Device and method for coupling wood ash to granulation and strengthening hydrothermal carbonization of organic waste

Abstract

The application belongs to the technical field of organic waste treatment, and discloses a device and method for strengthening hydrothermal carbonization of organic waste by coupling with wood ash and granulation, which utilizes a vibration fluidization device to perform vibration fluidization on the organic waste, utilizes three-layer spiral blade paddles to perform multi-stage cutting and stirring on the organic waste, and realizes multi-stage mechanical granulation of the organic waste under the joint action of the two, destroys and modifies the macrostructure of the organic waste, and changes the organic waste into uniform small-particle organic waste; subsequently, alkali wood ash is utilized to promote alkaline deconstruction of the biomass molecules of the uniform small-particle organic waste, destroy and modify the microstructure of the organic waste, and improve hydrothermal activity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic waste treatment, and particularly relates to a device and method for strengthening hydrothermal carbonization of organic waste by coupling with wood ash. BACKGROUND

[0002] The multi-source organic waste such as residual sludge, landscaping waste and fruit and vegetable waste has a huge output in China, and its resource disposal is one of the core contents of building a green and conservation-oriented city. At present, the traditional resource-consuming organic waste disposal mode is changing to a resource recycling type. Compared with traditional resource recycling methods such as anaerobic digestion, anaerobic fermentation, aerobic composting and high-temperature pyrolysis, carbonization technology has the advantages of short processing period, high carbon material recovery rate, full consumption of organic waste, no residue discharge and the like, and can recover high-quality carbon particles which can be used as high-quality carbon sequestration materials for soil improvement and remediation.

[0003] At present, carbonization technology mainly includes pyrolysis carbonization and hydrothermal carbonization. Pyrolysis carbonization needs to dry the organic waste, uses inert gas as the pyrolysis reaction medium, and converts the organic waste into biochar under anaerobic conditions at high temperature (300-800℃). Hydrothermal carbonization technology does not need to dry the organic waste, uses the water in the organic waste as the reaction medium, does not need to control anaerobic conditions, and converts the organic waste into hydrothermal carbon by hydrolysis, dehydration, decarboxylation, polymerization and aromatization at relatively low temperature (170-300℃), and obtains solid hydrothermal carbon particles and liquid hydrothermal carbon products. Compared with traditional pyrolysis carbonization, hydrothermal carbonization is a promising organic waste resource recycling technology, which has the advantages of no need for pre-drying, no need for anaerobic conditions, low reaction temperature and pressure, low energy consumption and cost, and the like, and has significant benefits.

[0004] However, the current hydrothermal carbonization technology still has problems such as high hydrothermal reaction thermodynamic barrier, poor mass transfer efficiency, and low hydrothermal efficiency in the disposal of organic waste. The uncontrolled direction of traditional hydrothermal reaction leads to the residue of by-products and poor quality of hydrothermal carbon, which limits the recycling prospect of hydrothermal carbon products. The fundamental reason is that the biomass molecular configuration of organic waste is stable and the catalytic activity is poor. The macrostructure of organic waste has the characteristics of large particle size, small specific surface area, and low porosity, which limits the mass transfer efficiency of hydrothermal conversion. At the same time, the microstructure of organic waste is stable, the hydrophilicity is poor, the hydrothermal activity of biomass structure is low, and the modification is poor, which leads to low hydrothermal conversion efficiency, greatly limiting the reaction process of hydrothermal carbonization. The by-products of hydrothermal carbonization are also one of the main bottlenecks that limit the efficiency of this technology. The traditional hydrothermal carbonization process is prone to produce by-products such as tar, and the intermediate volatile fatty acids will also destroy the structure of the hydrothermal carbon product under high temperature, resulting in a decrease in carbon yield. Current research mainly optimizes technical parameters such as hydrothermal temperature, hydrothermal pressure, reaction time, and solid-liquid ratio to improve the efficiency of hydrothermal carbonization and inhibit the generation of by-products, or modifies the hydrothermal carbon product through physical or chemical modification methods to improve the quality of the hydrothermal carbon product. There are few studies on the development of hydrothermal carbonization intensification technology from the perspective of macrostructure and microstructure regulation of organic waste. Moreover, the current hydrothermal carbonization intensification technology consumes a large amount of energy or chemicals, limiting economic benefits. In addition, although the hydrothermal carbon product recovered after the hydrothermal carbonization treatment of organic waste has rich carbon, nitrogen, and phosphorus elements, meeting the requirements of soil conditioner, it still lacks the essential potassium element for plant growth. If potassium can be supplemented during the hydrothermal carbonization process of organic waste, the nutrient element composition distribution of the hydrothermal carbon product can be further enriched, and the quality of the soil conditioner can be improved.

[0005] In summary, from the perspective of waste treatment, waste is used as a strengthening measure to develop a technology that simultaneously modifies the macrostructure and microstructure of organic waste to improve the hydrothermal activity and contact mass transfer efficiency of organic waste, catalyze the hydrothermal reaction, improve the efficiency of hydrothermal carbonization, inhibit the generation of by-products, and supplement potassium. This is an urgent technical requirement at present, and there is currently no related technology. SUMMARY

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

[0007] To solve the technical problem, the technical scheme of the present application is: a method for strengthening hydrothermal carbonization of organic waste by coupling with grasswood ash and granulation, comprising the following steps:

[0008] S1: dehydrating or diluting the organic waste to adjust the moisture content of the organic waste to 80-90%, to obtain organic waste A with adjusted moisture content;

[0009] S2: Organic waste A is put into a macro / micro structure modification reactor, and organic waste A is cut and stirred at low speed using a multi-stage cutting agitator to initially break the structure of organic waste A and obtain non-uniform blocky organic waste B.

[0010] S3: High-frequency vibration fluidization of organic waste B is performed using a vibration fluidization device, while high-speed cutting and stirring of organic waste B is performed using a multi-stage cutting and stirring device. Through the combined effect of high-frequency vibration fluidization and high-speed cutting and stirring, organic waste B is transformed into a uniform small particle form, thereby modifying the macroscopic structure of organic waste B to obtain organic waste C with a uniform small particle form.

[0011] S4: Add alkaline wood ash to the macro / micro structure modification reactor. The amount of alkaline wood ash added is 0.25~1.25 g / g TS of organic waste C. The mixture is cut and stirred at low speed. At the same time, the organic waste C and alkaline wood ash are subjected to low-frequency vibration fluidization using a vibrating fluidization device. The alkaline wood ash promotes the alkaline decomposition of organic waste C and modifies the microstructure of organic waste C, resulting in a mixture D of organic waste C and alkaline wood ash. The pH of mixture D is 8.0~10.5.

[0012] S5: Add mixture D into a hydrothermal reactor and carry out a hydrothermal reaction at a temperature of 160~230℃ for 25~100min. At the same time, stir mixture D at a speed of 20~100rpm. During this process, the hydrothermal reactor is strictly sealed to maintain a saturated vapor pressure environment, and the hydrothermal carbonization reaction is completed to obtain hydrothermal carbonized mixed product E.

[0013] S6: Add the hydrothermal carbonization mixture E into a suspended percolation tank for solid-liquid separation to obtain hydrothermal carbon particles and hydrothermal liquid, respectively.

[0014] 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%.

[0015] S8: Collect hydrothermal carbon particles and put them into the cleaning tank to complete the cleaning of hydrothermal carbon particles. Then, discharge the cleaning water from the cleaning water outlet at the bottom of the cleaning tank. At the same time, use the filter screen set at the cleaning water outlet to trap the hydrothermal carbon particles.

[0016] S9: Collect the cleaned hydrothermal carbon particles, spread them out outdoors, and air dry them under sunlight for 6-24 hours to obtain dried hydrothermal carbon particles. Test the carbon, nitrogen, phosphorus, and potassium ratios and specific capacitance of the hydrothermal carbon particles. If they pass the test, collect them for use as a soil conditioner.

[0017] S10: Collect hydrothermal fluid from the bottom of the suspended infiltration tank and discharge it into the wastewater treatment system as a supplementary carbon source.

[0018] Preferably, the organic waste in S1 is one or more of dewatered sludge, fruit and vegetable waste, and garden waste;

[0019] When the moisture content of organic waste is <80%, add clean water to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is >90%, dehydrate the organic waste to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is 80-90%, step S1 is not required.

[0020] In step S2, a multi-stage cutting and stirring device is used to cut and stir organic waste A at low speed for 1 to 5 minutes, with the rotation speed set to 100 to 250 rpm.

[0021] Preferably, in step S3, the organic waste B is subjected to high-frequency vibration fluidization using a vibration fluidization device with a vibration frequency of 200~700 r / min, and the organic waste B is subjected to high-speed cutting and stirring using a multi-stage cutting and stirring device for 5~20 min with a rotation speed of 250~700 rpm.

[0022] When the organic waste is dewatered sludge, the speed of the multi-stage cutting mixer is set to 250~350 rpm, and the organic waste B is cut and mixed at high speed for 5~15 minutes. The average particle size of the organic waste C obtained is 3~20 mm.

[0023] When the organic waste is fruit and vegetable waste, the speed of the multi-stage cutting mixer is set to 350~500 rpm, and the organic waste B is cut and mixed at high speed for 5~20 minutes. The average particle size of the organic waste C obtained is 1~15 mm.

[0024] When the organic waste is landscaping waste, the speed of the multi-stage cutting mixer is set to 500~700 rpm, and the organic waste B is cut and mixed at high speed for 10~20 minutes. The resulting organic waste C has an average particle size of 1~15 mm.

[0025] Preferably, the alkaline wood ash used in S4 has a pH of 10.5~12 and a soluble K element content of ≥7%; the alkaline wood ash is added to the macro / micro structure modification reactor and stirred at a speed of 50~150 rpm for 1~3 min, while the organic waste C and alkaline wood ash are subjected to low-frequency vibration fluidization using a vibration fluidization device with a vibration frequency of 100~450 r / min.

[0026] Preferably, in step S4, alkaline wood ash is added and mixed with organic waste C to obtain mixture D. By adjusting the amount of alkaline wood ash added, the pH of mixture D is ensured to be 8.0~10.5.

