Preparation method of peanut shell biomass and adsorption method of peanut shell biomass for treating SO2 and VOCs
By preparing and treating biochar at different temperatures by peanut shell biomass, the management problems of VOCs and SO2 in coal-fired emissions are solved, efficient adsorption and removal of these pollutants are achieved, and the efficiency of pollutants is significantly improved.
Patent Information
- Application Number
- CN202411949821.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-06-24
AI Technical Summary
The prior art is difficult to effectively control volatile organic compounds (VOCs) and sulfur dioxide (SO2) in coal-fired emissions, which pose a threat to ecosystems and human health.
Peanut shell biomass was used to prepare biochar, and the peanut shell biochar was prepared at different temperatures by treating oxygen-limited pyrolysis method and nitrogen pyrolysis method.
The adsorption of SO2 and VOCs was achieved efficiently, especially the adsorption of SO2 by PSN700 reached 24.83 mg·g-1, and the adsorption of PSA600 toluene reached 50.58 mg·g-1, significantly improving the pollutant removal efficiency.
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Figure CN120189909A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of adsorption, and specifically relates to a preparation of peanut shell biomass and an adsorption method for treating VOCs and SO2. Background Art
[0002] Coal accounts for more than half of the energy consumption. Past research has shown that outdoor air pollutants cause more than 3 million premature deaths globally every year. If countries around the world do not implement strict governance policies, the number of deaths caused by outdoor air pollution will rise to nearly 7 million annually by 2050. The air pollutants emitted from coal combustion account for the main part of outdoor air pollutants, among which sulfur dioxide emitted from coal combustion accounts for 87% and nitrogen oxides account for 67%. In addition, a large amount of volatile organic compounds (VOCs) are also one of the gaseous pollutants emitted during the coal combustion process. The presence of a large amount of volatile organic compounds and sulfur dioxide not only harms the ecosystem, but also poses a threat to human well-being due to their high volatility at ambient temperature.
[0003] In addition to adsorbing sulfur dioxide, biochar also has good adsorption capacity for VOCs and has received a lot of research basis in recent years. However, there are not many studies on the co-combustion of biomass and VOCs. In terms of biochar, past research has mainly been applied to the adsorption of pollutants in water and the improvement of pollutants in soil, and there are not many studies on air pollutants, especially the treatment of VOCs and SO2 coal combustion pollutants. Summary of the Invention
[0004] In view of the current environmental problems, especially the pollution control of VOCs and SO2, an efficient adsorbent is needed.
[0005] In view of the problems existing in the prior art, the present invention proposes a preparation of peanut shell biomass and an adsorption method for treating VOCs and SO2.
[0006] An adsorption method for treating VOCs and SO2 with peanut shell biomass includes the following steps:
[0007] (1) The preparation scheme of peanut shell biochar includes the following steps:
[0008] ① Cleaning and drying: Wash the peanut shells 4 times with deionized water to remove impurities such as dust on the surface of the peanut shells; dry the washed peanut shells, the drying temperature is 80 °C, and the drying time is 12 h.
[0009] ② Grinding and sieving: Put the washed and dried peanut shells into a high-speed crusher for crushing, the rotation speed is 25000 rpm, and the crushing time is 2 min; the crushed peanut shell powder is respectively sieved through 10-mesh, 24-mesh and 50-mesh pharmacopoeia sieves to divide the powder into three different particle sizes.
[0010] ③Aluminum foil limited oxygen pyrolysis method: Place the peanut shell powder in a crucible, fill the crucible and compact it with a spatula. Then wrap the crucible with tin foil three times to isolate the air and achieve the purpose of limited oxygen. Place the wrapped crucible in a mixing furnace and pyrolyze it at a set temperature. After waiting for the mixing furnace to cool to room temperature, take out the sample and store it in a desiccator.
