Kitchen waste gasification and supercritical hydro-thermal synthesis copper powder preparation treatment system and method

Abstract

The invention relates to the technical field of waste resource utilization, and discloses a kitchen waste gasification and supercritical hydro-thermal synthesis copper powder preparation treatment system and method. The system comprises a waterway output pipeline, a kitchen waste output pipeline, a supercritical water gasification reactor unit, a supercritical hydrothermal synthesis reactor, a copper solution output unit, a liquid oxygen output pipeline, an oxidation reactor and a liquid-solid separator. Through cooperative work of the water path output pipeline, the kitchen waste output pipeline, the liquid oxygen output pipeline, the supercritical water gasification reactor unit, the copper solution output unit, the oxidation reactor, the liquid-solid separator and other modules, the preparation efficiency of the superfine copper powder can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of waste resource utilization, and in particular to a system and method for preparing kitchen waste gasification and supercritical hydrothermal synthesis copper powder. Background Art

[0002] With the continuous development of the economy and the continuous improvement of living standards, the amount of food waste generated each year has exceeded 1.3 billion tons. These wastes are rich in organic components such as carbohydrates, proteins and fats. However, these organic substances are not only prone to produce odor and breed bacteria during the decomposition process, but also aggravate environmental pollution problems. Although traditional food waste treatment methods, such as landfill and incineration, have alleviated the pressure of waste disposal to a certain extent, they have brought new problems. The landfill method will occupy a large amount of land resources, and the leachate of garbage may pollute the soil and water sources; while incineration can reduce the volume of garbage, it will produce a large amount of harmful gases, such as carbon dioxide, which not only pollutes the air, but also aggravates global warming. Therefore, traditional treatment methods are facing increasing environmental and social pressures, and it is urgent to develop more environmentally friendly and sustainable food waste treatment technologies.

[0003] At the same time, due to its unique physical and chemical properties, ultrafine copper powder has shown broad application prospects in many fields such as new energy, electronic industry, and environmental protection, and its demand is growing. However, the preparation technology of ultrafine copper powder still faces many challenges. At present, the preparation methods of ultrafine copper powder can be mainly divided into gas phase method, solid phase method and liquid phase method. Although the gas phase method can produce high-quality ultrafine copper powder, it has high requirements on equipment, harsh reaction conditions and high production cost; the solid phase method has simple equipment, convenient operation and relatively low cost, but there are limitations in the particle size of ultrafine copper powder, and it is easy to introduce impurities, affecting the purity and performance of the product; although the liquid phase method often uses certain reducing agents to complete the reaction, these reducing agents are mostly expensive chemical reagents, which increases the production cost.

[0004] Therefore, there is an urgent need to find more efficient, environmentally friendly and sustainable solutions in terms of food waste treatment technology and ultrafine copper powder preparation technology. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a system and method for preparing copper powder by gasification of food waste and supercritical hydrothermal synthesis, so as to solve the technical problem of how to prepare ultrafine copper powder by effectively utilizing food waste in the prior art.

[0006] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder, comprising a water output pipeline, a kitchen waste output pipeline, a supercritical water gasification reactor unit, a supercritical hydrothermal synthesis reactor, a copper solution output unit, a liquid oxygen output pipeline, an oxidation reactor, and a liquid-solid separator; The output ends of the water output pipeline and the kitchen waste output pipeline are respectively connected to the input end of the supercritical water gasification reactor unit; the output end of the supercritical water gasification reactor unit is connected to the input end of the supercritical hydrothermal synthesis reactor; The input end of the copper solution output unit is used to input the copper precursor solution and the alkaline solution, and the output end is connected to the input end of the supercritical hydrothermal synthesis reactor; the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor is connected to the input end of the liquid-solid separator; The output end of the liquid oxygen output pipeline and the gasification output end of the supercritical hydrothermal synthesis reactor are respectively connected to the input end of the oxidation reactor. The output end of the oxidation reactor passes through the water output pipeline, the food waste output pipeline and the liquid oxygen output pipeline in sequence, and is used to preheat the water output pipeline, the food waste output pipeline and the liquid oxygen output pipeline.

