Flexible methanol synthesis system adapting to new energy volatility and operation method thereof

Abstract

The invention relates to the technical field of new energy, and discloses a flexible methanol synthesis system adapting to new energy volatility and an operation method thereof. The flexible methanol synthesis system comprises: a main compressor, wherein the input end of the main compressor is used for connecting a gas source; a methanol synthesis tower; a gas inlet of the methanol separation device is connected with a gas outlet of the methanol synthesis tower; a gas outlet of the methanol synthesis adjusting tower is connected with a gas inlet of the methanol separation device; the first regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis tower; the second regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis regulating tower; according to the flexible methanol synthesis system, stable work can be guaranteed under the condition that the air inlet load is too large or too small, and frequent starting and stopping of the flexible methanol synthesis system caused by frequent fluctuation of the electric power output power are avoided.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a flexible methanol synthesis system adapting to the volatility of new energy and an operation method thereof. Background Art

[0002] With the rapid growth of the installed capacity of new energy sources such as wind and solar power, the proportion of new energy power connected to the grid continues to increase. However, the grid with lagging planning is simply unable to absorb so much incremental green electricity. Generally, wind and solar power are used to electrolyze water to produce hydrogen, and then the hydrogen is converted into electricity or other secondary energy sources, which can achieve smooth output and large-scale application of wind and solar power. Methanol is an ideal carrier for storing and transporting hydrogen. In related technologies, green hydrogen produced by wind and solar power electrolysis of water is generally used with green CO or CO2 obtained from biomass and carbon capture to synthesize methanol, which can achieve smooth output and large-scale application of wind and solar power.

[0003] However, due to the volatility and intermittent characteristics of new energy, the power output fluctuates frequently, causing the flexible methanol synthesis system to start and stop frequently, making it difficult to operate continuously and stably. Summary of the invention

[0004] In view of this, the present invention provides a flexible methanol synthesis system that adapts to the volatility of new energy, so as to solve the problem in the related art that the frequent fluctuation of power output causes the flexible methanol synthesis system to start and stop frequently, making it difficult to operate continuously and stably.

[0005] In a first aspect, the present invention provides a flexible methanol synthesis system that adapts to the volatility of new energy sources, comprising:

[0006] A main compressor, the input end of which is used to connect to the gas source;

[0007] Methanol synthesis tower;

[0008] A methanol separation device, the gas inlet of which is connected to the gas outlet of the methanol synthesis tower;

[0009] A methanol synthesis regulating tower, the gas outlet of which is connected to the gas inlet of the methanol separation device;

[0010] A first regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis tower;

[0011] A second regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis regulating tower;

[0012] The flexible methanol synthesis system has a first state, a second state and a third state. When the flexible methanol synthesis system is in the first state, the first regulating valve is in an open state and the second regulating valve is in a closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve is in a closed state and the second regulating valve is in an open state. When the flexible methanol synthesis system is in the third state, both the first regulating valve and the second regulating valve are in an open state.

[0013] Beneficial effect: During use of the flexible methanol synthesis system that adapts to the volatility of new energy sources in an embodiment of the present invention, when the air intake load of the flexible methanol synthesis system is small, resulting in the heat released by the methanol synthesis reaction being unable to maintain the temperature required for the methanol synthesis tower reaction, the flexible methanol synthesis system can be switched to the second state to work with the help of the methanol synthesis regulating tower and maintain continuous and controllable operation of the methanol synthesis process.

[0014] When the air intake load of the flexible methanol synthesis system is moderate, for example, 50% to 100% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system can be switched to the first state to enable the methanol synthesis tower to operate and synthesize methanol.

[0015] When the air intake load of the flexible methanol synthesis system is large, for example, 100% to 150% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system can be switched to the third state so that the methanol synthesis tower and the methanol synthesis adjustment tower work synchronously, so that the process gas can be fully reacted to generate methanol.

[0016] Therefore, the flexible methanol synthesis system of the embodiment of the invention of the present application can ensure stable operation when the intake load is too large or too small, can avoid frequent start and stop of the flexible methanol synthesis system due to frequent fluctuations in the power output power, and ensure continuous and stable operation of the flexible methanol synthesis system.

[0017] In an optional embodiment, the maximum air inlet load of the methanol synthesis tower is defined as n1, the maximum air inlet load of the methanol synthesis adjustment tower is defined as n2, and 10% n1≤n2≤60% n1.

[0018] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0019] A third regulating valve is connected between the gas outlet of the methanol synthesis tower and the gas inlet of the methanol synthesis regulating tower;

[0020] The fourth regulating valve is connected between the gas outlet of the methanol synthesis tower and the gas inlet of the methanol separation device. When the flexible methanol synthesis system is in the first state, the third regulating valve and the fourth regulating valve are in the open state; when the flexible methanol synthesis system is in the second state, the third regulating valve is in the closed state; when the flexible methanol synthesis system is in the third state, the third regulating valve is in the closed state and the fourth regulating valve is in the open state.

[0021] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0022] The circulating compressor and the methanol separation device include a methanol outlet and a circulating outlet, wherein the methanol outlet is used to output methanol, the circulating outlet is connected to the input end of the circulating compressor, and the output end of the circulating compressor is connected to the input end of the first regulating valve and the input end of the second regulating valve.

[0023] In an optional embodiment, the flexible methanol synthesis system further includes:

[0024] A first gas-to-gas heat exchanger, wherein the output end of the first regulating valve is connected to the shell-side inlet of the first gas-to-gas heat exchanger, the shell-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis tower, the gas outlet of the methanol synthesis tower is connected to the tube-side inlet of the first gas-to-gas heat exchanger, and the tube-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0025] The second gas-to-gas heat exchanger, the output end of the second regulating valve is connected to the shell side inlet of the second gas-to-gas heat exchanger, the shell side outlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis regulating tower, the gas outlet of the methanol synthesis regulating tower is connected to the tube side inlet of the second gas-to-gas heat exchanger, and the tube side outlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device.

[0026] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0027] a fifth regulating valve connected between the gas outlet of the methanol synthesis tower and the tube side inlet of the first gas-to-gas heat exchanger; and / or,

[0028] a sixth regulating valve connected between the gas outlet of the methanol synthesis regulating tower and the tube side inlet of the second gas-to-gas heat exchanger; and / or,

[0029] a seventh regulating valve connected between the pipe outlet of the second gas-to-gas heat exchanger and the gas inlet of the methanol separation device; and / or,

[0030] an eighth regulating valve, wherein the input end of the eighth regulating valve is connected to the gas outlet of the methanol synthesis regulating tower, and the output end of the eighth regulating valve is connected to the shell side of the first gas-to-gas heat exchanger;

[0031] A ninth regulating valve, wherein the input end of the ninth regulating valve is connected to the output ends of the first regulating valve and the eighth regulating valve, and the output end of the ninth regulating valve is connected to the shell side inlet of the first gas-to-gas heat exchanger.

[0032] In an optional embodiment, the flexible methanol synthesis system further comprises a first water vapor separator, the water inlet of the first water vapor separator is connected to the boiler feed water pipeline, the steam outlet of the first water vapor separator is connected to the steam pipeline, the methanol synthesis tower is connected to the bottom inlet of the first water vapor separator, and the bottom outlet of the first water vapor separator is connected to the methanol synthesis tower; and / or,

[0033] It also includes a second water vapor separator, the water inlet of the second water vapor separator is connected to the boiler feed water pipeline, the steam outlet of the second water vapor separator is connected to the steam pipeline, the methanol synthesis regulating tower is connected to the bottom inlet of the second water vapor separator, and the bottom outlet of the second water vapor separator is connected to the methanol synthesis regulating tower.

