Preparation method of porous silicon-based molecular sieve for CO2 capture and hydrothermal reactor

Abstract

The present invention discloses a preparation method and a hydrothermal reactor for porous silicon-based molecular sieves for CO2 capture, and belongs to the technical field of mosquito traps. The preparation method comprises: placing an organosilicon source, a template, water and a high-boiling-point alcohol into a closed hydrothermal reactor, and causing the mixture in the hydrothermal reactor to periodically rotate forward and reverse during the heating and insulation process; gradually increasing the temperature in the hydrothermal reactor, gradually increasing the speed of the mixture periodically rotating forward and reverse, and gradually extending the pause interval; centrifuging the precipitate, and drying it; and roasting it. The hydrothermal reactor comprises a reactor body, an outer shell, a motor and a controller. The present invention uses a specially designed hydrothermal reactor to avoid the risk of gas leakage in traditional mechanical stirring and maintain a precise temperature and pressure in the hydrothermal reactor; at the same time, an appropriate amount of high-boiling-point alcohol is introduced and the periodic forward and reverse rotation is controlled to regulate the hydrothermal crystallization process, thereby obtaining a silicon-based molecular sieve with a high specific surface area and a large pore size.

Description

Technical Field

[0001] The present invention relates to the technical field of mosquito traps, and in particular to a preparation method of a porous silicon-based molecular sieve for CO2 capture and a hydrothermal reactor. Background Art

[0002] Mosquitoes are carriers of numerous pathogens, capable of transmitting over 80 diseases and posing a serious threat to human health. Currently, existing mosquito trapping technologies include UV light trapping, human odor-mimicking trapping, and the use of CO2 as an attractant. Among these, CO2 as an attractant is a recent research hotspot due to its environmental friendliness, high efficiency, and safety.

[0003] The technology of using CO2 as an attractant mainly considers that mosquitoes often determine their targets by identifying the source of carbon dioxide. By setting up a mosquito trapping device, a capture material adsorbed with carbon dioxide is placed in the mosquito trapping device, and mosquitoes are attracted by releasing carbon dioxide. This trapping method does not require the release or diffusion of chemicals into the environment, nor does it require application to the human body, and it can kill mosquitoes within a certain range.

[0004] For example, a Chinese invention (titled "A mosquito attractant composition using chitosan as a carrier to bind pyruvic acid for CO2 absorption, its preparation method, and use," Publication No. CN114375954B, Publication Date: June 23, 2023) discloses a mosquito attractant composition using chitosan as a carrier to bind pyruvic acid for CO2 absorption, its preparation method, and use. The composition is a gel-like mosquito attractant obtained by binding pyruvic acid with chitosan as a carrier to absorb CO2, with the CO2 added in solid form. The proposed mosquito attractant composition, through the synergistic effect of its components, simulates human odor, and can absorb and slowly release CO2, effectively trapping both Aedes albopictus and Culex pipiens quinquefasciatus. However, the CO2 in this prior art is added in solid form, making it a disposable consumable, inconvenient to use, and unable to release CO2 continuously and stably.

[0005] For example, a Chinese invention (titled "Synthesis of SSZ-16 Zeolite Molecular Sieve from Solid Waste and Its Adsorption Separation Application," publication number: CN117326568A, publication date: January 2, 2024) discloses: mixing water, an alkali source, an organic template, a silicon source, and FCC solid waste to obtain an initial reaction gel; hydrothermally crystallizing the initial reaction gel to obtain an initial SSZ16 zeolite molecular sieve; and calcining the initial SSZ16 zeolite molecular sieve to obtain an SSZ16 zeolite molecular sieve with excellent carbon dioxide selective adsorption and separation performance. The hydrothermal crystallization process is typically carried out in a closed environment with stirring. However, existing hydrothermal reactors typically use mechanical stirring, which places high demands on the sealing of the mechanical stirring. Summary of the Invention

