Experimental method for catalyzing high-pressure gasification reaction of high-temperature coke by CaO under different atmospheres

Abstract

The invention belongs to the technical field of dry pulverized coal gasifiers, and discloses an experimental method for CaO to catalyze high-temperature coke high-pressure gasification reaction under different atmospheres, which comprises the following specific steps: step 1, preparing experimental raw materials and pretreating to select representative coal types; the diffusion environment of the industrial gasifier is simulated by establishing a cooperative regulation and control mechanism of pressure, gas velocity and pore structure, the thickness of a boundary layer is calculated according to the Fick diffusion law, a diffusion resistance quantitative relational expression is constructed for dynamic correction, and a variable diffusion strength experimental group is designed to quantify diffusion contribution. The diffusion and reaction rate ratio is quantitatively evaluated through a Weber number model, a catalysis and blank control synchronous experiment is carried out at the same time, a catalysis efficiency factor is calculated, a catalysis-diffusion synergistic phase diagram is drawn, and a reaction control region, a diffusion control region and a transition region are definitely defined; and the risk that the reaction stagnation caused by the fact that the high-pressure diffusion retardation effect is misjudged as catalytic activity attenuation or pore collapse is mistakenly attributed to catalyst deactivation is eliminated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dry pulverized coal gasifiers, and particularly relates to an experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification reaction under different atmospheres. BACKGROUND

[0002] As a core equipment of modern coal chemical industry, the two-stage dry pulverized coal gasifier has a process that is divided into two stages of high-temperature pyrolysis and catalytic reforming: the first stage realizes rapid cracking of coal powder in an oxygen-rich environment, and the second stage reduces the temperature of synthesis gas by using the coal gasification reaction to realize reaction heat recovery, and finally realizes efficient conversion of coal into hydrogen and carbon monoxide synthesis gas.

[0003] The gasifier is actually operated in a harsh environment of high pressure and multiple atmosphere interactions, and the reaction process is simultaneously affected by the complex coupling effect of gas diffusion limitation and catalytic kinetics. In order to accurately optimize the operating parameters of the industrial gasifier and design the catalyst, it is urgent to obtain the intrinsic kinetic characteristics of calcium oxide catalyzed coal char in different atmospheres under high pressure conditions and the quantitative relationship between the intrinsic kinetic characteristics and the diffusion effect. However, the existing experimental technical system has significant limitations. Since the gas diffusion effect and the chemical reaction are strongly coupled under high pressure conditions, but the existing experimental scheme lacks a coordinated regulation mechanism for pressure, gas velocity and pore structure, resulting in mass transfer noise mixed in key parameters such as apparent activation energy and reaction order, which exceeds the reasonable threshold, and ultimately causes distortion of the basis for catalyst selection of the industrial gasifier, for example, misjudging the high-pressure diffusion retardation effect as catalytic activity decay, or incorrectly attributing the reaction stagnation caused by pore collapse to catalyst deactivation. Therefore, it is necessary to establish a high-pressure standardized experimental method covering all working conditions. SUMMARY

[0004] In view of the deficiencies of the prior art, the application provides an experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification reaction under different atmospheres, which has the advantages of high precision.

[0005] To achieve the above purpose, the application provides the following technical scheme: an experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification reaction under different atmospheres, and the specific steps are as follows:

[0006] Step 1: Preparation and pretreatment of experimental raw materials

[0007] Select a representative coal, crush and sieve to obtain a coal powder sample with a particle size range of 75 microns to 150 microns, place the coal powder in a high-purity nitrogen tube furnace, and heat to 900 degrees Celsius at a heating rate of 10 degrees Celsius per minute, and keep the temperature constant for 30 minutes to obtain high-temperature coal char;

[0008] Calcium oxide catalyst powder was mixed with deionized water in a mass ratio of 1:5 and stirred for 60 minutes to form a suspension. Coal char was added and fully impregnated to ensure that the catalyst loading reached 10% of the coal char mass. The calcium oxide-loaded coal char sample was dried at 105 degrees Celsius for 12 hours and sealed for storage.

