Straw pyrolysis tar recycling and carbonization equipment and straw pyrolysis tar recycling carbonization method

Abstract

This invention discloses a straw pyrolysis tar recycling and carbonization device and a method for increasing carbon content in straw pyrolysis tar recycling, relating to the field of agricultural machinery technology. The straw pyrolysis tar recycling and carbonization device includes a pretreatment system, a pyrolysis system, a separation system, and a pumping system. The pretreatment system, with an internal temperature of 200℃~300℃, is used to bake the straw. The pyrolysis system enables the pre-baked straw to pyrolyze, producing biochar and pyrolysis gas. The separation system separates the tar. The pumping system transports and sprays the tar onto the pre-baked straw to form a pre-baked straw-tar mixture, allowing the tar to pyrolyze again, achieving zero tar emissions. The straw pyrolysis tar recycling and carbonization method of this invention solves the problem of difficult tar removal from pyrolysis gas, while simultaneously generating tar carbon, thus achieving a carbon-enhancing effect.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and in particular to a straw pyrolysis tar recycling and carbonization device and a method for increasing the carbon content of straw pyrolysis tar in a furnace. Background Technology

[0002] Currently, a large amount of straw resources are being abandoned and burned, causing environmental pollution. Pyrolysis carbonization technology can effectively convert straw into biochar, achieving efficient utilization of straw resources, reducing carbon emissions, and protecting the environment. Therefore, straw pyrolysis carbonization and the application of straw char have received widespread attention.

[0003] Continuous biomass pyrolysis cogeneration technology is widely used in straw pyrolysis carbonization due to its continuous production and ease of large-scale application. However, problems such as difficulty in removing tar from the pyrolysis gas and the potential for secondary pollution have hindered the further promotion and application of straw pyrolysis carbonization technology. Summary of the Invention

[0004] The purpose of this invention is to provide a straw pyrolysis tar recycling and carbonization device and a method for recycling straw pyrolysis tar to increase carbon content, which can separate tar from the pyrolysis gas and re-pyrolyze the tar to achieve zero tar emissions, thereby solving the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a straw pyrolysis tar recycling and carbonization device, comprising a pretreatment system, a pyrolysis system, a separation system, and a pumping system. The pretreatment system has an internal temperature of 200℃~300℃ and is used to bake the straw. The pyrolysis system is provided with a pyrolysis inlet and a pyrolysis outlet. The pyrolysis inlet is connected to the straw outlet and can receive the pre-baked straw output from the pretreatment system. The pyrolysis system can pyrolyze the pre-baked straw to produce biochar and pyrolysis gas. The pyrolysis outlet can discharge the biochar and pyrolysis gas. The separation system can separate the tar from the pyrolysis gas. The pumping system is connected to the separation system and can transport the tar to the pyrolysis inlet and spray it onto the pre-baked straw to form a pre-baked straw-tar mixture.

[0006] In some embodiments, the separation system includes a solid-gas separation system and a gas-liquid separation system; the solid-gas separation system includes a solid-gas separation chamber and a carbon collection box, the solid-gas separation chamber has a material inlet at the top of its side wall, a biochar outlet at the bottom of the solid-gas separation chamber, the carbon collection port of the carbon collection box is sealed to the biochar outlet, the solid-gas separation chamber has a pyrolysis gas outlet at the top, and the pyrolysis gas outlet is located away from the material inlet, and the pyrolysis gas outlet is connected to the gas-liquid separation system; the gas-liquid separation system includes a condensation device and a gas-liquid separation chamber. The condensing device is used to absorb heat in the gas-liquid separation chamber. A pyrolysis gas inlet is provided on one side of the gas-liquid separation chamber, and a non-condensable gas outlet, a light liquid outlet, and a heavy liquid outlet are provided on the other side of the gas-liquid separation chamber. The non-condensable gas outlet, the light liquid outlet, and the heavy liquid outlet are arranged sequentially from top to bottom on the side wall of the gas-liquid separation chamber. The pyrolysis gas inlet is connected to the pyrolysis gas outlet, and the heavy liquid outlet is used to supply the tar. The heavy liquid outlet is connected to the pumping system to transport the tar.

[0007] In some embodiments, the straw pyrolysis tar recycling carbonization device further includes a combustion system connected to the non-condensable gas outlet. The combustion system includes a combustion device and a heat transfer pipe connected to the combustion device. The non-condensable gas is burned at the combustion device to generate high-temperature flue gas. The heat transfer pipe includes a first branch. The pyrolysis system has a flue gas inlet near the pyrolysis outlet. The first branch is connected to the flue gas inlet and can introduce flue gas into the pyrolysis system to provide heat for the pyrolysis of the pre-baked straw-tar mixture.

[0008] In some embodiments, the solid-gas separation chamber includes a material level control device and a baffle. The material level control device controls the discharge rate of the biochar to ensure a biochar layer exists at the bottom of the solid-gas separation chamber. The baffle is vertically arranged in the solid-gas separation chamber, dividing it vertically into a first chamber and a second chamber. The material inlet is located at the top of the side wall of the first chamber. The lower part of the baffle is inserted into the biochar layer and spaced apart from the bottom of the solid-gas separation chamber. The first chamber and the second chamber are connected below the baffle, allowing the pyrolysis gas to enter the second chamber from the first chamber through the biochar layer. The second chamber has a pyrolysis gas outlet at the top, which is connected to the gas-liquid separation system. The heat transfer pipe also includes a second branch, which provides heat to the biochar layer.