[0006] The present invention aims to provide a preparation method and a hydrothermal reactor for porous silicon-based molecular sieves for CO2 capture. A hydrothermal reactor without a mechanical stirring structure directly driven by a motor is used as the main synthesis structure, which can avoid the risk of gas leakage in traditional mechanical stirring and maintain precise temperature and pressure in the hydrothermal reactor. At the same time, an appropriate amount of high-boiling-point alcohol is introduced into the preparation of the silicon-based molecular sieve to regulate the hydrolysis process of the organic silicon source, control the hydrothermal reaction rate, improve uniformity and stability, regulate the pore characteristics of the precipitate and affect the particle size of the precipitate. Finally, during the hydrothermal reaction process, forward and reverse rotation is performed periodically, and the rotation speed of each cycle is different, and the pause interval time is also different. The early stage of the hydrothermal reaction is a dynamic process, and the grains are small and uniform. The later stage is a static process, and the grains gradually increase. Finally, a silicon-based molecular sieve with a high specific surface area and a large pore size is obtained, which has a good adsorption effect on carbon dioxide.

[0007] The technical solution adopted in the present invention is:

[0008] A method for preparing a porous silicon-based molecular sieve for CO2 capture comprises the following steps: Step S1, charging an organic silicon source, a template, water, and a high-boiling-point alcohol into a closed hydrothermal reactor without a mechanical stirring structure directly driven by a motor in a mass ratio of 1:0.1-0.5:20:0.15, gradually raising the temperature in the hydrothermal reactor to 40-50°C by radiation heat transfer, and then maintaining the temperature for 1-2 hours; simultaneously, during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the rotation speed during forward and reverse rotation is 100-150 rpm; the forward and reverse rotations in the same cycle last for 5-10 minutes respectively, and the pause interval between forward and reverse rotations in the same cycle is 0-5 seconds; the pause interval between reverse rotation in the previous cycle and forward rotation in the next cycle is 5-30 minutes;

[0009] Step S2: gradually raising the temperature in the hydrothermal reactor to 80-100° C. by radiation heat transfer, and then maintaining the temperature for 12-24 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 50-100 rpm; the forward and reverse rotations in the same cycle last for 3-5 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 30-60 seconds; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 1-2 hours;

[0010] Step S3, gradually raising the temperature in the hydrothermal reactor to 120-150° C. by radiation heat transfer, and then maintaining the temperature for 12-72 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 1-10 rpm; the forward and reverse rotations in the same cycle last for 1-2 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 1-5 minutes; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 4-5 hours;

[0011] Step S4, centrifugally separating the precipitate, washing it, and then placing the precipitate in a vacuum drying oven at 100-110° C. for 2-5 hours;

[0012] Step S5: calcining the dried precipitate in a muffle furnace and obtaining a porous silicon-based molecular sieve after cooling.

[0013] Furthermore, the organic silicon source is one or more of methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate and n-butyl orthosilicate.

[0014] Furthermore, the template agent is one or more of urea, diethylamine, triethylamine, hexamethylenediamine, tetrapropylammonium hydroxide, hexamethylammonium bromide, hexamethylammonium chloride, hexamethylammonium hydroxide, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyldimethylamine oxide, tetradecyldimethylamine oxide, hexadecyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide and octadecyldihydroxyethylamine oxide.

[0015] Furthermore, the template agent is composed of tetrapropylammonium hydroxide and one of dodecyldimethylamine oxide, tetradecyldimethylamine oxide, hexadecyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide and octadecyldihydroxyethylamine oxide, and the mass ratio of the two is 10:0.5~1.3.

[0016] Furthermore, the high boiling point alcohol is one or more of ethylene glycol, glycerol, n-butanol and octanol.

[0017] Furthermore, in step S5, the precipitate is calcined in a muffle furnace at 500-600° C. for 5-12 hours.

[0018] Furthermore, in step S5, the temperature in the muffle furnace is first increased to 250-300°C at 10°C / min, and then increased to 500-600°C at 2°C / min.

[0019] Based on the same inventive concept, the present invention also provides a hydrothermal reactor for realizing the aforementioned method for preparing a porous silicon-based molecular sieve for CO2 capture, characterized in that it comprises:

[0020] The outer shell is cylindrical, and the top of the outer shell has a circular installation window; the inner side wall and the inner bottom wall of the outer shell are provided with electric heating elements; the top of the outer side wall of the outer shell is provided with a driven gear;

[0021] A cylindrical reactor body with an open top, the diameter of which is consistent with the diameter of the installation window; the lower portion of the reactor body extends through the installation window into the outer shell; the upper portion of the reactor body is located outside the outer shell, and a rack is provided on the outer wall thereof along the circumferential direction; the rack cooperates with the driven gear;

[0022] A sealing top cover, which is detachably mounted on the open top of the reactor body; the sealing top cover has a temperature detection installation port, a pressure detection installation port, and a safety valve; an electronic temperature sensor is installed in the temperature detection installation port; and an electronic pressure sensor is installed in the pressure detection installation port;

[0023] A motor, wherein the output end of the motor has a driving gear; the driving gear is meshed with the driven gear;

[0024] A controller is electrically connected to the electric heating element, the electronic temperature sensor, the electronic pressure sensor and the motor.

