A cryogenic separation apparatus and method for producing high purity carbon monoxide and methane

Abstract

The application relates to a deep cooling separation device and production method for producing high-purity carbon monoxide and methane, which comprises a nitrogen refrigeration cycle and multi-tower rectification for producing high-purity electronic-grade 5N carbon monoxide and methane, wherein the nitrogen refrigeration cycle provides cold energy for deep cooling separation of raw gas, and liquid nitrogen washing towers, argon removal towers, nitrogen removal towers, methane removal towers, high-purity methane tower reboilers and high-purity carbon monoxide towers are arranged to remove hydrogen, nitrogen, argon, methane, ethane and propane and other impurities in the raw gas, so as to produce high-purity electronic-grade 5N carbon monoxide and methane, increase the added value of the factory, and return the purified synthetic ammonia raw gas to the factory for utilization, so that the benefit of the factory is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-temperature deep cooling liquefaction separation, in particular to a deep cooling separation device and method for producing high-purity carbon monoxide and methane. BACKGROUND

[0002] In the PSA hydrogen extraction section of a coke oven gas synthetic ammonia device, PSA hydrogen extraction desorption gas is produced, which mainly contains hydrogen, methane, CO, CO2, nitrogen and the like. This gas is often used as fuel gas, which not only causes waste of resources, but also causes environmental pollution. Using purified PSA hydrogen extraction desorption gas to produce synthetic ammonia raw gas and co-produce high-purity electronic-grade 5N carbon monoxide and methane not only turns waste into treasure, but also brings very good economic benefits to the factory. With the progress of science and technology, the electronics and photovoltaic industries are developing rapidly, and high-purity electronic-grade 5N carbon monoxide and methane are increasingly widely used in semiconductor dry etching, plasma etching, chemical vapor deposition and other processes, and can be used to prepare semiconductor materials, microelectronic devices, optoelectronic devices and the like. At present, high-purity electronic-grade 5N carbon monoxide and methane have become one of the important raw materials for the electronics industry, so the market space for high-purity electronic-grade 5N carbon monoxide and methane is continuously expanding, driving the high-purity electronic-grade 5N carbon monoxide and methane industry to continuously progress in technology and continuously improve product purity; therefore, a device for producing high-purity electronic-grade 5N carbon monoxide and methane is needed to improve product separation purity. SUMMARY

[0003] The present application aims to solve the technical defects in the above background, and provides a deep cooling separation device and method for producing high-purity carbon monoxide and methane.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0005] The device provided by the present invention includes a main heat exchanger, a liquid nitrogen washing tower, a low-temperature separator, a deargon tower, a deargon tower reboiler, a deargon tower condenser, a deargon tower reflux tank, a denitrogenation tower, a denitrogenation tower condenser, a denitrogenation tower reflux tank, a demethanizer, a main condenser evaporator, a demethanizer reflux tank, a demethanizer reboiler, a high-purity methane tower, a high-purity methane tower reboiler, a high-purity methane tower condenser, a high-purity carbon monoxide tower, a high-purity carbon monoxide tower reboiler, a high-purity carbon monoxide tower condenser, and a nitrogen compressor system; the main heat exchanger is provided with a high-pressure nitrogen I channel, a low-pressure nitrogen I channel, a raw gas channel, a low-low-pressure nitrogen channel, a carbon monoxide I channel, a hydrogen-rich gas channel, a nitrogen-rich gas I channel, a high-purity electronic-grade CO channel, a high-purity electronic-grade methane channel, a natural gas channel, a high-pressure nitrogen II channel, a high-pressure liquid nitrogen I channel, and a hydrogen-depleted liquid channel. The de-argon tower condenser is provided with a low-pressure nitrogen II channel and an argon-poor gas channel. The de-nitrogen tower condenser is provided with a low-pressure nitrogen III channel, a carbon monoxide II channel and a nitrogen-rich gas II channel.

[0006] Along the inlet direction of the raw gas, the raw gas channel inlet is connected to the external raw gas pipeline, and the raw gas channel outlet is connected to the feed port at the bottom of the liquid nitrogen scrubber. The top outlet of the liquid nitrogen scrubber is connected to the hydrogen-rich gas channel inlet, and the hydrogen-rich gas channel is connected to the external synthetic ammonia raw gas pipeline. The liquid phase outlet at the bottom of the liquid nitrogen scrubber is connected to the feed port of the low-temperature separator.

