Fluidized bed pyrolysis experiment table and experiment method

Abstract

The invention discloses a fluidized bed pyrolysis experiment table and an experiment method.The experiment table comprises a feeding tank, a spiral feeder, a fluidized bed reactor, an electric heating furnace, a fluidizing atmosphere input pipeline, a thermocouple, a coke collector, a pyrolysis liquid collector, a cooler and an electric precipitator; a discharge hole of the spiral feeder is communicated with the bottom of the fluidized bed reactor; the fluidized bed reactor is arranged in the electric heating furnace; one end of the fluidizing atmosphere input pipeline is communicated with the bottom of the fluidized bed reactor; an airflow control valve is mounted on the fluidizing atmosphere input pipeline; the thermocouple is mounted at the top of the fluidized bed reactor and extends into the fluidized bed reactor; the fluidized bed reactor, the coke collector, the pyrolysis liquid collector and the electric dust remover are sequentially connected and communicated through pipelines; and the pyrolysis liquid collector is arranged in the cooler. According to the invention, the miniaturization of the operation scale of the fluidized bed, the controllability and quantification of experimental conditions and the precision of experimental data acquisition are realized.

Description

Technical Field

[0001] The invention relates to the technical field of fluidized bed experiments, and more particularly to a fluidized bed pyrolysis experimental platform and an experimental method. Background Art

[0002] The biomass pyrolysis and gasification fluidized bed experimental device can simulate the pyrolysis and gasification process of biomass in a fluidized bed and produce corresponding solid, liquid and gas three-phase products.

[0003] However, the existing fluidized bed pyrolysis experimental equipment has the following problems: 1) It is large in scale, complex in operation, and runs in a rough manner. It cannot be operated by one person, and it is difficult to achieve accurate and quantitative material input and reaction condition control. The experimental results have large fluctuations and uncertainties, which seriously affect the scientific nature and reliability of the experiment and are not suitable for laboratory experiments; 2) It is large and bulky, inconvenient to install and maintain, and has high operating and maintenance costs. It is not suitable for laboratory environments with high requirements for spatial layout and adjustment of equipment operating parameters; 3) It is prone to operational failures such as poor sealing (air leakage), material loss (insufficient fluidization), and blockage, which is not ideal for experimental equipment that requires precise results.

[0004] Therefore, providing an efficient, flexible, accurate and low-cost fluidized bed pyrolysis test bench and experimental method is an urgent problem to be solved by technicians in this field. Summary of the invention

[0005] In view of this, the present invention provides a fluidized bed pyrolysis experimental platform and an experimental method to solve the problems of expensive cost, poor stability and reproducibility of experimental results, and slow experimental cycle of existing fluidized bed pyrolysis experimental devices.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A fluidized bed pyrolysis test bench comprises a feed tank, a screw feeder, a fluidized bed reactor, an electric heating furnace, a fluidized atmosphere input pipeline, a thermocouple, a coke collector, a pyrolysis liquid collector, a cooler and an electrostatic precipitator, wherein the feed tank is connected and communicated with the feed inlet of the screw feeder, the discharge outlet of the screw feeder is connected and communicated with the bottom of the fluidized bed reactor, the fluidized bed reactor is installed in the electric heating furnace and both ends of the fluidized bed reactor extend out of the electric heating furnace; one end of the fluidized atmosphere input pipeline is connected and communicated with the bottom of the fluidized bed reactor, and an airflow control valve is installed on the fluidized atmosphere input pipeline; the thermocouple is installed on the top of the fluidized bed reactor and extends into the interior thereof; the fluidized bed reactor, the coke collector, the pyrolysis liquid collector and the electrostatic precipitator are connected and communicated with each other through pipelines in sequence; the pyrolysis liquid collector is installed in the cooler.

[0008] Furthermore, the fluidized bed reactor and the pipeline, the coke collector and the pipeline, the pyrolysis liquid collector and the pipeline, and the electrostatic precipitator and the pipeline are all detachably connected.

[0009] Furthermore, the screw feeder includes a shell, a screw rod and a servo motor, the feed tank is connected to the feed port on the shell, and the discharge port on the shell is connected to the bottom of the fluidized bed reactor; the screw rod is installed inside the shell; the servo motor is installed at one end of the shell and fixedly connected to one end of the screw rod.