[0025] Furthermore, at least one group of annular straight cylindrical parts is provided on the inner bottom wall of the outer shell; each group of the annular straight cylindrical parts is composed of two annular straight cylindrical parts; the two annular straight cylindrical parts are arranged opposite to each other, and cooperate with the inner bottom wall of the outer shell to form an annular groove with a U-shaped cross-section, and the geometric center of the annular groove coincides with the axial center of the outer shell; at least one second support ball is rolled and laid in the annular groove; the second support ball is tangent to the groove side wall and the groove bottom wall of the annular groove at the same time, and the ball crown part of the first support ball protrudes out of the groove mouth of the annular groove.

[0026] And / or, at least three groups of L-shaped members are evenly arranged on the inner side wall of the outer shell in the circumferential direction; each group of L-shaped members is composed of two L-shaped members, which are arranged as a whole along the height direction of the outer shell and start from near the edge of the inner bottom wall of the outer shell; the two L-shaped members are arranged opposite to each other to form a structure with a "door"-shaped cross-section, and the notch formed by the two L-shaped members is toward the axial center of the outer shell; at least one first support ball is rolled and laid in an area surrounded by the two L-shaped members of the same group and the inner side wall of the outer shell; the first support ball is tangent to the side opposite to the L-shaped member and the inner side wall of the outer shell at the same time, and the crown of the first support ball protrudes out of the notch.

[0027] Furthermore, a plurality of first blades in a spiral ascending shape are evenly arranged on the inner side wall of the inner body of the reactor in a circumferential manner starting from the edge of the inner bottom wall;

[0028] And / or, a second blade is provided above the center of the inner bottom wall of the inner body of the reactor.

[0029] The beneficial effects of the present invention are:

[0030] 1. The preparation method of the porous silicon-based molecular sieve for CO2 capture in the present invention adopts a hydrothermal reactor without a mechanical stirring structure directly driven by a motor as the main synthesis structure, which can avoid the risk of gas leakage in traditional mechanical stirring and maintain the precise temperature and pressure in the hydrothermal reactor; at the same time, an appropriate amount of high-boiling-point alcohol is introduced into the preparation of the silicon-based molecular sieve to regulate the hydrolysis process of the organic silicon source, control the hydrothermal reaction rate, improve the uniformity and stability, regulate the pore characteristics of the precipitate and affect the particle size of the precipitate; finally, during the hydrothermal reaction process, the forward and reverse rotations are performed periodically, and the rotation speeds of each cycle are different, and the pause intervals are also different. The early stage of the hydrothermal reaction is a dynamic process with small and uniform grains, and the later stage is a static process with gradually increasing grain size, and finally a silicon-based molecular sieve with a high specific surface area and a large pore size is obtained, which has a good adsorption effect on carbon dioxide.

[0031] 2. The hydrothermal reactor of the present invention realizes the stable rotation of the reactor body by cooperating with the L-shaped component, the annular straight cylinder, the first supporting ball, the second supporting ball, the motor, the driving gear, the driven gear and the rack, which are arranged in the outer shell. Without the help of the traditional mechanical stirring structure directly driven by the motor, the risk of air leakage in the traditional mechanical stirring can be avoided, and the temperature and pressure in the hydrothermal reactor can be accurately maintained. At the same time, the mixture in the reactor body is periodically rotated forward and reversed according to the needs in the hydrothermal reaction process, and the rotation speed of each cycle is different, and the pause time is also different. The early stage of the hydrothermal reaction is a dynamic process, and the grains are small and uniform. The later stage is a static process, and the grains gradually increase. Finally, a silicon-based molecular sieve with a high specific surface area and a large pore size is obtained, which has a good adsorption effect on carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 It is a front view of the hydrothermal reactor in the embodiment.

