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

Abstract

The present application relates to the technical field of new energy, and discloses a flexible methanol synthesis system suitable for new energy fluctuation and a running method thereof.The flexible methanol synthesis system comprises a main compressor, an input end of the main compressor being used for connecting a gas source; a methanol synthesis tower; a methanol separation device, a gas inlet of the methanol separation device being connected with a gas outlet of the methanol synthesis tower; a methanol synthesis adjustment tower, a gas outlet of the methanol synthesis adjustment tower being connected with a gas inlet of the methanol separation device; a first adjustment valve, being connected between an output end of the main compressor and a gas inlet of the methanol synthesis tower; and a second adjustment valve, being connected between the output end of the main compressor and a gas inlet of the methanol synthesis adjustment tower.The flexible methanol synthesis system can ensure stable work under the condition that the gas load is too large or too small, and can avoid frequent start and stop of the flexible methanol synthesis system caused by frequent fluctuation of the power output.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a flexible methanol synthesis system suitable for new energy fluctuation and a running method thereof. BACKGROUND

[0002] With the rapid growth of wind and solar power installation scale, the proportion of new energy power grid connection continues to increase, but the power grid with lagging planning is unable to accommodate so much incremental green electricity. Generally, hydrogen is prepared by electrolyzing water using wind and solar power, and then the hydrogen is converted into electric energy or other secondary energy, which can realize smooth output and large-scale application of wind and solar power. Methanol is an ideal carrier for hydrogen storage and transportation. In related technologies, green hydrogen produced by electrolyzing water using wind and solar power is used to synthesize methanol with green CO or CO2 obtained by biomass and carbon capture, which can realize smooth output and large-scale application of wind and solar power.

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

[0004] Therefore, the present application provides a flexible methanol synthesis system suitable for new energy fluctuation to solve the problem that the output power fluctuates frequently in related technologies, causing the flexible methanol synthesis system to start and stop frequently, and it is difficult to continuously and stably operate.

[0005] In a first aspect, the present application provides a flexible methanol synthesis system suitable for new energy fluctuation, comprising:

[0006] a main compressor, an input end of the main compressor being connected to a gas source;

[0007] a methanol synthesis tower;

[0008] a methanol separation device, a gas inlet of the methanol separation device being connected to a gas outlet of the methanol synthesis tower;

[0009] a methanol synthesis adjustment tower, a gas outlet of the methanol synthesis adjustment tower being connected to a gas inlet of the methanol separation device;

[0010] a first adjusting valve, connected between an output end of the main compressor and a gas inlet of the methanol synthesis tower;

[0011] a second adjusting valve, connected between the output end of the main compressor and a gas inlet of the methanol synthesis adjustment 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 the open state and the second regulating valve is in the closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve is in the closed state and the second regulating valve is in the 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 the open state.

[0013] Beneficial effects: In the flexible methanol synthesis system of the present invention, which is adapted to the fluctuation of new energy sources, when the intake load of the flexible methanol synthesis system is small and the heat released by the methanol synthesis reaction cannot maintain the temperature required for the methanol synthesis tower reaction, the flexible methanol synthesis system can be switched to a second state to work with the help of the methanol synthesis regulating tower and maintain the continuous and controllable operation of the methanol synthesis process.

[0014] 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, the flexible methanol synthesis system can be switched to the first state so that the methanol synthesis tower can work and synthesize methanol.

[0015] When the inlet gas load of the flexible methanol synthesis system is large, for example, 100% to 150% of the maximum inlet gas 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 regulating tower can work synchronously, thereby allowing the process gas to be fully reacted and methanol to be generated.

[0016] Therefore, the flexible methanol synthesis system of this invention can ensure stable operation under conditions of excessive or insufficient intake load, avoid frequent start-stop of the flexible methanol synthesis system caused by frequent fluctuations in power output, and ensure continuous and stable operation of the flexible methanol synthesis system.

[0017] In one optional implementation, the maximum inlet load of the methanol synthesis tower is defined as n1, and the maximum inlet load of the methanol synthesis regulating tower is defined as n2, where 10%n1≤n2≤60%n1.

[0018] In one optional embodiment, the flexible methanol synthesis system further includes:

[0019] The 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 unit. When the flexible methanol synthesis system is in the first state, the third and fourth regulating valves 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 one optional embodiment, the flexible methanol synthesis system further includes:

[0022] The circulating compressor and methanol separation unit include a methanol outlet and a circulating outlet. The methanol outlet is used to output methanol, and the circulating outlet is connected to the input end of the circulating compressor. 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 one optional embodiment, the flexible methanol synthesis system further includes:

[0024] The output end of the first gas-to-gas heat exchanger 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 unit.

[0025] The output end of the second gas-to-gas heat exchanger 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 unit.