[0027] When the organic waste is dewatered sludge, the pH of mixture D is 9.0~10.5;

[0028] When the organic waste is fruit and vegetable waste, the pH of mixture D is 8.5~10.0;

[0029] When the organic waste is landscaping waste, the pH of mixture D is 8.0~9.5.

[0030] Preferably, in step S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160~200℃ and the hydrothermal time is 25~50min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min; when the organic waste is garden and landscaping waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min.

[0031] In step S6, the hydrothermal carbonization mixture E is added into the suspended percolation tank. A suspended filter cloth is set 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 using a cloth plate. After standing for 1 to 12 hours, gravity percolation dewatering is achieved. The solids retained on the surface of the suspended filter cloth are hydrothermal carbon particles, and the hydrothermal liquid is percolated from the suspended filter cloth into the suspended percolation tank.

[0032] Preferably, in step S8, the hydrothermal carbon particles are added to a washing tank and stirred at a speed of 100-300 rpm for 0.5-2 hours, and the washing is repeated 1-5 times.

[0033] When the organic waste is dewatered sludge, the hydrothermal carbon granules are washed 3 to 5 times.

[0034] When the organic waste is fruit and vegetable waste, the hydrothermal charcoal granules are washed 2-4 times.

[0035] When the organic waste is landscaping waste, the hydrothermal carbon granules should be washed 1-3 times.

[0036] Preferably, the hydrothermal char particles dried in S9 are tested, and the hydrothermal char yield of dewatered sludge is ≥50%, the hydrothermal char yield of fruit and vegetable waste is ≥30%, and the hydrothermal char yield of garden greening waste is ≥60%.

[0037] The hydrothermal carbon content of dewatered sludge is ≥30%, the hydrothermal carbon content of fruit and vegetable waste is ≥55%, and the hydrothermal carbon content of landscaping waste is ≥60%.

[0038] The hydrothermal carbon and phosphorus content of dewatered sludge is ≥3%, that of fruit and vegetable waste is ≥0.15%, and that of landscaping waste is ≥0.2%.

[0039] The hydrothermal carbon and potassium content of dewatered sludge is ≥2%, that of fruit and vegetable waste is ≥2.5%, and that of landscaping waste is ≥1%.

[0040] The hydrothermal carbon specific capacitance of dewatered sludge is ≥1.8F / g, that of fruit and vegetable waste is ≥6.5F / g, and that of landscaping waste is ≥5F / g.

[0041] Preferably, an apparatus for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation is used to implement the above-mentioned method for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation. The apparatus includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended percolation module, a hydrothermal carbon particle cleaning module, a detection module, and a control component. The moisture content adjustment module, macro / micro structure modification module, hydrothermal carbonization reaction module, suspended percolation module, hydrothermal carbon particle cleaning module, and detection module are all electrically connected to the control component.

[0042] The moisture content adjustment module includes a moisture content adjustment tank and a dewatering machine. The moisture content adjustment tank is equipped with a first organic waste inlet, a water inlet, a first stirring device, and a first discharge outlet. The water inlet is connected to a water tank, and the dewatering machine is also equipped with a first discharge outlet.

[0043] The macro / micro structure modification module includes a first screw feeder and a macro / micro structure modification reactor. The macro / micro structure modification reactor has a built-in multi-stage cutting agitator and a vibrating fluidization device. The macro / micro structure modification reactor is also equipped with a second organic waste inlet, an alkaline wood ash inlet, and a second discharge outlet. The vibrating fluidization device is located at the bottom of the macro / micro structure modification reactor, and the solid metering feeding device is located at the top of the alkaline wood ash inlet. The bottom of the first screw feeder is connected to the first discharge outlet, and the top of the first screw feeder is connected to the second organic waste inlet.

[0044] The hydrothermal carbonization reaction module includes a second screw feeder and a hydrothermal reactor. The hydrothermal reactor has a built-in second stirring device and a heating and temperature control device. The hydrothermal reactor is also equipped with a mixture feeding port, a pressure monitoring device, a third discharge port, a pressure relief valve, and an explosion-proof plate. 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.

[0045] The suspended percolation module includes a feeding pump and a suspended percolation tank. An upper filter cloth support is set inside the suspended percolation tank, and a suspended filter cloth is placed on the upper filter cloth support. A cloth plate is provided on the surface of the suspended filter cloth, and the cloth plate is connected to a mechanical transmission machine. A hydrothermal liquid collection hopper, a hydrothermal liquid discharge pipe and valve are provided at the bottom of the suspended percolation tank. One end of the feeding pump is connected to the third discharge port, and the other end is connected to the top of the suspended filter cloth.

[0046] The hydrothermal carbon particle cleaning module includes a cleaning water storage tank and a cleaning pool. The cleaning pool has a built-in third stirring device, and the bottom of the cleaning pool is equipped with a filter screen and a cleaning water outlet. The cleaning water storage tank is connected to the cleaning pool.

[0047] The detection module includes a moisture content meter, an elemental analyzer, a capacitance tester, and a pH meter. The moisture content meter is used to detect the moisture content of organic waste A at the first discharge port and the hydrothermal carbon particles on the suspended filter cloth.

[0048] The pH meter is used to detect the pH of mixture D at the second outlet;

[0049] The moisture content meter, elemental analyzer, capacitance meter, and pH meter are also used to detect the property indicators of the hydrothermal carbon particles at the filter screen.

[0050] Preferably, the macro / micro structure modification reactor is a cylindrical reactor with a diameter-to-height ratio of 1:3 to 5:1. The multi-stage cutting agitator is equipped with three layers of spiral blades. The spacing between each layer of spiral blades is 1 / 7 to 1 / 4 of the 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 consist of three blades arranged at 120° intervals with a blade twist of 35° to 55°. The second layer of spiral blades consists of six blades arranged at 60° intervals with a blade twist of 25° to 45°. The length of each spiral blade is 1 / 4 to 2 / 5 of the inner diameter of the macro / micro structure modification reactor.

[0051] The suspended filter cloth has a mesh count of ≥200 mesh and the filter screen has a pore size of ≤0.1mm.

[0052] Compared with the prior art, the advantages of this application are:

[0053] (1) This application uses multi-stage cutting and stirring combined with vibration fluidization to perform macroscopic mechanical granulation of organic waste. While performing multi-stage cutting and stirring, the vibration fluidization effect of 200~700 r / min can maximize the efficiency of macroscopic structural modification and conversion of organic waste. The vibration fluidization effect can make the organic waste particles exhibit vibrational motion and semi-fluidized state in the macroscopic / microscopic structural modification reactor, providing better contact collision and cutting granulation conditions for cutting and stirring, and can efficiently realize the mechanical granulation function. Unlike the disordered crushing process of the macroscopic structure of organic waste in traditional crushing methods, the multi-stage cutting used in this application The combined treatment of stirring and vibration fluidization is an orderly crushing and granulation process of the macroscopic structure of organic waste. Instead of the irregular large pieces of organic waste produced by traditional crushing methods, it produces small organic waste particles with uniform particle size and regular shape. The resulting small particles of organic waste have the advantages of smaller particle size, more uniform particle size distribution, higher particle dispersion, and larger specific surface area. In the subsequent hydrothermal carbonization process, the hydrothermal mass transfer efficiency is high and the mass transfer is uniform, which helps to reduce the reaction temperature, reaction time and reaction pressure of hydrothermal carbonization, and improve the hydrothermal carbon yield and the physicochemical structure properties of hydrothermal carbon particles.

[0054] (2) This application utilizes alkaline wood ash for biomass microstructure modification treatment. Alkaline wood ash can play a long-term, continuous and stable alkaline destructive role, perform alkaline pre-destruction on the recalcitrant and recalcitrant organic matter in organic waste, improve its hydrothermal reactivity, reduce the reaction energy barrier of hydrothermal carbonization, help reduce the reaction temperature, reaction time and reaction pressure of hydrothermal carbonization, and improve the hydrothermal carbon yield and the physicochemical structure properties of hydrothermal carbon particles.

[0055] (3) This application utilizes a multi-stage cutting and stirring device to initially crush organic waste at a low speed of 100~250 rpm, breaking the organic waste into an uneven block shape; then, it is cut and crushed at a high speed of 250~700 rpm for 5~20 min, further converting the organic waste into a uniform small particle shape. Alkaline wood ash is added to the uniform small particle organic waste, and it is stirred at a low speed of 50~150 rpm for 1~3 min, while vibration fluidization is carried out to improve the uniformity of mixing between the uniform small particle organic waste and the alkaline wood ash. This multi-stage treatment process of low-speed crushing-high-speed cutting / vibration fluidization-low-speed mixing / vibration fluidization can effectively improve the macroscopic structure modification effect (improving granulation efficiency, particle uniformity and dispersion) and microscopic structure modification effect (reducing molecular helical tightness and improving hydrothermal reaction activity) of organic waste. Combined with the speed and time design of the multi-stage treatment process, it can play the best macroscopic / microscopic structure modification role of organic waste.

[0056] (4) This application utilizes alkaline wood ash coupled with multi-stage mechanical granulation to simultaneously modify and transform the macroscopic and microscopic structures of organic waste. This can exert a synergistic effect, improve the reaction mass transfer efficiency and biomass hydrothermal activity, thereby improving the hydrothermal carbonization efficiency of organic waste and significantly shortening the overall reaction time. At the same time, after alkaline wood ash coupled with multi-stage mechanical granulation, the macroscopic / microscopic structure of organic waste is modified and transformed, which promotes the acceleration and enhancement of the hydrothermal process. The hydrothermal reaction is more likely to occur fully, and hydrothermal carbonization can be completed at only 160~230℃. The reaction temperature is relatively low, and the saturated vapor pressure is also relatively low, resulting in milder reaction conditions and reduced engineering difficulty. In addition, after alkaline wood ash coupled with multi-stage mechanical granulation, the hydrothermal carbon particles recovered from the hydrothermal carbonization of organic waste 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 enhanced, 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.

