Description

Technical Field

[0001] The invention belongs to the technical field of restaurant kitchen waste treatment, and specifically relates to a method and system for resource utilization of all components of restaurant kitchen waste based on thermal hydrolysis. Background Art

[0002] How to balance the construction of urban ecological civilization with economic development has attracted more and more attention. In the process of urbanization, the classification and treatment of garbage has become the top priority of ecological civilization construction. Usually, urban wet garbage is mainly composed of food waste, which is food waste generated by residents in daily life and food processing, including vegetable leaves, leftovers, fruit peels and egg shells. With the improvement of the living standards of urban residents in my country, the amount of food waste generated has increased rapidly. The daily amount of food waste generated in major cities such as Shanghai, Beijing, Chongqing, and Guangzhou has exceeded 2,000 tons.

[0003] On the one hand, food waste contains a lot of water and organic matter, which is very easy to rot and deteriorate, spread bacteria and viruses, affect the environment and endanger people's health. On the other hand, it is also a serious waste of resources, especially in the case of energy shortage. Therefore, the development of food waste resource processing technology is of great significance to reduce pollution and provide clean renewable energy.

[0004] Most technologies make inadequate or uneconomical use of renewable resources in garbage. For example, lactic acid fermentation technology uses the nutrients such as reducing sugars, starch, and protein in food waste to produce lactic acid through anaerobic fermentation, and then synthesizes polylactic acid biodegradable plastics. This technology mainly develops and utilizes starch substances in garbage, but does not effectively regenerate and utilize the cellulose in the garbage, which has an increasing content. Another example is aerobic composting technology, which uses the physiological metabolic effects of a large number of aerobic microorganisms in an oxygen-rich environment to convert the difficult-to-decompose, large-molecule organic matter in food waste into easily absorbed, stable small-molecule organic matter. Organic matter is removed and humus biofertilizer is finally obtained, but the aerobic compost produced has disadvantages such as high land cost, long decomposition cycle and secondary pollution of leachate. The common feed technology is to use recyclable food waste as raw material to produce animal feed. The process is simple and occupies a small area, but the quality of the feed produced is unstable and the storage requirements are very strict. There is also a risk of homologous contamination, which can easily cause the spread of diseases. For the traditional landfill and incineration methods, although the operation is simple and easy, the biogas produced by the anaerobic decomposition of food waste has not been effectively collected and utilized, and its slow release into the atmosphere will also lead to global warming.

[0005] In short, one of the current technical difficulties in the field of food waste treatment is the inability to achieve efficient resource utilization of food waste. For example, lactic acid fermentation technology cannot recycle cellulose materials; aerobic composting methods cannot handle the large amount of leachate generated during the process, causing secondary pollution; direct animal feed processing seems to have fully realized the resource utilization of food waste, but the process actually cannot control the actual flow of food waste, and it may flow into the environment again as animal husbandry wastewater.

[0006] Thermal hydrolysis technology is a process of thermally cracking biomass with a macromolecular structure into small molecular liquid fuels under high temperature and high pressure with water as the reaction medium. The use of thermal hydrolysis treatment technology promotes the dissolution of solid organic matter in food waste, improves the gas production rate, and high temperature can kill pathogens, harmful microorganisms, parasite eggs, etc. However, if the appropriate hydrolysis temperature and pressure are not set, the organic matter in the food waste will not be completely dissolved to a large extent, resulting in a waste of resources in the food waste. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a method and system for resource utilization of all components of food waste based on thermal hydrolysis in view of the deficiencies in the above-mentioned prior art, which is used to solve the technical problem that food waste cannot be efficiently utilized as a resource, improve the utilization rate of food waste, reduce pollution and damage to the environment, and realize the resource utilization of food waste.

[0008] The present invention adopts the following technical solutions:

[0009] A full-component resource utilization system for kitchen waste based on thermal hydrolysis comprises a storage tank, which is respectively connected to a low-temperature thermal hydrolysis device and a high-temperature thermal hydrolysis device via a crushing and sorting device, and plastic products and metal products are separated by the crushing and sorting device.

[0010] Specifically, a preheating device is provided between the crushing and sorting device and the low-temperature thermal hydrolysis device and the high-temperature thermal hydrolysis device.

[0011] Furthermore, the preheating device includes an electrically heated reaction kettle, a hot air furnace and / or a steam heater.

[0012] In a second aspect, an embodiment of the present invention provides a method for resource utilization of all components of kitchen waste based on thermal hydrolysis, comprising the following steps:

[0013] S1. Sorting and crushing the food waste, crushing and separating the water-insoluble solid impurities in the food waste;

[0014] S2, recycling the plastic bags separated in step S1, and recycling the metals separated by gravity as metal products;

[0015] S3, preheating the kitchen waste after crushing and sorting in step S1 and performing low-temperature hot hydrolysis to separate the fat;

[0016] S4, preheating the kitchen waste after crushing and sorting in step S1 and performing high-temperature thermal hydrolysis to separate bio-oil;

[0017] S5. The aqueous phase product separated by thermal hydrolysis in step S3 and step S4 is configured as foliar fertilizer, and the solid phase residue is used as a soil conditioner.