[0009] Step 2: Preparation of high-pressure gasification reaction system

[0010] Use a high-pressure thermogravimetric analyzer or a customized high-pressure fixed-bed reactor system. The system must include a precision temperature control device, a multi-channel gas mixing module, a high-precision pressure sensor, and a real-time gas composition analyzer. Calibrate the gas flow controller to ensure that the flow error is less than 1%.

[0011] Equipped with a steam generator, liquid water is delivered to the high-temperature vaporizer through a precision injection pump and then fed into the reactor through a preheating pipeline to avoid steam condensation;

[0012] Step 3: Set gas diffusion conditions

[0013] Design a variable diffusion intensity experiment: By adjusting the system total pressure, gas linear velocity, and coal char pore structure, the diffusion environment of an industrial gasifier is simulated. The gas boundary layer thickness is calculated according to Fick's diffusion law, and a quantitative relationship for diffusion resistance is established for subsequent dynamic correction.

[0014] Step 4: Gasification reaction kinetics experiment

[0015] A 300 mg sample of calcium oxide-loaded coal char was placed flat in a quartz crucible in a high-pressure reactor. A high-purity nitrogen gas flow rate of 50 ml / min was introduced for 20 minutes. The temperature was then raised at 15°C / min to a preset temperature. After the temperature stabilized, the system pressure was maintained at the target value.

[0016] Switch to target reaction atmosphere:

[0017] Carbon dioxide atmosphere: 100% carbon dioxide by volume, with a total flow rate of 100 ml per minute;

[0018] Water vapor atmosphere: nitrogen carrier gas is introduced to mix with water vapor, and the steam saturation is monitored by a dew point sensor;

[0019] Oxygen atmosphere: A mixture of 5% oxygen and 95% carbon dioxide by volume was introduced to simulate partial oxidation;

[0020] The sample mass change is recorded in real time through thermogravimetric signals, and the outlet gas composition is collected simultaneously. The concentrations of carbon monoxide, hydrogen, and carbon dioxide are analyzed by gas chromatography. The experiment is repeated at least three times for each condition until the sample mass change rate meets the requirements and the reaction is determined to be terminated.

[0021] Step 5: Data collection and processing

[0022] Carbon conversion was calculated according to the weight loss curve:

[0023]

[0024] Where m0is the initial mass, m t is the mass at time t, m ∞ is the mass of ash;

[0025] Reaction rate at different conversion was extracted:

[0026]

[0027] Where, dXis the increment of carbon conversion in a very short time dt; dtis the minimum sampling interval of experimental data; kis the pre-exponential factor; nis the reaction order; f(P g ) is the gas partial pressure function; T is the thermodynamic temperature of the reaction system; R is the ideal gas constant; E a is the apparent activation energy;

[0028] The apparent activation energy and pre-exponential factor were solved by Arrhenius curve, and the kinetic parameters of different atmospheres were compared;

[0029] Step six: analysis of catalyst effect and diffusion contribution

[0030] Blank control group experiment was carried out: under the same conditions, the coal char gasification kinetics without loading calcium oxide was tested, and the calcium oxide catalytic efficiency factor was calculated Based on the Weber number, the influence of gas diffusion was quantitatively evaluated:

[0031]

[0032] Where, D e is the effective diffusion coefficient; δ is the boundary thickness; k s is the intrinsic reaction rate constant; C g is the gas phase reactant concentration in the main flow area of the reactor; n is the reaction order of the gas phase reactant;

[0033] The catalysis-diffusion synergy phase diagram was drawn to define the reaction control area, diffusion control area and transition area;