[0007] The gas phase outlet at the top of the low-temperature separator is connected to the nitrogen-rich gas I channel inlet pipeline, the liquid phase outlet at the bottom of the low-temperature separator is connected to the hydrogen-poor liquid channel inlet, the hydrogen liquid channel outlet is connected to the middle feed port of the demethanizer, the upper gas phase outlet at the middle of the demethanizer is connected to the feed port of the high-purity methane tower, the liquid phase outlet at the bottom of the high-purity methane tower is connected to the high-purity electronic-grade methane channel inlet, and the high-purity electronic-grade methane channel outlet is connected to the external high-purity electronic-grade methane pipeline.

[0008] The gas phase outlet pipeline at the top of the high-purity methane tower is connected to the liquid phase pipeline at the bottom of the demethanizer tower, and then connected to the natural gas channel inlet pipeline. The natural gas channel outlet is connected to the external normal temperature natural gas pipeline.

[0009] The upper gas phase outlet of the demethanizer is connected with the inlet of the main condenser evaporator, the outlet of the main condenser evaporator is connected with the feed inlet of the demethanizer reflux tank, the bottom liquid phase outlet of the demethanizer reflux tank is connected with the top feed inlet of the demethanizer, the top gas phase outlet of the demethanizer reflux tank is connected with the middle feed inlet of the deargon column, the bottom liquid phase outlet pipeline of the deargon column is connected with the inlet pipeline of the nitrogen-rich gas I channel, the top gas phase outlet of the deargon column is connected with the inlet of the argon-lean gas channel, the outlet of the argon-lean gas channel is connected with the feed inlet of the deargon reflux tank, the bottom liquid phase outlet of the deargon reflux tank is connected with the top feed inlet of the deargon column, the top gas phase outlet of the deargon reflux tank is connected with the middle feed inlet of the denitrogen column, the top gas phase outlet of the denitrogen column is connected with the inlet of the nitrogen-rich gas II channel, the outlet pipeline of the nitrogen-rich gas II channel is connected with the feed inlet of the denitrogen reflux tank, the bottom liquid phase outlet of the denitrogen reflux tank is connected with the top feed inlet of the denitrogen column, the top gas phase outlet pipeline of the denitrogen reflux tank is divided into two parts, one part is connected with the middle feed inlet of the high-purity carbon monoxide column, and the other part is connected with the inlet pipeline of the nitrogen-rich gas I channel,

[0010] The bottom liquid phase outlet of the high-purity carbon monoxide column is connected with the inlet of the high-purity electronic-grade CO channel, the outlet of the high-purity electronic-grade CO channel is connected with the high-purity electronic-grade CO pipeline outside the world, the top gas phase outlet of the high-purity carbon monoxide column is connected with the inlet pipeline of the nitrogen-rich gas I channel, the bottom liquid phase outlet of the denitrogen column is connected with the inlet of the carbon monoxide II channel, the outlet of the carbon monoxide II channel is connected with the inlet of the carbon monoxide I channel, the outlet of the carbon monoxide I channel is connected with the carbon monoxide gas pipeline outside the world, the inlet of the carbon monoxide I channel is connected with the top gas phase outlet of the low-temperature separator, the bottom liquid phase outlet pipeline of the deargon column, the top gas phase outlet of the denitrogen reflux tank and the top gas phase outlet of the high-purity carbon monoxide column, and the carbon monoxide I channel is connected with the nitrogen-rich gas pipeline outside the world.