[0026] In one optional embodiment, the flexible methanol synthesis system further includes:

[0027] The fifth regulating valve is 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] The sixth regulating valve is 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] The seventh regulating valve is connected between the tube-side outlet of the second gas-to-gas heat exchanger and the gas inlet of the methanol separator; and / or,

[0030] The eighth regulating valve has its input end connected to the gas outlet of the methanol synthesis regulating tower and its output end connected to the shell side of the first gas-to-gas heat exchanger.

[0031] The ninth regulating valve has its input end connected to the output ends of the first and eighth regulating valves, and its output end connected to the shell-side inlet of the first gas-gas heat exchanger.

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

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

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

[0035] Secondly, the present invention also provides an operation method for a flexible methanol synthesis system adapted to the volatility of new energy sources, wherein the flexible methanol synthesis system further includes:

[0036] The main compressor has its input end connected to the gas source.

[0037] Methanol synthesis tower;

[0038] The methanol separation unit has its gas inlet connected to the gas outlet of the methanol synthesis tower;

[0039] The methanol synthesis regulating tower has its gas outlet connected to the gas inlet of the methanol separation unit.

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

[0041] The 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 the open state and the second regulating valve is in the closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve is in the closed state and the second regulating valve is in the 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 the open state.

[0043] The operation methods include:

[0044] Obtain the inlet air load of the flexible methanol synthesis system;

[0045] The flexible methanol synthesis system is switched between the first, second, and third states based on the intake air load of the flexible methanol synthesis system.

[0046] Beneficial effects: The operation 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 therefore has its beneficial effects, namely, it can ensure stable operation under the condition of excessive or insufficient intake load, can avoid frequent start-up and shutdown of the flexible methanol synthesis system due to frequent fluctuations in power output, and ensures the continuous and stable operation of the flexible methanol synthesis system.

[0047] In one optional embodiment, the flexible methanol synthesis system further includes: a second gas-to-gas heat exchanger, the output end of the second regulating valve being 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 being connected to the gas inlet of the methanol synthesis regulating tower, the gas outlet of the methanol synthesis regulating tower being 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 being connected to the gas inlet of the methanol separation unit.

[0048] After controlling the switching between the first, second, and third states of the flexible methanol synthesis system based on the intake air load of the flexible methanol synthesis system, the following steps are also included:

[0049] When the inlet gas load of the flexible methanol synthesis system is 5% to 30% of the maximum inlet gas load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the second state. 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. 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 unit to separate and obtain methanol.

[0050] In one optional embodiment, the flexible methanol synthesis system further includes:

[0051] The output end of the first gas-to-gas heat exchanger 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 unit.

[0052] The output end of the second gas-to-gas heat exchanger 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 unit.

[0053] After controlling the switching between the first, second, and third states of the flexible methanol synthesis system based on the intake air load of the flexible methanol synthesis system, the following steps are also included:

[0054] When the inlet gas load of the flexible methanol synthesis system is 30% to 50% of the maximum inlet gas load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the second state. The process gas is pressurized by the main compressor and 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. The methanol at the tube side outlet of the second gas-to-gas heat exchanger is divided into two paths. One path of methanol heats the process gas through the tube side of the second gas-to-gas heat exchanger and then enters the methanol separation unit to separate methanol. The second path of methanol enters the methanol synthesis tower to maintain the reaction temperature of the methanol synthesis tower.

[0055] In one optional embodiment, the flexible methanol synthesis system further includes:

[0056] The output end of the first gas-to-gas heat exchanger 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 unit.

[0057] After controlling the switching between the first, second, and third states of the flexible methanol synthesis system based on the intake air load of the flexible methanol synthesis system, the following steps are also included:

[0058] When the inlet gas load of the flexible methanol synthesis system is 50% to 100% of the maximum inlet gas 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 enters the shell side of the first gas-to-gas heat exchanger for preheating. After preheating, it 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. The methanol at the tube side outlet of the first gas-to-gas heat exchanger is divided into two paths. One path of methanol is separated into methanol by a methanol separator, and the other path of methanol enters the methanol synthesis regulating tower for further reaction and to maintain the reaction temperature in the methanol synthesis regulating tower. The methanol output from the methanol synthesis regulating tower is fed into the methanol separator for separation to generate methanol.

[0059] In one optional embodiment, the flexible methanol synthesis system further includes:

[0060] The output end of the first gas-to-gas heat exchanger 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 unit.

[0061] The output end of the second gas-to-gas heat exchanger 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 unit.