[0057] (5) The alkaline wood ash used in this application contains abundant potassium, which can supplement the abundant carbon, nitrogen and phosphorus elements in the hydrothermal carbon product of organic waste, improve and enrich the nutrient element composition of the hydrothermal carbon product, and transform it into a high-quality soil conditioner with carbon fertilizer, nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer coexisting. The potassium content of the obtained hydrothermal carbon product is significantly higher than that of hydrothermal carbon or biochar obtained by traditional technology, which can improve the soil remediation effect of hydrothermal carbon product.

[0058] (6) This application uses a self-designed multi-stage cutting agitator to modify the macrostructure of organic waste. It is equipped with three layers of spiral blades. The spacing between the spiral blades in each layer is 1 / 7 to 1 / 4 of the effective height of the macro / micro structure modification reactor. The first and third layers of spiral blades are three blades arranged at 120° intervals with a blade twist of 35° to 55°. The second layer of spiral blades is six blades arranged at 60° intervals with a blade twist of 25° to 45°. The blade length is 1 / 4 to 2 / 5 of the effective inner diameter of the macro / micro structure modification reactor. The design of the blade arrangement layers, the number of blades in each layer, the arrangement angle, and the twist angle of the spiral blades in this application can improve the modification efficiency of the macrostructure of organic waste. Compared with the traditional crushing method, the organic waste particles after macrostructure modification using the multi-stage cutting agitator in this application have smaller particle sizes. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of a device for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation according to this application;

[0060] Figure 2This refers to the properties of the sludge hydrothermal carbon product in Example 1 of this application;

[0061] Figure 3 This is the property of the garden waste hydrothermal char product of Example 2 of this application;

[0062] Figure 4 This refers to the properties of the fruit and vegetable waste hydrothermal charcoal product from Example 3 of this application;

[0063] Figure 5 This is a process flow diagram of a method for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation, as described in this application.

[0064] Explanation of reference numerals in the attached figures:

[0065] 1-Moisture content adjustment tank; 2-First organic waste inlet; 3-Water inlet; 4-Water tank; 5-First stirring device; 6-First discharge outlet; 7-Dewatering machine; 8-First screw feeder; 9-Macro / microstructure modification reactor; 10-Multi-stage cutting stirrer; 11-Vibrating fluidization device; 12-Second organic waste inlet; 13-Solid metering and feeding device; 14-Alkaline wood ash inlet; 15-Second discharge outlet; 16-Second screw feeder; 17-Hydrothermal reactor; 18-Second stirring device; 19-Heating and temperature control device; 20-Mixed material feeding port; 21-Pressure monitoring device; 22-Third discharge port; 23-Pressure relief valve and explosion-proof plate; 24-Feeding pump; 25-Suspended percolation tank; 26-Upper filter cloth support; 27-Suspended filter cloth; 28-Material distribution plate; 29-Mechanical transmission machine; 30-Hydrothermal liquid collection hopper; 31-Hydrothermal liquid discharge pipe and valve; 32-Washing tank; 33-Third stirring device; 34-Filter screen; 35-Washing water discharge port; 36-Washing water storage tank; 37-Moisture content meter; 38-Elemental analyzer; 39-Capacitance tester; 40-pH meter. Detailed Implementation

[0066] The present application is described in detail below 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 spirit and scope of the present application. To provide the public with a thorough understanding of the present application, specific details are described in detail in the following embodiments, but those skilled in the art will fully understand the present application even without these detailed descriptions.

[0067] like Figure 1 , 5 As shown, this application discloses a method for enhanced hydrothermal carbonization of organic waste through plant ash coupling granulation, comprising the following steps:

[0068] S1: Dehydrate or dilute the organic waste with water to adjust the moisture content of the organic waste to 80-90% to obtain organic waste A with adjusted moisture content;

[0069] S2: Organic waste A is fed into macro / micro structure modification reactor 9, and organic waste A is cut and stirred at low speed using multi-stage cutting agitator 10 to initially break the structure of organic waste A and obtain uneven blocky organic waste B.

[0070] S3: The organic waste B is subjected to high-frequency vibration fluidization using the vibration fluidization device 11, and at the same time, the organic waste B is subjected to high-speed cutting and stirring using the multi-stage cutting and stirring device 10. Through the combined action of high-frequency vibration fluidization and high-speed 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 to obtain organic waste C with a uniform small particle form.

[0071] S4: Alkaline wood ash is added to the macro / micro structure modification reactor 9 at a dosage of 0.25~1.25 g / g TS organic waste C. The mixture is stirred, and at the same time, the organic waste C and alkaline wood ash are subjected to low-frequency vibration fluidization using the vibrating fluidization device 11. The alkaline wood ash is used to promote the alkaline decomposition of organic waste C and modify the microstructure of organic waste C, resulting in a mixture D of organic waste C and alkaline wood ash. The pH of mixture D is 8.0~10.5.

[0072] S5: Add mixture D into hydrothermal reactor 17 and carry out hydrothermal reaction at a temperature of 160~230℃ for 25~100min. At the same time, stir mixture D at a speed of 20~100rpm. During this process, hydrothermal reactor 17 is strictly sealed to maintain a saturated vapor pressure environment, and complete the hydrothermal carbonization reaction to obtain hydrothermal carbonized mixed product E.

[0073] S6: Add the hydrothermal carbonization mixture E into the suspended infiltration tank 25 for solid-liquid separation to obtain hydrothermal carbon particles and hydrothermal liquid, respectively.

[0074] 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%.

[0075] S8: Collect hydrothermal carbon particles and put them into the cleaning tank 32 to complete the cleaning of hydrothermal carbon particles. Then, discharge the cleaning water from the cleaning water outlet 35 at the bottom of the cleaning tank 32. At the same time, use the filter screen 34 set at the cleaning water outlet 35 to trap the hydrothermal carbon particles.

[0076] S9: Collect the cleaned hydrothermal carbon particles, spread them out outdoors, and air dry them under sunlight for 6-24 hours to obtain dried hydrothermal carbon particles. Test the carbon, nitrogen, phosphorus, and potassium ratios and specific capacitance of the hydrothermal carbon particles. If they pass the test, collect them for use as a soil conditioner.

[0077] S10: Collect hydrothermal fluid from the bottom of the suspended infiltration tank 25 and discharge it into the wastewater treatment system as a supplementary carbon source.

[0078] Preferably, the organic waste in S1 is one or more of dewatered sludge, fruit and vegetable waste, and garden waste;

[0079] When the moisture content of organic waste is <80%, add clean water to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is >90%, dehydrate the organic waste to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is 80-90%, step S1 is not required.

[0080] In step S2, the multi-stage cutting and stirring device 10 is used to cut and stir the organic waste A at low speed for 1 to 5 minutes, with the rotation speed set to 100 to 250 rpm.

[0081] Preferably, in step S3, the organic waste B is subjected to high-frequency vibration fluidization using the vibration fluidization device 11, with a vibration frequency of 200~700 r / min, and the organic waste B is subjected to high-speed cutting and stirring using the multi-stage cutting and stirring device 10 for 5~20 min, with a rotation speed of 250~700 rpm.

[0082] When the organic waste is dewatered sludge, the speed of the multi-stage cutting agitator 10 is set to 250~350 rpm, and the organic waste B is cut and stirred at high speed for 5~15 minutes, and the average particle size of the organic waste C obtained is 3~20 mm.

[0083] When the organic waste is fruit and vegetable waste, the speed of the multi-stage cutting and mixing machine 10 is set to 350~500 rpm, and the organic waste B is cut and mixed at high speed for 5~20 minutes. The average particle size of the organic waste C obtained is 1~15 mm.

[0084] When the organic waste is landscaping waste, the speed of the multi-stage cutting mixer 10 is set to 500~700 rpm, and the organic waste B is cut and mixed at high speed for 10~20 minutes, and the average particle size of the organic waste C obtained is 1~15 mm.

[0085] Preferably, the alkaline wood ash used in S4 has a pH of 10.5~12 and a soluble K element content of ≥7%; the alkaline wood ash is added to the macro / micro structure modification reactor 9 and stirred at a speed of 50~150 rpm for 1~3 min, while the organic waste C and alkaline wood ash are subjected to low-frequency vibration fluidization using a vibration fluidization device 11 with a vibration frequency of 100~450 r / min.

[0086] Preferably, in step S4, alkaline wood ash is added and mixed with organic waste C to obtain mixture D. By adjusting the amount of alkaline wood ash added, the pH of mixture D is ensured to be 8.0~10.5.

[0087] When the organic waste is dewatered sludge, the pH of mixture D is 9.0~10.5;

[0088] When the organic waste is fruit and vegetable waste, the pH of mixture D is 8.5~10.0;

[0089] When the organic waste is landscaping waste, the pH of mixture D is 8.0~9.5.

[0090] Preferably, in step S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160~200℃ and the hydrothermal time is 25~50min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min; when the organic waste is garden and landscaping waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min.

[0091] In step S6, the hydrothermal carbonization mixture E is added into the suspended percolation tank 25. A suspended filter cloth 27 is set 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 using the cloth plate 28. After standing for 1 to 12 hours, gravity percolation dewatering is achieved. The solids retained on the surface of the suspended filter cloth 27 are hydrothermal carbon particles. The hydrothermal liquid is percolated from the suspended filter cloth 27 into the suspended percolation tank 25.

[0092] Preferably, in step S8, the hydrothermal carbon particles are added to the washing tank 32 and stirred at a speed of 100-300 rpm for 0.5-2 hours, and the washing is repeated 1-5 times.

[0093] When the organic waste is dewatered sludge, the hydrothermal carbon granules are washed 3 to 5 times.

[0094] When the organic waste is fruit and vegetable waste, the hydrothermal charcoal granules are washed 2-4 times.

[0095] When the organic waste is landscaping waste, the hydrothermal carbon granules should be washed 1-3 times.

[0096] Preferably, the hydrothermal char particles dried in S9 are tested, and the hydrothermal char yield of dewatered sludge is ≥50%, the hydrothermal char yield of fruit and vegetable waste is ≥30%, and the hydrothermal char yield of garden greening waste is ≥60%.

[0097] The hydrothermal carbon content of dewatered sludge is ≥30%, the hydrothermal carbon content of fruit and vegetable waste is ≥55%, and the hydrothermal carbon content of landscaping waste is ≥60%.