[0011] Along the direction of the high-pressure nitrogen gas inlet, the nitrogen compressor system outlet is connected with the high-pressure nitrogen gas I channel inlet, the high-pressure nitrogen gas I channel outlet is connected with the demethanizer reboiler and the high-purity methane column reboiler inlet, the demethanizer reboiler and the high-purity methane column reboiler outlet are both connected with the high-pressure nitrogen gas II channel inlet, the high-pressure nitrogen gas II channel outlet is respectively connected with the deargon column reboiler and the high-purity carbon monoxide column reboiler inlet, the deargon column reboiler and the high-purity carbon monoxide column reboiler outlet are connected with the high-pressure liquid nitrogen I channel inlet, the high-pressure liquid nitrogen I channel outlet is respectively connected with the liquid nitrogen washing column top inlet, the low-pressure nitrogen gas II channel inlet, the low-pressure nitrogen gas III channel inlet, the high-purity methane column condenser liquid nitrogen inlet and the high-purity carbon monoxide column condenser liquid nitrogen inlet, the low-pressure nitrogen gas II channel outlet, the low-pressure nitrogen gas III channel outlet and the high-purity methane column condenser nitrogen outlet are connected with the low-pressure nitrogen gas I channel inlet, the low-pressure nitrogen gas I channel outlet is connected with the nitrogen compressor system secondary inlet, the high-purity carbon monoxide column condenser nitrogen outlet is connected with the low-low-pressure nitrogen gas channel inlet, and the low-low-pressure nitrogen gas channel is connected with the nitrogen compressor system primary inlet.

[0012] Preferably, an adjusting valve a is arranged between the high-pressure nitrogen gas II channel outlet and the high-pressure liquid nitrogen I channel inlet, and the adjusting valve a is electrically connected with the control system.

[0013] Further, the low-pressure nitrogen gas I channel inlet is provided with a temperature monitor I, and a temperature adjusting valve b is arranged between the high-pressure liquid nitrogen I channel outlet pipeline and the low-pressure nitrogen gas I channel inlet pipeline to control the temperature of the low-pressure nitrogen gas I channel inlet.

[0014] The bottom of the deargon column is provided with a temperature monitor II, and a temperature adjusting valve c is arranged between the deargon column reboiler nitrogen pipeline inlet and outlet to adjust the temperature of the deargon column bottom.

[0015] The poor argon gas channel outlet is provided with a temperature monitor III, and a temperature adjusting valve d is arranged in the poor argon gas channel outlet to adjust the temperature of the poor argon gas out of the poor argon gas channel.

[0016] The rich nitrogen gas II channel outlet is provided with a temperature monitor IV, and a temperature adjusting valve e is arranged in the low-pressure nitrogen gas III channel inlet to adjust the temperature of the rich nitrogen gas out of the rich nitrogen gas II channel.

[0017] The bottom of the demethanizer is provided with a temperature monitor V, and a temperature adjusting valve f is arranged between the demethanizer reboiler nitrogen pipeline inlet and outlet to adjust the temperature of the demethanizer bottom.

[0018] The top of the high-purity methane column is provided with a temperature monitor VI, and a temperature adjusting valve g is arranged in the high-purity methane column condenser liquid nitrogen inlet to adjust the temperature of the top of the high-purity methane column.

[0019] The high-purity methane column bottom is provided with a temperature monitor VII, and a temperature adjusting valve h is arranged between the nitrogen gas pipeline inlet and outlet of the high-purity methane column reboiler for adjusting the temperature of the high-purity methane column bottom.

[0020] The high-purity carbon monoxide column top is provided with a temperature monitor VIII, and a temperature adjusting valve i is arranged at the liquid nitrogen inlet of the high-purity carbon monoxide column condenser for adjusting the temperature of the high-purity carbon monoxide column top.

[0021] The high-purity carbon monoxide column bottom is provided with a temperature monitor IX, and a temperature adjusting valve j is arranged between the nitrogen gas pipeline inlet and outlet of the high-purity carbon monoxide column reboiler for adjusting the temperature of the high-purity carbon monoxide column bottom.

[0022] The temperature monitor I, the temperature monitor II, the temperature monitor III, the temperature monitor IV, the temperature monitor V, the temperature monitor VI, the temperature monitor VII, the temperature monitor VIII, the temperature monitor IX, the temperature adjusting valve b, the temperature adjusting valve c, the temperature adjusting valve d, the temperature adjusting valve e, the temperature adjusting valve f, the temperature adjusting valve g, the temperature adjusting valve h, the temperature adjusting valve i, and the temperature adjusting valve j are respectively electrically connected with the control system.

