Downer reactor gas-solid reaction kinetics test system and method

Abstract

The invention discloses a downer reactor gas-solid reaction kinetics testing system and method, and belongs to the technical field of gas-solid reaction kinetics measurement. The system comprises a preheating device, an input pipe, a material collecting bin, a downer gas-solid reaction furnace, a power compensation heat preservation sleeve, an output pipe, a gas concentration sensor, a feeding device and an induced draft fan. The preheating device is connected with an input port of the input pipe; an output port of the input pipe is connected with the lower part of the downer gas-solid reaction furnace; the material collecting bin is arranged at the lower end of the downer gas-solid reaction furnace; the downer gas-solid reaction furnace is sleeved with the power compensation heat preservation sleeve; an input port of the output pipe is connected with the upper end of the downer gas-solid reaction furnace; the feeding device is communicated with the outer wall, close to the input port, of the output pipe; the gas concentration sensor is inserted into the output pipe; and an output port of the output pipe is communicated with the induced draft fan. The test system provided by the invention can accurately control reaction conditions and data acquisition, and can perform comprehensive kinetic analysis on complex gas-solid reactions.

Description

Technical Field

[0001] This application relates to the technical field of gas-solid reaction kinetics measurement, and particularly to a gas-solid reaction kinetics test system and method for a downer reactor. Background Art

[0002] In industries such as chemical engineering and energy, gas-solid reaction processes are widespread and crucial. Gas-solid reactions are involved in multiple industries, including but not limited to coal chemical industry, petrochemical industry, metallurgy, environmental protection, etc. For example, in the coal chemical industry, the gasification and combustion processes of coal are typical gas-solid reactions; in the field of environmental protection, the pyrolysis and incineration treatment of solid waste also involve gas-solid reactions.

[0003] As an important gas-solid reaction device, the downer reactor is widely used in many industries. The unique structure and hydrodynamics characteristics of the downer reactor endow it with advantages such as high mass and heat transfer efficiency, prevention of solid material backmixing, and large processing capacity. Accurately measuring the kinetic parameters of the gas-solid reaction in the downer reactor is crucial for deeply understanding the reaction mechanism of powder materials, optimizing reaction conditions, and optimizing the design of the downer reactor. However, there are many deficiencies in the existing gas-solid reaction kinetics test methods and systems for downer reactors, such as inability to precisely control reaction conditions, inaccurate data acquisition, and difficulty in comprehensively analyzing the kinetics of complex gas-solid reactions. Summary of the Invention

[0004] Embodiments of this application provide a gas-solid reaction kinetics test system and method for a downer reactor, which can solve the problems existing in the existing gas-solid reaction kinetics test methods and systems for downer reactors, such as inability to precisely control reaction conditions, inaccurate data acquisition, and difficulty in comprehensively analyzing the kinetics of complex gas-solid reactions.

[0005] To achieve the above object, the technical solution of the embodiments of the present invention is as follows:

[0006] In a first aspect, embodiments of the present invention provide a gas-solid reaction kinetics test system for a downer reactor, characterized in that it includes a preheating device, an input pipe, a material collection bin, a downer gas-solid reaction furnace, a power compensation heat preservation sleeve, an output pipe, a gas concentration sensor, a feeding device, and an induced draft fan;

[0007] The preheating device is connected to the input port of the input pipe;

[0008] The output port of the input pipe is connected to the lower part of the downer gas-solid reaction furnace;

[0009] The material collection bin is arranged at the lower end of the downer gas-solid reaction furnace;

[0010] The power compensation heat preservation sleeve is sleeved on the downer gas-solid reaction furnace;

[0011] The input port of the output pipe is connected to the upper end of the downer gas-solid reaction furnace;

[0012] The feeding device is communicated with the outer wall of the output pipe close to the input port;

[0013] The gas concentration sensor is inserted into the output pipe;

[0014] The output port of the output pipe is communicated with the induced draft fan.

[0015] Combined with the first aspect, in a possible implementation manner, the downer reactor gas-solid reaction kinetics test system is characterized in that it further includes an electric heating pipe sleeve;

[0016] The electric heating pipe sleeve is sleeved on the input pipe.

[0017] Combined with the first aspect, in a possible implementation manner, the downer reactor gas-solid reaction kinetics test system further includes a heat exchanger;

[0018] The output port of the output pipe is communicated with the input port of the heat exchanger;

[0019] The output port of the heat exchanger is communicated with the induced draft fan.

[0020] Combined with the first aspect, in a possible implementation manner, the downer reactor gas-solid reaction kinetics test system further includes a dust collection device;

[0021] The output port of the heat exchanger is communicated with the input port of the dust collection device;

[0022] The output port of the dust collection device is communicated with the induced draft fan.