[0034] In an optional embodiment, there are multiple methanol synthesis adjustment towers, and two adjacent methanol synthesis adjustment towers are respectively the first adjustment tower and the second adjustment tower. The gas outlet of the first adjustment tower is connected to the gas inlet of the second adjustment tower through the tenth adjustment valve, and the gas outlet of the second adjustment tower is connected to the gas inlet of the first adjustment tower through the eleventh adjustment valve.

[0035] In a second aspect, the present invention further provides an operation method of a flexible methanol synthesis system that adapts to the volatility of new energy sources, wherein the flexible methanol synthesis system further comprises:

[0036] A main compressor, the input end of which is used to connect to the gas source;

[0037] Methanol synthesis tower;

[0038] A methanol separation device, the gas inlet of which is connected to the gas outlet of the methanol synthesis tower;

[0039] A methanol synthesis regulating tower, the gas outlet of which is connected to the gas inlet of the methanol separation device;

[0040] A first regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis tower;

[0041] A second regulating valve is connected between the output end of the main compressor and the gas inlet of the methanol synthesis regulating tower;

[0042] The flexible methanol synthesis system has a first state, a second state and a third state. When the flexible methanol synthesis system is in the first state, the first regulating valve is in an open state and the second regulating valve is in a closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve is in a closed state and the second regulating valve is in an open state. When the flexible methanol synthesis system is in the third state, both the first regulating valve and the second regulating valve are in an open state.

[0043] The operation methods include:

[0044] Obtaining the intake air load of the flexible methanol synthesis system;

[0045] The flexible methanol synthesis system is controlled to switch between a first state, a second state and a third state according to the intake air load of the flexible methanol synthesis system.

[0046] Beneficial effect: The operating method of the flexible methanol synthesis system of the second aspect of the present invention includes or uses the flexible methanol synthesis system of the first aspect of the present invention, and thus has its beneficial effect, namely, it can ensure stable operation when the intake load is too large or too small, can avoid frequent start and stop of the flexible methanol synthesis system due to frequent fluctuations in the power output power, and ensure continuous and stable operation of the flexible methanol synthesis system.

[0047] In an optional embodiment, the flexible methanol synthesis system further comprises: a second gas-to-gas heat exchanger, the output end of the second regulating valve is connected to the shell-side inlet of the second gas-to-gas heat exchanger, the shell-side outlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis regulating tower, the gas outlet of the methanol synthesis regulating tower is connected to the tube-side inlet of the second gas-to-gas heat exchanger, and the tube-side inlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0048] After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes:

[0049] When the air intake load of the flexible methanol synthesis system is 5% to 30% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the second state, and the process gas is pressurized by the main compressor and enters the shell side of the second gas-to-gas heat exchanger for preheating. After preheating, it enters the methanol synthesis regulating tower to generate methanol. The generated methanol heats the process gas through the tube side of the second gas-to-gas heat exchanger, and then enters the methanol separation device to separate and obtain methanol.

[0050] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0051] A first gas-to-gas heat exchanger, wherein the output end of the first regulating valve is connected to the shell-side inlet of the first gas-to-gas heat exchanger, the shell-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis tower, the gas outlet of the methanol synthesis tower is connected to the tube-side inlet of the first gas-to-gas heat exchanger, and the tube-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0052] A second gas-to-gas heat exchanger, the output end of the second regulating valve is connected to the shell-side inlet of the second gas-to-gas heat exchanger, the shell-side outlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis regulating tower, the gas outlet of the methanol synthesis regulating tower is connected to the tube-side inlet of the second gas-to-gas heat exchanger, and the tube-side inlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0053] After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes:

[0054] When the air intake load of the flexible methanol synthesis system is 30% to 50% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the second state, and the process gas is pressurized by the main compressor and then enters the shell side of the second gas-to-gas heat exchanger for preheating. The preheated process gas enters the methanol synthesis regulating tower to synthesize methanol, and the methanol at the outlet of the tube side of the second gas-to-gas heat exchanger is divided into two paths. One path of methanol is used to heat the process gas through the tube side of the second gas-to-gas heat exchanger, and then enters the methanol separation device to separate and obtain methanol. The second path of methanol enters the methanol synthesis tower to maintain the reaction temperature of the methanol synthesis tower.

[0055] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0056] A first gas-to-gas heat exchanger, wherein the output end of the first regulating valve is connected to the shell-side inlet of the first gas-to-gas heat exchanger, the shell-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis tower, the gas outlet of the methanol synthesis tower is connected to the tube-side inlet of the first gas-to-gas heat exchanger, and the tube-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0057] After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes:

[0058] When the air intake load of the flexible methanol synthesis system is 50% to 100% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the first state, the process gas is pressurized by the main compressor and then enters the shell side of the first gas-to-gas heat exchanger for preheating, and then enters the methanol synthesis tower to generate methanol. The generated methanol heats the process gas through the tube side of the first gas-to-gas heat exchanger, and the methanol at the outlet of the tube side of the first gas-to-gas heat exchanger is divided into two paths, one path of methanol is separated by a methanol separation device to obtain methanol, and the other path of methanol enters the methanol synthesis regulating tower, and further reacts and maintains the reaction temperature in the methanol synthesis regulating tower, and the methanol output from the methanol synthesis regulating tower is input into the methanol separation device to separate and generate methanol.

[0059] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0060] A first gas-to-gas heat exchanger, wherein the output end of the first regulating valve is connected to the shell-side inlet of the first gas-to-gas heat exchanger, the shell-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis tower, the gas outlet of the methanol synthesis tower is connected to the tube-side inlet of the first gas-to-gas heat exchanger, and the tube-side outlet of the first gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0061] A second gas-to-gas heat exchanger, the output end of the second regulating valve is connected to the shell-side inlet of the second gas-to-gas heat exchanger, the shell-side outlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol synthesis regulating tower, the gas outlet of the methanol synthesis regulating tower is connected to the tube-side inlet of the second gas-to-gas heat exchanger, and the tube-side inlet of the second gas-to-gas heat exchanger is connected to the gas inlet of the methanol separation device;

[0062] After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes:

[0063] When the air intake load of the flexible methanol synthesis system is 100% to 150% of the maximum air intake load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the third state, and the process gas is pressurized by the main compressor and then enters into two paths. One path, which accounts for 60% to 100% of the air intake load of the methanol synthesis tower, is preheated through the shell side of the first gas-to-gas heat exchanger and then enters the methanol synthesis tower to synthesize methanol. The methanol synthesized in the methanol synthesis tower enters the methanol separation device after the process gas is heated through the tube side of the first gas-to-gas heat exchanger. The remaining process gas is preheated through the shell side of the second gas-to-gas heat exchanger and then enters the methanol synthesis regulating tower to synthesize methanol. The methanol synthesized in the methanol synthesis regulating tower enters the methanol separation device after the process gas is heated through the tube side of the second gas-to-gas heat exchanger.

