System and process for preparing methanol by combining green hydrogen and carbon dioxide

Abstract

The invention provides a system and a process for preparing methanol by combining green hydrogen and carbon dioxide, the system comprises an absorption tower, a desorption tower, an electrolytic bath, a washer, a reactor and a rectifying tower, the absorption tower captures and dissolves carbon dioxide in flue gas and air into an absorbent to form rich liquor rich in carbon dioxide; the desorption tower is used for heating, gasifying and releasing carbon dioxide rich liquor in the absorption tower, the electrolytic bath is used for preparing hydrogen through purified water, and the washer is used for removing impurities and purifying the hydrogen prepared by the electrolytic bath; according to the invention, the arranged cleaning structure is driven by the motor to work in the preparation process of methanol, and the structures on the outer walls of the two ends of the baffle plate are cleaned and scraped, so that the heat transfer effect of the baffle plate is prevented from being influenced by scaling generated by long-time storage of a heating medium in the reactor and on the outer side of the tube nest; and scales can be cleaned in real time during working, so that the time for dismounting and cleaning the whole deflection baffle plate subsequently is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of methanol preparation, and in particular to a system and process for preparing methanol by combining green hydrogen and carbon dioxide. Background Art

[0002] With the increase of industrialization and energy consumption, global carbon dioxide emissions continue to rise, leading to global warming and environmental degradation. In response to climate change, countries around the world have proposed emission reduction targets. This requires effective measures to reduce greenhouse gas emissions in the field of energy production and consumption. At the same time, the rapid development of renewable energy such as solar energy and wind energy has provided a rich source of electricity for hydrogen production by electrolysis of water. No carbon emissions are generated during the process of hydrogen production by electrolysis of water, so it is called "green hydrogen". Green hydrogen, as the cleanest ultimate energy, has the advantages of zero carbon emissions, storability, and transportability. It is an important direction for energy transformation. Hydrogen production by electrolysis of water using renewable energy can achieve time and space translation of energy and improve the flexibility of the power system.

[0003] In the prior art, the preparation of methanol by combining green hydrogen and carbon dioxide is an innovative technology that has emerged in recent years. This technology reacts the captured carbon dioxide with green hydrogen under the action of a catalyst to generate methanol, realizing the resource utilization of carbon dioxide and the efficient consumption of green hydrogen. Compared with the traditional coal-to-methanol, the process of preparing methanol by combining green hydrogen and carbon dioxide has the advantages of environmental friendliness, resource recycling, and high economic benefits. This process not only reduces carbon dioxide emissions, but also improves energy utilization efficiency, which helps to alleviate the shortage of fossil fuels and environmental pollution. In the preparation process of methanol, it is necessary to react carbon dioxide and green hydrogen through a reactor to prepare methanol. In order to improve the heat exchange effect of the internal tubes, the reactor will use a baffle to force the fluid to be baffled multiple times according to the prescribed distance, increase the turbulence of the fluid, and make the reaction more sufficient and efficient. However, the common baffle does not have a self-cleaning mechanism. After long-term use, the baffle inside the reactor needs to be disassembled, cleaned, and reassembled, which is time-consuming and labor-intensive in the process, affecting the preparation efficiency of methanol. How to invent a system and process for preparing methanol by combining green hydrogen and carbon dioxide to solve these problems has become a problem that needs to be solved by technicians in this field. Summary of the invention

[0004] In order to make up for the above deficiencies, the present invention provides a system and process for preparing methanol by combining green hydrogen and carbon dioxide, aiming to solve the problem that common baffles have no self-cleaning mechanism.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a system for preparing methanol by combining green hydrogen and carbon dioxide, the system comprising an absorption tower, a desorption tower, an electrolyzer, a scrubber, a reactor, and a distillation tower. The absorption tower captures carbon dioxide in flue gas and air and dissolves it into an absorbent to form a rich liquid rich in carbon dioxide. The desorption tower heats and gasifies the carbon dioxide rich liquid in the absorption tower and releases it. The electrolyzer prepares hydrogen through pure water. The scrubber removes impurities and purifies the hydrogen prepared by the electrolyzer. A cleaning mechanism is installed in the reactor.

