Kitchen waste oil extraction optimization method and system

Abstract

The application discloses a kind of kitchen garbage oil extraction optimization method and system, wherein the method comprises the following steps: S1, the kitchen garbage is pretreated, by mixing again to kitchen garbage and its exuded leachate, so that the water content of the kitchen garbage after pretreatment is kept in the range of 50%~65% beneficial to oil extraction;S2, the oil extraction is carried out to the kitchen garbage after pretreatment.The method of the application can keep the water content of the kitchen garbage after pretreatment in the range beneficial to oil extraction by redistributing the leachate exuded from the kitchen garbage and optimizing the pretreatment process of the kitchen garbage, thereby significantly improving the oil extraction rate of the kitchen garbage and effectively increasing the economic benefits brought by the kitchen garbage.

Description

TECHNICAL FIELD

[0001] The present application relates to kitchen waste oil extraction, in particular to a kitchen waste oil extraction optimization method and system. BACKGROUND

[0002] Kitchen waste refers to the garbage generated in daily life and food processing, catering services, unit catering and other activities, including discarded vegetable leaves, leftovers, fruit peels, eggshells, tea dregs, bones, etc. Its main sources are household kitchens, restaurants, hotels, canteens, markets and other food processing related industries. The oil content of kitchen waste is not high, and the oil extraction rate of each ton of kitchen waste is only 0.8% to 1.2%. However, the oil extraction rate can be an important indicator of kitchen waste resource utilization.

[0003] The industrial oil extracted from kitchen waste can be used to produce biodiesel, which can become a biofuel for internal combustion engines, a typical "green energy". According to relevant data, according to the current technical level, 500 kg of biodiesel can be extracted from 600 kg of "water oil". The use of biodiesel can reduce the emission of harmful gases from city motor vehicles by 70%. The recycling of kitchen waste will drive the development of related industries and increase the government's tax revenue. In the face of the potential kitchen waste recycling market driven by the catering industry, this part of the tax revenue is one of the contributions to the government's revenue. However, the existing kitchen waste treatment method generally has the problem of low oil extraction rate. SUMMARY

[0004] The purpose of the present application is to solve the technical problem of low oil extraction rate of kitchen waste in the prior art, and to provide a kitchen waste oil extraction optimization method and system.

[0005] The technical problem of the present application is solved by the following technical scheme:

[0006] A kitchen waste oil extraction optimization method, comprising the following steps:

[0007] S1, pretreating the kitchen waste to seep out the leachate;

[0008] S2, monitoring the water content of the pretreated kitchen waste in real time, and partially remixing the kitchen waste and its seepage leachate according to the change of the water content; wherein the mixing ratio of the leachate is adjusted according to the real-time monitoring of the water content of the pretreated kitchen waste, so that the water content of the pretreated kitchen waste is always kept within the range of 50% to 65%, so as to facilitate oil leaching;

[0009] S3, oil extraction of the pretreated kitchen waste.

[0010] In some embodiments, the following technical features are further included:

[0011] The partial remixing of the kitchen waste and the leachate exuded therefrom in step S2 includes the following steps:

[0012] S21, collecting and storing the leachate exuded from the kitchen waste, the leachate including the leachate exuded from the kitchen waste in the garbage collection device and the leachate exuded after the kitchen waste enters the receiving hopper;

[0013] S22, mixing the kitchen waste and the leachate at a preset ratio, and obtaining garbage slurry through large material sorting treatment;

[0014] S23, performing extrusion dewatering treatment on the garbage slurry;

[0015] S24, monitoring the water content of the garbage slurry before and after the extrusion dewatering in real time, and adjusting the mixing ratio of the kitchen waste and the leachate in step S22 according to the change of the water content of the garbage slurry.

[0016] In step S22, the preset ratio of the kitchen waste to the leachate is 2:1, and in step S24, the mixing ratio of the kitchen waste to the leachate is adjusted in the range of 4:3 to 8:3.

[0017] In step S24, the water content of the garbage slurry before the extrusion dewatering is determined by the hydraulic pressure value of the plunger pump, if the hydraulic pressure value of the plunger pump is higher than the preset threshold value, the ratio of the leachate is increased, and if the hydraulic pressure value of the plunger pump is lower than the preset threshold value, the ratio of the leachate is decreased.

[0018] The preset threshold value of the hydraulic pressure value of the plunger pump is 15-17 Mpa.

