Device and method for enhancing hydrothermal carbonization of organic waste through plant ash coupling granulation

Abstract

The invention belongs to the technical field of organic waste treatment, and discloses a device and method for strengthening hydrothermal carbonization of organic waste through plant ash coupling granulation, organic waste is subjected to vibration fluidization through a vibration fluidization device, and the organic waste is subjected to multi-stage cutting and stirring through three layers of spiral blade paddles; the multi-stage mechanical granulation of the organic waste is realized under the combined action of the two, and the macrostructure of the organic waste is destroyed and modified, so that the organic waste becomes uniform small-particle organic waste; then, alkaline plant ash is used for promoting biomass molecules of the uniform small-particle organic waste to be subjected to alkaline deconstruction, the microstructure of the organic waste is destroyed and modified, and the hydrothermal activity is improved.

Description

Technical Field

[0001] This application belongs to the technical field of organic waste treatment, and particularly relates to a device and method for enhancing hydrothermal carbonization of organic waste by coupling with wood ash granulation. Background Technique

[0002] In China, the output of multi-source organic wastes such as excess sludge, garden green waste, and fruit and vegetable waste is huge, and their resource-based disposal is one of the core contents of building a green and resource-saving city. At present, the traditional resource-consuming organic waste disposal mode is transforming towards a resource-recycling type. Compared with traditional resource-based disposal methods such as anaerobic digestion, anaerobic fermentation, aerobic composting, and high-temperature pyrolysis, carbonization technology has the advantages of short treatment cycle, high recovery rate of carbon materials, full consumption and treatment of organic waste, no residue discharge, etc., and can recover high-quality carbon particles, which can be used as high-quality carbon sequestration materials for soil improvement and restoration.

[0003] At present, carbonization technology mainly includes two categories: pyrolytic carbonization and hydrothermal carbonization. Pyrolytic carbonization requires drying the organic waste, using an inert gas as the pyrolysis reaction medium, and converting the organic waste into biochar under anaerobic conditions using high temperature (300 - 800 °C). Hydrothermal carbonization technology does not require drying, uses the moisture in the organic waste as the reaction medium, does not need to control anaerobic conditions, and uses a relatively low temperature (170 - 300 °C) to convert the organic waste into hydrothermal carbon through hydrolysis, dehydration, decarboxylation, polymerization, and aromatization, and obtains solid-phase hydrothermal carbon particles and liquid-phase hydrothermal carbon products. Compared with traditional pyrolytic carbonization, hydrothermal carbonization is a very promising organic waste resource-based technology, with the advantages of no need for pre-drying, no need to control anaerobic conditions, lower reaction temperature and pressure, lower energy consumption and cost, and remarkable benefits.

[0004] However, current hydrothermal carbonization technology still has problems in the disposal of organic waste, such as high thermodynamic barriers in the hydrothermal reaction, poor mass transfer efficiency, and low hydrothermal efficiency. Moreover, the uncontrolled traditional hydrothermal reaction direction leads to the residue of by-products and poor quality of hydrochar, restricting the recycling prospect of hydrochar products. The fundamental reason lies in the stable molecular configuration and poor catalytic activity of the biomass in organic waste. The macroscopic structure of organic waste has characteristics such as large particle size, small specific surface area, and low porosity, which limit the mass transfer efficiency of hydrothermal conversion. At the same time, the microscopic biomass structure of organic waste is stable, with poor hydrophilicity, low hydrothermal activity, and poor modification of the biomass structure, resulting in low hydrothermal conversion efficiency and greatly restricting the reaction process of hydrothermal carbonization. The by-products of hydrothermal carbonization are also one of the main bottlenecks restricting the effectiveness of this technology. Traditional hydrothermal carbonization processes are prone to generating by-products such as tar, and volatile fatty acids, the intermediate products, will also damage the structure of hydrochar products under high-temperature conditions, leading to a decrease in carbon yield. Current research mainly improves the hydrothermal carbonization efficiency and inhibits the generation of by-products by optimizing technical parameters such as hydrothermal temperature, hydrothermal pressure, reaction time, and solid-liquid ratio, or modifies hydrochar products through physical or chemical modification methods to improve the quality of hydrochar products. There are few studies on developing enhanced hydrothermal carbonization technologies from the perspective of regulating the macroscopic and microscopic structures of organic waste. Moreover, current enhanced hydrothermal carbonization technologies require a large amount of energy or chemical consumption, restricting economic benefits. In addition, although the hydrochar products recovered after the hydrothermal carbonization treatment of current organic waste have rich carbon, nitrogen, and phosphorus elements and meet the requirements of soil conditioners, they still lack potassium, an essential element for plant growth. If potassium can be supplemented during the hydrothermal carbonization process of organic waste, the nutrient element composition distribution of hydrochar products can be further enriched, and the quality of soil conditioners can be improved.

[0005] In summary, considering the perspective of treating waste with waste, using waste as an enhancement measure to develop a technology for simultaneously modifying the macroscopic and microscopic structures of organic waste, thereby improving the hydrothermal activity and contact mass transfer efficiency of organic waste, catalyzing the hydrothermal reaction, enhancing the hydrothermal carbonization efficiency, while inhibiting the generation of by-products and supplementing potassium, is an urgent current technical requirement, and there is no relevant technology yet. Summary of the Invention

[0006] The purpose of this application is to solve the problems of the prior art and provide a device and method for enhancing the fermentation of organic waste to extract a fermentation broth with a high carbon-nitrogen ratio.

[0007] To solve the technical problems, the technical solution of this application is: a method for enhancing the hydrothermal carbonization of organic waste by coupling with wood ash granulation, comprising the following steps: S1: Dehydrate or dilute the organic waste with water to adjust the moisture content of the organic waste to 80 - 90%, obtaining the organic waste A with adjusted moisture content; S2: putting the organic waste A into the macro / micro structure modification reactor, using a multi-stage cutting stirrer to cut and stir the organic waste A at a low speed, preliminarily breaking the structure of the organic waste A, and obtaining an uneven block organic waste B; S3: using a vibration fluidization device to perform high-frequency vibration fluidization on the organic waste B, and using a multi-stage cutting and stirring device to perform high-speed cutting and stirring on the organic waste B, so that the organic waste B is converted into a uniform small particle form through the combined action of high-frequency vibration fluidization and high-speed cutting and stirring, thereby modifying the macro structure of the organic waste B to obtain organic waste C in a uniform small particle form; S4: adding alkaline wood ash to the macro / micro structure modification reactor, wherein the amount of alkaline wood ash added is 0.25-1.25 g / g TS of organic waste C, and performing low-speed cutting and stirring. At the same time, a vibration fluidization device is used to perform low-frequency vibration fluidization on the organic waste C and the alkaline wood ash, and the alkaline wood ash is used to promote alkaline deconstruction of the organic waste C, and the microstructure of the organic waste C is modified to obtain a mixture D of the organic waste C and the alkaline wood ash, wherein the pH of the mixture D is 8.0-10.5; S5: adding the mixture D into the hydrothermal reactor, performing a hydrothermal reaction at a temperature of 160-230° C. for 25-100 min, and stirring the mixture D at a speed of 20-100 rpm. During this process, the hydrothermal reactor is strictly closed to maintain a saturated vapor pressure environment, completing the hydrothermal carbonization reaction, and obtaining a hydrothermal carbonization mixed product E; S6: adding the hydrothermal carbonization mixed product E into a suspended percolation tank for solid-liquid separation to obtain hydrothermal carbon particles and hydrothermal liquid respectively; S7: Detect the moisture content of the hydrothermal carbon particles. If the moisture content is ≤40%, proceed to the next step. If the moisture content is >40%, repeat S6 until the moisture content is ≤40%. S8: collecting the hydrothermal carbon particles and putting them into a cleaning tank to complete the cleaning of the hydrothermal carbon particles, and then discharging the cleaning water from the cleaning water outlet at the bottom of the cleaning tank, while using a filter screen provided at the cleaning water outlet to intercept the hydrothermal carbon particles; S9: Collect the washed hydrothermal carbon particles, lay them flat outdoors, and air-dry them for 6 to 24 hours under sunlight to obtain dry hydrothermal carbon particles. Detect the carbon, nitrogen, phosphorus, and potassium element ratios and specific capacitance indicators of the hydrothermal carbon particles. If they are qualified, collect them for use as soil conditioners. S10: Collect hydrothermal fluid from the bottom of the suspended infiltration tank and discharge it into the sewage treatment system as a supplementary carbon source.

[0008] Preferably, the organic waste in S1 is one or more of dewatered sludge, fruit and vegetable waste, and gardening waste; When the moisture content of the organic waste is < 80%, add clear water to the organic waste to adjust the moisture content of the organic waste to 80 - 90%; when the moisture content of the organic waste is > 90%, dehydrate the organic waste to adjust the moisture content of the organic waste to 80 - 90%; when the moisture content of the organic waste is 80 - 90%, the S1 step is not required; In S2, use a multi-stage cutting stirrer to perform low-speed cutting and stirring on the organic waste A for 1 - 5 minutes, and set the rotation speed to 100 - 250 rpm.

[0009] Preferably, in S3, use a vibration fluidization device to perform high-frequency vibration fluidization on the organic waste B, with a vibration frequency of 200 - 700 r / min, and use a multi-stage cutting stirrer to perform high-speed cutting and stirring on the organic waste B for 5 - 20 minutes, and set the rotation speed to 250 - 700 rpm; When the organic waste is dewatered sludge, set the rotation speed of the multi-stage cutting stirrer to 250 - 350 rpm, perform high-speed cutting and stirring on the organic waste B for 5 - 15 minutes, and the average particle size of the obtained organic waste C is 3 - 20 mm; When the organic waste is fruit and vegetable waste, set the rotation speed of the multi-stage cutting stirrer to 350 - 500 rpm, perform high-speed cutting and stirring on the organic waste B for 5 - 20 minutes, and the average particle size of the obtained organic waste C is 1 - 15 mm; When the organic waste is garden greening waste, set the rotation speed of the multi-stage cutting stirrer to 500 - 700 rpm, perform high-speed cutting and stirring on the organic waste B for 10 - 20 minutes, and the average particle size of the obtained organic waste C is 1 - 15 mm.

[0010] Preferably, the pH of the alkaline plant ash used in S4 is 10.5 - 12, and the soluble K element content ≥ 7%; add the alkaline plant ash to the macro / micro structure modification reactor, stir at a rotation speed of 50 - 150 rpm for 1 - 3 minutes, and at the same time use a vibration fluidization device to perform low-frequency vibration fluidization on the organic waste C and the alkaline plant ash, with a vibration frequency of 100 - 450 r / min.

[0011] Preferably, add alkaline plant ash in S4 and mix it with the organic waste C to obtain a mixture D. By regulating the dosage of the alkaline plant ash, ensure that the pH of the mixture D is 8.0 - 10.5; When the organic waste is dewatered sludge, the pH of the mixture D is 9.0 - 10.5; When the organic waste is fruit and vegetable waste, the pH of the mixture D is 8.5 - 10.0; When the organic waste is garden greening waste, the pH of the mixture D is 8.0 - 9.5.