[0006] Preferably, a feed port is provided at the upper end of the reactor, a medium inlet and a medium outlet are respectively provided on the side walls of the reactor, a discharge port is provided at the bottom end of the reactor, mounting plates are installed on the side walls at both ends of the reactor, a plurality of deflector baffles are installed between the two mounting plates, one side end of the deflector baffle has an opening, the opening directions between adjacent deflector baffles are opposite, and a plurality of array tubes are installed between the two mounting plates.

[0007] Preferably, the cleaning mechanism includes a motor, a main shaft, a mounting block, a cleaning block and a fixed shaft, the motor is installed at the upper end of the reactor, the output end of the motor is fixedly connected to one end of the main shaft, and the outer wall of the main shaft is rotatably connected to the inner wall of the reactor, the mounting plate and the deflector baffle respectively.

[0008] Preferably, one end of the plurality of mounting blocks is fixedly connected to the side wall of the main shaft, and two mounting blocks are located as a group and are respectively mounted on both sides of the deflector baffle.

[0009] Preferably, a receiving groove is provided on one side of the cleaning block, fixed shafts are installed on the inner walls at both ends of the receiving groove, and positioning mechanisms are respectively provided on the side of the mounting block and the cleaning block away from the receiving groove.

[0010] Preferably, the positioning mechanism includes a first limit groove and a second limit groove opened on the outer wall of one side of the mounting block and the cleaning block, the inner walls of the first limit groove and the second limit groove are installed with magnets, the outer walls of the two fixed shafts are rotatably connected to two symmetrical adjusting rods, the adjusting rods are installed with torsion springs near the inner walls of the fixed shafts, the two ends of the torsion springs are respectively fixedly connected to the inner walls of the fixed shaft and the adjusting rod, and a scraper rod is installed on one side of the adjusting rod.

[0011] Preferably, a buffer groove is provided inside the adjusting rod, a sliding groove is provided at one end of the buffer groove, a spring is installed at one end of the buffer groove, a side wall of one end of the spring is fixedly connected to a limiting ring slidably connected to the outer wall of the buffer groove, the inner wall of the limiting ring is installed with a sliding rod slidably connected to the inner wall of the sliding groove, a positioning block slidably connected to the inner wall of the first limiting groove is installed at one end of the sliding rod, and another positioning block at one end of the sliding rod is slidably connected to the inner wall of the second limiting groove, the positioning block is adsorbed by a magnet and the limiting groove, and the multiple cleaning blocks are fixed to each other by a positioning mechanism in cooperation with the adjusting rod, and a scraping groove is provided at the bottom end of the mounting block and the cleaning block.

[0012] Preferably, a stirring mechanism is installed between the two deflection baffles, and the stirring mechanism includes an inner ring frame, an outer ring frame, a connecting rod, a rotating shaft, gears and blades. The inner ring frame and the outer ring frame are fixed by a connecting rod, and one end of the connecting rod is fixedly connected to the inner wall of the reactor.

[0013] Preferably, the outer walls of the multiple rotating shafts are rotatably connected to the inner walls of the inner ring frame and the outer ring frame respectively, one end of the blade is fixedly connected to the side wall of the rotating shaft, one end of the rotating shaft is fixedly connected to the gear, and the outer walls on both sides of the mounting block and the cleaning block are equipped with racks meshing with the gears, and the racks are arc-shaped teeth.

