A small experimental pyrolysis device for rapid production of biochar

Abstract

This invention provides a small-scale experimental pyrolysis device for rapid biochar preparation, comprising a pyrolysis unit, a sample injector, a heating unit, and a ventilation unit. The pyrolysis unit consists of a sample injector tube, a pyrolysis tube, and a condenser tube, which are detachably connected from top to bottom. These tubes are interconnected to form a vertical cavity. Gas is introduced through the sample injector to create an oxygen-free environment within the vertical cavity. The condenser tube condenses and collects the oil and gas generated during pyrolysis and discharges it externally. The inner cavity of the section of the pyrolysis tube heated by the heating unit serves as the pyrolysis zone. The sample injector, independent of the pyrolysis unit, is detachably inserted into the vertical cavity from top to bottom, suspending the loaded biomass sample within the pyrolysis zone. The position of the biomass sample within the vertical cavity is adjustable via the sample injector. The ventilation unit introduces gas into the sample injector through a gas cylinder and collects the oil and gas through a liquid-sealed bottle. This invention effectively improves upon existing rapid pyrolysis devices in laboratories, addressing issues such as biomass adhesion to the walls, incomplete pyrolysis, impure products, and inaccurate yield calculations.

Description

Technical Field

[0001] This utility model relates to a biochar preparation device, and more specifically, a small-scale experimental pyrolysis device for rapid biochar preparation. Background Technology

[0002] Rapid biomass pyrolysis is a process in which biomass is rapidly heated to a preset temperature in an oxygen-deficient environment, causing the biomass to pyrolyze in a short time.

[0003] Biochar is a product of the rapid pyrolysis of biomass. It is defined as a fine-particle, porous solid material remaining after some of the oil and gas in biomass has burned and volatilized during high-temperature processing under oxygen-deficient conditions. Biochar is rich in carbon and hydrogen, with a carbon content typically exceeding 70%. Due to its applications in soil improvement, climate change mitigation, and new energy materials, biochar is also known as "black gold."

[0004] Currently, the main production equipment for biochar is large-scale pyrolysis equipment, commonly used for large-scale, high-volume biochar production. However, due to high production costs and the ease with which different production batches can become mixed, it is not suitable for small-scale, small-batch biochar production in laboratories, nor can it meet the requirements for pyrolysis of specific types of biomass in laboratories. Furthermore, commonly used laboratory rapid pyrolysis devices mainly consist of a sample injector, pyrolysis tube, and condenser. In this type of device, the sample is introduced into the pyrolysis tube by gravity through the piston of the sample injector. This often results in a significant amount of sample adhering to the top of the pyrolysis tube, preventing complete pyrolysis of the biomass. Consequently, unpyrolyzed sample may be mixed into the biochar during sampling, affecting the properties of the biochar and test results. Additionally, not all the sample in the sample injector can be added to the pyrolysis tube, affecting the calculation of biochar yield. Moreover, traditional pyrolysis devices require disassembly and cleaning of the sample injector and pyrolysis tube after pyrolysis, significantly increasing the workload. Utility Model Content

[0005] To address the problems of biomass adhesion to the walls, incomplete pyrolysis, impure products, and inaccurate yield calculations in existing laboratory rapid pyrolysis devices, this invention proposes a small-scale experimental pyrolysis device for rapid biochar preparation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A small-scale experimental pyrolysis device for rapid biochar preparation, characterized by the following structural features:

[0008] Includes pyrolysis apparatus, sample injector, heating apparatus and ventilation apparatus;

[0009] The pyrolysis device consists of a sample inlet tube, a pyrolysis tube, and a condenser tube, which are detachably connected from top to bottom. The tubes are interconnected to form a vertical cavity with an open top and a closed bottom. Gas is introduced through the sample inlet tube to create an oxygen-free environment in the vertical cavity. The oil and gas generated during pyrolysis are condensed and collected by the condenser tube and discharged externally. The inner cavity of the section of the pyrolysis tube heated by the heating device is used as the pyrolysis zone. The sample injector is independent of the pyrolysis device and is detachably inserted into the vertical cavity from top to bottom. The loaded biomass sample is suspended in the pyrolysis zone. The top opening of the vertical cavity is detachably sealed by the attached seal. The position of the biomass sample in the vertical cavity is adjustable by the sample injector.