[0064] In an optional embodiment, the flexible methanol synthesis system further comprises:

[0065] A circulating compressor, the methanol separation device comprises a methanol outlet and a circulating outlet, the methanol outlet is used to output methanol, the circulating outlet is connected to the input end of the circulating compressor, and the output end of the circulating compressor is connected to the input end of the first regulating valve and the input end of the second regulating valve;

[0066] The operation method also includes:

[0067] The outlet of the methanol separation device is divided into two paths. One path of the circulating gas that has not been completely reacted is input to the input end of the circulating compressor through the circulating outlet, and then returns to the methanol synthesis tower and / or the methanol synthesis adjustment tower through the output end of the circulating compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0069] Figure 1 This is a schematic structural diagram of a flexible methanol synthesis system that adapts to the volatility of new energy sources according to an embodiment of the present invention;

[0070] Figure 2 This is a schematic structural diagram of a flexible methanol synthesis system that adapts to the volatility of new energy sources according to an embodiment of the present invention, in which there are two methanol synthesis regulating towers.

[0071] Description of reference numerals:

[0072] 1. Main compressor;

[0073] 2. Methanol synthesis tower;

[0074] 3. Methanol separation unit;

[0075] 4. Methanol synthesis regulating tower;

[0076] 5. First regulating valve; 6. Second regulating valve; 7. Third regulating valve; 8. Fourth regulating valve; 9. Circulation compressor; 10. First gas-to-gas heat exchanger; 11. Second gas-to-gas heat exchanger; 12. Fifth regulating valve; 13. Sixth regulating valve; 14. Seventh regulating valve; 15. Eighth regulating valve; 16. First water-vapor separator; 17. Second water-vapor separator; 18. Desulfurization tank; 19. Ninth regulating valve; 20. Tenth regulating valve; 21. Eleventh regulating valve. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0078] With the rapid growth of wind and solar power and other new energy installed capacity, the proportion of new energy power connected to the grid continues to increase. However, the grid with lagging planning is simply unable to absorb so much incremental green electricity. Hydrogen energy, as a high-quality energy carrier, uses wind and solar power to electrolyze water to produce hydrogen, and then converts hydrogen into electricity or other secondary energy, which can achieve smooth output and large-scale application of wind and solar power. Hydrogen energy is a relatively mature business model for green electricity conversion. Green hydrogen and its derived green alcohol and green ammonia will become the final destination of these massive off-grid green electricity.

[0079] Methanol is an ideal carrier for hydrogen storage and transportation, and has the dual properties of raw materials and fuels, and has a wide range of applications. Using green hydrogen produced by wind and solar power electrolysis water hydrogen production devices and biomass and carbon capture to obtain green CO or CO2 to synthesize green methanol has the advantages of being clean, efficient, and environmentally friendly. It is currently the latest methanol production method and is expected to become the mainstream technology for methanol production in the future.

[0080] However, due to the volatility and intermittent characteristics of new energy, the power output fluctuates frequently, affecting the process of hydrogen production and obtaining carbon sources. The frequent decrease and increase of the intake load brings greater regulation pressure, which will cause the synthesis system to start and stop frequently, making it difficult to operate continuously and stably. The general new energy hydrogen production and green alcohol synthesis process maintains the reaction by increasing grid-connected power and raw material storage facilities. However, this is not a truly flexible system. In addition, the increase of auxiliary facilities such as energy storage and storage tanks will also bring more investment costs.

[0081] Combine the following Figure 1 to Figure 2 , describing an embodiment of the present invention.

[0082] According to an embodiment of the present invention, on the one hand, a flexible methanol synthesis system that adapts to the volatility of new energy is provided, including a main compressor 1, a methanol synthesis tower 2, a methanol separation device 3, a first regulating valve 5 and a second regulating valve 6. Among them, the input end of the main compressor 1 is used to connect the gas source. The gas inlet of the methanol separation device 3 is connected to the gas outlet of the methanol synthesis tower 2. The gas outlet of the methanol synthesis regulating tower 4 is connected to the gas inlet of the methanol separation device 3. The first regulating valve 5 is connected between the output end of the main compressor 1 and the gas inlet of the methanol synthesis tower 2. The second regulating valve 6 is connected between the output end of the main compressor 1 and the gas inlet of the methanol synthesis regulating tower 4;

[0083] The flexible methanol synthesis system has a first state, a second state and a third state. When the flexible methanol synthesis system is in the first state, the first regulating valve 5 is in an open state and the second regulating valve 6 is in a closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve 5 is in a closed state and the second regulating valve 6 is in an open state. When the flexible methanol synthesis system is in the third state, both the first regulating valve 5 and the second regulating valve 6 are in an open state.

[0084] During use of the flexible methanol synthesis system of an embodiment of the present invention, when the air intake load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum air intake load of the methanol synthesis tower 2, the heat released by the methanol synthesis reaction cannot maintain the temperature required for the reaction of the methanol synthesis tower 2. The flexible methanol synthesis system can be switched to the second state to work with the help of the methanol synthesis regulating tower 4 and maintain continuous and controllable operation of the methanol synthesis process.

[0085] When the intake load of the flexible methanol synthesis system is moderate, for example, 50% to 100% of the maximum intake load of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the first state to enable the methanol synthesis tower 2 to operate and synthesize methanol.

[0086] When the air intake load of the flexible methanol synthesis system is large, for example, 100% to 150% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the third state so that the methanol synthesis tower 2 and the methanol synthesis adjustment tower 4 work synchronously, so that the process gas can be fully reacted to generate methanol.

[0087] Therefore, the flexible methanol synthesis system of the embodiment of the invention of the present application can ensure stable operation when the intake load is too large or too small, can avoid frequent start and stop of the flexible methanol synthesis system due to frequent fluctuations in the power output power, and ensure continuous and stable operation of the flexible methanol synthesis system.

[0088] The methanol synthesis regulating tower 4 is a methanol synthesis tower with a maximum air intake load of 10% to 60% of that of the methanol regulating tower. Since the maximum air intake load of the methanol synthesis regulating tower 4 itself is relatively small, when the air intake load of the flexible methanol synthesis system is relatively small, resulting in the heat released by the methanol synthesis reaction being unable to maintain the temperature required for the reaction of the methanol synthesis tower 2, the methanol synthesis regulating tower 4 can work normally and ensure the continuous and stable operation of the flexible methanol synthesis system.

[0089] In the embodiment of the present application, the process gas is H2 produced by a new energy hydrogen production device and CO or CO2 obtained by carbon capture and biomass.

[0090] In one embodiment, the maximum air intake load of the methanol synthesis tower 2 is defined as n1, the maximum air intake load of the methanol synthesis adjustment tower 4 is defined as n2, and 10% n1≤n2≤60% n1.

[0091] When the maximum air intake load of the methanol synthesis regulating tower 4 is within the above range, the methanol synthesis regulating tower 4 can work normally when the air intake load of the flexible methanol synthesis system is small, resulting in the heat released by the methanol synthesis reaction being unable to maintain the temperature required for the reaction of the methanol synthesis tower 2, and ensure the continuous and stable operation of the flexible methanol synthesis system.

[0092] In a preferred embodiment, 30% n1≤n2≤50% n1.