[0012] Preferably, in step S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160 - 200 °C and the hydrothermal time is 25 - 50 min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200 - 230 °C and the hydrothermal time is 40 - 100 min; when the organic waste is garden greening waste, the hydrothermal temperature is 200 - 230 °C and the hydrothermal time is 40 - 100 min. In step S6, the hydrothermal carbonization mixture E is added into a suspended percolation tank. A suspended filter cloth is arranged on the upper layer of the suspended percolation tank. The hydrothermal carbonization mixture E is evenly spread on the surface of the suspended filter cloth by a cloth plate and left to stand for 1 - 12 h to achieve gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth is the hydrothermal carbon particles, and the liquid that percolates from the suspended filter cloth into the suspended percolation tank is the hydrothermal liquid.

[0013] Preferably, in step S8, the hydrothermal carbon particles are put into a cleaning tank and stirred at a rotation speed of 100 - 300 rpm for 0.5 - 2 h, and the cleaning is repeated 1 - 5 times. When the organic waste is dewatered sludge, the hydrothermal carbon particles are cleaned 3 - 5 times. When the organic waste is fruit and vegetable waste, the hydrothermal carbon particles are cleaned 2 - 4 times. When the organic waste is garden greening waste, the hydrothermal carbon particles are cleaned 1 - 3 times.

[0014] Preferably, the dried hydrothermal carbon particles in step S9 are detected. The hydrothermal carbon yield of dewatered sludge is ≥ 50%, the hydrothermal carbon yield of fruit and vegetable waste is ≥ 30%, and the hydrothermal carbon yield of garden greening waste is ≥ 60%. The carbon element content of the hydrothermal carbon of dewatered sludge is ≥ 30%, the carbon element content of the hydrothermal carbon of fruit and vegetable waste is ≥ 55%, and the carbon element content of the hydrothermal carbon of garden greening waste is ≥ 60%. The phosphorus element content of the hydrothermal carbon of dewatered sludge is ≥ 3%, the phosphorus element content of the hydrothermal carbon of fruit and vegetable waste is ≥ 0.15%, and the phosphorus element content of the hydrothermal carbon of garden greening waste is ≥ 0.2%. The potassium element content of the hydrothermal carbon of dewatered sludge is ≥ 2%, the potassium element content of the hydrothermal carbon of fruit and vegetable waste is ≥ 2.5%, and the potassium element content of the hydrothermal carbon of garden greening waste is ≥ 1%. The specific capacitance of the hydrothermal carbon of dewatered sludge is ≥ 1.8 F / g, the specific capacitance of the hydrothermal carbon of fruit and vegetable waste is ≥ 6.5 F / g, and the specific capacitance of the hydrothermal carbon of garden greening waste is ≥ 5 F / g.

[0015] Preferably, a device for enhancing hydrothermal carbonization of organic waste by coupling with plant ash granulation is used for implementing the above method for enhancing hydrothermal carbonization of organic waste by coupling with plant ash granulation, and includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended filtration module, a hydrothermal carbon particle cleaning module, a detection module and a control component. The moisture content adjustment module, the macro / micro structure modification module, the hydrothermal carbonization reaction module, the suspended filtration module, the hydrothermal carbon particle cleaning module and the detection module are respectively electrically connected to the control component; The moisture content adjustment module includes a moisture content adjustment tank and a dehydrator. The moisture content adjustment tank is provided with a first organic waste feeding port, a water adding port, a first stirring device and a first discharge port. The water adding port is connected to a water tank, and the dehydrator is also provided with a first discharge port; The macro / micro structure modification module includes a first screw feeder and a macro / micro structure modification reactor. The macro / micro structure modification reactor is internally provided with a multi-stage cutting stirrer and a vibration fluidization device. The macro / micro structure modification reactor is also provided with a second organic waste feeding port, an alkaline plant ash feeding port and a second discharge port. The vibration fluidization device is arranged at the bottom of the macro / micro structure modification reactor, and a solid metering feeding device is arranged at the top of the alkaline plant ash feeding port. The bottom of the first screw feeder is connected to the first discharge port, and the top of the first screw feeder is connected to the second organic waste feeding port; The hydrothermal carbonization reaction module includes a second screw feeder and a hydrothermal reaction kettle. The hydrothermal reaction kettle is internally provided with a second stirring device and a heating and temperature control device. The hydrothermal reaction kettle is also provided with a mixture feeding port, a pressure monitoring device, a third discharge port, a pressure relief valve and an explosion-proof sheet. The bottom of the second screw feeder is connected to the second discharge port, and the top of the second screw feeder is connected to the mixture feeding port; The suspended filtration module includes a feed pump and a suspended filtration tank. An upper filter cloth support is arranged in the suspended filtration tank, and a suspended filter cloth is placed on the upper filter cloth support. A cloth plate is arranged on the surface of the suspended filter cloth, and the cloth plate is connected to a mechanical transmission machine. A hydrothermal liquid collecting hopper, a hydrothermal liquid discharge pipe and a valve are arranged at the bottom of the suspended filtration tank. One end of the feed pump is connected to the third discharge port, and the other end is connected to the top of the suspended filter cloth; The hydrothermal carbon particle cleaning module includes a cleaning water storage tank and a cleaning pool. A third stirring device is arranged in the cleaning pool, and a filter screen and a cleaning water discharge port are arranged at the bottom of the cleaning pool. The cleaning water storage tank is connected to the cleaning pool; The detection module includes a moisture content detector, an element analyzer, a capacitance tester and a pH meter. The moisture content detector is used for detecting the moisture content of the organic waste A at the first discharge port and the hydrothermal carbon particles on the suspended filter cloth; The pH meter is used for detecting the pH of the mixture D at the second discharge port; The moisture content detector, the element analyzer, the capacitance tester and the pH meter are also used for detecting the property indexes of the hydrothermal carbon particles at the filter screen.

[0016] Preferably, the macro / micro structure modification reactor is a cylindrical barrel reactor, and the ratio of the diameter to the height is 1:3 to 5:1. The multi-stage cutting stirrer is equipped with three layers of spiral blade impellers, and the distance between each layer of spiral blade impellers is 1 / 7 to 1 / 4 of the height of the macro / micro structure modification reactor. The spiral blade impellers are distributed blades made of stainless steel. The first and third layers of spiral blade impellers are three-blade impellers arranged at an interval of 120°, and the blades are twisted by 35° to 55°. The second layer of spiral blade impellers is six-blade impellers arranged at an interval of 60°, and the blades are twisted by 25° to 45°. The lengths of the spiral blade impellers are all 1 / 4 to 2 / 5 of the inner diameter of the macro / micro structure modification reactor. The mesh number of the suspended filter cloth is ≥200 meshes, and the pore diameter of the filter screen is ≤0.1 mm.

[0017] Compared with the prior art, the advantages of this application are as follows: (1) This application uses multi-stage cutting stirring and vibration fluidization to jointly perform macro mechanical granulation on organic waste. While performing multi-stage cutting stirring, using the vibration fluidization effect of 200 - 700 r / min can maximize the conversion efficiency of the macro structure modification of organic waste. The vibration fluidization effect can make the organic waste particles present a vibration motion and a semi-fluidized state in the macro / micro structure modification reactor, providing better contact collision and cutting granulation conditions for cutting stirring, and can efficiently realize the mechanical granulation function. Different from the disordered crushing process of the macro structure of organic waste in the traditional crushing method, the joint treatment of multi-stage cutting stirring and vibration fluidization used in this application is an ordered crushing and granulation process of the macro structure of organic waste. What is obtained is not the irregular large organic waste fragments produced by the traditional crushing method, but small particle organic waste particles with uniform particle size and regular shape. The small particle organic waste obtained has the advantages of smaller particle size, more uniform particle size distribution, higher particle dispersion degree, and larger specific surface area. It has high hydrothermal mass transfer efficiency and uniform mass transfer in the subsequent hydrothermal carbonization treatment link, which helps to reduce the reaction temperature, reaction time, and reaction pressure of hydrothermal carbonization, and improve the hydrothermal carbon yield and the physical and chemical structure properties of hydrothermal carbon particles. (2) This application uses alkaline plant ash for biomass micro-structure modification treatment. Alkaline plant ash can play a long-term, continuous and stable alkaline deconstruction role, perform alkaline pre-deconstruction on the difficult-to-degrade and difficult-to-convert organic matter in organic waste, improve its hydrothermal reaction activity, reduce the reaction energy barrier of hydrothermal carbonization, which helps to reduce the reaction temperature, reaction time, and reaction pressure of hydrothermal carbonization, and improve the hydrothermal carbon yield and the physical and chemical structure properties of hydrothermal carbon particles. (3) The present application uses a multi-stage cutting agitator to preliminarily crush the organic waste at a low speed of 100-250 rpm, and the organic waste is preliminarily crushed into an uneven block shape; then the cutting and crushing is performed at a high speed of 250-700 rpm for 5-20 minutes to further convert the organic waste into a uniform small particle form, and alkaline wood ash is added to the uniform small particle organic waste, and stirred at a low speed of 50-150 rpm for 1-3 minutes, and vibrating fluidization is performed at the same time to improve the mixing uniformity of the uniform small particle organic waste and the alkaline wood ash; the multi-stage treatment process of low-speed crushing-high-speed cutting / vibrating fluidization-low-speed mixing / vibrating fluidization in the present application can effectively improve the macro-structure modification effect (improving granulation efficiency, particle uniformity and dispersion degree) and micro-structure modification effect (reducing molecular helical tightness and improving hydrothermal reaction activity) of organic waste, and combined with the speed and time design of the multi-stage treatment process, it can play the best macro- / micro-structure modification effect of organic waste; (4) The present application utilizes alkaline wood ash coupled with multi-stage mechanical granulation to simultaneously modify and transform the macrostructure and microstructure of organic waste, which can play a synergistic role, improve the reaction mass transfer efficiency and the hydrothermal activity of biomass, thereby improving the hydrothermal carbonization efficiency of organic waste, and significantly shortening the overall reaction time; at the same time, after the alkaline wood ash coupled with multi-stage mechanical granulation treatment, the macro / microstructure modification and transformation of organic waste accelerates and enhances the hydrothermal process, making it easier for the hydrothermal reaction to fully occur, and the hydrothermal carbonization can be completed at only 160-230°C. The reaction temperature is low, and the saturated vapor pressure is also low, the reaction conditions are mild, and the engineering difficulty is reduced; in addition, after the alkaline wood ash is coupled with multi-stage mechanical granulation treatment, the hydrothermal carbon particles recovered after the organic waste hydrothermal carbonization treatment are of good quality, the surface morphology such as porous structure and surface area is greatly improved, the degree of fragmentation and porosity are increased, the aromatic structure and oxygen-containing functional groups are improved, the surface structure and chemical / electrochemical properties are excellent, the carbonization rate is higher, the content of nutrients such as carbon, phosphorus and potassium is higher, the specific capacitance is higher, and the electrochemical properties are better; (5) The alkaline wood ash used in this application is rich in potassium, which can supplement potassium on the basis of the rich carbon, nitrogen and phosphorus elements in the hydrochar products of organic waste, improve and enrich the nutrient element composition distribution of the hydrochar products, and transform them into high-quality soil conditioners with coexistence of carbon fertilizer, nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer. The potassium content of the obtained hydrochar products is significantly higher than that of the hydrochar or biochar obtained by traditional technology, which can improve the soil remediation effect of the hydrochar products; (6) This application uses a self-designed multi-stage cutting agitator to conduct macrostructural modification and transformation of organic waste. Three layers of spiral blade impellers are installed, and the spacing between each layer of spiral blade impellers is 1 / 7 - 1 / 4 of the effective height of the macro / microstructural modification reactor. The first and third layers of spiral blade impellers are three-blade impellers arranged at intervals of 120°, and the blades of the impellers are twisted by 35° - 55°. The second layer of spiral blade impellers is six-blade impellers arranged at intervals of 60°, and the blades are twisted by 25° - 45°. The length of the blade impellers is 1 / 4 - 2 / 5 of the effective inner diameter of the macro / microstructural modification reactor. The design of the blade arrangement levels, the number of blades in each layer, the arrangement angle, and the twisting angle of the spiral blade impellers in this application can improve the modification and transformation efficiency of the macrostructure of organic waste. Compared with traditional crushing methods, the particle size of the organic waste after macrostructural modification and transformation using the multi-stage cutting agitator in this application is smaller. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a device for enhancing hydrothermal carbonization of organic waste by coupling with plant ash granulation in this application; Figure 2 are the product properties of the sludge hydrothermal carbon in Application Example 1 of this application; Figure 3 are the product properties of the hydrothermal carbon of garden greening waste in Application Example 2 of this application; Figure 4 are the product properties of the hydrothermal carbon of fruit and vegetable waste in Application Example 3 of this application; Figure 5 is a process flow chart of a method for enhancing hydrothermal carbonization of organic waste by coupling with plant ash granulation in this application.

