A methanol production system

Abstract

The utility model discloses a kind of methanol production systems, it is related to energy utilization technical field, above-mentioned methanol production system includes first raw material supply device, first raw material supply device is used to provide hydrogen carbon gas, second raw material supply device, second raw material supply device is used to provide hydrogen, mixer, first raw material supply device and second raw material supply device are connected with the import of mixer, and output mixed gas, mixer is used to control the hydrogen carbon proportion of mixed gas, synthetic device, synthetic device is connected with the export of mixer, and mixed gas is made into crude methanol, storage device, storage device is connected with synthetic device, and is used to store crude methanol, rectification device, rectification device is connected with storage device, and is used to promote the purity of crude methanol, by multiple raw material providing source, and under the cooperation of multiple raw material providing source, ensure the stability of synthesis raw material providing, to meet the requirement of chemical plant safe and stable operation can be realized.

Description

Technical Field

[0001] This utility model relates to the field of energy utilization technology, and more specifically, to a methanol production system. Background Technology

[0002] Currently, biomass is coupled with green hydrogen to produce methanol, with biomass gasification as a base, and hydrogen produced by electrolysis of water using new energy sources. Under the premise of the same biomass consumption, the production capacity can be doubled. At the same time, wind and solar resources can be utilized locally, realizing a complete industrial chain of green electricity, green hydrogen, and green methanol. With the iteration of hydrogen production technology, the cost of hydrogen production will decrease, which will offset the disadvantage of future biomass price increases, and the overall economics are controllable.

[0003] However, in the current biomass-coupled green hydrogen to green methanol process, the fluctuations in new energy sources such as wind and solar power cause fluctuations in the supply of hydrogen produced by water electrolysis and green hydrogen. However, chemical production requires as stable an operating condition as possible. At the same time, if the supply of green hydrogen is stabilized entirely through energy storage and hydrogen storage balance, the price of green hydrogen will be high, and the production cost of green methanol will be very high.

[0004] In conclusion, improving the stability of the current biomass-coupled green hydrogen methanol production process is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a methanol production system that adopts multiple channels to supply raw materials and improves the stability of the green hydrogen to methanol production process.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A methanol production system, comprising:

[0008] A first raw material supply device, wherein the first raw material supply device is used to supply hydrogen and carbon gas;

[0009] A second raw material supply device is used to supply hydrogen.

[0010] The mixer has both the first and second raw material supply devices connected to its inlet and outputting mixed gas. The total output gas volumes of the first and second raw material supply devices are complementary, so that the CO2 content in the mixed gas is 2-18% of the total mixed gas volume.

[0011] A synthesis unit, connected to the outlet of the mixer, is used to produce crude methanol from the mixed gas. The synthesis fluctuation frequency of the synthesis unit is ≥4h / time, and the load fluctuation range of the synthesis unit is ≤30% / h.

[0012] A storage device connected to the synthesis device and used to store crude methanol;

[0013] A distillation apparatus, connected to the storage device, is used to improve the purity of crude methanol.

[0014] Furthermore, the second raw material supply device includes a hydrogen production device and a hydrogen storage device. The hydrogen production device is connected to the hydrogen storage device, and the hydrogen storage device is connected to the mixer. The hydrogen supply fluctuation frequency of the hydrogen storage device is ≥4h / time, and the hydrogen supply fluctuation range is ≤40% / h.

[0015] Furthermore, the first raw material supply device includes a biomass gasification and purification device, a conversion device, and a decarbonization device. The biomass gasification and purification device is connected to the conversion device, the conversion device is connected to the decarbonization device, and the decarbonization device is connected to the mixer.

[0016] Furthermore, the decarbonization device includes at least two absorption towers and a regeneration tower. The inlets of the absorption towers are all connected to the conversion device, and the outlets of the absorption towers are respectively connected to the regeneration tower and the mixer.

[0017] Furthermore, the synthesis apparatus of this invention includes a synthesis gas compressor, a heat exchanger, a synthesis tower, a cooler, and a separator. The synthesis gas compressor is connected to the mixer, the heat exchanger is connected to the synthesis tower and the cooler, the cooler is connected to the separator, and the separator is connected to the storage device.

[0018] Furthermore, the synthesis apparatus further includes a steam drum and a circulating gas compressor, wherein the steam drum forms a loop with the synthesis tower, and the circulating gas compressor is connected to the outlet of the separator and the outlet of the synthesis gas compressor, respectively.

