Mobile hydrogen-carbon methanation system and methanol manufacturing method

Abstract

The invention provides a mobile hydrogen-carbon methanation system and a methanol manufacturing method. The mobile hydrogen-carbon methanation system comprises a vehicle body, a water electrolysis unit, a carbon capture unit, a gas mixing unit and a methanol synthesis unit, the vehicle body has a container; the electrolyzed water unit is arranged on one side, close to the vehicle head, in the container; the carbon capture unit is arranged in the container; the gas mixing unit is respectively connected with the output end of the electrolyzed water unit and the output end of the carbon capture unit; the methanol synthesis unit is arranged on the side, away from the vehicle head, in the container, and the input end of the methanol synthesis unit communicates with the output end of the gas mixing unit. According to the movable hydrogen-carbon methanation system, the whole system can move along with the vehicle body and is convenient to transport and move, the vehicle body can be moved to an area with more carbon dioxide emission for carbon dioxide collection, carbon emission is reduced, no transport pipe needs to be additionally set up, the manufacturing cost is reduced, and the construction period is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of methanol preparation, and specifically relates to a mobile hydrogen-carbon methanolization system and a methanol manufacturing method. Background Art

[0002] As the scale of global chemical production expands, the carbon dioxide emitted by chemical production continues to increase. The challenges posed by the increase in carbon dioxide to energy security, ecological environment and climate change are becoming increasingly prominent. In order to reduce carbon dioxide emissions from chemical production, it is necessary to take emission reduction measures, such as using clean energy, improving energy efficiency and developing carbon capture and storage technology. Carbon capture and storage technology uses methanol and other hydrogen storage molecules to store hydrogen in the form of compounds to achieve the purpose of stable hydrogen delivery. Methanol is generally prepared by hydrogenation of carbon dioxide. In the process of preparing methanol, carbon dioxide is converted as a raw material, achieving the effect of utilizing carbon dioxide and reducing carbon dioxide emissions.

[0003] However, due to the limitation of thermodynamic equilibrium, the equilibrium conversion rate of carbon dioxide is low, only 20% to 30%, resulting in low methanol yield. In addition, the existing methanol production system is built at a preset location and methanol is transported by transport vehicles. The methanol production system cannot be moved and pipelines need to be set up for carbon dioxide collection, which increases the cost of carbon dioxide collection and methanol transportation. Summary of the invention

[0004] The embodiments of the present invention provide a mobile hydrogen-carbon methanolization system and a methanol production method, aiming to solve the technical problem in the prior art that the methanol system is fixed in position, which increases the collection cost and transportation cost.

[0005] To achieve the above object, the technical solution adopted by the present invention is: In a first aspect, a mobile hydrogen-carbon methanolization system is provided, comprising: The vehicle body has a container, a single side of the container is provided with an opening and closing door, and the bottom of the inner cavity of the container is provided with a smoke channel, and the smoke channel is used for connecting and transporting smoke; The water electrolysis unit is arranged on one side of the container close to the front of the vehicle; A carbon capture unit is disposed in the container, wherein an input end of the carbon capture unit is in communication with the flue gas channel; a gas mixing unit, which is disposed inside the container and is connected to an output end of the water electrolysis unit and an output end of the carbon capture unit respectively; and The methanol synthesis unit is arranged at a side of the container away from the front of the vehicle, and the input end of the methanol synthesis unit is connected to the output end of the gas mixing unit.

[0006] In combination with the first aspect, in a possible implementation, a methanol storage tank is further provided at one end of the container away from the front of the vehicle, and the methanol storage tank is connected to an output end of the methanol synthesis unit.

[0007] In combination with the first aspect, in a possible implementation, the water electrolysis unit includes a first water pump, an electrolytic cell, a separation tank, a first flash tank and a hydrogen pipe connected in sequence, and also includes a second water pump; the water inlet end of the first water pump is connected to a water source, the gas outlet end of the hydrogen pipe is connected to the gas mixing unit, the water inlet end of the second water pump is connected to the first flash tank, and the water outlet end of the second water pump is connected to the water inlet end of the electrolytic cell.

[0008] In combination with the first aspect, in a possible implementation, the water electrolysis unit also includes a second flash tank and a gas storage tank connected in sequence, the separation tank has two outlets, one of which is connected to the first flash tank, and the other is connected to the second flash tank, the gas storage tank is used to store oxygen, and the bottom of the second flash tank is connected to the water inlet end of the second water pump.

[0009] In combination with the first aspect, in a possible implementation, the carbon capture unit includes an absorption tower, a third water pump, a heater, a desorption tower, a first condenser, a first reflux tank, a first cooler, and a third flash tank that are sequentially connected along the flue gas flow direction; the input end of the absorption tower is connected to the flue gas channel, the absorption tower contains a solvent that can react with carbon dioxide, the desorption tower is used to purify carbon dioxide, and the top of the third flash tank is connected to the gas mixing unit; A first reflux pipe is provided between the first reflux tank and the analytical tower; The carbon capture unit further includes a first circulation pipe, both ends of which are connected to the analytical tower respectively, and a reboiler is disposed on the first circulation pipe.