[0019] The change of the water content of the garbage slurry after the extrusion dewatering is determined by the current value of the extrusion dewatering device, if the current value of the extrusion dewatering device is higher than the preset threshold value, the ratio of the leachate is increased, and if the current value of the extrusion dewatering device is lower than the preset threshold value, the ratio of the leachate is decreased.

[0020] The preset threshold value of the current value of the extrusion dewatering device is 15-20 A.

[0021] The present application also provides the following technical solutions:

[0022] A kitchen waste oil extraction optimization system, comprising a kitchen waste pretreatment module and an oil extraction device; the kitchen waste pretreatment module is pretreated by the steps of the above method; the oil extraction device extracts oil from the pretreated kitchen waste.

[0023] The kitchen garbage pretreatment module further comprises a garbage collecting device, a receiving hopper, a leachate storage device, a leachate lifting pump, a crushing device, a plunger pump and an extrusion dewatering device; the garbage collecting device is used for placing the kitchen garbage to be pretreated; the receiving hopper is used for receiving the kitchen garbage in the garbage collecting device and conveying the kitchen garbage to the crushing device; the leachate storage device is used for collecting the leachate seeping from the kitchen garbage in sequence through the garbage collecting device and the receiving hopper; the leachate lifting pump is used for pumping the leachate in the leachate storage device into the crushing device to be mixed with the kitchen garbage; the crushing device is used for performing large material sorting treatment on the kitchen garbage to obtain garbage slurry; the plunger pump is used for pumping the garbage slurry into the extrusion dewatering device; and the extrusion dewatering device is used for performing extrusion dewatering treatment on the garbage slurry.

[0024] In some embodiments, the following technical features are further included:

[0025] The control device is configured to regulate the amount of leachate output by the leachate lifting pump according to the hydraulic pressure value fed back by the plunger pump and the current value fed back by the extrusion dewatering device, so as to regulate the mixing ratio of the leachate and the kitchen garbage.

[0026] The beneficial effects of the present application compared with the prior art include:

[0027] The kitchen garbage oil extraction optimization method provided by the present application can realize that the water content of the pretreated kitchen garbage is always maintained within the range of 50% to 65% which is beneficial to oil extraction, thereby significantly improving the oil extraction rate of the kitchen garbage and effectively increasing the economic benefits brought by the kitchen garbage.

[0028] In addition, in some embodiments, the following beneficial effects are further included:

[0029] The present application embodiment collects and stores the leachate of the kitchen garbage, uniformly distributes the leachate, and judges the change of the water content of the garbage slurry before and after extrusion dewatering by the hydraulic pressure value of the plunger pump and the current value of the extrusion dewatering device in sequence, so as to ensure that the water content of the kitchen garbage is always maintained within the range of 50% to 65% which is beneficial to oil extraction, thereby realizing automatic regulation of the mixing ratio of the kitchen garbage after leachate and the kitchen garbage leachate, and compared with the existing method of setting personnel to observe the dry and wet state of the garbage slurry on site, the present application embodiment realizes precise regulation of the mixing ratio of the kitchen garbage after leachate and the kitchen garbage leachate, significantly improves the oil extraction rate, and reduces the labor cost.

[0030] Other beneficial effects of the present application embodiment will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a kind of kitchen garbage oil extraction optimization method flow chart provided by the embodiment of the present application;

[0032] Figure 2 is a kind of kitchen garbage oil extraction optimization system schematic diagram provided by the embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described below with reference to the drawings and in conjunction with preferred embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0034] Before introducing the embodiments of the present application, the idea of the present application is described as follows:

[0035] The general kitchen garbage pretreatment process is: "material receiving + large material sorting (crushing and pulping) + extrusion dewatering + sand and impurity removal + three-phase separation". The large material sorting is a crucial step in the kitchen garbage pretreatment system, and it can remove 10% to 15% of large materials and has a certain garbage crushing effect. The extraction rate of kitchen garbage oil is related to the water content of the garbage. According to the different conditions of kitchen garbage, the water content of kitchen garbage fluctuates greatly. After kitchen garbage is drained and enters the material receiving section, part of the water is filtered out. Therefore, the water content of kitchen garbage entering the large material sorting stage is too low, which leads to insufficient water content of the garbage slurry obtained after the kitchen garbage is sorted by large materials, resulting in poor oil leaching effect of kitchen garbage.