[0023] In the second aspect, an embodiment of the present invention provides a method for testing the gas-solid reaction kinetics of a downer reactor, based on the above-mentioned downer reactor gas-solid reaction kinetics test system, including:

[0024] Connect the preheating device to the input port of the input pipe, the output port of the input pipe is connected to the lower part of the downer gas-solid reaction furnace, the material collection bin is arranged at the lower end of the downer gas-solid reaction furnace, the power compensation heat preservation sleeve is sleeved on the downer gas-solid reaction furnace, the input port of the output pipe is connected to the upper end of the downer gas-solid reaction furnace, the feeding device is communicated with the outer wall of the output pipe close to the input port, the gas concentration sensor is inserted into the output pipe, and the output port of the output pipe is communicated with the induced draft fan;

[0025] According to the gas-solid reaction characteristics of the powder material, select the target parameters that can characterize the reaction progress of the powder material;

[0026] At least two sets of parallel experiments are carried out, and the error between the time-conversion rate data of the reaction products at the same time point of the isothermal reaction experiments of at least two sets of the parallel experiments is ±5%. Calculate the average value of the time-conversion rate data of at least two sets of the parallel experiments as the actual time-conversion rate;

[0027] Adopt the isothermal kinetics method to obtain the suspension reaction kinetics according to the actual time-conversion rate data;

[0028] Among them, each set of the parallel experiments performs at least four isothermal reaction experiments, and the preset temperature points of each isothermal reaction experiment are different, and the time-conversion rate data of each isothermal reaction experiment are obtained;

[0029] The isothermal reaction experiment includes:

[0030] Control the working state of the power compensation heat preservation sleeve, control the feeding amount of the feeding device into the downer gas-solid reaction furnace, adjust the gas flow rate at the input end of the preheating device, and control the air volume of the induced draft fan so that the downer gas-solid reaction furnace is stably maintained at the preset temperature point;

[0031] Select at least four time points to collect solid reaction products from the material collection bin or measure the gas reaction product concentration with a gas concentration sensor;

[0032] Calculate the conversion rate of the reaction product at each time point according to the target parameter, and obtain the time-conversion rate data.

[0033] Combined with the second aspect, in a possible implementation manner, the isothermal kinetics method includes the reduced time method, the integral method, the differential method, the isoconversional method or the double logarithmic method.

[0034] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0035] When the downflow bed reactor gas-solid reaction kinetics test system provided by the embodiment of the present invention is actually used, first install all components. Then, according to the gas-solid reaction characteristics of the powder material, select the target parameter that can characterize the reaction progress of the powder material. After that, perform at least two groups of parallel experiments, and ensure that the error between the time-conversion rate data of the reaction products at the same time point of the same isothermal reaction experiment in at least two groups of parallel experiments is ±5%. Calculate the average value of the time-conversion rate data of at least two groups of parallel experiments as the actual time-conversion rate. Adopt the isothermal kinetics method to obtain the suspension reaction kinetics according to the actual time-conversion rate data. Among them, each group of parallel experiments performs at least four isothermal reaction experiments, and the preset temperature points of each isothermal reaction experiment are different, and the time-conversion rate data of each isothermal reaction experiment are obtained. The isothermal reaction experiment includes: controlling the working state of the power compensation heat preservation sleeve, controlling the feeding amount of the feeding device into the downflow bed gas-solid reaction furnace, adjusting the gas flow rate at the input end of the preheating device, and controlling the air volume of the induced draft fan to keep the downflow bed gas-solid reaction furnace stable at the preset temperature point; select at least four time points to collect solid reaction products from the material collection bin or measure the gas reaction product concentration with a gas concentration sensor; calculate the conversion rate of the reaction product at each time point according to the target parameter, and obtain the time-conversion rate data. The test system of the present application is based on in-depth research on the gas-solid reaction characteristics, constructs a test system that can accurately control reaction conditions and data collection, and through precise control of reaction conditions and collection and analysis of data, can accurately determine the gas-solid reaction kinetics parameters of the downflow bed, and can conduct a comprehensive kinetic analysis of complex gas-solid reactions, which helps to deeply understand the reaction mechanism and optimize the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description in the embodiments of the present invention. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic structural diagram of the downflow bed reactor gas-solid reaction kinetics test system provided by the embodiment of the present application;

[0038] Figure 2 It is the reaction decomposition rate obtained from the experimental analysis in Embodiment 1 of the present application;

[0039] Figure 3 It is the fitting diagram of ln[-ln(1-α)]~lnt at 400°C in Embodiment 1 of the present application;

[0040] Figure 4 It is the fitting diagram of ln[-ln(1-α)]~lnt at 500°C in Embodiment 1 of the present application;

[0041] Figure 5 This is the fitting graph of ln[-ln(1-α)]~lnt at 600°C in the first embodiment of the present application;

[0042] Figure 6 This is the fitting graph of ln[-ln(1-α)]~lnt at 700°C in the first embodiment of the present application;

[0043] Figure 7 This is the fitting graph of lnk~1 / T in the first embodiment of the present application.

