Zero-emission kitchen waste oil utilization system and method

Abstract

The invention discloses a zero-emission kitchen waste oil utilization system and method, and relates to the field of kitchen waste resource utilization, the zero-emission kitchen waste oil utilization system comprises an emulsified oil rapid floating device, a surface floating oil lifting and collecting device, a waste oil chemical saponification treatment device and a residue cooperative treatment device, the emulsified oil rapid floating device comprises at least one super-oleophobic metal copper net which is obliquely arranged, and is used for intercepting and promoting emulsified oil drops in the wastewater to rapidly coalesce and float; the surface floating oil lifting and collecting device is arranged in an oil collecting channel at the tail end of the sewage pipe channel and is used for scraping and collecting surface floating oil in the oil collecting channel; according to the kitchen waste oil utilization system and method, oil-water separation is achieved through efficient cooperation of the emulsified oil rapid floating device and the surface floating oil lifting and collecting device, resource utilization is completed through chemical saponification treatment and residue cooperative fermentation, and finally kitchen waste oil recycling with zero emission in the whole process is achieved.

Description

Technical Field

[0001] This invention relates to the technology of resource utilization of kitchen waste, specifically to a zero-emission system and method for utilizing kitchen waste oil. Background Technology

[0002] With the rapid development of the catering industry, the treatment and disposal of waste cooking oil has become a critical issue that urgently needs to be addressed in the fields of environmental protection and food safety. Waste cooking oil mainly comes from grease traps and gutter oil in catering enterprises, food processing plants, and household kitchens. If not properly disposed of, it can not only cause water pollution and pipe blockage, but may also be recycled and processed by unscrupulous vendors and returned to the dining table, seriously threatening food safety and public health.

[0003] Currently, the main technologies for treating kitchen waste oil include physical separation technology and resource utilization technology.

[0004] In oil-water separation, grease traps are currently the most widely used primary treatment facility. Their basic principle is to utilize the density difference between grease and water, allowing the floating oil to rise to the surface and thus achieving separation. However, the treatment efficiency of grease traps is significantly affected by water flow velocity; when the flow rate is too high, the oil-water separation effect decreases significantly. Especially for emulsified oil in catering wastewater, due to its small droplet size and slow rising speed, a longer residence time is required in the grease trap for effective separation. In actual operation, especially under low-temperature conditions in winter, the kitchen waste oil easily cools and solidifies during its slow rising process, forming solid oil sludge that adheres to the tank walls and pipe inner walls. This not only affects the treatment effect but also leads to time-consuming and labor-intensive subsequent dredging and removal operations, resulting in high maintenance costs.

[0005] Regarding the resource utilization of waste cooking oil, existing technologies mainly involve the following treatment methods:

[0006] The first method is biological composting, which is suitable for smaller-scale processing. Its core process involves mixing kitchen waste oil with straw / sawdust and livestock manure in a specific ratio, piling the mixture into cones, and controlling the temperature for natural fermentation over 2-3 months. After fermentation, the product can be used as organic fertilizer for crops or flowers. The advantages of this method are its simplicity and low investment cost, but it also has drawbacks such as a long processing cycle, large land area required, and significant susceptibility to weather conditions.

[0007] The second method is microbial degradation. This method involves inoculating waste cooking oil with specialized lipolytic microorganisms, along with carbon and nitrogen sources. Under controlled temperature and pH conditions, aerobic fermentation is carried out for 5 to 7 days. Finally, the fermentation products are concentrated and dried to produce granular organic fertilizer. This method has the advantages of high processing efficiency and good fertilizer quality, but it produces greenhouse gas emissions such as carbon dioxide during the fermentation process, which is somewhat different from the current advocated low-carbon and environmentally friendly concept and makes it difficult to achieve true zero emissions.

[0008] The third method is chemical saponification. The core principle of this method is to mix kitchen waste oil with sodium hydroxide solution in a specific ratio, and under controlled temperature and reaction time, produce sodium fatty acid (soap base) and glycerol. Then, neutralizing agents such as ammonium dihydrogen phosphate and urea are added to adjust the pH value, and nutrients such as nitrogen, phosphorus, and potassium are supplemented. Finally, the mixture is dried and granulated to produce organic fertilizer. This method has mature technology and a controllable reaction, but in actual operation, the waste oil pretreatment process produces gum residue, and the saponification reaction process produces byproducts such as soap residue. Improper handling of these wastes can also cause secondary pollution, making it impossible to achieve clean production throughout the entire process.

