Kitchen waste full-cycle recycling system

Abstract

The invention discloses a full-cycle recycling system for kitchen waste, which is characterized in that the kitchen waste is extruded to break bags, the effective separation of oversize products and undersize products is realized, then the kitchen waste is crushed to carry out solid-liquid separation, the liquid phase is subjected to oil-water separation, and water and oil are recycled. One part of the solid phase is subjected to anaerobic fermentation to generate biogas, solid residues obtained after anaerobic fermentation are prepared into an organic fertilizer through an aerobic composting device, the other part of the solid phase is mixed with oversize products and post-biochar for pyrolysis, generated pyrolysis gas is subjected to hydrogen purification, and the purified pyrolysis gas is subjected to solid-liquid separation; the generated high-salt biochar is used for recycling salt in a heating evaporative crystallization mode, the biochar is used as an adsorption material and a soil improvement material after being dried, and the biochar is used for field returning planting through organic fertilizer and the biochar, so that the harmless and environment-friendly effects are achieved. According to the method, the kitchen waste can be rapidly reduced on a large scale, the treatment capacity is high, resource utilization and energy utilization are sufficient, and good economic benefits and environmental benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of garbage disposal, and in particular to a full-circulation recycling system for kitchen waste. Background Art

[0002] Kitchen waste is a general term for leftover food discarded by families, hotels, restaurants, government agencies, enterprises and institutions, and is a type of kitchen waste generated during people's daily consumption. Kitchen waste may include but is not limited to: oil, water, fruit peels, vegetables, rice, fish, meat, bones, shells, and waste tableware, knives, glass containers, metal objects, plastics, paper towels, etc.

[0003] At present, both at home and abroad have begun to explore new technologies for the treatment of food waste, and the number of food waste treatment projects is gradually increasing. The main treatment methods are: 1) Crushing and direct discharge. This method refers to crushing the food waste, and then discharging it into the sewer pipe under the drive of water flow, and entering the sewage plant together with other urban domestic sewage for unified treatment. This technology has low cost and simple operation, which can reduce the water content of domestic waste and reduce the amount of domestic waste to be treated; 2) Landfill treatment. Domestic waste and food waste are sent to a landfill far away from urban residential areas for unified landfill. This method is low-cost, and food waste is easy to decompose, with little impact on residents' lives. However, the water content of food waste is high, which will increase the amount of leachate produced in the landfill and affect the quality of soil and groundwater. In addition, this method occupies a large area of ​​land and is gradually abandoned by various countries; 3) Energy treatment. That is, incineration of food waste to generate electricity can effectively utilize the energy contained in the waste, but the treatment process will cause pollution and is not economical.

[0004] The Chinese patent with the prior art publication number CN113695357A discloses a full-cycle recycling system for restaurant kitchen waste, which obtains paste-like waste after being crushed by a restaurant kitchen waste crusher; the paste-like waste is separated into powdered crushed waste by a processor, and water and oil are separated for recycling; the crushed waste is mixed with perishable waste such as pig manure and duck manure and then injected into a centralized warehouse for fermentation, and the biogas generated by the fermentation can be used for power generation, and the fermented organic fertilizer is used for returning to the field for planting, thereby achieving a harmless and environmentally friendly effect.

[0005] The above patents recycle resources only through mixed fermentation to produce biogas, mixed composting and recycling of water and oil. There are problems such as low efficiency of large-scale processing, insufficient resource utilization, insufficient energy utilization, etc., and they cannot meet the growing demand for solid waste treatment.

[0006] Therefore, the applicant proposes a full-cycle recycling system for kitchen waste to solve the above problems. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention aims to provide a full-cycle recycling system for kitchen waste.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A full-cycle recycling system for kitchen waste, comprising the following steps:

[0010] S1. Squeeze and break the food waste bags, magnetically separate the metals in the food waste, and effectively separate the plastic, wooden tableware and paper towels in the food waste as the sieve-up materials and the remaining food waste as the sieve-down materials;

[0011] S2, crushing the kitchen waste, adding water and spraying it to generate a mixture of water and solid particles;

[0012] S3, separating the mixture into solid and liquid to obtain solid particles and oily wastewater;

[0013] S4, separating the oil-containing wastewater into oil and water to obtain oil and wastewater, wherein the oil is used as a chemical raw material to produce industrial fatty acid products, and the wastewater is used for cleaning, spraying and planting water after being purified by biochar adsorption;

[0014] S5, subjecting a portion of the solid particulate matter to anaerobic fermentation to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set, and the solid residue is aerobically composted to obtain organic fertilizer, and another portion of the solid particulate matter is mixed with the screened material obtained in S1 and the biochar obtained after adsorption and purification of wastewater in S4, and subjected to low-temperature pyrolysis treatment to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification treatment, and the high-salt biochar is subjected to cooling treatment;