[0093] In one embodiment, the flexible methanol synthesis system further includes a third regulating valve 7 and a fourth regulating valve 8. The third regulating valve 7 is connected between the gas outlet of the methanol synthesis tower 2 and the gas inlet of the methanol synthesis regulating tower 4. The fourth regulating valve 8 is connected between the gas outlet of the methanol synthesis tower 2 and the gas inlet of the methanol separation device 3. When the flexible methanol synthesis system is in the first state, the third regulating valve 7 and the fourth regulating valve 8 are in the open state; when the flexible methanol synthesis system is in the second state, the third regulating valve 7 is in the closed state; when the flexible methanol synthesis system is in the third state, the third regulating valve 7 is in the closed state and the fourth regulating valve 8 is in the open state.

[0094] By such arrangement, when the air intake load of the flexible methanol synthesis system is moderate, for example, 50% to 100% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the first state, at which time 10% to 50% of the methanol produced by the methanol synthesis tower 2 can be input into the methanol synthesis regulating tower 4 through the third regulating valve 7 and further reacted, and the remaining methanol can be introduced into the methanol separation device 3 and separated to obtain crude methanol. The methanol separation device 3 can be connected to the methanol rectification section to rectify the prepared crude methanol.

[0095] Therefore, in the flexible methanol synthesis system of the present application, about 40% of the crude methanol synthesized by the methanol synthesis tower 2 can enter the methanol synthesis adjustment tower 4 again and further react, which can increase the net value of alcohol by about 2.9%.

[0096] When the air intake load of the flexible methanol synthesis system is small, resulting in the heat released by the methanol synthesis reaction being unable to maintain the temperature required for the reaction of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the second state, at which time the third regulating valve 7 and the fourth regulating valve 8 can be in a closed state, and the methanol synthesis regulating tower 4 can work and maintain continuous and controllable operation of the methanol synthesis process.

[0097] When the air intake load of the flexible methanol synthesis system is further increased and approaches the temperature required to maintain the reaction of the methanol synthesis tower 2, for example, when it is 30% to 50% of the maximum air intake load of the methanol synthesis tower 2, the third regulating valve 7 can be in a closed state and the fourth regulating valve 8 can be in an open state, so that one path of the methanol synthesized by the methanol synthesis regulating tower 4 can pass through the fourth regulating valve 8 and enter the methanol synthesis tower 2 to preheat the methanol synthesis tower 2.

[0098] When the air intake load of the flexible methanol synthesis system is large, for example, 100% to 150% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the third state, at which time the third regulating valve 7 is in a closed state, and the fourth regulating valve 8 is in an open state, and the crude methanol produced by the methanol synthesis tower 2 can be introduced into the methanol separation device 3 through the fourth regulating valve 8 and separated to obtain crude methanol. The methanol synthesized by the methanol synthesis regulating tower 4 is also introduced into the methanol separation device 3 and separated to obtain crude methanol.

[0099] In one embodiment, the flexible methanol synthesis system further includes a circulating compressor 9. The methanol separation device 3 includes a methanol outlet and a circulating outlet, wherein the methanol outlet is used to output methanol, the circulating outlet is connected to the input end of the circulating compressor 9, and the output end of the circulating compressor 9 is connected to the input end of the first regulating valve 5 and the input end of the second regulating valve 6.

[0100] By such an arrangement, the outlet of the methanol separation device 3 can be divided into two paths, one of which is the unreacted circulating gas, which can be compressed by the circulating compressor 9 and enter the next cycle so that the process gas can be fully reacted, and the other path goes to the methanol distillation section.

[0101] In one embodiment, the flexible methanol synthesis system further includes a desulfurization tank 18. After the working gas is compressed by the circulation compressor 9, the sulfur is removed by the desulfurization tank 18 and then divided into two paths, which are output to the input ends of the first regulating valve 5 and the second regulating valve 6 respectively.

[0102] In one embodiment, the flexible methanol synthesis system further includes a first gas-gas heat exchanger 10 and a second gas-gas heat exchanger 11. The output end of the first regulating valve 5 is connected to the shell side inlet of the first gas-gas heat exchanger 10, the shell side outlet of the first gas-gas heat exchanger 10 is connected to the gas inlet of the methanol synthesis tower 2, the gas outlet of the methanol synthesis tower 2 is connected to the tube side inlet of the first gas-gas heat exchanger 10, and the tube side outlet of the first gas-gas heat exchanger 10 is connected to the gas inlet of the methanol separation device 3.

[0103] The output end of the second regulating valve 6 is connected to the shell side inlet of the second gas-to-gas heat exchanger 11, the shell side outlet of the second gas-to-gas heat exchanger 11 is connected to the gas inlet of the methanol synthesis regulating tower 4, the gas outlet of the methanol synthesis regulating tower 4 is connected to the tube side inlet of the second gas-to-gas heat exchanger 11, and the tube side outlet of the second gas-to-gas heat exchanger 11 is connected to the gas inlet of the methanol separation device 3.

[0104] Since the methanol synthesis reaction can release heat, the flexible methanol synthesis system of the embodiment of the present application can preheat the process gas through the heat released by the methanol synthesis reaction, which not only recycles the heat released during the methanol synthesis process, but also ensures the activity of the catalyst, optimizes the reaction conditions, saves energy, improves product quality, and prolongs the life of the catalyst. Among them, the first gas-to-gas heat exchanger 10 and the second gas-to-gas heat exchanger 11 are preferably, but not limited to, shell-and-tube heat exchangers.

[0105] In one embodiment, the flexible methanol synthesis system further includes a fifth regulating valve 12 , a sixth regulating valve 13 , a seventh regulating valve 14 , an eighth regulating valve 15 and a ninth regulating valve 19 .

[0106] The fifth regulating valve 12 is connected between the gas outlet of the methanol synthesis tower 2 and the pipe side inlet of the first gas-to-gas heat exchanger 10 .

[0107] The sixth regulating valve 13 is connected between the gas outlet of the methanol synthesis regulating tower 4 and the pipe side inlet of the second gas-to-gas heat exchanger 11 .

[0108] The seventh regulating valve 14 is connected between the pipe side outlet of the second gas-to-gas heat exchanger 11 and the gas inlet of the methanol separation device 3 .

[0109] The input end of the eighth regulating valve 15 is connected to the gas outlet of the methanol synthesis regulating tower 4 , and the output end of the eighth regulating valve 15 is connected to the shell side of the first gas-to-gas heat exchanger 10 .

[0110] An input end of the ninth regulating valve 19 is connected to output ends of the first regulating valve 5 and the eighth regulating valve 15 , and an output end of the ninth regulating valve 19 is connected to a shell-side inlet of the first gas-to-gas heat exchanger 10 .

[0111] When the intake load of the flexible methanol synthesis system is close to the minimum load during the operation of the methanol synthesis tower 2, for example, 30% to 50% of the maximum intake load of the methanol synthesis tower 2, the third regulating valve 7 is set in a closed circuit, and the first regulating valve 5, the second regulating valve 6, the fourth regulating valve 8, the fifth regulating valve 12, the sixth regulating valve 13, the seventh regulating valve 14, the eighth regulating valve 15 and the ninth regulating valve 19 are set in an open circuit.

[0112] Through such an arrangement, the methanol synthesized by the methanol synthesis regulating tower 4 can be introduced into the methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat the methanol synthesis tower 2 to maintain the reaction temperature in the methanol synthesis tower 2, ensuring that when the air intake load of the flexible methanol synthesis system is increased to more than 50%, the methanol synthesis tower 2 can start working immediately, thereby improving the methanol synthesis efficiency of the flexible methanol synthesis system.