[0011] ④Nitrogen pyrolysis method: Put the peanut shell powder into a quartz boat and place it in a mixing furnace. Before pyrolysis, exhaust the air and introduce nitrogen to create a nitrogen atmosphere. Continuously introduce nitrogen as a protective gas during the pyrolysis process, with a flow rate of 100 mL min -1 , pyrolyze at a set temperature. After waiting for the mixing furnace to cool to room temperature, turn off the nitrogen, take out the sample and store it in a desiccator.
[0012] According to the above scheme, the two pyrolysis methods are pyrolyzed at temperatures of 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C and 600 °C.
[0013] According to the above scheme, the heating rate is 10 °C·min -1 , and keep it at a constant temperature for 180 min after reaching the set temperature.
[0014] According to the above scheme, record the mass of the sample before and after pyrolysis carbonization. The biochars prepared by the aluminum foil limited oxygen pyrolysis method at different temperatures are denoted as PSA300, PSA350, PSA400, PSA450, PSA500, PSA550, PSA600 respectively; the biochars prepared by the nitrogen pyrolysis method at different temperatures are denoted as PSN300, PSN350, PSN400, PSN450, PSN500, PSN550, PSN600, PSN650, PSN700 respectively.
[0015] The method for treating and adsorbing SO2 and VOCs with the peanut shell biomass obtained in the above step (1) includes the following steps:
[0016] ①The biochar is well fixed in a quartz tube, and the constant temperature is controlled by a vertical tube furnace to ensure that the adsorption temperature remains unchanged during the adsorption process.
[0017] ②Respectively control high-purity nitrogen and the standard gas to be treated through a gas mass flowmeter to obtain a mixed gas with a certain concentration.
[0018] ③After detecting that the gas concentration is stable with an analyzer, introduce it into the biochar adsorption unit.
[0019] According to the above scheme, the concentration of the mixed gas obtained through the gas mass flowmeter is 1111111 ppm.
[0020] According to the above scheme, weigh 60 mg of biochar for each adsorption.
[0021] According to the above scheme, the temperature of the vertical tube furnace is controlled to be a constant 111111 °C.
[0022] According to the above scheme, the adsorption inlet gas volume is 200 mL·min -1 .
[0023] According to the above scheme, when the gas concentrations at the inlet and outlet are the same, it is regarded that the biochar has reached adsorption saturation. Description of the Drawings
[0024] Figure 1 It is the infrared spectrum diagram of biochar.
[0025] Figure 2 It is the XRD diagram of the biochar sample.
[0026] Figure 3 It is the scanning electron microscope diagram of biochar.
[0027] Figure 4 It is the adsorption kinetic curve diagram of SO2 on biochar.
[0028] Figure 5 It is the adsorption amount of each adsorbent at the adsorption equilibrium of SO2.
[0029] Figure 6 It is the adsorption kinetic curve diagram of toluene on biochar.
[0030] Figure 7 It is the adsorption amount of each adsorbent at the adsorption equilibrium of toluene. Detailed Implementation Modes
[0031] The following are specific embodiments of the present invention, which clearly and completely describe the technical solutions of the present invention. The experimental methods in the following embodiments are all conventional methods unless otherwise specified.
[0032] The technical solution of the present invention is as follows:
[0033] The preparation schemes of two different pyrolysis methods of peanut shell biochar include the following steps:
[0034] (1) Wash the peanut shells 4 times with deionized water to remove impurities such as dust on the surface of the peanut shells; dry the washed peanut shells, the drying temperature is 80 °C, and the drying time is 12 h.
[0035] (2) Put the washed and dried peanut shells into a high-speed crusher for crushing, the rotation speed is 25000 rpm, and the crushing time is 2 min; the crushed peanut shell powder is respectively passed through 10-mesh, 24-mesh and 50-mesh pharmacopoeia sieves to divide the powder into three different particle sizes.
[0036] (3) Aluminum foil limited oxygen pyrolysis method: Place the peanut shell powder in a crucible, fill the crucible and compact it with a spatula. Then wrap the crucible with tin foil three times to isolate air and achieve the purpose of limited oxygen. Put the wrapped crucible into a mixing furnace and pyrolyze it at the set temperature. After waiting for the mixing furnace to cool down to room temperature, take out the sample and store it in a desiccator.