[0019] Furthermore, the synthesis apparatus of this invention also includes a hydrogen recovery device, which is connected to the circulating gas compressor and the separator via a pipeline.

[0020] Furthermore, the storage device includes at least two storage tanks, which are respectively connected to the separator and the distillation device.

[0021] Furthermore, the hydrogen-to-carbon ratio of the mixed gas output by the mixer is 2:1.

[0022] Furthermore, in this invention, both the syngas compressor and the circulating gas compressor are centrifugal compressors or reciprocating compressors with stepless adjustment function.

[0023] The methanol production system provided by this utility model is used to prepare green methanol. In use, the production system includes a first raw material supply device, a second raw material supply device, a mixer, a synthesis device, a storage device, and a distillation device. The first raw material supply device provides hydrogen and carbon gas, and the second raw material supply device provides hydrogen gas. Both the first and second raw material supply devices are connected to the mixer. The mixer, synthesis device, storage device, and distillation device are connected sequentially as described above. The mixer controls the hydrogen-carbon ratio in the mixed gas and outputs the mixed gas. The synthesis device produces crude methanol from the mixed gas. The storage device stores the crude methanol. The distillation device improves the purity of the crude methanol. By using multiple raw material supply sources and cooperating with each other, the stability of the raw material supply for synthesis is ensured, thereby meeting the requirements for safe and stable operation of chemical plants. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the production system process provided by this utility model.

[0026] Figure 1 In the accompanying drawings, the reference numerals include:

[0027] 1. First raw material supply unit; 101. Decarbonization unit; 102. Regeneration tower; 103. Absorption tower; 104. Shift conversion unit; 105. Biomass gasification and purification unit; 2. Second raw material supply unit; 201. Hydrogen production unit; 202. Hydrogen storage unit; 3. Mixer; 4. Synthesis unit; 401. Circulating gas compressor; 402. Steam drum; 403. Synthesis gas compressor; 404. Synthesis tower; 405. Hydrogen recovery unit; 406. Heat exchanger; 407. Cooler; 408. Separator; 5. Storage unit; 6. Distillation unit. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] The core of this invention is to provide a methanol production system that uses multiple channels to supply raw materials and improves the stability of the green hydrogen-to-methanol production process.

[0030] Please refer to Figure 1 A methanol production system includes a first raw material supply device 1 for supplying hydrogen and carbon gas, i.e., providing a hydrogen-carbon mixed gas. A second raw material supply device 2 is also provided for supplying hydrogen. Both the first and second raw material supply devices 1 and 2 are connected to the inlet of a mixer 3 and output a mixed gas. The total output gases from the first and second raw material supply devices 1 and 2 are complementary, ensuring that the CO2 content in the mixed gas is 2-18% of the total mixed gas. In other words, the hydrogen-carbon mixed gas provided by the first raw material supply device 1 and the hydrogen provided by the second raw material supply device 2 are thoroughly mixed through the mixer 3 to ensure uniform and complete subsequent reactions. The hydrogen-carbon ratio is controlled by adjusting the supply rates of the first and second raw material supply devices 1 and 2, thereby maintaining stable methanol production. The total output gas of the two components is complementary. That is, when the gas output of the second raw material supply device changes, the gas content output by the first raw material supply device is adjusted accordingly to ensure that the CO2 content in the mixed gas is 2-18% of the total mixed gas. The mixer 3 is equipped with a detector for detecting the hydrogen-carbon ratio. The data detected by the detector is sent to the controller for data analysis. The controller controls the gas ratio supplied by the first raw material supply device 1 and the second raw material supply device 2 according to the analysis results, thereby keeping the entire production line stable. The numerical analysis and adjustment based on the numerical values ​​are mature technologies and will not be elaborated further. The mixer also includes a synthesis device 4, a storage device 5, and a distillation device 6. The synthesis device 4 is connected to the outlet of the mixer 3 and is used to produce crude methanol from the mixed gas. The storage device 5 is connected to the synthesis device 4 and is used to store crude methanol. The distillation device 6 is connected to the storage device 5 and is used to improve the purity of the crude methanol, ultimately producing methanol of the required purity.