[0010] Furthermore, the feed tank includes a tank body and a cover body, the bottom of the tank body is connected to the feed inlet; and the cover body is threadedly connected to the top of the tank body.

[0011] Furthermore, a first quartz sand filter plate is installed near the bottom of the fluidized bed reactor.

[0012] Furthermore, a second quartz sand filter plate is installed near the outlet end of the coke collector.

[0013] Furthermore, it also includes a support frame, and the screw feeder, the electric heating furnace, the cooler and the electric precipitator are all installed on the support frame; a universal wheel is installed at the bottom of the support frame.

[0014] The experimental method performed using a fluidized bed pyrolysis test bench as described above comprises the following steps:

[0015] 1) Weigh all disassembled parts, including the fluidized bed reactor, coke collector, cooler, electrostatic precipitator and various pipelines;

[0016] 2) Weigh 20g of washed and dried quartz sand and add it to the fluidized bed reactor; then add 20g-100g of biomass raw material to the feed tank, then cover it with a lid and tighten it to seal;

[0017] 3) Wrap the exposed parts of the top and bottom of the fluidized bed reactor and the surrounding of the coke collector with asbestos; turn on the electric heating furnace, set the furnace temperature to 600°C, wait for 30 minutes to preheat the fluidized bed reactor, and then use a thermocouple to measure the furnace temperature of the fluidized bed reactor until the reaction temperature in the fluidized bed reactor stabilizes to the experimental required temperature;

[0018] 4) Opening the air flow control valve to allow the fluidizing carrier gas to flow into the fluidized bed reactor through the fluidizing atmosphere input pipe; turning on the servo motor to adjust the feed rate so that the biomass raw material enters the fluidized bed reactor through the screw feeder; turning on the electrostatic precipitator;

[0019] 5) Thermal cracking occurs: the cracking gas is passed from the coke collector into the pyrolysis liquid collector immersed in the cooler, the pyrolysis gas is cooled, the liquid phase is cooled and collected, the gas phase is passed into the electrostatic precipitator for secondary collection, and the tail gas that cannot be collected is discharged; the thermal cracking process lasts for 100-120 minutes, when there is no visible tail gas discharged from the tail gas outlet of the electrostatic precipitator, the experiment is stopped, and the power supply of the electric heating furnace and the electrostatic precipitator is turned off;

[0020] 6) Remove the asbestos covering the fluidized bed reactor and the coke collector. When the temperature in the fluidized bed reactor drops below 350°C, open the door of the electric heating furnace;

[0021] 7) When the temperature drops to near room temperature, all disassembled parts are disassembled and weighed respectively. According to the mass of each disassembled part before and after the reaction, the yield of solid phase, liquid phase and gas phase products, as well as the cooling efficiency of the cooler can be obtained by subtraction method;

[0022] 8) Collecting the bio-oil and char obtained by pyrolysis to determine the composition;

[0023] 9) After the experiment, all disassembled parts were cleaned for next use; the cooler was cleaned with isopropyl alcohol and then blown dry; the fluidized bed reactor, coke collector and various pipelines were placed in a muffle furnace, heated at 600°C for 4 hours, and then taken out and blown with air to remove the remaining ash.

[0024] It can be seen that the present invention provides a fluidized bed pyrolysis test bench and an experimental method. Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The material feed rate, carrier gas flow rate, reaction temperature in the bed, and pyrolysis liquid cooling and collection temperature can all be precisely controlled, that is, each experimental parameter can be precisely adjusted, so that the data obtained from the experiment is extremely accurate, avoiding the large deviation between the experimental results and the ideal state caused by the accumulated errors due to the large size of the equipment and the low accuracy of the data acquisition instrument when using conventional fluidized beds for experiments, thus failing to achieve the research purpose of the experiment;

[0026] 2) Only a small amount of material is needed to realize the fluidized bed pyrolysis reaction of the material, that is, very little material is used, the equipment is miniaturized, detachable and easy to clean, which is extremely practical and convenient for experimental research. It not only gets rid of the trouble of insufficient experimental materials, but also gets rid of the problems of conventional fluidized bed experiments such as high cost of running an experiment, too complicated operation, and difficulty in cleaning the equipment after the experiment, which affects the accuracy of the next experimental results;