[0037] (4) Nitrogen pyrolysis method: Put the peanut shell powder into a quartz boat and place it in a mixing furnace. Before pyrolysis, evacuate the air and introduce nitrogen to create a nitrogen atmosphere. Continuously introduce nitrogen as a protective gas during pyrolysis, with a flow rate of 100 mL / min -1 , pyrolyze it at the set temperature. After waiting for the mixing furnace to cool down to room temperature, turn off the nitrogen and take out the sample and store it in a desiccator.
[0038] Further, the two pyrolysis methods are pyrolyzed at temperatures of 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C and 600 °C.
[0039] Further, the heating rate is 10 °C·min -1 , and keep it at a constant temperature for 180 min after reaching the set temperature.
[0040] Further, record the mass of the sample before and after pyrolysis carbonization. The ratio of the mass of the biochar after pyrolysis to the mass of the biomass raw material is the biochar yield. The biochars prepared by the aluminum foil limited oxygen pyrolysis method at different temperatures are respectively denoted as PSA300, PSA350, PSA400, PSA450, PSA500, PSA550, PSA600; the biochars prepared by the nitrogen pyrolysis method at different temperatures are respectively denoted as PSN300, PSN350, PSN400, PSN450, PSN500, PSN550, PSN600, PSN650, PSN700.
[0041] The embodiment of the present invention provides a method for using the peanut shell biochar prepared in the above steps (3) and (4) to adsorb SO2 and VOCs: The biochar is well fixed in a quartz tube, and the vertical tube furnace controls a constant temperature to ensure that the adsorption temperature remains unchanged during the adsorption process; respectively control high-purity nitrogen and the standard gas to be treated through a gas mass flowmeter to obtain a mixed gas with a certain concentration; use an analyzer to detect the gas concentration and then introduce it into the biochar adsorption unit. When the gas concentrations at the inlet and outlet are the same, it is considered that the biochar has reached adsorption saturation.
[0042] Further, the concentration of the mixed gas obtained through the gas mass flowmeter is 1111111 ppm.
[0043] Further, each time 60 mg of biochar is weighed for adsorption.
[0044] Further, the vertical tube furnace is controlled to maintain a constant temperature of 111111 °C.
[0045] Further, the adsorption inlet gas volume is 200 mL·min -1 .
[0046] Further, when the gas concentrations at the inlet and outlet are the same, it is considered that the biochar has reached adsorption saturation.
[0047] Implementation Case 1
[0048] Preparation schemes of peanut shell biochar by two different pyrolysis methods, including the following steps: Before pyrolysis, first wash the peanut shells 4 times with deionized water to remove impurities such as dust on the surface of the peanut shells, and then put them into an oven and bake at 80 °C for 12 hours; put the washed and dried peanut shells into a high-speed crusher and crush them into fine powder at a speed of 25000 rpm for two minutes. The crushed peanut shell powder is respectively sieved through 10-mesh, 24-mesh and 50-mesh pharmacopoeia sieves to divide the powder into three different particle sizes; Aluminum foil oxygen-limited pyrolysis method: Place the peanut shell powder in a crucible, fill the crucible and compact it with a spatula, and then wrap the crucible with tin foil three layers to isolate the air to achieve the purpose of oxygen limitation. Put the wrapped crucible into a mixing furnace and carry out pyrolysis at a temperature of 300 - 650 °C (heating rate is 10 °C·min -1 , after reaching a temperature of 300 °C, keep it at a constant temperature for 180 min), wait for the mixing furnace to cool down to room temperature, then take out the sample and put it into a desiccator for storage; Nitrogen pyrolysis method: Put the peanut shell powder into