[0018] Specifically, in step S1, the food waste includes plastic, metal, grease, protein and cellulose.

[0019] Furthermore, the sorted plastic products are recycled after being cleaned, and the metal products are recycled after being separated by gravity.

[0020] Specifically, in step S1, the crushing device includes a jaw crusher, a hammer crusher, and a knife crusher.

[0021] Specifically, in step S3, the reaction temperature of the low-temperature thermal hydrolysis is 140-180° C., the time is 30-60 minutes, and the reaction pressure is 0.5-2 MPa.

[0022] Specifically, in step S4, the reaction temperature of the high-temperature thermal hydrolysis is 280-360° C., the reaction time is 30-80 minutes, and the reaction pressure is 7-20 MPa.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] A full-component resource utilization system for kitchen waste based on thermal hydrolysis. The kitchen waste is crushed and sorted to obtain water-insoluble solid phase products, thereby realizing the recycling of plastic products and metal products; low-temperature thermal hydrolysis and high-temperature thermal hydrolysis are performed in a preheating device to separate grease and bio-oil, thereby realizing the recycling of oil phase products; the water phase products after thermal hydrolysis are used to make leaf fertilizers by adding trace elements, and the solid phase residues are used to prepare soil conditioners. The resource processing of solid phase debris, grease and wastewater in kitchen waste is realized, so that the kitchen waste can be effectively recycled and utilized, which is of great significance to reducing pollution and providing clean renewable energy.

[0025] Furthermore, the kitchen waste is preheated to a temperature for low-temperature thermal hydrolysis and high-temperature thermal hydrolysis by a preheating device.

[0026] A method for resource utilization of all components of food waste based on thermal hydrolysis realizes resource utilization of all components in food waste, including plastics, metals, oils, proteins and cellulose. Plastics and metals are inorganic impurities, which are sent to corresponding recycling and treatment stations for recycling after separation and cleaning; oil phase products are obtained after low-temperature thermal hydrolysis to realize oil recovery; bio-oil products are obtained after high-temperature thermal hydrolysis to realize protein, cellulose and other recovery. In addition, after the high-temperature thermal hydrolysis reaction, pathogenic bacteria and other substances in the food waste have been inactivated. Therefore, after the water phase product and solid phase product after the oil phase product are separated, the water phase product is used to prepare foliar fertilizer, and the solid phase product is used as a soil conditioner, realizing resource utilization of solid and liquid products.

[0027] Furthermore, taking full account of the current characteristics of food waste, a plastic and metal product separation and cleaning process is set up to clean up the residual food waste on plastic and metal products, so that plastic and metal products can be recycled.

[0028] Furthermore, the crushing process is performed to facilitate subsequent pulping and prevent large pieces of material from clogging the screen of the pulping machine.

[0029] In summary, the present invention realizes the resource utilization of all components in food waste, including plastics, metals, oils, proteins and cellulose, so that the food waste can be effectively recycled and utilized, which is of great significance to reducing pollution and providing clean renewable energy.

[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the present invention.

[0032] Among them: 1. Storage tank; 2. Crushing and sorting device; 3. Preheating device; 4. Low-temperature hot water hydrolysis device; 5. High-temperature hot water hydrolysis device; 6. Plastic products; 7. Metal products. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0035] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0036] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects are in an "or" relationship.

[0037] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0038] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0039] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0040] The present invention provides a method and system for resource utilization of all components of kitchen waste based on thermal hydrolysis. The kitchen waste is crushed and sorted to obtain water-insoluble solid phase products, thereby realizing the recycling of plastic products and metal products; low-temperature thermal hydrolysis and high-temperature thermal hydrolysis are performed in a preheating device to separate grease and bio-oil, thereby realizing the recycling of oil phase products; the water phase products after thermal hydrolysis are used to make leaf fertilizers by adding trace elements, and the solid phase residues are used to prepare soil conditioners. The resource processing of solid phase debris, grease and wastewater of kitchen waste is realized, so that the kitchen waste can be effectively recycled and utilized, which is of great significance to reducing pollution and providing clean renewable energy.

[0041] The present invention discloses a full-component resource utilization system for kitchen waste based on thermal hydrolysis, comprising a storage tank 1, a crushing and sorting device 2, a preheating device 3, a low-temperature thermal hydrolysis device 4, a high-temperature thermal hydrolysis device 5, a plastic product 6 and a metal product 7.

[0042] The storage tank 1 is connected to the low-temperature hot water hydrolysis device 4 and the high-temperature hot water hydrolysis device 5 respectively through the crushing and sorting device 2 and the preheating device 3, and the plastic products 6 and the metal products 7 are separated by the crushing and sorting device 2.

[0043] The kitchen waste enters the crushing and sorting device 2 through the storage tank 1, and the sorted plastics and metals are recycled into plastic products 6 and metal products. The sorted kitchen waste is passed into the preheating device 3 for low-temperature hot water hydrolysis device 4 and high-temperature hot water hydrolysis device 5 to separate grease and bio-oil. The aqueous phase product after hydrolysis is used to make leaf fertilizer, and the solid phase residue is used as soil conditioner.