[0009] In summary, existing kitchen waste oil treatment technologies still have significant shortcomings in terms of oil-water separation efficiency and zero emissions throughout the entire process. There is an urgent need to develop a kitchen waste oil recycling system that integrates efficient separation and resource utilization and can achieve zero emissions throughout the entire process. Summary of the Invention

[0010] The purpose of this invention is to provide a zero-emission system and method for utilizing kitchen waste oil, in order to solve the problems of low oil-water separation efficiency, secondary pollution during the treatment process, and inability to achieve zero emissions throughout the entire process in the existing technology.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a zero-emission kitchen waste oil utilization system, comprising an emulsified oil rapid flotation device, a surface floating oil lifting and collection device, a waste oil chemical saponification treatment device, and a residue co-treatment device arranged sequentially along the wastewater treatment flow direction, wherein:

[0012] The emulsified oil rapid flotation device is installed in the sewage pipe channel. It includes at least one inclined superoleophobic copper mesh. The emulsified oil rapid flotation device is used to intercept and promote the rapid aggregation and floating of emulsified oil droplets in the wastewater.

[0013] The surface oil lifting and collection device is installed in the oil collection channel at the end of the sewage pipe. The surface oil lifting and collection device is used to scrape and collect the surface oil in the oil collection channel. It includes a transverse moving module, a lifting module, a steel belt oil scraping module and a heated oil collection tank.

[0014] The waste oil chemical saponification treatment device includes a pretreatment reactor and a saponification reactor connected in series. The inlet of the pretreatment reactor is connected to the output end of the surface floating oil lifting and collecting device. The inner wall of the pretreatment reactor is equipped with a heating jacket. The pretreatment reactor is equipped with at least one quantitative filling port. The pretreatment reactor is equipped with a first stirring mechanism and a slag discharge port at the bottom. The inlet of the saponification reactor is connected to the outlet of the pretreatment reactor. The bottom of the saponification reactor is equipped with a glycerol outlet and a soap base outlet.

[0015] The residue co-processing device is a closed fermentation equipment, which is equipped with a feed inlet, an additive injection port, and an exhaust port. The feed inlet of the closed fermentation equipment is connected to the slag discharge port of the pretreatment reactor and the soap base discharge port of the saponification reactor, respectively.

[0016] Furthermore, the transverse module is mounted along the length of the oil collection channel. The transverse module is a ball screw linear assembly. A lifting module is installed on the sliding end of the transverse module. The telescopic end of the lifting module extends upward and connects to the steel belt oil scraping module.

[0017] Furthermore, the steel strip oil scraping module includes multiple sets of parallel oil scraping units, with the input ends of these units connected to the same drive component via couplings. By driving multiple sets of oil scraping units synchronously with a single motor, the consistency of each unit's operation is ensured, resulting in uniform and thorough oil scraping across the entire cross-section of the oil collection channel. Moreover, the parallel design allows for flexible adjustment of the number of oil scraping units based on the width of the oil collection channel, adapting to different scales of processing needs. Additionally, if any oil scraping unit malfunctions, it can be repaired individually without affecting the normal operation of other units, improving the equipment's reliability and ease of maintenance.

[0018] Furthermore, each oil scraping unit includes a cover plate, a steel belt circulation mechanism disposed within the cover plate, and an oil scraper disposed on the lower side of the cover plate, with an oil collection hopper disposed on the lower side of each oil scraper.

[0019] Furthermore, the lower ends of multiple oil collecting hoppers are connected to a heated oil collecting tank via pipelines, and the output end of the heated oil collecting tank is connected to a waste oil chemical saponification treatment device via an oil pump pipe. The heated oil collecting tank heats and keeps the collected floating oil at a constant temperature, effectively preventing the oil from cooling and solidifying at low temperatures, ensuring good fluidity of the oil, and guaranteeing smooth subsequent transportation.

[0020] Furthermore, the saponification reactor has metering ports for adding sodium hydroxide solution, neutralizing agent, and nutrients, respectively, and a second stirring mechanism is installed inside the reactor. Multiple metering ports allow for precise addition of different materials, ensuring accurate and controllable process parameters at each stage of the saponification reaction and neutralization process. The second stirring mechanism ensures thorough and uniform mixing of the reactants, improving saponification efficiency and neutralization effectiveness, and guaranteeing stable quality of the final soap base product.