[0098] The hydrothermal carbon and phosphorus content of dewatered sludge is ≥3%, that of fruit and vegetable waste is ≥0.15%, and that of landscaping waste is ≥0.2%.

[0099] The hydrothermal carbon and potassium content of dewatered sludge is ≥2%, that of fruit and vegetable waste is ≥2.5%, and that of landscaping waste is ≥1%.

[0100] The hydrothermal carbon specific capacitance of dewatered sludge is ≥1.8F / g, that of fruit and vegetable waste is ≥6.5F / g, and that of landscaping waste is ≥5F / g.

[0101] Preferably, an apparatus for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation is used to implement the above-mentioned method for enhancing the hydrothermal carbonization of organic waste through plant ash coupling granulation. The apparatus includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended percolation module, a hydrothermal carbon particle cleaning module, a detection module, and a control component. The moisture content adjustment module, macro / micro structure modification module, hydrothermal carbonization reaction module, suspended percolation module, hydrothermal carbon particle cleaning module, and detection module are all electrically connected to the control component.

[0102] The moisture content adjustment module includes a moisture content adjustment tank 1 and a dewatering machine 7. The moisture content adjustment tank 1 is provided with a first organic waste inlet 2, a water inlet 3, a first stirring device 5 and a first discharge outlet 6. The water inlet 3 is connected to a water tank 4. The dewatering machine 7 is also provided with a first discharge outlet 6.

[0103] 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 has a built-in multi-stage cutting agitator 10 and a vibrating fluidization device 11. The macro / micro structure modification reactor 9 is also provided with a second organic waste inlet 12, an alkaline wood ash inlet 14 and a second discharge outlet 15. The vibrating fluidization device 11 is located at the bottom of the macro / micro structure modification reactor 9, and the solid metering feeding device 13 is located at the top of the alkaline wood ash inlet 14. The bottom of the first screw feeder 8 is connected to the first discharge outlet 6, and the top of the first screw feeder 8 is connected to the second organic waste inlet 12.

[0104] The hydrothermal carbonization reaction module includes a second screw feeder 16 and a hydrothermal reactor 17. The hydrothermal reactor 17 has a built-in second stirring device 18 and a heating and temperature control device 19. The hydrothermal reactor 17 is also equipped with a mixture feeding port 20, a pressure monitoring device 21, a third discharge port 22, a pressure relief valve, and an explosion-proof plate 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.

[0105] The suspended percolation module includes a feeding pump 24 and a suspended percolation tank 25. An upper filter cloth support 26 is set inside the suspended percolation tank 25. A suspended filter cloth 27 is placed on the upper filter cloth support 26. A cloth plate 28 is provided on the surface of the suspended filter cloth 27. The cloth plate 28 is connected to a mechanical transmission 29. A hydrothermal liquid collection hopper 30 and a hydrothermal liquid discharge pipe and valve 31 are provided at the bottom of the suspended percolation tank 25. One end of the feeding 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.

[0106] The hydrothermal carbon particle cleaning module includes a cleaning water storage tank 36 and a cleaning pool 32. The cleaning pool 32 has a built-in third stirring device 33. The bottom of the cleaning pool 32 is provided with a filter screen 34 and a cleaning water outlet 35. The cleaning water storage tank 36 is connected to the cleaning pool 32.

[0107] The detection module includes a moisture content meter 37, an elemental analyzer 38, a capacitance tester 39, and a pH meter 40. The moisture content meter 37 is used to detect the moisture content of organic waste A at the first discharge port 6 and the hydrothermal carbon particles on the suspended filter cloth 27.

[0108] The pH meter 40 is used to detect the pH of mixture D at the second outlet 15;

[0109] The moisture content meter 37, elemental analyzer 38, capacitance meter 39, and pH meter 40 are also used to detect the property indicators of the hydrothermal carbon particles at filter screen 34.

[0110] Preferably, the macro / micro structure modification reactor 9 is a cylindrical reactor with a diameter-to-height ratio of 1:3 to 5:1. The multi-stage cutting agitator 10 is equipped with three layers of spiral blades. The spacing between each layer of spiral blades is 1 / 7 to 1 / 4 of the height of the macro / micro structure modification reactor 9. The spiral blades are distributed blades made of stainless steel. The first and third layers of spiral blades are three blades arranged at 120° intervals with a blade twist of 35° to 55°. The second layer of spiral blades is six blades arranged at 60° intervals with a blade twist of 25° to 45°. The length of each spiral blade is 1 / 4 to 2 / 5 of the inner diameter of the macro / micro structure modification reactor 9.

[0111] The suspended filter cloth 27 has a mesh count ≥ 200 mesh, and the filter screen 34 has a pore size ≤ 0.1 mm.

[0112] This application utilizes alkaline wood ash coupled with multi-stage mechanical granulation to treat organic waste. Due to the synergistic effect of multi-stage mechanical granulation promoting macroscopic structural modification of organic waste and alkaline wood ash inducing microscopic structural modification of organic matter, the overall mass transfer efficiency and hydrothermal activity are improved. This can promote the hydrothermal reaction to tend towards inorganic carbonization reaction, reduce the generation of by-products such as odor and oil, and ultimately result in a lower by-product content than similar technologies.

[0113] This application utilizes alkaline wood ash to first pre-decompose organic waste using alkaline methods, modifying its microstructure. It then increases potassium content, improving the quality of the hydrothermal carbon particles. Unlike traditional methods that add wood ash during the dewatering stage of organic waste (sludge, etc.), this application adds alkaline wood ash after the organic waste moisture content adjustment (S1 step), pre-crushing (S2 step), and multi-stage mechanical granulation (S3 step, i.e., macrostructure modification). The alkaline wood ash is mixed with organic waste with a moisture content of 80-90% and a uniform small particle macrostructure. The mixture is then immediately fed into a hydrothermal reactor for hydrothermal carbonization. This method of adding alkaline wood ash and the process flow have [advantages / advantages]. The advantages of alkaline wood ash include no loss (unlike traditional addition methods where alkaline wood ash is lost during dehydration and discharged with the filtrate), increased potassium content in the product, sustained effect (gradually dissolving and reacting with organic molecules during hydrothermal carbonization, unlike the rapid dissolution and short-term reaction of traditional addition methods), and catalytic action during hydrothermal carbonization (the mixture is immediately added to the hydrothermal reactor after uniform mixing, thus participating in the hydrothermal carbonization process). These advantages help reduce the reaction temperature, reaction time, and reaction pressure of hydrothermal carbonization, and improve the hydrothermal carbon yield and the physicochemical properties of hydrothermal carbon particles.

[0114] The order in which wood ash is added affects the treatment purpose. In existing technologies, wood ash is added to condition sludge and improve its dewatering properties, which is unrelated to the pyrolysis and carbonization process. In this application, wood ash is added to perform alkaline hydrolysis, modify and optimize the microstructure of organic matter (especially useful for the microstructure modification of biomass by wood ash, which is particularly effective for garden waste and agricultural and forestry waste, which contain a lot of cellulose), and also to catalyze hydrothermal reaction activity.

[0115] The alkaline wood ash used in this application is an agricultural and forestry waste, which has the benefit of "treating waste with waste". Apart from this, no other chemical agents are used in this application. Compared with other technologies that add a variety of coagulants, additives, conditioners and other chemical agents, 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, which has low energy consumption and low processing cost. After the alkaline wood ash coupled with multi-stage mechanical granulation treatment, the temperature required for hydrothermal carbonization of organic waste is reduced, the saturated vapor pressure is reduced, and the reaction time is shortened, and the energy consumption of hydrothermal reaction is greatly reduced, which has the advantages of economic and energy saving. Therefore, the overall economic benefits of this application are significant and superior to similar technologies.

[0116] This application proposes detailed implementation methods, operating modes, and technical parameters for different organic wastes based on their component structure characteristics. It can be adapted to various organic wastes such as residual sludge, fruit and vegetable waste, and garden greening waste, and can flexibly match organic wastes of different properties. The invention has good flexibility and stability in implementation and operation.

[0117] Example 1

[0118] This embodiment provides a method for enhancing the hydrothermal carbonization of organic waste and the recovery of potassium-rich soil conditioner by coupling alkaline wood ash with multi-stage mechanical granulation, including the following specific steps:

[0119] S1, when the moisture content of the dewatered sludge is <80%, the dewatered sludge is added into the moisture content adjustment tank 1 through the first organic waste inlet 2, and clean water is injected through the water tank 4 and the water inlet 3. The dewatered sludge and clean water are mixed and stirred by the first stirring device 5 to obtain organic waste A after adjusting the moisture content. The moisture content of organic waste A is detected by the moisture content detector 37, and the amount of clean water injected is adjusted until the moisture content of organic waste A is 80~90%. Organic waste A is discharged from the first discharge outlet 6.

[0120] S2, using the first screw feeder 8, organic waste A is added into the macro / micro structure modification reactor 9 from the second organic waste inlet 12. The organic waste A is then cut and stirred at low speed for 1-5 minutes using the multi-stage cutting and stirring agitator 10, with the speed set to 100-250 rpm, to initially break down the structure of organic waste A and obtain uneven blocky organic waste B.

[0121] S3, turn on the vibration fluidization device 11, and perform high-frequency vibration fluidization on organic waste B at a vibration frequency of 200~700r / min. At the same time, change the rotation speed of the multi-stage cutting agitator 10 to 250~700rpm. Under high-speed cutting and stirring conditions, use the multi-stage cutting agitator 10 to perform high-speed cutting and stirring on organic waste B for 5~15min. Through the combined action of vibration fluidization and multi-stage mechanical cutting and stirring, organic waste B is transformed into a uniform small particle shape, thereby modifying the macroscopic structure of organic waste B and realizing multi-stage mechanical granulation of organic waste to obtain organic waste C with a uniform small particle shape. The average particle size of the obtained organic waste C is 3~20mm.