[0062] After controlling the switching between the first, second, and third states of the flexible methanol synthesis system based on the intake air load of the flexible methanol synthesis system, the following steps are also included:

[0063] When the inlet load of the flexible methanol synthesis system is 100% to 150% of the maximum inlet load of the methanol synthesis tower, the flexible methanol synthesis system is switched to the third state. The process gas is pressurized by the main compressor and then divided into two streams. One stream, which accounts for 60% to 100% of the inlet load of the methanol synthesis tower, is preheated in 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 is heated by the tube side of the first gas-to-gas heat exchanger and then enters the methanol separation unit. The remaining process gas is preheated in 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 is heated by the tube side of the second gas-to-gas heat exchanger and then enters the methanol separation unit.

[0064] In one optional embodiment, the flexible methanol synthesis system further includes:

[0065] The circulating compressor and methanol separation unit include a methanol outlet and a circulating outlet. The methanol outlet is used to output methanol, and the circulating outlet is connected to the input end of the circulating compressor. 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 execution method also includes:

[0067] The methanol separation unit has two outlets. One outlet is for unreacted circulating gas, which is fed into the input of the circulating compressor and then returned to the methanol synthesis tower and / or the methanol synthesis regulating tower through the output of the circulating compressor. Attached Figure Description

[0068] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0069] Fig. 1 This is a schematic diagram of a flexible methanol synthesis system adapted to the volatility of new energy sources according to an embodiment of the present invention;

[0070] Fig. 2 This is a schematic diagram of a flexible methanol synthesis system adapted to the volatility of new energy sources according to an embodiment of the present invention. The diagram shows two methanol synthesis regulating towers.

[0071] Explanation of reference numerals in the attached figures:

[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. Circulating 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 Implementation

[0077] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0078] With the rapid growth of 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 its lagging planning, is simply unable to absorb such a large amount of incremental green electricity. Hydrogen energy, as a high-quality energy carrier, utilizes wind and solar power to electrolyze water to produce hydrogen, which is then converted into electricity or other secondary energy sources, enabling smooth output and large-scale application of wind and solar power. Hydrogen energy is a relatively mature business model for green electricity conversion, and green hydrogen and its derivatives, green alcohols and green ammonia, will become the final destination for these massive amounts of off-grid green electricity.

[0079] Methanol is an ideal carrier for storing and transporting hydrogen, and it possesses the dual properties of both a feedstock and a fuel, making it widely applicable. Utilizing green hydrogen produced by wind, solar, and water electrolysis plants, combined with biomass and carbon capture to obtain green CO or CO2, and then synthesizing green methanol, offers advantages such as cleanliness, high efficiency, and environmental friendliness. This 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 volatile and intermittent nature of new energy sources, power output fluctuates frequently, affecting hydrogen production and carbon source acquisition processes. Frequent increases and decreases in intake gas load create significant regulatory pressure, leading to frequent start-ups and shutdowns of the synthesis system, making continuous and stable operation difficult. Typical new energy hydrogen production and chlorophyll synthesis processes maintain the reaction by increasing grid-connected power and raw material storage facilities; however, this is not a truly flexible system. Furthermore, the addition of auxiliary facilities such as energy storage and tanks also incurs substantial investment costs.

[0081] The following is combined Figs. 1-2 The following describes embodiments of the present invention.

[0082] According to an embodiment of the present invention, a flexible methanol synthesis system adapted to the fluctuations of new energy sources is provided, comprising a main compressor 1, a methanol synthesis tower 2, a methanol separation unit 3, a first regulating valve 5, and a second regulating valve 6. The input end of the main compressor 1 is connected to a gas source. The inlet of the methanol separation unit 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 unit 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 the open state and the second regulating valve 6 is in the closed state. When the flexible methanol synthesis system is in the second state, the first regulating valve 5 is in the closed state and the second regulating valve 6 is in the 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 the open state.

[0084] In the flexible methanol synthesis system of this embodiment of the invention, when the inlet load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum inlet load of the methanol synthesis tower 2, the heat released by the methanol synthesis reaction cannot maintain the temperature required for the reaction in the methanol synthesis tower 2. In this case, the flexible methanol synthesis system can be switched to a second state so as to work with the help of the methanol synthesis regulating tower 4 and maintain the continuous and controllable operation of the methanol synthesis process.

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

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

[0087] Therefore, the flexible methanol synthesis system of this invention can ensure stable operation under conditions of excessive or insufficient intake load, avoid frequent start-stop of the flexible methanol synthesis system caused by frequent fluctuations in power output, and ensure continuous and stable operation of the flexible methanol synthesis system.

[0088] Among them, methanol synthesis regulating tower 4 is a methanol synthesis tower with a maximum inlet gas load configuration of 10% to 60% of that of the methanol regulating tower. Since the maximum inlet gas load of methanol synthesis regulating tower 4 is relatively small, when the inlet gas load of the flexible methanol synthesis system is small, resulting in the heat released by the methanol synthesis reaction being insufficient to maintain the reaction temperature required by methanol synthesis tower 2, methanol synthesis regulating tower 4 can operate normally and ensure the continuous and stable operation of the flexible methanol synthesis system.