[0034] Figure 2 Schematic diagram of the three-dimensional structure of the hydrothermal reactor in the embodiment.

[0035] Figure 3 Schematic diagram of the decomposition structure of the hydrothermal reactor in the embodiment

[0036] Figure 4 Schematic diagram of the three-dimensional structure of the outer shell in the embodiment.

[0037] Figure 5 for Figure 1 Cross-sectional view along the AA axis.

[0038] Figure 6 Schematic diagram of the three-dimensional structure of the reactor body.

[0039] The accompanying drawings are:

[0040] 100 - reactor body, 110 - discharge port, 120 - rack, 130 - first blade, 140 - second blade.

[0041] 200-sealed top cover, 210-temperature detection installation port, 220-pressure detection installation port, 230-safety valve.

[0042] 300 - outer shell, 310 - mounting window, 320 - L-shaped member, 321 - notch, 330 - annular straight cylinder, 340 - through hole, 350 - driven gear.

[0043] 400-First support ball.

[0044] 500-Second support ball. DETAILED DESCRIPTION

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing 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 should not be understood as limiting the present invention.

[0046] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0047] The embodiments of the invention are described in detail below with reference to the accompanying drawings. Example

[0048] A method for preparing a porous silicon-based molecular sieve for CO2 capture comprises the following steps:

[0049] Step S1, placing an organosilicon source, a template, water, and a high-boiling-point alcohol in a mass ratio of 1:0.1 to 0.5:20:0.15 into a closed hydrothermal reactor that is not provided with a mechanical stirring structure directly driven by a motor, gradually raising the temperature in the hydrothermal reactor to 40 to 50° C. by radiation heat transfer, and then keeping the temperature for 1 to 2 hours; while simultaneously maintaining the temperature during the heating and holding processes, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed during forward and reverse rotation is 100 to 150 rpm; the forward and reverse rotations in the same cycle last for 5 to 10 minutes respectively, and the pause interval between forward and reverse rotations in the same cycle is 0 to 5 seconds; the pause interval between reverse rotation in the previous cycle and forward rotation in the next cycle is 5 to 30 minutes;

[0050] Step S2: gradually raising the temperature in the hydrothermal reactor to 80-100° C. by radiation heat transfer, and then maintaining the temperature for 12-24 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 50-100 rpm; the forward and reverse rotations in the same cycle last for 3-5 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 30-60 seconds; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 1-2 hours;

[0051] Step S3, gradually raising the temperature in the hydrothermal reactor to 120-150° C. by radiation heat transfer, and then maintaining the temperature for 12-72 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 1-10 rpm; the forward and reverse rotations in the same cycle last for 1-2 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 1-5 minutes; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 4-5 hours;

[0052] Step S4, centrifugally separating the precipitate, washing it, and then placing the precipitate in a vacuum drying oven at 100-110° C. for 2-5 hours;

[0053] Step S5: calcining the dried precipitate in a muffle furnace and obtaining a porous silicon-based molecular sieve after cooling.

[0054] The organic silicon source is one or more of methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate and n-butyl orthosilicate.

[0055] The template agent is one or more of urea, diethylamine, triethylamine, hexyldiamine, tetrapropylammonium hydroxide, hexamethylammonium bromide, hexamethylammonium chloride, hexamethylammonium hydroxide, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyldimethylamine oxide, tetradecyldimethylamine oxide, cetyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide, and octadecyldihydroxyethylamine oxide. Preferably, the template agent is composed of tetrapropylammonium hydroxide and one of dodecyldimethylamine oxide, tetradecyldimethylamine oxide, cetyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide, and octadecyldihydroxyethylamine oxide, and the mass ratio of the two is 10:0.5-1.3.

[0056] The high boiling point alcohol is one or more of ethylene glycol, glycerol, n-butanol and octanol.

[0057] The precipitate is calcined in a muffle furnace at 500-600° C. for 5-12 hours. Preferably, the temperature in the muffle furnace is first increased to 250-300° C. at a rate of 10° C. / min, and then increased to 500-600° C. at a rate of 2° C. / min.