[0019] Description of the Reference Numerals: 1 - Moisture content adjustment tank; 2 - First organic waste feeding port; 3 - Water adding port; 4 - Water tank; 5 - First stirring device; 6 - First discharging port; 7 - Dehydrator; 8 - First screw feeder; 9 - Macro / micro structure modification reactor; 10 - Multi-stage cutting stirrer; 11 - Vibrating fluidization device; 12 - Second organic waste feeding port; 13 - Solid metering feeding device; 14 - Alkaline plant ash feeding port; 15 - Second discharging port; 16 - Second screw feeder; 17 - Hydrothermal reaction kettle; 18 - Second stirring device; 19 - Heating and temperature control device; 20 - Mixture feeding port; 21 - Pressure monitoring device; 22 - Third discharging port; 23 - Pressure relief valve and explosion-proof sheet; 24 - Feed pump; 25 - Suspended percolation tank; 26 - Upper filter cloth support; 27 - Suspended filter cloth; 28 - Cloth distributing plate; 29 - Mechanical transmission; 30 - Hydrothermal liquid collecting hopper; 31 - Hydrothermal liquid discharge pipe and valve; 32 - Cleaning tank; 33 - Third stirring device; 34 - Filter screen; 35 - Cleaning water discharge port; 36 - Cleaning water storage tank; 37 - Moisture content detector; 38 - Element analyzer; 39 - Capacitance tester; 40 - pH meter. Detailed implementation mode

[0020] The following describes the present application in detail with reference to the accompanying drawings and specific embodiments, but the present application is not limited to these embodiments. The present application covers any alternatives, modifications, equivalent methods and solutions made within the essence and scope of the present application. In order to enable the public to have a thorough understanding of the present application, specific details are described in detail in the following embodiments of the present application, and those skilled in the art can fully understand the present application without the description of these details.

[0021] As Figure 1 、 5 shown, the present application discloses a method for coupling granulation of plant ash to strengthen hydrothermal carbonization of organic waste, including the following steps: S1: Dehydrate the organic waste or dilute it with water to adjust the moisture content of the organic waste to 80 - 90%, and obtain the organic waste A with adjusted moisture content. S2: Put the organic waste A into the macro / micro structure modification reactor 9, and use the multi-stage cutting stirrer 10 to cut and stir the organic waste A at a low speed to preliminarily break the structure of the organic waste A and obtain the uneven blocky organic waste B. S3: Use the vibrating fluidization device 11 to perform high-frequency vibrating fluidization on the organic waste B, and at the same time use the multi-stage cutting stirrer 10 to cut and stir the organic waste B at a high speed. Through the combined action of high-frequency vibrating fluidization and high-speed cutting and stirring, the organic waste B is transformed into a uniform small particle form, thereby modifying the macro structure of the organic waste B to obtain the organic waste C in a uniform small particle form. S4: Add alkaline plant ash to the macro / microstructure modification reactor 9. The dosage of alkaline plant ash is 0.25 - 1.25 g / g of TS organic waste C. Stir, and at the same time, use the vibration fluidization device 11 to perform low-frequency vibration fluidization on the organic waste C and alkaline plant ash, and use the alkaline plant ash to promote the alkaline deconstruction of the organic waste C, modify the microstructure of the organic waste C, and obtain a mixture D of the organic waste C and alkaline plant ash. The pH of the mixture D is 8.0 - 10.5; S5: Add the mixture D to the hydrothermal reaction kettle 17, and carry out hydrothermal reaction at a temperature of 160 - 230 °C for 25 - 100 min. At the same time, stir the mixture D at a rotation speed of 20 - 100 rpm. During this process, the hydrothermal reaction kettle 17 is strictly closed to maintain a saturated steam pressure environment, complete the hydrothermal carbonization reaction, and obtain a hydrothermal carbonization mixed product E; S6: Add the hydrothermal carbonization mixed product E to the suspended percolation tank 25 for solid-liquid separation to obtain hydrothermal carbon particles and hydrothermal liquid respectively; S7: Detect the moisture content of the hydrothermal carbon particles. If the moisture content ≤ 40%, proceed to the next step. If the moisture content > 40%, repeat S6 until the moisture content ≤ 40%; S8: Collect the hydrothermal carbon particles, put them into the cleaning tank 32 to complete the cleaning of the hydrothermal carbon particles, then discharge the cleaning water from the cleaning water discharge port 35 at the bottom of the cleaning tank 32, and at the same time, use the filter screen 34 set at the cleaning water discharge port 35 to intercept the hydrothermal carbon particles; S9: Collect the cleaned hydrothermal carbon particles, spread them out outdoors, and air-dry them under sunlight for 6 - 24 h to obtain dry hydrothermal carbon particles. Detect the carbon, nitrogen, phosphorus, and potassium element ratios and specific capacitance indexes of the hydrothermal carbon particles. After passing the inspection, collect them for use as a soil conditioner; S10: Collect the hydrothermal liquid from the bottom of the suspended percolation tank 25 and discharge it into the sewage treatment system as a supplementary carbon source.

[0022] Preferably, the organic waste in S1 is one or more of dehydrated sludge, fruit and vegetable waste, and garden greening waste; When the moisture content of the organic waste < 80%, add clean water to the organic waste to adjust the moisture content of the organic waste to 80 - 90%. When the moisture content of the organic waste > 90%, dehydrate the organic waste to adjust the moisture content of the organic waste to 80 - 90%. When the moisture content of the organic waste is 80 - 90%, the S1 step is not required; In S2, use the multi-stage cutting stirrer 10 to perform low-speed cutting and stirring on the organic waste A for 1 - 5 min, and set the rotation speed to 100 - 250 rpm.

[0023] Preferably, in step S3, the organic waste B is subjected to high-frequency vibration fluidization by the vibration fluidization device 11 at a vibration frequency of 200 - 700 r / min, and the organic waste B is subjected to high-speed cutting and stirring for 5 - 20 min by the multi-stage cutting stirrer 10 with the rotation speed set at 250 - 700 rpm; When the organic waste is dewatered sludge, the rotation speed of the multi-stage cutting stirrer 10 is set at 250 - 350 rpm, and the organic waste B is subjected to high-speed cutting and stirring for 5 - 15 min, and the average particle size of the obtained organic waste C is 3 - 20 mm; When the organic waste is fruit and vegetable waste, the rotation speed of the multi-stage cutting stirrer 10 is set at 350 - 500 rpm, and the organic waste B is subjected to high-speed cutting and stirring for 5 - 20 min, and the average particle size of the obtained organic waste C is 1 - 15 mm; When the organic waste is garden greening waste, the rotation speed of the multi-stage cutting stirrer 10 is set at 500 - 700 rpm, and the organic waste B is subjected to high-speed cutting and stirring for 10 - 20 min, and the average particle size of the obtained organic waste C is 1 - 15 mm.

[0024] Preferably, the pH of the alkaline plant ash used in step S4 is 10.5 - 12, and the soluble K element content is ≥7%; the alkaline plant ash is added to the macro / micro structure modification reactor 9 and stirred at a rotation speed of 50 - 150 rpm for 1 - 3 min, and at the same time, the organic waste C and the alkaline plant ash are subjected to low-frequency vibration fluidization by the vibration fluidization device 11 at a vibration frequency of 100 - 450 r / min.

[0025] Preferably, in step S4, the alkaline plant ash is added to the organic waste C to obtain a mixture D, and by adjusting the dosage of the alkaline plant ash, the pH of the mixture D is ensured to be 8.0 - 10.5; When the organic waste is dewatered sludge, the pH of the mixture D is 9.0 - 10.5; When the organic waste is fruit and vegetable waste, the pH of the mixture D is 8.5 - 10.0; When the organic waste is garden greening waste, the pH of the mixture D is 8.0 - 9.5.

[0026] Preferably, in step S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160 - 200 °C and the hydrothermal time is 25 - 50 min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200 - 230 °C and the hydrothermal time is 40 - 100 min; when the organic waste is garden greening waste, the hydrothermal temperature is 200 - 230 °C and the hydrothermal time is 40 - 100 min; In step S6, the hydrothermal carbonization mixture E is added to the suspended percolation tank 25. A suspended filter cloth 27 is arranged on the upper layer of the suspended percolation tank 25. The hydrothermal carbonization mixture E is evenly spread on the surface of the suspended filter cloth 27 by using the cloth plate 28 and left standing for 1 to 12 hours to achieve gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth 27 is the hydrochar particles, and the liquid that percolates from the suspended filter cloth 27 into the suspended percolation tank 25 is the hydrothermal liquid.

[0027] Preferably, in step S8, the hydrochar particles are put into the cleaning tank 32 and stirred at a rotation speed of 100 to 300 rpm for 0.5 to 2 hours, and the cleaning is repeated 1 to 5 times; When the organic waste is dewatered sludge, the hydrochar particles are cleaned 3 to 5 times; When the organic waste is fruit and vegetable waste, the hydrochar particles are cleaned 2 to 4 times; When the organic waste is garden greening waste, the hydrochar particles are cleaned 1 to 3 times.

[0028] Preferably, the dried hydrochar particles in step S9 are detected. The hydrochar yield of dewatered sludge is ≥50%, the hydrochar yield of fruit and vegetable waste is ≥30%, and the hydrochar yield of garden greening waste is ≥60%; The carbon element content of the hydrochar of dewatered sludge is ≥30%, the carbon element content of the hydrochar of fruit and vegetable waste is ≥55%, and the carbon element content of the hydrochar of garden greening waste is ≥60%; The phosphorus element content of the hydrochar of dewatered sludge is ≥3%, the phosphorus element content of the hydrochar of fruit and vegetable waste is ≥0.15%, and the phosphorus element content of the hydrochar of garden greening waste is ≥0.2%; The potassium element content of the hydrochar of dewatered sludge is ≥2%, the potassium element content of the hydrochar of fruit and vegetable waste is ≥2.5%, and the potassium element content of the hydrochar of garden greening waste is ≥1%; The specific capacitance of the hydrochar of dewatered sludge is ≥1.8 F / g, the specific capacitance of the hydrochar of fruit and vegetable waste is ≥6.5 F / g, and the specific capacitance of the hydrochar of garden greening waste is ≥5 F / g.