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

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

[0091] When the maximum inlet gas load of methanol synthesis regulating tower 4 is within the above range, methanol synthesis regulating tower 4 can operate normally when the inlet gas 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 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 unit 3. When the flexible methanol synthesis system is in a first state, both the third regulating valve 7 and the fourth regulating valve 8 are open; when the flexible methanol synthesis system is in a second state, the third regulating valve 7 is closed; and when the flexible methanol synthesis system is in a third state, the third regulating valve 7 is closed and the fourth regulating valve 8 is open.

[0094] With this configuration, when the inlet load of the flexible methanol synthesis system is moderate, for example, 50% to 100% of the maximum inlet load of methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the first state. At this time, 10% to 50% of the methanol produced by methanol synthesis tower 2 can be input into methanol synthesis regulating tower 4 through the third regulating valve 7 for further reaction. The remaining methanol can be fed into methanol separation unit 3 and separated to obtain crude methanol. Methanol separation unit 3 can be connected to the methanol distillation section to distill the prepared crude methanol.

[0095] Therefore, in the flexible methanol synthesis system of this application, about 40% of the crude methanol synthesized in methanol synthesis tower 2 can be reintroduced into methanol synthesis regulating tower 4 for further reaction, which can increase the net alcohol value by about 2.9%.

[0096] When the intake load of the flexible methanol synthesis system is low, causing the heat released by the methanol synthesis reaction to be insufficient to maintain the temperature required for the reaction in methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the second state. At this time, the third regulating valve 7 and the fourth regulating valve 8 can be closed, and the methanol synthesis regulating tower 4 can work and maintain the continuous and controllable operation of the methanol synthesis process.

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

[0098] When the inlet load of the flexible methanol synthesis system is large, for example, 100% to 150% of the maximum inlet load of methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the third state. In this state, the third regulating valve 7 is closed, and the fourth regulating valve 8 is open. The crude methanol produced by methanol synthesis tower 2 can be fed into the methanol separation unit 3 through the fourth regulating valve 8 and separated to obtain crude methanol. The methanol synthesized by methanol synthesis regulating tower 4 is also fed into the methanol separation unit 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 unit 3 includes a methanol outlet and a circulating outlet. The methanol outlet is used to output methanol, and the circulating outlet is connected to the input end of the circulating compressor 9. 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] With this setup, the outlet of the methanol separator 3 can be divided into two paths: one 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; 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 circulating compressor 9, it is desulfurized by the desulfurization tank 18 and then divided into two paths, which are respectively output to the input ends of the first regulating valve 5 and the second regulating valve 6.

[0102] In one embodiment, the flexible methanol synthesis system further includes a first gas-to-gas heat exchanger 10 and a second gas-to-gas heat exchanger 11. The output 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 unit 3.

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

[0104] Since the methanol synthesis reaction releases heat, the flexible methanol synthesis system of this application embodiment can preheat the process gas using the heat released by the methanol synthesis reaction. This not only recovers and utilizes the heat released during the methanol synthesis process, but also has positive effects on ensuring catalyst activity, optimizing reaction conditions, saving energy, improving product quality, and extending catalyst life. 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 tube 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 tube inlet of the second gas-to-gas heat exchanger 11.

[0108] The seventh regulating valve 14 is connected between the tube outlet of the second gas-gas heat exchanger 11 and the gas inlet of the methanol separator 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] 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-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 methanol synthesis tower 2, for example, 30% to 50% of the maximum intake load of methanol synthesis tower 2, the third regulating valve 7 is closed, 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 open.

[0112] With this setup, the methanol synthesized in methanol synthesis regulating tower 4 can be fed into methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat methanol synthesis tower 2 to maintain the reaction temperature inside methanol synthesis tower 2. This ensures that when the gas load of the flexible methanol synthesis system increases to more than 50%, 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 further includes a first water-steam separator 16, the inlet of which is connected to a boiler feedwater pipeline, the steam outlet of which is connected to a steam pipeline, the methanol synthesis tower 2 being connected to the bottom inlet of the first water-steam separator 16, and the bottom outlet of which is connected to the methanol synthesis tower 2.

[0114] The boiler feedwater pipeline can supply water to the first water-steam separator 16, and the methanol synthesis tower 2 can provide heat to the first water-steam separator 16 to evaporate the water in the first water-steam separator 16 into steam. The steam can be introduced into the steam pipeline to recover and utilize the heat released during the methanol synthesis process.

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

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

[0117] The methanol synthesis tower 2 consists of multiple regulating towers. Two adjacent methanol synthesis regulating towers 4 are respectively the first regulating tower and the 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.