[0010] In combination with the first aspect, in a possible implementation, a solvent recovery pipe is connected between the analytical tower and the absorption tower, and a delivery pump, a second cooler, and a second condenser are sequentially arranged on the solvent recovery pipe along the solvent flow direction; a solution replenishment tank is arranged between the second cooler and the second condenser; The bottom of the third flash tank is also communicated with the solvent recovery pipe between the delivery pump and the second cooler.

[0011] In combination with the first aspect, in a possible implementation, the methanol synthesis unit includes a synthesis unit and a refining unit connected in sequence; The synthesis unit comprises a first preheater, a synthesizer, a third cooler, a fourth cooler, a fifth cooler, a fourth flash tank and a fifth flash tank which are connected in sequence; the air inlet end of the preheater is connected to the air outlet end of the gas mixing unit; A flow pipe is provided between the fourth flash tank and the air inlet end of the preheater, and a second preheater is provided on the flow pipe; a compressor is connected to the top of the fifth flash tank, the compressor is connected to the flow pipe, and a connection port is located upstream of the second preheater; the third cooler is also connected to the first preheater, and the fourth cooler is also connected to the second preheater; The refining unit comprises a refining tower, an inlet end of the refining tower is communicated with an outlet end of the fifth flash tank, and a methanol transport pipe is provided at the bottom of the refining tower.

[0012] In combination with the first aspect, in a possible implementation, the refining unit also includes a third condenser, a second reflux tank and a reflux pump, and the refining tower, the third condenser, the second reflux tank and the reflux pump form a circulation passage; the second reflux tank is also respectively connected to a waste water pipe and a waste gas tank, the waste gas tank is used to collect waste gas, and the waste water pipe is used to discharge waste water.

[0013] In combination with the first aspect, in a possible implementation, the gas mixing unit includes a first compressor and a second compressor, the input end of the first compressor is connected to the output end of the water electrolysis unit, the input end of the second compressor is connected to the output end of the carbon capture unit, the output end of the first compressor is connected to the output end of the second compressor, and is connected to the input end of the methanol synthesis unit.

[0014] Compared with the prior art, the mobile hydrogen-carbon methanolization system provided by the present invention provides a mobile methanol production system. The water electrolysis unit, the carbon capture unit, the gas mixing unit and the methanol synthesis unit are all assembled in a container, so that the footprint of the methanol production system is reduced, and the entire system can move with the vehicle body, which is convenient for transportation and movement, and increases the flexibility and freedom of use. The vehicle body can be moved to an area with high carbon dioxide emissions to collect carbon dioxide and reduce carbon emissions. There is no need to build additional transportation pipes, which reduces manufacturing costs, shortens the construction period, and is conducive to promotion and use. Multiple units are packaged in a container with high packaging properties. After the high-temperature flue gas is passed into the carbon capture unit, the residual temperature of the flue gas can provide the heat demand of the carbon capture unit in the container, thereby realizing efficient use of thermal energy.

[0015] In a second aspect, a methanol production method is provided, which is implemented based on a mobile hydrogen-carbon methanolization system as described in any one of the possible implementations above, and is characterized by comprising the following steps: S1: Get water from the water source and get flue gas from the air inlet; S2: water source enters the water electrolysis unit and is decomposed into oxygen and hydrogen, flue gas enters the carbon capture unit through the air inlet, and carbon dioxide is purified; S3: mixing hydrogen and carbon dioxide in the gas mixing unit to obtain a mixed gas; S4: the mixed gas is introduced into the methanol synthesis unit to react with the catalyst to generate methanol and wastewater; S5: purifying the wastewater and passing it into the water electrolysis unit.

[0016] Compared with the prior art, the methanol manufacturing method provided by the present invention provides a movable methanol production system. The water electrolysis unit, the carbon capture unit, the gas mixing unit and the methanol synthesis unit are all assembled in a container, so that the area occupied by the methanol production system becomes smaller, and the entire system can move with the vehicle body, which is convenient for transportation and movement, and increases the flexibility and freedom of use. The vehicle body can be moved to an area with high carbon dioxide emissions to collect carbon dioxide, reduce carbon emissions, and no additional transportation pipes need to be built, which reduces the manufacturing cost, shortens the construction period, and is conducive to promotion and use; multiple units are encapsulated in a container, which has high encapsulation. After the high-temperature flue gas is passed into the carbon capture unit, the residual temperature of the flue gas can provide the heat demand for the carbon capture unit in the container, and realize efficient use of heat energy. The generated wastewater is purified and re-enters the water electrolysis unit for use, which improves the utilization rate of water resources and reduces the use cost; the method can purify the carbon dioxide in the flue gas to ensure the quality of the produced methanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of the principle of a mobile hydrogen-carbon methanolization system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a mobile hydrogen-carbon methanolization system used in an embodiment of the present invention; Figure 3 for Figure 2 A schematic diagram of the structure of the water electrolysis unit used in; Figure 4 for Figure 2 A schematic diagram of the structure of the carbon capture unit used in the invention; Figure 5 for Figure 2A schematic structural diagram of the synthesis unit 5 used in; Figure 6 for Figure 2 A schematic diagram of the structure of the refining unit 6 used in; Figure 7 A schematic diagram of the structure of a vehicle body used in an embodiment of the present invention; Figure 8 for Figure 7 Side view of Fig. 9 for Figure 7 Top cross-sectional view of .