[0014] A process for preparing methanol by combining green hydrogen and carbon dioxide comprises the following steps: S1: Hydrogen production by water electrolysis Using electricity generated from renewable energy, water is split into hydrogen and oxygen using an electrolyser; S2: Hydrogen purification The hydrogen obtained in S1 is input into the scrubber, and the moisture and oxygen are removed respectively by dry adsorbent and membrane separation technology. The separated hydrogen enters the scrubber through the upper pipeline, and the hydrogen is cooled, washed and dripped by the dripping net to obtain pure hydrogen; S3: Carbon dioxide capture The absorption tower is used to capture and collect carbon dioxide from industrial emissions and the atmosphere. After the flue gas enters the absorption tower, it contacts the absorbent sprayed from the top of the tower in countercurrent, reacts chemically with the acidic carbon dioxide, and absorbs it. After absorption, the absorbent becomes a rich liquid rich in carbon dioxide and is discharged from the absorption tower; S4: Carbon dioxide release The rich liquid obtained by S3 is sent to the desorption tower through the pump body. The rich liquid in the desorption tower and the air sucked in by the exhaust fan of the desorption tower are in reverse contact in the tower. The carbon dioxide in the solution is gradually desorbed and discharged. The solution after desorption becomes a lean liquid, which flows out from the lower part of the desorption tower and enters the lean liquid tank. The lean liquid is pumped into the absorption tower through the lean liquid pump and recycled to continue the carbon dioxide absorption process. S5: Methanol Preparation The green hydrogen obtained in step S2 and the carbon dioxide obtained in step S4 are introduced into the reactor at a molar ratio, and a heating medium is introduced into the outer side of the tubes in the reactor to heat the tubes. The raw gas introduced into the tubes contacts with the catalyst to promote the mixing reaction of methanol. Under the action of the catalyst, the hydrogen and carbon dioxide react chemically in the reactor, and the generated methanol is discharged to the outside. S6: Methanol Purification The methanol obtained in step S5 is purified, and after the crude methanol enters the distillation tower 10, it is heated for evaporation and condensed for reflux to achieve separation of methanol from other components, thereby obtaining a high-purity methanol product.

[0015] The beneficial effects of the present invention are: The cleaning structure is driven by a motor to work during the preparation of methanol, and the structures of the outer walls at both ends of the baffle are cleaned and scraped to avoid the scaling caused by the long-term storage of the heating medium inside the reactor and outside the tubes, which affects the heat transfer effect of the baffle. The scaling can be cleaned in real time while working, saving the time required for subsequent disassembly and cleaning of the entire baffle, and improving the cleaning efficiency. The positioning mechanism provided between the installation block and the cleaning block and the cleaning block cooperates with the adjusting rod to ensure that the cleaning mechanism can pass through the tubes while working, and the scraper rod below the tubes scrapes and cleans the scale near the area around the tubes on the baffle plate, thereby avoiding the path of the cleaning mechanism being blocked by the tubes and affecting the cleaning range, so that the outer surface of the baffle plate can be completely cleaned, improving the effect of scale cleaning, ensuring the heat transfer effect of the baffle plate, and improving the rate of preparing methanol; The stirring mechanism is set up to make multiple blades rotate in sequence as the cleaning mechanism works. The surrounding medium is stirred during the rotation process, which can change the flow state of the shell-side fluid and form a more complex flow path, thereby increasing the degree of turbulence. The increase in the degree of turbulence helps to break the fluid boundary layer, improve the heat transfer coefficient, and thus improve the heat transfer efficiency of the entire reactor. At the same time, the rotating blades can also help to distribute the shell-side fluid more evenly, avoid short circuits or dead zones in the fluid in the reactor, and ensure that the fluid can fully contact the tubes, thereby improving the heat transfer effect. In some cases, solid particles or sediments in the fluid are prone to form scaling on the inner wall of the reactor or the surface of the tubes, affecting the heat transfer efficiency and the normal operation of the reactor. The rotating blades can reduce the occurrence of scaling by continuously changing the flow state of the fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a process flow chart of preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Figure 2 This is a flow chart of a process equipment for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a reactor in a system for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Figure 4 This is a half-section diagram of the reactor structure of a system for preparing methanol by combining green hydrogen and carbon dioxide, provided in an embodiment of the present invention; Figure 5 This is an exploded view of the partial structure of a system reactor for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Figure 6 It is a schematic diagram of a partial structure of a system reactor for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Figure 7 The present invention provides a method for preparing methanol by combining green hydrogen and carbon dioxide. Figure 6 A magnified view of the structure of the middle A area; Figure 8 It is a schematic diagram of a cleaning mechanism in a system reactor for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention; Fig. 9 It is a side view of a cleaning mechanism in a reactor of a system for preparing methanol by combining green hydrogen and carbon dioxide provided by an embodiment of the present invention; Fig.10 It is a half-section diagram of a cleaning mechanism in a reactor of a system for preparing methanol by combining green hydrogen and carbon dioxide provided by an embodiment of the present invention; Fig.11 A system for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention Fig.10 A magnified view of the structure of the middle B area; Fig.12 A system for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention Fig.10 A magnified view of the structure of the middle C region; Fig.13A system for preparing methanol by combining green hydrogen and carbon dioxide provided in an embodiment of the present invention Fig.10 Enlarged view of the structure of the middle C region.