[0031] It should be noted that in this embodiment of the invention, electromagnetic valves are installed in the pipelines between the various devices, and flow meters, pressure sensors, and other detection components are set on each pipeline. A controller monitors and integrates the data from each pipeline, and the flow rate of the fluid is controlled by controlling the electromagnetic valves in each pipeline. This method is a mature technology, and the specific implementation will not be elaborated further. Additionally, in this embodiment of the invention, the mixer 3 has two inlets and one outlet, with the outlet located between the two inlets. The two inlets face each other, and are connected to the first raw material supply device 1 and the second raw material supply device 2 via pipelines. Therefore, when gas enters the mixer 3 through the two inlets, it creates a countercurrent, further improving its mixing effect and efficiency.

[0032] In operation, the production system includes a first raw material supply device 1, a second raw material supply device 2, a mixer 3, a synthesis device 4, a storage device 5, and a distillation device 6. The first raw material supply device 1 provides hydrogen and carbon gas, and the second raw material supply device 2 provides hydrogen gas. Both the first raw material supply device 1 and the second raw material supply device 2 are connected to the mixer 3. The mixer 3, the synthesis device 4, the storage device 5, and the distillation device 6 are connected in the above-mentioned order, and a mixed gas is output simultaneously. The mixed gas is synthesized into crude methanol. The storage device 5 is used to store the crude methanol, and the distillation device 6 is used to improve the purity of the crude methanol. By using multiple raw material supply sources and cooperating with each other, the stability of the raw material supply for synthesis is ensured, thereby meeting the requirements for safe and stable operation of chemical plants.

[0033] Please refer to Figure 1 In some embodiments, the first raw material supply device 1 includes a biomass gasification and purification device 105, a conversion device 104, and a decarbonization device 101. The biomass gasification and purification device 105 is connected to the conversion device 104, the conversion device 104 is connected to the decarbonization device 101, and the decarbonization device 101 is connected to the mixer 3. That is, the first raw material supply device 1 uses biomass gasification to produce raw materials (carbon-hydrogen) for methanol production. After the biomass gasification and purification device purifies the synthesis gas produced by biomass gasification, it enters the conversion device 104. In the conversion device 104, carbon monoxide and water vapor react to produce hydrogen and carbon dioxide. Then, the mixed gas of hydrogen and carbon dioxide enters the decarbonization device 101 for decarbonization to adjust the carbon-hydrogen ratio in the mixed gas, thereby meeting the requirements for methanol production.

[0034] Please refer to Figure 1In some embodiments, the second raw material supply device 2 includes a hydrogen production device 201 and a hydrogen storage device 202. The hydrogen production device 201 is connected to the hydrogen storage device 202, and the hydrogen storage device 202 is connected to the mixer 3. In other words, the second raw material supply device 2 uses water electrolysis to produce hydrogen. At the same time, the hydrogen produced by this method enters the hydrogen storage device 202 for storage to ensure that the hydrogen supply of the hydrogen raw material storage device 202 can be stably supplied. The hydrogen supply fluctuation frequency is ≥4h / time, and the hydrogen supply fluctuation range is ≤40% / h.

[0035] In the above embodiments, the electricity used for water electrolysis is supplied by wind and solar power generation, which can utilize wind and solar resources locally and realize the entire industrial chain of green electricity, green hydrogen, and green alcohol. With the iteration of hydrogen production technology, the cost of hydrogen production will decrease, which will offset the disadvantage of future biomass price increases, and the overall economic efficiency is controllable.

[0036] In the above embodiments, the hydrogen supply is adjusted according to the fluctuation of new energy power and the load requirements of the methanol synthesis unit. The frequency of hydrogen supply fluctuation is ≥4h / time, and can be as low as 15min / time. The fluctuation range of hydrogen supply is ≤40% / h. Specifically, the fluctuation frequency of the hydrogen storage unit is at least greater than 4h, and the fluctuation time of each fluctuation can be as low as 15min. The fluctuation range of each fluctuation is less than ≤40% / h, thereby making the load fluctuation range of the synthesis unit ≤30% / h. Therefore, the fluctuation of the system during operation is greatly reduced and the stability of the system operation is improved.