[0015] S6, dissolving the soluble salt in the high-salt biochar, and then separating the solid and the liquid to obtain desalted biochar and a salt solution;

[0016] S7, using flue gas indirect heating evaporation crystallization method to recover the salt in the liquid as a chemical raw material, and recycling the aqueous solution obtained after steam condensation;

[0017] S8, drying the desalinated biochar obtained in S6, returning 30-40% of the obtained product as soil improvement material and the organic fertilizer obtained in S5 to the field for planting to produce grain and vegetables, and recycling 60-70% of the obtained product as adsorption material to be used in S4 as wastewater adsorption and purification material;

[0018] S9. Food waste will be generated again after processing of grains and vegetables.

[0019] Furthermore, the oil-water separation method in S4 is a conventional oil-water gravity separation method or a centrifugal separation method; the wastewater is treated by biochar adsorption, and the addition amount is controlled to be a solid-liquid mass ratio of 1:18 to 1:12.

[0020] Furthermore, the power generation by the generator set in S5 is used for the operation of low-temperature pyrolysis, and a part of the pyrolysis gas generated by the low-temperature pyrolysis can also be used by the generator set to generate power.

[0021] Furthermore, the temperature of anaerobic fermentation in S5 is 30-40°C, and the temperature of aerobic composting is 50-60°C.

[0022] Furthermore, another part of the solid particles in S5 is mixed with the screen material and the biochar after adsorption and purification of wastewater, and the mixing time is 40 to 60 minutes; the high-salt biochar is cooled by indirect cooling.

[0023] Furthermore, the hydrogen purification method in S5 is a composite purification method, in which the pyrolysis gas is sequentially subjected to cyclone dust removal and condensation dehydration to remove particulate matter and moisture, and then CO2 and CH4 are separated by pressure swing adsorption, so as to finally obtain hydrogen with a purity of ≥99.5%.

[0024] Furthermore, in S6, a water-soluble process is adopted, the mixing ratio of biochar and water is 1:8 by solid-liquid mass ratio, and the water temperature is 25-35° C.; the solid-liquid separation method is centrifugal separation, plate and frame filter pressing or vacuum filtration.

[0025] Furthermore, the salt-containing solution in S7 is evaporated and crystallized by indirect heating with flue gas to recover the salt in the liquid as a chemical raw material. The steam is used to mix and heat the water in S2 and control the temperature of anaerobic fermentation and aerobic composting. The aqueous solution obtained after condensation and the purified wastewater are stored in water storage tanks respectively.

[0026] Furthermore, the flue gas generated after the combustion of the biogas in S5 is used as the heat source of the evaporation and crystallization salt extraction device in S7, and the waste heat of the flue gas exhaust is used for drying the biochar in S8. The used flue gas exhaust is purified by the exhaust gas purification method, and the flue gas exhaust is sequentially passed through electrostatic dust removal, ozone oxidation denitrification, limestone slurry desulfurization and wet electrostatic dust removal, and finally discharged through the chimney to meet the emission standards.

[0027] Further, it includes a bag-breaking extrusion device, a crushing device, a first solid-liquid separation device, an oil-water separation device, a crude oil cylinder, a purification device, a second solid-liquid separation device, a water storage tank, an anaerobic fermentation device, a generator set, an aerobic composting device, a mixing device, a low-temperature pyrolysis device, a hydrogen purification device, a hydrogen storage tank, a cooling device, a salt dissolving device, a third solid-liquid separation device, a salt extraction device, a salt storage bin, a drying device, a biochar storage bin, an exhaust gas purification device, a chimney and a sprinkler;

[0028] The kitchen waste is squeezed and broken by the squeezing bag breaking device, the metal in the kitchen waste is magnetically separated, and the plastic, wooden tableware and paper towels in the kitchen waste are taken as the sieve-up materials, and the remaining kitchen waste is taken as the sieve-down materials for effective separation;

[0029] The kitchen waste is crushed by a crushing device and sprayed by a sprayer to generate a mixture of water and solid particles;

[0030] Passing the mixture through a first solid-liquid separation device for solid-liquid separation to obtain solid particles and oily wastewater;

[0031] The oily wastewater is separated into oil and water by an oil-water separation device to obtain oil and wastewater, wherein the oil is stored in a crude oil drum and used as a chemical raw material to produce industrial fatty acid products, and the wastewater is used for washing, spraying and planting water after adsorption and purification by a purification device, and the purified water is separated into solid and liquid by a second solid-liquid separation device to obtain post-biochar and purified water, and the purified water is stored in a water storage tank;