[0007] Preferably, the supercritical water gasification reactor unit comprises a supercritical water gasification reactor; The input end of the supercritical water gasification reactor is respectively connected to the output ends of the water output pipeline and the food waste output pipeline; the output end of the supercritical water gasification reactor is connected to the input end of the supercritical hydrothermal synthesis reactor; wherein the outer wall of the supercritical water gasification reactor is provided with a heating device.

[0008] Furthermore, a slag discharge port is provided at the bottom of the supercritical water gasification reactor, and an output end of the slag discharge port is connected to a lock hopper; wherein a first cooler is provided between the supercritical water gasification reactor and the lock hopper.

[0009] Furthermore, a water injection pipeline and a slag discharge pipeline are provided on the lock hopper, wherein the water injection pipeline is provided with a water injection ball valve, and the slag discharge pipeline is provided with a slag discharge needle valve.

[0010] Preferably, the copper solution output unit includes a copper precursor solution pipeline and an alkaline solution pipeline; The input end of the copper precursor solution pipeline is provided with a copper precursor solution pump for inputting the copper precursor solution; the input end of the alkaline solution pipeline is provided with an alkaline solution pump for inputting the alkaline solution; The output ends of the copper precursor solution pipeline and the alkaline solution pipeline are respectively connected to the input end of the supercritical hydrothermal synthesis reactor.

[0011] Preferably, a second cooler is provided between the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor and the input end of the liquid-solid separator.

[0012] Preferably, a water pump and a first heat exchanger are sequentially provided on the water output pipeline; a slurry pump and a third heat exchanger are sequentially provided on the food waste output pipeline; and a liquid oxygen pump, an air preheater and a second heat exchanger are sequentially provided on the liquid oxygen output pipeline.

[0013] Furthermore, the oxidation reactor is provided with a first input end and a second input end; wherein, the output end of the liquid oxygen output pipeline is connected to the first input end, and the gasification output end of the supercritical hydrothermal synthesis reactor is connected to the second input end; the output end of the oxidation reactor is connected to a gas-liquid separator after passing through the first heat exchanger, the second heat exchanger and the third heat exchanger in sequence.

[0014] Furthermore, a third cooler is provided between the third heat exchanger and the gas-liquid separator.

[0015] In a second aspect, the present invention further provides a method for preparing copper powder by gasification and supercritical hydrothermal synthesis of kitchen waste, based on the above-mentioned system for preparing copper powder by gasification and supercritical hydrothermal synthesis of kitchen waste, comprising the following steps: The kitchen waste slurry and water are respectively preheated through the kitchen waste output pipe and the water output pipe, and then input into the supercritical water gasification reactor unit; The gasification product in the supercritical water gasification reactor unit flows into the supercritical water thermal synthesis reactor as a reducing agent and heat source after ash separation; An alkaline solution is input as a particle modifier and a copper precursor solution into a supercritical hydrothermal synthesis reactor through a copper solution output unit, and reacted in combination with a reducing agent in the supercritical hydrothermal synthesis reactor, wherein the liquid of the supercritical hydrothermal synthesis reactor flows into a liquid-solid separator and is separated by the liquid-solid separator to obtain ultrafine copper powder; the remaining product in the supercritical hydrothermal synthesis reactor enters an oxidation reactor, liquid oxygen is input into the oxidation reactor through a liquid oxygen output pipeline, and undergoes an oxidation reaction with the remaining product to release heat, and the heat is sequentially preheated to a water output pipeline, a food waste output pipeline and a liquid oxygen output pipeline.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a kitchen waste gasification and supercritical hydrothermal synthesis copper powder preparation and processing system. By using kitchen waste as raw material input, the effective utilization of waste is achieved, and the environmental pollution caused by garbage landfill and incineration is reduced. The kitchen waste can be converted into valuable energy or intermediate products after gasification treatment in a supercritical water gasification reactor, thereby improving the recycling rate of resources. Copper powder is prepared by a supercritical hydrothermal synthesis reactor, and the hydrogen-rich gas generated by gasification can directly replace the reducing agent to reduce the ultrafine copper powder. The water output pipeline, the kitchen waste output pipeline and the liquid oxygen output pipeline are preheated in sequence by an oxidation reactor. The present invention integrates the two processes of kitchen waste gasification and supercritical hydrothermal synthesis of copper powder. The water output pipeline, the kitchen waste output pipeline, the liquid oxygen output pipeline, the supercritical water gasification reactor unit, the copper solution output unit, the oxidation reactor and the liquid-solid separator and other modules work together to effectively improve the efficiency of preparing ultrafine copper powder.