[0058] The preparation method of the porous silicon-based molecular sieve for CO2 capture in this embodiment adopts a hydrothermal reactor without a mechanical stirring structure directly driven by a motor as the main synthesis structure, which can avoid the risk of gas leakage in the traditional mechanical stirring and maintain the precise temperature and pressure in the hydrothermal reactor; at the same time, an appropriate amount of high-boiling-point alcohol is introduced in the preparation of the silicon-based molecular sieve to regulate the hydrolysis process of the organic silicon source, control the hydrothermal reaction rate, improve the uniformity and stability, regulate the pore characteristics of the precipitate and affect the particle size of the precipitate; finally, during the hydrothermal reaction process, the forward and reverse rotations are performed periodically, and the rotation speeds of each cycle are different, and the pause intervals are also different. The early stage of the hydrothermal reaction is a dynamic process with small and uniform grains, and the later stage is a static process with gradually increasing grain size, and finally a silicon-based molecular sieve with a high specific surface area and a large pore size is obtained, which has a good adsorption effect on carbon dioxide.

[0059] The following describes this with a more specific example.

[0060] The raw material compositions and test parameters of experiments 1# to 10# and control experiments 1# to 3# are shown in Table 1 below.

[0061] Table 1 Raw material composition and experimental parameters

[0062]

[0063] Table 1-1 Raw material composition and experimental parameters

[0064]

[0065] Table 1-2 Raw material composition and experimental parameters

[0066]

[0067] Table 1-3 Raw material composition and experimental parameters

[0068]

[0069] The test results of specific surface area, pore volume, average pore size and carbon dioxide adsorption capacity of the silicon-based molecular sieves prepared in Experiments 1# to 10# and Control Experiments 1# to 3# are shown in Table 2.

[0070] Among them, the carbon dioxide adsorption test method is:

[0071] Dry the silica molecular sieve at 110±5°C to constant weight and place in a desiccator for later use. Wipe the adsorption tube clean and weigh it as m1 (including the tube stopper, accurate to 0.1 mg). Load the prepared sample into the adsorption tube in two or three batches, with the silica molecular sieve layer height being 10±0.2 cm (height after tapping). After loading, coat the tube stopper with vaseline and tighten it. Weigh it together with the tube stopper and weigh it again as m2 (accurate to 0.1 mg). After weighing, insert the adsorption tube vertically into a constant temperature water bath (water bath temperature 25°C). Once everything is ready, purge the adsorption tube with high-purity helium, evacuate it, and then introduce carbon dioxide (calculated based on a molecular weight of 44). Evacuate to a vacuum of -0.09 MPa (gauge pressure). Then connect the carbon dioxide cylinder gas source and adjust the carbon dioxide flow rate to a stable level of 1670±70 mL / min. Then allow the carbon dioxide to pass through the sample for 1 hour. Remove the adsorption tube, wipe it clean, and weigh it as m3 (accurate to 1 mg). Then, introduce carbon dioxide into the adsorption tube and allow it to pass through the sample for 10 minutes. Repeat the above steps until the adsorption is saturated (the difference in mass between the two weighings is no more than 10 mg). Then, turn off the gas source and the test is complete.

[0072] The adsorption capacity of activated carbon for carbon dioxide:

[0073] Q=22.727(m3-m2) / (m2-m1)×100%

[0074] Where, m1-mass of adsorption tube, g;

[0075] m2-mass of carbon added to the adsorption tube before adsorption, g;

[0076] m3-mass of silicon-based molecular sieve and carbon dioxide added to the adsorption tube after adsorption, g;

[0077] Q-carbon dioxide adsorption amount (1atm, 25℃), mmol / g.

[0078] Table 2 Specific surface area and pore size

[0079]

[0080] From the data in Table 2, it can be seen that the introduction of high-boiling-point alcohol and the control of the stirring process in this embodiment will evenly affect the specific surface area, pore volume, average pore size and carbon dioxide adsorption capacity of the silicon-based molecular sieve.