[0032] Anaerobic fermentation of a portion of the solid particulate matter is performed through an anaerobic fermentation device to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set, and the solid residue is used to produce organic fertilizer through an aerobic composting device, and another portion of the solid particulate matter is mixed with the oversize material and post-biochar in a mixing device, and low-temperature pyrolysis treatment is performed through a low-temperature pyrolysis device to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification treatment, and the purified hydrogen is stored in a hydrogen storage tank, and the high-salt biochar is cooled through a cooling device;

[0033] The high-salt biochar is passed through a salt dissolving device to dissolve the soluble salt therein, and then the biochar is separated into solid and liquid by a third solid-liquid separation device to obtain desalted biochar and a salt solution;

[0034] The salt solution is transported to the salt extraction device, and the flue gas generated by the combustion of biogas is indirectly heated to evaporate and crystallize, and the salt in the liquid is recovered and stored in the salt storage bin as a chemical raw material. The aqueous solution obtained after the steam condensation is recycled;

[0035] The desalinated biochar is transported to a drying device and dried by the waste heat of flue gas. The flue gas after use is purified by tail gas and finally discharged through a chimney in compliance with the emission standards. The dried biochar is stored in a biochar storage bin, and 30-40% of the obtained product is used as soil improvement material and organic fertilizer for returning to the field for planting to produce grain and vegetables, and 60-70% of the obtained product is recycled back to the purification device as an adsorption material.

[0036] Food waste will be generated again after grain and vegetable processing.

[0037] Compared with the prior art, the present invention provides a full-cycle recycling system for kitchen waste, which has the following beneficial effects:

[0038] 1. The present invention uses kitchen waste as raw materials, squeezes and breaks the bags of kitchen waste, recycles metals in the kitchen waste, and effectively separates the sieve material and the sieve material, then crushes the kitchen waste and separates the solid and liquid, separates the liquid phase into oil and water, and recycles the water and oil; a part of the solid phase is subjected to anaerobic fermentation to produce biogas, which is used for power generation by a generator set, and the solid residue after anaerobic fermentation is passed through an aerobic composting device to obtain organic fertilizer; another part of the solid phase is mixed with the sieve material and post-biochar for pyrolysis, the generated pyrolysis gas is purified by hydrogen through a hydrogen purification process, the generated high-salt biochar is recycled by heating evaporation and crystallization, and the biochar is used as an adsorption material and soil improvement material after drying to achieve recycling; the organic fertilizer and biochar are used for returning to the field for planting, thereby achieving harmless and environmentally friendly effects; the present invention can achieve rapid and large-scale reduction of kitchen waste, has large processing capacity, high efficiency, full resource utilization, full energy utilization, can well meet the growing demand for solid waste treatment, and has good economic and environmental benefits.

[0039] 2. The purified water recovered by the present invention is used for washing, spraying and planting, and the biochar is used as an adsorption material and soil improvement material, which fully realizes the high-value utilization of by-products in the process of food waste disposal.

[0040] 3. In the present invention, a part of the solid phase is mixed with the oversize material and post-biochar for pyrolysis, thereby improving the pore structure of the biochar, decomposing the organic matter, and leaving the salt in the biochar, thus laying a foundation for subsequent salt extraction.

[0041] 4. The present invention can achieve complete elimination of harmful substances (such as bacteria, microorganisms and antibiotic pollutants), effective solidification of heavy metals, and a clean and environmentally friendly process.

[0042] 5. The biochar obtained by extracting salt in the present invention has rich pore structures and functional groups and good adsorption properties. It can be used to adsorb and purify salt, ammonia nitrogen, COD, etc. in wastewater, and can also be used to adsorb pollutants such as organic matter and heavy metals in wastewater. At the same time, biochar is rich in N, P, K and other elements, and is a good biological fertilizer and soil improvement material. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a flowchart of a full-cycle recycling system for restaurant kitchen waste.

[0044] Markings in the figure: 1. Extrusion bag breaking device; 2. Crushing device; 3. First solid-liquid separation device; 4. Oil-water separation device; 5. Crude oil drum; 6. Purification device; 7. Second solid-liquid separation device; 8. Water storage tank; 9. Anaerobic fermentation device; 10. Generator set; 11. Aerobic composting device; 12. Mixing device; 13. Low-temperature pyrolysis device; 14. Hydrogen purification; 141. Cyclone dust removal device; 142. Condensation and dehydration device; 1 43. Pressure swing adsorption device; 15. Hydrogen storage tank; 16. Cooling device; 17. Salt dissolving device; 18. Third solid-liquid separation device; 19. Salt extraction device; 20. Salt storage bin; 21. Drying device; 22. Biochar storage bin; 23. Tail gas purification; 231. Electrostatic precipitator; 232. Ozone oxidation denitrification device; 233. Limestone slurry desulfurization device; 234. Wet electrostatic precipitator; 24. Chimney; 25. Sprinkler. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0046] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the instructions and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. Machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0047] It should be noted that the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0048] The embodiment of the present invention provides a full-cycle recycling system for kitchen waste, referring to Figure 1 , including the following steps:

[0049] S1. Squeeze and break the food waste bags, magnetically separate the metals in the food waste, and effectively separate the plastic, wooden tableware and paper towels in the food waste as the sieve-up materials and the remaining food waste as the sieve-down materials;

[0050] S2, crushing the kitchen waste, adding water and spraying it to generate a mixture of water and solid particles;

[0051] S3, separating the mixture into solid and liquid to obtain solid particles and oily wastewater;

[0052] S4, separating the oil-containing wastewater into oil and water to obtain oil and wastewater, wherein the oil is used as a chemical raw material to produce industrial fatty acid products, and the wastewater is used for cleaning, spraying and planting water after being purified by biochar adsorption;

[0053] S5, subjecting a portion of the solid particulate matter to anaerobic fermentation to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set, and the solid residue is aerobically composted to obtain organic fertilizer, and another portion of the solid particulate matter is mixed with the screened material obtained in S1 and the biochar obtained after adsorption and purification of wastewater in S4, and subjected to low-temperature pyrolysis treatment to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification treatment, and the high-salt biochar is subjected to cooling treatment;

[0054] S6, dissolving the soluble salt in the high-salt biochar, and then separating the solid and the liquid to obtain desalted biochar and a salt solution;

[0055] S7, using flue gas indirect heating evaporation crystallization method to recover the salt in the liquid as a chemical raw material, and recycling the aqueous solution obtained after steam condensation;

[0056] S8, drying the desalinated biochar obtained in S6, returning 30-40% of the obtained product as soil improvement material and the organic fertilizer obtained in S5 to the field for planting to produce grain and vegetables, and recycling 60-70% of the obtained product as adsorption material to be used in S4 as wastewater adsorption and purification material;

[0057] S9. Food waste will be generated again after processing of grains and vegetables.

[0058] Specifically, the kitchen waste in S1 is squeezed and broken by a disc-type squeeze bag breaker, which squeezes and breaks the kitchen waste (punctures the plastic bag but does not break it), flattens mineral water bottles, beverage bottles, various cans, etc., smashes porcelain and glass bottles, smashes vegetable residues in organic waste, etc. The upper part of the machine is also equipped with a magnetic separator + manipulator, which is used to magnetically separate the metals in the kitchen waste, and the plastic, wooden tableware and paper towels after the bag is broken are taken out by the disk as the sieve-surface material, and the squeezed kitchen residue passes through the sieve hole as the sieve-underface material and automatically falls into the crushing device 2 from the discharge port.

[0059] The water temperature in S2 is room temperature, and the water can be sprayed through the sprayer 25, and the sprayer 25 can be provided with a plurality of spray heads.

[0060] The wastewater in S4 can be used for cleaning other devices, as spray water for the sprinkler 25, and as water for returning to the field for planting after being purified by biochar adsorption.

[0061] The low-temperature pyrolysis treatment temperature in S5 is 300-500°C; during anaerobic fermentation, the solid particles can be placed in a sterilization box for high-temperature sterilization, and then the sterilized solid particles are placed in an anaerobic fermentation device 9, and anaerobic bacteria are added to the anaerobic fermentation device 9 for fermentation; during aerobic composting, the solid residue is placed in an aerobic composting device 11, and biological bacteria are added to the aerobic composting device 11, and stirred to obtain organic fertilizer; the biogas is burned to generate electricity for the generator set, and the flue gas generated by the combustion indirectly heats the salt solution in S7 for evaporation and crystallization; the high-salt biochar is cooled by air.

[0062] The drying temperature in S8 is 110-150°C.

[0063] In this embodiment, the oil-water separation method in S4 is a conventional oil-water gravity separation method or a centrifugal separation method; the wastewater is treated by biochar adsorption, and the addition amount is controlled to be a solid-liquid mass ratio of 1:18 to 1:12.

[0064] In this embodiment, the power generation by the generator set in S5 is used for the operation of low-temperature pyrolysis, and a part of the pyrolysis gas generated by the low-temperature pyrolysis can also be used by the generator set to generate power.

[0065] In this embodiment, the temperature of anaerobic fermentation in S5 is 30-40°C, and the temperature of aerobic composting is 50-60°C.

[0066] In this embodiment, another part of the solid particles in S5 is mixed with the screen material and the biochar after adsorption and purification of wastewater, and the mixing time is 40 to 60 minutes; the high-salt biochar is cooled by indirect cooling.