[0017] Furthermore, the supercritical water gasification reactor can significantly improve the gasification efficiency of food waste by utilizing the properties of supercritical water. Under the supercritical state, the organic matter in the food waste can be more effectively decomposed and converted to generate gas products. The heating device performs precise temperature control on the supercritical water gasification reactor. By precisely controlling the temperature, it can be ensured that the water in the reactor is always in a supercritical state, thereby optimizing the gasification reaction conditions.

[0018] Furthermore, the setting of the slag discharge port enables the solid residue in the reactor to be discharged continuously and stably, avoiding the accumulation of residue in the reactor, thereby ensuring the continuous and efficient progress of the gasification reaction. The setting of the first cooler cools the high-temperature residue discharged from the reactor, thereby reducing the temperature of the residue, making it easier to handle and store, and also reducing the safety risks that may be caused by high-temperature residue.

[0019] Furthermore, the water injection ball valve can accurately control the amount of water injected into the lock hopper to ensure the accuracy and stability of the water volume. The slag discharge needle valve can accurately control the opening and closing of the slag discharge pipeline to ensure that the residue in the lock hopper can be discharged efficiently and stably, avoiding the accumulation and blockage of the residue.

[0020] Furthermore, the copper precursor solution pump and the alkaline solution pump can accurately control the input amount of the copper precursor solution and the alkaline solution, ensuring that the two solutions enter the supercritical hydrothermal synthesis reactor at an appropriate ratio and flow rate, thereby optimizing the conditions of the synthesis reaction. By accurately controlling the input of the solution, it is possible to ensure that the reactant concentration and pH value in the supercritical hydrothermal synthesis reactor are in an optimal state, thereby improving the efficiency of the synthesis reaction and the purity of the product.

[0021] Furthermore, the second cooler cools the liquid-solid mixture output from the supercritical hydrothermal synthesis reactor, which helps to reduce the temperature of the product to a range suitable for processing by the liquid-solid separator, thereby ensuring the smooth progress of the separation process. Pre-cooling by the second cooler can effectively protect the liquid-solid separator, extend its service life, and reduce maintenance costs.

[0022] Furthermore, the water pump improves the water flow power in the waterway, ensuring that water can flow to the supercritical water gasification reactor stably and efficiently, which helps to ensure that the water in the reactor is always in a supercritical state and provides the necessary water environment and pressure conditions for the gasification reaction. The first heat exchanger accurately adjusts the water temperature entering the supercritical water gasification reactor, thereby optimizing the gasification reaction conditions and improving the reaction efficiency and product quality. The setting of the slurry pump significantly improves the transportation efficiency of food waste, and the third heat exchanger adjusts the temperature of the garbage slurry entering the reactor. The liquid oxygen pump, air preheater and second heat exchanger arranged on the liquid oxygen output pipeline can accurately adjust the temperature of the liquid oxygen, ensuring that the liquid oxygen reaches the optimal reaction temperature before entering the oxidation reactor, thereby improving the efficiency and stability of the oxidation reaction.

[0023] Furthermore, the output end of the oxidation reactor is connected to the gas-liquid separator through the first heat exchanger, the second heat exchanger and the third heat exchanger in sequence, so that a large amount of heat energy released during the oxidation reaction can be recovered and utilized in multiple stages. The setting of the gas-liquid separator can efficiently separate the gas-liquid mixture output by the oxidation reactor, ensure the purity of the gas and liquid in the subsequent processing steps, and improve the processing efficiency and product quality of the entire system.