[0027] 3) The equipment is compact and the entire laboratory table only requires 3-5m2 of floor space 2The height does not exceed 2m, and the laboratory environment requirements are not high. Conventional indoor laboratories equipped with water, electricity and fume hoods can meet its operating requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0029] Figure 1 The accompanying drawing is a flow chart of a fluidized bed pyrolysis test bench provided by the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0031] like Figure 1As shown, the embodiment of the present invention discloses a fluidized bed pyrolysis test bench, which is used for accurate quantitative fluidized bed pyrolysis experiments of trace biomass and other organic materials with a total feed amount of 20g < 100g under ordinary laboratory conditions under the condition that various parameters such as feed rate, fluidization rate, and fluidization temperature are accurately controllable, including a feed tank 1, a screw feeder 2, a fluidized bed reactor 3, an electric heating furnace 4, a fluidized atmosphere input pipeline 5, a thermocouple 6, a coke collector 7, a pyrolysis liquid collector 8, a cooler 9 and an electrostatic precipitator 10. The feed tank 1 is connected to the feed inlet of the screw feeder 2, and the discharge port of the screw feeder 2 is connected to the bottom of the fluidized bed reactor 3. The fluidized bed reactor 3 is installed in the electric heating furnace 4 and the fluidized atmosphere is input into the fluidized bed reactor 3. Electric heating furnace 4 extends from both ends of the bed reactor 3. In this embodiment, the main body of the fluidized bed reactor 3 is a high-temperature resistant metal pipe with an inner diameter of 2-3 cm and a length of 40-50 cm; one end of the fluidized atmosphere input pipeline 5 is connected to the bottom of the fluidized bed reactor 3, and an airflow control valve 11 is installed on the fluidized atmosphere input pipeline 5; a thermocouple 6 is installed on the top of the fluidized bed reactor 3 and extends into the interior thereof; the fluidized bed reactor 3, the coke collector 7, the pyrolysis liquid collector 8 and the electrostatic precipitator 10 are connected and communicated in sequence through pipelines. In this embodiment, the main body of the coke collector 7 is a metal can with hemispherical ends and a cylindrical middle section, a length of 10-20 cm and a diameter of 5-10 cm; the pyrolysis liquid collector 8 is installed in the cooler 9. The present invention realizes the miniaturization of the fluidized bed operation scale, the controllability and quantification of the experimental conditions, and the precision of the experimental data acquisition.

[0032] Specifically, the fluidized bed reactor 3 and the pipeline, the coke collector 7 and the pipeline, the pyrolysis liquid collector 8 and the pipeline, and the electrostatic precipitator 10 and the pipeline are all detachably connected.

[0033] Specifically, the screw feeder 2 includes a shell, a screw rod and a servo motor 21. The feed tank 1 is connected to the inlet on the shell, and the outlet on the shell is connected to the bottom of the fluidized bed reactor 3; the screw rod is installed inside the shell; the servo motor 21 is installed at one end of the shell and fixedly connected to one end of the screw rod.

[0034] Specifically, the feed tank 1 includes a tank body and a cover body, the bottom of the tank body is connected to the feed port; the cover body is threadedly connected to the top of the tank body, and the cover body is tightened and sealed after the material is put into the tank body to prevent the carrier gas from blowing back during operation.

[0035] In order to further optimize the technical solution of the present invention, the fluidized bed reactor 3 is installed with a first quartz sand filter plate near the bottom of the bed, which is made of high temperature resistant material to ensure that the carrier gas flows evenly at the bottom of the bed and there is no leakage of materials.

[0036] In order to further optimize the technical solution of the present invention, a second quartz sand filter plate is installed near the outlet end of the coke collector 7 .

[0037] Specifically, it also includes a support frame, on which the screw feeder 2, the electric heating furnace 4, the cooler 9 and the electric precipitator 10 are all installed, and the support frame occupies an area of ​​about 2-3m 2 ; Universal wheels are installed at the bottom of the support frame, which can be moved at will.