[0029] Preferably, a device for coupling and granulating plant ash to strengthen the hydrothermal carbonization of organic waste is used to implement the above-mentioned method for coupling and granulating plant ash to strengthen the hydrothermal carbonization of organic waste, and includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended percolation module, a hydrochar particle cleaning module, a detection module and a control component. The moisture content adjustment module, the macro / micro structure modification module, the hydrothermal carbonization reaction module, the suspended percolation module, the hydrochar particle cleaning module and the detection module are respectively electrically connected to the control component; The moisture content adjustment module includes a moisture content adjustment tank 1 and a dehydrator 7. The moisture content adjustment tank 1 is provided with a first organic waste feeding port 2, a water adding port 3, a first stirring device 5 and a first discharge port 6. The water adding port 3 is connected to a water tank 4. The dehydrator 7 is also provided with a first discharge port 6; The macro / micro structure modification module includes a first screw feeder 8 and a macro / micro structure modification reactor 9. The macro / micro structure modification reactor 9 is internally provided with a multi-stage cutting stirrer 10 and a vibration fluidization device 11. The macro / micro structure modification reactor 9 is also provided with a second organic waste feeding port 12, an alkaline plant ash feeding port 14 and a second discharge port 15. The vibration fluidization device 11 is arranged at the bottom of the macro / micro structure modification reactor 9. A solid metering feeding device 13 is arranged at the top of the alkaline plant ash feeding port 14. The bottom of the first screw feeder 8 is connected to the first discharge port 6, and the top of the first screw feeder 8 is connected to the second organic waste feeding port 12; The hydrothermal carbonization reaction module includes a second screw feeder 16 and a hydrothermal reaction kettle 17. The hydrothermal reaction kettle 17 is internally provided with a second stirring device 18 and a heating and temperature control device 19. The hydrothermal reaction kettle 17 is also provided with a mixture feeding port 20, a pressure monitoring device 21, a third discharge port 22 and a pressure relief valve and explosion-proof sheet 23. The bottom of the second screw feeder 16 is connected to the second discharge port 15, and the top of the second screw feeder 16 is connected to the mixture feeding port 20; The suspended filtration module includes a feed pump 24 and a suspended filtration tank 25. An upper filter cloth support 26 is arranged in the suspended filtration tank 25. A suspended filter cloth 27 is placed on the upper filter cloth support 26. A cloth distributing plate 28 is arranged on the surface of the suspended filter cloth 27. The cloth distributing plate 28 is connected to a mechanical transmission device 29. A hydrothermal liquid collecting hopper 30 and a hydrothermal liquid discharge pipe and valve 31 are arranged at the bottom of the suspended filtration tank 25. One end of the feed pump 24 is connected to the third discharge port 22, and the other end is connected to the top of the suspended filter cloth 27; The hydrothermal carbon particle cleaning module includes a cleaning water storage tank 36 and a cleaning tank 32. The cleaning tank 32 is internally provided with a third stirring device 33. A filter screen 34 and a cleaning water discharge port 35 are arranged at the bottom of the cleaning tank 32. The cleaning water storage tank 36 is connected to the cleaning tank 32; The detection module includes a moisture content detector 37, an element analyzer 38, a capacitance tester 39 and a pH meter 40. The moisture content detector 37 is used to detect the moisture content of the organic waste A at the first discharge port 6 and the hydrothermal carbon particles on the suspended filter cloth 27; The pH meter 40 is used to detect the pH of the mixture D at the second discharge port 15; The moisture content detector 37, the element analyzer 38, the capacitance tester 39 and the pH meter 40 are also used to detect the property indexes of the hydrothermal carbon particles at the filter screen 34.

[0030] Preferably, the macro / micro structure modification reactor 9 is a cylindrical barrel reactor, and the ratio of the diameter to the height is 1:3 to 5:1. The multi-stage cutting stirrer 10 is equipped with three layers of spiral blade impellers. The spacing between each layer of spiral blade impellers is 1 / 7 to 1 / 4 of the height of the macro / micro structure modification reactor 9. The spiral blade impellers are distributed blades made of stainless steel. The first and third layers of spiral blade impellers are three-blade impellers arranged at an interval of 120°, and the blades are twisted by 35° to 55°. The second layer of spiral blade impellers is six-blade impellers arranged at an interval of 60°, and the blades are twisted by 25° to 45°. The lengths of the spiral blade impellers are all 1 / 4 to 2 / 5 of the inner diameter of the macro / micro structure modification reactor 9. The mesh number of the suspended filter cloth 27 is ≥200 meshes, and the pore diameter of the filter screen 34 is ≤0.1 mm.

[0031] This application uses alkaline plant ash to couple with multi-stage mechanical granulation to treat organic waste. Due to the synergistic effect of multi-stage mechanical granulation promoting the macrostructure modification of organic waste and alkaline plant ash inducing the microstructure modification of organic matter, the overall mass transfer efficiency and hydrothermal activity are improved, which can promote the hydrothermal reaction to tend towards inorganic carbonization reaction, reduce the generation of by-products such as odor and oil, and finally the content of by-products is lower than that of the same type of technology.

[0032] The addition of alkaline plant ash in this application first plays a role in alkaline pre-deconstruction of organic waste, modifying the microstructure of organic waste, and then plays a role in increasing potassium element and improving the quality of hydrochar particles. Different from the traditional treatment method of adding plant ash to the dehydration link of organic waste (such as sludge), in this application, alkaline plant ash is added after the moisture content adjustment (step S1), pre-crushing (step S2), and multi-stage mechanical granulation (step S3, that is, macrostructure modification) of organic waste. The alkaline plant ash is mixed with organic waste with a moisture content of 80-90% and a macrostructure of uniform small particles, and then the mixture is immediately put into a hydrothermal reaction kettle for hydrothermal carbonization treatment. This alkaline plant ash addition method and process flow have the advantages that there is no loss of alkaline plant ash (in the traditional addition method, alkaline plant ash is lost with the dehydration filtrate during dehydration), the potassium element of the product is increased, the action of alkaline plant ash is more persistent (it gradually dissolves and reacts with organic matter molecules during the hydrothermal carbonization reaction, rather than the rapid dissolution and short-time reaction of the traditional addition method), and alkaline plant ash can play a catalytic role during hydrothermal carbonization (after the alkaline plant ash is added and mixed evenly, the mixture is immediately put into the hydrothermal reaction kettle, so alkaline plant ash can participate in the hydrothermal carbonization process). These advantages help to reduce the reaction temperature, reaction time, and reaction pressure of hydrothermal carbonization, and improve the hydrochar yield and the physical and chemical structure properties of hydrochar particles during hydrothermal carbonization.

[0033] The order of adding plant ash is different, and the treatment purposes are also different. In the prior art, adding plant ash is to condition sludge and improve sludge dewaterability, which has nothing to do with the pyrolysis carbonization process; in this application, adding plant ash is for alkaline hydrolysis to modify and optimize the microstructure of organic matter (especially useful for modifying the biomass microstructure of plant ash when there is a lot of cellulose in garden green waste and agricultural and forestry wastes), and at the same time to catalyze the activity of hydrothermal reaction.

[0034] The alkaline plant ash used in this application is an agricultural and forestry waste, with the benefit of "treating waste with waste". In addition, this application does not use any other chemical agents; compared with other technologies that add various chemical agents such as coagulants, additives, and conditioners, this application can be considered to have no chemical agent consumption, and the economic and resource-saving benefits are significant; at the same time, the multi-stage mechanical granulation of this application only requires vibration and cutting and stirring, with low energy consumption and low treatment cost; after the treatment of alkaline plant ash coupled with multi-stage mechanical granulation, the temperature required for the hydrothermal carbonization of organic waste is reduced, the saturated vapor pressure is reduced, the reaction time is shortened, and the energy consumption of the hydrothermal reaction is greatly reduced, with the advantages of economic energy saving; therefore, the overall economy of this application is significant and superior to the same type of technology.

[0035] This application proposes detailed implementation methods, operation modes and technical parameters according to the component structure characteristics of different organic wastes, can adapt to various organic wastes such as excess sludge, fruit and vegetable waste, and garden green waste, and can flexibly match organic wastes with different properties, and has good flexibility and stability in the implementation of the invention and the operation of the technology.