[0019] Description of reference numerals: 1. Vehicle body; 11. Container; 12. Gas purification equipment; 2. water electrolysis unit; 21. first water pump; 22. electrolytic cell; 23. separation tank; 24. first flash tank; 25. hydrogen pipe; 26. second water pump; 27. second flash tank; 28. gas storage tank; 3. Carbon capture unit; 31. Absorption tower; 311. Third water pump; 32. Heater; 33. Analysis tower; 331. First circulation pipe; 332. Reboiler; 34. First condenser; 35. First reflux tank; 36. First cooler; 37. Third flash tank; 38. First reflux pipe; 39. Solvent recovery pipe; 391. Delivery pump; 392. Second cooler; 393. Second condenser; 394. Solution replenishment tank; 4. Gas mixing unit; 41. First compressor; 42. Second compressor; 5. Synthesis unit; 51. First preheater; 52. Synthesizer; 53. Third cooler; 54. Fourth cooler; 55. Fifth cooler; 56. Fourth flash tank; 57. Fifth flash tank; 58. Flow pipe; 581. Second preheater; 59. Compressor; 6. Refining unit; 61. Refining tower; 611. Methanol transport pipe; 62. Third condenser; 63. Second reflux tank; 64. Reflux pump; 65. Waste water pipe; 66. Waste gas tank; 7. Methanol storage tank. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] It should be noted that the directions or positional relationships indicated by terms such as “length”, “width”, “height”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “head” and “tail” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the invention.

[0022] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0024] Please also read Figures 1 to 9 , the mobile hydrogen-carbon methanolization system provided by the present invention is now described. The mobile hydrogen-carbon methanolization system includes a vehicle body 1, a water electrolysis unit 2, a carbon capture unit 3, a gas mixing unit 4 and a methanol synthesis unit. The vehicle body 1 has a container 11, and an opening and closing door is provided on one side of the container 11. A flue gas channel is provided at the bottom of the inner cavity of the container 11, and the flue gas channel is used to transport flue gas; the water electrolysis unit 2 is arranged on a side close to the front of the vehicle in the container 11; the carbon capture unit 3 is arranged in the container 11, and the input end of the carbon capture unit 3 is connected to the flue gas channel; the gas mixing unit 4 is arranged inside the container 11, and the gas mixing unit 4 is connected to the output end of the water electrolysis unit 2 and the output end of the carbon capture unit 3 respectively; the methanol synthesis unit is arranged on a side away from the front of the vehicle in the container 11, and the input end of the methanol synthesis unit is connected to the output end of the gas mixing unit 4.

[0025] It should be noted that the vehicle body 1 can be powered by methanol, and a methanol-powered vehicle is selected, which does not require additional power, thereby reducing energy consumption and realizing the integration of in-situ hydrogen production and methanol production.

[0026] It should be noted that the vehicle body 1 has an opening on one side of the opening and closing door, and the staff can enter through the opening to repair or replace the equipment, which increases the convenience of repair.

[0027] It should be noted that the methanol synthesis unit is also connected to a water purification unit located in the plant, and the water purification unit is connected to the water electrolysis unit 2. The water purification unit includes a water purifier, which filters waste water and various used water, and passes the filtered water into the water electrolysis unit 2 for electrolysis, thereby improving the utilization rate of water resources.

[0028] The working principle of the present application is that after the vehicle body 1 moves to the designated position, the flue gas enters the carbon capture unit 3 from the flue gas channel, the carbon capture unit 3 purifies the carbon dioxide in the flue gas, and at the same time the water electrolysis unit 2 decomposes the water from the water source to produce hydrogen and oxygen, the hydrogen and carbon dioxide are mixed in the gas mixing unit 4, and react in the methanol synthesis unit, and finally methanol and wastewater are generated. After the wastewater is purified, it re-enters the water electrolysis unit 2 for water replenishment.

[0029] Compared with the prior art, the mobile hydrogen-carbon methanolization system provided in this embodiment provides a mobile methanol production system. The water electrolysis unit 2, the carbon capture unit 3, the gas mixing unit 4 and the methanol synthesis unit are all assembled in the container 11, so that the footprint of the methanol production system is reduced, and the entire system can move with the vehicle body 1, which is convenient for transportation and movement, and increases the flexibility and freedom of use. The vehicle body 1 can be moved to an area with high carbon dioxide emissions to collect carbon dioxide and reduce carbon emissions. There is no need to build additional transportation pipes, which reduces manufacturing costs, shortens the construction period, and is conducive to promotion and use. Multiple units are packaged in the container 11 with high packaging properties. After the high-temperature flue gas is passed into the carbon capture unit 3, the residual heat of the flue gas can provide the heat demand for the carbon capture unit 3 in the container 11, thereby preheating each device, improving the conversion efficiency of carbon dioxide and hydrogen, and realizing efficient utilization of thermal energy.