[0122] S4. Alkaline wood ash with a pH of 10.5-12 and a soluble potassium content ≥7% is added to the macro / micro structure modification reactor 9 through the solid metering feeding device 13 and the alkaline wood ash feeding port 14. The amount of alkaline wood ash added is 0.25-1.25 g / g. Organic waste C (TS) is stirred for 1-3 minutes at a low speed of 50-150 rpm using a multi-stage cutting mixer 10. Simultaneously, a vibrating fluidization device is used to perform low-frequency vibration fluidization of organic waste C and alkaline wood ash at a vibration frequency of 100-450 rpm to improve the mixing uniformity of organic waste C and alkaline wood ash. The alkaline wood ash promotes alkaline decomposition of organic waste C, modifying the microstructure of organic waste C, resulting in a mixture D of organic waste C and alkaline wood ash. The pH value of mixture D is measured using a pH meter 40 and is 9.0-10.5. If it does not meet the requirements, the amount of alkaline wood ash added should be changed and step S4 should be repeated. Then, mixture D is discharged from the second discharge port 15.

[0123] S5, using the second screw feeder 16, the mixture D is fed into the hydrothermal reactor 17 from the mixture feeding port 20. The heating and temperature control device 19 ensures that the hydrothermal reaction is carried out at a temperature of 170~200℃ for 25~50 minutes. At the same time, the second stirring device 18 stirs the mixture D at a speed of 20~100 rpm. During this process, the hydrothermal reactor is strictly sealed. 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℃, the pressure relief valve and explosion-proof plate 23 are opened to release the pressure, and the hydrothermal carbonization mixture product E is obtained and discharged from the third discharge port 22.

[0124] S6, the hydrothermal carbonization mixture E is added into the suspended percolation tank 25 using the feed pump 24. The upper layer of the suspended percolation tank is equipped with an upper filter cloth support 26 and a suspended filter cloth 27. The hydrothermal carbonization mixture E is evenly spread on the surface of the suspended filter cloth 27 using the metal cloth plate 28 and the mechanical transmission machine 29. After standing for 1~12 hours, gravity percolation dewatering is achieved. The solids retained on the surface of the suspended filter cloth are hydrothermal carbon particles. The hydrothermal liquid is percolated from the suspended filter cloth into the suspended percolation tank 25.

[0125] S7. Use a moisture meter 37 to 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 step S6 until the moisture content is ≤40%.

[0126] S8. Collect hydrothermal carbon particles from the surface of the suspended filter cloth 27 and put them into the washing tank 32. Pour clean water into the washing tank 32 from the washing storage tank 36. Stir the water at a speed of 100~300 rpm for 0.5~2 hours using the third stirring device 33. Repeat the washing 3~5 times to complete the washing of hydrothermal carbon particles. Then discharge the washing water from the washing water outlet 35 at the bottom of the washing tank 32. At the same time, use the filter screen 34 set at the washing water outlet 35 to trap the hydrothermal carbon particles.

[0127] S9. Collect the washed hydrothermal char particles, spread them out outdoors, and air-dry them under sunlight for 6-24 hours to obtain dry hydrothermal char particles. Use a moisture content meter 37, an elemental analyzer 38, a capacitance tester 39, and a pH meter 40 to test the properties of the hydrothermal char particles. The hydrothermal char yield ≥50%, the carbon content ≥30%, the phosphorus content ≥3%, the potassium content ≥2%, and the specific capacitance ≥1.8F / g. If the above requirements are not met, mix them with organic waste C and repeat steps S4-S9 until the above requirements are met. Collect the dry hydrothermal char for use as a soil conditioner.

[0128] S10, hydrothermal liquid is collected from the hydrothermal liquid collection hopper 30 at the bottom of the suspended infiltration tank 25 and discharged into the sewage treatment system as a supplementary carbon source through the hydrothermal liquid discharge pipe and valve 31.

[0129] Example 2

[0130] The difference between this embodiment and Embodiment 1 is that the organic waste being treated is fruit and vegetable waste with a moisture content of <80%. In step S3, the multi-stage cutting and stirring speed is 350~500 rpm, the cutting and stirring time is 5~20 min, and the average particle size of the resulting organic waste C should be 1~15 mm. In step S4, the pH of the mixture D should be 8.5~10.0. In step S5, the hydrothermal temperature should be 200~230℃, and the hydrothermal treatment time should be 40~100 min. In step S8, the number of times the hydrothermal carbon particles are washed should be 2~4 times. In step S9, the properties of the hydrothermal carbon particles should meet the following requirements: hydrothermal carbon yield ≥30%, hydrothermal carbon carbon content ≥55%, hydrothermal carbon phosphorus content ≥0.15%, hydrothermal carbon potassium content ≥2.5%, and hydrothermal carbon specific capacitance ≥6.5 F / g.

[0131] Example 3

[0132] The difference between this embodiment and Embodiment 1 is that the organic waste being treated is landscaping waste with a moisture content of <80%. In step S3, the multi-stage cutting and stirring speed is 500~700 rpm, the cutting and stirring time is 10~20 min, and the average particle size of the resulting organic waste C is 1~15 mm. In step S4, the pH of the mixture D should be 8.0~9.5. In step S5, the hydrothermal temperature should be 200~230℃, and the hydrothermal treatment time should be 40~100 min. In step S8, the number of times the hydrothermal carbon particles are washed should be 1~3 times. In step S9, the properties of the hydrothermal carbon particles should meet the following requirements: hydrothermal carbon yield ≥60%, hydrothermal carbon carbon content ≥60%, hydrothermal carbon phosphorus content ≥0.2%, hydrothermal carbon potassium content ≥1%, and hydrothermal carbon specific capacitance ≥5 F / g.

[0133] Example 4

[0134] The difference between this embodiment and Embodiment 1 is that the water content of the dewatered sludge being treated is 80-90%, so step S1 is not required.

[0135] Example 5

[0136] The difference between this embodiment and embodiment 1 is that the moisture content of the dewatered sludge is >90%, and step S1 is changed to adding the dewatered sludge into the dewatering machine 7 for secondary dewatering to obtain organic waste A with adjusted moisture content. The moisture content of organic waste A is detected by the moisture content detector 37, and the operating parameters of the dewatering machine, such as pressure and time, are adjusted until the moisture content of organic waste A is 80~90%, and organic waste A is discharged from the first discharge port 6.

[0137] Example 6

[0138] The difference between this embodiment and embodiment 2 is that the moisture content of the processed fruit and vegetable waste is 80-90%, so step S1 is not required.

[0139] Example 7

[0140] The difference between this embodiment and embodiment 2 is that the moisture content of the processed fruit and vegetable waste is >90%. Step S1 is changed to adding the fruit and vegetable waste into the dehydrator 7 for secondary dehydration to obtain organic waste A with adjusted moisture content. The moisture content of organic waste A is detected by the moisture content detector 37. The operating parameters of the dehydrator, such as pressure and time, are adjusted until the moisture content of organic waste A is 80~90%. Organic waste A is then discharged from the first discharge port 6.

[0141] Example 8

[0142] The difference between this embodiment and embodiment 3 is that the water content of the garden waste being treated is 80-90%, so step S1 is not required.

[0143] Example 9

[0144] The difference between this embodiment and embodiment 3 is that the moisture content of the treated garden waste is >90%. Step S1 is changed to adding the garden waste into the dewatering machine 7 for secondary dewatering to obtain organic waste A with adjusted moisture content. The moisture content of organic waste A is detected by the moisture content detector 37. The operating parameters of the dewatering machine, such as pressure and time, are adjusted until the moisture content of organic waste A is 80~90%. Organic waste A is then discharged from the first discharge port 6.

[0145] Example 10

[0146] like Figure 4 As shown, this application discloses a method for enhanced hydrothermal carbonization of organic waste through plant ash coupling granulation, comprising the following steps:

[0147] S1: Moisture content adjustment, using dilution or dehydration methods;

[0148] S2: Initial crushing, using a low-speed cutting and stirring method;

[0149] S3: Multi-stage mechanical granulation, high-frequency vibration fluidization + high-speed cutting and stirring;

[0150] S4: Alkaline wood ash treatment, low-frequency vibration fluidization + low-speed cutting and stirring;

[0151] S5: Hydrothermal carbonization

[0152] S6: Suspended percolation to obtain hydrothermal carbon particles and hydrothermal liquid;

[0153] S7: Moisture content test. 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%.

[0154] S8: Hydrothermal carbon cleaning;

[0155] S9: Natural drying; Hydrothermal carbon property test: If it meets the standard, it can be used as a high-quality potassium-rich soil conditioner; if it does not meet the standard, repeat S4.

[0156] S10: Hydrothermal fluid is collected and discharged for use as a supplementary carbon source.