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

[0119] According to an embodiment of the present invention, in another aspect, a method for operating a flexible methanol synthesis system adapted to the volatility of new energy sources is also provided, wherein the flexible methanol synthesis system can be selected as the flexible methanol synthesis system adapted to the volatility of new energy sources provided in the first aspect of the present invention.

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

[0121] Step S1: Obtain the inlet air load of the flexible methanol synthesis system;

[0122] Step S2: Control the switching of the flexible methanol synthesis system 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 inlet gas load of the flexible methanol synthesis system is 5% to 30% of the maximum inlet gas 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. 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 intake load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum intake load of methanol synthesis tower 2, the heat released by the methanol synthesis reaction cannot maintain the temperature required for the reaction in methanol synthesis tower 2. In this case, the flexible methanol synthesis system can be switched to the second state to operate with the help of methanol synthesis regulating tower 4 and maintain the 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 closed-loop.

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

[0128] When the inlet gas load of the flexible methanol synthesis system is 30% to 50% of the maximum inlet gas 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. The preheated process gas enters the methanol synthesis regulating tower 4 to synthesize methanol. The methanol at the tube side outlet of the second gas-to-gas heat exchanger 11 is divided into two paths. One path of 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 methanol. The second path of methanol enters the methanol synthesis tower 2 to maintain the reaction temperature of the methanol synthesis tower 2.

[0129] With this setup, the methanol synthesized in methanol synthesis regulating tower 4 can be fed into methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat methanol synthesis tower 2 to maintain the reaction temperature inside methanol synthesis tower 2. This ensures that when the gas load of the flexible methanol synthesis system increases to more than 50%, 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 closed, while 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 open.

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

[0132] When the inlet gas load of the flexible methanol synthesis system is 50% to 100% of the maximum inlet gas 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 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 tube side outlet of the first gas-to-gas heat exchanger 10 is divided into two paths. One path of methanol is separated into methanol by the methanol separation device 3, and the other path of methanol enters the methanol synthesis regulating tower 4 for further reaction and to maintain the reaction temperature in the methanol synthesis regulating tower 4. The methanol output from the methanol synthesis regulating tower 4 is fed into the methanol separation device 3 for separation to 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 methanol synthesis tower 2, the flexible methanol synthesis system can be switched to the first state. At this time, 10% to 50% of the methanol produced by methanol synthesis tower 2 can be input into methanol synthesis regulating tower 4 through the third regulating valve 7 for further reaction. The remaining methanol can be fed into methanol separation unit 3 and separated to obtain crude methanol. Methanol separation unit 3 can be connected to the methanol rectification section to rectify the prepared crude methanol.

[0134] Therefore, in the flexible methanol synthesis system of this application, about 40% of the crude methanol synthesized in methanol synthesis tower 2 can be reintroduced into methanol synthesis regulating tower 4 for further reaction, which can increase the net alcohol value 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 to open circuit, while the eighth regulating valve 15 and the second regulating valve 6 are set to closed circuit.

[0136] In one embodiment, step S2 is followed by:

[0137] When the inlet load of the flexible methanol synthesis system is 100% to 150% of the maximum inlet load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the third state. The process gas is pressurized by the main compressor 1 and then divided into two streams. One stream, which accounts for 60% to 100% of the inlet load of the methanol synthesis tower 2, is preheated in 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 unit 3. The remaining process gas is preheated in 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 unit 3.

[0138] When the inlet gas load of the flexible methanol synthesis system is large, the flexible methanol synthesis system can be switched to the third state. The crude methanol produced by methanol synthesis tower 2 can be fed into methanol separation unit 3 through the fourth regulating valve 8 and separated to obtain crude methanol. The methanol synthesized by methanol synthesis regulating tower 4 is also fed into methanol separation unit 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 the open circuit state, while the third regulating valve 7 and the eighth regulating valve 15 are in the closed circuit state.

[0140] In one embodiment, the running method further includes:

[0141] The outlet of the methanol separation unit 3 is divided into two paths. One path is for the unreacted circulating gas to be input to the input end of the circulating compressor 9 through the circulating outlet, and then returned to the methanol synthesis tower 2 and / or the methanol synthesis regulating tower 4 through the output end of the circulating compressor 9.

[0142] With this setup, the outlet of the methanol separator 3 can be divided into two paths: one 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; the other path goes to the methanol distillation section.

[0143] As a possible implementation, when there are two methanol synthesis regulating towers 4, the two methanol synthesis regulating towers 4 are defined as the first regulating tower and the second regulating tower, respectively. 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 Fig. 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] The flexible methanol synthesis system operates in the following modes:

[0146] Step S1: Obtain the inlet air load of the flexible methanol synthesis system;

[0147] Step S2: Control the switching of the flexible methanol synthesis system 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, the process further includes: when the inlet load of the flexible methanol synthesis system is 5% to 30% of the maximum inlet 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. After preheating, it 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 splits into two paths. One path enters the methanol separation device 3 through the seventh regulating valve 14 to separate 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 methanol.