[0023] Further, the liquid nitrogen washing column bottom is provided with a liquid level monitor I, and a liquid level adjusting valve k is arranged at the liquid nitrogen washing column bottom outlet pipeline for adjusting the liquid level of the liquid nitrogen washing column bottom.

[0024] The low-temperature separator bottom is provided with a liquid level monitor II, and a liquid level adjusting valve l is arranged at the low-temperature separator bottom outlet pipeline for adjusting the liquid level of the low-temperature separator bottom.

[0025] The de-aromatization column bottom is provided with a liquid level monitor III, and a liquid level adjusting valve m is arranged at the de-aromatization column bottom outlet pipeline for adjusting the liquid level of the de-aromatization column bottom.

[0026] The de-methanization column bottom is provided with a liquid level monitor IV, and a liquid level adjusting valve n is arranged at the de-methanization column bottom outlet pipeline for adjusting the liquid level of the de-methanization column bottom.

[0027] The main condensation evaporator bottom is provided with a liquid level monitor V, and a liquid level adjusting valve o is arranged at the main condensation evaporator bottom outlet pipeline for adjusting the liquid level of the main condensation evaporator bottom.

[0028] The high-purity methane column bottom is provided with a liquid level monitor VI, and a liquid level adjusting valve p is arranged at the high-purity methane column bottom outlet pipeline for adjusting the liquid level of the high-purity methane column bottom.

[0029] The high-purity carbon monoxide tower bottom is provided with a liquid level monitor VII, and the high-purity carbon monoxide tower bottom outlet pipeline is provided with a liquid level regulating valve q for regulating the high-purity carbon monoxide tower bottom liquid level.

[0030] The liquid level monitor I, the liquid level monitor II, the liquid level monitor III, the liquid level monitor IV, the monitor V, the liquid level monitor VI, the liquid level monitor VII, the liquid level regulating valve k, the liquid level regulating valve l, the liquid level regulating valve m, the liquid level regulating valve n, the liquid level regulating valve o, the liquid level regulating valve p, and the liquid level regulating valve q are respectively electrically connected with the control system.

[0031] Preferably, the deep cooling separation device for producing high-purity carbon monoxide and methane according to claim 1 is characterized in that the liquid nitrogen washing tower top is provided with a pressure monitor I, and the liquid nitrogen washing tower top outlet pipeline is provided with a pressure regulating valve r for regulating the liquid nitrogen washing tower top pressure.

[0032] The low-temperature separator top is provided with a pressure monitor II, and the low-temperature separator top outlet pipeline is provided with a pressure regulating valve s for regulating the low-temperature separator top pressure.

[0033] The demethanizer top is provided with a pressure monitor III, and the demethanizer reflux tank top outlet pipeline is provided with a pressure regulating valve t for regulating the demethanizer top pressure.

[0034] The denitrogenation tower top is provided with a pressure monitor IV, and the pressure regulating valve u is arranged between the denitrogenation tower reflux tank top outlet pipeline and the rich nitrogen gas I channel inlet pipeline for regulating the denitrogenation tower top pressure.

[0035] The high-purity methane tower top is provided with a pressure monitor V, and the high-purity methane tower top outlet pipeline is provided with a pressure regulating valve v for regulating the high-purity methane tower top pressure.

[0036] The high-purity carbon monoxide tower top is provided with a pressure monitor VI, and the high-purity carbon monoxide tower top outlet pipeline is provided with a pressure regulating valve w for regulating the high-purity carbon monoxide tower top pressure.

[0037] The nitrogen gas compressor system secondary inlet is provided with a pressure monitor VII, and the external low-pressure nitrogen gas supplement pipeline is provided with a pressure regulating valve x for regulating the nitrogen gas compressor system secondary inlet pressure.

[0038] The pressure monitor I, the pressure monitor II, the pressure monitor III, the pressure monitor IV, the pressure monitor V, the pressure monitor VI, the pressure monitor VII, the pressure regulating valve r, the pressure regulating valve s, the pressure regulating valve t, the pressure regulating valve u, the pressure regulating valve v, the pressure regulating valve w, and the pressure regulating valve x are respectively electrically connected with the control system.