[0036] In order to solve the problem of poor oil leaching effect of kitchen garbage in the above-mentioned existing method, the embodiment of the present application provides a method for improving the extraction rate of kitchen garbage oil. The method of the embodiment collects, stores and redistributes the kitchen garbage leachate, so that the water content of the crushed garbage slurry is maintained in the range most beneficial to oil leaching, thereby achieving the effect of increasing the oil leaching of the crushed garbage slurry of kitchen garbage without additional water and improving the extraction rate of kitchen garbage oil.

[0037] EMBODIMENT

[0038] The embodiment of the present application specifically provides a kitchen garbage oil extraction optimization method, as shown in Figure 1 The method comprises the following steps:

[0039] S1, pretreating kitchen garbage to seep out leachate;

[0040] S2. Real-time monitoring of the moisture content of the pretreated kitchen waste, and partially remixing the kitchen waste and the leachate therefrom according to changes in the moisture content; wherein the ratio of the leachate mixture is regulated according to the real-time monitored moisture content of the pretreated kitchen waste, so that the moisture content of the pretreated kitchen waste is always maintained within the range of 50% to 65%, thereby facilitating oil leaching;

[0041] S3. Extracting oil from the pre-treated kitchen waste.

[0042] Partially remixing the kitchen waste and the leachate therefrom in step S2 includes the following steps:

[0043] S21. Collecting and storing leachate leaked from the kitchen waste using a leachate storage device, the leachate including leachate leaked from the kitchen waste in the waste collection device and leachate leaked after the kitchen waste enters the receiving hopper. Specifically, the leachate storage device is configured as a leachate collection and storage tank. After the kitchen waste enters the receiving hopper, some water leaks out (generally, the receiving hopper in the treatment process has a waste drain function), forming leachate, which is then collected and stored in the leachate collection and storage tank.

[0044] S22. Mix the kitchen waste with the leachate according to a preset ratio, and obtain a garbage slurry through large-matter sorting and processing; set an outlet at the bottom of the leachate collection and storage tank and connect one or more leachate lifting pumps; the leachate lifting pump pumps the leachate through a pipeline into the crushing device; the receiving hopper receives the kitchen waste in the garbage collection device and transports it to the crushing device. Because the leachate contains broken shell particles that can easily clog the pipeline, in some preferred embodiments, a filter can be added or the leachate can be allowed to settle. The type and lift of the leachate lifting pump are selected according to actual conditions, and a variable frequency centrifugal pump is generally selected; because impurities in the leachate can affect the oil extraction rate, a high impurity content in the leachate will lead to insufficient water distribution. Under the condition that the pipeline flow rate remains unchanged, a high impurity content in the leachate will inevitably lead to a decrease in the water content of the garbage slurry after the kitchen waste is crushed. Specifically, the kitchen waste and leachate are mixed in a preset ratio of 2:1, and the mixture is processed through large-matter sorting to obtain a garbage slurry. In some embodiments, the crushing device adopts a large-matter sorting device, and the outlet of the leachate lifting pump is connected to the feed port of the large-matter sorting device with a pipe, and a flow meter is provided to ensure the ratio of kitchen waste and leachate. The flow meter is connected to a remote PLC controller (Programmable Logic Controller, PLC). The controller is also used to control the amount of kitchen waste raw material input after drainage.

[0045] S23. The crushed garbage slurry is injected from a lower position into a higher extrusion dehydration device through a plunger pump, and the extrusion dehydration device performs extrusion dehydration treatment on the garbage slurry.

[0046] S24, monitoring the water content of the garbage slurry before and after the extrusion dewatering in real time, and adjusting the mixing ratio of the kitchen garbage and the leachate in step S12 according to the change of the water content of the garbage slurry. Specifically, the water content of the garbage slurry before and after the extrusion dewatering is monitored in real time by the following two ways:

[0047] (1) The dry and wet is judged by the hydraulic pressure of the plunger pump. When the hydraulic pressure of the plunger pump is too large, it indicates that the garbage slurry of the garbage crushing device is dry and the water content is low. When the hydraulic pressure of the plunger pump is too small, it indicates that the garbage slurry of the garbage crushing device is wet and the water content is high. The normal range of the hydraulic pressure of the plunger pump is generally 15-17Mpa.

[0048] (2) When the garbage is extruded and dewatered by the spiral, the effect of the extrusion dewatering is judged according to the current fluctuation of the extrusion dewatering device. Too wet or too dry is not allowed. When the current of the extrusion dewatering machine is too large, the spiral propulsion is blocked and the current rises, indicating that the water content of the garbage slurry is too low. On the contrary, when the water content of the garbage slurry is high, the current of the extrusion dewatering machine is lower than the normal value. The normal range of the current is generally 15-20A.