[0036] Example 1 This example provides a method for strengthening the hydrothermal carbonization of organic waste and recovering potassium-rich soil conditioner by coupling alkaline plant ash with multi-stage mechanical granulation, including the following specific steps: S1. When the moisture content of the dewatered sludge is <80%, the dewatered sludge is added into the moisture content adjustment tank 1 from the first organic waste addition port 2, clear water is injected through the water tank 4 and the water addition port 3, and the first stirring device 5 is used to mix and stir the dewatered sludge and clear water to obtain the organic waste A with adjusted moisture content. The moisture content of the organic waste A is detected by the moisture content detector 37, and the injection amount of clear water is adjusted until the moisture content of the organic waste A is 80-90%, and the organic waste A is discharged from the first discharge port 6; S2. The organic waste A is added into the macro / microstructure modification reactor 9 from the second organic waste addition port 12 by the first screw feeder 8, and the multi-stage cutting stirrer 10 is used to perform low-speed cutting and stirring on the organic waste A for 1-5 minutes, and the rotation speed is set to 100-250 rpm to initially break the structure of the organic waste A and obtain the uneven blocky organic waste B; S3. Turn on the vibration fluidization device 11 and perform high-frequency vibration fluidization on the organic waste B at a vibration frequency of 200 - 700 r / min. At the same time, change the rotation speed of the multi-stage cutting stirrer 10 to 250 - 700 rpm, and use the multi-stage cutting stirrer 10 to perform high-speed cutting and stirring on the organic waste B for 5 - 15 min under high-speed cutting and stirring conditions. Through the combined action of vibration fluidization and multi-stage mechanical cutting and stirring, the organic waste B is transformed into a uniform small particle form, thereby modifying the macroscopic structure of the organic waste B, realizing multi-stage mechanical granulation of the organic waste, and obtaining the organic waste C in the form of uniform small particles. The average particle size of the obtained organic waste C is 3 - 20 mm. S4. Add alkaline plant ash (pH is 10.5 - 12, soluble K element content ≥ 7%) into the macro / micro structure modification reactor 9 through the solid metering feeding device 13 and the alkaline plant ash feeding port 14. The dosage of alkaline plant ash is 0.25 - 1.25 g / g TS of the organic waste C. Use the multi-stage cutting stirrer 10 to stir at a low rotation speed of 50 - 150 rpm for 1 - 3 min. At the same time, use the vibration fluidization device to perform low-frequency vibration fluidization on the organic waste C and the alkaline plant ash at a vibration frequency of 100 - 450 r / min to improve the mixing uniformity of the organic waste C and the alkaline plant ash. Use the alkaline plant ash to promote the alkaline deconstruction of the organic waste C and modify the microscopic structure of the organic waste C to obtain the mixture D of the organic waste C and the alkaline plant ash. Use the pH meter 40 to detect the pH value of the mixture D, which is 9.0 - 10.5. If it does not meet the requirement, change the dosage of alkaline plant ash and repeat step S4, and then discharge the mixture D from the second discharge port 15. S5. Use the second screw feeder 16 to add the mixture D into the hydrothermal reaction kettle 17 from the mixture feeding port 20. Use the heating and temperature control device 19 to ensure that the hydrothermal reaction is carried out at a temperature of 170 - 200 °C for 25 - 50 min. At the same time, use the second stirring device 18 to stir the mixture D at a rotation speed of 20 - 100 rpm. During this process, the hydrothermal reaction kettle is strictly sealed, and use the pressure monitoring device 21 to monitor the pressure to maintain a saturated steam pressure environment. After completing the hydrothermal carbonization reaction, turn off the heating and temperature control device 19. After the temperature drops to 100 °C, open the pressure relief valve and the explosion-proof sheet 23 to relieve the pressure, and obtain the hydrothermal carbonization mixed product E, which is discharged from the third discharge port 22. S6. Use the feed pump 24 to add the hydrothermal carbonization mixed product E into the suspended percolation tank 25. The upper layer of the suspended percolation tank is equipped with an upper filter cloth support 26 and a suspended filter cloth 27. Use the metal cloth plate 28 and the mechanical transmission mechanism 29 to evenly spread the hydrothermal carbonization mixed product E on the surface of the suspended filter cloth 27 and let it stand for 1 - 12 h to achieve gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth is the hydrothermal carbon particles, and the liquid that percolates from the suspended filter cloth into the suspended percolation tank 25 is the hydrothermal liquid. S7. Use the moisture content detector 37 to detect the moisture content of the hydrothermal carbon particles. If the moisture content ≤ 40%, proceed to the next step. If the moisture content > 40%, repeat step S6 until the moisture content ≤ 40%. S8. Collect the hydrothermal carbon particles from the surface of the suspended filter cloth 27, put them into the cleaning tank 32, inject clear water into the cleaning tank 32 from the cleaning and storage tank 36, and use the third stirring device 33 to stir at a rotation speed of 100 - 300 rpm for 0.5 - 2 h, and repeat the cleaning 3 - 5 times to complete the cleaning of the hydrothermal carbon particles. Then discharge the cleaning water from the cleaning water discharge port 35 at the bottom of the cleaning tank 32, and at the same time, use the filter screen 34 set at the cleaning water discharge port 35 to intercept the hydrothermal carbon particles. S9. Collect the cleaned hydrothermal carbon particles, lay them flat outdoors, and air-dry them under sunlight for 6 - 24 h to obtain dry hydrothermal carbon particles. Use the moisture content detector 37, elemental analyzer 38, capacitance tester 39, and pH meter 40 to detect the property indexes of the hydrothermal carbon particles, which should meet the requirements that the hydrothermal carbon yield ≥ 50%, the carbon element content of the hydrothermal carbon ≥ 30%, the phosphorus element content of the hydrothermal carbon ≥ 3%, the potassium element content of the hydrothermal carbon ≥ 2%, and the specific capacitance of the hydrothermal carbon ≥ 1.8 F / g. If the above index requirements are not met, mix them with the organic waste C and repeat steps S4 - S9 until the above index requirements are met, and collect the dry hydrothermal carbon for use as a soil conditioner. S10. Collect the hydrothermal liquid from the hydrothermal liquid collection hopper 30 at the bottom of the suspended percolation tank 25, and discharge it into the sewage treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0037] Example 2 The difference between this example and Example 1 is that the organic waste to be treated is fruit and vegetable waste. When its moisture content < 80%, the multi-stage cutting and stirring rotation speed in step S3 is 350 - 500 rpm, the cutting and stirring time is 5 - 20 min, and the average particle size of the obtained organic waste C should be 1 - 15 mm; the pH of the mixture D in step S4 should be 8.5 - 10.0; the hydrothermal temperature in step S5 should be 200 - 230 °C, and the hydrothermal treatment time should be 40 - 100 min; the number of times of cleaning the hydrothermal carbon particles in step S8 should be 2 - 4 times; the property indexes of the hydrothermal carbon particles in step S9 should meet: the hydrothermal carbon yield ≥ 30%, the carbon element content of the hydrothermal carbon ≥ 55%, the phosphorus element content of the hydrothermal carbon ≥ 0.15%, the potassium element content of the hydrothermal carbon ≥ 2.5%, and the specific capacitance of the hydrothermal carbon ≥ 6.5 F / g.

[0038] Example 3 The difference between this embodiment and Embodiment 1 is that the organic waste to be processed is garden greening waste. When its water content is <80%, the multi-stage cutting and stirring speed in Step S3 is 500 - 700 rpm, the cutting and stirring time is 10 - 20 min, and the average particle size of the obtained organic waste C is 1 - 15 mm; the pH of the mixture D in Step S4 should be 8.0 - 9.5; the hydrothermal temperature in Step S5 should be 200 - 230 °C, and the hydrothermal treatment time should be 40 - 100 min; the number of times of washing the hydrothermal carbon particles in Step S8 should be 1 - 3 times; the property indexes of the hydrothermal carbon particles in Step S9 should meet the requirements: the hydrothermal carbon yield ≥60%, the carbon element content of the hydrothermal carbon ≥60%, the phosphorus element content of the hydrothermal carbon ≥0.2%, the potassium element content of the hydrothermal carbon ≥1%, and the specific capacitance of the hydrothermal carbon ≥5 F / g.

[0039] Embodiment 4 The difference between this embodiment and Embodiment 1 is that when the water content of the dewatered sludge to be processed is 80 - 90%, Step S1 is not required.

[0040] Embodiment 5 The difference between this embodiment and Embodiment 1 is that when the water content of the dewatered sludge to be processed is >90%, Step S1 is changed to adding the dewatered sludge into the dehydrator 7 for secondary dehydration to obtain the organic waste A with adjusted water content. The water content of the organic waste A is detected by the water content detector 37, and the operating parameters of the dehydrator such as pressure and time are adjusted until the water content of the organic waste A is 80 - 90%, and then the organic waste A is discharged from the first discharge port 6. Embodiment 6 The difference between this embodiment and Embodiment 2 is that when the water content of the fruit and vegetable waste to be processed is 80 - 90%, Step S1 is not required.

[0041] Embodiment 7 The difference between this embodiment and Embodiment 2 is that when the water content of the fruit and vegetable waste to be processed is >90%, Step S1 is changed to adding the fruit and vegetable waste into the dehydrator 7 for secondary dehydration to obtain the organic waste A with adjusted water content. The water content of the organic waste A is detected by the water content detector 37, and the operating parameters of the dehydrator such as pressure and time are adjusted until the water content of the organic waste A is 80 - 90%, and then the organic waste A is discharged from the first discharge port 6. Embodiment 8 The difference between this embodiment and Embodiment 3 is that when the water content of the garden greening waste to be processed is 80 - 90%, Step S1 is not required.

[0042] Embodiment 9 The difference between this embodiment and Embodiment 3 is that the moisture content of the landscaping waste to be processed is >90%. Step S1 is changed to feeding the landscaping waste into the dehydrator 7 for secondary dehydration to obtain the organic waste A with adjusted moisture content. The moisture content of the organic waste A is detected by the moisture content detector 37, and the operating parameters of the dehydrator such as pressure and time are adjusted until the moisture content of the organic waste A is 80-90%. Then the organic waste A is discharged from the first discharge port 6.

[0043] Embodiment 10 As Figure 4 shown, the present application discloses a method for coupling and granulating plant ash to strengthen hydrothermal carbonization of organic waste, comprising the following steps: S1: Moisture content adjustment, using the method of dilution or dehydration; S2: Preliminary crushing, using the method of low-speed cutting and stirring; S3: Multi-stage mechanical granulation, high-frequency vibration fluidization + high-speed cutting and stirring; S4: Alkaline plant ash treatment, low-frequency vibration fluidization + low-speed cutting and stirring; S5: Hydrothermal carbonization: S6: Suspended percolation to obtain hydrothermal carbon particles and hydrothermal liquid; S7: Moisture content detection. If the moisture content ≤ 40%, then proceed to the next step. If the moisture content > 40%, then repeat S6 until the moisture content ≤ 40%; S8: Hydrothermal carbon cleaning; S9: Natural drying; Detection of the properties of hydrothermal carbon: If it meets the standards, it is used as a high-quality potassium-rich soil conditioner; If it does not meet the standards, then repeat S4; S10: Collection and discharge of hydrothermal liquid, which is used as a supplementary carbon source.