[0038] The embodiment of the present invention also discloses an experimental method using the fluidized bed pyrolysis experimental platform as described above, comprising the following steps:

[0039] 1) Weighing all disassembled parts, including the fluidized bed reactor 3, the coke collector 7, the cooler 9, the electrostatic precipitator 10 and various pipelines;

[0040] 2) Weigh 20 g of washed and dried quartz sand and add it to the fluidized bed reactor 3; then add 20 g to 100 g of biomass raw material into the feed tank 1, and then cover it with a lid and tighten it to seal;

[0041] 3) Wrap the exposed parts of the top and bottom of the fluidized bed reactor 3 and the surrounding of the coke collector 7 with asbestos; turn on the electric heating furnace 4, set the furnace temperature to 600° C., wait for 30 minutes to preheat the fluidized bed reactor 3, and then use the thermocouple 6 to measure the furnace temperature of the fluidized bed reactor 3 until the reaction temperature in the fluidized bed reactor 3 stabilizes to the experimental required temperature. The electric heating furnace 4 and the thermocouple 6 are used in conjunction with each other to achieve precise control of the fluidized bed reaction temperature;

[0042] 4) Open the air flow control valve 11 to allow the fluidized carrier gas (usually an inert atmosphere, such as N2) to flow into the fluidized bed reactor 3 through the fluidized atmosphere input pipe 5. The use of the air flow control valve 11 can achieve precise control of the fluidized air flow velocity; turn on the servo motor 21 to allow the biomass raw material to enter the fluidized bed reactor 3 through the screw feeder 2. In this embodiment, the feeding speed is 0.5g-2g / min. The servo motor 21 controls the rotation rate of the screw rod to achieve precise quantitative feeding, and controls the progress of the entire fluidized bed reaction from the material end; turn on the electrostatic precipitator 10;

[0043] 5) Thermal cracking occurs: the cracking gas is passed from the coke collector 7 into the pyrolysis liquid collector 8 immersed in the cooler 9, the pyrolysis gas is cooled, the liquid phase is cooled and collected, and the gas phase is passed into the electrostatic precipitator 10 for secondary collection, and the tail gas that cannot be collected is discharged. The tail gas can be connected to the flue gas measuring instrument to measure the relevant gas components, and then discharged through the fume hood; the thermal cracking process lasts for 100-120 minutes. When there is no visible tail gas discharged from the tail gas outlet of the electrostatic precipitator 10, the experiment is stopped, and the power supply of the electric heating furnace 4 and the electrostatic precipitator 10 is turned off;

[0044] 6) Remove the asbestos covering the fluidized bed reactor 3 and the coke collector 7. When the temperature in the fluidized bed reactor 3 drops below 350° C., open the door of the electric heating furnace 4;

[0045] 7) When the temperature drops to near room temperature, all disassembled parts are disassembled and weighed separately. According to the mass of each disassembled part before and after the reaction, the yield of solid phase (charcoal), liquid phase (bio-oil), gas phase (non-liquefiable tail gas), and cooling efficiency of the cooler can be obtained by subtraction.

[0046] 8) Collecting the bio-oil and char obtained by pyrolysis to determine the composition;

[0047] 9) After the experiment, all disassembled parts are cleaned for next use; the cooler 9 is cleaned with isopropyl alcohol and then blown dry; the fluidized bed reactor 3, the coke collector 7 and each pipeline are placed in a muffle furnace, heated at 600°C for 4 hours, and then taken out and blown with air to remove the residual ash.

[0048] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0049] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluidized bed pyrolysis test bench, characterized in that: It includes a feed tank, a screw feeder, a fluidized bed reactor, an electric heating furnace, a fluidized atmosphere input pipeline, a thermocouple, a coke collector, a pyrolysis liquid collector, a cooler and an electrostatic precipitator. The feed tank is connected to the feed inlet of the screw feeder, the discharge port of the screw feeder is connected to the bottom of the fluidized bed reactor, the fluidized bed reactor is installed in the electric heating furnace and both ends of the fluidized bed reactor extend out of the electric heating furnace; one end of the fluidized atmosphere input pipeline is connected to the bottom of the fluidized bed reactor, and an airflow control valve is installed on the fluidized atmosphere input pipeline; the thermocouple is installed on the top of the fluidized bed reactor and extends into the interior thereof; the fluidized bed reactor, the coke collector, the pyrolysis liquid collector and the electrostatic precipitator are connected to each other through pipelines in sequence; the pyrolysis liquid collector is installed in the cooler.