[0021] Furthermore, the closed-loop fermentation equipment is equipped with a stirring mechanism and a heating and insulation layer inside the tank. A breather filter and a fermentation outlet are respectively installed at the top and bottom of the tank. The breather filter purifies the waste gas generated during fermentation and prevents odor leakage; the bottom fermentation outlet facilitates the smooth discharge of the decomposed fertilizer, achieving closed-loop, pollution-free operation.

[0022] A method for zero-emission recycling of kitchen waste oil using a kitchen waste oil utilization system includes the following steps:

[0023] S1. Rapid rise of emulsified oil: When oily wastewater flows into the sewage pipe and passes through the inclined superoleophobic copper mesh, the water phase passes through the copper mesh, and the emulsified oil droplets are intercepted and rapidly aggregate and rise to the water surface along the surface of the copper mesh.

[0024] S2. Surface oil collection: The oil that floats to the surface of the water gathers in the oil collection channel. The horizontal moving module drives the steel belt oil scraping module to move along the length of the oil collection channel. The lifting module adjusts the immersion depth of the steel belt according to the liquid level. The steel belt circulation mechanism rotates continuously to absorb the oil. The oil scraping plate scrapes the oil off the surface of the steel belt. The oil is collected in the oil collection hopper and then heated and kept warm in the heated oil collection tank before being transported to the waste oil chemical saponification treatment device.

[0025] S3. Waste oil chemical saponification treatment:

[0026] S31. Pretreatment steps: Waste oil enters the pretreatment reactor, is heated to 105-110℃ and stirred to dehydrate for 30-60 minutes, phosphoric acid is added to adjust the pH to 4-5, and after standing and separating into layers, the bottom sludge is discharged.

[0027] S32. Saponification reaction steps: The pretreated waste oil enters the saponification reactor. Sodium hydroxide solution is added at a mass ratio of waste oil: 30% sodium hydroxide solution = 1: 0.4-0.5. The temperature is raised to 80-90℃ and the mixture is stirred for 2-3 hours. After standing and separating into layers, glycerol is discharged from the bottom.

[0028] S33, Neutralization and Adjustment: After the saponification reaction is completed, add a neutralizing agent to the saponification reactor to adjust the pH to 6.5-7.5, and replenish nutrients.

[0029] S4. Co-processing of residue: The glue residue discharged from step S31 is mixed with the soap base discharged from step S33 in a certain proportion and then sent into a closed fermentation equipment. Carbon source, nitrogen source and pH adjuster are added, and the temperature is controlled to carry out composting fermentation to obtain organic fertilizer.

[0030] Compared with existing technologies, the present invention provides a zero-emission system and method for utilizing kitchen waste oil. On the one hand, through the synergistic effect of an emulsified oil rapid flotation device and a surface oil lifting and collection device, it significantly improves oil-water separation efficiency, solving the problems of poor separation effect and easy solidification and clogging at low temperatures in traditional grease traps. On the other hand, through a closed-loop design of waste oil chemical saponification treatment and residue co-treatment, it achieves resource utilization of waste and zero emissions throughout the entire process, avoiding secondary pollution. Specific technical effects include the following:

[0031] 1. The tilted superoleophobic copper mesh can quickly trap emulsified oil droplets and promote their coalescence and floating. Combined with the horizontal lifting steel belt oil scraping module, it dynamically collects surface oil, resulting in a significant improvement in separation efficiency compared to traditional oil separators. Moreover, there is no problem of oil residue solidification and clogging in low-temperature environments.

[0032] 2. The sludge and byproducts of the saponification reaction generated during pretreatment are all converted into fertilizer in a closed fermentation equipment, with no waste discharged. The fermentation process adopts a closed design combined with respiration filtration to avoid direct emission of greenhouse gases. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0034] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the emulsified oil rapid floating device and the surface floating oil lifting and collecting device in Embodiment 1 of the present invention;

[0036] Figure 3 This is a schematic diagram of the steel strip oil scraping module in Embodiment 1 of the present invention;

[0037] Figure 4 This is a schematic diagram of the waste oil chemical saponification treatment device and the residue co-treatment device in Embodiment 1 of the present invention;