[0009] In some embodiments, the pretreatment system includes a pretreatment channel, a straw conveying assembly, and a blade assembly. The internal temperature of the pretreatment channel is 200℃~300℃. The pretreatment channel is provided with a straw inlet for passing through bundles of straw and a straw outlet with an opening facing downwards, which can bake the bundles of straw. The straw conveying assembly is disposed in the pretreatment channel and is used to transport the bundles of straw from the straw inlet to the straw outlet. The blade assembly is disposed at the straw outlet and is used to break the bundles of straw and crush them to form pre-baked straw powder.

[0010] In some embodiments, the straw pyrolysis tar recycling carbonization device further includes a conveying mechanism, which includes a connecting channel, a distributor, and a driving device. The connecting channel has its inlet end sealed to the straw outlet and its outlet end sealed to the pyrolysis inlet. The connecting channel is used to convey the pre-baked straw powder. The distributor is located at the pyrolysis inlet and is used to convey the pre-baked straw powder to the pyrolysis system. A spraying mechanism is provided at the end of the pumping system, and the output end of the spraying mechanism faces the surface of the distributor to spray the tar onto the pre-baked straw powder. The driving device is connected to the distributor and is used to drive the distributor.

[0011] In some embodiments, the pyrolysis system includes a rotary kiln, a high-temperature flue chamber, and an exhaust duct. The inlet of the rotary kiln is the pyrolysis inlet, and the outlet of the rotary kiln is the pyrolysis outlet. The rotary kiln is rotatably disposed within the high-temperature flue chamber. The flue gas inlet is located on the side wall of the high-temperature flue chamber near the outlet of the rotary kiln to provide heat to the rotary kiln. The exhaust duct includes a waste heat inlet and a waste heat outlet. The waste heat inlet is located on the side wall of the high-temperature flue chamber near the inlet of the rotary kiln and communicates with the high-temperature flue chamber. The waste heat outlet is located on the side wall of the pretreatment channel near the straw outlet and communicates with the pretreatment channel to discharge the flue gas with waste heat from the pyrolysis system into the pretreatment channel for baking the bundled straw.

[0012] In some embodiments, the pretreatment system is a pusher furnace, the straw inlet is the inlet of the pusher furnace, and the straw outlet is the outlet of the pusher furnace; the pretreatment system also includes a flue gas outlet and an induced draft fan, the flue gas outlet is located at one end of the inlet of the pusher furnace, and the induced draft fan is located at the flue gas outlet to guide the flue gas with residual heat in the pusher furnace to be discharged through the flue gas outlet.

[0013] In some embodiments, the blade assembly includes a rotating shaft, a set of swivel blades, and a motor. The rotating shaft is rotatably mounted on the side wall of the pretreatment channel. The swivel blades are detachably connected to the rotating shaft. The motor is connected to the rotating shaft and drives the rotating shaft to rotate so that the swivel blades break up and crush the bundled straw.

[0014] The present invention also provides a method for increasing carbon content in straw pyrolysis tar by recycling it using the above-mentioned straw pyrolysis tar recycling carbonization device, comprising: The straw is baked using the pretreatment system. The pre-baked straw is received through the pyrolysis system to pyrolyze the pre-baked straw and generate the biochar; The waste heat from the pyrolysis system is discharged to the pretreatment channel to provide heat for baking the straw. The tar is separated by the separation system and pumped to the pyrolysis inlet, and then sprayed onto the pre-baked straw to allow the tar to be pyrolyzed again.

[0015] The present invention achieves the following technical effects compared to the prior art: This invention provides a straw pyrolysis tar recycling and carbonization device. The device separates the tar from the pyrolysis gas through a separation system, then pumps and sprays the tar onto pre-baked straw, which then enters the pyrolysis system for further pyrolysis. After this second pyrolysis, the large tar molecules are depolymerized, producing more light combustible gases such as CH4 and CO, thus increasing the calorific value and yield of the pyrolysis gas. Furthermore, the depolymerization process also involves condensation reactions, forming some tar carbon, which has a carbon-enhancing effect, thereby achieving zero tar emissions.

[0016] The present invention also provides a method for recycling straw pyrolysis tar to increase carbon content, which solves the problems of difficulty in removing tar from pyrolysis gas and easy generation of secondary pollution during straw pyrolysis, achieves zero emission of tar, and also has the effect of increasing carbon content due to the generation of tar carbon. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the straw pyrolysis tar recycling and carbonization device in Embodiment 1 of the present invention; Figure 2 This is a flowchart of the straw pyrolysis tar recycling and carbonization method in Embodiment 2 of the present invention.