[0044] Icon: 1 - Preheating device; 2 - Input pipe; 3 - Material collection bin; 4 - Downer gas-solid reaction furnace; 5 - Power compensation heat preservation sleeve; 6 - Output pipe; 7 - Feeding device; 8 - Induced draft fan; 9 - Monitoring and control device; 10 - Electric heating pipe sleeve; 11 - Heat exchanger; 12 - Dust collection device; 13 - Gas concentration sensor. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. The terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0047] Please refer to Figure 1As shown in the figure, an embodiment of the present invention provides a kinetic test system for gas-solid reaction in a downer reactor, which includes a preheating device 1, an input pipe 2, a material collection bin 3, a downer gas-solid reaction furnace 4, a power compensation insulation sleeve 5, an output pipe 6, a gas concentration sensor 13, a feeding device 7 and a draft fan 8.

[0048] A high-precision mass flow controller is connected to the preheating device 1 to supply reaction gas to the preheating device 1, and the feeding accuracy is ±0.2 g / kg.

[0049] The preheating device 1 is connected to the input port of the input pipe 2. The preheating device 1 includes a preheater, a gas valve, a first temperature sensor and a heating element. The gas valve is arranged at the input end of the preheater to control the gas flow. The first temperature sensor is arranged on the side wall of the preheater to monitor the gas temperature. The heating element is wound around the preheater to preheat the gas, and the heating temperature is adjustable. The output end of the preheater is connected to the input port of the input pipe 2. The preheating device 1 is used to preheat the gas participating in the reaction to ensure that the gas reaches a suitable temperature when entering the downer gas-solid reaction furnace 4. The gas preheating temperature is controlled by the heating element.

[0050] The output port of the input pipe 2 is connected to the lower part of the downer gas-solid reaction furnace 4.

[0051] The material collection bin 3 is arranged at the lower end of the downer gas-solid reaction furnace 4 to collect the reaction products (solid reaction products) for subsequent analysis.

[0052] The power compensation insulation sleeve 5 is sleeved on the downer gas-solid reaction furnace 4. The outside is wrapped with thermal insulation materials to reduce heat loss. The power compensation insulation sleeve 5 is used to ensure the stability of the internal temperature of the gas-solid reaction device so that the gas-solid two phases react at a set temperature.

[0053] The input port of the output pipe 6 is connected to the upper end of the downer gas-solid reaction furnace 4.

[0054] The downer gas-solid reaction furnace 4 provides a place for the gas-solid reaction to occur, enabling the gas-solid two phases to be fully suspended and contacted to ensure the uniformity of the reaction, and can withstand the temperature and pressure during the reaction (a second temperature sensor and a pressure sensor are arranged on the side wall of the downer gas-solid reaction furnace 4 to measure the temperature and pressure inside the downer gas-solid reaction furnace 4 in real time, so that the temperature fluctuation in the reaction zone of the downer gas-solid reaction furnace 4 is controlled within ±3°C to ensure that the reaction proceeds under the set temperature conditions. The power compensation insulation sleeve 5 automatically adjusts the heating power according to the data fed back by the second temperature sensor). There is a special coating inside the downer gas-solid reaction furnace 4 to prevent the powder material from sticking to the wall and promote the uniform mixing of gas and solid.

[0055] The feeding device 7 is communicated with the outer wall of the output pipe 6 near the input port. The feeding device 7 includes a high-precision screw feeder or a vibrating feeder, and the feeding speed is adjusted with high precision by adjusting the motor speed or the vibration frequency. It can accurately control the feeding amount and feeding speed of the powder material, and convey the powder material to the downer gas-solid reaction furnace 4.

[0056] The gas concentration sensor 13 is inserted into the output pipe 6, and can measure the concentration of the reaction product (gas reaction product) output from the output pipe 6.

[0057] The output port of the output pipe 6 is communicated with the induced draft fan 8. The induced draft fan 8 can provide power for the gas flow in the entire downer reactor gas-solid reaction kinetics test system, ensure that the gas can circulate in the system, and guarantee the gas supply required for the reaction.