[0067] Reference Figure 1 In this embodiment, the hydrogen purification method in S5 is a composite purification method, in which the pyrolysis gas is sequentially subjected to cyclone dust removal and condensation dehydration to remove particulate matter and moisture, and then CO2 and CH4 are separated by pressure swing adsorption, so as to finally obtain hydrogen with a purity of ≥99.5%.

[0068] Specifically, the hydrogen purification 14 needs to be applied to a cyclone dust removal device 141, a condensation and dehydration device 142, a pressure swing adsorption device 143 and a tail gas recovery energy supply unit, the cyclone dust removal device 141 is a cyclone dust collector, the condensation and dehydration device 142 is a condensation tower, the pressure swing adsorption device 143 is a pressure swing adsorption (PSA) tower (the adsorbent is molecular sieve-13X), and the tail gas recovery energy supply unit is an internal combustion engine or a fuel cell;

[0069] In the low temperature pyrolysis device 13, at 300-500°C in the absence of oxygen, microwave assisted pyrolysis (power density 0.5-2kW / m 3) and an iron-based catalyst (Fe / CeO2) to convert the food waste into pyrolysis gas (H2 content 12%-18%, CO content 8%-15%, CH4 content 5%-10%) and biochar, wherein the food waste is mixed with the iron-based catalyst (Fe / CeO2, mass ratio 1:0.3), and the microwave power density is set to 1kW / m 3 The pyrolysis temperature gradient is controlled at 350℃ (10min) → 450℃ (20min) → 500℃ (15min), and the pyrolysis gas is rapidly cooled to below 200℃ to inhibit tar formation;

[0070] Then the pyrolysis gas is passed through a cyclone dust removal device 141 to remove particles with a particle size greater than 10 μm, and then condensed and dehydrated at -5°C by a condensation and dehydration device 142, with a dew point of ≤-10°C, and operated at a pressure of 2-5 bar by a pressure swing adsorption (PSA) tower, with an adsorption cycle of 8 hours and a desorption cycle of 4 hours, and a hydrogen recovery rate of ≥98%. Then, the unpurified methane and CO mixed gas (CH4 content 8%-12%, CO content 7%-10%) can be used for power generation by an internal combustion engine or energy supply by a fuel cell, so as to realize energy cascade utilization, with a thermal efficiency of ≥35%;

[0071] Through the above-mentioned low-temperature pyrolysis treatment method, microwave heating and catalyst work synergistically, the pyrolysis temperature is reduced by 40%, and the hydrogen yield is increased to more than 15%; through the above-mentioned hydrogen purification method, cyclone dust removal + condensation dehydration removes more than 80% of impurities, the PSA operating cost is reduced by 30%, and the exhaust gas recovery energy supply system reduces external energy consumption, and the overall energy efficiency reaches more than 85%.

[0072] In this embodiment, a water-soluble process is used in S6, the mixing ratio of biochar to water is a solid-liquid mass ratio of 1:8, and the water temperature is 25-35°C; the solid-liquid separation method is centrifugal separation, plate and frame filter press or vacuum filtration.

[0073] Reference Figure 1 In this embodiment, the salt solution in S7 is evaporated and crystallized by indirect heating with flue gas to recover the salt in the liquid as a chemical raw material. The steam is used to mix and heat the water in S2 and control the temperature of anaerobic fermentation and aerobic composting. The aqueous solution obtained after condensation and the purified wastewater are stored in the water storage tank 8 respectively.

[0074] Specifically, the aqueous solution obtained after condensation and the purified waste water are stored together in the water tank 8. A partition can be set in the water tank 8. The aqueous solution obtained after condensation is stored on one side of the partition in the water tank 8, and the purified waste water is stored on the other side of the partition in the water tank 8. The temperature of the aqueous solution obtained after condensation is 40-60°C. When the condensed aqueous solution is reused in the salt dissolving device 17, it can be used together with purified water to reduce the temperature of the condensed aqueous solution; part of the steam can directly enter the sprayer 25 and mix with the water in the sprayer 25 to heat the water.

[0075] Reference Figure 1 In this embodiment, the flue gas generated after the combustion of the biogas in S5 is used as the heat source of the evaporation crystallization salt extraction device in S7, and the waste heat of the flue gas exhaust is used for drying the biochar in S8. The flue gas exhaust after use is purified by the exhaust gas purification method, and the flue gas exhaust is sequentially passed through electrostatic dust removal, ozone oxidation denitrification, limestone slurry desulfurization and wet electrostatic dust removal, and finally discharged through the chimney to meet the standards.