a quartz boat and place it in a mixing furnace. Before pyrolysis, discharge the air and pass nitrogen to create a nitrogen atmosphere. During the pyrolysis process, continuously pass nitrogen as a protective gas, and the flow rate is 100 mL min -1 , put the wrapped crucible into a mixing furnace and carry out pyrolysis at a temperature of 300 - 650 °C (heating rate is 10 °C·min -1 , after reaching a temperature of 300 °C, keep it at a constant temperature for 180 min), wait for the mixing furnace to cool down to room temperature, then turn off the nitrogen and take out the sample and put it into a desiccator for storage. The infrared spectra, X-ray diffraction and microscopic morphology photos of the peanut shell biochar obtained by the two pyrolysis methods are as shown in Figure 1 , Figure 2 and Figure 3 shown
[0049] Using the above-prepared peanut shell biochar for SO2 adsorption treatment, including the following steps: For the adsorption of SO2, the high-purity nitrogen and SO2 standard gas are respectively controlled by a gas mass flowmeter so that the concentration of the mixed gas is 2500 ppm (6550.51 mg·m -3 ), after detecting that the gas concentration is stable with a flue gas analyzer, introduce it into the biochar adsorption unit. The vertical tube furnace is controlled to maintain a constant temperature of 50 °C. Each time for the adsorption experiment, weigh 60 mg of biochar, and the inlet gas volume for the adsorption experiment is 200 mL·min-1 When the gas concentrations at the inlet and outlet are the same, it is considered that the biochar has reached adsorption saturation. The adsorption kinetic curve of biochar for SO2 and the adsorption capacity of each adsorbent at adsorption equilibrium are shown in Figure 4 and Figure 5 as follows. The adsorption amounts of different biochar materials for SO2 at the end of the 120-min adsorption experiment are concentrated between 1.58 - 24.83 mg·g -1 , among which the adsorption amount of PSN700 for SO2 reaches 24.83 mg·g -1 .
[0050] Example 2
[0051] Preparation schemes of peanut shell biochar by two different pyrolysis methods, including the following steps: Before pyrolysis, first wash the peanut shells 4 times with deionized water to remove impurities such as dust on the surface of the peanut shells, and then put them into an oven and bake at 80 °C for 12 hours; put the washed and dried peanut shells into a high-speed crusher and crush them into fine powder at a speed of 25,000 rpm for two minutes. The crushed peanut shell powder is respectively sieved through 10-mesh, 24-mesh, and 50-mesh pharmacopoeia sieves to divide the powder into three different particle sizes; Aluminum foil oxygen-limited pyrolysis method: Place the peanut shell powder in a crucible, fill the crucible and compact it with a spatula, and then wrap the crucible with tin foil three layers to isolate the air to achieve the purpose of oxygen limitation. Put the wrapped crucible into a mixing furnace and pyrolyze at a temperature of 300 - 650 °C (heating rate is 10 °C·min -1 , after reaching a temperature of 400 °C, keep it at a constant temperature for 180 min), wait for the mixing furnace to cool to room temperature, then take out the sample and put it into a desiccator for storage; Nitrogen pyrolysis method: Put the peanut shell powder into a quartz boat and place it in a mixing furnace. Before pyrolysis, discharge the air and pass nitrogen to create a nitrogen atmosphere. During the pyrolysis process, continuously pass nitrogen as a protective gas, with a flow rate of 100 mL min -1 , put the wrapped crucible into a mixing furnace and pyrolyze at a temperature of 300 - 650 °C (heating rate is 10 °C·min -1 , after reaching a temperature of 400 °C, keep it at a constant temperature for 180 min), wait for the mixing furnace to cool to room temperature, then turn off the nitrogen and take out the sample and put it into a desiccator for storage.