[0019] In the diagram: 100-Straw pyrolysis tar recycling carbonization device; 1-Pretreatment system; 11-Pretreatment channel; 111-Flue gas outlet; 12-Knife assembly; 2-Pyrolysis system; 21-Rotary furnace; 22-High temperature flue chamber; 23-Exhaust duct; 3-Separation system; 31-Solid-gas separation chamber; 311-Biochar layer; 312-Baffle; 313-Pyrolysis gas outlet; 32-Carbon collection box; 33-Gas-liquid separation chamber; 331-Pyrolysis gas inlet; 332-Non-condensable gas outlet; 333-Light liquid outlet; 334-Heavy liquid outlet; 4-Pumping system; 5-Combustion system; 6-Conveying mechanism; 61-Connecting channel; 62-Distributor; 63-Drive device. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide a straw pyrolysis tar recycling and carbonization device and a method for recycling straw pyrolysis tar to increase carbon content, which can separate tar from the pyrolysis gas and re-pyrolyze the tar to achieve zero tar emissions, thereby solving the problems existing in the prior art.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the following description is provided in conjunction with the accompanying drawings. Figures 1-2 The present invention will be further described in detail below with reference to specific embodiments.

[0023] Example 1 This embodiment provides a straw pyrolysis tar recycling and carbonization device 100, see reference. Figure 1The system includes a pretreatment system 1, a pyrolysis system 2, a separation system 3, and a pumping system 4. The pretreatment system 1 has an internal temperature of 200℃~300℃ and is used to bake straw. The pyrolysis system 2 is equipped with a pyrolysis inlet and a pyrolysis outlet. The pyrolysis inlet is connected to the pretreatment system and can receive the pre-baked straw output from the pretreatment system 1. The pyrolysis system 2 can pyrolyze the pre-baked straw to produce biochar and pyrolysis gas, and the pyrolysis outlet can discharge the biochar and pyrolysis gas. The separation system 3 can separate the tar from the pyrolysis gas. The pumping system 4 is connected to the separation system 3 and can transport the tar to the pyrolysis inlet and spray it onto the pre-baked straw to form a pre-baked straw-tar mixture. In this embodiment, by baking the straw under the conditions of 200℃~300℃ in the pretreatment system, the straw fibers are partially broken due to the high temperature, the micropores increase, and the specific surface area increases, which is conducive to the full pyrolysis of the straw and can also improve the quality of the pyrolysis gas produced by the straw pyrolysis. Furthermore, by separating the tar from the pyrolysis gas through separation system 3, the tar is then pumped and sprayed onto pre-baked straw, and together with the pre-baked straw, it enters pyrolysis system 2 for further pyrolysis. After this second pyrolysis, the large tar molecules depolymerize, producing more light combustible gases such as CH4 and CO, which can improve the calorific value and yield of the pyrolysis gas. On the other hand, the tar also undergoes a condensation reaction during depolymerization, forming some tar carbon, which has a carbon-enhancing effect, thus achieving zero tar emissions.

[0024] In some implementations, reference Figure 1The separation system 3 includes a solid-gas separation system and a gas-liquid separation system. The solid-gas separation system includes a solid-gas separation chamber 31 and a carbon collection box 32. A material inlet is located at the top of the side wall of the solid-gas separation chamber 31, and a biochar outlet is located at the bottom of the solid-gas separation chamber 31. The carbon collection port of the carbon collection box 32 is sealed to the biochar outlet. A pyrolysis gas outlet 313 is located at the top of the solid-gas separation chamber 31, and the pyrolysis gas outlet 313 is located away from the material inlet. The pyrolysis gas outlet 313 is connected to the gas-liquid separation system 3. The gas-liquid separation system includes a condensation device and the gas-liquid separation chamber 33. The condensation device is used for... The gas-liquid separation chamber 33 absorbs heat from the gas-liquid separation chamber. One side of the chamber has a pyrolysis gas inlet 331, and the other side has a non-condensable gas outlet 332, a light liquid outlet 333, and a heavy liquid outlet 334. These outlets are arranged sequentially from top to bottom on the side wall of the chamber. The pyrolysis gas inlet 331 is connected to the pyrolysis gas outlet 313, and the heavy liquid outlet 334 supplies tar. The heavy liquid outlet 334 is connected to the pumping system 4 to transport the tar. By setting up a solid-gas separation system to separate biochar and pyrolysis gas, and by separating non-condensable and condensable gases through the gas-liquid separation system, and by separating tar from the heavy liquid outlet 334 through the design of the light liquid outlet 333 and the heavy liquid outlet 334, the separation of tar and non-condensable gases in the pyrolysis gas is achieved, allowing the tar to be subsequently pumped onto the pre-baked straw at the pyrolysis inlet. In this embodiment, the refrigeration device uses a refrigeration coil filled with refrigerant, which is spirally wound around the outer wall of the gas-liquid separation chamber 33 to absorb heat from the gas-liquid separation chamber 33 through heat exchange. In other embodiments, a refrigeration device may also be installed inside the gas-liquid separation chamber 33, or other forms of refrigeration devices may be used to absorb heat from the gas-liquid separation chamber 33.