[0157] Application Example 1

[0158] Dewatered sludge is obtained from a wastewater treatment plant. The moisture content of the dewatered sludge is measured to be 85% using a moisture content meter 37. 1L of dewatered sludge is fed into the macro / micro structure modification reactor 9 through the second organic waste inlet 12 using the first screw feeder 8. The diameter:height ratio 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 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 consist of three blades spaced at 120° intervals with a blade twist of 45°. The second layer of spiral blades consists of six blades spaced at 60° intervals with a blade twist of 30°. The length of each blade 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 using a multi-stage cutting agitator 10 at a speed of 200 rpm, initially breaking down the structure of the dewatered sludge to obtain non-uniform blocky dewatered sludge B. Then, the vibrating fluidization device 11 was activated to vibrate and fluidize the dewatered sludge B at a vibration frequency of 500 rpm. Simultaneously, the speed of the multi-stage cutting agitator 10 was changed to 350 rpm. Under high-speed cutting and stirring conditions, the dewatered sludge B was cut and stirred for 10 minutes using the multi-stage cutting agitator 10. Through the combined action of vibrating fluidization and multi-stage mechanical cutting and stirring, the dewatered sludge B was transformed into uniform small particles, thereby modifying the macroscopic structure of the dewatered sludge B and achieving multi-stage mechanical granulation of organic waste to obtain dewatered sludge C with a uniform small particle shape. The average particle size of the obtained dewatered sludge C particles was 15 mm. Alkaline wood ash with a pH of 11.0 and a soluble potassium content of 9% was added to the macro / microstructure modification reactor 9 through a solid metering feeding device 13 and an alkaline wood ash feeding port 14. The amount of alkaline wood ash added was 1.0 g / g TS sludge. The mixture was stirred for 3 min at a low speed of 100 rpm using a multi-stage cutting agitator 10. At the same time, the dewatered sludge C and alkaline wood ash were vibrated and fluidized at a vibration frequency of 300 r / min using a vibrating fluidization device to improve the mixing uniformity of the dewatered sludge C particles and alkaline wood ash. The alkaline wood ash promoted the alkaline decomposition of the dewatered sludge C particles, modifying the microstructure of the dewatered sludge C particles, resulting in a mixture D of dewatered sludge C particles and alkaline wood ash. The pH value of mixture D was measured to be 10.0 using a pH meter 40.Then, mixture D is discharged from the second outlet 15 and 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 180℃ for 30 minutes using the heating and temperature control device 19, while the mixture D is stirred at 100 rpm using the second stirring device 18. During this process, the hydrothermal reactor is strictly sealed, and the pressure is monitored using 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℃, the pressure relief valve and explosion-proof plate 23 are opened to release the pressure, obtaining the hydrothermal carbonization mixture E, which is discharged from the third outlet 22. The hydrothermal carbonization mixture E is then fed into the suspended percolation tank 25 using the feed pump 24. The suspended percolation tank is 6m long and 2m wide, with an upper filter cloth support 2 installed on the upper layer. 6. A suspended filter cloth 27, the same size as the suspended filter tank, with a mesh size of 250, is provided. The hydrothermal carbonization mixture is evenly spread on the surface of the suspended filter cloth 27 using a metal cloth plate 28 and a mechanical transmission machine 29. After standing for 10 hours, gravity infiltration dewatering is achieved. The solids retained on the surface of the suspended filter cloth are the sludge hydrothermal carbon particles. The hydrothermal liquid that seeps from the suspended filter cloth into the suspended infiltration tank is the hydrothermal liquid. The moisture content of the hydrothermal carbon particles is measured to be 20% using a moisture content meter 37. The hydrothermal carbon particles are collected from the surface of the suspended filter cloth and put into the washing tank 32. Clean water is injected into the washing tank from the washing storage tank 36. The third stirring device 33 is used to stir at a speed of 300 rpm for 1 hour. The washing is repeated 5 times to complete the washing of the hydrothermal carbon particles. Then the washing water is discharged from the washing water outlet 35 at the bottom of the washing water tank. At the same time, the hydrothermal carbon particles are retained by the filter screen 34 set at the outlet. The filter screen has a pore size of 0.08 mm. The cleaned hydrothermal carbon particles were collected, laid flat outdoors, and air-dried under sunlight for 18 hours to obtain dried sludge hydrothermal carbon particles. The properties of the sludge hydrothermal carbon particles were tested using an elemental analyzer 38 and a capacitance tester 39, and the results are as follows. Figure 2 As shown: the hydrothermal carbon yield was 54.54%, higher than the 38.45% of the control group treated by traditional hydrothermal carbonization; the carbon content of the hydrothermal carbon product was 31.15%, higher than the 26.53% of the control group; the phosphorus content of the hydrothermal carbon product was 3.5%, higher than the 3.477% of the control group; the potassium content of the hydrothermal carbon product was 2.668%, higher than the 0.018% of the control group, mainly due to the introduction of a large amount of potassium into the sludge hydrothermal carbon by alkaline wood ash; the specific capacitance of the hydrothermal carbon product was 2.027 F / g, higher than the 1.333 F / g of the control group, indicating better electrochemical properties. The above-mentioned hydrothermal carbon particle properties meet the requirements, and the collected dried sludge hydrothermal carbon is used as a soil conditioner. Simultaneously, hydrothermal liquid is collected from the hydrothermal liquid collection hopper 30 at the bottom of the suspended infiltration tank 25 and discharged into the wastewater treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0159] Application Example 2

[0160] Garden waste is collected from urban parks and gardens. The moisture content of the garden waste is measured to be 20% using a moisture content meter 37. The garden waste is then added to the moisture content adjustment tank 1 through the first organic waste inlet 2. Clean water is injected through the water tank 4 and water inlet 3. The garden waste and clean water are mixed using the first stirring device 5 to obtain garden waste A with adjusted moisture content. The moisture content of the garden waste is measured to be 85% using the moisture content meter 37. Garden waste A is then discharged from the first discharge outlet 6. One liter of the adjusted garden waste is then fed through the second organic waste inlet 12 using the first screw feeder 8. The waste A was added to the macro / micro structure modification reactor 9, which has a diameter-to-height ratio of 1:1. It features a built-in multi-stage cutting agitator with three layers of spiral blades. The blade spacing in each layer is 1 / 5 of the effective height of the macro / micro structure modification reactor. The spiral blades are distributed stainless steel blades. The first and third layers consist of three blades spaced at 120° intervals with a 45° twist. The second layer consists of six blades spaced at 60° intervals with a 30° twist. The blade length is 1 / 3 of the effective inner diameter of the macro / micro structure modification reactor. The multi-stage cutting agitator 10 was used to cut and agitate the garden waste A for 5 minutes at a speed of 200 rpm, initially breaking down the structure of the garden waste A to obtain uneven, blocky garden waste B.Subsequently, the vibrating fluidization device 11 was activated to vibrate and fluidize the garden waste B at a vibration frequency of 500 r / min. Simultaneously, the rotation speed of the multi-stage cutting agitator 10 was changed to 700 rpm. Under high-speed cutting and stirring conditions, the garden waste B was cut and stirred for 15 minutes using the multi-stage cutting agitator 10. Through the combined action of vibrating fluidization and multi-stage mechanical cutting and stirring, the garden waste B was transformed into uniform small particles, thereby modifying the macroscopic structure of the garden waste B and achieving multi-stage mechanical granulation of organic waste to obtain garden waste C with uniform small particle shape. The average particle size of the obtained garden waste C particles should be 8 mm. Alkaline wood ash with a pH of 11 and a soluble potassium content of 9% was added to 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 was 0.8 g / g. TS landscaping waste was mixed with alkaline wood ash using a multi-stage cutting mixer 10 at a low speed of 100 rpm for 3 minutes. Simultaneously, a vibrating fluidization device was used to vibrate and fluidize the landscaping waste C particles and alkaline wood ash at a vibration frequency of 350 rpm, improving the mixing uniformity of the landscaping waste C particles and alkaline wood ash. The alkaline wood ash promoted alkaline decomposition of the landscaping waste C particles, modifying their microstructure, resulting in a mixture D of landscaping waste C particles and alkaline wood ash. The pH value of the mixture was measured to be 9.0 using a pH meter 40. Mixture D was then discharged from the second outlet 15. A second screw feeder 16 fed mixture D into a hydrothermal reactor 17 through a mixing inlet 20. The hydrothermal reaction was carried out at 220℃ for 60 minutes using a heating and temperature control device 19, while a second stirring device 18 stirred mixture D at a speed of 100 rpm. During the process, the hydrothermal reactor is strictly sealed, and the pressure is monitored using a 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℃, the pressure relief valve and explosion-proof diaphragm 23 are opened to release the pressure, resulting in a hydrothermal carbonization mixture E. This mixture is discharged from the third outlet 22 and fed into a suspended infiltration tank 25 using a feed pump 24. The suspended infiltration tank is 6m long and 2m wide, with a safety device installed on the upper layer of the tank. A filter cloth support 26 is installed, and a suspended filter cloth 27 of the same size as the suspended filter tank is provided. The suspended filter cloth has a mesh size of 250 mesh. The hydrothermal carbonization mixture is evenly spread on the surface of the suspended filter cloth 27 using a metal cloth plate 28 and a mechanical transmission machine 29. After standing for 8 hours, gravity infiltration dewatering is achieved. The solids retained on the surface of the suspended filter cloth are the hydrothermal carbon particles for landscaping. The hydrothermal liquid is the product that seeps from the suspended filter cloth into the suspended infiltration tank. The moisture content of the hydrothermal carbon particles is 20% as measured by a moisture content meter 37.Hydrothermal carbon particles are collected from the surface of the suspended filter cloth and placed into the washing tank 32. Clean water is injected into the washing tank from the washing storage tank 36. The third stirring device 33 is used to stir the particles at a speed of 300 rpm for 1 hour. The washing process is repeated twice to complete the washing of the hydrothermal carbon particles. Then, the washing water is discharged from the washing water outlet 35 at the bottom of the washing tank. At the same time, the hydrothermal carbon particles are trapped by the filter screen 34 set at the outlet. The filter screen has a pore size of 0.08 mm. The washed hydrothermal carbon particles are collected and laid flat outdoors to air dry under sunlight for 24 hours to obtain dried garden hydrothermal carbon particles. The properties of the garden hydrothermal carbon particles are tested using an elemental analyzer 38 and a capacitance tester 39. The results are as follows. Figure 3 As shown: the hydrothermal char yield was 68.82%, higher than the 62.52% of the control group treated with traditional hydrothermal carbonization; the carbon content of the hydrothermal char product was 64.89%, higher than the 44.12% of the control group; the phosphorus content of the hydrothermal char product was 0.207%, higher than the 0.198% of the control group; the potassium content of the hydrothermal char product was 1.66%, higher than the 0.04% of the control group, mainly due to the introduction of a large amount of potassium into the garden hydrothermal char by alkaline wood ash; the specific capacitance of the hydrothermal char product was 5.10 F / g, higher than the 3.34 F / g of the control group, indicating better electrochemical properties. The above-mentioned properties of the hydrothermal char particles meet the requirements, and the collected and dried garden hydrothermal char particles are used as a soil conditioner. Simultaneously, hydrothermal liquid is collected from the hydrothermal liquid collection hopper 30 at the bottom of the suspended infiltration tank 25 and discharged into the wastewater treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0161] Application Example 3