[0038] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Emulsified oil rapid flotation device; 11. Adjustment mechanism; 2. Surface floating oil lifting and collection device; 21. Horizontal movement module; 22. Lifting module; 23. Steel belt oil scraping module; 231. Cover plate; 232. Steel belt circulation mechanism; 233. Oil scraper; 234. Oil collection hopper; 235. Heating oil collection tank; 3. Waste oil chemical saponification treatment device; 31. Pretreatment reactor; 32. Saponification reactor; 4. Residue co-treatment device. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] As attached Figure 1 As shown:

[0043] Example 1:

[0044] This invention provides a zero-emission kitchen waste oil utilization system, comprising an emulsified oil rapid flotation device 1, a surface floating oil lifting and collection device 2, a waste oil chemical saponification treatment device 3, and a residue co-treatment device 4, arranged sequentially along the wastewater treatment flow direction.

[0045] As attached Figure 2 To be continued Figure 3 As shown:

[0046] 1. In one embodiment of the present invention, the emulsified oil rapid flotation device 1 is disposed in a sewage pipe, and includes at least one inclined superoleophobic copper mesh. The emulsified oil rapid flotation device 1 is used to intercept and promote the rapid aggregation and flotation of emulsified oil droplets in the wastewater.

[0047] 2. In one embodiment of the present invention, the surface oil lifting and collecting device 2 is installed in the oil collection channel at the end of the sewage pipe. The surface oil lifting and collecting device 2 is used to scrape and collect the surface oil in the oil collection channel. It includes a transverse moving module 21, a lifting module 22, a steel strip oil scraping module 23, and a heated oil collection tank 235. The transverse moving module 21 is mounted along the length of the oil collection channel. The transverse moving module 21 is a ball screw linear assembly. The lifting module 22 is provided on the sliding end of the transverse moving module 21. The telescopic end of the lifting module 22 extends upward and connects to the steel strip oil scraping module 235. 3; The steel strip oil scraping module 23 includes multiple sets of parallel oil scraping units. The input ends of the multiple sets of oil scraping units are connected to the same driving component through a coupling. Each oil scraping unit includes a cover plate 231, a steel strip circulation mechanism 232 disposed in the cover plate 231, and an oil scraping plate 233 disposed on the lower side of the cover plate 231. Each oil scraping plate 233 is provided with an oil collection hopper 234 on its lower side. The lower ends of the multiple oil collection hoppers 234 are connected to a heated oil collection tank 235 through pipelines. The output end of the heated oil collection tank 235 is connected to the waste oil chemical saponification treatment device 3 through a pump oil pipe.

[0048] As attached Figure 1 Appendix Figure 4 As shown:

[0049] 3. In one embodiment of the present invention, the waste oil chemical saponification treatment device 3 includes a pretreatment reactor 31 and a saponification reactor 32 arranged in series. The inlet of the pretreatment reactor 31 is connected to the output end of the pump oil pipe. The inner wall of the pretreatment reactor 31 is provided with a heating jacket. The pretreatment reactor 31 is provided with at least one quantitative injection port. The pretreatment reactor 31 is provided with a first stirring mechanism. The bottom of the pretreatment reactor 31 is provided with a slag discharge port. The inlet of the saponification reactor 32 is connected to the outlet of the pretreatment reactor 31. The saponification reactor 32 is provided with quantitative injection ports for adding sodium hydroxide solution, neutralizing agent and nutrients, respectively. The saponification reactor 32 is provided with a second stirring mechanism. The bottom of the saponification reactor 32 is provided with a glycerol discharge port and a soap base discharge port.

[0050] 4. In one embodiment of the present invention, the residue co-processing device 4 is a closed fermentation device, which is provided with a feed inlet, an additive injection port, and an exhaust port. The feed inlet of the closed fermentation device is connected to the slag discharge port of the pretreatment reactor 31 and the soap base discharge port of the saponification reactor 32, respectively. The tank of the closed fermentation device is provided with a stirring mechanism and a heating and insulation layer. The top and bottom of the tank of the closed fermentation device are respectively provided with a breathing filter and a fermentation discharge port.