[0149] When the intake load of the flexible methanol synthesis system is small, for example, 10% to 30% of the maximum intake load of methanol synthesis tower 2, the heat released by the methanol synthesis reaction cannot maintain the temperature required for the reaction in methanol synthesis tower 2. In this case, the flexible methanol synthesis system can be switched to the second state to operate with the help of methanol synthesis regulating tower 4 and maintain the continuous and controllable operation of the methanol synthesis process.

[0150] Based on this, about 40% of the crude methanol synthesized in the first regulating tower can be reintroduced into the second regulating tower for further reaction, which can increase the net alcohol value by about 2.9%.

[0151] When the inlet gas load of the flexible methanol synthesis system is 30% to 50% of the maximum inlet gas 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. The preheated process gas enters the first regulating tower to synthesize methanol. The methanol at the tube side outlet of the second gas-to-gas heat exchanger 11 is divided into two paths. One path of 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 methanol. The second path of methanol enters the methanol synthesis tower 2 to maintain the reaction temperature of the methanol synthesis tower 2.

[0152] With this setup, the methanol synthesized in methanol synthesis regulating tower 4 can be fed into methanol synthesis tower 2, so that the heat released during the methanol synthesis process can preheat methanol synthesis tower 2 to maintain the reaction temperature inside methanol synthesis tower 2. This ensures that when the gas load of the flexible methanol synthesis system increases to more than 50%, 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 closed, while 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 open.

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

[0155] When the inlet gas load of the flexible methanol synthesis system is 50% to 100% of the maximum inlet gas 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 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 tube side outlet of the first gas-to-gas heat exchanger 10 is divided into two paths. One path of methanol is separated into methanol by the methanol separator 3, and the other path of methanol enters the first regulating tower for further reaction and to maintain 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. The other path is input into the methanol separator 3 to separate and generate 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 to open circuit, while the eighth regulating valve 15, the second regulating valve 6, and the eleventh regulating valve 21 are set to closed circuit.

[0157] In one embodiment, step S2 is followed by:

[0158] When the inlet load of the flexible methanol synthesis system is 100% to 150% of the maximum inlet load of the methanol synthesis tower 2, the flexible methanol synthesis system is switched to the third state. The process gas is pressurized by the main compressor 1 and then divided into three streams. One stream, which accounts for 60% to 100% of the inlet load of the methanol synthesis tower 2, is preheated in 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 unit 3. The remaining 60% to 100% of the process gas is preheated in 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 is heated by the tube side of the second gas-to-gas heat exchanger 11 and then enters the methanol separation unit 3.

[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 is heated by the tube side of the second gas-to-gas heat exchanger 11 and then enters the methanol separation unit 3.

[0160] With this configuration, when the intake load of the flexible methanol synthesis system is large, the system can be switched to the third state. The crude methanol produced by methanol synthesis tower 2 can then be fed into the methanol separation unit 3 via the fourth regulating valve 8 and separated into crude methanol. The methanol synthesized by methanol synthesis regulating tower 4 is also fed into the methanol separation unit 3 and separated into crude methanol.

[0161] In embodiments not shown, the present invention may sequentially set up multiple methanol synthesis regulating towers 4, and the operation method may be deduced accordingly.

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

Claims

1. A method for operating a flexible methanol synthesis system adapted to fluctuations in new energy, characterized in that, The flexible methanol synthesis system comprises: A main compressor (1), an input end of the main compressor (1) being used for connecting a gas source; A methanol synthesis tower (2); A methanol separation device (3), a gas inlet of the methanol separation device (3) being connected to a gas outlet of the methanol synthesis tower (2); A methanol synthesis adjustment tower (4), a gas outlet of the methanol synthesis adjustment tower (4) being connected to a gas inlet of the methanol separation device (3); A first adjustment valve (5), being connected between an output end of the main compressor (1) and a gas inlet of the methanol synthesis tower (2); A second adjustment valve (6), being connected between the output end of the main compressor (1) and a gas inlet of the methanol synthesis adjustment 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 adjustment valve (5) is in an open state and the second adjustment valve (6) is in a closed state, when the flexible methanol synthesis system is in the second state, the first adjustment valve (5) is in a closed state and the second adjustment valve (6) is in an open state, when the flexible methanol synthesis system is in the third state, the first adjustment valve (5) and the second adjustment valve (6) are both in an open state; The operation method comprises: Obtaining an intake load of the flexible methanol synthesis system; Controlling the flexible methanol synthesis system to switch between the first state, the second state and the third state according to the intake load of the flexible methanol synthesis system; When the intake load of the flexible methanol synthesis system is 5% to 50% of a maximum intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the second state; When the intake load of the flexible methanol synthesis system is 50% to 100% of the maximum intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the first state; When the intake load of the flexible methanol synthesis system is 100% to 150% of the maximum intake load of the methanol synthesis tower (2), the flexible methanol synthesis system is switched to the third state.