[0030] In some embodiments, see Figure 7 A methanol storage tank 7 is also provided at one end of the container 11 away from the front of the vehicle, and the methanol storage tank 7 is connected to the output end of the methanol synthesis unit. The methanol storage tank 7 is used to store the produced methanol, which is convenient for transportation or use after collection, and increases the convenience of use. The collection position of methanol is fixed, which is easy to collect and transport.

[0031] During specific implementation, the methanol storage tank 7 may also be connected to a methanol engine to provide power to the vehicle body 1 .

[0032] In some embodiments, a photovoltaic panel is disposed on the upper surface of the container 11 , and the photovoltaic panel collects solar energy and provides electricity to the water electrolysis unit 2 . Solar energy is clean and does not generate additional carbon dioxide consumption.

[0033] In some embodiments, see Figure 2 and Figure 3 The water electrolysis unit 2 includes a first water pump 21, an electrolytic cell 22, a separation tank 23, a first flash tank 24 and a hydrogen pipe 25 which are connected in sequence, and also includes a second water pump 26; the water inlet end of the first water pump 21 is connected to the water source, the gas outlet end of the hydrogen pipe 25 is connected to the gas mixing unit 4, the water inlet end of the second water pump 26 is connected to the first flash tank 24, and the water outlet end of the second water pump 26 is connected to the water inlet end of the electrolytic cell 22.

[0034] In a specific implementation, the electrolytic cell 22 contains an electrolyte, and the electrolyte is a KOH solution with a concentration of 35%.

[0035] In this embodiment, the water source provides water to the decomposition tank 22 through the first water pump 21, and the decomposition tank 22 electrolyzes the water to produce hydrogen and oxygen. The hydrogen and oxygen are separated under the action of the separation tank 23, and the hydrogen enters the first flash tank 24 to separate the water vapor. The purified hydrogen is passed into the hydrogen pipe 25 to enter the gas mixing unit 4, and the water removed from the first flash tank 24 is re-passed into the electrolytic tank 22 through the second water pump 26. The water electrolysis unit 2 provided in this embodiment can electrolyze water into hydrogen, purify the hydrogen, and provide high-purity hydrogen to the methanol synthesis unit, which is beneficial to the production quality of methanol; the water vapor mixed in the hydrogen is separated under the action of the first flash tank 24, and reused through the second water pump 26, which improves the utilization rate of water resources and saves water.

[0036] In some embodiments, see Figure 2 and Figure 3 The electrolytic water unit 2 further includes a second flash tank 27 and a gas storage tank 28 which are connected in sequence. The separation tank 23 has two outlets, one of which is connected to the first flash tank 24 and the other is connected to the second flash tank 27. The gas storage tank 28 is used to store oxygen. The bottom of the second flash tank 27 is connected to the water inlet end of the second water pump 26. This embodiment provides a method for processing oxygen. After the oxygen is separated from the hydrogen under the action of the separation tank 23, it is passed into the second flash tank 27. The water vapor mixed in the oxygen is filtered through the second flash tank 27 to obtain high-purity oxygen, which is collected in the oxygen pipe 28 for convenient use or transportation of the oxygen.

[0037] In some embodiments, see Figure 2 and Figure 4The carbon capture unit 3 includes an absorption tower 31, a third water pump 311, a heater 32, a desorption tower 33, a first condenser 34, a first reflux tank 35, a first cooler 36 and a third flash tank 37 which are connected in sequence along the flue gas flow direction; the input end of the absorption tower 31 is connected to the flue gas channel, the absorption tower 31 is filled with a solvent that can react with carbon dioxide, the desorption tower 33 is used to purify carbon dioxide, and the top of the third flash tank 37 is connected to the gas mixing unit 4; a first reflux pipe 38 is provided between the first reflux tank 35 and the desorption tower 33; the carbon capture unit 3 also includes a first circulation pipe 331, both ends of the first circulation pipe 331 are respectively connected to the desorption tower 33, and a reboiler 332 is provided on the first circulation pipe 331.

[0038] In specific implementation, the absorption tower 31 is a tower-shaped structure, and a flue gas inlet is opened on the outer periphery of the bottom surface of the absorption tower 31. The flue gas enters the absorption tower 31 from the flue gas inlet. A spray device is provided on the inner top surface of the absorption tower 31. The spray device can pass a solvent into the absorption tower 31, such as a 35% concentration of ethanolamine (MEA) solution. The ethanolamine solution absorbs carbon dioxide in the flue gas and separates oxygen and nitrogen in the flue gas.

[0039] For specific implementation, see Fig. 9 A gas purification device 12 is provided on the top of the container 11, and the gas purification device 12 is connected to the top exhaust port of the absorption tower 31 to perform evolution treatment on the exhausted gas (nitrogen, oxygen and waste gas) to prevent the gas from being directly discharged into the air and causing air pollution.