[0039] Further, the liquid nitrogen washing tower top feed inlet pipeline is provided with a flow monitor I, and the liquid nitrogen washing tower top feed inlet pipeline is provided with a flow regulating valve y for regulating the flow of the liquid nitrogen into the liquid nitrogen washing tower.

[0040] The high-purity methane tower middle feed pipeline is provided with a flow monitor II, and the high-purity methane tower middle feed pipeline is provided with a flow regulating valve z for regulating the flow of the methane-rich gas into the high-purity methane tower.

[0041] The high-purity carbon monoxide tower middle feed pipeline is provided with a flow monitor III, and the high-purity carbon monoxide tower middle feed pipeline is provided with a flow regulating valve a1 for regulating the flow of the CO-rich gas into the high-purity carbon monoxide tower.

[0042] The flow monitor I, the flow monitor II, the flow monitor III, the flow regulating valve y, the flow regulating valve z and the flow regulating valve a1 are electrically connected with the control system respectively.

[0043] Further, the liquid nitrogen washing tower, the argon removal tower, the nitrogen removal tower, the nitrogen removal tower condenser, the nitrogen removal tower reflux tank, the methane removal tower, the high-purity methane tower and the high-purity carbon monoxide tower are packed towers or plate towers.

[0044] A method for producing high-purity electronic-grade 5N carbon monoxide and methane by cryogenic separation, which comprises the following steps:

[0045] S1, the purified raw material gas (containing hydrogen, nitrogen, carbon monoxide, methane, a small amount of ethane, a small amount of propane and a small amount of argon) after purification enters the raw material gas channel of the main heat exchanger through the external raw material gas pipeline, is cooled and partially condensed to about -180 DEG C by the refluxed low-temperature gas, and then enters the bottom of the liquid nitrogen washing tower. In the liquid nitrogen washing tower, the raw material gas is condensed and washed by the liquid nitrogen flowing from top to bottom, and the hydrogen-rich gas with a CO content of less than 10 ppm is obtained at the top of the liquid nitrogen washing tower. The hydrogen-rich gas is reheated to normal temperature by the normal flow of the hot stream (mainly high-pressure nitrogen gas and raw material gas) in the main heat exchanger, and then sent out through the boundary area; the hydrogen-lean liquid is obtained at the bottom of the liquid nitrogen washing tower.

[0046] S2, the hydrogen-lean liquid flows to about 0.55 MPa through the liquid level regulating valve k, enters the low-temperature separator, flashes a part of the dissolved hydrogen, and then enters the nitrogen-rich gas I channel inlet pipeline after throttling through the pressure regulating valve s; the liquid at the bottom of the low-temperature separator returns to the hydrogen-lean liquid channel of the main heat exchanger after the liquid level regulating valve l, is reheated to about -152 DEG C, and then is sent into the middle part of the methane removal tower for the second rectification.

[0047] S3, further rectification and demethanization through the demethanizer, the demethanizer bottom is provided with a demethanizer reboiler to provide the demethanizer with rising evaporation gas, and the CO, N2 and Ar in the bottom liquid are rectified to obtain methane liquid (also containing a small amount of ethane and propane, referred to as LNG), which is throttled to ~0.2 MPa by a liquid level regulating valve n and then sent to the natural gas channel of the main heat exchanger to be reheated to normal temperature by a hot stream and used as the output natural gas; the CO-rich gas obtained at the top of the demethanizer enters the main condenser-evaporator and is condensed to enter the demethanizer reflux tank, the liquid is refluxed to the top of the demethanizer, and the gas is sent to the middle part of the argon removal tower for the third rectification.

[0048] S4, further rectification and argon and oxygen removal through the argon removal tower, the argon-rich liquid obtained at the bottom of the argon removal tower is throttled by a liquid level regulating valve m and then introduced into the inlet pipeline of the nitrogen-rich gas I channel; the argon-lean gas obtained at the top of the argon removal tower is cooled and partially condensed in the argon-lean gas channel, enters the argon removal reflux tank for gas-liquid separation, the separated liquid is all refluxed to the argon removal tower, and the separated gas (with an Ar content ≤50 ppm) is sent to the middle part of the nitrogen removal tower for the fourth rectification. The bottom of the argon removal tower is provided with an argon removal tower reboiler to provide the argon removal tower with rising evaporation gas, and the top of the argon removal tower is provided with an argon removal tower condenser and an argon removal reflux tank to provide the argon removal tower with top reflux liquid.