[0052] Use the peanut shell biochar prepared above for VOCs adsorption treatment, including the following steps: For the adsorption of toluene, control high-purity nitrogen and 3000 ppm toluene standard gas respectively through a gas mass flowmeter, so that the concentration of the mixed gas is 150 ppm (565.28 mg·m -3 ), after detecting that the gas concentration is stable with a portable volatile organic gas analyzer, introduce it into the biochar adsorption unit. The vertical tube furnace controls the temperature to be constant at 30 °C. Each time during the adsorption experiment, weigh 60 mg of biochar, and the intake air volume of the adsorption experiment is 200 mL·min -1When the gas concentrations at the inlet and outlet are the same, it is considered that the biochar has reached adsorption saturation. The adsorption kinetic curve of toluene by biochar and the adsorption capacity of each adsorbent at adsorption equilibrium are shown in Figure 6 and Figure 7 As shown. The toluene adsorption amounts of different biochar materials are concentrated between 13 - 51 mg·g -1 , among which the toluene adsorption amount of PSA600 reaches 50.58 mg·g -1 .
Claims
1. Preparation of peanut shell biomass and its adsorption method for treating VOCs, Its characteristics include the following steps: (1) A method for preparing peanut shell biochar comprises the following steps: ① Cleaning and drying: Wash the peanut shells 4 times with deionized water to remove dust and other impurities on the surface of the peanut shells; dry the washed peanut shells at 80°C for 12 hours; ② Grinding and sieving: Put the washed and dried peanut shells into a high-speed grinder for grinding at a speed of 25,000 rpm for 2 minutes; the ground peanut shell powder is passed through a 10-50 mesh pharmacopoeia sieve to separate the powder into three different particle sizes; ③ Aluminum foil oxygen-limited pyrolysis method: Place peanut shell powder in a crucible, fill the crucible and compact it with a medicine spoon, then wrap the crucible with three layers of tin foil to isolate the air to achieve the purpose of oxygen limitation. Place the wrapped crucible in a mixing furnace and perform pyrolysis at the set temperature. After the mixing furnace cools to room temperature, take out the sample and store it in a desiccator; ④ Nitrogen pyrolysis method: peanut shell powder is placed in a quartz boat in a mixing furnace. Before pyrolysis, nitrogen is passed through the exhaust air to create a nitrogen atmosphere. During the pyrolysis process, nitrogen is continuously passed through as a protective gas at a flow rate of 100 mL min -1 , perform pyrolysis at the set temperature, wait for the mixing furnace to cool to room temperature, turn off the nitrogen, take out the sample and store it in a desiccator. (2) A method for treating the prepared peanut shell biomass to adsorb SO2 and VOCs, which comprises the following steps: ① The biochar is well fixed in the quartz tube, and the vertical tube furnace controls the constant temperature to ensure that the adsorption temperature remains unchanged during the adsorption process; ② The high-purity nitrogen and the standard gas to be processed are controlled separately by the gas mass flow meter to obtain a mixed gas of a certain concentration; ③ Use an analyzer to detect the gas concentration and then pass it into the biochar adsorption unit. When the gas concentrations at the inlet and outlet are consistent, the biochar is considered to have reached adsorption saturation.
2. The method for preparing peanut shell biochar according to claim 1, characterized in that The two pyrolysis methods in steps ③ and ④ are carried out at temperatures of 300°C, 350°C, 400°C, 450°C, 500°C, 550°C and 600°C.
3. The method for preparing peanut shell biochar according to claim 1, characterized in that The heating rate of the two pyrolysis methods in steps ③ and ④ is 10℃·min -1 , and keep the temperature constant for 180 minutes after reaching the set temperature.
4. The method for adsorbing SO2 and VOCs by peanut shell biochar according to claim 1, characterized in that The mixed gas concentration obtained by the gas mass flow meter is 100 ppm to 3000 ppm.
5. The method for adsorbing SO2 and VOCs by peanut shell biochar according to claim 1, characterized in that For each adsorption experiment, 60 mg of biochar was weighed.
6. The method for adsorbing SO2 and VOCs by peanut shell biochar according to claim 1, characterized in that The vertical tube furnace is controlled to have a constant temperature of 20°C to 60°C.
7. The method for adsorbing SO2 and VOCs by peanut shell biochar according to claim 1, characterized in that The air intake volume for the adsorption experiment was 200 mL min -1 .
8. The method for preparing peanut shells according to claims 1-4, characterized in that Application of the prepared peanut shell biochar in the fields of SO2 and VOCs.