[0040] This embodiment provides an embodiment of the carbon capture unit 3. After the flue gas enters the absorption tower 31, the carbon dioxide in the flue gas is absorbed by the solvent, and enters the analysis tower 33 after passing through the third water pump 311 and the heater 32. The analysis tower 33 precipitates the carbon dioxide from the solution. After cooling by the first condenser 34, carbon dioxide with a purity of 99.7% is obtained, thereby improving the quality of the carbon dioxide. After the carbon dioxide is processed by the first reflux tank 35, the first cooler 36 and the third flash tank 37, the dry high-purity carbon dioxide enters the gas mixing unit 4 and is mixed with hydrogen.

[0041] The whole process is reasonable and effective. Carbon dioxide is extracted from the flue gas through the absorption tower, and then high-purity carbon dioxide is obtained through the analysis tower, thereby ensuring the production quality of methanol. The first reflux pipe 38 can pass the solution in the first reflux tank 35 back to the analysis tower 33 to maximize the utilization of the solvent and avoid the solution from entering the first cooler 36 with the carbon dioxide. The third flash tank 37 can remove the water vapor mixed in the carbon dioxide to ensure the purity of the carbon dioxide. It is beneficial to improve the production quality of methanol. The first circulation pipe 331 can heat the solution in the analysis tower 33 through the reboiler 32 to ensure that the reaction in the analysis tower is at a suitable temperature.

[0042] It should be noted that the waste heat provided by the high-temperature flue gas meets the heat demand of the reboiler 32, and the container 11 is closed during use to reduce the heat loss of the flue gas.

[0043] In some embodiments, see Figure 4 A solvent recovery pipe 39 is connected between the analysis tower 33 and the absorption tower 31, and a delivery pump 391, a second cooler 392 and a second condenser 393 are arranged on the solvent recovery pipe 39 in sequence along the solvent flow direction; a solution replenishment tank 394 is arranged between the second cooler 392 and the second condenser 393; the bottom of the third flash tank 37 is also connected to the solvent recovery pipe 39 between the delivery pump 391 and the second cooler 392.

[0044] In this embodiment, the solvent recovery pipe 39 is connected to the analytical tower 33 and the absorption tower 31 respectively, so that the solvent in the analytical tower 33 can be returned to the absorption tower 31 for use. The absorption tower 31, the third water pump 311, the heater 32, the analytical tower 33 and the solvent recovery pipe 39 form a circulation path, so that the solvent can be moved continuously, thereby improving the utilization rate of the solvent. The solution replenishment tank 394 can replenish the solvent from the solvent recovery pipe 39 to ensure the normal operation of the absorption tower 31. The entire unit forms a cycle to maximize the utilization rate of resources.

[0045] In some embodiments, see Figure 2 , Figure 5 and Figure 6 The methanol synthesis unit includes a synthesis unit 5 and a refining unit 6 which are connected in sequence; the synthesis unit 5 includes a first preheater 51, a synthesizer 52, a third cooler 53, a fourth cooler 54, a fifth cooler 55, a fourth flash tank 56 and a fifth flash tank 57 which are connected in sequence; the air inlet end of the preheater is connected to the air outlet end of the gas mixing unit 4; a flow pipe 58 is provided between the fourth flash tank 56 and the air inlet end of the preheater, and a second preheater 581 is provided on the flow pipe 58; a compressor 59 is connected to the top of the fifth flash tank 57, the compressor 59 is connected to the flow pipe 58, and the connection port is located upstream of the second preheater 581; the third cooler 53 is also connected to the first preheater 51, and the fourth cooler 54 is also connected to the second preheater 581; the refining unit 6 includes a refining tower 61, the inlet end of the refining tower 61 is connected to the outlet end of the fifth flash tank 57, and the bottom of the refining tower 61 is provided with a methanol transport pipe 611.

[0046] In this embodiment, the methanol synthesis unit is divided into a synthesis unit 5 and a refining unit 6. The methanol is crudely produced in the synthesis unit 5, and the crude methanol is converted into high-purity methanol through the refining unit 6, thereby improving the quality of the methanol.

[0047] It should be noted that the first preheater 51 may be a heat exchanger.

[0048] During specific implementation, the compressor 59 can compress the water vapor to increase the flow rate of the water vapor.

[0049] It should be noted that a catalyst is provided in the synthesizer 52, and the catalyst may be a solid catalyst Cu / ZnO / Al2O3.

[0050] The general working process of the synthesis unit 5 is as follows: hydrogen and carbon dioxide are mixed in a molar ratio of 3:1, heated to 250°C in the first preheater 51, and then enter the synthesizer 52, where a chemical reaction occurs, and the following reaction occurs: CO2+H2=CO+H2O; CO2+3H2=CH3OH+H2O; CO+2H2=CH3OH.

[0051] The reaction product is subjected to triple cooling and condensation, and the raw synthesis gas is recycled, while the liquid crude methanol (including methanol and water) enters the refining tower 61 for purification. 650 kg / h, 99.9 wt% methanol is obtained at the top of the refining tower 61 and sent to the methanol storage tank 7 for storage according to existing standards.