[0044] See also Figure 1 The present invention provides a method for resource utilization of all components of kitchen waste based on thermal hydrolysis, comprising the following steps:

[0045] S1. Crushing and sorting

[0046] The water-insoluble solid products in all components of the food waste are crushed and separated through the crushing and sorting device. The separated plastic bags can be recycled as raw materials for plastic products; the separated metal products can be recycled.

[0047] All components of food waste include solid debris such as plastics and metals, and organic components such as oils, proteins, and cellulose.

[0048] The crushed and sorted plastic bags are cleaned in a cleaning tank and then recycled, and the metal debris is separated by gravity and then recycled into metal products.

[0049] Crushing and sorting devices include but are not limited to jaw crushers, hammer crushers, and knife crushers.

[0050] S2. Low temperature thermal hydrolysis

[0051] The kitchen waste separated in step S1 is passed into a preheating device for low-temperature thermal hydrolysis, and the separated oil is recycled.

[0052] The low-temperature hot water hydrolysis reaction temperature is 140-180°C, the reaction time is 30-60 minutes, and the reaction pressure is 0.5-2MPa.

[0053] S3. High temperature thermal hydrolysis

[0054] The kitchen waste separated in step S1 is passed into a preheating device for high-temperature thermal hydrolysis, and the separated bio-oil is recycled.

[0055] The high-temperature thermal hydrolysis reaction temperature is 260-320°C, the reaction time is 30-80 minutes, and the reaction pressure is 7-20MPa.

[0056] The protein and cellulose in the food waste are subjected to thermal hydrolysis reaction to produce oil in step S2 and step S3.

[0057] The preheating device of step S2 and step S3 includes but is not limited to an electric heating reactor, a hot air furnace, a steam heater, etc.

[0058] S4. Prepare fertilizer

[0059] The water phase product after the oil phase is separated by thermal hydrolysis can be prepared into foliar fertilizer that can be absorbed by plants by supplementing nitrogen, phosphorus, potassium and other elements, and the solid phase residue can be used as a soil conditioner.

[0060] In summary, the method and system for resource utilization of all components of kitchen waste based on thermal hydrolysis of the present invention realizes the resource utilization of all components in kitchen waste, including plastics, metals, oils, proteins and cellulose. Plastics and metals are inorganic impurities, which are sent to corresponding recycling and processing stations for recycling after separation and cleaning; oil phase products are obtained after low-temperature thermal hydrolysis to achieve oil recovery; bio-oil products are obtained after high-temperature thermal hydrolysis to achieve protein, cellulose and other recovery. In addition, after the high-temperature thermal hydrolysis reaction, pathogenic bacteria and other substances in the kitchen waste have been inactivated. Therefore, after the water phase product and the solid phase product after the oil phase product are separated, the water phase product is used to prepare foliar fertilizer, and the solid phase product is used as a soil conditioner, realizing the resource utilization of solid and liquid products.

[0061] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for resource utilization of all components of kitchen waste based on thermal hydrolysis, characterized in that: A system for resource utilization of all components of kitchen waste based on thermal hydrolysis comprises a storage tank (1), the storage tank (1) being connected to a low-temperature thermal hydrolysis device (4) and a high-temperature thermal hydrolysis device (5) respectively via a crushing and sorting device (2), the plastic products (6) and the metal products (7) being separated by the crushing and sorting device (2), a preheating device (3) being arranged between the crushing and sorting device (2) and the low-temperature thermal hydrolysis device (4) and the high-temperature thermal hydrolysis device (5), the preheating device (3) comprising an electric heating reactor, a hot air furnace and / or a steam heater; and a utilization method comprising the following steps: S1. Sorting and crushing the food waste, crushing and separating the water-insoluble solid impurities in the food waste; S2, recycling the plastic bags separated in step S1, and recycling the metals separated by gravity as metal products; S3, preheating the kitchen waste after crushing and sorting in step S1 and performing low-temperature hot water hydrolysis to separate the oil, the reaction temperature of the low-temperature hot water hydrolysis is 140-180° C., the time is 30-60 minutes, and the reaction pressure is 0.5-2MPa; S4, performing high-temperature thermal hydrolysis on the kitchen waste after crushing and sorting in step S1 after preheating to separate bio-oil, wherein the reaction temperature of the high-temperature thermal hydrolysis is 280-360° C., the reaction time is 30-80 minutes, and the reaction pressure is 7-20 MPa; S5. The aqueous phase product separated by thermal hydrolysis in step S3 and step S4 is configured into foliar fertilizer, and the solid phase residue is used as a soil conditioner.

2. The method for resource utilization of all components of kitchen waste based on thermal hydrolysis according to claim 1, characterized in that: In step S1, the food waste includes plastic, metal, grease, protein and cellulose.

3. The method for resource utilization of all components of kitchen waste based on thermal hydrolysis according to claim 2, characterized in that: The sorted plastic products are cleaned and recycled, and the metal products are recycled after gravity separation.

4. The method for resource utilization of all components of kitchen waste based on thermal hydrolysis according to claim 1, characterized in that: In step S1, the crushing devices include jaw crusher, hammer crusher and knife crusher.

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