[0018] In the figure: 1. Absorption tower; 2. Desorption tower; 3. Electrolyzer; 4. Scrubber; 5. Reactor; 51. Feeding port; 52. Medium inlet; 53. Medium outlet; 54. Discharging port; 55. Mounting plate; 56. Baffle plate; 57. Tube array; 6. Cleaning mechanism; 61. Motor; 62. Main shaft; 63. Mounting block; 64. Cleaning block; 641. Storage tank; 65. Fixed shaft; 66. Rack; 7. Positioning mechanism ; 71. first limiting groove; 72. second limiting groove; 73. magnet; 74. adjusting rod; 741. buffer groove; 742. slide groove; 743. scraper rod; 75. torsion spring; 76. spring; 77. limiting ring; 78. slide rod; 79. positioning block; 8. scraper groove; 9. stirring mechanism; 91. inner ring frame; 92. outer ring frame; 93. connecting rod; 94. rotating shaft; 95. gear; 96. blade; 10. distillation tower. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1, reference Figure 3-Figure 5 , Figure 8-Figure 9 A system for preparing methanol by combining green hydrogen and carbon dioxide, the system includes an absorption tower 1, a desorption tower 2, an electrolyzer 3, a scrubber 4, a reactor 5, and a distillation tower 10. The absorption tower 1 captures carbon dioxide in flue gas and air and dissolves it into an absorbent to form a rich liquid rich in carbon dioxide. The desorption tower 2 heats and gasifies the carbon dioxide rich liquid in the absorption tower 1 and releases it. The electrolyzer 3 prepares hydrogen through pure water. The scrubber 4 removes impurities and purifies the hydrogen prepared by the electrolyzer 3. A cleaning mechanism 6 is installed in the reactor 5.

[0021] Further, a loading port 51 is provided at the upper end of the reactor 5, a medium inlet 52 and a medium outlet 53 are respectively provided on the side walls of the reactor 5, a discharge port 54 is provided at the bottom end of the reactor 5, mounting plates 55 are installed on the side walls at both ends of the reactor 5, a plurality of baffle plates 56 are installed between the two mounting plates 55, one side end of the baffle plate 56 has an opening, and the opening directions between adjacent baffle plates 56 are opposite, a plurality of array tubes 57 are installed between the two mounting plates 55, and a cleaning mechanism 6 includes a motor 61, a main shaft 62, a mounting block 63, a cleaning block 64 and a fixed shaft 65, the motor 61 is installed at the upper end of the reactor 5, the output end of the motor 61 is fixedly connected to one end of the main shaft 62, the outer wall of the main shaft 62 is rotatably connected to the inner wall of the reactor 5, the mounting plate 55 and the baffle plate 56, one end of the plurality of mounting blocks 63 is fixedly connected to the side wall of the main shaft 62, and two mounting blocks 63 are located in a group and are respectively installed on both sides of the baffle plate 56; It should be noted that: in the process of preparing methanol through the reactor 5, the main shaft 62 in the cleaning mechanism 6 drives multiple mounting blocks 63 and cleaning blocks 64 near the outer walls at both ends of the baffle plate 56 to rotate. During the rotation process, the mounting blocks 63 and the cleaning blocks 64 clean and scrape the structures of the outer walls at both ends of the baffle plate 56 through the scraping grooves 8 opened at the bottom, so as to avoid scaling caused by long-term storage of the heating medium inside the reactor 5 and outside the tube array 57, which affects the heat transfer effect of the baffle plate 56. The scaling can be cleaned in real time during operation, which saves the time required for subsequent disassembly and cleaning of the entire baffle plate 56, thereby improving the cleaning efficiency.