[0025] In some implementations, reference Figure 1The straw pyrolysis tar recycling carbonization device 100 also includes a combustion system 5 connected to the non-condensable gas outlet 332. The combustion system 5 includes a combustion device and a heat transfer pipe connected to the combustion device. The non-condensable gas burns at the combustion device to generate high-temperature flue gas. The heat transfer pipe includes a first branch. A flue gas inlet is provided near the pyrolysis outlet of the pyrolysis system 2. The first branch is connected to the flue gas inlet, allowing flue gas to be introduced into the pyrolysis system 2 to provide heat for the pyrolysis of the pre-baked straw-tar mixture. By setting up the combustion system 5 and connecting the non-condensable gas outlet 332 to the combustion system 5, the high-temperature flue gas generated by the combustion of the non-condensable gas is connected to the flue gas inlet to provide heat for the pyrolysis of the pre-baked straw-tar mixture. This achieves full utilization of the pyrolysis gas and saves energy consumption of the pyrolysis system 2 by using the heat from the combustion of the non-condensable gas, thus reducing the energy consumption of the pre-baked straw-tar mixture pyrolysis. In this embodiment, the combustion device includes an igniter and an air distribution pipe. The igniter is used to ignite the non-condensable gas, and the air distribution pipe provides oxygen for the combustion of the non-condensable gas. In some other embodiments, the combustion system 5 may also include an online gas analyzer to more accurately supply oxygen for the combustion of the non-condensable gas based on its composition and the content of each component.

[0026] In some implementations, reference Figure 1The solid-gas separation chamber 31 includes a material level control device and a baffle 312. The material level control device controls the discharge of biochar to ensure that a biochar layer 311 exists at the bottom of the solid-gas separation chamber 31. The baffle 312 is vertically installed in the solid-gas separation chamber 31, dividing the solid-gas separation chamber 31 vertically into a first chamber and a second chamber. The material inlet is located at the top of the side wall of the first chamber. The lower part of the baffle 312 is inserted into the biochar layer 311 and spaced apart from the bottom of the solid-gas separation chamber 31. The first chamber and the second chamber are connected below the baffle 312 so that pyrolysis gas can enter the second chamber from the first chamber through the biochar layer 311. A pyrolysis gas outlet 313 is opened at the top of the second chamber and is connected to the gas-liquid separation system. The heat transfer pipe also includes a second branch, which provides heat to the biochar layer 311. By setting a material level controller, a biochar layer 311 is present at the bottom of the solid-gas separation chamber 31. When pyrolysis gas is introduced into the biochar layer 311, the pyrolysis gas and biochar undergo an autocatalytic activation reaction. On the one hand, the biochar catalyzes the depolymerization of large tar molecules in the pyrolysis gas, producing more light combustible gases, such as CH4 and CO. On the other hand, CO2 and H2O in the pyrolysis gas have an activation effect on the biochar, which can increase the specific surface area of ​​the biochar, improve the pore structure of the biochar, enhance the water and fertilizer retention capacity of the biochar, and promote soil ecological health. In this embodiment, the material level controller includes a valve and a distance sensor. The distance sensor is installed on the top inner side of the solid-gas separation chamber 31 to monitor the accumulation height of biochar at the bottom of the solid-gas separation chamber 31. When the accumulation height exceeds a preset maximum value, the valve is opened to allow the biochar to enter the carbon collection box 32. When the accumulation height reaches a preset minimum value, the valve is closed. In this embodiment, the second branch includes a heat-conducting coil, which is wound around the bottom of the solid-gas separation chamber 31 to provide heat to the biochar layer 311 through heat conduction. In other embodiments, other methods can be used, such as adding a heating chamber on the outside of the bottom of the solid-gas separation chamber 31 and connecting the second branch to the heating chamber to heat the bottom of the solid-gas separation chamber 31.

[0027] In some embodiments, the pretreatment system 1 includes a pretreatment channel 11, a straw conveying assembly, and a blade assembly 12. The internal temperature of the pretreatment channel is 200℃~300℃. The pretreatment channel 11 is provided with a straw inlet for passing through bundled straw and a straw outlet with its opening facing downwards, which can bake the bundled straw. The straw conveying assembly is located inside the pretreatment channel 11 and is used to transport the bundled straw from the straw inlet to the straw outlet. The blade assembly 12 is located at the straw outlet and is used to break and crush the bundled straw to form straw pretreatment powder. In this invention, the bundled straw is directly fed into the pretreatment system 1 for baking, and then broken and crushed by the blade assembly 12. Because the straw becomes brittle after baking and is easier to break apart, while undried straw is tougher and more difficult to break, resulting in higher energy consumption, this invention directly bakes the bundled straw before breaking and crushing it, which can reduce processing energy consumption and processing costs compared to the method of first crushing the straw to a certain particle size and then sending it to the reactor for pyrolysis and carbonization. Furthermore, the roasted straw, due to the high temperature causing partial breakage of straw fibers, increases microscopic porosity and specific surface area, which is beneficial for the complete pyrolysis of the straw and also improves the quality of the pyrolysis gas produced. In some other embodiments, the pretreatment channel 11 can also be equipped with a heating device for roasting the straw, so as to prevent the temperature in the pretreatment channel 11 from decreasing, resulting in poor pre-roasting effect of the straw and affecting the quality of the subsequently generated pyrolysis gas.