[0081] Example 2

[0082] Figure 1 It is a front view of the hydrothermal reactor in the embodiment. Figure 2 Schematic diagram of the three-dimensional structure of the hydrothermal reactor in the embodiment. Figure 3 Schematic diagram of the decomposition structure of the hydrothermal reactor in the embodiment. Figures 1 to 3As shown in FIG, the hydrothermal reactor comprises a cylindrical reactor body 100 with an open top. A cylindrical discharge port 110 is located in the center of the outer bottom wall of the reactor body 100, and a discharge valve (not shown) is installed on the discharge port 110. A rack 120 is arranged along the circumference of the outer wall near the top of the reactor body 100. A sealing top cover 200 is connected to the open top of the reactor body 100 via a flange. The sealing top cover 200 has a temperature detection port 210, a pressure detection port 220, and a safety valve 230. An electronic temperature sensor (not shown) is installed in the temperature detection port 210, and an electronic pressure sensor (not shown) is installed in the pressure detection port 220. After adding the organosilicon source, template, water and high-boiling-point alcohol into the reactor body 100 in a mass ratio of 1:0.1 to 0.5:20:0.15, the sealing top cover 200 is installed, and then the hydrothermal crystallization process is completed in the closed structure formed by the reactor body 100 and the sealing top cover 200.

[0083] Figure 4 The hydrothermal reactor also includes a cylindrical outer shell 300, such as Figure 4 As shown in . The outer diameter of the outer shell 300 is larger than that of the reactor body 100, and a circular installation window 310 is provided on the top thereof. The diameter of the installation window 310 is consistent with the outer diameter of the reactor body 100. At least three groups of L-shaped members 320 are evenly arranged along the circumferential direction on the inner side wall of the outer shell 300, such as Figure 4 A total of five groups of L-shaped members 320 are shown; each group of L-shaped members 320 is composed of two L-shaped members 320, which are arranged along the height direction of the outer shell 300 and start from the edge of the inner bottom wall of the outer shell 300; the two L-shaped members 320 are arranged opposite each other to form a structure with a cross-section similar to a "door" shape, and the notch 321 formed by the two L-shaped members 320 is oriented towards the axial center of the outer shell 300; at least one group of annular straight cylindrical members 330 is provided on the inner bottom wall of the outer shell 300, such as Figure 4There is only one set of annular straight cylindrical members 330; each set of annular straight cylindrical members 330 is composed of two annular straight cylindrical members 330; the two annular straight cylindrical members 330 are arranged opposite each other and cooperate with the inner bottom wall of the outer shell 300 to form an annular groove with a U-shaped cross section, and the geometric center of the annular groove coincides with the axial center of the outer shell 300. If there are two or more sets of annular straight cylindrical members 330, they are arranged in a concentric circle. A through-hole 340 is provided at the center of the inner bottom wall of the outer shell 300. The diameter of the through-hole 340 matches the diameter of the discharge port 110. Electric heating elements (not shown) are evenly distributed on the inner sidewall and inner bottom wall of the outer shell 300. When in operation, the electric heating elements heat the mixture in the reactor body 100 through heat radiation. A driven gear 350 is provided at the top of the outer sidewall of the outer shell 300. The driven gear 350 meshes with the rack 120, thereby driving the forward and reverse rotation of the reactor body 100. At least one first support ball 400 is rolled and laid within the area surrounded by the L-shaped member 320 and the inner sidewall of the outer shell 300. The first support ball 400 is tangential to both the side opposite the L-shaped member 320 and the inner sidewall of the outer shell 300, and the crown of the first support ball 400 protrudes beyond the notch 321. At least one second support ball 500 is rolled and laid in an annular groove surrounded by two annular straight cylindrical members 330 of the same group and the inner bottom wall of the outer shell 300; the second support ball 500 is tangent to the opposite side of the annular straight cylindrical member 330 and the inner bottom wall of the outer shell 300, and the spherical crown part of the first support ball 400 protrudes out of the notch of the annular groove.

[0084] Figure 5 for Figure 1 The cross-sectional view along the AA direction. Figure 5 As shown in the figure, when the reactor body 100 is assembled with the outer shell 300, the lower portion of the reactor body 100 extends into the outer shell 300 through the installation window 310; the outer wall and bottom wall of the reactor body 100 roll in contact with the second support ball 500, and the discharge port 110 extends through the through hole 340 to the outside of the bottom wall of the outer shell 300; the lower portion of the outer wall of the reactor body 100 rolls in contact with the first support ball 400; the upper portion of the outer wall of the reactor body 100, where the rack 120 is located, is located outside the outer shell 300, and the rack 120 meshes with the driven gear 350. The hydrothermal reactor includes a controller and a motor (not shown). The motor has forward and reverse rotation functions and has a driving gear at its output end; the driving gear meshes with the driven gear 350, thereby driving the reactor body. The controller is electrically connected to the motor, electric heating element, electronic temperature sensor, and electronic pressure sensor.