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

3. The method for operating the flexible methanol synthesis system according to claim 1, characterized in that, The flexible methanol synthesis system further comprises: The first gas-gas heat exchanger (10), the output end of the first adjusting 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); The second gas-gas heat exchanger (11), the output end of the second adjusting valve (6) is connected to the shell side inlet of the second gas-gas heat exchanger (11), the shell side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis adjustment tower (4), the gas outlet of the methanol synthesis adjustment tower (4) is connected to the tube side inlet of the second gas-gas heat exchanger (11), and the tube side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3); After the flexible methanol synthesis system is switched between the first state, the second state and the third state according to the gas load of the flexible methanol synthesis system, the method further comprises: When the flexible methanol synthesis system's gas load is 30%~50% of the maximum gas load of the methanol synthesis tower (2), the process gas is pressurized by the main compressor (1) and then enters the shell side of the second gas-gas heat exchanger (11) for preheating, and after preheating, enters the methanol synthesis adjustment tower (4) to synthesize methanol, and the methanol at the tube side outlet of the second gas-gas heat exchanger (11) is divided into two paths, one path of the methanol is heated by the tube side of the second gas-gas heat exchanger (11) to heat the process gas, and then enters the methanol separation device (3) to separate and obtain methanol, and the second path of the methanol enters the methanol synthesis tower (2) to maintain the reaction temperature of the methanol synthesis tower (2).

4. The method of claim 1, wherein the flexible methanol synthesis system is operated at a pressure of 100 to 300 bar. 5 The flexible methanol synthesis system further comprises: The first gas-gas heat exchanger (10), the output end of the first adjusting 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); After the flexible methanol synthesis system is switched between the first state, the second state and the third state according to the gas load of the flexible methanol synthesis system, the method further comprises: When the flexible methanol synthesis system is in the first state, the process gas is pressurized by the main compressor (1) and enters the shell side of the first gas-gas heat exchanger (10) for preheating, and then enters the methanol synthesis tower (2) to generate methanol, the generated methanol passes through the tube side of the first gas-gas heat exchanger (10) to heat the process gas, and the methanol at the outlet of the tube side of the first gas-gas heat exchanger (10) is divided into two paths, one path of the methanol is separated by the methanol separation device (3) to obtain methanol, and the other path of the methanol enters the methanol synthesis adjustment tower (4) and further reacts to maintain the reaction temperature in the methanol synthesis adjustment tower (4), and the methanol output from the methanol synthesis adjustment tower (4) is input into the methanol separation device (3) to separate and generate methanol.

5. The method of claim 1, wherein the flexible methanol synthesis system is operated at a pressure of 100 to 300 bar. 5 The flexible methanol synthesis system further comprises: The first gas-gas heat exchanger (10), the output end of the first adjusting 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); The second gas-gas heat exchanger (11), the output end of the second adjusting valve (6) is connected to the shell side inlet of the second gas-gas heat exchanger (11), the shell side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis adjustment tower (4), the gas outlet of the methanol synthesis adjustment tower (4) is connected to the tube side inlet of the second gas-gas heat exchanger (11), and the tube side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3); After the flexible methanol synthesis system is switched between the first state, the second state and the third state according to the gas inlet load of the flexible methanol synthesis system, the method further comprises: When the flexible methanol synthesis system is in the first state, the process gas is pressurized by the main compressor (1) and enters the shell side of the first gas-gas heat exchanger (10) for preheating, and then enters the methanol synthesis tower (2) to generate methanol, the generated methanol passes through the tube side of the first gas-gas heat exchanger (10) to heat the process gas, and the methanol at the outlet of the tube side of the first gas-gas heat exchanger (10) is divided into two paths, one path of the methanol is separated by the methanol separation device (3) to obtain methanol, and the other path of the methanol enters the methanol synthesis adjustment tower (4) and further reacts to maintain the reaction temperature in the methanol synthesis adjustment tower (4), and the methanol output from the methanol synthesis adjustment tower (4) is input into the methanol separation device (3) to separate and generate methanol.

6. The method of claim 1 to 5, wherein, The flexible methanol synthesis system further comprises: a recycle compressor (9), the methanol separation device (3) comprising a methanol outlet for outputting methanol and a recycle outlet connected to an input end of the recycle compressor (9), an output end of the recycle compressor (9) being connected to an input end of the first regulating valve (5) and an input end of the second regulating valve (6); the operation method further comprising: the unreacted recycle gas being input to an input end of the recycle compressor (9) through the recycle outlet and being returned to the methanol synthesis column (2) and / or the methanol synthesis regulating column (4) through an output end of the recycle compressor (9).