[0049] By monitoring the water content of the garbage slurry before and after the extrusion dewatering, the water content of the kitchen garbage can be kept in the range of 50%-65% which is beneficial to the oil extraction when the oil is extracted, so as to maximize the oil extraction rate.

[0050] The embodiment of the present application also provides a kitchen garbage oil extraction optimization system, such as Figure 2As shown, the kitchen waste pretreatment module includes a kitchen waste pretreatment module, a grease extraction device; the kitchen waste pretreatment module is pretreated by the steps of the above method; the grease extraction device extracts grease from the pretreated kitchen waste. The kitchen waste pretreatment module further comprises: a garbage collection device, a receiving hopper, a leach storage device, a leach lifting pump, a crushing device, a plunger pump, an extrusion dewatering device, a control device; the garbage collection device is placed in the kitchen waste to be pretreated; the receiving hopper receives the kitchen waste in the garbage collection device and transports it to the crushing device; the leach storage device collects the leach from the kitchen waste in turn through the garbage collection device and the receiving hopper; the leach lifting pump pumps the leach in the leach storage device into the crushing device and mixes with the kitchen waste; the crushing device separates the kitchen waste into large material and obtains garbage slurry; the plunger pump pumps the garbage slurry into the extrusion dewatering device; the extrusion dewatering device extrudes and dewatering the garbage slurry; the control device includes a PLC controller, which adjusts the amount of leach output by the leach lifting pump according to the hydraulic pressure value fed back by the plunger pump and the current value fed back by the extrusion dewatering device, thereby adjusting the ratio of leach and kitchen waste. After the garbage slurry is extruded and dewatered by the extrusion dewatering device, it enters the sand and impurity removal device for sand and impurity removal treatment, and then enters the three-phase separation device for three-phase separation to remove solids and water, obtaining crude grease. The crude grease is purified by the grease extraction device to obtain purified grease.

[0051] Test example

[0052] The kitchen waste is extracted by the method of the present embodiment and the existing method respectively, and the test results are shown in Table 1. The grease extraction rate of each ton of kitchen waste after pretreatment by the method of the present embodiment is increased from 0.8% to 1.2% to 1.5% to 1.8%, and the extracted grease can be recycled (for example: used for aviation oil), which is expected to increase annual income by 1 million to 1.5 million yuan, bringing significant economic benefits. In addition, after saponification of the grease, some substances such as solid sterols, high molecular alcohols, hydrocarbons, pigments and fat-soluble vitamins are not soluble in water but soluble in organic solvents, which are collectively referred to as unsaponifiable matter. The content of unsaponifiable matter in the grease should be limited within a certain range. The higher the content of unsaponifiable matter, the worse the quality of the grease. The test results show that the moisture content and impurity content of the grease extracted by the existing method is 1% to 3%, while the moisture content and impurity content of the grease extracted by the method of the present embodiment is only 0.1% to 0.38%; the unsaponifiable matter content of the grease extracted by the existing method is 3% to 7%, while the unsaponifiable matter content of the grease extracted by the method of the present embodiment is only 1.49% to 1.70%; the acid value of the grease extracted by the existing method is 37.9 to 38.3 mg / g, while the acid value of the grease extracted by the method of the present embodiment is only 13.9 to 14.0 mg / g, thus it can be seen that the quality of the grease extracted by the method of the present embodiment has also been significantly improved.

[0053] Table 1

[0054] Oil extraction rate Moisture and impurity content Unsaponifiable matter content Acid value Prior art method 0.8％～1.2％ 1％-3％ 3％-7％ 37.9-38.3 mg / g The method of the present example 1.5％～1.8％ 0.1％～0.38％ 1.49％～1.70％ 13.9-14.0 mg / g

[0055] The method of the embodiment is tested on the basis of raw kitchen garbage (kitchen garbage after draining) and the ratio of kitchen garbage:drainage (8:3 to 4:3), and the effect of oil extraction is the best.

[0056] Compared with the prior art method, the method of the embodiment also has the following advantages:

[0057] 1. The water used is kitchen garbage filtrate, and no other external water is used, which reduces the cost of kitchen garbage end sewage treatment;

[0058] 2. The method of the embodiment uses less equipment and is simple to operate, which is conducive to large-scale popularization and use.