[0076] Specifically, the tail gas purification 23 needs to be applied to an electrostatic precipitator 231, an ozone oxidation denitrification device 232, a limestone slurry desulfurization device 233, and a wet electrostatic precipitator 234; the electrostatic precipitator 231 is an electrostatic precipitator, the ozone oxidation denitrification device 232 is an ozone oxidation denitrification furnace, the limestone slurry desulfurization device 233 is a limestone slurry desulfurization tower, and the wet electrostatic precipitator 234 is a wet electrostatic precipitator;

[0077] The high voltage electric field of the electrostatic precipitator 231 charges and adsorbs the particles, the ozone oxidation denitrification device 232 performs denitrification, the limestone slurry desulfurization device 233 performs desulfurization, and the water film of the wet electrostatic precipitator 234 flushes the electrodes to enhance the capture of fine particles, so that the exhaust gas meets the emission index: PM < 5mg / m 3 , SO2<35mg / m 3 , NOx<50mg / m 3 (Ultra-low emission standard), which can achieve a pollutant removal rate of > 99% in flue gas and exhaust gas, while promoting the transformation of industrial waste gas treatment towards resource utilization and low carbonization.

[0078] Reference Figure 1 In this embodiment, it includes a bag extrusion device 1, a crushing device 2, a first solid-liquid separation device 3, an oil-water separation device 4, a crude oil cylinder 5, a purification device 6, a second solid-liquid separation device 7, a water storage tank 8, an anaerobic fermentation device 9, a generator set 10, an aerobic composting device 11, a mixing device 12, a low-temperature pyrolysis device 13, a hydrogen purification device 14, a hydrogen storage tank 15, a cooling device 16, a salt dissolving device 17, a third solid-liquid separation device 18, a salt extraction device 19, a salt storage bin 20, a drying device 21, a biochar storage bin 22, an exhaust gas purification device 23, a chimney 24 and a sprinkler 25;

[0079] Specifically, the extrusion bag breaking device 1 is a disc-type extrusion bag breaking machine; the crushing device 2 is a crusher; the first solid-liquid separation device 3, the second solid-liquid separation device 7 and the third solid-liquid separation device 18 are plate and frame filter presses or belt filter presses; the oil-water separation device 4 is a gravity or centrifugal oil-water separation device; the purification device 6 is a static adsorption device or a dynamic adsorption column; the anaerobic fermentation device 9 is an anaerobic fermentation tank; the aerobic composting device 11 is an aerobic composting tank; the mixing device 12 is a spiral ribbon mixer, a plow mixer or a double-shaft mixer; the low-temperature pyrolysis device 13 is a drum-type indirect pyrolysis furnace with its own furnace; the cooling device 16 is a drum-type indirect cooling device or a spiral indirect cooling device; the salt dissolving device 17 is a common mixing and dissolving device; the salt extraction device 19 is a drum-type indirect heating evaporation salt extraction device; the drying device 21 is a drum drying device, a belt drying device or a disc drying device.

[0080] The kitchen waste is squeezed and broken by the squeezing bag breaking device 1 (the plastic bag is punctured but not broken), and mineral water bottles, beverage bottles, various cans are flattened, porcelain and glass bottles are smashed, and vegetable residues in organic waste are smashed. The upper part of the machine is also equipped with a magnetic separator + manipulator to magnetically separate the metals in the kitchen waste and recycle the metals. The plastic, wooden tableware and paper towels after the bag is broken are taken out by the passive disc as the screen material, and the squeezed kitchen waste passes through the sieve hole as the screen material and automatically falls into the crushing device 2 from the discharge port;

[0081] The kitchen waste is crushed by the crushing device 2 and sprayed by the sprayer 25 to generate a mixture of water and solid particles;

[0082] The mixture is passed through a first solid-liquid separation device 3 for solid-liquid separation to obtain solid particles and oily wastewater;

[0083] The oily wastewater is separated into oil and water by an oil-water separation device 4 to obtain oil and wastewater, wherein the oil is stored in a crude oil cylinder 5 and used as a chemical raw material to produce industrial fatty acid products. The wastewater is purified by adsorption by a purification device 6 and used for washing, spraying and planting. The purified water is separated into solid and liquid by a second solid-liquid separation device 7 to obtain post-biochar and purified water, and the purified water is stored in a water storage tank 8;

[0084] A portion of the solid particulate matter is subjected to anaerobically fermentation by an anaerobic fermentation device 9 to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set 10, and the solid residue is produced into organic fertilizer by an aerobic composting device 11, and another portion of the solid particulate matter is mixed with the oversize material and post-biochar in a mixing device 12, and subjected to low-temperature pyrolysis treatment by a low-temperature pyrolysis device 13 to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification 14, and the purified hydrogen is stored in a hydrogen storage tank 15, and the high-salt biochar is cooled by a cooling device 16;