[0024] Furthermore, a third cooler is provided between the third heat exchanger and the gas-liquid separator, and the third cooler adjusts the temperature of the gas-liquid mixture output from the third heat exchanger. By precisely controlling the cooling intensity, it is possible to ensure that the temperature of the gas-liquid mixture is reduced to a range suitable for processing by the gas-liquid separator, thereby improving separation efficiency and separation quality.

[0025] The present invention also provides a method for preparing copper powder by gasification of kitchen waste and supercritical hydrothermal synthesis, which realizes high-value utilization of kitchen waste by converting the kitchen waste into gasification products and using them as reducing agents and heat sources in the subsequent copper powder preparation process. This not only reduces the environmental pollution caused by landfill and incineration, but also improves the utilization efficiency of resources. In the supercritical hydrothermal synthesis reactor, the gasification products fully react with the alkaline solution and the copper precursor solution to form copper particles. Due to the special properties of supercritical water, the mass transfer and heat transfer efficiency during the reaction are extremely high, which is conducive to the uniform growth and particle size control of copper particles. In addition, the use of a liquid-solid separator can further purify the copper powder and improve its quality and purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of a system for preparing and processing kitchen waste gasification and supercritical hydrothermal synthesis of copper powder in an embodiment of the present invention; In the figure: 1. water pump; 2. liquid oxygen pump; 3. slurry pump; 4. air preheater; 5. first heat exchanger; 6. second heat exchanger; 7. third heat exchanger; 8. first cooler; 9. gas-liquid separator; 10. supercritical water gasification reactor; 11. heating device; 12. supercritical hydrothermal synthesis reactor; 13. second cooler; 14. oxidation reactor; 15. copper precursor solution pump; 16. alkaline solution pump; 17. liquid-solid separator; 18. third cooler; 19. lock hopper. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings: The purpose of the present invention is to provide a system and method for preparing copper powder by gasification of kitchen waste and supercritical hydrothermal synthesis, so as to solve the technical problem of how to prepare ultrafine copper powder by effectively utilizing kitchen waste in the prior art.

[0029] Example 1 See also Figure 1In one embodiment of the present invention, a system for preparing copper powder by gasification of kitchen waste and supercritical hydrothermal synthesis is provided, comprising a water output pipeline, a kitchen waste output pipeline, a supercritical water gasification reactor unit, a supercritical hydrothermal synthesis reactor 12, a copper solution output unit, a liquid oxygen output pipeline, an oxidation reactor 14 and a liquid-solid separator 17; the output ends of the water output pipeline and the kitchen waste output pipeline are respectively connected to the input end of the supercritical water gasification reactor unit; the output end of the supercritical water gasification reactor unit is connected to the input end of the supercritical hydrothermal synthesis reactor 12; the copper solution output unit is connected to ... The input end of the element is used to input a copper precursor solution and an alkaline solution, and the output end is connected to the input end of a supercritical hydrothermal synthesis reactor 12; the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor 12 is connected to the input end of a liquid-solid separator 17; the output end of the liquid oxygen output pipeline and the gasification output end of the supercritical hydrothermal synthesis reactor 12 are respectively connected to the input end of an oxidation reactor 14, and the output end of the oxidation reactor 14 passes through a water output pipeline, a food waste output pipeline and a liquid oxygen output pipeline in sequence, and is used to preheat the water output pipeline, the food waste output pipeline and the liquid oxygen output pipeline.

[0030] Specifically, the supercritical water gasification reactor unit includes a supercritical water gasification reactor 10; the input end of the supercritical water gasification reactor 10 is respectively connected to the output ends of the water output pipeline and the food waste output pipeline; the output end of the supercritical water gasification reactor 10 is connected to the input end of the supercritical hydrothermal synthesis reactor 12; wherein the outer wall of the supercritical water gasification reactor 10 is provided with a heating device 11.

[0031] A slag discharge port is also provided at the bottom of the supercritical water gasification reactor 10 , and an output end of the slag discharge port is connected to a lock hopper 19 ; a first cooler 8 is provided between the supercritical water gasification reactor 10 and the lock hopper 19 .

[0032] Among them, the lock hopper 19 is provided with a water injection pipeline and a slag discharge pipeline, wherein the water injection pipeline is provided with a water injection ball valve, and the slag discharge pipeline is provided with a slag discharge needle valve.