[0044] Application Example 1 Dewatered sludge is obtained from a sewage treatment plant. The moisture content of the dewatered sludge is detected by a moisture content detector 37 to be 85%. 1L of the dewatered sludge is added into the macro / micro structure modification reactor 9 from the second organic waste addition port 12 using the first screw feeder 8. The diameter: height of the macro / micro structure modification reactor 9 is 1.5:1. It has a built-in multi-stage cutting agitator and is equipped with three layers of spiral blades. The spacing between blades in each layer is 1 / 5 of the effective height of the macro / micro structure modification reactor. The spiral blades are distributed blades made of stainless steel. The first and third layers of spiral blades are three blades arranged at an interval of 120°, and the blades are twisted by 45°. The second layer of spiral blades is six blades arranged at an interval of 60°, and the blades are twisted by 30°. The length of the blades is 1 / 3 of the effective inner diameter of the macro / micro structure modification reactor. The dewatered sludge was cut and stirred for 3 minutes by using the multi-stage cutting stirrer 10, and the rotation speed was set to 200rpm, so as to preliminarily break the structure of the dewatered sludge and obtain the uneven block dewatered sludge B. Then, the vibration fluidization device 11 was turned on, and the dewatered sludge B was vibrated and fluidized at a vibration frequency of 500r / min. At the same time, the rotation speed of the multi-stage cutting stirrer 10 was changed to 350rpm. The dewatered sludge B was cut and stirred for 10 minutes by using the multi-stage cutting stirrer 10 under high-speed cutting and stirring conditions. Through the combined effect of vibration fluidization and multi-stage mechanical cutting and stirring, the dewatered sludge B was converted into a uniform small particle form, thereby modifying the macro structure of the dewatered sludge B, realizing multi-stage mechanical granulation of organic waste, and obtaining a uniform small particle form of dewatered sludge C, and the obtained dewatered sludge C particles had an average particle size of 15mm. Alkaline wood ash with a pH of 11.0 and a soluble K element content of 9% is added into the macro / microstructure modification reactor 9 through the solid metering feeding device 13 and the alkaline wood ash feeding port 14, the alkaline wood ash addition amount is 1.0 g / g TS sludge, and the multi-stage cutting agitator 10 is used to stir at a low speed of 100 rpm for 3 minutes. At the same time, the dewatered sludge C and the alkaline wood ash are vibrated and fluidized at a vibration frequency of 300 r / min by a vibration fluidization device to improve the mixing uniformity of the dewatered sludge C particles and the alkaline wood ash. The alkaline wood ash is used to promote the alkaline deconstruction of the dewatered sludge C particles and modify the microstructure of the dewatered sludge C particles to obtain a mixture D of the dewatered sludge C particles and the alkaline wood ash. The pH value of the mixture D is detected by a pH meter 40 to be 10.0.Then, the mixture D is discharged from the second discharge port 15, and the mixture is fed into the hydrothermal reactor 17 through the second screw feeder 16 from the mixture feeding port 20. The hydrothermal reaction is carried out at a temperature of 180 °C for 30 min by using the heating and temperature control device 19. At the same time, the mixture D is stirred by the second stirring device 18 at a rotation speed of 100 rpm. During this process, the hydrothermal reactor is strictly sealed, and the pressure is monitored by the pressure monitoring device 21 to maintain a saturated vapor pressure environment. After the hydrothermal carbonization reaction is completed, the heating and temperature control device 19 is turned off. After the temperature drops to 100 °C, the pressure relief valve and the explosion-proof sheet 23 are opened to relieve the pressure, and the hydrothermal carbonization mixed product E is obtained. It is discharged from the third discharge port 22, and then the hydrothermal carbonization mixed product E is fed into the suspended percolation tank 25 by using the feed pump 24. The suspended percolation tank is 6 m long and 2 m wide. The upper layer of the suspended percolation tank is equipped with an upper filter cloth support 26, and a suspended filter cloth 27 of the same size as the suspended filter tank is provided. The mesh number of the suspended filter cloth is 250 meshes. The hydrothermal carbonization mixed product is evenly spread on the surface of the suspended filter cloth 27 by using the metal cloth plate 28 and the mechanical transmission device 29, and left standing for 10 h to realize gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth is the sludge hydrothermal carbon particles, and the liquid that percolates from the suspended filter cloth into the suspended percolation tank is the hydrothermal liquid. The moisture content of the hydrothermal carbon particles is detected by the moisture content detector 37 to be 20%. The hydrothermal carbon particles are collected from the surface of the suspended filter cloth and put into the cleaning tank 32. Clear water is injected into the cleaning tank from the cleaning storage tank 36, and stirred at a rotation speed of 300 rpm for 1 h by using the third stirring device 33, and washed 5 times repeatedly to complete the cleaning of the hydrothermal carbon particles. Then, the cleaning water is discharged from the cleaning water discharge port 35 at the bottom of the cleaning water tank, and at the same time, the hydrothermal carbon particles are intercepted by the filter screen 34 arranged at the discharge port. The aperture of the filter screen is 0.08 mm. The cleaned hydrothermal carbon particles are collected, spread out outdoors, and air-dried under sunlight for 18 h to obtain dry sludge hydrothermal carbon particles. The property indexes of the sludge hydrothermal carbon particles are detected by the elemental analyzer 38 and the capacitance tester 39, and the results are as follows. Figure 2 As shown: the yield of hydrothermal carbon is 54.54%, higher than 38.45% of the traditional hydrothermal carbonization treatment in the control group; the carbon element content of the hydrothermal carbon product is 31.15%, higher than 26.53% of the control group; the phosphorus element content of the hydrothermal carbon product is 3.5%, higher than 3.477% of the control group; the potassium element content of the hydrothermal carbon product is 2.668%, higher than 0.018% of the control group. This is mainly because a large amount of potassium element is introduced into the sludge hydrothermal carbon by alkaline plant ash; the specific capacitance of the hydrothermal carbon product is 2.027 F / g, higher than 1.333 F / g of the control group, and has better electrochemical properties. The above properties of the hydrothermal carbon particles meet the requirements, and the dry sludge hydrothermal carbon is collected for use as a soil conditioner. At the same time, the hydrothermal liquid is collected from the hydrothermal liquid collection hopper 30 at the bottom of the suspended percolation tank 25, and discharged into the sewage treatment system through the hydrothermal liquid discharge pipe and the valve 31 as a supplementary carbon source.

[0045] Application Example 2 Garden green waste is obtained from urban gardens. The water content of the garden green waste is detected by a water content detector 37 to be 20%. The garden green waste is added into the water content regulating tank 1 from the first organic waste adding port 2. Clean water is injected through the water tank 4 and the water adding port 3. The garden green waste and the clean water are mixed and stirred by the first stirring device 5 to obtain garden green waste A after adjusting the water content. The water content of the garden green waste is detected by the water content detector 37 to be 85%. The garden green waste A is discharged from the first discharge port 6. 1L of the adjusted garden green waste is discharged from the second organic waste adding port 12 by the first screw feeder 8. Added into the macro / micro structure modification reactor 9, the diameter of the macro / micro structure modification reactor 9 is 1:1, the multi-stage cutting stirrer is built-in, and three layers of spiral blades are installed. The spacing between each layer of blades is 1 / 5 of the effective height of the macro / micro structure modification reactor. The spiral blades are distributed blades made of stainless steel. The first and third layers of spiral blades are arranged with three blades at an interval of 120°, and the blades are twisted by 45°. The second layer of spiral blades is arranged with six blades at an interval of 60°, and the blades are twisted by 30°. The length of the blades is 1 / 3 of the effective inner diameter of the macro / micro structure modification reactor. The multi-stage cutting stirrer 10 is used to cut and stir the garden greening garbage A for 5 minutes, and the speed is set to 200rpm to preliminarily break the structure of the garden greening garbage A to obtain uneven block garden greening garbage B.Subsequently, start the vibrating fluidization device 11, vibrate and fluidize the garden green waste B at a vibration frequency of 500 r / min, and at the same time change the rotation speed of the multi-stage cutting stirrer 10 to 700 rpm. Under the condition of high-speed cutting and stirring, use the multi-stage cutting stirrer 10 to cut and stir the garden green waste B for 15 min. Through the combined action of vibrating fluidization and multi-stage mechanical cutting and stirring, the garden green waste B is transformed into a uniform small particle form, thereby modifying the macroscopic structure of the garden green waste B and realizing multi-stage mechanical granulation of organic waste, obtaining the garden green waste C in the form of uniform small particles. The average particle size of the obtained garden green waste C particles should be 8 mm; add the alkaline plant ash with a pH of 11 and a soluble K element content of 9% into the macro / micro structure modification reactor 9 through the solid metering and feeding device 13 and the alkaline plant ash feeding port 14. The dosage of the alkaline plant ash is 0.8 g / g TS of the garden green waste. Use the multi-stage cutting stirrer 10 to stir at a low rotation speed of 100 rpm for 3 min. At the same time, use the vibrating fluidization device to vibrate and fluidize the garden green waste C particles and the alkaline plant ash at a vibration frequency of 350 r / min to improve the mixing uniformity of the garden green waste C particles and the alkaline plant ash. Use the alkaline plant ash to promote the alkaline deconstruction of the garden green waste C particles and modify the microscopic structure of the garden green waste C particles to obtain a mixture D of the garden green waste C particles and the alkaline plant ash. Use the pH meter 40 to detect the pH value of the mixture, which is 9.0, and then discharge the mixture D from the second discharge port 15; use the second screw feeder 16 to feed the mixture D from the mixture feeding port 20 into the hydrothermal reaction kettle 17, and carry out a hydrothermal reaction for 60 min at a temperature of 220 °C set by the heating and temperature control device 19. At the same time, use the second stirring device 18 to stir the mixture D at a rotation speed of 100 rpm. During this process, the hydrothermal reaction kettle is strictly sealed, and the pressure is monitored by the pressure monitoring device 21 to maintain a saturated steam pressure environment. After the hydrothermal carbonization reaction is completed, turn off the heating and temperature control device 19. After the temperature drops to 100 °C, open the pressure relief valve and the explosion-proof sheet 23 to relieve the pressure, obtaining a hydrothermal carbonization mixed product E, discharging it from the third discharge port 22 and using the feed pump 24 to feed the hydrothermal carbonization mixed product E into the suspended percolation pond 25. The suspended percolation pond is 6 m long and 2 m wide. An upper filter cloth support 26 is installed on the upper layer of the suspended percolation pond, and a suspended filter cloth 27 equal in size to the suspended percolation pond is provided. The mesh number of the suspended filter cloth is 250 meshes. Use the metal cloth plate 28 and the mechanical transmission machine 29 to evenly spread the hydrothermal carbonization mixed product on the surface of the suspended filter cloth 27 and let it stand for 8 h to achieve gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth is the garden green hydrothermal carbon particles, and the liquid that percolates from the suspended filter cloth into the suspended percolation pond is the hydrothermal liquid; use the moisture content detector 37 to detect that the moisture content of the hydrothermal carbon particles is 20%.Collect the hydrochar particles from the surface of the suspended filter cloth and put them into the cleaning tank 32. Inject clean water into the cleaning tank from the cleaning and storage tank 36. Stir with the third stirring device 33 at a speed of 300 rpm for 1 h, repeat the cleaning 2 times to complete the cleaning of the hydrochar particles. Then discharge the cleaning water from the cleaning water discharge port 35 at the bottom of the cleaning water tank. At the same time, intercept the hydrochar particles with the filter screen 34 set at the discharge port. The aperture of the filter screen is 0.08 mm. Collect the cleaned hydrochar particles, lay them flat outdoors, and air-dry them under sunlight for 24 h to obtain dry hydrochar particles for landscaping. Use an elemental analyzer 38 and a capacitance tester 39 to detect the property indexes of the hydrochar particles for landscaping. The results are as follows. Figure 3 As shown: the yield of hydrochar is 68.82%, higher than 62.52% of the traditional hydrothermal carbonization treatment in the control group; the carbon element content of the hydrochar product is 64.89%, higher than 44.12% of the control group; the phosphorus element content of the hydrochar product is 0.207%, higher than 0.198% of the control group; the potassium element content of the hydrochar product is 1.66%, higher than 0.04% of the control group. This is mainly because a large amount of potassium element is introduced into the hydrochar for landscaping by alkaline plant ash; the specific capacitance of the hydrochar product is 5.10 F / g, higher than 3.34 F / g of the control group, and it has better electrochemical properties. The above properties of the hydrochar particles meet the requirements. Collect the dry hydrochar particles for landscaping and use them as a soil conditioner. At the same time, collect the hydrothermal liquid from the hydrothermal liquid collection hopper 30 at the bottom of the suspended percolation tank 25, and discharge it into the sewage treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0046] Application Example Three Fruit and vegetable garbage is obtained from a residential area. The moisture content of the fruit and vegetable garbage is detected by a moisture content detector 37 to be 96%. The fruit and vegetable garbage is added into a dehydrator 7 for secondary dehydration. The operating pressure of the dehydrator is adjusted to dehydrate for 20 minutes to obtain the fruit and vegetable garbage after the moisture content is adjusted. The moisture content of the fruit and vegetable garbage is detected by a moisture content detector 37 to be 86%. The fruit and vegetable garbage is discharged from the first discharge port 6. 1L of the fruit and vegetable garbage is added into the macro / micro structure modification reactor 9 from the second organic waste addition port 12 by the first screw feeder 8. The macro / micro structure modification reactor 9 is used for the first discharge port 6. The reactor 9 has a diameter:height ratio of 1:1, a built-in multi-stage cutting stirrer, and is equipped with three layers of spiral blades. The spacing between blades in each layer is 1 / 5 of the effective height of the macro / micro structure modification reactor. The spiral blades are distributed blades made of stainless steel. The first and third layers of spiral blades are arranged with three blades at an interval of 120°, and the blades are twisted by 45°. The second layer of spiral blades is arranged with six blades at an interval of 60°, and the blades are twisted by 30°. The length of the blades is 1 / 3 of the effective inner diameter of the macro / micro structure modification reactor. The multi-stage cutting stirrer 10 is used to cut and stir the fruit and vegetable waste for 5 minutes, and the speed is set to 150rpm to preliminarily break the structure of the fruit and vegetable waste and obtain uneven block fruit and vegetable waste. Then, the vibrating fluidizing device 11 is turned on to perform vibrating fluidization on the fruit and vegetable waste at a vibration frequency of 500 r / min. At the same time, the rotation speed of the multi-stage cutting stirrer 10 is changed to 450 rpm. The fruit and vegetable waste is cut and stirred for 20 minutes using the multi-stage cutting stirrer 10 under high-speed cutting and stirring conditions. Through the combined effects of vibrating fluidization and multi-stage mechanical cutting and stirring, the fruit and vegetable waste is converted into a uniform small particle form, thereby modifying the macro structure of the fruit and vegetable waste, realizing multi-stage mechanical granulation of the fruit and vegetable waste, and obtaining fruit and vegetable waste in a uniform small particle form. The obtained fruit and vegetable waste particles have an average particle size of 18 mm.The alkaline plant ash with a pH of 11 and a soluble K element content of 9% is added into the macro / micro structure modification reactor 9 through the solid metering feeding device 13 and the alkaline plant ash feeding port 14. The dosage of the alkaline plant ash is 1.25 g / g TS of fruit and vegetable waste. The multi-stage cutting stirrer 10 is used to stir at a low speed of 150 rpm for 3 min. At the same time, the vibration fluidization device is used to vibrate and fluidize the fruit and vegetable waste and the alkaline plant ash at a vibration frequency of 200 r / min to improve the mixing uniformity of the fruit and vegetable waste particles and the alkaline plant ash. The alkaline plant ash is used to promote the alkaline deconstruction of the fruit and vegetable waste particles and modify the micro-structure of the fruit and vegetable waste particles to obtain a mixture D of the fruit and vegetable waste particles and the alkaline plant ash. The pH meter 40 is used to detect that the pH value of the mixture D is 10.0. Then, the mixture is discharged from the second discharge port 15, and the second screw feeder 16 is used to add the mixture D into the hydrothermal reaction kettle 17 from the mixture feeding port 20. The hydrothermal reaction is carried out at a temperature of 220 °C for 60 min through the heating and temperature control device 19. At the same time, the second stirring device 18 is used to stir the mixture D at a speed of 80 rpm. During this process, the hydrothermal reaction kettle is strictly sealed, and the pressure monitoring device 21 is used to monitor the pressure to maintain a saturated steam pressure environment. After the hydrothermal carbonization reaction is completed, the heating and temperature control device 19 is turned off. After the temperature is reduced to 100 °C, the pressure relief valve and the explosion-proof sheet 23 are opened for pressure relief to obtain a hydrothermal carbonization mixed product E, which is discharged from the third discharge port 22. The hydrothermal carbonization mixed product E is added into the suspended percolation tank 25 by the feeding pump 24. The suspended percolation tank is 6 m long and 2 m wide. The upper layer of the suspended percolation tank is equipped with an upper filter cloth support 26, and a suspended filter cloth 27 equal to the size of the suspended filter tank is provided. The mesh number of the suspended filter cloth is 250 meshes. The metal cloth plate 28 and the mechanical transmission machine 29 are used to evenly spread the hydrothermal carbonization mixed product on the surface of the suspended filter cloth 27 and stand still for 10 h to realize gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth is the fruit and vegetable hydrothermal carbon particles, and the liquid that percolates from the suspended filter cloth into the suspended percolation tank is the hydrothermal liquid. The moisture content detector 37 is used to detect that the moisture content of the fruit and vegetable hydrothermal carbon particles is 35%. The fruit and vegetable hydrothermal carbon particles are collected from the surface of the suspended filter cloth and put into the cleaning tank 32. Clean water is injected into the cleaning tank from the cleaning storage tank 36. The third stirring device 33 is used to stir at a speed of 300 rpm for 1 h and repeat the cleaning 3 times to complete the cleaning of the fruit and vegetable hydrothermal carbon particles. Then, the cleaning water is discharged from the cleaning water discharge port 35 at the bottom of the cleaning water tank, and at the same time, the filter screen 34 arranged at the discharge port is used to intercept the fruit and vegetable hydrothermal carbon particles. The aperture of the filter screen is 0.08 mm; the cleaned fruit and vegetable hydrothermal carbon particles are collected and spread out outdoors and dried in the sun for 24 h to obtain dry fruit and vegetable hydrothermal carbon particles. The element analyzer 38 and the capacitance tester 39 are used to detect the property indexes of the fruit and vegetable hydrothermal carbon particles, and the results are as follows. Figure 4As shown, the yield of hydrochar is 39.11%, higher than 28.68% of the traditional hydrothermal carbonization treatment in the control group; the carbon element content of the hydrochar product is 61.66%, close to 63.78% of the control group; the phosphorus element content of the hydrochar product is 0.18%, higher than 0.164% of the control group; the potassium element content of the hydrochar product is 3.229%, higher than 0.0185% of the control group. This is mainly because a large amount of potassium element is introduced into the hydrochar of fruits and vegetables by alkaline plant ash; the specific capacitance of the hydrochar product is 6.73 F / g, higher than 2.98 F / g of the control group, with better electrochemical properties. Other indicators of the hydrochar product in this application are stronger than those of the control group, and the carbon element is close to that of the control group. The overall quality is superior to that of the control group; the particle properties of the hydrochar meet the requirements, and the collected and dried hydrochar of fruits and vegetables is used as a soil conditioner. At the same time, the hydrothermal liquid is collected from the hydrothermal liquid collecting hopper 30 at the bottom of the suspended percolation pond 25 and discharged into the sewage treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0047]