[0022] Example 2, see Figure 10-13 , based on the first embodiment, in order to avoid the existence of the tube array 57 causing the cleaning mechanism 6 to be unable to clean the local area during the rotation process; Furthermore, a receiving groove 641 is provided on one side of the cleaning block 64, and a fixed shaft 65 is installed on the inner wall at both ends of the receiving groove 641. A positioning mechanism 7 is respectively provided on the side of the mounting block 63 and the cleaning block 64 away from the receiving groove 641. The positioning mechanism 7 includes a first limiting groove 71 and a second limiting groove 72 provided on the outer wall of one side of the mounting block 63 and the cleaning block 64. A magnet 73 is installed on the inner wall of the first limiting groove 71 and the second limiting groove 72. Two symmetrical adjusting rods 74 are rotatably connected to the outer walls of the two fixed shafts 65. A torsion spring 75 is installed on the inner wall of the adjusting rod 74 close to the fixed shaft 65. The two ends of the torsion spring 75 are respectively fixedly connected to the inner wall of the fixed shaft 65 and the adjusting rod 74. A scraper rod 743 is installed on one side of the adjusting rod 74. 4 is provided with a buffer groove 741, one end of the buffer groove 741 is provided with a slide groove 742, one end of the buffer groove 741 is installed with a spring 76, one end of the side wall of the spring 76 is fixedly connected with a limiting ring 77 that is slidably connected to the outer wall of the buffer groove 741, the inner wall of the limiting ring 77 is provided with a slide rod 78 that is slidably connected to the inner wall of the slide groove 742, one end of the slide rod 78 is provided with a positioning block 79 that is slidably connected to the inner wall of the first limiting groove 71, the positioning block 79 at one end of the other slide rod 78 is slidably connected to the inner wall of the second limiting groove 72, the positioning block 79 is adsorbed by the magnet 73 and the limiting groove, the plurality of cleaning blocks 64 are fixed by the positioning mechanism 7 in cooperation with the adjusting rod 74, and the bottom ends of the mounting block 63 and the cleaning block 64 are provided with a scraping groove 8.

[0023] The cam 74 is pressed against the locking cam 76 to release the locking cam 76, which is then retracted to lock the locking cam 76. The cam 74 is pressed against the locking cam 76 and the locking cam 76 is released. The side adjustment rod 74 is fixed in another adjustment groove to ensure the fixation between the mounting block 63 and the cleaning block 64, and is subsequently supported by the array tube 57 for rotation. While ensuring the operation of the cleaning mechanism 6, the array tube 57 can be passed through the array tube 57, and the adjustment rod 74 is restored after passing through the array tube 57, so that the scraper rod 743 below can scrape and clean the scale of the baffle plate 56 near the array tube 57 surrounding area, thereby avoiding the path of the cleaning mechanism 6 being blocked by the array tube 57 and affecting the cleaning range, so that the outer surface of the baffle plate 56 can be completely cleaned, thereby improving the effect of scale cleaning, ensuring the heat transfer effect of the baffle plate 56, and improving the rate of preparing methanol.