7. A flexible methanol synthesis system adapted to accommodate fluctuations in new energy, characterized in that, An operation method suitable for the flexible methanol synthesis system according to any one of claims 1-6, the flexible methanol synthesis system comprising: a main compressor (1), an input end of the main compressor (1) being connected to a gas source; a methanol synthesis column (2); a methanol separation device (3), a gas inlet of the methanol separation device (3) being connected to a gas outlet of the methanol synthesis column (2); a methanol synthesis regulating column (4), a gas outlet of the methanol synthesis regulating column (4) being connected to a gas inlet of the methanol separation device (3); a first regulating valve (5), connected between an output end of the main compressor (1) and a gas inlet of the methanol synthesis column (2); a second regulating valve (6), connected between the output end of the main compressor (1) and a gas inlet of the methanol synthesis regulating column (4); a recycle compressor (9), the methanol separation device (3) comprising a methanol outlet for outputting methanol and a recycle outlet connected to an input end of the recycle compressor (9), an output end of the recycle compressor (9) being connected to an input end of the first regulating valve (5) and an input end of the second regulating valve (6); a first water vapor separator (16), a water inlet of the first water vapor separator (16) being connected to a boiler feed water pipeline, a steam outlet of the first water vapor separator (16) being connected to a steam pipeline, the methanol synthesis column (2) being connected to a bottom inlet of the first water vapor separator (16), a bottom outlet of the first water vapor separator (16) being connected to the methanol synthesis column (2); a second water vapor separator (17), a water inlet of the second water vapor separator (17) being connected to the boiler feed water pipeline, a steam outlet of the second water vapor separator (17) being connected to the steam pipeline, the methanol synthesis regulating column (4) being connected to a bottom inlet of the second water vapor separator (17), a bottom outlet of the second water vapor separator (17) being connected to the methanol synthesis regulating column (4); the flexible methanol synthesis system having 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, the first regulating valve (5) and the second regulating valve (6) are both in an open state.

8. The flexible methanol synthesis system of claim 7, wherein, The maximum inlet load of the methanol synthesis tower (2) is defined as n1, and the maximum inlet load of the methanol synthesis adjustment tower (4) is defined as n2, 10% n1≤n2≤60% n1.

9. The flexible methanol synthesis system of claim 7, wherein, Further comprising: a third regulating valve (7) connected between the gas outlet of the methanol synthesis tower (2) and the gas inlet of the methanol synthesis adjustment tower (4); a fourth regulating valve (8) connected between the gas outlet of the methanol synthesis tower (2) and the gas inlet of the methanol separation device (3), wherein when the flexible methanol synthesis system is in the first state, the third regulating valve (7) and the fourth regulating valve (8) are in an open state; when the flexible methanol synthesis system is in the second state, the third regulating valve (7) is in a closed state; when the flexible methanol synthesis system is in the third state, the third regulating valve (7) is in a closed state, and the fourth regulating valve (8) is in an open state.

10. The flexible methanol synthesis system according to any one of claims 7 to 9, characterized in that, Further comprising: a first gas-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-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); a second gas-gas heat exchanger (11), wherein the output end of the second regulating valve (6) is connected to the shell side inlet of the second gas-gas heat exchanger (11), the shell side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol synthesis adjustment tower (4), the gas outlet of the methanol synthesis adjustment tower (4) is connected to the tube side inlet of the second gas-gas heat exchanger (11), and the tube side outlet of the second gas-gas heat exchanger (11) is connected to the gas inlet of the methanol separation device (3).

11. The flexible methanol synthesis system of claim 10, wherein, Further comprising: 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-gas heat exchanger (10); a sixth regulating valve (13) connected between the gas outlet of the methanol synthesis adjustment tower (4) and the tube side inlet of the second gas-gas heat exchanger (11); a seventh regulating valve (14) connected between the tube side outlet of the second gas-gas heat exchanger (11) and the gas inlet of the methanol separation device (3); an eighth regulating valve (15), wherein the input end of the eighth regulating valve (15) is connected to the gas outlet of the methanol synthesis adjustment tower (4), and the output end of the eighth regulating valve (15) is connected to the shell side inlet of the first gas-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-gas heat exchanger (10).

12. The flexible methanol synthesis system of claim 7 or 8, wherein, The methanol synthesis regulation towers are multiple, two adjacent methanol synthesis regulation towers (4) are defined as a first regulation tower and a second regulation tower respectively, a gas outlet of the first regulation tower is connected with a gas inlet of the second regulation tower through a tenth regulation valve (20), and a gas outlet of the second regulation tower is connected with a gas inlet of the first regulation tower through an eleventh regulation valve (21).

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