[0113] In one embodiment, the flexible methanol synthesis system also includes a first water vapor separator 16, a water inlet of the first water vapor separator 16 is connected to a boiler feed water pipeline, a steam outlet of the first water vapor separator 16 is connected to a steam pipeline, a methanol synthesis tower 2 is connected to a bottom inlet of the first water vapor separator 16, and a bottom outlet of the first water vapor separator 16 is connected to a methanol synthesis tower 2.

[0114] The boiler feed water pipeline can supply water to the first water vapor separator 16, and the methanol synthesis tower 2 can provide heat to the first water vapor separator 16 to evaporate the water in the first water vapor separator 16 into steam. The steam can be passed into the steam pipeline to recycle the heat released during the methanol synthesis process.

[0115] The water inlet of the second water vapor separator 17 is connected to the boiler feed water pipeline, the steam outlet of the second water vapor separator 17 is connected to the steam pipeline, the methanol synthesis regulating tower 4 is connected to the bottom inlet of the second water vapor separator 17, and the bottom outlet of the second water vapor separator 17 is connected to the methanol synthesis regulating tower 4.

[0116] The boiler feed water pipeline can supply water to the second water vapor separator 17, and the methanol synthesis regulating tower 4 can provide heat to the second water vapor separator 17 to evaporate the water in the second water vapor separator 17 into steam. The steam can be passed into the steam pipeline to recycle the heat released during the methanol synthesis process.

[0117] The methanol synthesis tower 2 has multiple adjustment towers, and two adjacent methanol synthesis adjustment towers 4 are respectively the first adjustment tower and the second adjustment tower. The gas outlet of the first adjustment tower is connected to the gas inlet of the second adjustment tower through the tenth adjustment valve 20, and the gas outlet of the second adjustment tower is connected to the gas inlet of the first adjustment tower through the eleventh adjustment valve 21.

[0118] The number of methanol synthesis regulating towers 4 can be selected to be one or more. When the number of methanol synthesis regulating towers 4 is multiple, the maximum air intake load of the next-stage methanol synthesis regulating tower 4 is 30% to 50% of the maximum air intake load of the previous-stage methanol synthesis regulating tower 4, and so on.

[0119] According to an embodiment of the present invention, on the other hand, a method for operating a flexible methanol synthesis system that adapts to the volatility of new energy is also provided, wherein the flexible methanol synthesis system can be selected as the flexible methanol synthesis system that adapts to the volatility of new energy provided by the first aspect of the present invention.

[0120] The operation method of the flexible methanol synthesis system of the present invention comprises step S1 and step S2:

[0121] Step S1: obtaining the intake load of the flexible methanol synthesis system;

[0122] Step S2: controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system.

[0123] In one embodiment, step S2 further includes:

[0124] When the air intake load of the flexible methanol synthesis system is 5% to 30% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the second state, and the process gas is pressurized by the main compressor 1 and enters the shell side of the second gas-to-gas heat exchanger 11 for preheating. After preheating, it enters the methanol synthesis regulating tower 4 to generate methanol. The generated methanol heats the process gas through the tube side of the second gas-to-gas heat exchanger 11, and then enters the methanol separation device 3 to separate and obtain methanol.

[0125] When the air intake load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum air intake load of the methanol synthesis tower 2, and the heat released by the methanol synthesis reaction is unable to maintain the required reaction temperature of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the second state to work with the aid of the methanol synthesis regulating tower 4 and maintain continuous and controllable operation of the methanol synthesis process.

[0126] Specifically, during this operation, the third regulating valve 7 , the fourth regulating valve 8 , the fifth regulating valve 12 , the eighth regulating valve 15 , and the ninth regulating valve 19 are set in a closed circuit.

[0127] In one embodiment, after step S2, the method further includes:

[0128] When the air intake load of the flexible methanol synthesis system is 30% to 50% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the second state, and the process gas is pressurized by the main compressor 1 and then enters the shell side of the second gas-to-gas heat exchanger 11 for preheating. The preheated process gas enters the methanol synthesis regulating tower 4 to synthesize methanol. The methanol at the outlet of the tube side of the second gas-to-gas heat exchanger 11 is divided into two paths. One path of methanol is used to heat the process gas through the tube side of the second gas-to-gas heat exchanger 11, and then enters the methanol separation device 3 to separate and obtain methanol. The second path of methanol enters the methanol synthesis tower 2 to maintain the reaction temperature of the methanol synthesis tower 2.

[0129] Through such an arrangement, the methanol synthesized by the methanol synthesis regulating tower 4 can be introduced into the methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat the methanol synthesis tower 2 to maintain the reaction temperature in the methanol synthesis tower 2, ensuring that when the air intake load of the flexible methanol synthesis system is increased to more than 50%, the methanol synthesis tower 2 can start working immediately, thereby improving the methanol synthesis efficiency of the flexible methanol synthesis system.

[0130] During this operation, the third regulating valve 7 is set in a closed circuit, and the first regulating valve 5, the second regulating valve 6, the fourth regulating valve 8, the fifth regulating valve 12, the sixth regulating valve 13, the seventh regulating valve 14, the eighth regulating valve 15 and the ninth regulating valve 19 are set in an open circuit.

[0131] In one embodiment, after step S2, the method further includes:

[0132] When the air intake load of the flexible methanol synthesis system is 50% to 100% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the first state, and the process gas is pressurized by the main compressor 1 and then enters the shell side of the first gas-to-gas heat exchanger 10 for preheating. After preheating, the process gas enters the methanol synthesis tower 2 to generate methanol. The generated methanol heats the process gas through the tube side of the first gas-to-gas heat exchanger 10. The methanol at the outlet of the tube side of the first gas-to-gas heat exchanger 10 is divided into two paths. One path of methanol is separated by the methanol separation device 3 to obtain methanol, and the other path of methanol enters the methanol synthesis regulating tower 4 to further react and maintain the reaction temperature in the methanol synthesis regulating tower 4. The methanol output from the methanol synthesis regulating tower 4 is input into the methanol separation device 3 to separate and generate methanol.

[0133] When the inlet load of the flexible methanol synthesis system is moderate, for example, 50% to 100% of the maximum inlet load of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the first state, at which time 10% to 50% of the methanol produced by the methanol synthesis tower 2 can be input into the methanol synthesis regulating tower 4 through the third regulating valve 7 and further reacted, and the remaining methanol can be introduced into the methanol separation device 3 and separated to obtain crude methanol. The methanol separation device 3 can be connected to the methanol distillation section to distill the prepared crude methanol.

[0134] Therefore, in the flexible methanol synthesis system of the present application, about 40% of the crude methanol synthesized by the methanol synthesis tower 2 can enter the methanol synthesis adjustment tower 4 again and further react, which can increase the net value of alcohol by about 2.9%.

[0135] During this operation, the first regulating valve 5 , the ninth regulating valve 19 , the fifth regulating valve 12 , the fourth regulating valve 8 , the third regulating valve 7 , the sixth regulating valve 13 , and the seventh regulating valve 14 are set in an open circuit, and the eighth regulating valve 15 and the second regulating valve 6 are set in a closed circuit.