[0052] The synthesis unit 5 and the refining unit 6 provided in this embodiment do not have complicated coordination. A stable reaction occurs in the synthesizer 52. The third cooler 53 can re-introduce the preliminary synthesized product into the synthesizer 52 for reaction, thereby improving the reaction efficiency and reaction progress. The fourth cooler 54 is also connected to the second preheater 581, and the product is heated and then introduced into the synthesizer 52. The reactants are transported back to the synthesizer 52 through the third reactor 53 and the fourth reactor 54, thereby ensuring that hydrogen and carbon dioxide react fully and increasing productivity. The product is cooled by the fifth cooler 55 and then introduced into the fourth flash tank 56 and the fifth flash tank 57, and the remaining impurities are removed, and the crude methanol is sent to the refining tower 61 to complete the preliminary manufacture of methanol. The fourth flash tank 56 and the fifth flash tank 57 can respectively re-introduce water vapor into the synthesizer 52 for reaction, thereby improving the utilization rate of resources.

[0053] During specific implementation, a stop valve is provided between the fourth flash tank 56 and the fifth flash tank 57, so that the fourth flash tank 56 and the fifth flash tank 57 can be cut off by human intervention, thereby increasing the safety of system operation.

[0054] In some embodiments, see Figure 6The refining unit 6 also includes a third condenser 62, a second reflux tank 63 and a reflux pump 64. The refining tower 61, the third condenser 62, the second reflux tank 63 and the reflux pump 64 form a circulation path; the second reflux tank 63 is also connected to a waste water pipe 65 and a waste gas tank 66, respectively. The waste gas tank 66 is used to collect waste gas, and the waste water pipe 65 is used to discharge waste water. The second reflux tank 63 can return the product discharged from the refining tower 61 to the refining tower 61 under the action of the reflux pump 64 to ensure the refining quality of methanol. After the refining is completed, the waste water is discharged through the waste water pipe 65, and the waste gas is collected through the waste gas tank, so that the methanol impurities discharged from the second reflux tank 63 are reduced, thereby improving the production quality of methanol.

[0055] It should be noted that the bottom of the refining tower 61 is also connected to a circulation pipeline, both ends of the circulation pipeline are respectively connected to the refining tower 61, and a reboiler is arranged on the circulation pipeline.

[0056] In the specific implementation, the wastewater is 99.8wt% alcohol-containing wastewater, and the alcohol-containing wastewater is treated by a water purification unit to obtain purified water, which is then introduced into the water electrolysis unit 2 to achieve efficient use of water.

[0057] In some embodiments, see Figure 2 The gas mixing unit 4 includes a first compressor 41 and a second compressor 42. The input end of the first compressor 41 is connected to the output end of the water electrolysis unit 2, and the input end of the second compressor 42 is connected to the output end of the carbon capture unit 3. The output end of the first compressor 41 is connected to the output end of the second compressor 42, and is connected to the input end of the methanol synthesis unit. The first compressor 41 can receive hydrogen and compress the hydrogen, and the second compressor 42 receives carbon dioxide and compresses the carbon dioxide, so that the hydrogen and carbon dioxide entering the synthesizer 52 can be quickly mixed to ensure the mixing quality.

[0058] In specific implementation, the first compressor 41 controls the hydrogen flow rate to 70 Nm 3 / h, hydrogen and carbon dioxide are compressed to 70 bar in a molar ratio of 3:1 to increase the uniformity of gas mixing.

[0059] In a specific implementation, a three-way pipe is arranged between the first compressor 41, the second compressor 42 and the first preheater 51, and the compressed hydrogen and carbon dioxide enter the first preheater 51 through the three-way pipe after contact.

[0060] The following is a specific embodiment used in this application.

[0061] The treatment capacity of industrial waste gas is up to 2000m 3 / h, the main components of flue gas are as follows: 4.4% water vapor, 17.7% carbon dioxide, 58.8% nitrogen and 19.1% oxygen. It is expected to reduce carbon dioxide emissions by about 600m 3 / h. After simulation calculation, the carbon dioxide flow rate of the carbon dioxide absorption device is 25m 3 / h, the content of carbon dioxide in the rich solution formed by MEA exceeds 90%, proving that the capture rate of carbon dioxide reaches more than 90%. The hydrogen production of electrolytic water unit 2 is 70Nm 3 / h, oxygen production is 32Nm 3 / h, the purity of oxygen and hydrogen both reached more than 99.5%, of which oxygen can be stored and sold. The unit hydrogen production energy consumption of electrolyzer 22 is 40.3kWh / kg, which is in line with the actual production level. The carbon dioxide conversion rate of the methanol synthesis unit is more than 30%, reaching the industrial level. In addition, the selectivity of methanol reaches 98%, the output is 650kg / h, and the purity is as high as 99.9wt%.

[0062] Step 1, the present invention produces hydrogen and oxygen through the water electrolysis unit 2, and the required electricity is provided by the green power system, mainly photovoltaic power generation and wind power generation. The electrolysis water source is provided by the first water pump 21, and a 35% KOH solution is used as the electrolyte. The hydrogen and oxygen produced by electrolysis contain water vapor, which are separated by flash evaporation and re-enter the electrolytic cell for electrolysis through the second water pump 26. The hydrogen is mixed with carbon dioxide after being treated by the first compressor 41 and passed into the methanol synthesis unit, and the oxygen is transported to the gas storage tank 28 for storage through the oxygen pipeline.