[0058] A flow meter and an automatic regulating valve are also arranged at the input end of the induced draft fan 8. The induced draft fan 8, the flow meter and the automatic regulating valve work together to control the ventilation pressure fluctuation of the system within ±15 Pa, and realize stable ventilation.

[0059] Furthermore, the downer reactor gas-solid reaction kinetics test system further includes an electric heating tube sleeve 10. The electric heating tube sleeve 10 is sleeved on the input pipe 2, so as to further preheat the input reaction gas.

[0060] As Figure 1 shown, the downer reactor gas-solid reaction kinetics test system further includes a heat exchanger 11. The output port of the output pipe 6 is communicated with the input port of the heat exchanger 11. The output port of the heat exchanger 11 is communicated with the induced draft fan 8.

[0061] The heat exchanger 11 can exchange heat for the substance output from the output pipe 6, cool down the output substance, and utilize the exchanged heat at the same time.

[0062] Furthermore, as Figure 1 shown, the downer reactor gas-solid reaction kinetics test system further includes a dust collection device 12. The output port of the heat exchanger 11 is communicated with the input port of the dust collection device 12. The output port of the dust collection device 12 is communicated with the induced draft fan 8.

[0063] The dust collection device 12 includes a cyclone separator or a filtering mechanism, and can collect the fine solid particles generated after the reaction to prevent damage to the subsequent equipment.

[0064] The system further includes a monitoring and control device 9 (such as a computer). Components such as the first temperature sensor, the second temperature sensor, the pressure sensor, the heating element, the power compensation thermal insulation sleeve 5, the flowmeter, and the automatic regulating valve are all electrically connected to the monitoring and control device 9. The monitoring and control device 9 can monitor and control data such as temperature, pressure, flow rate, and concentration in real time, perform analysis and processing, and output control signals to adjust the operating parameters to ensure that the system is in a stable operating state. At the same time, the collected data is stored and processed for subsequent kinetic calculation and analysis.

[0065] When the downer reactor gas-solid reaction kinetics test system provided by the embodiment of the present invention is actually used, first, all components are installed. Then, according to the gas-solid reaction characteristics of the powder material, a target parameter capable of characterizing the reaction progress of the powder material is selected. After that, at least two groups of parallel experiments are performed, and the error between the time-conversion rate data of the reaction products at the same time point of the same isothermal reaction experiment of at least two groups of parallel experiments is ±5%. Calculate the average value of the time-conversion rate data of at least two groups of parallel experiments as the actual time-conversion rate. Using the isothermal kinetics method, the suspension reaction kinetics is obtained based on the actual time-conversion rate data. Among them, each group of parallel experiments performs at least four isothermal reaction experiments, and the preset temperature points of each isothermal reaction experiment are different. The time-conversion rate data of each isothermal reaction experiment is obtained. The isothermal reaction experiment includes: controlling the working state of the power compensation thermal insulation sleeve 5, controlling the feeding amount of the feeding device 7 into the downer gas-solid reaction furnace 4, adjusting the gas flow rate at the input end of the preheating device 1, and controlling the air volume of the induced draft fan 8 to keep the downer gas-solid reaction furnace 4 stably at the preset temperature point; selecting at least four time points to collect solid reaction products from the material collection bin 3 or measuring the gas reaction product concentration with the gas concentration sensor 13; calculating the conversion rate of the reaction product at each time point according to the target parameter, and obtaining the time-conversion rate data. Based on the in-depth study of the gas-solid reaction characteristics, the test system of the present application constructs a test system that can accurately control the reaction conditions and data collection. By precisely controlling the reaction conditions and collecting and analyzing data, the kinetic parameters of the downer gas-solid reaction can be accurately measured, and a comprehensive kinetic analysis of complex gas-solid reactions can be carried out, which helps to deeply understand the reaction mechanism and optimize the reaction process.

[0066] The test system of the present invention has a high degree of integration, and each device works in coordination, can remain stable and reliable during long-term operation, reduce experimental errors, and provides an efficient platform for the study of downer gas-solid reaction kinetics. It has universality and can be applied to a variety of gas-solid reaction systems, providing important technical support for related research and production in industries such as chemical engineering and energy.

[0067] The test system adopted in the present invention has the functions of stable feeding, stable ventilation, adjustable residence time, and the ability to collect and measure reaction products, and can maintain the temperature of the reaction zone constant and the reaction in a stable state under the set parameters.