[0037] In the above embodiment, an electromagnetic valve is provided between the hydrogen storage device 202 and the mixer 3. The hydrogen supply is controlled by adjusting the opening of the electromagnetic valve. When the output of upstream renewable energy sources such as wind and solar power increases, the hydrogen production of the hydrogen production device 201 increases, and the increased hydrogen production enters the hydrogen storage device 202 for storage. After the methanol synthesis device 4 has been operating stably for more than 4 hours, the hydrogen supply from the hydrogen storage device 202 is increased based on the hydrogen production of the hydrogen production device 201 and the hydrogen storage capacity of the hydrogen storage device 202. Conversely, when the output of upstream renewable energy sources such as wind and solar power decreases, the hydrogen production of the hydrogen production device 201 decreases, and the insufficient hydrogen is supplemented by the hydrogen storage device 202. This control method can be implemented by a PLC, controller, or control board. This method is a mature technology and will not be elaborated further here. Therefore, this method uses the hydrogen storage device 202 as a buffer device to effectively control the hydrogen produced by renewable energy electrolysis of water, avoiding the impact of renewable energy supply fluctuations on the methanol production line.

[0038] In the above embodiments, the synthesis fluctuation frequency of the synthesis unit 4 is ≥4h / time, and the load fluctuation range of the synthesis unit 4 is ≤30% / h. That is, when the output of the new energy wind and solar power in the second raw material supply unit increases, the hydrogen production corresponding to the water electrolysis hydrogen production unit increases, and the increased hydrogen production enters the hydrogen storage unit for storage. At this time, the synthesis unit will operate stably. After the methanol synthesis unit has been operating stably for more than 4 hours, the hydrogen supply from the hydrogen storage unit is increased, and the increased hydrogen supply is controlled to be ≤40% / h of the original hydrogen supply. During the process of increasing the hydrogen supply, the amount of gas supplied by the first raw material supply unit is reduced simultaneously to control the hydrogen-carbon ratio of the mixed gas. After the adjustment is completed, it continues to operate stably for 4 hours to allow the methanol synthesis unit to adapt to the influence of changes in composition and gas volume on the system, and the automatic adjustment of the system is achieved by repeating the above steps.

[0039] In the above embodiments, the conversion device 104 is set to two operating conditions: 50% and 100% load, which are adjusted according to the hydrogen supply of the hydrogen storage device 202.

[0040] Please refer to Figure 1 In some embodiments, the decarbonization device 101 includes at least two absorption towers 103 and a regeneration tower 102. The inlets of the absorption towers 103 are all connected to the conversion device 104, and the outlets of the absorption towers 103 are respectively connected to the regeneration tower 102 and the mixer 3. That is, two absorption towers 103 are provided, and the two absorption towers 103 also include a regeneration tower 102. The inlets of the absorption towers 103 are all connected to the conversion device 104, and the outlets of the absorption towers 103 are respectively connected to the regeneration tower 102 and the mixer 3 to remove excess carbon dioxide and adjust the hydrogen-carbon ratio of the mixed gas.

[0041] In the above embodiments, the amount of carbon dioxide removed is adjusted according to the hydrogen supply at the outlet of the hydrogen storage device 202, and the hydrogen-carbon ratio [(H2-CO2) / (CO+CO2)] of the mixed gas is controlled to be 2:1; the CO2 content in the syngas after mixing is controlled to be 2~18%.

[0042] In the above embodiment, the two absorption towers 103 operate in parallel. When the hydrogen supply from the hydrogen storage device 202 increases, one absorption tower 103 reduces its load while the other maintains its load. As the hydrogen supply increases, the load of the reduced-load absorption tower 103 drops to a minimum of 50%. If the hydrogen supply continues to increase, the load of the other absorption tower 103 is reduced until its load drops to 50%. If the hydrogen supply continues to decrease, one absorption tower 103 is slowly shut down while the load of the other absorption tower 103 is adjusted synchronously. The hydrogen-to-carbon ratio of the synthesis gas after mixer 3 is controlled to be 2.0, thereby achieving the goal of reducing energy consumption and greatly controlling the production cost of methanol.