[0048] As can be seen from the above table, compared with the traditional hydrothermal carbonization technology, after the organic waste in this application is treated by coupling alkaline plant ash with multi-stage mechanical granulation, the yield of hydrochar can be increased by 10 - 40%; the carbon element content can be increased by up to 47% at most, the phosphorus element content can be increased by up to 9.8% at most, and the potassium element content can be increased by up to 17,000 times, effectively enriching the nutrient elements of the hydrochar particles; in addition, the specific capacitance of the hydrochar particles can be increased by 50 - 125%, obtaining more excellent electrochemical properties.

[0049] The principle of this application is as follows: This application uses a vibration fluidization device to vibrate and fluidize organic waste, and uses a three-layer spiral blade impeller to perform multi-stage cutting and stirring on organic waste. Under the combined action of the two, multi-stage mechanical granulation of organic waste is realized, the macroscopic structure of organic waste is destroyed and modified, and it becomes uniform small particle organic waste; subsequently, alkaline plant ash is used to promote the alkaline deconstruction of biomass molecules of uniform small particle organic waste, destroy and modify the microscopic structure of organic waste, and improve the hydrothermal activity; under the coupling action of the above multi-stage mechanical granulation and alkaline plant ash, the macroscopic and microscopic structures of organic waste are synchronously modified and transformed, improving the hydrothermal carbonization efficiency and the recovery rate of hydrochar products, and inhibiting the generation of by-products, solving the bottleneck constraints that the macroscopic physical structure of organic waste limits the hydrothermal mass transfer efficiency, and the microscopic chemical structure of biomass such as cellulose limits the hydrolysis efficiency and hydrothermal activity; at the same time, alkaline plant ash contains rich potassium elements, which can supplement potassium fertilizer for organic waste, increase the potassium fertilizer content of hydrochar products, enrich and improve the distribution of nutrient element composition of hydrochar products, and enhance the quality of hydrochar products as soil conditioners and their soil remediation effects.

[0050] After the organic waste is treated by the above-mentioned alkaline plant ash coupled multi-stage mechanical granulation, it is subjected to hydrothermal carbonization treatment under specific hydrothermal temperature and saturated vapor pressure conditions. After treatment, the mixture is subjected to percolation dehydration on a suspended filter cloth to achieve solid-liquid separation. The obtained solid-phase hydrochar is washed and dried and then recycled for use as a soil conditioner, and the hydrothermal liquid is discharged for anaerobic digestion to produce methane or discharged into the sewage treatment system as a supplementary carbon source. This application uses specific devices and supporting technical parameters to realize the disposal of organic waste, and specific technical parameters are proposed for three types of organic waste, namely dewatered sludge, fruit and vegetable waste, and garden greening waste, which can be flexibly matched with different categories of organic waste. In addition, this application proposes evaluation indicators for hydrochar products, and a detector is built into the device to limit the ranges of hydrochar yield, carbon, phosphorus, and potassium element ratios, and hydrochar specific capacitance indicators. If the indicator requirements are not met, secondary treatment is required to ensure the stable technical effect of this application and the quality of the potassium-rich super-high-quality hydrochar products.

[0051] This application efficiently converts organic waste into potassium-rich high-quality hydrochar products. Through the functions of hydrochar products such as increasing soil porosity, changing the particle composition of the soil, increasing soil water retention, supplementing carbon, nitrogen, phosphorus, and potassium elements to improve soil fertility, adsorbing and preserving nutrients in the soil to reduce nutrient loss, regulating soil pH, promoting soil microbial activities and decomposing organic substances, and improving soil enzyme activity, soil improvement and restoration are achieved.

[0052] The preferred embodiments of this application are described in detail above, but this application is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art, various changes can be made without departing from the purpose of this application.

[0053] Many other changes and modifications can be made without departing from the concept and scope of this application. It should be understood that this application is not limited to specific embodiments, and the scope of this application is defined by the appended claims.

Claims

1. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that, The following steps are involved: S1: dehydrating the organic waste or diluting it with water to adjust the moisture content of the organic waste to 80-90%, thereby obtaining organic waste A after adjusting the moisture content; S2: putting the organic waste A into the macro / micro structure modification reactor (9), and using the multi-stage cutting stirrer (10) to cut and stir the organic waste A at a low speed, thereby preliminarily breaking the structure of the organic waste A to obtain an uneven block of organic waste B; S3: using a vibrating fluidizing device (11) to perform high-frequency vibration fluidization on the organic waste B, and simultaneously using a multi-stage cutting and stirring device (10) to perform high-speed cutting and stirring on the organic waste B, so that the organic waste B is converted into a uniform small particle form through the combined action of the high-frequency vibration fluidization and the high-speed cutting and stirring, thereby modifying the macro structure of the organic waste B, and obtaining an organic waste C in a uniform small particle form; S4: adding alkaline wood ash to the macro / micro structure modification reactor (9), wherein the amount of alkaline wood ash added is 0.25-1.25 g / g TS of organic waste C, and performing low-speed cutting and stirring. At the same time, a vibration fluidization device (11) is used to perform low-frequency vibration fluidization on the organic waste C and the alkaline wood ash, and the alkaline wood ash is used to promote alkaline decomposition of the organic waste C, thereby modifying the microstructure of the organic waste C, and obtaining a mixture D of the organic waste C and the alkaline wood ash, wherein the pH of the mixture D is 8.0-10.5; S5: adding the mixture D into the hydrothermal reactor (17), performing a hydrothermal reaction at a temperature of 160-230° C. for 25-100 min, and stirring the mixture D at a speed of 20-100 rpm. During this process, the hydrothermal reactor (17) is strictly closed to maintain a saturated vapor pressure environment, completing the hydrothermal carbonization reaction, and obtaining a hydrothermal carbonization mixed product E; S6: adding the hydrothermal carbonization mixed product E into the suspended percolation tank (25) for solid-liquid separation to obtain hydrothermal carbon particles and hydrothermal liquid respectively; S7: Detect the moisture content of the hydrothermal carbon particles. If the moisture content is ≤40%, proceed to the next step. If the moisture content is >40%, repeat S6 until the moisture content is ≤40%. S8: collecting the hydrothermal carbon particles and placing them into a cleaning tank (32) to clean the hydrothermal carbon particles, then discharging the cleaning water from a cleaning water outlet (35) at the bottom of the cleaning tank (32), while using a filter (34) disposed at the cleaning water outlet (35) to intercept the hydrothermal carbon particles; S9: Collect the washed hydrothermal carbon particles, lay them flat outdoors, and air-dry them for 6 to 24 hours under sunlight to obtain dry hydrothermal carbon particles. Detect the carbon, nitrogen, phosphorus, and potassium element ratios and specific capacitance indicators of the hydrothermal carbon particles. If they are qualified, collect them for use as soil conditioners. S10: Collect the hydrothermal fluid from the bottom of the suspended infiltration tank (25) and discharge it into the sewage treatment system as a supplementary carbon source.