[0051] Working Principle: The zero-emission kitchen waste oil utilization system provided in Example 1 utilizes an inclined superoleophobic copper mesh in the emulsified oil rapid flotation device 1. This mesh, with its special wettability, achieves efficient water-oil separation, significantly increasing the coalescence and flotation speed of emulsified oil droplets. This solves the problems of low treatment efficiency and easy solidification and blockage of traditional grease traps. The surface oil lifting and collection device 2, through the coordinated operation of the transverse module 21, the lifting module 22, and multiple sets of parallel steel belt oil scraping units, achieves full-coverage scraping and collection of floating oil across the entire cross-section of the oil collection channel. The steel belt circulation mechanism 232 continuously absorbs floating oil, the scraper 233 effectively removes it, and the heated oil collection tank 235 heats and insulates the collected floating oil to prevent solidification, ensuring smooth transport of waste oil to subsequent treatment units. The waste oil chemical saponification treatment device 3, through the series connection of the pretreatment reactor 31 and the saponification reactor 32, allows the saponification reaction to proceed fully under medium-temperature conditions, resulting in high-purity saponification products and complete reaction. Glycerin and soap base are collected separately. The residue co-processing device 4 co-processes the pre-treated glue residue and the soap base produced by saponification in a closed fermentation equipment, adds auxiliary materials for aerobic fermentation, and converts the waste into organic fertilizer, achieving zero waste discharge from the entire system and reaching the goal of zero emissions.

[0052] As attached Figure 5 As shown:

[0053] Example 2:

[0054] This embodiment is basically the same as the previous embodiment, except that the tilt angle of the superoleophobic copper mesh in the emulsified oil rapid flotation device 1 is adjustable. The superoleophobic copper mesh of the emulsified oil rapid flotation device 1 is hinged between the two side walls of the sewage pipe via a rotating shaft. One end of the rotating shaft is connected to an adjustment mechanism 11 located on the outside of the pipe. The adjustment mechanism 11 flexibly adjusts the tilt angle of the copper mesh according to the real-time flow rate and oil content in the pipe, enabling the system to adapt to different processing requirements under different operating conditions: increasing the tilt angle to accelerate oil droplet flotation when the flow rate is high or the oil content is high, and decreasing the tilt angle to extend the contact time and improve the retention rate when the flow rate is low or the oil content is low. This adjustable tilt angle design further enhances the adaptability and processing efficiency of the emulsified oil rapid flotation device 1, ensuring optimal oil-water separation under different influent water quality conditions, thus optimizing and improving the overall system's operational stability and processing efficiency.

[0055] In conjunction with Embodiments 1 and 2 above, the present invention also provides a method for zero-emission recycling of kitchen waste oil using a kitchen waste oil utilization system, comprising the following steps:

[0056] S1. Rapid rise of emulsified oil: When oily wastewater flows into the sewage pipe and passes through the inclined superoleophobic copper mesh, the water phase passes through the copper mesh, and the emulsified oil droplets are intercepted and rapidly aggregate and rise to the water surface along the surface of the copper mesh.

[0057] S2. Surface oil collection: The oil that floats to the surface of the water gathers in the oil collection channel. The transverse module 21 drives the steel belt oil scraping module 23 to move along the length of the oil collection channel. The lifting module 22 adjusts the immersion depth of the steel belt according to the liquid level. The steel belt circulation mechanism 232 rotates continuously to absorb the oil. The oil scraping plate 233 scrapes the oil off the surface of the steel belt. The oil is collected in the oil collection hopper 234 and then fed into the heated oil collection tank 235 for heating and insulation before being transported to the waste oil chemical saponification treatment device 3.

[0058] S3. Waste oil chemical saponification treatment:

[0059] S31. Pretreatment steps: Waste oil enters the pretreatment reactor 31, is heated to 105-110℃ and stirred to dehydrate for 30-60 minutes, phosphoric acid is added to adjust the pH to 4-5, and after standing and separating into layers, the bottom sludge is discharged.

[0060] S32, Saponification reaction steps: The pretreated waste oil enters the saponification reactor 32. Sodium hydroxide solution is added at a mass ratio of waste oil: 30% sodium hydroxide solution = 1: 0.4~0.5. The temperature is raised to 80~90℃ and stirred for 2~3 hours. After standing and separating into layers, glycerol is discharged from the bottom.

[0061] S33, Neutralization and Adjustment: After the saponification reaction is completed, add a neutralizing agent to the saponification reactor 32 to adjust the pH to 6.5-7.5, and replenish nutrients.

[0062] S4. Co-processing of residue: The glue residue discharged from step S31 is mixed with the soap base discharged from step S33 in a certain proportion and then sent into a closed fermentation equipment. Carbon source, nitrogen source and pH adjuster are added, and the temperature is controlled to carry out composting fermentation to obtain organic fertilizer.