[0063] Step 2: The carbon capture unit 3 uses a 35% concentration of ethanolamine (MEA) solution to absorb carbon dioxide. The flue gas enters from the bottom of the absorption tower 31, and the ethanolamine solution is sprayed by the spray device at the top of the tower. The rich liquid flowing out of the bottom of the tower is sent to the analysis tower 33 through the heater 32. The top of the analysis tower 33 obtains crude carbon dioxide gas, which has a purity of 99.7% after condensation and water removal; the lean liquid flowing out of the bottom of the analysis tower 33 mainly contains water and MEA solution, and the fresh MEA solution and a small part of the flue gas condensate are sent to the absorption tower 31 for recycling. The generated carbon dioxide is sent to the methanol synthesis unit.

[0064] Step 3: The methanol synthesis unit includes a first preheater 51, a compressor 59, a synthesizer 52 and a refining tower 61. The hydrogen flow rate is 70 Nm 3 / h, and carbon dioxide are compressed to 70 bar in a molar ratio of 3:1, mixed, preheated to 250°C, and passed into the synthesizer 52, and reacted according to CO2+H2=CO+H2O; CO2+3H2=CH3OH+H2O; CO+2H2=CH3OH. The type of synthesizer 52 is a plug flow reactor, and the reaction temperature is set to 264°C and the reaction pressure is 70 bar. The synthesizer 52 contains the commonly used industrial solid catalyst Cu / ZnO / Al2O3, which needs to be replaced regularly. After the reaction product is cooled and condensed, the raw synthesis gas is recycled by the compressor 59, and the liquid crude methanol (including methanol and water) enters the refining tower 61 for purification, and finally 650kg / h, 99.9wt% methanol is obtained at the top of the tower, which is sent to the methanol storage tank 7 for storage according to the existing standards. 99.8wt% alcohol-containing wastewater is obtained at the bottom of the refining tower 61.

[0065] Step 4: The water purification unit located in the factory receives the flue gas condensate and the alcohol-containing wastewater discharged from the bottom of the refining tower 61, and the purified water after water treatment is sent to the electrolytic water unit 2.

[0066] The basic energy consumption of each item is shown in the table below, and the energy efficiency is 51.3%.

[0067] Table 1 Energy consumption and energy efficiency

[0068] Based on the same inventive concept, the present application also provides a methanol production method, which is implemented based on the mobile hydrogen-carbon methanolization system of any one of the above embodiments, and includes the following steps: S1: Get water from the water source and get flue gas from the air inlet; S2: Water enters the water electrolysis unit 2 and is decomposed into oxygen and hydrogen. Flue gas enters the carbon capture unit 3 through the air inlet and is purified into carbon dioxide. S3: mixing hydrogen and carbon dioxide in the gas mixing unit 4 to obtain a mixed gas; S4: The mixed gas is introduced into the methanol synthesis unit to react with the catalyst to generate methanol and wastewater; S5: Purify the wastewater and pass it into the water electrolysis unit 2.

[0069] It should be noted that the water obtained from the water source is purified water. Before work, a pipe is connected from the outside of the carriage 11 to a water tank or a water pipe to provide a portion of water. During the working process, the water source becomes a water purification unit. The water purification unit receives waste water from the refining tower 61 and a portion of condensed water discharged from the analysis tower 33. The water purification unit purifies various waters into purified water, which is then passed into the electrolytic cell 22.

[0070] Compared with the prior art, the methanol manufacturing method provided in this embodiment has the following advantages: the water electrolysis unit 2, the carbon capture unit 3, the gas mixing unit 4 and the methanol synthesis unit are all assembled in the container 11, so that the area occupied by the methanol production system becomes smaller, and the entire system can move with the vehicle body 1, which is convenient for transportation and movement, and increases the flexibility and freedom of use. The vehicle body 1 can be moved to an area with high carbon dioxide emissions to collect carbon dioxide, reduce carbon emissions, and no additional transportation pipes need to be built, which reduces the manufacturing cost, shortens the construction period, and is conducive to promotion and use; multiple units are encapsulated in the container 11, which has high encapsulation. After the high-temperature flue gas is passed into the carbon capture unit 3, the residual temperature of the flue gas can provide the heat demand for the carbon capture unit 3 in the container 11, and realize the efficient use of heat energy. The generated wastewater is purified and re-enters the water electrolysis unit 2 for use, which improves the utilization rate of water resources and reduces the use cost; this method can purify the carbon dioxide in the flue gas to ensure the quality of the produced methanol.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A mobile hydrogen-carbon methanolization system, characterized in that: include: The vehicle body has a container, wherein a single side of the container is provided with an opening and closing door, and a smoke passage is provided at the bottom of the inner cavity of the container, wherein the smoke passage is used to transport smoke; The water electrolysis unit is arranged on one side of the container close to the front of the vehicle; A carbon capture unit is disposed in the container, wherein an input end of the carbon capture unit is in communication with the flue gas channel; A gas mixing unit is disposed inside the container, and the gas mixing unit is connected to an output end of the water electrolysis unit and an output end of the carbon capture unit respectively; as well as The methanol synthesis unit is arranged at a side of the container away from the front of the vehicle, and the input end of the methanol synthesis unit is connected to the output end of the gas mixing unit.