[0136] In one embodiment, step S2 further includes:

[0137] When the air intake load of the flexible methanol synthesis system is 100% to 150% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the third state, and the process gas is pressurized by the main compressor 1 and then enters into two paths. One path, which accounts for 60% to 100% of the air intake load of the methanol synthesis tower 2, is preheated through the shell side of the first gas-to-gas heat exchanger 10 and then enters the methanol synthesis tower 2 to synthesize methanol. The methanol synthesized in the methanol synthesis tower 2 enters the methanol separation device 3 after the process gas is heated through the tube side of the first gas-to-gas heat exchanger 10. The remaining process gas is preheated through the shell side of the second gas-to-gas heat exchanger 11 and then enters the methanol synthesis regulating tower 4 to synthesize methanol. The methanol synthesized in the methanol synthesis regulating tower 4 enters the methanol separation device 3 after the process gas is heated through the tube side of the second gas-to-gas heat exchanger 11.

[0138] When the intake air load of the flexible methanol synthesis system is large, the flexible methanol synthesis system can be switched to the third state, and the crude methanol produced by the methanol synthesis tower 2 can be introduced into the methanol separation device 3 through the fourth regulating valve 8 and separated to obtain crude methanol. The methanol synthesized by the methanol synthesis regulating tower 4 is also introduced into the methanol separation device 3 and separated to obtain crude methanol.

[0139] During this operation, the first regulating valve 5, the ninth regulating valve 19, the fifth regulating valve 12, the fourth regulating valve 8, the second regulating valve 6, the sixth regulating valve 13 and the seventh regulating valve 14 are in an open circuit state, and the third regulating valve 7 and the eighth regulating valve 15 are in a closed circuit state.

[0140] In one embodiment, the operating method further comprises:

[0141] The outlet of the methanol separation device 3 is divided into two paths. One path of the circulating gas that has not been completely reacted is input to the input end of the circulating compressor 9 through the circulating outlet, and then returns to the methanol synthesis tower 2 and / or the methanol synthesis adjustment tower 4 through the output end of the circulating compressor 9.

[0142] By such an arrangement, the outlet of the methanol separation device 3 can be divided into two paths, one of which is the unreacted circulating gas, which can be compressed by the circulating compressor 9 and enter the next cycle so that the process gas can be fully reacted, and the other path goes to the methanol distillation section.

[0143] As a convertible embodiment, when the number of methanol synthesis regulating towers 4 is two, the two methanol synthesis regulating towers 4 are defined as a first regulating tower and a second regulating tower. The gas outlet of the first regulating tower is connected to the gas inlet of the second regulating tower through the tenth regulating valve 20, and the gas outlet of the second regulating tower is connected to the gas inlet of the first regulating tower through the eleventh regulating valve 21.

[0144] like Figure 2As shown, the gas inlet of each methanol synthesis tower 2 is connected to the shell side outlet of a second gas-to-gas heat exchanger 11, and the gas outlet of each methanol synthesis tower 2 is connected to the tube side inlet of a second gas-to-gas heat exchanger 11. Preferably, each second gas-to-gas heat exchanger 11 is connected to a second water vapor separator 17.

[0145] At this time, the operation mode of the flexible methanol synthesis system includes:

[0146] Step S1: obtaining the intake load of the flexible methanol synthesis system;

[0147] Step S2: controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system.

[0148] After step S2, it also includes: when the air intake load of the flexible methanol synthesis system is 5% to 30% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the second state, the process gas is pressurized by the main compressor 1 and enters the shell side of the second gas-to-gas heat exchanger 11 for preheating, and then enters the first regulating tower to generate methanol. The generated methanol heats the process gas through the tube side of the second gas-to-gas heat exchanger 11, and then is divided into two paths, one path enters the methanol separation device 3 through the seventh regulating valve 14 to separate and obtain methanol, and the other path enters the gas inlet of the second regulating tower through the tenth regulating valve 20, and reacts again in the second regulating tower. After the reaction is completed, it enters the methanol separation device 3 through the seventh regulating valve 14 to separate and obtain methanol.

[0149] When the air intake load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum air intake load of the methanol synthesis tower 2, and the heat released by the methanol synthesis reaction is unable to maintain the required reaction temperature of the methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the second state to work with the aid of the methanol synthesis regulating tower 4 and maintain continuous and controllable operation of the methanol synthesis process.

[0150] On this basis, about 40% of the crude methanol synthesized in the first adjustment tower can enter the second adjustment tower again and further react, which can increase the net value of alcohol by about 2.9%.

[0151] When the air intake load of the flexible methanol synthesis system is 30% to 50% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the second state, and the process gas is pressurized by the main compressor 1 and enters the shell side of the second gas-to-gas heat exchanger 11 for preheating. The preheated process gas enters the first regulating tower to synthesize methanol, and the methanol at the outlet of the tube side of the second gas-to-gas heat exchanger 11 is divided into two paths. One path of methanol is used to heat the process gas through the tube side of the second gas-to-gas heat exchanger 11, and then enters the methanol separation device 3 to separate and obtain methanol. The second path of methanol enters the methanol synthesis tower 2 to maintain the reaction temperature of the methanol synthesis tower 2.

[0152] Through such an arrangement, the methanol synthesized by the methanol synthesis regulating tower 4 can be introduced into the methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat the methanol synthesis tower 2 to maintain the reaction temperature in the methanol synthesis tower 2, ensuring that when the air intake load of the flexible methanol synthesis system is increased to more than 50%, the methanol synthesis tower 2 can start working immediately, thereby improving the methanol synthesis efficiency of the flexible methanol synthesis system.

[0153] During this operation, the third regulating valve 7 is set in a closed circuit, and the first regulating valve 5, the second regulating valve 6, the fourth regulating valve 8, the fifth regulating valve 12, the sixth regulating valve 13, the seventh regulating valve 14, the eighth regulating valve 15 and the ninth regulating valve 19 are set in an open circuit.

[0154] In one embodiment, after step S2, the method further includes:

[0155] When the air intake load of the flexible methanol synthesis system is 50% to 100% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the first state, and the process gas is pressurized by the main compressor 1 and enters the shell side of the first gas-to-gas heat exchanger 10 for preheating. After preheating, it enters the methanol synthesis tower 2 to generate methanol. The generated methanol heats the process gas through the tube side of the first gas-to-gas heat exchanger 10. The methanol at the outlet of the tube side of the first gas-to-gas heat exchanger 10 is divided into two paths. One path of methanol is separated by the methanol separation device 3 to obtain methanol, and the other path of methanol enters the first regulating tower and further reacts and maintains the reaction temperature in the first regulating tower. The methanol output from the first regulating tower is divided into two paths. One path is input into the gas inlet of the second regulating tower through the tenth regulating valve 20 and continues to react in the second regulating tower, and the other path is input into the methanol separation device 3 to separate and produce methanol.

[0156] During this operation, the first regulating valve 5, the ninth regulating valve 19, the fifth regulating valve 12, the fourth regulating valve 8, the third regulating valve 7, the sixth regulating valve 13, the seventh regulating valve 14 and the tenth regulating valve 20 are set in an open circuit, and the eighth regulating valve 15, the second regulating valve 6 and the eleventh regulating valve 21 are set in a closed circuit.