[0028] In some implementations, reference Figure 1The straw pyrolysis tar recycling carbonization device 100 also includes a conveying mechanism 6, which includes a connecting channel 61, a distributor 62, and a driving device 63. The inlet end of the connecting channel 61 is sealed to the straw outlet, and the outlet end of the connecting channel 61 is sealed to the pyrolysis inlet. The connecting channel 61 is used to convey pre-baked straw powder. The distributor 62 is located at the pyrolysis inlet and is used to convey pre-baked straw powder to the pyrolysis system 2. A spraying mechanism is provided at the end of the pumping system 4, and the output end of the spraying mechanism faces the surface of the distributor 62 to spray tar onto the pre-baked straw powder. The driving device 63 is connected to the distributor 62 and is used to drive the distributor 62. By setting the connecting channel 61, the inlet end of the connecting channel 61 is sealed to the straw outlet, and the outlet end of the connecting channel 61 is sealed to the pyrolysis inlet. This ensures that flue gas will not overflow from the connecting channel 61, avoiding environmental pollution, and also prevents pre-baked straw powder from flying out and affecting the working environment of on-site personnel. By setting up a feeder 62, the drive device 63 drives the feeder 62 to distribute material into the pyrolysis system 2, allowing the pre-baked straw powder to smoothly enter the pyrolysis system 2. In this embodiment, the feeder 62 is a feeding plate and is arranged at an angle. The drive device 63 includes a drive motor, a cam, and a connecting rod. One end of the connecting rod is hinged to the edge of the cam, and the other end is hinged to the top of the feeder 62. The bottom of the feeder 62 is rotatably connected to the pyrolysis inlet. The output end of the drive motor is connected to one side of the cam to drive the cam to rotate. The rotation of the cam drives the connecting rod to move, thereby causing the top of the feeder 62 to shake up and down, thus shaking the pre-baked straw powder on the feeder 62 into the pyrolysis system 2, achieving uniform distribution of the pre-baked straw powder, thereby making the pre-baked straw powder more evenly heated and pyrolyzed, and improving the quality of the pyrolysis gas. In this embodiment, the pumping system 4 includes a delivery pump and a delivery pipeline. The delivery pump can be a peristaltic pump, centrifugal pump, or other pump capable of providing delivery pressure. The spraying mechanism is a nozzle with a spraying pressure between 0.2 MPa and 0.5 MPa. High-pressure spraying, accompanied by the vibration of the spreader 62, ensures that the tar is evenly sprayed onto the straw surface for uniform pyrolysis. In other embodiments, the spreader 62 can be a spraying shaft driven by a drive device 63, with spraying blades on the shaft. The pre-baked straw powder enters the pyrolysis system 2 evenly under the spraying action of the blades. In other embodiments, the spreader 62 can also be any other structure capable of achieving uniform distribution of material into the pyrolysis system 2.

[0029] In some implementations, reference Figure 1The pyrolysis system 2 includes a rotary kiln 21, a high-temperature flue chamber 22, and an exhaust duct 23. The inlet of the rotary kiln 21 is the pyrolysis inlet, and the outlet of the rotary kiln 21 is the pyrolysis outlet. The rotary kiln 21 is rotatably disposed inside the high-temperature flue chamber 22. The flue gas inlet is located on the side wall of the high-temperature flue chamber 22 near the outlet of the rotary kiln 21 to provide heat to the rotary kiln 21. The exhaust duct 23 includes a waste heat inlet and a waste heat outlet. The waste heat inlet is located on the side wall of the high-temperature flue chamber 22 near the inlet of the rotary kiln 21 and is connected to the high-temperature flue chamber 22. The waste heat outlet is located on the side wall of the pretreatment channel 11 near the straw outlet and is connected to the pretreatment channel 11 to discharge the flue gas with waste heat in the pyrolysis system 2 to the pretreatment channel 11 for baking the bundled straw. By setting up the exhaust duct 23, the heat generated after the combustion of non-condensable gases first heats the rotary kiln 21 to provide heat for the pyrolysis reaction of the pre-baked straw powder-tar mixture. The residual heat enters the pretreatment channel 11 through the exhaust duct 23 to provide heat for the baking of bundled straw, thus realizing the step utilization of heat and avoiding the waste of heat generated after the combustion of non-condensable gases.

[0030] In some implementations, reference Figure 1 The pretreatment system 1 is a pusher plate furnace, with the straw inlet serving as the furnace's inlet and the straw outlet as its outlet. The pretreatment system 1 also includes a flue gas outlet 111 and an induced draft fan. The flue gas outlet 111 is located at one end of the pusher plate furnace's inlet, and the induced draft fan is located at the outlet 111 to guide the residual heat-laden flue gas from the furnace through the outlet 111. The pusher plate furnace contains pusher plates, guide rails, and a propulsion system that provides driving force to the pusher plates. Guided by the guide rails, the pusher plates are propelled, and bundles of straw placed on the pusher plates move from the furnace inlet to the outlet. The pretreatment system 1 can also be a chain grate furnace or other furnace types. The induced draft fan guides the flue gas out of the outlet 111. In this embodiment, the outlet 111 is also equipped with a dust removal device or filter to remove dust from the flue gas, ensuring that the discharged flue gas remains within legal limits and preventing environmental pollution. Exhaust fans can also be installed at other locations within the pretreatment channel 11 to guide the flow of flue gas within the pretreatment channel 11.