[0068] Another embodiment of the present invention provides a method for testing the gas-solid reaction kinetics of a downflow bed reactor. Based on the above-mentioned gas-solid reaction kinetics test system of the downflow bed reactor, it includes:

[0069] Connect the preheating device 1 to the input port of the input pipe 2, connect the output port of the input pipe 2 to the lower part of the downflow bed gas-solid reaction furnace 4, set the material collection bin 3 at the lower end of the downflow bed gas-solid reaction furnace 4, sleuth the power compensation heat preservation sleeve 5 on the downflow bed gas-solid reaction furnace 4, connect the input port of the output pipe 6 to the upper end of the downflow bed gas-solid reaction furnace 4, connect the feeding device 7 to the outer wall of the output pipe 6 near the input port, insert the gas concentration sensor 13 into the output pipe 6, and connect the output port of the output pipe 6 to the induced draft fan 8.

[0070] According to the gas-solid reaction characteristics of the powder material, select the target parameters that can characterize the reaction progress of the powder material. For the target parameters that can characterize the reaction progress of the powder material, the target parameters are physical quantities directly related to the reaction degree. For example, the target parameters are (1) the content of a certain component (for example, in the case of metal oxide reduction reaction, the change in the content of metal oxide in the solid before and after the reaction can be measured to reflect the reaction progress). (2) the concentration of a certain component (for gaseous reactants or products in the reaction system, its concentration change can be monitored in real time by a gas analyzer, such as the change in the concentration of carbon monoxide during the reaction). (3) the flow rate of the powder material. (4) the mass of the powder material. (5) the loss on ignition of the powder material (in high-temperature gas-solid reactions, the loss on ignition of solid materials is an index of the reaction degree, which is determined by accurately weighing the mass of the solid before and after the reaction). (6) parameters related to the quantification of the powder material (weight, volume, electrode potential, conductivity, current, voltage, spectral wavelength, spectral intensity or spectral absorption, etc. For example, in some gas-solid reactions with electrochemical characteristics, the change in electrode potential can be used to characterize the reaction progress).

[0071] Perform at least two groups of parallel experiments, and ensure that the error between the time-conversion rate data of the reaction products at the same time point of the same isothermal reaction experiment of at least two groups of parallel experiments is ±5%. If not satisfied, repeat the experiment until the error requirement is met, and calculate the average value of the time-conversion rate data of at least two groups of parallel experiments as the actual time-conversion rate.

[0072] Adopt the isothermal kinetics method to obtain the suspension reaction kinetics according to the actual time-conversion rate data, so as to obtain the activation energy, mechanism function, pre-exponential factor and kinetic equation of the suspension reaction.

[0073] Among them, each group of parallel experiments performs at least four isothermal reaction experiments, with different preset temperature points for each isothermal reaction experiment, and the time-conversion rate data of each isothermal reaction experiment is obtained to comprehensively investigate the reaction characteristics at different temperatures. For example, when studying a certain gas-solid catalytic reaction, 400 °C, 500 °C, 600 °C, and 700 °C are selected as the controlled temperatures. Each temperature point is controlled by a closed-loop system composed of a heating element (such as an electric heating wire) and a first temperature sensor (such as a thermocouple) to keep the temperature fluctuation within ±3 °C.

[0074] Among them, the isothermal kinetic methods include the reduced time method, the integral method, the differential method, the isoconversional method, or the double logarithmic method (lnln method).

[0075] Reduced time method: By performing specific mathematical transformations and processing on the "time-conversion rate" data, the reduced time concept is used to calculate the reaction kinetic parameters. For example, according to the calculation formula of the reduced time method, the time and conversion rate data at different temperatures are substituted to calculate the kinetic parameters such as the activation energy and mechanism function of the reaction.

[0076] Integral method: Integrate the "time-conversion rate" data and fit it with the integral form of the kinetic model to obtain the kinetic parameters. For example, compare and fit the experimental data with the integral equations of different kinetic models, and determine the kinetic equation and related parameters of the reaction according to the fitting results.

[0077] The isothermal reaction experiment includes:

[0078] Control the working state of the power compensation thermal insulation sleeve 5, control the feeding amount of the feeding device 7 into the downer gas-solid reaction furnace 4, adjust the gas flow rate at the input end of the preheating device 1, and control the air volume of the induced draft fan 8 so that the downer gas-solid reaction furnace 4 is stably maintained at the preset temperature point.

[0079] Specifically, use the monitoring and control device 9 (such as a computer) to adjust the operating parameters to control the working state of the power compensation thermal insulation sleeve 5, control the feeding amount of the feeding device 7 into the downer gas-solid reaction furnace 4 (use a high-precision feeding device 7 (such as a screw feeder) to control the feeding amount of the powder material, and ensure that the feeding amount of the powder material is stable during the experiment. The feeding amount of the powder material during the experiment is fixed at 5 kg / h to 6 kg / h, and the measurement error does not exceed 1%), adjust the gas flow rate at the input end of the preheating device 1 (such as a valve, mass flow controller), and control the air volume of the induced draft fan 8 (to control the gas flow rate) so that the downer gas-solid reaction furnace 4 is stably maintained at the preset temperature point.