[0157] In one embodiment, step S2 further includes:

[0158] When the air intake load of the flexible methanol synthesis system is 100% to 150% of the maximum air intake load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the third state, and the process gas is pressurized by the main compressor 1 and then enters into three paths. One path, which accounts for 60% to 100% of the air intake load of the methanol synthesis tower 2, is preheated through the shell side of the first gas-to-gas heat exchanger 10 and then enters the methanol synthesis tower 2 to synthesize methanol. The methanol synthesized in the methanol synthesis tower 2 enters the methanol separation device 3 after the process gas is heated through the tube side of the first gas-to-gas heat exchanger 10. 60% to 100% of the remaining process gas is preheated through the shell side of the second gas-to-gas heat exchanger 11 and then enters the first regulating tower to synthesize methanol. The methanol synthesized in the first regulating tower enters the methanol separation device 3 after the process gas is heated through the tube side of the second gas-to-gas heat exchanger 11.

[0159] The remaining process gas is preheated through the shell side of the second gas-to-gas heat exchanger 11 and then enters the second regulating tower. The methanol synthesized in the second regulating tower enters the methanol separation device 3 after the process gas is heated through the tube side of the second gas-to-gas heat exchanger 11 .

[0160] By such arrangement, when the intake air load of the flexible methanol synthesis system is large, the flexible methanol synthesis system can be switched to the third state, and the crude methanol produced by the methanol synthesis tower 2 can be introduced into the methanol separation device 3 through the fourth regulating valve 8 and separated to obtain crude methanol. The methanol synthesized by the methanol synthesis regulating tower 4 is also introduced into the methanol separation device 3 and separated to obtain crude methanol.

[0161] In an embodiment not shown, the present invention may sequentially set up multiple stages of methanol synthesis regulating towers 4, and the operation method may be deduced in the same manner.

[0162] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A flexible methanol synthesis system adapting to the volatility of new energy, characterized in that: include: A main compressor (1), wherein an input end of the main compressor (1) is used to connect to an air source; Methanol synthesis tower (2); A methanol separation device (3), the gas inlet of which is connected to the gas outlet of the methanol synthesis tower (2); A methanol synthesis regulating tower (4), the gas outlet of which is connected to the gas inlet of the methanol separation device (3); A first regulating valve (5) connected between the output end of the main compressor (1) and the gas inlet of the methanol synthesis tower (2); a second regulating valve (6) connected between the output end of the main compressor (1) and the gas inlet of the methanol synthesis regulating tower (4); The flexible methanol synthesis system has a first state, a second state and a third state. When the flexible methanol synthesis system is in the first state, the first regulating valve (5) is in an open state and the second regulating valve (6) is in a closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve (5) is in a closed state and the second regulating valve (6) is in an open state. When the flexible methanol synthesis system is in the third state, both the first regulating valve (5) and the second regulating valve (6) are in an open state.

2. The flexible methanol synthesis system according to claim 1, characterized in that: The maximum air intake load of the methanol synthesis tower (2) is defined as n1, and the maximum air intake load of the methanol synthesis adjustment tower (4) is defined as n2, 10% n1≤n2≤60% n1.

3. The flexible methanol synthesis system according to claim 1, characterized in that: Also includes: a third regulating valve (7), connected between the gas outlet of the methanol synthesis tower (2) and the gas inlet of the methanol synthesis regulating tower (4); The fourth regulating valve (8) is connected between the gas outlet of the methanol synthesis tower (2) and the gas inlet of the methanol separation device (3); when the flexible methanol synthesis system is in the first state, the third regulating valve (7) and the fourth regulating valve (8) are in the open state; when the flexible methanol synthesis system is in the second state, the third regulating valve (7) is in the closed state; when the flexible methanol synthesis system is in the third state, the third regulating valve (7) is in the closed state and the fourth regulating valve (8) is in the open state.

4. The flexible methanol synthesis system according to any one of claims 1 to 3, characterized in that: Also includes: A circulating compressor (9), the methanol separation device (3) comprises a methanol outlet and a circulating outlet, the methanol outlet is used to output methanol, the circulating outlet is connected to the input end of the circulating compressor (9), and the output end of the circulating compressor (9) is connected to the input end of the first regulating valve (5) and the input end of the second regulating valve (6).

5. The flexible methanol synthesis system according to any one of claims 1 to 3, characterized in that: Also includes: A first gas-to-gas heat exchanger (10), wherein the output end of the first regulating valve (5) is connected to the shell-side inlet of the first gas-to-gas heat exchanger (10), the shell-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol synthesis tower (2), the gas outlet of the methanol synthesis tower (2) is connected to the tube-side inlet of the first gas-to-gas heat exchanger (10), and the tube-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol separation device (3); A second gas-to-gas heat exchanger (11), the output end of the second regulating valve (6) is connected to the shell-side inlet of the second gas-to-gas heat exchanger (11), the shell-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis regulating tower (4), the gas outlet of the methanol synthesis regulating tower (4) is connected to the tube-side inlet of the second gas-to-gas heat exchanger (11), and the tube-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3).

6. The flexible methanol synthesis system according to claim 5, characterized in that: Also includes: a fifth regulating valve (12), connected between the gas outlet of the methanol synthesis tower (2) and the tube side inlet of the first gas-to-gas heat exchanger (10); and / or, a sixth regulating valve (13), connected between the gas outlet of the methanol synthesis regulating tower (4) and the tube side inlet of the second gas-to-gas heat exchanger (11); and / or, a seventh regulating valve (14), connected between the pipe outlet of the second gas-to-gas heat exchanger (11) and the gas inlet of the methanol separation device (3); and / or, an eighth regulating valve (15), wherein an input end of the eighth regulating valve (15) is connected to a gas outlet of the methanol synthesis regulating tower (4), and an output end of the eighth regulating valve (15) is connected to a shell side inlet of the first gas-to-gas heat exchanger (10); A ninth regulating valve (19), wherein the input end of the ninth regulating valve (19) is connected to the output ends of the first regulating valve (5) and the eighth regulating valve (15), and the output end of the ninth regulating valve (19) is connected to the shell side inlet of the first gas-to-gas heat exchanger (10).

7. The flexible methanol synthesis system according to claim 1 or 2, characterized in that: It also includes a first steam separator (16), the water inlet of the first steam separator (16) is connected to the boiler feed water pipeline, the steam outlet of the first steam separator (16) is connected to the steam pipeline, the methanol synthesis tower (2) is connected to the bottom inlet of the first steam separator (16), and the bottom outlet of the first steam separator (16) is connected to the methanol synthesis tower (2); and / or, It also includes a second water vapor separator (17), the water inlet of the second water vapor separator (17) is connected to the boiler feed water pipeline, the steam outlet of the second water vapor separator (17) is connected to the steam pipeline, the methanol synthesis regulating tower (4) is connected to the bottom inlet of the second water vapor separator (17), and the bottom outlet of the second water vapor separator (17) is connected to the methanol synthesis regulating tower (4).

8. The flexible methanol synthesis system according to claim 1 or 2, characterized in that: The methanol synthesis tower (2) includes multiple regulating towers, and two adjacent methanol synthesis regulating towers (4) are defined as a first regulating tower and a second regulating tower, respectively. The gas outlet of the first regulating tower is connected to the gas inlet of the second regulating tower via a tenth regulating valve (20), and the gas outlet of the second regulating tower is connected to the gas inlet of the first regulating tower via an eleventh regulating valve (21).