2. A fluidized bed pyrolysis test bench according to claim 1, characterized in that: The fluidized bed reactor and the pipeline, the coke collector and the pipeline, the pyrolysis liquid collector and the pipeline, and the electrostatic precipitator and the pipeline are all detachably connected.

3. A fluidized bed pyrolysis test bench according to claim 1 or 2, characterized in that: The screw feeder includes a shell, a screw rod and a servo motor. The feed tank is connected to the feed inlet on the shell, and the discharge port on the shell is connected to the bottom of the fluidized bed reactor. The screw rod is installed inside the shell. The servo motor is installed at one end of the shell and fixedly connected to one end of the screw rod.

4. A fluidized bed pyrolysis test bench according to claim 3, characterized in that: The feed tank comprises a tank body and a cover body, the bottom of the tank body is connected and communicated with the feed inlet; the cover body is threadedly connected with the top of the tank body.

5. The fluidized bed pyrolysis test bench according to claim 1, characterized in that: The fluidized bed reactor is provided with a first quartz sand filter plate near the bed bottom.

6. A fluidized bed pyrolysis test bench according to claim 1 or 5, characterized in that: The coke collector is provided with a second quartz sand filter plate near the outlet end.

7. The fluidized bed pyrolysis test bench according to claim 1, characterized in that: It also includes a support frame, on which the screw feeder, the electric heating furnace, the cooler and the electric precipitator are all installed; and a universal wheel is installed at the bottom of the support frame.

8. An experimental method using a fluidized bed pyrolysis test bench as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: 1) Weigh all disassembled parts, including the fluidized bed reactor, coke collector, cooler, electrostatic precipitator and various pipelines; 2) Weigh 20g of washed and dried quartz sand and add it to the fluidized bed reactor; then add 20g-100g of biomass raw material to the feed tank, then cover it with a lid and tighten it to seal; 3) Wrap the exposed parts of the top and bottom of the fluidized bed reactor and the surrounding of the coke collector with asbestos; turn on the electric heating furnace, set the furnace temperature to 600°C, wait for 30 minutes to preheat the fluidized bed reactor, and then use a thermocouple to measure the furnace temperature of the fluidized bed reactor until the reaction temperature in the fluidized bed reactor stabilizes to the experimental required temperature; 4) Opening the air flow control valve to allow the fluidizing carrier gas to flow into the fluidized bed reactor through the fluidizing atmosphere input pipe; turning on the servo motor to allow the biomass raw material to enter the fluidized bed reactor through the screw feeder; Turn on the electric dust collector; 5) Thermal cracking occurs: the cracking gas is passed from the coke collector into the pyrolysis liquid collector immersed in the cooler, the pyrolysis gas is cooled, the liquid phase is cooled and collected, the gas phase is passed into the electrostatic precipitator for secondary collection, and the tail gas that cannot be collected is discharged; the thermal cracking process lasts for 100-120 minutes, when there is no visible tail gas discharged from the tail gas outlet of the electrostatic precipitator, the experiment is stopped, and the power supply of the electric heating furnace and the electrostatic precipitator is turned off; 6) Remove the asbestos covering the fluidized bed reactor and the coke collector. When the temperature in the fluidized bed reactor drops below 350°C, open the door of the electric heating furnace; 7) When the temperature drops to near room temperature, all disassembled parts are disassembled and weighed separately. According to the mass of each disassembled part before and after the reaction, the yield of solid phase, liquid phase and gas phase, as well as the cooling efficiency of the cooler can be obtained by subtraction. 8) Collecting the bio-oil and char obtained by pyrolysis to determine the composition; 9) After the experiment, all disassembled parts were cleaned for next use; the cooler was cleaned with isopropyl alcohol and then blown dry; the fluidized bed reactor, coke collector and various pipelines were placed in a muffle furnace, heated at 600°C for 4 hours, and then taken out and blown with air to remove the remaining ash.

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