[0059] The above content is a further detailed description of the present application in combination with specific / preferred embodiments, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, they can make several substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered as belonging to the protection scope of the present application. In the description of the present application, the description of the reference terms "one embodiment", "some embodiments", "preferred embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In the case of no mutual contradiction, the skilled person in the art can combine and combine the different embodiments or examples described in the present application and the features of different embodiments or examples. Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made in this paper without departing from the scope of the patent application.

Claims

1. A method for optimizing the extraction of oil and fat from kitchen waste, characterized in that, It comprises the following steps: S1, pretreating the kitchen garbage, and seeping out the leachate; S2, monitoring the moisture content of the pretreated kitchen garbage in real time, and re-mixing the kitchen garbage and the leachate seeped out therefrom according to the change of the moisture content; The mixing ratio of the leachate is adjusted according to the real-time monitoring of the moisture content of the pretreated kitchen garbage, so that the moisture content of the pretreated kitchen garbage is always kept within the range of 50% to 65%, which is beneficial to the oil leaching; S3, extracting oil from the pretreated kitchen garbage; The re-mixing of the kitchen garbage and the leachate in step S2 comprises the following steps: S21, collecting and storing the leachate seeped out from the kitchen garbage, which comprises the leachate seeped out from the kitchen garbage in the garbage collection device and the leachate seeped out from the kitchen garbage after entering the receiving hopper; S22, mixing the kitchen garbage and the leachate according to the preset mixing ratio, and obtaining the garbage slurry through the large material sorting treatment; S23, performing the extrusion dewatering treatment on the garbage slurry; S24, monitoring the moisture content of the garbage slurry before and after the extrusion dewatering in real time, and adjusting the mixing ratio of the kitchen garbage and the leachate in step S22 according to the change of the moisture content of the garbage slurry; The moisture content of the garbage slurry before the extrusion dewatering is determined by the hydraulic pressure value of the plunger pump, if the hydraulic pressure value of the plunger pump is higher than the preset threshold value, the mixing ratio of the leachate is increased, and if the hydraulic pressure value of the plunger pump is lower than the preset threshold value, the mixing ratio of the leachate is decreased; Alternatively, the change of the moisture content of the garbage slurry after the extrusion dewatering is determined by the current value of the extrusion dewatering device, if the current value of the extrusion dewatering device is higher than the preset threshold value, the mixing ratio of the leachate is increased, and if the current value of the extrusion dewatering device is lower than the preset threshold value, the mixing ratio of the leachate is decreased.

2. The method of claim 1, wherein the method is optimized for extracting oil and fat from food waste. In step S22, the preset mixing ratio of the kitchen garbage and the leachate is 2:1, and in step S24, the mixing ratio of the kitchen garbage and the leachate is adjusted within the range of 4:3 to 8:

3.

3. The method of claim 1, wherein the method is optimized for extracting oil and fat from food waste. The preset threshold value of the hydraulic pressure value of the plunger pump is 15-17 Mpa.

4. The method of claim 1, wherein the method is optimized for extracting oil and fat from food waste. The preset threshold value of the current value of the extrusion dewatering device is 15-20 A.

5. A kitchen waste oil and fat extraction optimization system, characterized in that, The kitchen garbage pretreatment module and the oil extraction device are included, the kitchen garbage pretreatment module pretreats the kitchen garbage through the steps of the method according to any one of claims 1-4, and the oil extraction device extracts oil from the pretreated kitchen garbage.

6. The kitchen waste grease extraction optimization system of claim 5, wherein, The kitchen garbage pretreatment module further comprises a garbage collection device, a receiving hopper, a leachate storage device, a leachate lifting pump, a crushing device, a plunger pump and an extrusion dewatering device, the kitchen garbage to be pretreated is placed in the garbage collection device, the receiving hopper receives the kitchen garbage in the garbage collection device and transports it to the crushing device, the leachate storage device collects the leachate seeped out from the kitchen garbage in sequence through the garbage collection device and the receiving hopper, the leachate lifting pump pumps the leachate in the leachate storage device into the crushing device to mix with the kitchen garbage, the crushing device performs the large material sorting treatment on the kitchen garbage to obtain the garbage slurry, the plunger pump pumps the garbage slurry into the extrusion dewatering device, and the extrusion dewatering device performs the extrusion dewatering treatment on the garbage slurry.

7. The kitchen waste grease extraction optimization system of claim 6, wherein, The control device controls the amount of sap output by the sap lifting pump according to the hydraulic pressure value fed back by the plunger pump and the current value fed back by the extrusion dewatering device, so as to control the mixing ratio of the sap and the kitchen garbage.

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