[0034] Step seven: experimental quality control

[0035] The fixed carbon, volatile matter and ash content of each batch of coal char sample were determined by proximate analysis, and the specific surface area was measured by nitrogen adsorption BET method for three times sampling average value, and the calcium oxide dispersity was characterized by scanning electron microscopy combined with energy spectrum analysis; the gas standard was calibrated by using standard gas calibration analyzer, and the detection limit of carbon dioxide, hydrogen and carbon monoxide was less than 5 parts per million;

[0036] Data validity determination: the carbon conversion rate deviation of the same condition repeated experiment is not more than plus or minus 3%, otherwise retest;

[0037] Residual mineral analysis: the sample after reaction is identified by X-ray diffraction to determine the phase change of the catalyst.

[0038] Preferably, in the process of adding coal coke for impregnation in step one, a dynamic adsorption-equalization filtration drying method is used, the coal coke is placed in a constant temperature 30℃ suspension and ultrasonically oscillated for 30 minutes, and then centrifuged at 2000 revolutions per minute for 60 seconds.

[0039] Preferably, the impregnation container in step one is limited to use polytetrafluoroethylene material to avoid metal ion pollution.

[0040] Preferably, in the water vapor atmosphere experiment in step four, the dew point sensor needs to record the steam saturation degree every 10 minutes, and when the saturation degree is less than 95%, the experiment should be immediately suspended to check the vaporization device.

[0041] Preferably, the reaction termination in step four needs to meet two conditions at the same time, the sample mass change rate is less than one thousandth per minute for three consecutive minutes, and the outlet carbon monoxide concentration fluctuation range is less than 1%.

[0042] Preferably, the blank control group experiment in step six needs to be carried out at the same time as each group of catalytic experiments, and the ash composition of the blank sample needs to be completely consistent with the catalytic sample.

[0043] Preferably, the high-pressure reactor in step four has a maximum pressure that does not exceed 80% of the rated pressure of the equipment, and the oxygen partial pressure is strictly limited to below 0.5 MPa to prevent the risk of deflagration.

[0044] Preferably, the X-ray diffraction analysis of residual mineral analysis in step seven needs to be completed within two hours after the reaction ends to avoid phase change of intermediate products such as calcium carbonate due to air contact.

[0045] Preferably, the high-pressure gasification reaction system preparation in step two includes airtightness test of the high-pressure reactor, filling 3 MPa nitrogen for pressure preservation for 30 minutes, and the pressure drop is not more than 5 parts per thousand to be qualified.

[0046] Compared with the prior art, the beneficial effects of the present application are as follows:

[0047] By establishing a synergistic control mechanism of pressure, gas velocity and pore structure to simulate the diffusion environment of industrial gasifier, the boundary layer thickness is calculated according to Fick's diffusion law and the quantitative relationship of diffusion resistance is constructed for kinetic correction, and a variable diffusion intensity experimental group is designed to quantify the diffusion contribution, the ratio of diffusion to reaction rate is quantitatively evaluated by the Weber number model, and the catalytic and blank control synchronous experiments are implemented, the catalytic efficiency factor is calculated and the catalytic-diffusion synergistic phase diagram is drawn, the reaction control area, diffusion control area and transition area are clearly defined, the risk of misjudging the high pressure diffusion retardation effect as the catalyst activity attenuation or the reaction stagnation caused by the pore collapse is avoided, the dynamic adsorption-equilibrium filter drying method is used to improve the catalyst dispersion, and the double reaction termination conditions are combined to ensure that the key parameters such as apparent activation energy and reaction order are not disturbed by mass transfer noise, and finally a reproducible, high-precision and full-working-condition covering industrial gasification reaction kinetics experimental benchmark is constructed. DETAILED DESCRIPTION

[0048] All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0049] The embodiment of the present application provides an experimental method for CaO catalytic high-temperature coal coke high-pressure gasification reaction under different atmospheres, and the specific steps are as follows:

[0050] Step 1: Preparation and pretreatment of experimental raw materials

[0051] Representative coal is selected, coal powder samples with a particle size range of 75 microns to 150 microns are obtained by crushing and sieving, the coal powder is placed in a high-purity nitrogen tube furnace, the temperature is raised to 900 degrees Celsius at a rate of 10 degrees Celsius per minute, and the temperature is kept constant for 30 minutes, and high-temperature coal coke is prepared;

[0052] The calcium oxide catalyst powder is mixed with deionized water at a mass ratio of 1:5, stirred for 60 minutes to form a suspension, and the coal coke is fully impregnated to make the catalyst loading reach 10% of the mass of the coal coke; the coal coke loaded with calcium oxide is dried at 105 degrees Celsius for 12 hours, and is stored in a sealed state for standby use;

[0053] Step 2: Preparation of high-pressure gasification reaction system

[0054] A high-pressure thermogravimetric analyzer or a custom high-pressure fixed bed reactor system is used, the system needs to include a precision temperature control device, a multi-channel gas mixing module, a high-precision pressure sensor, and a real-time gas component analyzer; the gas flow controller is calibrated to ensure that the flow error is less than 1%;

[0055] A water vapor generating device is configured, liquid water is delivered to a high-temperature vaporizer by a precision syringe pump, and is input into the reactor through a preheating pipeline to avoid steam condensation;

[0056] Step three: Set the gas diffusion conditions

[0057] Design variable diffusion intensity experiment group: by adjusting the total pressure of the system, gas linear velocity and coal pore structure combination, simulate the diffusion environment of industrial gasifier; According to Fick's diffusion law, the thickness of gas phase boundary layer is calculated, and the quantitative relationship formula of diffusion resistance is established for subsequent dynamic correction;

[0058] Step four: gasification reaction kinetics experiment

[0059] Take 300 milligrams of calcium oxide loaded coal sample and lay it in the high-pressure reactor quartz crucible, blow in 50 milliliters of high-purity nitrogen per minute for 20 minutes, heat up to the preset temperature at 15 degrees Celsius per minute, and maintain the system pressure to the target value after constant temperature stabilization;

[0060] Switch to the target reaction atmosphere:

[0061] Carbon dioxide atmosphere: volume fraction 100% carbon dioxide, total flow 100 milliliters per minute;

[0062] Steam atmosphere: nitrogen carrier gas mixed with steam, steam saturation degree monitored by dew point sensor;

[0063] Oxygen atmosphere: 5% oxygen and 95% carbon dioxide mixed gas to simulate partial oxidation;

[0064] Record the sample mass change in real time through thermogravimetric signal, simultaneously collect the outlet gas composition, analyze the carbon monoxide, hydrogen and carbon dioxide concentration through gas chromatography; Each condition is repeated at least three times, until the sample mass change rate meets the requirements to determine the reaction termination;

[0065] Step five: data acquisition and processing

[0066] Calculate the carbon conversion rate according to the weight loss curve:

[0067]

[0068] Where m0 is the initial mass, m t is the mass at time t, m ∞ is the ash mass;

[0069] Extract the reaction rate at different conversion rates:

[0070]

[0071] Where, dX is the increment of carbon conversion rate in a very short time dt; dt is the minimum sampling interval of experimental data; k is the pre-exponential factor; n is the reaction order; f(P g ) is the gas partial pressure function; T is the thermodynamic temperature of the reaction system; R is the ideal gas constant; Ea is the apparent activation energy;

[0072] The apparent activation energy and pre-exponential factor were calculated using the Arrhenius curve, and the differences in kinetic parameters under different atmospheres were compared.