[0085] Specifically, the specific control process implemented by the controller is:

[0086] Step S1, according to the mass ratio of 1:0.1 to 0.5:20:0.15, the organic silicon source, template, water and high boiling point alcohol are loaded into the reactor body 100, and then the sealing top cover 200 is installed. The electric heating element starts working, so that the temperature in the reactor body 100 gradually rises to 40-50°C, and then keeps warm for 1-2 hours; at the same time, during the heating and heat preservation process, the electric drive gear, the driven gear 350 and the rack 120 drive the reactor body 100 to rotate forward and reverse periodically, and the mixture in the reactor body 100 also rotates forward and reverse synchronously with the reactor body 100; the speed of the reactor body 100 during forward and reverse rotation is 100-150rpm; the reactor body 100 rotates forward and reverse in the same cycle The rotations last for 5 to 10 minutes respectively, and the pause interval between forward rotation and reverse rotation in the same cycle is 0 to 5 seconds; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle of the reactor body 100 is 5 to 30 minutes; in this stage, the forward and reverse rotation speeds of the reactor body 100 are high, and the pause intervals between forward rotation and reverse rotation in the same cycle and the previous and next cycles are short. The reactor body is in a fully dynamic state, which is conducive to enhancing the disorder of the mixture in the reactor body, improving the dispersion of the raw materials, and preventing rapid grain growth.

[0087] Step S2, the temperature in the hydrothermal reactor is gradually raised to 80-100°C by radiation heat transfer, and then kept warm for 12-24 hours; at the same time, during the heating and heat preservation process, the motor drives the reactor body 100 to rotate forward and reverse periodically through the driving gear, the driven gear 350 and the rack 120, and the mixture in the reactor body 100 also rotates forward and reverse synchronously with the reactor body 100; the speed of the reactor body 100 during forward and reverse rotation is 50-100 rpm; the reactor body The forward and reverse rotations of the reactor body 100 in the same cycle last for 3 to 5 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 30 to 60 seconds. The pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle of the reactor body 100 is 1 to 2 hours. Compared with the previous stage, the forward and reverse rotation speeds of the reactor body 100 in this stage are reduced, and the pause intervals between the forward and reverse rotations in the same cycle and the previous and next cycles are prolonged. This is a combination of dynamic and static conditions, forming grains of uniform size.

[0088] Step S3, the temperature in the hydrothermal reactor is gradually raised to 120-150°C by means of radiation heat transfer, and then kept warm for 12-72 hours; at the same time, during the heating and keeping warm process, the motor drives the reactor body 100 to rotate forward and reverse periodically through the driving gear, the driven gear 350 and the rack 120, and the mixture in the reactor body 100 also rotates forward and reverse synchronously with the reactor body 100; the speed of the reactor body 100 during forward and reverse rotation is 1-10 rpm; the reactor body 100 is the same The forward and reverse rotations within a cycle last for 1 to 2 minutes respectively, and the pause interval between forward and reverse rotations within the same cycle is 1 to 5 minutes; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle of the reactor body 100 is 4 to 5 hours; compared with the previous stage, the forward and reverse rotation speeds of the reactor body 100 in this stage are further reduced, and the pause intervals between forward and reverse rotations in the same cycle and the previous and next cycles are further extended, which belongs to a static situation. The grains gradually grow larger, forming precipitates of uniform size and precipitation.

[0089] In this embodiment, the stable rotation of the reactor body is achieved by cooperating with an L-shaped component, an annular straight cylinder, a first support ball, a second support ball, a motor, a driving gear, a driven gear and a rack, and is arranged in the outer shell. Without the help of a traditional mechanical stirring structure directly driven by a motor, the risk of air leakage in traditional mechanical stirring can be avoided, and the temperature and pressure in the hydrothermal reactor can be maintained accurately. At the same time, the mixture in the reactor body is periodically rotated forward and reversed according to the needs in the hydrothermal reaction process, and the rotation speed of each cycle is different, and the pause time is also different. The early stage of the hydrothermal reaction is a dynamic process, and the grains are small and uniform. The later stage is a static process, and the grains gradually increase, and finally a high specific surface area, large pore size silicon-based molecular sieve is obtained, which has a good adsorption effect on carbon dioxide.