2. The mobile hydrogen-carbon methanolization system according to claim 1, characterized in that: A methanol storage tank is also provided at one end of the container away from the front of the vehicle, and the methanol storage tank is connected to the output end of the methanol synthesis unit.

3. The mobile hydrogen-carbon methanolization system according to claim 1, characterized in that: The water electrolysis unit includes a first water pump, an electrolytic cell, a separation tank, a first flash tank and a hydrogen pipe connected in sequence, and also includes a second water pump; the water inlet end of the first water pump is connected to a water source, the gas outlet end of the hydrogen pipe is connected to the gas mixing unit, the water inlet end of the second water pump is connected to the first flash tank, and the water outlet end of the second water pump is connected to the water inlet end of the electrolytic cell.

4. The mobile hydrogen-carbon methanolization system according to claim 3, characterized in that: The water electrolysis unit also includes a second flash tank and a gas storage tank connected in sequence, the separation tank has two outlets, one of which is connected to the first flash tank, and the other is connected to the second flash tank. The gas storage tank is used to store oxygen, and the bottom of the second flash tank is connected to the water inlet end of the second water pump.

5. The mobile hydrogen-carbon methanolization system according to claim 1, characterized in that: The carbon capture unit comprises an absorption tower, a third water pump, a heater, a desorption tower, a first condenser, a first reflux tank, a first cooler and a third flash tank which are sequentially connected along the flue gas flow direction; the input end of the absorption tower is connected to the flue gas channel, the absorption tower contains a solvent that can react with carbon dioxide, the desorption tower is used to purify carbon dioxide, and the top of the third flash tank is connected to the gas mixing unit; A first reflux pipe is provided between the first reflux tank and the analytical tower; The carbon capture unit further includes a first circulation pipe, both ends of which are connected to the analytical tower respectively, and a reboiler is disposed on the first circulation pipe.

6. The mobile hydrogen-carbon methanolization system according to claim 5, characterized in that: A solvent recovery pipe is connected between the analytical tower and the absorption tower, and a delivery pump, a second cooler and a second condenser are arranged on the solvent recovery pipe in sequence along the solvent flow direction; a solution replenishment tank is arranged between the second cooler and the second condenser; The bottom of the third flash tank is also communicated with the solvent recovery pipe between the delivery pump and the second cooler.

7. The mobile hydrogen-carbon methanolization system according to claim 1, characterized in that: The methanol synthesis unit comprises a synthesis unit and a refining unit connected in sequence; The synthesis unit comprises a first preheater, a synthesizer, a third cooler, a fourth cooler, a fifth cooler, a fourth flash tank and a fifth flash tank which are connected in sequence; the air inlet end of the preheater is connected to the air outlet end of the gas mixing unit; A flow pipe is provided between the fourth flash tank and the air inlet end of the preheater, and a second preheater is provided on the flow pipe; a compressor is connected to the top of the fifth flash tank, the compressor is connected to the flow pipe, and a connection port is located upstream of the second preheater; the third cooler is also connected to the first preheater, and the fourth cooler is also connected to the second preheater; The refining unit comprises a refining tower, an inlet end of the refining tower is communicated with an outlet end of the fifth flash tank, and a methanol transport pipe is provided at the bottom of the refining tower.

8. The mobile hydrogen-carbon methanolization system according to claim 7, characterized in that: The refining unit also includes a third condenser, a second reflux tank and a reflux pump. The refining tower, the third condenser, the second reflux tank and the reflux pump form a circulation passage; the second reflux tank is also connected to a waste water pipe and a waste gas tank respectively, the waste gas tank is used to collect waste gas, and the waste water pipe is used to discharge waste water.

9. The mobile hydrogen-carbon methanolization system according to claim 1, characterized in that: The gas mixing unit structure includes a first compressor and a second compressor, the input end of the first compressor is connected to the output end of the water electrolysis unit, the input end of the second compressor is connected to the output end of the carbon capture unit, the output end of the first compressor is connected to the output end of the second compressor, and is connected to the input end of the methanol synthesis unit.

10. A method for producing methanol, based on the mobile hydrogen-carbon methanolization system according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: Get water from the water source and get flue gas from the air inlet; S2: water source enters the water electrolysis unit and is decomposed into oxygen and hydrogen, flue gas enters the carbon capture unit through the air inlet, and carbon dioxide is purified; S3: mixing hydrogen and carbon dioxide in the gas mixing unit to obtain a mixed gas; S4: the mixed gas is introduced into the methanol synthesis unit to react with the catalyst to generate methanol and wastewater; S5: purifying the wastewater and passing it into the water electrolysis unit.

Images