[0073] Step 6: Analysis of catalyst effect and diffusion contribution

[0074] Carry out blank control experiment: Test the gasification kinetics of coal char without calcium oxide under the same conditions and calculate the calcium oxide catalytic efficiency factor Quantitative evaluation of gas diffusion effects based on Weber number:

[0075]

[0076] Among them, D e is the effective diffusion coefficient; δ is the boundary thickness; k s is the intrinsic reaction rate constant; C g is the concentration of gas-phase reactants in the mainstream region of the reactor; n is the reaction order of the gas-phase reactants;

[0077] Draw a catalytic-diffusion synergistic phase diagram to define the reaction-controlled region, diffusion-controlled region, and transition region;

[0078] Step 7: Experimental quality control

[0079] Each batch of coal char samples undergoes industrial analysis to determine the fixed carbon, volatile matter, and ash content. The specific surface area is determined by the nitrogen adsorption BET method, taking the average of three samples. The calcium oxide dispersion is characterized by scanning electron microscopy combined with energy spectrum analysis. Gas calibration is performed using a standard gas calibration analyzer, with detection limits for carbon dioxide, hydrogen, and carbon monoxide below 5 parts per million.

[0080] Data validity determination: The carbon conversion rate deviation of repeated experiments under the same conditions shall not exceed plus or minus 3%, otherwise the experiment shall be repeated;

[0081] Residue mineral analysis: X-ray diffraction analysis of the samples after reaction was used to identify the catalyst phase change.

[0082] First, coal char of a specific particle size was prepared and precisely loaded with a calcium oxide catalyst. Secondly, a reaction system integrating high-pressure thermogravimetry and online gas analysis was built, and the multi-channel atmosphere supply module was calibrated. Subsequently, the gas diffusion conditions were set by adjusting the total pressure, gas velocity, and pore structure. A multi-atmosphere gasification experiment was carried out in a high-pressure reactor, and weight loss and gas composition data were collected in real time. The reaction rate was then extracted based on the carbon conversion rate, and the kinetic parameters were solved using the Arrhenius equation. The Weber number model was used to quantitatively separate the catalyst activity and diffusion effect. Finally, quality control of the entire process was achieved through industrial analysis, gas calibration, and residue phase change identification.

[0083] In the process of adding coal char for impregnation in step 1, a dynamic adsorption-equilibrium filtration method is adopted, and the coal char is placed in a constant temperature 30° C. suspension and ultrasonically vibrated for 30 minutes, followed by centrifugation at 2000 revolutions per minute for 60 seconds.

[0084] The dynamic adsorption-equilibrium filtration method is used to improve the dispersion uniformity of the calcium oxide catalyst, and the physical field enhancement method is used to enable the active components to penetrate deeply into the pores of the coal coke, while avoiding mass transfer blockage caused by excessive attachment.

[0085] In step 1, the dipping container is limited to be made of polytetrafluoroethylene to avoid metal ion contamination.

[0086] By using a container made of polytetrafluoroethylene, the risk of metal ion migration is eliminated and the chemical purity of the catalytic system is maintained.

[0087] In the water vapor atmosphere experiment in step 4, the dew point sensor needs to record the steam saturation every 10 minutes. When the saturation is lower than 95%, the experiment should be immediately suspended to check the vaporization device.

[0088] By monitoring in 10-minute cycles, steam supply anomalies can be detected in a timely manner and precise control of gas-phase reactant concentrations can be maintained.

[0089] Among them, the termination of the reaction in step 4 requires the simultaneous satisfaction of two conditions: the sample mass change rate is less than one thousandth per minute for three consecutive minutes, and the fluctuation range of the outlet carbon monoxide concentration is less than 1%.

[0090] The dual-criteria design forms a complementary verification mechanism, which not only overcomes the false termination misjudgment caused by instrument noise, but also avoids the signal distortion caused by the diffusion lag of the product in the late stage of the reaction, and accurately captures the critical point where the reaction completely stops.

[0091] Among them, the blank control group experiment in step 6 must be carried out simultaneously with each group of catalytic experiments, and the ash composition of the blank sample must be completely consistent with that of the catalytic sample.

[0092] Maintaining ash consistency can eliminate the interference of coal char's own minerals on the catalytic effect, so that the activity difference between the blank group and the catalytic group can be completely attributed to the effect of the loaded catalyst.