[0080] The residence time of the powder material in the downflow bed gas-solid reaction furnace 4 is controlled by adjusting the pipe diameter, pipe length of the downflow bed reactor and operating parameters (such as gas flow rate, powder material feeding rate) to control the residence time of the powder material in the downflow bed gas-solid reaction furnace 4. For example, in the downflow bed gas-solid reaction furnace 4 with a pipe diameter of 900 mm and a pipe length of 4 m, the parameters are adjusted to make the material residence time reach a predetermined value (such as 8 s), and the error is controlled within ±0.5 s.

[0081] Select at least four time points to collect the solid reaction product from the material collection bin 3 or measure the gas reaction product concentration with the gas concentration sensor 13. That is, at each temperature point, select at least four time points for the experiment (for example, at 500 °C, select 0.921 s, 1.324 s, 1.767 s and 2.688 s (calculated time, not directly measured) for the experiment). The collected reaction products are used for relevant quantitative analysis. These at least four time points should ensure that the reaction products at different reaction stages can be obtained to ensure that the progress of the reaction is captured at different time scales.

[0082] Calculate the conversion rate of the reaction product at each time point according to the target parameter, and obtain the time-conversion rate data, that is, conduct a quantitative analysis on the collected reaction products.

[0083] For example, for the collected solid sample, the conversion rate of the solid material is calculated by measuring the change in the content of the key components through chemical analysis methods. For the gas sample, the conversion rate of the gas reactant is calculated by measuring the change in the concentration of the reaction gas.

[0084] During the experiment, the gas flow rate and the feeding amount of the powder material are kept stable to avoid interference with the experimental results caused by fluctuations in material supply.

[0085] The test method of this application is based on in-depth research on the gas-solid reaction characteristics, constructs a test system that can accurately control the reaction conditions and data acquisition. By precisely controlling the reaction conditions and collecting and analyzing data, the kinetic parameters of the downflow bed gas-solid reaction can be accurately determined, and a comprehensive kinetic analysis of complex gas-solid reactions can be carried out, which helps to deeply understand the reaction mechanism and optimize the reaction process.

[0086] Example 1

[0087] The solid material is a certain carbon-containing mineral. Through the downflow bed reactor gas-solid reaction kinetic test system and method of the present invention, the decarbonization gas-solid reaction kinetics of the carbon-containing mineral is determined.

[0088] Connect the preheating device 1 to the input port of the input pipe 2. Connect the output port of the input pipe 2 to the lower part of the downer gas-solid reaction furnace 4. The material collection bin 3 is arranged at the lower end of the downer gas-solid reaction furnace 4. The power compensation heat preservation sleeve 5 is sleeved on the downer gas-solid reaction furnace 4. The input port of the output pipe 6 is connected to the upper end of the downer gas-solid reaction furnace 4. The feeding device 7 communicates with the outer wall of the output pipe 6 near the input port. The gas concentration sensor 13 is inserted into the output pipe 6. The output port of the output pipe 6 is communicated with the induced draft fan 8.

[0089] According to the gas-solid reaction characteristics of carbon-containing minerals, select the total carbon element content as the target parameter that can characterize the reaction progress of the powder material. The analysis method uses a carbon-sulfur analyzer.

[0090] Perform at least two groups of parallel experiments, and ensure that the error between the time-conversion rate data of the reaction products at the same time point of the same isothermal reaction experiment in at least two groups of parallel experiments is ±5%. Calculate the average value of the time-conversion rate data of at least two groups of parallel experiments as the actual time-conversion rate.

[0091] Among them, each group of parallel experiments performs at least four isothermal reaction experiments. According to the characteristics of the oxidation reaction of carbon-containing minerals, the preset temperature points of each isothermal reaction experiment are 400°C, 500°C, 600°C, and 700°C respectively, and the time-conversion rate data of each isothermal reaction experiment are obtained.

[0092] The isothermal reaction experiment includes:

[0093] Control the working state of the power compensation heat preservation sleeve 5, control the feeding amount of the feeding device 7 into the downer gas-solid reaction furnace 4, adjust the gas flow rate at the input end of the preheating device 1, and control the air volume of the induced draft fan 8 so that the downer gas-solid reaction furnace 4 is stably maintained at the preset temperature point (400°C or 500°C or 600°C or 700°C).