[0049] S5, the gas phase separated from the argon removal reflux tank is further rectified and denitrified through the nitrogen removal tower, the nitrogen-rich gas (composed of CO, N2 and a small amount of H2) obtained at the top of the nitrogen removal tower is returned to the nitrogen-rich gas I channel of the main heat exchanger to be reheated to normal temperature by a hot stream and then discharged from the cold box as output nitrogen-rich gas at 0.2 MPa and 31°C; the CO liquid obtained at the bottom of the nitrogen removal tower is used as a cold source for cooling the gas at the top of the demethanizer, the CO liquid is heated to provide the nitrogen removal tower with rising evaporation gas, the CO liquid is throttled to 0.12 MPa by a liquid level regulating valve o and then introduced into the carbon monoxide II channel of the nitrogen removal tower condenser to provide a cold source, and then returned to the carbon monoxide I channel of the main heat exchanger to be reheated to normal temperature by a hot stream (mainly high-pressure nitrogen gas and purified raw material gas) and then discharged from the cold box. The top of the nitrogen removal tower is provided with a nitrogen removal tower condenser and a nitrogen removal reflux tank to provide the nitrogen removal tower with top reflux liquid.

[0050] S6, the process is also provided with a high-purity methane tower and a high-purity carbon monoxide tower for producing high-purity methane and high-purity CO with a purity ≥99.999%; the methane-rich gas from the middle part of the demethanizer (composed of CH4, N2, CO and Ar) is adjusted by a flow regulating valve z and then introduced into the middle part of the high-purity methane tower, the bottom of the high-purity methane tower is provided with a high-purity methane tower reboiler to provide the high-purity methane tower with rising evaporation gas, and the CO, N2 and Ar in the bottom liquid LNG are rectified to obtain high-purity methane with a purity ≥99.999% and high-purity CO with a purity ≥99.999%.

[0051] ≥ 99.999% high purity methane liquid, after being adjusted by liquid level regulating valve p, is sent into the high purity electronic grade methane channel of the main heat exchanger and is reheated to normal temperature by the hot stream (mainly high pressure nitrogen gas and raw material gas) as the export high purity electronic grade 5N methane; a high purity methane column condenser is arranged at the top of the high purity methane column, liquid nitrogen is used as the cold source of the high purity methane column condenser to provide condensing reflux liquid for the high purity methane column, through the above distillation, methane-rich gas containing N2, CO and Ar is obtained at the top of the high purity methane column, after being adjusted by pressure regulating valve v, it is also sent into the natural gas channel of the main heat exchanger and is reheated to normal temperature by the hot stream (mainly high pressure nitrogen gas and purified raw material gas) as the export natural gas. The nitrogen-rich gas (components are CO, N2 and a small amount of H2) obtained from the top of the denitrogenation column takes a part into the middle of the high purity carbon monoxide column through flow regulating valve a1 for further distillation, a high purity carbon monoxide column reboiler is arranged at the bottom of the high purity carbon monoxide column to provide rising evaporation gas for the high purity carbon monoxide column, and to distill N2 and H2 in the liquid CO at the bottom to obtain ≥ 99.999% high purity CO liquid, after being adjusted by liquid level regulating valve q, it is sent into the high purity electronic grade CO channel of the main heat exchanger and is reheated to normal temperature by the hot stream (mainly high pressure nitrogen gas and raw material gas) as the export high purity electronic grade 5N CO. A high purity carbon monoxide column condenser is arranged at the top of the high purity carbon monoxide column, liquid nitrogen is used as the cold source of the high purity carbon monoxide column condenser to provide condensing reflux liquid for the high purity carbon monoxide column, through the above distillation, nitrogen-rich gas containing H2 and CO is obtained at the top of the high purity carbon monoxide column, after being adjusted by pressure regulating valve w, it is also sent into the nitrogen-rich gas I channel of the main heat exchanger and is reheated to normal temperature by the hot stream (mainly high pressure nitrogen gas and purified raw material gas) as the export nitrogen-rich gas.