9. An operating method of a flexible methanol synthesis system adapting to the volatility of new energy, characterized in that: The flexible methanol synthesis system comprises: A main compressor (1), wherein an input end of the main compressor (1) is used to connect to an air source; Methanol synthesis tower (2); A methanol separation device (3), the gas inlet of which is connected to the gas outlet of the methanol synthesis tower (2); A methanol synthesis regulating tower (4), the gas outlet of which is connected to the gas inlet of the methanol separation device (3); A first regulating valve (5) connected between the output end of the main compressor (1) and the gas inlet of the methanol synthesis tower (2); a second regulating valve (6) connected between the output end of the main compressor (1) and the gas inlet of the methanol synthesis regulating tower (4); The flexible methanol synthesis system has a first state, a second state and a third state. When the flexible methanol synthesis system is in the first state, the first regulating valve (5) is in an open state and the second regulating valve (6) is in a closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve (5) is in a closed state and the second regulating valve (6) is in an open state. When the flexible methanol synthesis system is in the third state, both the first regulating valve (5) and the second regulating valve (6) are in an open state. The operation method comprises: Obtaining an intake air load of the flexible methanol synthesis system; The flexible methanol synthesis system is controlled to switch between a first state, a second state and a third state according to an intake air load of the flexible methanol synthesis system.

10. The method for operating a flexible methanol synthesis system according to claim 9, characterized in that: The flexible methanol synthesis system also includes: A second gas-to-gas heat exchanger (11), the output end of the second regulating valve (6) is connected to the shell-side inlet of the second gas-to-gas heat exchanger (11), the shell-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis regulating tower (4), the gas outlet of the methanol synthesis regulating tower (4) is connected to the tube-side inlet of the second gas-to-gas heat exchanger (11), and the tube-side inlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3); After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes: When the air intake load of the flexible methanol synthesis system is 5% to 30% of the maximum air intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the second state, the process gas is pressurized by the main compressor (1) and enters the shell side of the second gas-to-gas heat exchanger (11) for preheating, and then enters the methanol synthesis regulating tower (4) to generate methanol. The generated methanol heats the process gas through the tube side of the second gas-to-gas heat exchanger (11), and then enters the methanol separation device (3) to separate and obtain methanol.

11. The method for operating a flexible methanol synthesis system according to claim 9, characterized in that: The flexible methanol synthesis system also includes: A first gas-to-gas heat exchanger (10), wherein the output end of the first regulating valve (5) is connected to the shell-side inlet of the first gas-to-gas heat exchanger (10), the shell-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol synthesis tower (2), the gas outlet of the methanol synthesis tower (2) is connected to the tube-side inlet of the first gas-to-gas heat exchanger (10), and the tube-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol separation device (3); A second gas-to-gas heat exchanger (11), the output end of the second regulating valve (6) is connected to the shell-side inlet of the second gas-to-gas heat exchanger (11), the shell-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis regulating tower (4), the gas outlet of the methanol synthesis regulating tower (4) is connected to the tube-side inlet of the second gas-to-gas heat exchanger (11), and the tube-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3); After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes: When the air intake load of the flexible methanol synthesis system is 30% to 50% of the maximum air intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the second state, the process gas is pressurized by the main compressor (1) and then enters the shell side of the second gas-to-gas heat exchanger (11) for preheating, the preheated process gas enters the methanol synthesis adjustment tower (4) to synthesize methanol, and the methanol at the outlet of the tube side of the second gas-to-gas heat exchanger (11) is divided into two paths, one path of methanol is used to heat the process gas through the tube side of the second gas-to-gas heat exchanger (11), and then enters the methanol separation device (3) to separate and obtain methanol, and the second path of methanol enters the methanol synthesis tower (2) to maintain the reaction temperature of the methanol synthesis tower (2).

12. The method for operating a flexible methanol synthesis system according to claim 9, characterized in that: The flexible methanol synthesis system also includes: A first gas-to-gas heat exchanger (10), wherein the output end of the first regulating valve (5) is connected to the shell-side inlet of the first gas-to-gas heat exchanger (10), the shell-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol synthesis tower (2), the gas outlet of the methanol synthesis tower (2) is connected to the tube-side inlet of the first gas-to-gas heat exchanger (10), and the tube-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol separation device (3); After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes: When the air intake load of the flexible methanol synthesis system is 50% to 100% of the maximum air intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the first state, the process gas is pressurized by the main compressor (1) and then enters the shell side of the first gas-to-gas heat exchanger (10) for preheating, and then enters the methanol synthesis tower (2) to generate methanol. The generated methanol heats the process gas through the tube side of the first gas-to-gas heat exchanger (10), and the methanol at the outlet of the tube side of the first gas-to-gas heat exchanger (10) is divided into two paths, one path of methanol is separated by the methanol separation device (3) to obtain methanol, and the other path of methanol enters the methanol synthesis regulating tower (4) and further reacts to maintain the reaction temperature in the methanol synthesis regulating tower (4). The methanol output from the methanol synthesis regulating tower (4) is input into the methanol separation device (3) to separate and generate methanol.

13. The operating method of the flexible methanol synthesis system according to claim 9, characterized in that: The flexible methanol synthesis system also includes: A first gas-to-gas heat exchanger (10), wherein the output end of the first regulating valve (5) is connected to the shell-side inlet of the first gas-to-gas heat exchanger (10), the shell-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol synthesis tower (2), the gas outlet of the methanol synthesis tower (2) is connected to the tube-side inlet of the first gas-to-gas heat exchanger (10), and the tube-side outlet of the first gas-to-gas heat exchanger (10) is connected to the gas inlet of the methanol separation device (3); A second gas-to-gas heat exchanger (11), the output end of the second regulating valve (6) is connected to the shell-side inlet of the second gas-to-gas heat exchanger (11), the shell-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis regulating tower (4), the gas outlet of the methanol synthesis regulating tower (4) is connected to the tube-side inlet of the second gas-to-gas heat exchanger (11), and the tube-side outlet of the second gas-to-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3); After controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake air load of the flexible methanol synthesis system, the method further includes: When the air intake load of the flexible methanol synthesis system is 100% to 150% of the maximum air intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the third state, and the process gas is pressurized by the main compressor (1) and then enters into two paths. One path, which accounts for 60% to 100% of the air intake load of the methanol synthesis tower (2), is preheated through the shell side of the first gas-to-gas heat exchanger (10) and then enters the methanol synthesis tower (2) to synthesize methanol. The methanol synthesized in the methanol synthesis tower (2) is heated by the tube side of the first gas-to-gas heat exchanger (10) and then enters the methanol separation device (3). The remaining process gas is preheated through the shell side of the second gas-to-gas heat exchanger (11) and then enters the methanol synthesis regulating tower (4) to synthesize methanol. The methanol synthesized in the methanol synthesis regulating tower (4) is heated by the tube side of the second gas-to-gas heat exchanger (11) and then enters the methanol separation device (3).

14. The method for operating a flexible methanol synthesis system according to any one of claims 9 to 13, characterized in that: The flexible methanol synthesis system also includes: a circulating compressor (9), the methanol separation device (3) comprising a methanol outlet and a circulating outlet, the methanol outlet being used to output methanol, the circulating outlet being connected to the input end of the circulating compressor (9), and the output end of the circulating compressor (9) being connected to the input end of the first regulating valve (5) and the input end of the second regulating valve (6); The operation method further comprises: The outlet of the methanol separation device (3) is divided into two paths. One path of the circulating gas that has not been completely reacted is input to the input end of the circulating compressor (9) through the circulating outlet, and then returns to the methanol synthesis tower (2) and / or the methanol synthesis adjustment tower (4) through the output end of the circulating compressor (9).

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