[0043] Please refer to Figure 1In some embodiments, the synthesis unit 4 includes a synthesis gas compressor 403, a heat exchanger 406, a synthesis tower 404, a cooler 407, and a separator 408. The synthesis gas compressor 403 is connected to the mixer 3. The heat exchanger 406 is connected to both the synthesis tower 404 and the cooler 407. The cooler 407 is connected to the separator 408. The separator 408 is connected to the storage device 5. Specifically, the mixed synthesis gas enters the synthesis gas compressor 403 for pressurization. The heat exchanger 406 exchanges heat between the mixed gas entering the synthesis unit 4 and the gas exiting the synthesis tower 404, ensuring that the mixed gas entering the synthesis tower 404 meets the temperature requirements. The gas discharged from the synthesis tower 404 passes through the cooler 407 and the separator 408, ultimately forming crude methanol.

[0044] In the above embodiments, the heat exchanger 406 can be a plate heat exchanger 406, and the two inlets of the heat exchanger 406 are respectively connected to one outlet of the synthesis tower 404 and the outlet of the synthesizer compressor. The two outlets of the heat exchanger 406 are respectively connected to the inlet of the synthesis tower 404 and the inlet of the cooler 407. By utilizing the temperature of the raw materials in the system for heat exchange, the energy utilization efficiency is greatly improved and the energy consumption is reduced.

[0045] In the above embodiments, the methanol synthesis fluctuation frequency is ≥4h / time, and can be as low as 15min / time; the load fluctuation range is ≤30% / h; the hydrogen storage device 202 is adjusted according to the load of the methanol synthesis device 4.

[0046] Please refer to Figure 1 In some embodiments, the synthesis apparatus 4 further includes a steam drum 402 and a circulating gas compressor 401. The steam drum 402 forms a loop with the synthesis tower 404. The circulating gas compressor 401 is connected to the outlet of the separator 408 and the synthesis gas compressor 403, respectively. Therefore, the mixed synthesis gas enters the synthesis gas compressor 403 for pressurization. After pressurization, it is mixed with the outlet gas of the circulating gas compressor 401. The mixed synthesis gas undergoes heat exchange through the loop heat exchanger 406 and the outlet gas of the methanol synthesis tower 404, which can further improve the utilization efficiency of the heat of the raw materials themselves and reduce energy consumption.

[0047] In the above embodiments, the synthesis tower 404 is either a tubular type or a spiral wound type.

[0048] Please refer to Figure 1 In some embodiments, the synthesis apparatus 4 further includes a hydrogen recovery device 405, which is connected to the circulating gas compressor 401 and the separator 408 via a pipeline. The hydrogen recovery device 405 is used to recover excess hydrogen and reuse it, further reducing energy waste.

[0049] In the above embodiments, the hydrogen recovery device 405 is either membrane separation or pressure swing adsorption (PSA).

[0050] In the above embodiments, the hydrogen recovery device 405 can be connected to the inlet pipe of the syngas compressor via a pipeline and re-enter the methanol synthesis unit for reuse.

[0051] Please refer to Figure 1 In some embodiments, the storage device 5 includes at least two storage tanks, which are respectively connected to the separator 408 and the distillation device 6. That is, by using two storage tanks to supply the distillation device 6, the production efficiency of methanol purification is more stable and fluctuations are effectively prevented.

[0052] In a specific implementation, when the output of the new energy wind and solar power from the second raw material supply unit 2 increases, the hydrogen production capacity of the hydrogen production unit 201 increases. The increased hydrogen production enters the hydrogen storage unit 202 for storage. After the methanol synthesis unit 4 has been running stably for more than 4 hours, a judgment is made based on the hydrogen production capacity of the hydrogen production unit 201 and the hydrogen storage capacity of the hydrogen storage unit 202. The hydrogen supply from the hydrogen storage unit 202 is then increased, with the increased supply controlled to be ≤ 40% / h of the original supply. During the increase in hydrogen supply, the amount of CO2 removed from the decarbonization unit 101 is simultaneously reduced, and the hydrogen-to-carbon ratio of the mixed gas [(H2-CO2) / (CO+CO2)] is controlled to be 1. After the adjustment is completed, the system is run stably for 4 hours to allow the methanol synthesis unit 4 to adapt to the influence of changes in composition and gas volume on the system. If the output of new energy continues to increase, the above adjustment steps are repeated.