[0063] Example 3:

[0064] This embodiment is a further optimization based on the above-mentioned Embodiments 1 and 2. In order to achieve adaptive intelligent control of the system according to the real-time fluctuations of the influent conditions, this embodiment introduces an automated control system based on water quality monitoring. Specifically, in implementation, an online oil concentration detector and a flow meter are installed at the influent end of the sewage pipe, and a level gauge and a grease thickness detector are installed in the oil collection channel. All of the above online detection instruments are connected to the central controller. The central controller dynamically adjusts the copper mesh tilt angle of the emulsified oil rapid flotation device 1 and the operating speed of the surface oil lifting and collection device 2 according to the received real-time influent oil-water mixing ratio, total flow rate, and oil layer thickness in the oil collection channel.

[0065] Its regulatory logic is as follows:

[0066] Copper mesh tilt angle adjustment: When the influent flow rate increases or the oil concentration detector shows an increase in oil content in the water, the central controller determines that the system load has increased. At this time, the controller sends a command to the adjustment mechanism 11 to drive the rotating shaft to increase the tilt angle of the superoleophobic copper mesh. Increasing the tilt angle can accelerate the water flow rate, prevent solid impurities from excessively depositing on the mesh surface and clogging the mesh holes, and at the same time, the steeper slope promotes the rapid collision, aggregation, and floating of the intercepted emulsified oil droplets along the mesh surface to cope with the high load impact. Conversely, when the influent flow rate decreases or the oil concentration decreases, the controller reduces the copper mesh tilt angle, allowing the water flow to pass through more smoothly, prolonging the contact time between the oil droplets and the copper mesh, thereby improving the interception efficiency of trace emulsified oil.

[0067] Coordinated control of the oil scraper speed: The central controller adjusts the operating speed of the steel belt oil scraper module 23 using frequency conversion based on data from the grease thickness detector in the oil collection channel and the oil-water mixing ratio of the incoming water. Specifically, the oil concentration and flow rate of the incoming water are converted into a theoretical oil production rate, and combined with the actual floating oil thickness in the oil collection channel, a feedforward + feedback composite control is implemented. When the calculated grease production is high or the measured floating oil layer thickness increases too quickly, the controller increases the operating speed of the steel belt circulation mechanism 232 and adjusts the reciprocating frequency of the transverse module 21 accordingly to achieve rapid oil collection and prevent the floating oil from re-emulsifying or solidifying due to excessive residence time. When the grease production is low or the floating oil layer is thin, the speed of the oil scraper unit is reduced to avoid a large amount of water phase being stirred into the oil collection hopper 234, thereby improving the quality of collected waste oil and reducing the dehydration energy consumption of the subsequent waste oil chemical saponification treatment device 3.

[0068] Through the above-mentioned linkage control based on the inlet water-oil-water mixing ratio, density and flow rate parameters, Example 3 optimized the physical separation efficiency at the front end and achieved the best match between the oil collection speed and the incoming material load.

[0069] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A zero-emission kitchen waste oil utilization system, comprising an emulsified oil rapid flotation device (1), a surface floating oil lifting and collection device (2), a waste oil chemical saponification treatment device (3), and a residue co-treatment device (4) arranged sequentially along the wastewater treatment flow direction, characterized in that: The emulsified oil rapid flotation device (1) is installed in the sewage pipe channel, which includes at least one inclined superoleophobic metal copper mesh. The emulsified oil rapid flotation device (1) is used to intercept and promote the rapid aggregation and floating of emulsified oil droplets in the wastewater. The surface oil lifting and collection device (2) is installed in the oil collection channel at the end of the sewage pipe. The surface oil lifting and collection device (2) is used to scrape and collect the surface oil in the oil collection channel. It includes a transverse module (21), a lifting module (22), a steel belt oil scraping module (23), and a heated oil collection tank (235). The waste oil chemical saponification treatment device (3) includes a pretreatment reactor (31) and a saponification reactor (32) connected in series. The inlet of the pretreatment reactor (31) is connected to the output end of the surface floating oil lifting and collecting device (2). The inner wall of the pretreatment reactor (31) is provided with a heating jacket. The pretreatment reactor (31) is provided with at least one quantitative injection port. The pretreatment reactor (31) is provided with a first stirring mechanism. The bottom of the pretreatment reactor (31) is provided with a slag discharge port. The inlet of the saponification reactor (32) is connected to the outlet of the pretreatment reactor (31). The bottom of the saponification reactor (32) is provided with a glycerol outlet and a soap base outlet. The residue co-processing device (4) is a closed fermentation device with a feed inlet, an additive injection port and an exhaust port. The feed inlet of the closed fermentation device is connected to the slag discharge port of the pretreatment reactor (31) and the soap base discharge port of the saponification reactor (32), respectively.