[0033] The structural principle in this embodiment is as follows: The kitchen waste slurry and water are preheated through the kitchen waste output pipeline and the water output pipeline respectively, and then input into the supercritical water gasification reactor 10. In the supercritical water gasification reactor 10, the kitchen waste slurry and water reach a supercritical state under high temperature and high pressure conditions, and a gasification reaction occurs. The gasification products mainly include gas and a small amount of ash. The outer wall of the supercritical water gasification reactor 10 is provided with a heating device 11, which is used to provide the heat required for the reaction and maintain the temperature and pressure in the reactor in a supercritical state. The ash produced during the gasification reaction is discharged through the slag discharge port at the bottom of the reactor and enters the first cooler 8 for cooling. The cooled ash falls into the lock hopper 19 for temporary storage. The lock hopper 19 is provided with a water injection pipeline and a slag discharge pipeline. The water injection pipeline is used to inject water into the lock hopper 19 to adjust the humidity and fluidity of the ash; the slag discharge pipeline is used to discharge the ash from the lock hopper 19. The water injection pipeline is provided with a water injection ball valve for controlling the water injection amount; the slag discharge pipeline is provided with a slag discharge needle valve for controlling the slag discharge amount. The gasification product flows out from the output end of the supercritical water gasification reactor 10 and is input into the supercritical water thermal synthesis reactor 12 as a reducing agent and heat source for the subsequent copper powder preparation process.

[0034] Specifically, the copper solution output unit includes a copper precursor solution pipeline and an alkaline solution pipeline; a copper precursor solution pump 15 is provided at the input end of the copper precursor solution pipeline for inputting the copper precursor solution; an alkaline solution pump 16 is provided at the input end of the alkaline solution pipeline for inputting the alkaline solution; the output ends of the copper precursor solution pipeline and the alkaline solution pipeline are respectively connected to the input end of the supercritical hydrothermal synthesis reactor 12.

[0035] The structural principle in this embodiment is as follows: A copper precursor solution pump 15 is provided at the input end of the copper precursor solution pipeline to provide sufficient pressure to ensure that the copper precursor solution can be stably and continuously input into the pipeline. An alkaline solution pump 16 is provided at the input end of the alkaline solution pipeline to also provide stable pressure to ensure that the alkaline solution can be smoothly input into the pipeline. In the process of preparing copper powder by gasification of kitchen waste and supercritical hydrothermal synthesis, when copper powder needs to be prepared, the copper precursor solution pump 15 and the alkaline solution pump 16 are first started. The copper precursor solution pump 15 extracts the copper precursor solution from the storage container and transports it to the input end of the supercritical hydrothermal synthesis reactor 12 through the copper precursor solution pipeline. At the same time, the alkaline solution pump 16 also extracts the alkaline solution from the storage container and transports it to the input end of the supercritical hydrothermal synthesis reactor 12 through the alkaline solution pipeline. In the supercritical hydrothermal synthesis reactor 12, the copper precursor solution and the alkaline solution undergo a chemical reaction in a supercritical water environment. As a particle modifier, the alkaline solution can adjust the pH value of the reaction system, promote the uniform growth of copper particles and control the particle size. At the same time, the properties of supercritical water are conducive to the full mixing and mass transfer of reactants, thereby accelerating the chemical reaction.

[0036] Specifically, a second cooler 13 is provided between the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor 12 and the input end of the liquid-solid separator 17 .

[0037] The structural principle in this embodiment is as follows: Before entering the liquid-solid separator 17, the liquid-solid mixture first passes through the second cooler 13, and the second cooler 13 cools the liquid-solid mixture through a certain cooling medium to reduce its temperature to a range suitable for liquid-solid separation. During the cooling process, it is necessary to ensure that the temperature and pressure of the liquefied product are within a safe and controllable range to avoid unnecessary chemical reactions or safety hazards.

[0038] Specifically, a water pump 1 and a first heat exchanger 5 are sequentially provided on the water output pipeline; a slurry pump 3 and a third heat exchanger 7 are sequentially provided on the food waste output pipeline; and a liquid oxygen pump 2, an air preheater 4 and a second heat exchanger 6 are sequentially provided on the liquid oxygen output pipeline.