[0053] When the output of the new energy wind and solar power from the second raw material supply unit 2 decreases, the hydrogen production capacity of the hydrogen production unit 201 decreases, and the insufficient hydrogen is supplemented by the hydrogen storage unit 202. After the chemical unit has been operating stably for more than 4 hours, based on the hydrogen production capacity and the storage tank capacity, the hydrogen supply from the hydrogen storage unit 202 is reduced. The reduction in hydrogen supply is controlled to be ≤40% of the original hydrogen supply. During the process of reducing the hydrogen supply, the CO2 removal rate in the decarbonization unit 101 is increased simultaneously, and the hydrogen-to-carbon ratio of the mixed gas [(H2-CO2) / (CO+CO2)] is controlled to be 2:1. After the adjustment is completed, the unit operates stably for 4 hours. If the output of the new energy continues to decrease, the above adjustment steps are repeated.

[0054] Based on the new energy output of the second raw material supply unit 2 and the capacity of the hydrogen storage unit 202, the problem of frequent load fluctuations or inoperability of the methanol synthesis unit 4 caused by fluctuations in new energy sources can be solved by alternating adjustments using the above-mentioned multi-steady-state strategy.

[0055] Meanwhile, a large-capacity methanol tank area is adopted (two crude methanol tanks are set up, with each tank storing at least 48 hours of crude methanol production). Then, the tanks are switched periodically. Before switching, the storage in the tanks is refluxed through an external pump to mix evenly, so as to achieve the purpose of stabilizing the distillation feed and realize the stable operation of the distillation unit 6.

[0056] Optionally, in some embodiments, both the syngas compressor and the recirculating gas compressor are centrifugal compressors or reciprocating compressors with stepless adjustment function.

[0057] Specific embodiments include:

[0058] Taking a 200,000-ton / year biomass-coupled green hydrogen methanol project as an example, the pure biomass methanol production capacity is 100,000 tons / year, and the combined capacity after hydrogenation is 100,000 tons / year; the annual biomass consumption is approximately 525,000 tons, and the new energy capacity is approximately 550MW. Based on calculations, the hydrogen supply range is determined to be 10,000~30,000 Nm3 / h. This project will be used as an example to illustrate the system regulation method for green methanol production.

[0059] In state 1, biomass gasification and purification unit 105 and conversion unit 104 are operating at full load. At this time, the hydrogen supply of hydrogen storage unit 202 is 10,000 Nm3 / h, decarbonization unit 101 is operating at 80% load, methanol synthesis unit 4 is operating at 64.8% load, and methanol production is 130,000 tons / year.

[0060] In state 2, the output of new energy wind and solar power increases, and the hydrogen production capacity of hydrogen production unit 201 increases. If the stable operation time in state 1 does not exceed 4 hours, the increased hydrogen production capacity of hydrogen production unit 201 will be stored in hydrogen storage unit 202. If the stable operation time in state 1 is greater than 4 hours, it will enter state 3.

[0061] State 3: Increase the hydrogen supply at the outlet of hydrogen storage unit 202 to a maximum of 14,000 Nm3 / h; biomass gasification, purification, and conversion unit 104 maintains full-load operation; decarbonization unit 101 operates at 72% load; methanol synthesis unit 4 operates at 71.5% load; methanol production is 143,000 tons / year; maintain State 3 operation for more than 4 hours; if the output of new energy wind and solar power fluctuates slightly, continue operating in State 3; if the output of new energy wind and solar power continues to increase, enter State 4.

[0062] In State 4, increase the hydrogen supply at the outlet of hydrogen storage unit 202, up to a maximum of 19,600 Nm3 / h. Biomass gasification, purification, and conversion unit 104 operates at full load. Decarbonization unit 101 operates at 64% load, and methanol synthesis unit 4 operates at 78.7% load, with a methanol production of 157,000 tons / year. Maintain State 4 operation for at least 4 hours. If the output of new energy wind and solar power fluctuates slightly, continue operating in State 4. If the output of new energy wind and solar power continues to increase, adjust according to the strategies of State 3 and State 4. If the output of new energy wind and solar power decreases, proceed to State 5.

[0063] In State 5, reduce the hydrogen supply at the outlet of hydrogen storage unit 202, which can be reduced to a maximum of 14,000 Nm3 / h. Biomass gasification, purification, and conversion unit 104 remains at full load. Decarbonization unit 101 operates at 72% load, and methanol synthesis unit 4 operates at 71.5% load. At this time, the methanol output is 143,000 tons / year. Maintain State 5 operation for more than 4 hours. If the output of new energy wind and solar power fluctuates little, continue to operate in State 5.