2. The zero-emission kitchen waste oil utilization system according to claim 1, characterized in that, The transverse module (21) is mounted along the length of the oil collection channel. The transverse module (21) is a ball screw linear assembly. A lifting module (22) is provided on the sliding end of the transverse module (21). The telescopic end of the lifting module (22) extends upward and is connected to the steel strip oil scraping module (23).

3. The zero-emission kitchen waste oil utilization system according to claim 2, characterized in that, The steel strip oil scraping module (23) includes multiple sets of oil scraping units arranged in parallel, and the input ends of the multiple sets of oil scraping units are connected to the same driving component through a coupling.

4. The zero-emission kitchen waste oil utilization system according to claim 3, characterized in that, Each of the oil scraping units includes a cover plate (231), a steel belt circulation mechanism (232) disposed in the cover plate (231), and an oil scraping plate (233) disposed on the lower side of the cover plate (231). An oil collection hopper (234) is provided on the lower side of each oil scraping plate (233).

5. The zero-emission kitchen waste oil utilization system according to claim 4, characterized in that, The lower ends of the multiple oil collecting hoppers (234) are connected to the heated oil collecting tank (235) through pipelines, and the output end of the heated oil collecting tank (235) is connected to the waste oil chemical saponification treatment device (3) through the oil pump pipe.

6. The zero-emission kitchen waste oil utilization system according to claim 1, characterized in that, The saponification reactor (32) has quantitative injection ports for adding sodium hydroxide solution, neutralizing agent and nutrient elements, respectively, and a second stirring mechanism is provided inside the saponification reactor (32).

7. A zero-emission kitchen waste oil utilization system according to claim 1, characterized in that, The closed fermentation equipment is equipped with a stirring mechanism and a heating and insulation layer inside the tank. A breathing filter and a fermentation outlet are respectively installed at the top and bottom of the tank.

8. A method for zero-emission recycling of kitchen waste oil using the kitchen waste oil utilization system according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Rapid rise of emulsified oil: When oily wastewater flows into the sewage pipe and passes through the inclined superoleophobic copper mesh, the water phase passes through the copper mesh, and the emulsified oil droplets are intercepted and rapidly aggregate and rise to the water surface along the surface of the copper mesh. S2. Surface oil collection: The oil that floats to the surface of the water gathers in the oil collection channel. The horizontal moving module (21) drives the steel belt oil scraping module (23) to move along the length of the oil collection channel. The lifting module (22) adjusts the immersion depth of the steel belt according to the liquid level. The steel belt circulation mechanism (232) rotates continuously to absorb the oil. The oil scraping plate (233) scrapes the oil off the surface of the steel belt and collects it in the oil collection hopper (234) into the heated oil collection tank (235). After heating and heat preservation, it is transported to the waste oil chemical saponification treatment device (3). S3. Waste oil chemical saponification treatment: S31, Pretreatment steps: Waste oil enters the pretreatment reactor (31), is heated to 105-110℃ and stirred to dehydrate for 30-60 minutes, phosphoric acid is added to adjust the pH to 4-5, and after standing and separating into layers, the bottom sludge is discharged. S32, Saponification reaction steps: The pretreated waste oil enters the saponification reactor (32), and sodium hydroxide solution is added at a mass ratio of waste oil: 30% sodium hydroxide solution = 1: 0.4~0.

5. The temperature is raised to 80~90℃ and stirred for 2~3 hours. After standing and separating into layers, glycerol is discharged from the bottom. S33, Neutralization and Adjustment: After the saponification reaction is completed, add a neutralizing agent to the saponification reactor (32) to adjust the pH to 6.5-7.5, and supplement the nutrients; S4. Co-processing of residue: The glue residue discharged from step S31 is mixed with the soap base discharged from step S33 in a certain proportion and then sent into a closed fermentation equipment. Carbon source, nitrogen source and pH adjuster are added, and the temperature is controlled to carry out composting fermentation to obtain organic fertilizer.

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