[0039] The oxidation reactor 14 is provided with a first input end and a second input end; the output end of the liquid oxygen output pipeline is connected to the first input end, and the gasification output end of the supercritical hydrothermal synthesis reactor 12 is connected to the second input end; the output end of the oxidation reactor 14 is connected to a gas-liquid separator 9 after passing through the first heat exchanger 5, the second heat exchanger 6 and the third heat exchanger 7 in sequence.

[0040] Among them, a third cooler 18 is provided between the third heat exchanger 7 and the gas-liquid separator 9 .

[0041] The structural principle in this embodiment is as follows: After the water pump 1 is started, the water flow is pumped into the water output pipeline to provide the system with the necessary water flow and pressure. When the water flow passes through the first heat exchanger 5, it exchanges heat with the hot air flow from the oxidation reactor 14, thereby preheating the hot air flow, which helps to improve the temperature efficiency of the subsequent reaction.

[0042] The slurry pump 3 pumps the food waste into the food waste output pipeline in the form of slurry to provide necessary materials for the subsequent oxidation reaction. Before the food waste slurry enters the oxidation reactor 14, it is preheated by the third heat exchanger 7 to improve the reaction efficiency.

[0043] The liquid oxygen pump 2 provides the necessary pressure and flow for the liquid oxygen output pipeline to ensure that the liquid oxygen can be stably delivered to the system; the air preheater 4 uses the heat of the air to preheat the liquid oxygen, so that the liquid oxygen is converted into oxygen, and the oxygen is heated again after passing through the second heat exchanger 6 and passes through the oxidation reactor 14.

[0044] In summary, the present embodiment provides a kitchen waste gasification and supercritical hydrothermal synthesis copper powder preparation and processing system, which realizes the effective utilization of waste by inputting kitchen waste as raw materials, and reduces the environmental pollution caused by landfill and incineration. The kitchen waste can be converted into valuable energy or intermediate products after gasification treatment in the supercritical water gasification reactor 10, thereby improving the recycling rate of resources. Copper powder is prepared by the supercritical hydrothermal synthesis reactor 12, and the hydrogen-rich gas produced by gasification can directly replace the reducing agent to reduce the ultrafine copper powder. The water output pipeline, the kitchen waste output pipeline and the liquid oxygen output pipeline are preheated in sequence by the oxidation reactor 14. The present invention integrates the two processes of kitchen waste gasification and supercritical hydrothermal synthesis of copper powder. The water output pipeline, the kitchen waste output pipeline, the liquid oxygen output pipeline, the supercritical water gasification reactor unit, the copper solution output unit, the oxidation reactor 14 and the liquid-solid separator 17 and other modules work together to effectively improve the efficiency of preparing ultrafine copper powder.

[0045] Example 2 This embodiment provides a method for preparing copper powder by gasification and supercritical hydrothermal synthesis of kitchen waste, based on the above-mentioned system for preparing copper powder by gasification and supercritical hydrothermal synthesis of kitchen waste, including the following steps: The kitchen waste slurry and water are driven by the slurry pump 3 of the kitchen waste output pipeline and the water pump 1 of the water output pipeline, respectively, and then preheated by the first heat exchanger 5 and the third heat exchanger 7, respectively, and then input into the supercritical water gasification reactor 10; The heating device 11 outside the supercritical water gasification reactor 10 is turned on for the system startup process, and is turned off after the system runs smoothly. The gasification product in the supercritical water gasification reactor 10 flows into the supercritical water thermal synthesis reactor 12 as a reducing agent and heat source after ash separation.

[0046] When the supercritical water gasification reactor 10 is discharged, the water injection ball valve of the lock hopper 19 is opened, water is injected into the lock hopper 19 to a certain pressure, and then the ball valve is closed. The discharge needle valve is then quickly opened. The supercritical water in the supercritical water gasification reactor 10 transports the slag particles at the bottom of the supercritical water gasification reactor 10 to the first cooler 8 for cooling, and then the mixture enters the lock hopper 19. When the pressure of the entire system reaches equilibrium, the discharge needle valve will be closed. At this time, the lock hopper 19 is completely isolated from the reactor system. The water injection ball valve is then opened, and the liquid-solid mixture in the lock hopper 19 is discharged.