[0031] In some implementations, reference Figure 1The blade assembly 12 includes a rotating shaft, a set of swivel blades, and a motor. The rotating shaft is rotatably mounted on the side wall of the pretreatment channel 11. The swivel blades are detachably connected to the rotating shaft. The motor is connected to the rotating shaft and drives it to rotate, so that the swivel blades can break and crush the bundled straw. The swivel blades allow the bundled straw to be crushed into smaller particles, facilitating complete pyrolysis. The detachable swivel blades on the rotating shaft allow for adjustment of the blade distribution according to the size of the bundled straw, ensuring thorough crushing. The detachable connection of the swivel blades to the rotating shaft can be via bolts or snap-fit ​​connections. The swivel blades can be a single blade with a fixed base or a ring of blades fixed to an annular base. Furthermore, the blade spacing is 10cm-15cm to ensure thorough crushing of the bundled straw. Even further, both the swivel blades and the rotating shaft are made of high-temperature resistant materials to withstand high-temperature working environments.

[0032] In some other implementations, refer to Figure 1 The gas-liquid separation system also includes a wood vinegar collection device, which is connected to the light liquid outlet 333 to collect the condensed wood vinegar. The separated wood vinegar can then be used in agriculture or animal husbandry, avoiding the waste of production resources.

[0033] Example 2 This embodiment provides a method for increasing the carbon content of straw pyrolysis tar by recycling it into a furnace using the straw pyrolysis tar recycling carbonization device 100 of Embodiment 1. (Refer to...) Figure 2The flowchart includes: baking the input straw through a pretreatment system 1; receiving the pre-baked straw through a pyrolysis system 2 to pyrolyze the pre-baked straw and generate biochar; discharging the waste heat of the pyrolysis system 2 to the pretreatment channel 11 to provide heat for baking the straw; separating the tar through a separation system 3 and pumping the tar through a pumping system 4 to the pyrolysis inlet and spraying it onto the pre-baked straw to allow the tar to pyrolyze again. In this embodiment, the pyrolysis system 2 uses a rotary kiln 21. During operation, the rotation speed of the rotary kiln 21 is first adjusted and it is ignited for heating. The residual heat from heating enters the pretreatment channel 11 through the exhaust duct 23. After the bundled straw has been baked, the pre-baked straw powder formed by the knife group 12 breaking the bundles and crushing it is evenly fed into the rotary kiln 21 by the feeder 62 for pyrolysis. The pyrolysis gas and biochar generated by pyrolysis enter the solid-gas separation chamber 31 through the material inlet. The biochar remains at the bottom of the solid-gas separation chamber 31, forming a biochar layer 311, and is discharged into the carbon collection box 32 under the action of the material level control device. The pyrolysis gas enters the gas-liquid separation system 3 through the pyrolysis gas outlet 313 and is cooled by the condenser. After condensation and stratification, the non-condensable gas enters the combustion system 5 through the non-condensable gas outlet 332. Part of the heat generated by combustion heats the biochar layer 311, causing the pyrolysis gas to undergo an autocatalytic activation reaction through the biochar layer 311. The other part first provides heat to the rotary kiln 21. The flue gas with residual heat enters the pusher furnace to provide heat for the baking of bundled straw. The wood vinegar enters the wood vinegar collection device through the light liquid outlet 333. The tar enters the pumping system 4 through the heavy liquid outlet 334 and is transported to the top of the distributor 62 of the conveying mechanism 6. It is then sprayed onto the pre-baked straw powder through the nozzle to form a pre-baked straw powder-tar mixture, which enters the rotary kiln 21 for pyrolysis. By spraying tar onto pre-baked straw powder, the mixture of pre-baked straw powder and tar enters the pyrolysis system 2 together, where the tar is pyrolyzed again. After being pyrolyzed again, the large tar molecules are depolymerized, producing more light combustible gases such as CH4 and CO. This increases the calorific value and yield of the pyrolysis gas, solving the problems of difficult tar removal and easy secondary pollution in the pyrolysis gas during straw pyrolysis. It achieves zero tar emissions and also has a carbon-enhancing effect due to the carbon generated by the tar.