[0010] The ventilation device introduces air into the sample inlet tube through a gas cylinder via an air inlet pipe, and collects the oil and gas discharged from the condenser tube through a liquid seal bottle;

[0011] The heating device is used to heat the pyrolysis zone of the pyrolysis tube.

[0012] The structural features of this utility model also lie in:

[0013] The sample injector includes a boom, a sample tube, a rubber stopper, and a cable tie. The sample tube is an open tube at the top, used to load biomass samples, and is fixedly suspended at the lower part of the boom. The rubber stopper is a frustum-shaped structure that is larger at the top and smaller at the bottom, and is movably inserted through the boom by external force. The sample injector is inserted into the vertical cavity of the pyrolysis device through the boom, suspending the sample tube containing the biomass samples in the pyrolysis zone. The rubber stopper is used as a sealing element and is inserted to seal the top opening of the vertical cavity. The cable tie on the boom is used to tighten the upper end of the rubber stopper to fix its current position.

[0014] The pyrolysis tube, which serves as the pyrolysis zone, is located at the bottom of the tube body.

[0015] The heating device is a vertical open-type tubular furnace, equipped with thermocouples for detecting the temperature of the pyrolysis zone.

[0016] The detection end of the thermocouple is located vertically in the middle of the core of the vertical open tubular furnace.

[0017] In the ventilation device: the outlet of the gas cylinder is directly connected to the inlet pipe of the sample inlet tube through the inlet rubber tube, and gas is continuously introduced to form an oxygen-free environment in the vertical cavity. The liquid-sealed bottle is filled with 3 / 4 volume of water. The outlet pipe of the condenser tube is connected to the outlet rubber tube, and the free end of the outlet rubber tube is inserted into the liquid-sealed bottle and submerged in the water inside the bottle.

[0018] The lower part of the condenser tube is immersed in ice-cold ethanol contained in a thermos cup, and the tube body exposed above the thermos cup is provided with an exhaust pipe for venting oil and gas.

[0019] Compared with existing technologies, the beneficial effects of this utility model are reflected in:

[0020] 1. The sample injector and the pyrolysis device are independent of each other. The sample injector is used to load the biomass sample, and the position of the biomass sample in the vertical cavity is adjustable through the sample injector. Before the pyrolysis zone is heated to the preset temperature by the heating device, the biomass sample can be removed from the pyrolysis zone without affecting the oxygen-free environment in the vertical cavity, thus avoiding the simultaneous heating of biomass. After the pyrolysis zone stabilizes at the preset temperature, the entire biomass sample can be quickly extended into the pyrolysis zone for full pyrolysis.

[0021] 2. The sample injector and the pyrolysis device are independent of each other. After pyrolysis is completed, the sample injector can be removed and the biochar can be taken out directly from the sample injector. This allows for accurate calculation of biochar yield and eliminates the possibility of residual substances in the pyrolysis tube.

[0022] 3. The injector and pyrolysis device are independent of each other. After pyrolysis is completed, only the injector needs to be removed for cleaning. There is no need to disassemble other components, which simplifies the experimental operation, reduces the difficulty, and improves efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] Figure 2 This is a schematic diagram of the sample inlet tube;

[0025] Figure 3 This is a schematic diagram of the pyrolysis tube structure;

[0026] Figure 4 This is a schematic diagram of the condenser tube structure;

[0027] Figure 5 This is a schematic diagram of the injector.