2. The method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash according to claim 1, characterized in that: The organic waste in S1 is one or more of dewatered sludge, fruit and vegetable waste, and garden waste; When the moisture content of the organic waste is < 80%, add clear water to the organic waste to adjust the moisture content of the organic waste to 80 - 90%; when the moisture content of the organic waste is > 90%, dehydrate the organic waste to adjust the moisture content of the organic waste to 80 - 90%; when the moisture content of the organic waste is 80 - 90%, the S1 step is not required; In the said S2, use a multi-stage cutting and stirring device (10) to cut and stir the organic waste A at a low speed for 1 - 5 min, and set the rotation speed to 100 - 250 rpm.

3. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: In the said S3, use a vibration fluidization device (11) to perform high-frequency vibration fluidization on the organic waste B, with a vibration frequency of 200 - 700 r / min, and use a multi-stage cutting and stirring device (10) to cut and stir the organic waste B at a high speed for 5 - 20 min, and set the rotation speed to 250 - 700 rpm; When the organic waste is dewatered sludge, set the rotation speed of the multi-stage cutting and stirring device (10) to 250 - 350 rpm, cut and stir the organic waste B at a high speed for 5 - 15 min, and the average particle size of the obtained organic waste C is 3 - 20 mm; When the organic waste is fruit and vegetable waste, set the rotation speed of the multi-stage cutting and stirring device (10) to 350 - 500 rpm, cut and stir the organic waste B at a high speed for 5 - 20 min, and the average particle size of the obtained organic waste C is 1 - 15 mm; When the organic waste is landscaping waste, set the rotation speed of the multi-stage cutting and stirring device (10) to 500 - 700 rpm, cut and stir the organic waste B at a high speed for 10 - 20 min, and the average particle size of the obtained organic waste C is 1 - 15 mm.

4. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: The pH of the alkaline plant ash used in the said S4 is 10.5 - 12, and the soluble K element content is ≥ 7%; add the alkaline plant ash to the macro / micro structure modification reactor (9), stir at a rotation speed of 50 - 150 rpm for 1 - 3 min, and at the same time use a vibration fluidization device (11) to perform low-frequency vibration fluidization on the organic waste C and the alkaline plant ash, with a vibration frequency of 100 - 450 r / min.

5. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: In the said S4, add the alkaline plant ash and the organic waste C to obtain a mixture D, and by controlling the dosage of the alkaline plant ash, ensure that the pH of the mixture D is 8.0 - 10.5; When the organic waste is dewatered sludge, the pH of the mixture D is 9.0 - 10.5; When the organic waste is fruit and vegetable waste, the pH of the mixture D is 8.5 - 10.0; When the organic waste is landscaping waste, the pH of the mixture D is 8.0 - 9.

5.

6. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: In the said S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160 - 200 °C, and the hydrothermal time is 25 - 50 min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200 - 230 °C, and the hydrothermal time is 40 - 100 min; when the organic waste is landscaping waste, the hydrothermal temperature is 200 - 230 °C, and the hydrothermal time is 40 - 100 min; In S6, the hydrothermal carbonization mixture E is added into the suspended percolation tank (25). A suspended filter cloth (27) is arranged on the upper layer of the suspended percolation tank (25). The hydrothermal carbonization mixture E is evenly spread on the surface of the suspended filter cloth (27) by using the cloth plate (28), and left standing for 1 to 12 hours to achieve gravity percolation dehydration. The solid intercepted on the surface of the suspended filter cloth (27) is the hydrochar particles, and the liquid that percolates from the suspended filter cloth (27) into the suspended percolation tank (25) is the hydrothermal liquid.

7. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: In S8, the hydrochar particles are put into the cleaning tank (32) and stirred at a rotation speed of 100 to 300 rpm for 0.5 to 2 hours, and the cleaning is repeated 1 to 5 times; When the organic waste is dewatered sludge, the hydrochar particles are cleaned 3 to 5 times; When the organic waste is fruit and vegetable waste, the hydrochar particles are cleaned 2 to 4 times; When the organic waste is garden greening waste, the hydrochar particles are cleaned 1 to 3 times.

8. A method for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: The dried hydrochar particles in S9 are detected. The hydrochar yield of dewatered sludge is ≥50%, the hydrochar yield of fruit and vegetable waste is ≥30%, and the hydrochar yield of garden greening waste is ≥60%; The carbon element content of the hydrochar of dewatered sludge is ≥30%, the carbon element content of the hydrochar of fruit and vegetable waste is ≥55%, and the carbon element content of the hydrochar of garden greening waste is ≥60%; The phosphorus element content of the hydrochar of dewatered sludge is ≥3%, the phosphorus element content of the hydrochar of fruit and vegetable waste is ≥0.15%, and the phosphorus element content of the hydrochar of garden greening waste is ≥0.2%; The potassium element content of the hydrochar of dewatered sludge is ≥2%, the potassium element content of the hydrochar of fruit and vegetable waste is ≥2.5%, and the potassium element content of the hydrochar of garden greening waste is ≥1%; The specific capacitance of the hydrochar of dewatered sludge is ≥1.8 F / g, the specific capacitance of the hydrochar of fruit and vegetable waste is ≥6.5 F / g, and the specific capacitance of the hydrochar of garden greening waste is ≥5 F / g.

9. An apparatus for enhancing hydrothermal carbonization of organic waste by coupling with plant ash granulation, characterized in that: For the implementation of the method for coupling granulation of plant ash to strengthen hydrothermal carbonization of organic waste according to any one of claims 1 to 8, it includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended percolation module, a hydrochar particle cleaning module, a detection module and a control component. The moisture content adjustment module, the macro / micro structure modification module, the hydrothermal carbonization reaction module, the suspended percolation module, the hydrochar particle cleaning module and the detection module are respectively electrically connected to the control component; The moisture content adjustment module includes a moisture content adjustment tank (1) and a dehydrator (7). The moisture content adjustment tank (1) is provided with a first organic waste feeding port (2), a water adding port (3), a first stirring device (5) and a first discharge port (6). The water adding port (3) is connected to the water tank (4), and the dehydrator (7) is also provided with a first discharge port (6); The macro / micro structure modification module includes a first screw feeder (8) and a macro / micro structure modification reactor (9). The macro / micro structure modification reactor (9) is internally provided with a multi-stage cutting stirrer (10) and a vibration fluidization device (11). The macro / micro structure modification reactor (9) is further provided with a second organic waste feeding port (12), an alkaline plant ash feeding port (14), and a second discharge port (15). The vibration fluidization device (11) is arranged at the bottom of the macro / micro structure modification reactor (9). The solid metering and feeding device (13) is arranged at the top of the alkaline plant ash feeding port (14). The bottom of the first screw feeder (8) is connected to the first discharge port (6), and the top of the first screw feeder (8) is connected to the second organic waste feeding port (12). The hydrothermal carbonization reaction module includes a second screw feeder (16) and a hydrothermal reaction kettle (17). The hydrothermal reaction kettle (17) is internally provided with a second stirring device (18) and a heating and temperature control device (19). The hydrothermal reaction kettle (17) is further provided with a mixture feeding port (20), a pressure monitoring device (21), a third discharge port (22), and a pressure relief valve and explosion-proof sheet (23). The bottom of the second screw feeder (16) is connected to the second discharge port (15), and the top of the second screw feeder (16) is connected to the mixture feeding port (20). The suspended infiltration module includes a feed pump (24) and a suspended infiltration tank (25). An upper filter cloth support (26) is arranged in the suspended infiltration tank (25). A suspended filter cloth (27) is placed on the upper filter cloth support (26). A cloth plate (28) is arranged on the surface of the suspended filter cloth (27). The cloth plate (28) is connected to a mechanical transmission (29). A hydrothermal liquid collecting hopper (30) and a hydrothermal liquid discharge pipe and valve (31) are arranged at the bottom of the suspended infiltration tank (25). One end of the feed pump (24) is connected to the third discharge port (22), and the other end is connected to the top of the suspended filter cloth (27). The hydrothermal carbon particle cleaning module includes a cleaning water storage tank (36) and a cleaning tank (32). The cleaning tank (32) is internally provided with a third stirring device (33). A filter screen (34) and a cleaning water discharge port (35) are arranged at the bottom of the cleaning tank (32). The cleaning water storage tank (36) is connected to the cleaning tank (32). The detection module includes a moisture content detector (37), an elemental analyzer (38), a capacitance tester (39), and a pH meter (40). The moisture content detector (37) is used to detect the moisture content of the organic waste A at the first discharge port (6) and the hydrothermal carbon particles on the suspended filter cloth (27). The pH meter (40) is used to detect the pH of the mixture D at the second discharge port (15). The moisture content detector (37), the elemental analyzer (38), the capacitance tester (39), and the pH meter (40) are also used to detect the property indexes of the hydrothermal carbon particles at the filter screen (34).

10. A device for enhancing hydrothermal carbonization of organic waste by coupling granulation with plant ash, characterized in that: The macro / micro structure modification reactor (9) is a cylindrical barrel reactor, and the ratio of the diameter to the height is 1:3 to 5:

1. The multi-stage cutting stirrer (10) is equipped with three layers of spiral blade impellers. The spacing between each layer of spiral blade impellers is 1 / 7 to 1 / 4 of the height of the macro / micro structure modification reactor (9). The spiral blade impellers are distributed blades made of stainless steel. The first and third layers of spiral blade impellers are three-blade impellers arranged at an interval of 120°, and the blades are twisted by 35° to 55°. The second layer of spiral blade impellers is six-blade impellers arranged at an interval of 60°, and the blades are twisted by 25° to 45°. The lengths of the spiral blade impellers are all 1 / 4 to 2 / 5 of the inner diameter of the macro / micro structure modification reactor (9). The mesh number of the suspended filter cloth (27) is ≥ 200 meshes, and the pore diameter of the filter screen (34) is ≤ 0.1 mm.

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