[0024] Example 3, reference Figure 6-Figure 7, based on Example 1, in order to improve the heat transfer effect of the heating medium inside the entire reactor 5 to the tube array 57; Furthermore, a stirring mechanism 9 is installed between the two deflector baffles 56, and the stirring mechanism 9 includes an inner ring frame 91, an outer ring frame 92, a connecting rod 93, a rotating shaft 94, a gear 95 and a blade 96. The inner ring frame 91 and the outer ring frame 92 are fixed by the connecting rod 93, one end of the connecting rod 93 is fixedly connected to the inner wall of the reactor 5, the outer walls of the multiple rotating shafts 94 are rotatably connected to the inner walls of the inner ring frame 91 and the outer ring frame 92 respectively, one end of the blade 96 is fixedly connected to the side wall of the rotating shaft 94, one end of the rotating shaft 94 is fixedly connected to the gear 95, and the outer walls of both sides of the mounting block 63 and the cleaning block 64 are installed with racks 66 meshing with the gear 95, and the rack 66 is an arc-shaped tooth.

[0025] It should be noted that: when the cleaning mechanism 6 cleans the baffle 56, the rotating mounting block 63 and the rack 66 above the cleaning block 64 rotate, and in the process of rotation, the gear 95 on the stirring mechanism 9 is meshed in turn to make it rotate, thereby driving the blades 96 on the outside of the rotating shaft 94 to rotate, and the surrounding medium is stirred during the rotation process, which can change the flow state of the shell-side fluid, so that it forms a more complex flow path, thereby increasing the degree of turbulence. The increase in the degree of turbulence helps to break the fluid boundary layer, improve the heat transfer coefficient, and thus improve the heat transfer efficiency of the entire reactor 5. At the same time, the rotating blades 96 can also help to distribute the shell-side fluid more evenly, avoid short circuits or dead zones in the fluid in the reactor 5, and ensure that the fluid can fully contact the tube array 57, thereby improving the heat transfer effect. In some cases, solid particles or sediments in the fluid are prone to form scaling on the inner wall of the reactor 5 or the surface of the tube array 57, affecting the heat transfer efficiency and the normal operation of the reactor 5, and the rotating blades 96 can reduce the occurrence of scaling by continuously changing the flow state of the fluid.

[0026] Example 1, with reference to Figure 1-Figure 2 , a process for preparing methanol by combining green hydrogen and carbon dioxide, comprising the following steps: S1: Hydrogen production by water electrolysis Using electricity generated from renewable energy, water is split into hydrogen and oxygen through an electrolyzer 3; S2: Hydrogen purification The hydrogen obtained in S1 is input into the scrubber 4, and the moisture and oxygen are removed respectively by the dry adsorbent and membrane separation technology. The separated hydrogen enters the scrubber 4 through the upper pipeline, and the hydrogen is cooled, washed and dripped by the dripping net to obtain pure hydrogen; S3: Carbon dioxide capture The absorption tower 1 is used to capture and collect carbon dioxide from industrial emissions and the atmosphere. After the flue gas enters the absorption tower 1, it countercurrently contacts with the absorbent sprayed from the top of the tower, reacts chemically with the acidic carbon dioxide, and absorbs it. After absorption, the absorbent becomes a rich liquid rich in carbon dioxide and is discharged from the absorption tower 1; S4: Carbon dioxide release The rich liquid obtained by S3 is sent to the desorption tower 2 through the pump body. The rich liquid in the desorption tower 2 and the air sucked in by the exhaust fan of the desorption tower 2 are in reverse contact in the tower. The carbon dioxide in the solution is gradually desorbed and discharged. The solution after desorption becomes a lean liquid, which flows out from the lower part of the desorption tower 2 and enters the lean liquid tank. The lean liquid is pumped into the absorption tower 1 through the lean liquid pump, and is recycled to continue the carbon dioxide absorption process. S5: Methanol Preparation The green hydrogen obtained in step S2 and the carbon dioxide obtained in step S4 are introduced into the reactor 5 at a molar ratio of 3:1, and a heating medium is introduced into the outer side of the tube array 57 inside the reactor 5 to heat the tube array 57. The raw gas introduced into the tube array 57 contacts with the catalyst to promote the mixing reaction of methanol. Under the action of the catalyst, the hydrogen and the carbon dioxide react chemically in the reactor 5, and the generated methanol is discharged to the outside. S6: Methanol Purification The methanol obtained in step S5 is purified, and after the crude methanol enters the distillation tower 10, it is heated for evaporation and condensed for reflux to achieve separation of methanol from other components, thereby obtaining a high-purity methanol product.