[0034] Example 3 This embodiment involves recycling pyrolysis tar from corn stalks for carbon enrichment. First, the rotary kiln 21 is started, using either firewood or diesel ignition to heat the chamber temperature to 600℃. The rotation speed of the rotary kiln 21 is set to ensure a residence time of 40-50 minutes for the pre-baked corn stalk powder within the kiln. Then, whole bales of corn stalks from the field are continuously fed into the inlet of the pusher furnace. After baking within the pusher furnace and being broken up and pulverized by the blade assembly 12, the pre-baked corn stalk powder enters the connecting channel 61 and falls onto the feeder 62. The feeder 62 evenly transports the pre-baked corn stalk powder to the rotary kiln 21. Upon entering the rotary kiln 21, the pre-baked corn stalk powder begins a pyrolysis reaction due to low oxygen and high temperature. The generated pyrolysis gas and biochar enter the solid-gas separation chamber 31 through the material inlet. The biochar remains at the bottom of the solid-gas separation chamber 31, forming a biochar layer 311. Under the control of the position control device, the gas is discharged into the carbon collection box 32. The pyrolysis gas enters the gas-liquid separation system 3 through the pyrolysis gas outlet 313. After being condensed by the condenser, it is separated into layers. The non-condensable gas enters the combustion system 5 through the non-condensable gas outlet 332. Part of the heat generated by combustion is used to heat the biochar layer 311, so that the pyrolysis gas undergoes an autocatalytic activation reaction through the biochar layer 311. The other part first provides heat to the rotary kiln 21. The flue gas with residual heat has a temperature of about 300°C and enters the pusher furnace to provide heat for baking corn stalk bales. The wood vinegar enters the wood vinegar collection device through the light liquid outlet 333. The tar enters the pumping system 4 through the heavy liquid outlet 334 and is transported to the top of the distributor 62 of the conveying mechanism 6. It is sprayed onto the corn pre-baked stalk powder through the nozzle to form a corn pre-baked stalk powder-tar mixture, which enters the rotary kiln 21 for pyrolysis, realizing the re-carbonization of tar and improving the carbon fixation effect.

[0035] Example 4 This embodiment involves the recycling of pyrolysis tar from rice / wheat straw for carbon enrichment. First, the rotary kiln 21 is started, using firewood or diesel ignition to heat the chamber temperature to 550°C. The rotation speed of the rotary kiln 21 is set to ensure the residence time of the pre-baked rice / wheat straw powder within the kiln is 30-40 minutes. Then, bundles of rice / wheat straw from the field are continuously fed into the inlet of the pusher furnace. After baking within the pusher furnace and being broken up and pulverized by the blade assembly 12, the pre-baked rice / wheat straw powder enters the connecting channel 61 and falls onto the feeder 62. The feeder 62 evenly transports the pre-baked rice / wheat straw powder into the rotary kiln 21. Upon entering the rotary kiln 21, the pre-baked rice / wheat straw powder begins a pyrolysis reaction due to low oxygen and high temperature. The generated pyrolysis gas and biochar enter the solid-gas separation chamber 31 through the material inlet. The biochar remains at the bottom of the solid-gas separation chamber 31, forming a biochar layer 31. 1. Under the action of the material level control device, the gas is discharged into the carbon collection box 32. The pyrolysis gas enters the gas-liquid separation system 3 through the pyrolysis gas outlet 313. After being condensed by the condensing device, it is separated into layers. The non-condensable gas enters the combustion system 5 through the non-condensable gas outlet 332. Part of the heat generated by combustion is used to heat the biochar layer 311, so that the pyrolysis gas undergoes an autocatalytic activation reaction through the biochar layer 311. The other part first provides heat to the rotary kiln 21. The flue gas with residual heat has a temperature of about 200°C and enters the pusher furnace to provide heat for baking rice / wheat straw bales. The wood vinegar enters the wood vinegar collection device through the light liquid outlet 333. The tar enters the pumping system 4 through the heavy liquid outlet 334 and is transported to the top of the distributor 62 of the conveying mechanism 6. It is sprayed onto the rice / wheat pre-baked straw powder through the nozzle to form a rice / wheat pre-baked straw powder-tar mixture, which enters the rotary kiln 21 for pyrolysis to achieve tar re-carbonization and improve the carbon fixation effect.