[0093] Among them, the maximum pressure of the high-pressure reactor in step 4 shall not exceed 80% of the rated pressure of the equipment during the experiment, and the oxygen partial pressure is strictly limited to below 0.5 MPa to prevent the risk of explosion.

[0094] By limiting the pressure value, safety during the experiment is ensured.

[0095] The X-ray diffraction analysis of the residue mineral in step seven needs to be completed within two hours after the reaction ends to avoid phase change of intermediate products such as calcium carbonate due to air contact.

[0096] By limiting the X-ray diffraction analysis time, chemical conversion of air-sensitive substances is prevented.

[0097] In step two, the high-pressure gasification reaction system preparation includes airtightness test of the high-pressure reactor, filling 3 MPa nitrogen for pressure maintaining for 30 minutes, and the pressure drop is not more than 5 parts per thousand.

[0098] The airtightness test of the high-pressure reactor avoids the deviation of atmosphere components caused by trace leakage.

[0099] It should be noted that, in this document, the terms such as first and second are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed, or inherent to such a process, method, article or apparatus.

[0100] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification reaction under different atmospheres, characterized in that: The specific steps are as follows: Step 1: Preparation and pretreatment of experimental raw materials Representative coal types were selected and crushed and screened to obtain pulverized coal samples with a particle size range of 75 to 150 microns. The pulverized coal was placed in a high-purity nitrogen tubular furnace and heated at a rate of 10 degrees Celsius per minute to 900 degrees Celsius. The temperature was maintained at this temperature for 30 minutes to produce high-temperature coal char. Calcium oxide catalyst powder was mixed with deionized water in a mass ratio of 1:5 and stirred for 60 minutes to form a suspension. Coal char was added and fully impregnated to ensure that the catalyst loading reached 10% of the coal char mass. The calcium oxide-loaded coal char sample was dried at 105 degrees Celsius for 12 hours and sealed for storage. Step 2: Preparation of high-pressure gasification reaction system Use a high-pressure thermogravimetric analyzer or a customized high-pressure fixed-bed reactor system. The system must include a precision temperature control device, a multi-channel gas mixing module, a high-precision pressure sensor, and a real-time gas composition analyzer. Calibrate the gas flow controller to ensure that the flow error is less than 1%. Equipped with a steam generator, liquid water is delivered to the high-temperature vaporizer through a precision injection pump and then fed into the reactor through a preheating pipeline to avoid steam condensation; Step 3: Set gas diffusion conditions Design a variable diffusion intensity experiment: By adjusting the system total pressure, gas linear velocity, and coal char pore structure, the diffusion environment of an industrial gasifier is simulated. The gas boundary layer thickness is calculated according to Fick's diffusion law, and a quantitative relationship for diffusion resistance is established for subsequent dynamic correction. Step 4: Gasification reaction kinetics experiment A 300 mg sample of calcium oxide-loaded coal char was placed flat in a quartz crucible in a high-pressure reactor. A high-purity nitrogen gas flow rate of 50 ml / min was introduced for 20 minutes. The temperature was then raised at 15°C / min to a preset temperature. After the temperature stabilized, the system pressure was maintained at the target value. Switch to target reaction atmosphere: Carbon dioxide atmosphere: 100% carbon dioxide by volume, with a total flow rate of 100 ml per minute; Water vapor atmosphere: nitrogen carrier gas is introduced to mix with water vapor, and the steam saturation is monitored by a dew point sensor; Oxygen atmosphere: A mixture of 5% oxygen and 95% carbon dioxide by volume was introduced to simulate partial oxidation; The sample mass change is recorded in real time through thermogravimetric signals, and the outlet gas composition is collected simultaneously. The concentrations of carbon monoxide, hydrogen, and carbon dioxide are analyzed by gas chromatography. The experiment is repeated at least three times for each condition until the sample mass change rate meets the requirements and the reaction is determined to be terminated. Step 5: Data collection and processing Calculate the carbon conversion rate based on the weight loss curve: Where m0 is the initial mass, m t is the mass at time t, m ∞ is the ash mass; Extract reaction rates at different conversion rates: Where dX is the increment of carbon conversion rate in a very short time dt; dt is the minimum sampling interval of experimental data sampling time; k is the pre-exponential factor; n is the reaction order; f(P g ) is the gas partial pressure function; T is the thermodynamic temperature of the reaction system; R is the ideal gas constant; E a is the apparent activation energy; The apparent activation energy and pre-exponential factor were calculated using the Arrhenius curve, and the differences in kinetic parameters under different atmospheres were compared. Step 6: Analysis of catalyst effect and diffusion contribution Carry out blank control experiment: Test the gasification kinetics of coal char without calcium oxide under the same conditions and calculate the calcium oxide catalytic efficiency factor Quantitative evaluation of gas diffusion effects based on Weber number: Among them, D e is the effective diffusion coefficient; δ is the boundary thickness; k s is the intrinsic reaction rate constant; C g is the concentration of gas-phase reactants in the mainstream region of the reactor; n is the reaction order of the gas-phase reactants; Draw a catalytic-diffusion synergistic phase diagram to define the reaction-controlled region, diffusion-controlled region, and transition region; Step 7: Experimental quality control Each batch of coal char samples undergoes industrial analysis to determine the fixed carbon, volatile matter, and ash content. The specific surface area is determined by the nitrogen adsorption BET method, taking the average of three samples. The calcium oxide dispersion is characterized by scanning electron microscopy combined with energy spectrum analysis. Gas calibration is performed using a standard gas calibration analyzer, with detection limits for carbon dioxide, hydrogen, and carbon monoxide below 5 parts per million. Data validity determination: The carbon conversion rate deviation of repeated experiments under the same conditions shall not exceed plus or minus 3%, otherwise the experiment shall be repeated; Residue mineral analysis: X-ray diffraction analysis of the samples after reaction was used to identify the catalyst phase change.

2. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: During the impregnation process of adding coal char in step 1, the dynamic adsorption-equilibrium filtration method is adopted, and the coal char is placed in a constant temperature 30° C. suspension and ultrasonically shaken for 30 minutes, followed by centrifugation at 2000 revolutions per minute for 60 seconds.

3. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The immersion container in step 1 is limited to polytetrafluoroethylene to avoid metal ion contamination.

4. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: In the water vapor atmosphere experiment described in step 4, the dew point sensor needs to record the steam saturation every 10 minutes. When the saturation is lower than 95%, the experiment should be immediately suspended to check the vaporization device.

5. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The termination of the reaction in step 4 requires that two conditions are met simultaneously: the sample mass change rate is less than one thousandth per minute for three consecutive minutes, and the fluctuation range of the outlet carbon monoxide concentration is less than 1%.

6. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The blank control group experiment described in step 6 must be carried out simultaneously with each catalytic experiment, and the ash composition of the blank sample must be completely consistent with that of the catalytic sample.

7. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The maximum pressure of the high-pressure reactor described in step 4 during the experiment shall not exceed 80% of the rated pressure of the equipment, and the oxygen partial pressure is strictly limited to below 0.5 MPa to prevent the risk of explosion.

8. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The X-ray diffraction analysis of the residual mineral analysis in step 7 must be completed within two hours after the end of the reaction to avoid phase changes of intermediate products such as calcium carbonate due to contact with air.

9. The experimental method for CaO-catalyzed high-temperature coal char high-pressure gasification under different atmospheres according to claim 1, characterized in that: The preparation of the high-pressure gasification reaction system in step 2 includes performing an airtightness test on the high-pressure reactor, filling it with 3 MPa nitrogen and maintaining the pressure for 30 minutes, and the pressure drop is no more than 0.5%.

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