[0162] Fruit and vegetable waste was collected from residential areas. The moisture content of the waste, measured by a moisture meter 37, was 96%. The waste was then fed into a dehydrator 7 for secondary dehydration. The dehydrator's operating pressure was adjusted, and dehydration was carried out for 20 minutes, resulting in adjusted moisture content waste. The moisture content of this waste, measured by the moisture meter 37, was 86%. The waste was discharged from the first outlet 6. Using a first screw feeder 8, 1L of the waste was fed into the macro / micro structure modification reactor 9 through the second organic waste inlet 12. Macro / micro structure modification... The reactor 9 has a diameter-to-height ratio of 1:1 and incorporates a multi-stage cutting and stirring device. It is equipped with three layers of spiral blades, with the blade spacing in each layer being 1 / 5 of the effective height of the macro / microstructure modification reactor. The spiral blades are distributed stainless steel blades. The first and third layers consist of three blades spaced at 120° intervals with a 45° twist. The second layer consists of six blades spaced at 60° intervals with a 30° twist. The blade length is 1 / 3 of the effective inner diameter of the macro / microstructure modification reactor. The multi-stage cutting and stirring device 10 is used to cut and stir the fruit and vegetable waste for 5 minutes at a speed of 150 rpm, initially breaking down the waste and resulting in uneven, blocky pieces. Subsequently, the vibrating fluidization device 11 was turned on, and the fruit and vegetable waste was vibrated and fluidized at a vibration frequency of 500 r / min. At the same time, the rotation speed of the multi-stage cutting and stirring device 10 was changed to 450 rpm. Under high-speed cutting and stirring conditions, the fruit and vegetable waste was cut and stirred by the multi-stage cutting and stirring device 10 for 20 minutes. Through the combined action of vibration fluidization and multi-stage mechanical cutting and stirring, the fruit and vegetable waste was transformed into a uniform small particle shape, thereby modifying the macroscopic structure of the fruit and vegetable waste and realizing multi-stage mechanical granulation of the fruit and vegetable waste to obtain fruit and vegetable waste with a uniform small particle shape. The average particle size of the obtained fruit and vegetable waste particles was 18 mm.Alkaline wood ash with a pH of 11 and a soluble potassium content of 9% was added to the macro / micro structure modification reactor 9 through a solid metering feeding device 13 and an alkaline wood ash feeding port 14. The dosage of alkaline wood ash was 1.25 g / g. TS fruit and vegetable waste is stirred for 3 minutes at a low speed of 150 rpm using a multi-stage cutting agitator 10. Simultaneously, a vibrating fluidization device is used to vibrate and fluidize the fruit and vegetable waste and alkaline wood ash at a vibration frequency of 200 rpm, improving the mixing uniformity of the fruit and vegetable waste particles and alkaline wood ash. The alkaline wood ash promotes alkaline decomposition of the fruit and vegetable waste particles, modifying their microstructure, resulting in a mixture D of fruit and vegetable waste particles and alkaline wood ash. The pH value of mixture D is measured to be 10.0 using a pH meter 40. The mixture is then discharged from the second discharge port 15 and fed into the hydrothermal reactor 17 from the mixture feeding port 20 using a second screw feeder 16. The hydrothermal reaction is carried out at a temperature of 220℃ for 60 minutes using a heating and temperature control device 19, while the mixture D is stirred at a speed of 80 rpm using a second stirring device 18. During this process, the hydrothermal reactor is strictly sealed, and the pressure is monitored using 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 explosion-proof plate 23 are opened to release the pressure, resulting in the hydrothermal carbonization mixture E, which is discharged from the third outlet 22. The hydrothermal carbonization mixture E is then fed into the suspended percolation tank 25 using the feed pump 24. The suspended percolation tank is long. The suspended infiltration tank is 6m long and 2m wide. An upper filter cloth support 26 is installed on the upper layer. A suspended filter cloth 27 of the same size as the suspended filter tank is provided. The mesh size of the suspended filter cloth is 250 mesh. The hydrothermal carbonization mixture is evenly spread on the surface of the suspended filter cloth 27 using a metal cloth plate 28 and a mechanical transmission machine 29. After standing for 10 hours, gravity infiltration and dewatering are achieved. The solids retained on the surface of the suspended filter cloth are the hydrothermal carbon particles for fruits and vegetables. The hydrothermal liquid is filtered from the suspended filter cloth into the suspended infiltration tank. The moisture content of the hydrothermal char granules was measured to be 35% using a moisture meter 37. The hydrothermal char granules were collected from the surface of the suspended filter cloth and placed into the washing tank 32. Clean water was injected into the washing tank from the washing storage tank 36. The tank was stirred at 300 rpm for 1 hour using a third stirring device 33. The washing process was repeated 3 times to complete the washing of the hydrothermal char granules. The washing water was then discharged from the washing water outlet 35 at the bottom of the washing tank. At the same time, the hydrothermal char granules were trapped by a filter screen 34 installed at the outlet. The filter screen had a pore size of 0.08 mm. The washed hydrothermal char granules were collected and laid flat outdoors to air dry under sunlight for 24 hours to obtain dried fruit and vegetable hydrothermal char granules. The property indicators of the fruit and vegetable hydrothermal char granules were tested using an elemental analyzer 38 and a capacitance tester 39. The results are as follows. Figure 4As shown: the hydrothermal char yield was 39.11%, higher than the 28.68% of the control group treated by traditional hydrothermal carbonization; the carbon content of the hydrothermal char product was 61.66%, close to the 63.78% of the control group; the phosphorus content of the hydrothermal char product was 0.18%, higher than the 0.164% of the control group; the potassium content of the hydrothermal char product was 3.229%, higher than the 0.0185% of the control group, mainly due to the introduction of a large amount of potassium into the fruit and vegetable hydrothermal char by alkaline wood ash; the specific capacitance of the hydrothermal char product was 6.73 F / g, higher than the 2.98 F / g of the control group, indicating better electrochemical properties. Other indicators of the hydrothermal char product of this application were stronger than the control group, the carbon content was close to the control group, and the overall quality was superior to the control group; the properties of the hydrothermal char particles met the requirements, and the collected and dried fruit and vegetable hydrothermal char was used as a soil conditioner. Simultaneously, hydrothermal liquid was collected from the hydrothermal liquid collection hopper 30 at the bottom of the suspended infiltration tank 25 and discharged into the sewage treatment system through the hydrothermal liquid discharge pipe and valve 31 as a supplementary carbon source.

[0163]

[0164] As can be seen from the table above, compared with traditional hydrothermal carbonization technology, the yield of hydrothermal carbon can be increased by 10-40% after the organic waste of this application is treated with alkaline wood ash coupled with multi-stage mechanical granulation; the carbon content can be increased by up to 47%, the phosphorus content by up to 9.8%, and the potassium content by up to 17,000 times, effectively enriching the nutrients of the hydrothermal carbon particles; in addition, the specific capacitance of the hydrothermal carbon particles can be increased by 50-125%, resulting in superior electrochemical properties.

[0165] The principle of this application is as follows:

[0166] This application utilizes a vibrating fluidization device to vibrate and fluidize organic waste, and a three-layer spiral blade impeller to perform multi-stage cutting and stirring of the organic waste. The combined action of these two processes achieves multi-stage mechanical granulation of the organic waste, disrupting and modifying its macroscopic structure to transform it into uniform small particles. Subsequently, alkaline wood ash is used to promote the alkaline decomposition of biomass molecules in the uniform small particles, disrupting and modifying the microscopic structure of the organic waste and improving its hydrothermal activity. Under the coupled effect of the multi-stage mechanical granulation and alkaline wood ash, the macroscopic and microscopic structures of the organic waste are simultaneously modified and transformed, improving hydrothermal carbonization efficiency and hydrothermal char product recovery rate, and inhibiting the generation of by-products. This solves the bottleneck constraints of the macroscopic physical structure of organic waste limiting hydrothermal mass transfer efficiency, and the microscopic chemical structure of biomass such as cellulose limiting hydrolysis efficiency and hydrothermal activity. Simultaneously, alkaline wood ash contains abundant potassium, which can supplement the organic waste with potassium fertilizer, increasing the potassium content of the hydrothermal char product, enriching and improving the nutrient composition distribution of the hydrothermal char product, and enhancing the quality of the hydrothermal char product as a soil conditioner and its soil remediation effect.

[0167] After undergoing the aforementioned alkaline wood ash coupled multi-stage mechanical granulation treatment, organic waste is subjected to hydrothermal carbonization under specific hydrothermal temperature and saturated vapor pressure conditions. The treated mixture is then dehydrated via percolation on a suspended filter cloth, achieving solid-liquid separation. The resulting solid-phase hydrothermal char is washed, dried, and recycled for use as a soil conditioner. The hydrothermal liquid is discharged for anaerobic digestion to produce methanogens or discharged into a wastewater treatment system as a supplementary carbon source. This application utilizes specific equipment and matching technical parameters to achieve organic waste disposal, and proposes specific technical parameters for three types of organic waste: dewatered sludge, fruit and vegetable waste, and landscaping waste, allowing for flexible matching to different organic waste categories. Furthermore, this application proposes evaluation indicators for hydrothermal char products and incorporates a built-in detector in the device to limit the range of hydrothermal char yield, carbon-phosphorus-potassium element ratio, and hydrothermal char specific capacitance. If the indicator requirements are not met, secondary treatment is required to ensure the stability of the technical effect and guarantee the quality of the potassium-rich, ultra-high-quality hydrothermal char product.

[0168] This application aims to economically and efficiently convert organic waste into potassium-rich, high-quality hydrothermal char products. These products increase soil porosity, alter soil particle composition, enhance soil water retention, replenish carbon, nitrogen, phosphorus, and potassium elements to improve soil fertility, adsorb and retain nutrients in the soil to reduce nutrient loss, regulate soil pH, promote soil microbial activity and decompose organic matter, and improve soil enzyme activity, thereby achieving soil improvement and remediation.

[0169] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

[0170] 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 the specific embodiments, and the scope of this application is defined by the appended claims.