[0094] At 400°C, select 0.921s, 1.324s, 1.767s, and 2.688s to measure the gas reaction product concentration with the gas concentration sensor 13. These four time points of 0.921s, 1.324s, 1.767s, and 2.688s can be calculated by the following method by adjusting the air volume of the induced draft fan 8 and the length l of the reaction zone of the downer gas-solid reaction furnace 4 covered by the power compensation heat preservation sleeve 5.

[0095] First, calculate the sedimentation velocity v of the powder material.

[0096] For smaller powder particles (diameter < 0.1mm) with a Reynolds number Re < 0.1, laminar sedimentation, and Stokes' Law is used:

[0097]

[0098] Wherein, v is the sedimentation velocity of the powder material (m / s), g is the acceleration due to gravity (9.81 m / s 2 ), d is the diameter of the powder material (m), ρ s is the density of the powder material (kg / m 3 ), ρ f is the fluid density (kg / m 3 ), and μ is the dynamic viscosity of the fluid (Pa·s).

[0099] For larger powder materials with a Reynolds number Re > 0.1, the Alch-Allen formula (Allen’s Formula) is adopted,

[0100]

[0101] Wherein, v is the sedimentation velocity of the powder material (m / s), g is the acceleration due to gravity (9.81 m / s 2 ), d is the diameter of the powder material (m), ρ s is the density of the powder material (kg / m 3 ), ρ f is the fluid density (kg / m 3 ), C d is the drag coefficient, which can be determined by an empirical formula:

[0102]

[0103] Wherein, Re is the Reynolds number of the powder material:

[0104]

[0105] Wherein, ρ f is the fluid density (kg / m 3 ), v is the sedimentation velocity of the powder material (m / s), d is the diameter of the powder material (m), and μ is the dynamic viscosity of the fluid (Pa·s).

[0106] Then, the ratio of the length l of the reaction zone of the downer gas-solid reaction furnace 4 covered by the power compensation insulation sleeve 5 to the sedimentation velocity of the powder material is the time t, i.e., t = l / v.

[0107] At 500 °C, select 0.921 s, 1.324 s, 1.767 s, and 2.688 s to measure the gas reaction product concentration with the gas concentration sensor 13.

[0108] At 600 °C, select 0.921 s, 1.324 s, 1.767 s, and 2.688 s to measure the gas reaction product concentration with the gas concentration sensor 13.

[0109] At 700 °C, select 0.921 s, 1.324 s, 1.767 s, and 2.688 s to measure the concentration of gas reaction products with the gas concentration sensor 13.

[0110] During the experiment, the feeding rate of the powder material was fixed at 5.0 kg / h, and the measurement error was not more than 1%.

[0111] Calculate the conversion rate of the reaction product at each time point according to the target parameters, and obtain the time-conversion rate data. Conduct a total carbon element analysis on the collected gas samples, and calculate the conversion rates at different temperatures and times. Calculate the average of the time-conversion rate data of at least two groups of parallel experiments as the actual time-conversion rate, and organize the results in the form of "time-conversion rate" data at each temperature. The time-conversion rate relationship obtained from the experimental analysis is shown in the appendix Figure 2 .

[0112] Adopt the isothermal kinetics method (double logarithm method (lnln method)) to obtain the suspension reaction kinetics according to the actual time-conversion rate data.

[0113] The calculation steps are as follows:

[0114] (1) Plot ln[-ln(1-α)] as the ordinate and lnt as the abscissa, perform a linear fit, find the slope m value, and obtain the reaction rate constant k from the intercept.

[0115] The fitting results of ln[-ln(1-α)]~lnt at four temperatures of 400 °C, 500 °C, 600 °C, and 700 °C are shown in Figure 3 , Figure 4 , Figure 5 and Figure 6 . The m values are 1.375, 1.020, 1.034, and 1.037 respectively. The values of the intercept lnk are -3.037, -2.368, -1.934, and -1.528 respectively.

[0116] (2) Determine the mechanism function according to m.

[0117] Figure 3 , Figure 4 , Figure 5 and Figure 6 The average of the m values in is 1.117, and the m value of the chemical reaction (n = 4) mechanism function is 1.117. The two are close, so the determined mechanism function is the chemical reaction mechanism (n = 4).

[0118] (3) Plot lnk as the ordinate and 1 / T as the abscissa for a linear fit, and obtain the activation energy E from the slope and the pre-exponential factor A from the intercept.

[0119] The fitting result of lnk~1 / T is shown in Figure 7, the slope of the linear fitting is -4847.65 and the intercept is 4.140. It can be calculated that the activation energy E is 40.30 kJ / mol and the pre-exponential factor A is 62.80 s -1 .

[0120] (4) According to the determined mechanism function, activation energy E, and pre-exponential factor A, the kinetic equation for the suspension reaction is obtained.