[0085] The high-salt biochar is passed through a salt dissolving device 17 to dissolve the soluble salt therein, and then the biochar is passed through a third solid-liquid separation device 18 for solid-liquid separation to obtain desalted biochar and a salt solution;

[0086] The salt solution is transported to the salt extraction device 19, and the flue gas generated by the combustion of biogas is indirectly heated and evaporated and crystallized, and the salt in the liquid is recovered and stored in the salt storage bin 20 as a chemical raw material. The aqueous solution obtained after the steam condensation is recycled;

[0087] The desalinated biochar is transported to the drying device 21 and dried by the waste heat of flue gas. The flue gas after use passes through the tail gas purification 23 and is finally discharged through the chimney 24 to meet the emission standards. The dried biochar is stored in the biochar storage bin 22. 30-40% of the obtained product is used as soil improvement material and organic fertilizer for returning to the field to produce grain and vegetables. 60-70% of the obtained product is recycled as adsorption material and used in the purification device 6.

[0088] Food waste will be generated again after grain and vegetable processing.

[0089] The kitchen waste can be transported between the devices through a conveying device, which includes but is not limited to a slurry pump, a high-angle belt conveyor, a scraper conveyor, a bucket elevator, a screw conveyor, a common fan, a common flue gas fan, a water pump or an oil pump, etc.

[0090] In summary, the present invention can achieve rapid large-scale reduction of restaurant kitchen waste, has large processing capacity, high efficiency, full resource utilization, full energy utilization, can well meet the growing demand for solid waste treatment, and has good economic and environmental benefits.

[0091] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A full-cycle recycling system for kitchen waste, characterized in that: The steps include: S1. Squeeze and break the food waste bags, magnetically separate the metals in the food waste, and effectively separate the plastic, wooden tableware and paper towels in the food waste as the sieve-up materials and the remaining food waste as the sieve-down materials; S2, crushing the kitchen waste, adding water and spraying it to generate a mixture of water and solid particles; S3, separating the mixture into solid and liquid to obtain solid particles and oily wastewater; S4, separating the oil-containing wastewater into oil and water to obtain oil and wastewater, wherein the oil is used as a chemical raw material to produce industrial fatty acid products, and the wastewater is used for cleaning, spraying and planting water after being purified by biochar adsorption; S5, subjecting a portion of the solid particulate matter to anaerobic fermentation to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set, and the solid residue is aerobically composted to obtain organic fertilizer, and another portion of the solid particulate matter is mixed with the screened material obtained in S1 and the biochar obtained after adsorption and purification of wastewater in S4, and subjected to low-temperature pyrolysis treatment to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification treatment, and the high-salt biochar is subjected to cooling treatment; S6, dissolving the soluble salt in the high-salt biochar, and then separating the solid and the liquid to obtain desalted biochar and a salt solution; S7, using flue gas indirect heating evaporation crystallization method to recover the salt in the liquid as a chemical raw material, and recycling the aqueous solution obtained after steam condensation; S8, drying the desalinated biochar obtained in S6, returning 30-40% of the obtained product as soil improvement material and the organic fertilizer obtained in S5 to the field for planting to produce grain and vegetables, and recycling 60-70% of the obtained product as adsorption material to be used in S4 as wastewater adsorption and purification material; S9. Food waste will be generated again after processing of grains and vegetables.

2. The full-cycle recycling system for kitchen waste according to claim 1 is characterized in that: The oil-water separation method in S4 is a conventional oil-water gravity separation method or a centrifugal separation method; the wastewater is treated by biochar adsorption, and the addition amount is controlled to be a solid-liquid mass ratio of 1:18 to 1:

12.

3. The full-cycle recycling system for kitchen waste according to claim 1 is characterized in that: In S5, the generator set generates electricity for low-temperature pyrolysis operation, and a portion of the pyrolysis gas generated by low-temperature pyrolysis can also be used to generate electricity for the generator set.

4. The full-cycle recycling system for kitchen waste according to claim 1 is characterized in that: The temperature of the anaerobic fermentation in S5 is 30-40°C, and the temperature of the aerobic composting is 50-60°C.

5. The full-cycle recycling system for restaurant kitchen waste according to claim 1 is characterized in that: Another part of the solid particles in S5 is mixed with the screen material and the biochar after adsorption and purification of wastewater, and the mixing time is 40 to 60 minutes; the high-salt biochar cooling method is indirect cooling.

6. The full-cycle recycling system for restaurant kitchen waste according to claim 1 is characterized in that: The hydrogen purification method in S5 is a composite purification method, in which the pyrolysis gas is sequentially subjected to cyclone dust removal and condensation dehydration to remove particulate matter and moisture, and then CO2 and CH4 are separated by pressure swing adsorption, so as to finally obtain hydrogen with a purity of ≥99.5%.