[0064] In other words, the key point of this utility model is that: the first raw material supply device 1 is used to provide hydrogen and carbon gas, and the second raw material supply device 2 is used to provide hydrogen gas. Both the first raw material supply device 1 and the second raw material supply device 2 are connected to the mixer 3. At the same time, the mixer 3, the synthesis device 4, the storage device 5, and the distillation device 6 are connected in the above order. The mixer 3 is used to control the hydrogen and carbon ratio in the mixed gas and output the mixed gas. The synthesis device 5 is used to store the crude methanol. The distillation device 6 is used to improve the purity of the crude methanol. Through multiple raw material supply sources and with the cooperation of multiple raw material supply sources, the stability of the supply of synthesis raw materials is ensured, thereby meeting the requirements for safe and stable operation of chemical plants.

[0065] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0066] The methanol production system provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A methanol production system for preparing green methanol, characterized in that, include: The first raw material supply device (1) is used to supply hydrogen and carbon gas; The second raw material supply device (2) is used to supply hydrogen. The mixer (3) is connected to the inlet of the first raw material supply device (1) and the second raw material supply device (2) and outputs mixed gas. The total output gas of the first raw material supply device (1) and the second raw material supply device (2) is complementary so that the CO2 content in the mixed gas is 2 to 18% of the total mixed gas. Synthesis unit (4), which is connected to the outlet of the mixer (3) to produce crude methanol from the mixed gas, wherein the synthesis fluctuation frequency of the synthesis unit (4) is ≥4h / time and the load fluctuation range of the synthesis unit (4) is ≤30% / h; Storage device (5), which is connected to the synthesis device (4) and is used to store crude methanol; A distillation apparatus (6) is connected to the storage device (5) and is used to improve the purity of crude methanol.

2. The methanol production system according to claim 1, characterized in that, The second raw material supply device (2) includes a hydrogen production device (201) and a hydrogen storage device (202). The hydrogen production device (201) is connected to the hydrogen storage device (202), and the hydrogen storage device (202) is connected to the mixer (3). The hydrogen supply fluctuation frequency of the hydrogen storage device (202) is ≥4h / time, and the hydrogen supply fluctuation range is ≤40% / h.

3. The methanol production system according to claim 1, characterized in that, The first raw material supply device (1) includes a biomass gasification and purification device (105), a conversion device (104), and a decarbonization device (101). The biomass gasification and purification device (105) is connected to the conversion device (104), the conversion device (104) is connected to the decarbonization device (101), and the decarbonization device (101) is connected to the mixer (3).

4. The methanol production system according to claim 3, characterized in that, The decarbonization device (101) includes at least two absorption towers (103) and a regeneration tower (102). The inlets of the absorption towers (103) are all connected to the conversion device (104), and the outlets of the absorption towers (103) are connected to the regeneration tower (102) and the mixer (3), respectively.

5. The methanol production system according to claim 1, characterized in that, The synthesis device (4) includes a synthesis gas compressor (403), a heat exchanger (406), a synthesis tower (404), a cooler (407), and a separator (408). The synthesis gas compressor (403) is connected to the mixer (3). The heat exchanger (406) is connected to the synthesis tower (404) and the cooler (407) respectively. The cooler (407) is connected to the separator (408). The separator (408) is connected to the storage device (5).

6. The methanol production system according to claim 5, characterized in that, The synthesis device (4) further includes a steam drum (402) and a circulating gas compressor (401). The steam drum (402) forms a loop with the synthesis tower (404). The circulating gas compressor (401) is connected to the outlet of the separator (408) and the synthesis gas compressor (403), respectively.

7. The methanol production system according to claim 6, characterized in that, The synthesis apparatus (4) further includes a hydrogen recovery device (405), which is connected by a pipeline to the circulating gas compressor (401) and the separator (408).

8. The methanol production system according to claim 5, characterized in that, The storage device (5) includes at least two storage tanks, which are respectively connected to the separator (408) and the distillation device (6).

9. The methanol production system according to any one of claims 1-8, characterized in that, The hydrogen-to-carbon ratio of the mixed gas output by the mixer (3) is 2:

1.

10. The methanol production system according to any one of claims 5-8, characterized in that, The syngas compressor (403) and the circulating gas compressor (401) both adopt centrifugal compressors or reciprocating compressors with stepless adjustment function.

Images