[0052] S7, the cryogenic separation of raw gas is provided with washing liquid and cold quantity by nitrogen compressor. The nitrogen is compressed to 2.8 MPa by nitrogen compressor system and cooled to about 40 DEG C, then enters the high-pressure nitrogen passage of the main heat exchanger, is cooled, condensed and supercooled to-180 DEG C by the backflow low-temperature gas, and is divided into four ways: the first way is throttled by flow regulating valve y, then is sent to the top of the liquid nitrogen washing tower, washes and condenses the CO component in the hydrogen-rich gas; the second way is throttled by temperature adjusting valve d, temperature adjusting valve e and temperature adjusting valve g, then enters the argon removal tower condenser, the nitrogen removal tower condenser and the high-purity methane tower condenser to provide cold quantity, and is vaporized, the low-pressure nitrogen gas is discharged from the top of each tower; the third way is throttled by temperature adjusting valve b, then is combined with the low-pressure nitrogen gas discharged from the top of each tower, the low-pressure nitrogen gas is returned to the low-pressure nitrogen I passage of the main heat exchanger, is reheated to normal temperature by the hot flow (mainly high-pressure nitrogen gas and raw gas), then is discharged from the cold box, and is returned to the second inlet of the nitrogen compressor system; the fourth way is throttled by temperature adjusting valve j, then enters the high-purity carbon monoxide tower condenser to provide cold quantity, is vaporized into low-low-pressure nitrogen gas, the low-low-pressure nitrogen gas is returned to the low-low-pressure nitrogen passage of the main heat exchanger, is reheated to normal temperature by the hot flow, then is discharged from the cold box, and is returned to the first inlet of the nitrogen compressor system, is compressed again and circulates.

[0053] Based on the above technical scheme, the embodiment of the present application can at least produce the following technical effects:

[0054] (1) The present application provides a device for simultaneously preparing high-purity electronic-grade 5N carbon monoxide and methane, which overcomes the shortcomings of difficult preparation of electronic-grade carbon monoxide and methane and high energy consumption; the liquid nitrogen washing tower is used to wash and remove impurities such as methane, ethane, propane and carbon monoxide in the raw gas to prepare the raw gas for synthetic ammonia, and the high-purity electronic-grade 5N carbon monoxide and methane are produced through the demethanizing tower, the argon removal tower, the high-purity carbon monoxide tower and the high-purity methane tower, which increases the efficiency of the plant and reduces the emission of tail gas.

[0055] (2) The device provided by the present application uses nitrogen circulation as the cold quantity for the cryogenic separation of raw gas, which has the advantages of simple process, strong adaptability, easy operation and relatively low power consumption. The process flow is short, the utilization rate of raw gas is high, it can adapt to different load conditions, the equipment investment is low, one cold box of the present process includes low-temperature liquid nitrogen washing equipment and cryogenic liquefaction separation equipment, which can simultaneously produce high-purity electronic-grade 5N carbon monoxide and methane, and also provides raw gas for synthetic ammonia by liquid nitrogen washing. In addition, the device also has the advantages of convenient maintenance, reliable work, safety and reliability, wide practicality and the like. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 It is the whole structure schematic view of the embodiment 1 of the present application;

[0057] Figure 2 It is the whole structure schematic view of the embodiment 2 of the present application;

[0058] Figure: 1 - main heat exchanger, 2 - liquid nitrogen washing column, 3 - cryogenic separator, 4 - argon removal column, 5 - argon removal column reboiler, 6 - argon removal column condenser, 7 - argon removal column reflux drum, 8 - nitrogen removal column, 9 - nitrogen removal column condenser, 10 - nitrogen removal column reflux drum, 11 - methane removal column, 12 - main condensation evaporator, 13 - methane removal column reflux drum, 14 - methane removal column reboiler, 15 - high purity methane column, 16 - high purity methane column reboiler, 17 - high purity methane column condenser, 18 - high purity carbon monoxide column, 19 - high purity carbon monoxide column reboiler, 20 - high purity carbon monoxide column condenser, 21 - nitrogen compressor system; 23 - regulating valve a; 24 - temperature regulating valve b; 25 - liquid level regulating valve I; 26 - liquid level regulating valve k; 27 - pressure regulating valve s; 28 - flow regulating valve y; 29 - pressure regulating valve r; 30 - liquid level regulating valve m; 31 - pressure regulating valve t; 32 - temperature regulating valve d; 33 - temperature regulating valve e; 34 - flow regulating valve a1; 35 - liquid level regulating valve o; 36 - pressure regulating valve w; 37 - temperature regulating valve g; 38 - temperature regulating valve i; 39 - temperature regulating valve j; 40 - liquid level regulating valve p; 41 - liquid level regulating valve n; 42 - temperature regulating valve f; 43 - temperature regulating valve h; 44 - flow regulating valve z; 45 - pressure regulating valve v; 46 - pressure regulating valve u; 47 - pressure regulating valve x; 48 - liquid level regulating valve q.