[0028] In the picture:

[0029] 11 Sample inlet tube; 111 Gas inlet tube; 12 Pyrolysis tube; 121 Bell mouth; 13 Condenser tube; 131 Conical section; 132 Gas outlet tube; 14 Thermos cup; 141 Ice ethanol;

[0030] 2. Sample injector; 21. Boom; 22. Sample carrier tube; 23. Rubber stopper; 24. Cable tie; 25. Biomass sample;

[0031] 3. Heating device; 31. Thermocouple; 32. Resistance furnace temperature controller;

[0032] 41 Gas cylinder; 42 Inlet rubber hose; 43 Liquid seal bottle; 431 Water; 44 Outlet rubber hose. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0034] Please refer to Figure 1 The small-scale experimental pyrolysis device for rapid preparation of biochar in this embodiment includes a pyrolysis device, a sample injector 2, a heating device 3, and a ventilation device.

[0035] like Figures 2 to 4 The pyrolysis device consists of a sample inlet tube 11, a pyrolysis tube 12, and a condenser tube 13, which are detachably connected from top to bottom. The tubes are interconnected to form a vertical cavity with an open top and a closed bottom. Gas is introduced through the sample inlet tube 11 to create an oxygen-free environment in the vertical cavity. The oil and gas generated during pyrolysis are condensed and collected by the condenser tube 13 and discharged externally. The inner cavity of the section of the pyrolysis tube 12 heated by the heating device 3 is used as the pyrolysis zone. The sample injector 2 is independent of the pyrolysis device and is detachably inserted into the vertical cavity from top to bottom. The loaded biomass sample 25 is suspended in the pyrolysis zone. The top opening of the vertical cavity is detachably sealed by the sealing element. The position of the biomass sample 25 in the vertical cavity is adjustable by the sample injector 2.

[0036] The ventilation device introduces air into the sample inlet tube 11 through the air inlet pipe 111 via the gas cylinder 41, and collects the oil and gas discharged from the condenser tube 13 through the liquid seal bottle 43.

[0037] Heating device 3 is used to heat the pyrolysis zone of pyrolysis tube 12.

[0038] The structural features of this utility model also lie in:

[0039] like Figure 5 As shown, the sample injector 2 includes a boom 21, a sample carrier tube 22, a rubber stopper 23, and a cable tie 24. The sample carrier tube 22 is a tube with an open top, used to load the biomass sample 25, and is fixedly suspended at the lower part of the boom 21. The rubber stopper 23 is a frustum-shaped structure that is larger at the top and smaller at the bottom, and is movably inserted along the boom 21 by external force. The sample injector 2 is inserted into the vertical cavity of the pyrolysis device through the boom 21, suspending the sample carrier tube 22 containing the biomass sample 25 in the pyrolysis zone. The rubber stopper 23 is used as a sealing element to seal the top opening of the vertical cavity. The cable tie 24 tied to the boom 21 is used to tighten the upper end of the rubber stopper 23, thus fixing the current position of the rubber stopper 23. The gap between the rubber stopper 23 and the inlet of the sample carrier tube 11 can be further sealed with a sealing tape.

[0040] The boom 21 is a metal steel boom.

[0041] The pyrolysis tube 12, which serves as the pyrolysis zone, is located at the bottom of the tube body. The section of the tube above the pyrolysis zone is not heated by the heating device 3, thus preventing the biomass loaded in the injector 2 from being heated simultaneously when the heating device 3 heats the pyrolysis zone but has not reached the preset temperature. The injection tube 11 should be able to accommodate the complete insertion of the sample carrier tube 22.

[0042] The two ends of the pyrolysis tube 12 are respectively formed into flared mouths 121 with the larger end facing outward. The flared mouths 121 are connected to the sample inlet tube 11 and the condenser tube 13. The ends of the sample inlet tube 11 and the condenser tube 13 used to connect with the pyrolysis tube 12 are respectively formed into conical sections 131 adapted to the flared mouths 121.

[0043] The heating device 3 is a vertical open tube furnace, equipped with a thermocouple 31 for detecting the temperature of the pyrolysis zone, and a resistance furnace temperature controller 32. The thermocouple 31 is connected to the resistance furnace temperature controller 32. The resistance furnace temperature controller 32 is used to set a preset temperature value, receive the real-time temperature value detected by the thermocouple 31 and analyze and compare it with the preset temperature value, and adjust the heating temperature according to the analysis and comparison results.