[0121] In this embodiment, the determined kinetic parameters are as follows: the reaction mechanism is a chemical reaction (n = 4), the activation energy E = 40.30 kJ / mol, and the pre-exponential factor A = 62.80 s -1 . Therefore, the kinetic equation for the suspension reaction of sample desulfurization is as follows:

[0122]

[0123] It can be seen from the above Example 1 that the system of the present invention performs well in aspects such as stable feeding, ventilation, residence time control, reaction product collection, and analysis of the gas composition after the reaction, ensuring the stability of the experimental process and the accuracy of the experimental results. The present invention can comprehensively and accurately solve the problem that traditional kinetic methods cannot be used for the gas-solid reaction kinetics in the downer bed suspension state, and can not only provide a basic research method for the development and application of suspension technology, but also provide a basis for the development of relevant suspension kinetic experimental devices.

[0124] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0125] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. A gas-solid reaction kinetics test system for a downflow reactor, characterized in that: It includes a preheating device, an input pipe, a material collecting bin, a down-bed gas-solid reactor, a power compensation insulation sleeve, an output pipe, a gas concentration sensor, a feeding device and an induced draft fan; The preheating device is connected to the input port of the input pipe; The output port of the input pipe is connected to the lower part of the down-bed gas-solid reactor; The material collecting bin is arranged at the lower end of the down-bed gas-solid reactor; The power compensation insulation sleeve is sleeved on the down-bed gas-solid reactor; The input port of the output pipe is connected to the upper end of the down-bed gas-solid reactor; The feeding device is in communication with the outer wall of the output pipe close to the input port; The gas concentration sensor is inserted into the output pipe; The output port of the output pipe is communicated with the induced draft fan.

2. The gas-solid reaction kinetics test system of the downer reactor according to claim 1, characterized in that: Also includes an electric heating sleeve; The electric heating pipe sleeve is sleeved on the input pipe.

3. The gas-solid reaction kinetics test system of the downer reactor according to claim 1, characterized in that: Also included is a heat exchanger; The output port of the output pipe is connected to the input port of the heat exchanger; The output port of the heat exchanger is communicated with the induced draft fan.

4. The gas-solid reaction kinetics test system of the downer reactor according to claim 3, characterized in that: Also includes a dust collection device; The output port of the heat exchanger is connected to the input port of the dust collecting device; The output port of the dust collecting device is communicated with the induced draft fan.

5. A method for testing gas-solid reaction kinetics in a downflow reactor, characterized in that: The gas-solid reaction kinetics test system of the downer reactor according to any one of claims 1 to 4 comprises: The preheating device is connected to the input port of the input pipe, the output port of the input pipe is connected to the lower part of the down-going bed gas-solid reactor, the material collecting bin is arranged at the lower end of the down-going bed gas-solid reactor, the power compensation insulation sleeve is arranged on the down-going bed gas-solid reactor, the input port of the output pipe is connected to the upper end of the down-going bed gas-solid reactor, the feeding device is communicated with the outer wall of the output pipe near the input port, the gas concentration sensor is inserted in the output pipe, and the output port of the output pipe is communicated with the induced draft fan; According to the gas-solid reaction characteristics of the powder material, select a target parameter that can characterize the reaction progress of the powder material; Perform at least two sets of parallel experiments, and achieve an error of ±5% between the time-conversion rate data of the reaction products at the same time point of the isothermal reaction experiment in at least two sets of parallel experiments, and calculate the average value of the time-conversion rate data of at least two sets of parallel experiments as the actual time-conversion rate; Using an isothermal kinetic method, the suspension reaction kinetics are obtained based on the actual time-conversion rate data; Wherein, each group of the parallel experiments performs at least four isothermal reaction experiments, and the preset temperature point of each isothermal reaction experiment is different, and the time-conversion rate data of each isothermal reaction experiment is obtained; The isothermal reaction experiment includes: Controlling the working state of the power compensation insulation sleeve, controlling the feeding amount of the feeding device into the down-bed gas-solid reactor, adjusting the gas flow at the input end of the preheating device, and controlling the air volume of the induced draft fan, so that the down-bed gas-solid reactor is stably maintained at the preset temperature point; Select at least four time points to collect solid reaction products from the material collection bin or measure the concentration of gaseous reaction products using a gas concentration sensor; The conversion rate of the reaction product at each time point is calculated according to the target parameters, and time-conversion rate data is obtained.

6. The method for testing gas-solid reaction kinetics of a downer reactor according to claim 5, characterized in that: The isothermal kinetic method includes the reduced time method, the integral method, the differential method, the equal conversion rate method or the double logarithmic method.

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