Claims

1. A method for enhancing the hydrothermal carbonization of organic waste through coupled granulation of plant ash, characterized in that, Includes the following steps: S1: Dehydrate or dilute the organic waste with water to adjust the moisture content of the organic waste to 80-90% to obtain organic waste A with adjusted moisture content; S2: Organic waste A is put into the macro / micro structure modification reactor (9), and the organic waste A is cut and stirred at low speed using a multi-stage cutting stirrer (10) to initially break the structure of organic waste A and obtain uneven blocky organic waste B. S3: The organic waste B is subjected to high-frequency vibration fluidization using a vibration fluidization device (11), and the organic waste B is subjected to high-speed cutting and stirring using a multi-stage cutting and stirring device (10). Through the combined action of high-frequency vibration fluidization and high-speed 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 and obtaining organic waste C with a uniform small particle form. S4: Add alkaline wood ash to the macro / micro structure modification reactor (9). The amount of alkaline wood ash added is 0.25~1.25g / g TS of organic waste C. Perform low-speed cutting and stirring. At the same time, use a vibrating fluidization device (11) to perform low-frequency vibration fluidization on organic waste C and alkaline wood ash. Use alkaline wood ash to promote alkaline decomposition of organic waste C and modify the microstructure of organic waste C to obtain a mixture D of organic waste C and alkaline wood ash. The pH of mixture D is 8.0~10.

5. S5: Add mixture D into hydrothermal reactor (17) and carry out hydrothermal reaction at 160~230℃ for 25~100min. At the same time, stir mixture D at a speed of 20~100rpm. During this process, the hydrothermal reactor (17) is strictly sealed to maintain a saturated vapor pressure environment, and the hydrothermal carbonization reaction is completed to obtain hydrothermal carbonized mixed product E. S6: Add the hydrothermal carbonization mixture 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: Collect hydrothermal carbon particles and put them into the cleaning tank (32) to complete the cleaning of hydrothermal carbon particles. Then discharge the cleaning water from the cleaning water outlet (35) at the bottom of the cleaning tank (32) and use the filter screen (34) set at the cleaning water outlet (35) to trap the hydrothermal carbon particles. S9: Collect the cleaned hydrothermal carbon particles, spread them out outdoors, and air dry them under sunlight for 6-24 hours to obtain dried hydrothermal carbon particles. Test the carbon, nitrogen, phosphorus, and potassium ratios and specific capacitance of the hydrothermal carbon particles. If they pass the test, collect them for use as a soil conditioner. S10: Collect hydrothermal liquid 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 enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 1, characterized in that: The organic waste in S1 is one or more of the following: dewatered sludge, fruit and vegetable waste, and garden greening waste; When the moisture content of organic waste is <80%, add clean water to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is >90%, dehydrate the organic waste to adjust the moisture content of organic waste to 80-90%; when the moisture content of organic waste is 80-90%, step S1 is not required. In S2, a multi-stage cutting and stirring device (10) is used to cut and stir organic waste A at low speed for 1 to 5 minutes, with the rotation speed set to 100 to 250 rpm.

3. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 2, characterized in that: In S3, the organic waste B is subjected to high-frequency vibration fluidization using a vibration fluidization device (11) with a vibration frequency of 200~700r / min, and the organic waste B is subjected to high-speed cutting and stirring using a multi-stage cutting and stirring device (10) for 5~20min with a rotation speed of 250~700rpm. When the organic waste is dewatered sludge, the speed of the multi-stage cutting mixer (10) is set to 250~350 rpm, and the organic waste B is cut and stirred at high speed for 5~15 min, and the average particle size of the organic waste C is 3~20 mm. When the organic waste is fruit and vegetable waste, the speed of the multi-stage cutting mixer (10) is set to 350~500 rpm, and the organic waste B is cut and mixed at high speed for 5~20 min, and the average particle size of the organic waste C is 1~15 mm. When the organic waste is garden greening waste, the speed of the multi-stage cutting mixer (10) is set to 500~700 rpm, and the organic waste B is cut and stirred at high speed for 10~20 min, and the average particle size of the organic waste C is 1~15 mm.

4. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 2, characterized in that: The alkaline wood ash used in S4 has a pH of 10.5~12 and a soluble K element content of ≥7%. The alkaline wood ash is added to the macro / micro structure modification reactor (9) and stirred at a speed of 50~150 rpm for 1~3 min. At the same time, the organic waste C and alkaline wood ash are subjected to low-frequency vibration fluidization using a vibration fluidization device (11) with a vibration frequency of 100~450 r / min.

5. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 4, characterized in that: In step S4, alkaline wood ash is added and mixed with organic waste C to obtain mixture D. By adjusting the amount of alkaline wood ash added, the pH of mixture D is ensured to be 8.0~10.

5. When the organic waste is dewatered sludge, the pH of mixture D is 9.0~10.5; When the organic waste is fruit and vegetable waste, the pH of mixture D is 8.5~10.0; When the organic waste is landscaping waste, the pH of mixture D is 8.0~9.

5.

6. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 2, characterized in that: In step S5, when the organic waste is dewatered sludge, the hydrothermal temperature is 160~200℃ and the hydrothermal time is 25~50min; when the organic waste is fruit and vegetable waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min; when the organic waste is garden and landscaping waste, the hydrothermal temperature is 200~230℃ and the hydrothermal time is 40~100min. In step S6, the hydrothermal carbonization mixture E is added into the suspended percolation tank (25). A suspended filter cloth (27) is set 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) using a cloth plate (28). After standing for 1 to 12 hours, gravity percolation dewatering is achieved. The solids retained on the surface of the suspended filter cloth (27) are hydrothermal carbon particles. The hydrothermal liquid is percolated from the suspended filter cloth (27) into the suspended percolation tank (25).

7. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 2, characterized in that: In step S8, hydrothermal carbon particles are added to a washing tank (32) and stirred at a speed of 100~300 rpm for 0.5~2 hours, and the washing is repeated 1~5 times. When the organic waste is dewatered sludge, the hydrothermal carbon granules are washed 3 to 5 times. When the organic waste is fruit and vegetable waste, the hydrothermal charcoal granules are washed 2-4 times. When the organic waste is landscaping waste, the hydrothermal carbon granules should be washed 1-3 times.

8. The method for enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash according to claim 2, characterized in that: The hydrothermal carbon particles dried in S9 were tested, and the hydrothermal carbon yield of dewatered sludge was ≥50%, the hydrothermal carbon yield of fruit and vegetable waste was ≥30%, and the hydrothermal carbon yield of garden greening waste was ≥60%. The hydrothermal carbon content of dewatered sludge is ≥30%, the hydrothermal carbon content of fruit and vegetable waste is ≥55%, and the hydrothermal carbon content of landscaping waste is ≥60%. The hydrothermal carbon and phosphorus content of dewatered sludge is ≥3%, that of fruit and vegetable waste is ≥0.15%, and that of landscaping waste is ≥0.2%. The hydrothermal carbon and potassium content of dewatered sludge is ≥2%, that of fruit and vegetable waste is ≥2.5%, and that of landscaping waste is ≥1%. The hydrothermal carbon specific capacitance of dewatered sludge is ≥1.8F / g, that of fruit and vegetable waste is ≥6.5F / g, and that of landscaping waste is ≥5F / g.

9. A device for enhanced hydrothermal carbonization of organic waste through plant ash coupling granulation, characterized in that: The method for implementing the enhanced hydrothermal carbonization of organic waste by coupled granulation of plant ash as described in any one of claims 1 to 8 includes a moisture content adjustment module, a macro / micro structure modification module, a hydrothermal carbonization reaction module, a suspended percolation module, a hydrothermal carbon particle cleaning module, a detection module, and a control component. The moisture content adjustment module, macro / micro structure modification module, hydrothermal carbonization reaction module, suspended percolation module, hydrothermal carbon particle cleaning module, and detection module are respectively electrically connected to the control component. The moisture content adjustment module includes a moisture content adjustment tank (1) and a dewatering machine (7). The moisture content adjustment tank (1) is provided with a first organic waste inlet (2), a water inlet (3), a first stirring device (5) and a first discharge outlet (6). The water inlet (3) is connected to a water tank (4). The dewatering machine (7) is also provided with a first discharge outlet (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 equipped with a multi-stage cutting agitator (10) and a vibrating fluidization device (11). The macro / micro structure modification reactor (9) is also provided with a second organic waste inlet (12), an alkaline wood ash inlet (14), and a second discharge outlet (15). The vibrating fluidization device (11) is located at the bottom of the macro / micro structure modification reactor (9), and the solid metering feeding device (13) is located at the top of the alkaline wood ash inlet (14). The bottom of the first screw feeder (8) is connected to the first discharge outlet (6), and the top of the first screw feeder (8) is connected to the second organic waste inlet (12). The hydrothermal carbonization reaction module includes a second screw feeder (16) and a hydrothermal reactor (17). The hydrothermal reactor (17) is equipped with a second stirring device (18) and a heating and temperature control device (19). The hydrothermal reactor (17) is also equipped with a mixture feeding port (20), a pressure monitoring device (21), a third discharge port (22), a pressure relief valve, and an explosion-proof plate (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 percolation module includes a feeding pump (24) and a suspended percolation tank (25). An upper filter cloth support (26) is set inside the suspended percolation tank (25). A suspended filter cloth (27) is placed on the upper filter cloth support (26). A cloth plate (28) is provided on the surface of the suspended filter cloth (27). The cloth plate (28) is connected to a mechanical transmission machine (29). A hydrothermal liquid collection hopper (30) and a hydrothermal liquid discharge pipe and valve (31) are provided at the bottom of the suspended percolation tank (25). One end of the feeding 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 pool (32). The cleaning pool (32) has a built-in third stirring device (33). The bottom of the cleaning pool (32) is provided with a filter screen (34) and a cleaning water outlet (35). The cleaning water storage tank (36) is connected to the cleaning pool (32). The detection module includes a moisture content meter (37), an elemental analyzer (38), a capacitance tester (39), and a pH meter (40). The moisture content meter (37) is used to detect the moisture content of organic waste A at the first discharge port (6) and hydrothermal carbon particles on the suspended filter cloth (27). The pH meter (40) is used to detect the pH of mixture D at the second outlet (15); The moisture content meter (37), elemental analyzer (38), capacitance meter (39) and pH meter (40) are also used to detect the properties of the hydrothermal carbon particles at the filter screen (34).

10. The apparatus for enhanced hydrothermal carbonization of organic waste via plant ash coupling granulation according to claim 9, characterized in that: The macro / micro structure modification reactor (9) is a cylindrical barrel reactor with a diameter-to-height ratio of 1:3 to 5:

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

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