[0090] Figure 6 It is a schematic diagram of the three-dimensional structure of the reactor body. Figure 6 As shown in FIG, a plurality of first blades 130 are arranged in a spiral pattern on the inner sidewall of the reactor body 100, extending from the bottom edge thereof. A second blade 140 is positioned above the center of the inner bottom wall of the reactor body 100. The second blade 140 comprises a triangular-shaped thin plate or a plurality of intersecting triangular thin plates. In this embodiment, the first and second blades provide different levels of disturbance to the mixture in the reactor body during synchronous and simultaneous forward and reverse rotation of the reactor body, altering the flow of the mixture near the inner sidewall and in the center of the reactor body, promoting dispersion, and regulating the size of the precipitate.

Claims

1. A method for preparing a porous silicon-based molecular sieve for CO2 capture, characterized in that: The following steps are involved: Step S1, placing an organosilicon source, a template, water, and a high-boiling-point alcohol in a mass ratio of 1:0.1 to 0.5:20:0.15 into a closed hydrothermal reactor that is not provided with a mechanical stirring structure directly driven by a motor, gradually raising the temperature in the hydrothermal reactor to 40 to 50° C. by radiation heat transfer, and then keeping the temperature for 1 to 2 hours; while maintaining the temperature during the heating and holding process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 100 to 150 rpm; The forward rotation and reverse rotation in one cycle last for 5 to 10 minutes respectively, and the pause interval between the forward rotation and reverse rotation in the same cycle is 0 to 5 seconds; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 5 to 30 minutes; wherein the template agent is composed of tetrapropylammonium hydroxide and one of dodecyldimethylamine oxide, tetradecyldimethylamine oxide, hexadecyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide and octadecyldihydroxyethylamine oxide; Step S2: gradually raising the temperature in the hydrothermal reactor to 80-100° C. by radiation heat transfer, and then maintaining the temperature for 12-24 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 50-100 rpm; the forward and reverse rotations in the same cycle last for 3-5 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 30-60 seconds; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 1-2 hours; Step S3, gradually raising the temperature in the hydrothermal reactor to 120-150° C. by radiation heat transfer, and then maintaining the temperature for 12-72 hours; during the heating and maintaining process, maintaining the mixture in the hydrothermal reactor in periodic forward and reverse rotation; the speed of the forward and reverse rotation is 1-10 rpm; the forward and reverse rotations in the same cycle last for 1-2 minutes respectively, and the pause interval between the forward and reverse rotations in the same cycle is 1-5 minutes; the pause interval between the reverse rotation in the previous cycle and the forward rotation in the next cycle is 4-5 hours; Step S4, centrifugally separating the precipitate, washing it, and then placing the precipitate in a vacuum drying oven at 100-110° C. for 2-5 hours; Step S5: calcining the dried precipitate in a muffle furnace and obtaining a porous silicon-based molecular sieve after cooling.

2. The method for preparing a porous silicon-based molecular sieve for CO2 capture according to claim 1, characterized in that: The organic silicon source is one or more of methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate and n-butyl orthosilicate.

3. The method for preparing a porous silicon-based molecular sieve for CO2 capture according to claim 1, characterized in that: The mass ratio of the tetrapropylammonium hydroxide to one of dodecyldimethylamine oxide, tetradecyldimethylamine oxide, hexadecyldimethylamine oxide, dodecyldihydroxyethylamine oxide, tetradecyldihydroxyethylamine oxide and octadecyldihydroxyethylamine oxide is 10:0.5-1.

3.

4. The method for preparing a porous silicon-based molecular sieve for CO2 capture according to claim 1, characterized in that: The high boiling point alcohol is one or more of ethylene glycol, glycerol, n-butanol and octanol.

5. The method for preparing a porous silicon-based molecular sieve for CO2 capture according to claim 1, characterized in that: In step S5, the precipitate is calcined in a muffle furnace at 500-600° C. for 5-12 hours.

6. The method for preparing a porous silicon-based molecular sieve for CO2 capture according to claim 5, characterized in that: In step S5, the temperature in the muffle furnace is first increased to 250-300° C. at a rate of 10° C. / min, and then increased to 500-600° C. at a rate of 2° C. / min.

Images