7. The full-cycle recycling system for restaurant kitchen waste according to claim 1 is characterized in that: In the S6, a water-soluble process is adopted, the mixing ratio of biochar to water is 1:8 by solid-liquid mass ratio, and the water temperature is 25-35° C.; the solid-liquid separation method is centrifugal separation, plate and frame filter press or vacuum filtration.

8. The full-cycle recycling system for food waste according to claim 4 is characterized in that: The salt solution in S7 is evaporated and crystallized by indirect heating with flue gas, and the salt in the liquid is recovered as a chemical raw material. The steam is used to mix and heat the water in S2 and control the temperature of anaerobic fermentation and aerobic composting. The aqueous solution obtained after condensation and the purified wastewater are stored in water storage tanks respectively.

9. The full-cycle recycling system for restaurant kitchen waste according to claim 1 is characterized in that: The flue gas generated after the combustion of the biogas in S5 is used as the heat source for the evaporation and crystallization salt extraction device in S7, and the waste heat of the flue gas exhaust is used for drying the biochar in S8. The flue gas exhaust after use is purified by the exhaust gas purification method, and the flue gas exhaust is sequentially passed through electrostatic dust removal, ozone oxidation denitrification, limestone slurry desulfurization and wet electrostatic dust removal, and finally discharged through the chimney to meet the standards.

10. The full-cycle recycling system for kitchen waste according to claim 9, characterized in that: It comprises a bag-breaking device (1), a crushing device (2), a first solid-liquid separation device (3), an oil-water separation device (4), a crude oil cylinder (5), a purification device (6), a second solid-liquid separation device (7), a water storage tank (8), an anaerobic fermentation device (9), a generator set (10), an aerobic composting device (11), a mixing device (12), a low-temperature pyrolysis device (13), a hydrogen purification device (14), a hydrogen storage tank (15), a cooling device (16), a salt dissolving device (17), a third solid-liquid separation device (18), a salt extraction device (19), a salt storage bin (20), a drying device (21), a biochar storage bin (22), an exhaust gas purification device (23), a chimney (24) and a sprinkler (25); The kitchen waste is squeezed and broken by a squeezing bag breaking device (1), metals in the kitchen waste are magnetically separated, and plastics, wooden tableware and paper towels in the kitchen waste are taken as the sieve-surface material, and the remaining kitchen waste is taken as the sieve-surface material for effective separation; The kitchen waste is crushed by a crushing device (2) and sprayed by a sprayer (25) to generate a mixture of water and solid particles; Passing the mixture through a first solid-liquid separation device (3) for solid-liquid separation to obtain solid particles and oily wastewater; The oily wastewater is passed through an oil-water separation device (4) for oil-water separation treatment to obtain oil and wastewater, wherein the oil is stored in a crude oil cylinder (5) and used as a chemical raw material to produce industrial fatty acid products, and the wastewater is used for washing, spraying and planting water after adsorption and purification by a purification device (6). The purified water is passed through a second solid-liquid separation device (7) for solid-liquid separation to obtain post-biochar and purified water, and the purified water is stored in a water storage tank (8); Anaerobic fermentation of a portion of the solid particles is performed in an anaerobic fermentation device (9) to obtain biogas and solid residue, wherein the biogas is used for power generation by a generator set (10), and the solid residue is used to produce organic fertilizer by an aerobic composting device (11); another portion of the solid particles is mixed with the screen material and post-biochar in a mixing device (12), and low-temperature pyrolysis treatment is performed in a low-temperature pyrolysis device (13) to obtain pyrolysis gas and high-salt biochar, wherein the pyrolysis gas is subjected to hydrogen purification (14), and the purified hydrogen is stored in a hydrogen storage tank (15), and the high-salt biochar is cooled by a cooling device (16); The high-salt biochar is passed through a salt dissolving device (17) to dissolve the soluble salt therein, and then the biochar is passed through a third solid-liquid separation device (18) for solid-liquid separation to obtain desalted biochar and a salt-containing solution; The salt solution is transported to a salt extraction device (19), and the flue gas generated after the combustion of biogas is indirectly heated to evaporate and crystallize, and the salt in the liquid is recovered and stored in a salt storage bin (20) as a chemical raw material. The aqueous solution obtained after the steam condensation is recycled; The desalinated biochar is transported to a drying device (21) and dried by the waste heat of flue gas. The flue gas after use passes through a tail gas purification device (23) and is finally discharged through a chimney (24) in compliance with the emission standards. The dried biochar is stored in a biochar storage bin (22). 30-40% of the obtained product is used as a soil improvement material and organic fertilizer for returning to the field for planting to produce grain and vegetables. 60-70% of the obtained product is recycled as an adsorption material and used in the purification device (6). Food waste will be generated again after grain and vegetable processing.

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