[0047] Start the copper precursor solution pump 15 and the alkaline solution pump 16 to input the precursor compound solution (CuSO4, Cu(NO3)2, Cu(HCOO)2 and other precursors) and the alkaline solution (NaOH, KOH and other modifiers) as particle modifiers into the supercritical hydrothermal synthesis reactor 12. The product flows through the second cooler 13 for water cooling and can be separated in the liquid-solid separator 17 to obtain ultrafine copper powder.

[0048] Liquid oxygen is pressurized by the liquid oxygen pump 2, flows through the air preheater 4 and the second heat exchanger 6 for preheating, and then enters the oxidation reactor 14. The remaining product from the supercritical hydrothermal synthesis reactor 12 enters the oxidation reactor 14 to react with oxygen, releasing heat to increase the enthalpy of the mixed product, and the mixed product flows into the first heat exchanger 5, the second heat exchanger 6 and the third heat exchanger 7 in sequence, and passes through the third cooler 18 and then into the gas-liquid separator 9 to obtain hydrogen.

[0049] In this embodiment, the supercritical water gasification reactor 10 is connected to the supercritical hydrothermal synthesis reactor 12, and the hydrogen-rich gas produced by gasification can directly replace the reducing agent to reduce the ultrafine copper powder, thereby reducing the production cost and shortening the reaction time of the supercritical hydrothermal synthesis. The remaining gas enters the oxidation reactor 14 for oxidation to provide heat for the gasification reactor. This method is suitable for the case where the ultrafine copper powder is the main product and hydrogen is the byproduct.

[0050] In this embodiment, the hydrogen produced by the supercritical water gasification of food waste can directly participate in the subsequent supercritical hydrothermal synthesis process, replacing expensive reducing agents. This method significantly shortens the reaction time of supercritical hydrothermal synthesis and reduces the dependence on traditional chemical reducing agents. Reduces production costs. The supercritical water gasification process and the supercritical hydrothermal synthesis process are easy to control. Clean, efficient, low-cost and continuously controllable preparation of ultrafine copper powder is achieved. Compared with the traditional liquid phase method for preparing ultrafine copper powder, the thermal solvent effect of supercritical water can dissolve a variety of organic chemicals to form a homogeneous reaction system, thereby greatly improving the reaction rate. By adjusting the dissolution behavior of supercritical water, rapid supersaturation of solutes can be achieved. The nucleation and growth of copper powder are promoted, and its surface properties can also be fine-tuned. Through supercritical water gasification technology, food waste is effectively converted into hydrogen, realizing the high value of waste. In addition, this treatment method effectively reduces the cost of food waste treatment. At the same time, the use of supercritical water gasification technology to convert food waste into hydrogen promotes the green development of the economy.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis of copper powder, characterized in that: It includes a water output pipeline, a kitchen waste output pipeline, a supercritical water gasification reactor unit, a supercritical hydrothermal synthesis reactor (12), a copper solution output unit, a liquid oxygen output pipeline, an oxidation reactor (14), and a liquid-solid separator (17); The output ends of the water output pipeline and the kitchen waste output pipeline are respectively connected to the input end of the supercritical water gasification reactor unit; the output end of the supercritical water gasification reactor unit is connected to the input end of the supercritical hydrothermal synthesis reactor (12); The input end of the copper solution output unit is used to input a copper precursor solution and an alkaline solution, and the output end is connected to the input end of a supercritical hydrothermal synthesis reactor (12); the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor (12) is connected to the input end of a liquid-solid separator (17); The output end of the liquid oxygen output pipeline and the gasification output end of the supercritical hydrothermal synthesis reactor (12) are respectively connected to the input end of the oxidation reactor (14); the output end of the oxidation reactor (14) passes through the water output pipeline, the food waste output pipeline and the liquid oxygen output pipeline in sequence, and is used to preheat the water output pipeline, the food waste output pipeline and the liquid oxygen output pipeline.