[0044] The detection end of thermocouple 31 is located vertically in the middle of the core of the vertical open-type tubular furnace, and is also at the same height as the middle of the sample tube 22 during pyrolysis. The pyrolysis device is installed in the vertical open-type tubular furnace, with the sample inlet tube 11 and the upper section of the pyrolysis tube 12 exposed outside the furnace. Only the pyrolysis zone section of the pyrolysis tube 12 is heated by the vertical open-type tubular furnace, and the condenser tube 13 is exposed outside the furnace.

[0045] In the ventilation device: the outlet of the gas cylinder 41 is directly connected to the inlet pipe 111 of the sample inlet tube 11 through the inlet rubber tube 42, continuously introducing inert gases such as N2 or CO2 to create an oxygen-free environment in the vertical cavity and remove the oil and gas produced by biomass. The liquid seal bottle 43 is used to prevent the oil and gas with irritating odor from being directly discharged into the air while preventing the outside air from entering. It can also be used to judge the sealing performance of the device and monitor the gas flow rate. The bottle is filled with 3 / 4 volume of water 431. The outlet pipe 132 of the condenser tube 13 is connected to the outlet rubber tube 44. The free end of the outlet rubber tube 44 is inserted into the liquid seal bottle 43 and submerged in the water 431 in the bottle to prevent the oil and gas produced by biomass pyrolysis from being directly discharged into the outside air.

[0046] Gas cylinder 41 is equipped with a main valve, a pressure reducing valve and a rotor flow meter.

[0047] The lower part of the condenser tube 13 is immersed in ice ethanol 141 contained in the thermos cup 14. The tube body exposed above the thermos cup 14 is provided with an exhaust pipe 132 for venting oil and gas, to prevent the condensed oil and gas from clogging the exhaust rubber tube 44.

[0048] When using this device to conduct pyrolysis experiments on biomass, the following steps can be followed:

[0049] 1.1 Before sample injection, the vertical open-type tube furnace should be in the open position;

[0050] 1.2 After adding biomass sample 25 to sample tube 22, insert sampler 2 downwards from the upper opening of sample tube 11 into the vertical cavity of pyrolysis device, so that rubber stopper 23 is inserted into the upper opening of sample tube 11. Rubber stopper 23 remains stationary, and the lifting rod 21 continues to descend until the middle of sample tube 22 is roughly at the same level as the detection end of thermocouple 31. Tie cable tie 24 tightly to the lifting rod 21 so that it presses against the upper end of rubber stopper 23. The sealing tape can be used to further seal the gap between rubber stopper 23 and upper opening of sample tube 11, and between lifting rod 21 and rubber stopper 23.

[0051] 1.3. Closure of vertical open-type tubular furnace;

[0052] 1.4. Pull up the lifting rod 21 with the cable tie 24 to lift the sample tube 22 until most of the tube body is inside the sample inlet tube 11, leaving a vertical gap between it and the rubber stopper 23. Open the main valve and pressure valve of the gas cylinder 41 in sequence, and adjust the rotor flow meter to adjust the gas flow rate to the set value. During this process, the overall sealing condition and gas flow rate of the device can be judged by the bubbling condition in the liquid seal bottle 43. After ventilating for about 10 minutes, start the resistance furnace temperature controller 32 to start the vertical open tube furnace and heat the pyrolysis zone of the pyrolysis tube 12 to the preset temperature.

[0053] 1.5 When the thermocouple 31 detects that the temperature of the pyrolysis zone is stable at the preset temperature, push down the rod 21 with the cable tie 24 until the cable tie 24 just touches the upper end of the rubber stopper 23 again. At this time, the middle part of the sample tube 22 is again roughly at the same level as the detection end of the thermocouple 31, so that the biomass sample 25 in the sample tube 22 is rapidly pyrolyzed at the preset temperature. After the set time, turn off the resistance furnace temperature controller 32.