[0036] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A device for recycling straw pyrolysis tar into carbonization furnace, characterized in that, include: A pretreatment system for baking straw; The pyrolysis system is provided with a pyrolysis inlet and a pyrolysis outlet. The pyrolysis inlet is connected to the pretreatment system and can receive the pre-baked straw output by the pretreatment system. The pyrolysis system can pyrolyze the pre-baked straw to produce biochar and pyrolysis gas. The pyrolysis outlet can discharge the biochar and pyrolysis gas. A separation system capable of separating tar from the pyrolysis gas; A pumping system, which is connected to the separation system, is capable of transporting the tar to the pyrolysis inlet and spraying it onto the pre-baked straw to form a pre-baked straw-tar mixture; The separation system includes a solid-gas separation system and a gas-liquid separation system; The solid-gas separation system includes a solid-gas separation chamber and a carbon collection box. The solid-gas separation chamber has a material inlet at the top of its side wall and a biochar outlet at the bottom. The carbon collection port of the carbon collection box is sealed to the biochar outlet. The solid-gas separation chamber has a pyrolysis gas outlet at the top, which is far from the material inlet. The pyrolysis gas outlet is connected to the gas-liquid separation system. The solid-gas separation chamber includes: A material level control device, wherein the material level control device controls the discharge amount of biochar to ensure that a biochar layer exists at the bottom of the solid-gas separation chamber; A baffle is vertically installed in the solid-gas separation chamber, dividing the chamber into a first chamber and a second chamber. The material inlet is located at the top of the side wall of the first chamber. The lower part of the baffle is inserted into the biochar layer and spaced apart from the bottom of the solid-gas separation chamber. The first chamber and the second chamber are connected below the baffle, allowing the pyrolysis gas to enter the second chamber from the first chamber through the biochar layer. The second chamber has a pyrolysis gas outlet at the top, which is connected to the gas-liquid separation system. The pretreatment system includes a pretreatment channel, a straw conveying assembly, and a blade assembly. The internal temperature of the pretreatment channel is 200℃~300℃. The pretreatment channel is provided with a straw inlet for passing through bundled straw and a straw outlet with an opening facing downwards, which can bake the bundled straw. The straw conveying assembly is located in the pretreatment channel and is used to transport the bundled straw from the straw inlet to the straw outlet. The blade assembly is located at the straw outlet and is used to break the bundled straw and crush it to form pre-baked straw powder. The pyrolysis system includes: A rotary kiln, wherein the inlet of the rotary kiln is the pyrolysis inlet, and the outlet of the rotary kiln is the pyrolysis outlet; A high-temperature flue chamber is provided, in which the rotary kiln is rotatably disposed. The flue gas inlet is located at one end of the side wall of the high-temperature flue chamber near the outlet of the rotary kiln, so as to provide heat to the rotary kiln. The exhaust duct includes a waste heat inlet and a waste heat outlet. The waste heat inlet is located on the side wall of the high-temperature flue gas chamber near the rotary kiln inlet and is connected to the high-temperature flue gas chamber. The waste heat outlet is located on the side wall of the pretreatment channel near the straw outlet and is connected to the pretreatment channel, so as to discharge the flue gas with waste heat in the pyrolysis system to the pretreatment channel for baking the bundled straw. The straw pyrolysis tar recycling carbonization device also includes a combustion system connected to the non-condensable gas outlet. The combustion system includes a combustion device and a heat transfer pipe connected to the combustion device. The non-condensable gas is burned at the combustion device to generate high-temperature flue gas. The heat transfer pipe includes a first branch connected to the flue gas inlet, which can introduce flue gas into the pyrolysis system to provide heat for the pyrolysis of the pre-baked straw-tar mixture. The heat transfer pipe also includes a second branch, which provides heat to the biochar layer.

2. The straw pyrolysis tar recycling and carbonization device according to claim 1, characterized in that: The gas-liquid separation system includes a condensation device and a gas-liquid separation chamber. The condensation device is used to absorb heat within the gas-liquid separation chamber. A pyrolysis gas inlet is provided on one side of the gas-liquid separation chamber, and a non-condensable gas outlet, a light liquid outlet, and a heavy liquid outlet are provided on the other side of the gas-liquid separation chamber. The non-condensable gas outlet, the light liquid outlet, and the heavy liquid outlet are arranged sequentially from top to bottom on the side wall of the gas-liquid separation chamber. The pyrolysis gas inlet is connected to the pyrolysis gas outlet, and the heavy liquid outlet is used for the tar to flow out. The heavy liquid outlet is connected to the pumping system to transport the tar.

3. The straw pyrolysis tar recycling and carbonization device according to claim 2, characterized in that: It also includes a conveying mechanism, which comprises: A connecting channel is provided, with its inlet end sealed to the straw outlet and its outlet end sealed to the pyrolysis inlet; the connecting channel is used to convey the pre-baked straw powder. A feeder is installed at the pyrolysis inlet to feed the pre-baked straw powder into the pyrolysis system. A spraying mechanism is installed at the end of the pumping system. The output end of the spraying mechanism faces the surface of the feeder to spray the tar onto the pre-baked straw powder. A drive unit, connected to the fabric spreader, is used to drive the fabric spreader.

4. The straw pyrolysis tar recycling and carbonization device according to claim 2, characterized in that: The pretreatment system is a pusher plate furnace, the straw inlet is the inlet of the pusher plate furnace, and the straw outlet is the outlet of the pusher plate furnace; The pretreatment system also includes a flue gas outlet and an induced draft fan. The flue gas outlet is located at one end of the inlet of the pusher furnace, and the induced draft fan is located at the flue gas outlet to guide the flue gas with residual heat in the pusher furnace to be discharged through the flue gas outlet.

5. The straw pyrolysis tar recycling and carbonization device according to claim 2, characterized in that: The blade assembly includes: A rotating shaft is rotatably mounted on the side wall of the pretreatment channel; A blade assembly, detachably connected to the rotating shaft; and A motor, connected to the rotating shaft, is used to drive the rotating shaft to rotate, so that the scissor assembly can break and crush the bundled straw.

6. A method for increasing carbonization of straw pyrolysis tar using the straw pyrolysis tar recycling carbonization device according to any one of claims 1 to 5, characterized in that, include: The straw is baked using the pretreatment system. The pre-baked straw is received through the pyrolysis system to pyrolyze the pre-baked straw and generate the biochar; The waste heat from the pyrolysis system is discharged to the pretreatment channel to provide heat for baking the straw. The tar is separated by the separation system and pumped to the pyrolysis inlet, and then sprayed onto the pre-baked straw to allow the tar to be pyrolyzed again.

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