2. A kitchen waste gasification and supercritical hydrothermal synthesis copper powder preparation and processing system according to claim 1, characterized in that: The supercritical water gasification reactor unit comprises a supercritical water gasification reactor (10); The input end of the supercritical water gasification reactor (10) is respectively connected to the output ends of the water output pipeline and the food waste output pipeline; the output end of the supercritical water gasification reactor (10) is connected to the input end of the supercritical hydrothermal synthesis reactor (12); wherein the outer wall of the supercritical water gasification reactor (10) is provided with a heating device (11).

3. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 2, characterized in that: A slag discharge port is also provided at the bottom of the supercritical water gasification reactor (10), and the output end of the slag discharge port is connected to a lock hopper (19); wherein a first cooler (8) is provided between the supercritical water gasification reactor (10) and the lock hopper (19).

4. A kitchen waste gasification and supercritical hydrothermal synthesis copper powder preparation and processing system according to claim 3, characterized in that: The lock hopper (19) is provided with a water injection pipeline and a slag discharge pipeline, wherein the water injection pipeline is provided with a water injection ball valve, and the slag discharge pipeline is provided with a slag discharge needle valve.

5. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 1, characterized in that: The copper solution output unit includes a copper precursor solution pipeline and an alkaline solution pipeline; The input end of the copper precursor solution pipeline is provided with a copper precursor solution pump (15) for inputting the copper precursor solution; the input end of the alkaline solution pipeline is provided with an alkaline solution pump (16) for inputting the alkaline solution; The output ends of the copper precursor solution pipeline and the alkaline solution pipeline are respectively connected to the input end of the supercritical hydrothermal synthesis reactor (12).

6. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 1, characterized in that: A second cooler (13) is provided between the liquid-solid mixture output end of the supercritical hydrothermal synthesis reactor (12) and the input end of the liquid-solid separator (17).

7. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 1, characterized in that: The water output pipeline is provided with a water pump (1) and a first heat exchanger (5) in sequence; the kitchen waste output pipeline is provided with a slurry pump (3) and a third heat exchanger (7) in sequence; and the liquid oxygen output pipeline is provided with a liquid oxygen pump (2), an air preheater (4) and a second heat exchanger (6) in sequence.

8. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 7, characterized in that: The oxidation reactor (14) is provided with a first input end and a second input end; wherein the output end of the liquid oxygen output pipeline is connected to the first input end, and the gasification output end of the supercritical hydrothermal synthesis reactor (12) is connected to the second input end; the output end of the oxidation reactor (14) is connected to a gas-liquid separator (9) after passing through a first heat exchanger (5), a second heat exchanger (6) and a third heat exchanger (7) in sequence.

9. The system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to claim 8, characterized in that: A third cooler (18) is provided between the third heat exchanger (7) and the gas-liquid separator (9).

10. A method for preparing copper powder by gasification of kitchen waste and supercritical hydrothermal synthesis, characterized in that: A system for preparing and treating kitchen waste gasification and supercritical hydrothermal synthesis copper powder according to any one of claims 1 to 9 comprises the following steps: The kitchen waste slurry and water are respectively preheated through the kitchen waste output pipe and the water output pipe, and then input into the supercritical water gasification reactor unit; The gasification product in the supercritical water gasification reactor unit flows into the supercritical water thermal synthesis reactor (12) as a reducing agent and a heat source after ash separation; An alkaline solution is used as a particle modifier and a copper precursor solution and is input into a supercritical hydrothermal synthesis reactor (12) through a copper solution output unit, and reacted with a reducing agent in the supercritical hydrothermal synthesis reactor (12), wherein the liquid in the supercritical hydrothermal synthesis reactor (12) flows into a liquid-solid separator (17) and is separated by the liquid-solid separator (17) to obtain ultrafine copper powder; the remaining product in the supercritical hydrothermal synthesis reactor (12) enters an oxidation reactor (14), and liquid oxygen is input into the oxidation reactor (14) through a liquid oxygen output pipeline, and an oxidation reaction is carried out with the remaining product to release heat, and the heat is used to preheat the water output pipeline, the kitchen waste output pipeline and the liquid oxygen output pipeline in turn.

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