[0054] 1.6. Restart the resistance furnace temperature controller 32, but do not heat the pyrolysis zone. It is only used to display the real-time temperature of the pyrolysis zone detected by the thermocouple 31. When the real-time temperature reaches room temperature, the vertical open tube furnace can be restarted to accelerate the cooling of the biomass sample 25. In this step, it should be noted that even if the pyrolysis zone cools to room temperature, the sample injector 2 should not be removed immediately, especially when pyrolysis is carried out at higher temperatures. Instead, the sample injector 2 should be left in the pyrolysis tube 12 for a period of time to prevent the biochar produced by pyrolysis from reigniting due to incomplete cooling and re-exposed to air.

[0055] 1.7 After the biomass sample 25 has completely cooled, close the main valve and pressure divider valve of the gas cylinder 41, take out the sample injector 2, take out the biochar sample after rapid pyrolysis from the sample carrier tube 22, weigh it and calculate the yield.

[0056] 1.8 Clean the injector 2.

[0057]

[0058] The table above shows the biochar quality and yield obtained by rapidly pyrolyzing approximately 5 g of tobacco straw biomass at different preset temperatures.

[0059] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A small-scale experimental pyrolysis apparatus for rapid biochar preparation, characterized in that: Includes pyrolysis apparatus, sample injector, heating apparatus and ventilation apparatus; The pyrolysis device consists of a sample inlet tube, a pyrolysis tube, and a condenser tube, which are detachably connected from top to bottom. The tubes are interconnected to form a vertical cavity with an open top and a closed bottom. Gas is introduced through the sample inlet tube to create an oxygen-free environment in the vertical cavity. The oil and gas generated during pyrolysis are condensed and collected by the condenser tube and discharged externally. The inner cavity of the section of the pyrolysis tube heated by the heating device is used as the pyrolysis zone. The sample injector is independent of the pyrolysis device and is detachably inserted into the vertical cavity from top to bottom. The loaded biomass sample is suspended in the pyrolysis zone. The top opening of the vertical cavity is detachably sealed by the attached seal. The position of the biomass sample in the vertical cavity is adjustable by the sample injector. The ventilation device introduces air into the sample inlet tube through a gas cylinder via an air inlet pipe, and collects the oil and gas discharged from the condenser tube through a liquid seal bottle; The heating device is used to heat the pyrolysis zone of the pyrolysis tube.

2. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 1, characterized in that: The sample injector includes a boom, a sample tube, a rubber stopper, and a cable tie. The sample tube is an open tube at the top, used to load biomass samples, and is fixedly suspended at the lower part of the boom. The rubber stopper is a frustum-shaped structure that is larger at the top and smaller at the bottom, and is movably inserted through the boom by external force. The sample injector is inserted into the vertical cavity of the pyrolysis device through the boom, suspending the sample tube containing the biomass samples in the pyrolysis zone. The rubber stopper is used as a sealing element and is inserted to seal the top opening of the vertical cavity. The cable tie on the boom is used to tighten the upper end of the rubber stopper to fix its current position.

3. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 1, characterized in that: The pyrolysis tube, which serves as the pyrolysis zone, is located at the bottom of the tube body.

4. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 1, characterized in that: The heating device is a vertical open-type tubular furnace, equipped with thermocouples for detecting the temperature of the pyrolysis zone.

5. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 4, characterized in that: The detection end of the thermocouple is located vertically in the middle of the core of the vertical open tubular furnace.

6. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 1, characterized in that, In the ventilation device: the outlet of the gas cylinder is directly connected to the inlet pipe of the sample inlet tube through the inlet rubber tube, and gas is continuously introduced to form an oxygen-free environment in the vertical cavity. The liquid-sealed bottle is filled with 3 / 4 volume of water. The outlet pipe of the condenser tube is connected to the outlet rubber tube, and the free end of the outlet rubber tube is inserted into the liquid-sealed bottle and submerged in the water inside the bottle.

7. The small-scale experimental pyrolysis apparatus for rapid biochar preparation according to claim 1 or 6, characterized in that: The lower part of the condenser tube is immersed in ice-cold ethanol contained in a thermos cup, and the tube body exposed above the thermos cup is provided with an exhaust pipe for venting oil and gas.

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