[0027] It should be noted that the specific model and specifications of the motor need to be selected and determined based on the actual specifications of the device, and the specific selection calculation method adopts the existing technology in this field, so it will not be described in detail.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for producing methanol by combining green hydrogen and carbon dioxide, characterized in that: The system comprises an absorption tower (1), a desorption tower (2), an electrolyzer (3), a scrubber (4), a reactor (5), and a distillation tower (10). The absorption tower (1) captures carbon dioxide in flue gas and air and dissolves the carbon dioxide in an absorbent to form a rich liquid rich in carbon dioxide. The desorption tower (2) heats and gasifies the carbon dioxide rich liquid in the absorption tower (1) for release. The electrolyzer (3) prepares hydrogen using pure water. The scrubber (4) removes impurities and purifies the hydrogen prepared by the electrolyzer (3). A cleaning mechanism (6) is installed in the reactor (5).

2. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 1, characterized in that: The reactor (5) is provided with a feed port (51) at the upper end, a medium inlet (52) and a medium outlet (53) are respectively provided on the side walls of the reactor (5), and a discharge port (54) is provided at the bottom end of the reactor (5). Mounting plates (55) are installed on the side walls at both ends of the reactor (5), and a plurality of baffle plates (56) are installed between two of the mounting plates (55). One side end of the baffle plate (56) has an opening, and the opening directions between adjacent baffle plates (56) are opposite. A plurality of tube arrays (57) are installed between the two mounting plates (55).

3. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 2, characterized in that: The cleaning mechanism (6) comprises a motor (61), a main shaft (62), a mounting block (63), a cleaning block (64) and a fixed shaft (65); the motor (61) is mounted on the upper end of the reactor (5); the output end of the motor (61) is fixedly connected to one end of the main shaft (62); and the outer wall of the main shaft (62) is rotatably connected to the inner wall of the reactor (5), the mounting plate (55) and the baffle plate (56).

4. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 3, characterized in that: One end of the plurality of mounting blocks (63) is fixedly connected to the side wall of the main shaft (62), and two mounting blocks (63) form a group and are respectively mounted on both sides of the deflector baffle (56).

5. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 4, characterized in that: A receiving groove (641) is provided on one side of the cleaning block (64), fixed shafts (65) are installed on the inner walls at both ends of the receiving groove (641), and positioning mechanisms (7) are respectively provided on the sides of the mounting block (63) and the cleaning block (64) away from the receiving groove (641).

6. A system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 5, characterized in that: The positioning mechanism (7) comprises a first limiting groove (71) and a second limiting groove (72) formed on the outer wall of one side of the mounting block (63) and the cleaning block (64); the inner walls of the first limiting groove (71) and the second limiting groove (72) are provided with magnets (73); the outer walls of the two fixed shafts (65) are rotatably connected to two symmetrical adjustment rods (74); the adjustment rods (74) are provided with torsion springs (75) near the inner walls of the fixed shafts (65); the two ends of the torsion springs (75) are respectively fixedly connected to the inner walls of the fixed shafts (65) and the adjustment rods (74); and a scraper rod (743) is provided on one side of the adjustment rods (74).

7. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 6, characterized in that: A buffer groove (741) is provided inside the adjusting rod (74), a slide groove (742) is provided at one end of the buffer groove (741), a spring (76) is installed at one end of the buffer groove (741), a side wall at one end of the spring (76) is fixedly connected to a limiting ring (77) slidably connected to the outer wall of the buffer groove (741), an inner wall of the limiting ring (77) is installed with a sliding rod (78) slidably connected to the inner wall of the slide groove (742), one end of the sliding rod (78) is installed with a positioning block (79) slidably connected to the inner wall of the first limiting groove (71), a positioning block (79) at one end of another sliding rod (78) is slidably connected to the inner wall of the second limiting groove (72), the positioning block (79) is adsorbed by the magnet (73) and the limiting groove, the plurality of cleaning blocks (64) are fixed by a positioning mechanism (7) in cooperation with the adjusting rod (74), and a scraping groove (8) is provided at the bottom of the mounting block (63) and the cleaning block (64).

8. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 7, characterized in that: A stirring mechanism (9) is installed between the two baffle plates (56), the stirring mechanism (9) comprising an inner ring frame (91), an outer ring frame (92), a connecting rod (93), a rotating shaft (94), a gear (95) and blades (96), the inner ring frame (91) and the outer ring frame (92) are fixed by a connecting rod (93), and one end of the connecting rod (93) is fixedly connected to the inner wall of the reactor (5).

9. The system for preparing methanol by combining green hydrogen and carbon dioxide according to claim 8, characterized in that: The outer walls of the plurality of rotating shafts (94) are rotatably connected to the inner walls of the inner ring frame (91) and the outer ring frame (92), respectively; one end of the blade (96) is fixedly connected to the side wall of the rotating shaft (94); one end of the rotating shaft (94) is fixedly connected to the gear (95); and racks (66) meshingly connected to the gear (95) are mounted on the outer walls of both sides of the mounting block (63) and the cleaning block (64); the racks (66) are arc-shaped teeth.

10. A process for preparing methanol by combining green hydrogen and carbon dioxide according to claims 1-9, characterized in that: The following steps are involved: S1: Hydrogen production by water electrolysis Using electricity generated from renewable energy, water is split into hydrogen and oxygen using an electrolyzer (3); S2: Hydrogen purification The hydrogen obtained in S1 is input into the scrubber (4), and water and oxygen are removed respectively by using a dry adsorbent and a membrane separation technology. The separated hydrogen enters the scrubber (4) through an upper pipeline, and the hydrogen undergoes cooling, washing, and dripping with a dripping net to obtain pure hydrogen; S3: Carbon dioxide capture An absorption tower (1) is used to capture and collect carbon dioxide from industrial emissions and the atmosphere. After the flue gas enters the absorption tower (1), it is countercurrently contacted with an absorbent sprayed from the top of the tower, chemically reacts with the acidic carbon dioxide, and absorbs it. After the absorption, the absorbent becomes a rich liquid rich in carbon dioxide, which is discharged from the absorption tower (1); S4: Carbon dioxide release The rich liquid obtained by S3 is sent to the desorption tower (2) through the pump body. The rich liquid in the desorption tower (2) and the air sucked into the desorption tower (2) by the exhaust fan are in reverse contact in the tower. The carbon dioxide in the solution is gradually desorbed and discharged. The solution after desorption becomes a lean liquid, which flows out from the lower part of the desorption tower (2) and enters the lean liquid tank. The lean liquid is pumped into the absorption tower (1) through the lean liquid pump, and is recycled to continue the carbon dioxide absorption process. S5: Methanol Preparation The green hydrogen obtained in step S2 and the carbon dioxide obtained in step S4 are introduced into the reactor (5) at a molar ratio of 3:1, a heating medium is introduced into the outer side of the tube array (57) inside the reactor (5) to heat the tube array (57), the raw gas introduced into the tube array (57) contacts with the catalyst to promote the mixing reaction of methanol, and under the action of the catalyst, the hydrogen and the carbon dioxide undergo a chemical reaction in the reactor (5), and the generated methanol is discharged to the outside; S6: Methanol Purification The methanol obtained in step S5 is purified, and after the crude methanol enters the distillation tower (10), it is heated for evaporation and condensed for reflux to separate the methanol from other components, thereby obtaining a high-purity methanol product.

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