[0059] A1 - high pressure nitrogen I channel, A2 - low pressure nitrogen I channel, A3 - raw gas channel, A4 - low low pressure nitrogen channel, A5 - carbon monoxide I channel, A6 - hydrogen-rich gas channel, A7 - nitrogen-rich gas I channel, A8 - high purity electronic grade CO channel, A9 - high purity electronic grade methane channel, A10 - natural gas channel, A11 - high pressure nitrogen II channel, A12 - high pressure liquid nitrogen I channel, A13 - hydrogen-lean liquid channel, B1 - low pressure nitrogen II channel, B2 - argon-lean gas channel, C1 - low pressure nitrogen III channel, C2 - carbon monoxide II channel, C3 - nitrogen-rich gas II channel. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. The described embodiments are only some of the embodiments of the present application, not all the embodiments, and the present application will be described in further detail below in combination with the embodiments of the drawings.

[0061] Embodiment one: the application provides a kind of production high-purity carbon monoxide and methane cryogenic separation device, including main heat exchanger 1, liquid nitrogen washing tower 2, low temperature separator 3, deargon column 4, deargon column reboiler 5, deargon column condenser 6, deargon column reflux tank 7, deazotization tower 8, deazotization tower condenser 9, deazotization tower reflux tank 10, demethanizer 11, main condensing evaporator 12, deazotization tower reflux tank 13, demethanizer reboiler 14, high-purity methane column 15, high-purity methane column reboiler 16, high-purity methane column condenser 17, high-purity carbon monoxide column 18, high-purity carbon monoxide column reboiler 19, high-purity carbon monoxide column condenser 20, nitrogen compressor system 21.The main heat exchanger 1 is provided with high-pressure nitrogen I channel A1, low-pressure nitrogen I channel A2, raw material gas channel A3, low-low-pressure nitrogen channel A4, carbon monoxide I channel A5, hydrogen-rich gas channel A6, rich nitrogen I channel A7, high-purity electronic grade CO channel A8, high-purity electronic grade methane channel A9, natural gas channel A10, high-pressure nitrogen II channel A11, high-pressure liquid nitrogen I channel A12 and hydrogen-lean liquid channel A13.The deargon column condenser 6 is provided with low-pressure nitrogen II channel B1 and poor argon channel B2.The deazotization tower condenser 9 is provided with low-pressure nitrogen III channel C1, carbon monoxide II channel C2 and rich nitrogen II channel C3.

[0062] In the present embodiment, along the direction of the feed gas inlet, the feed gas passage A3 inlet is connected with the outside feed gas pipeline, the feed gas passage A3 outlet is connected with the bottom inlet of the liquid nitrogen washing tower 2. The top outlet of the liquid nitrogen washing tower 2 is connected with the hydrogen-rich gas passage A6 inlet, the hydrogen-rich gas passage A6 is connected with the outside synthetic ammonia feed gas pipeline, the bottom liquid phase outlet of the liquid nitrogen washing tower 2 is connected with the feed inlet of the low-temperature separator 3, the top gas phase outlet of the low-temperature separator 3 is connected with the nitrogen-rich gas I passage A7 inlet pipeline, the bottom liquid phase outlet of the low-temperature separator 3 is connected with the hydrogen-lean liquid passage A13 inlet, the hydrogen liquid passage A13 outlet is connected with the middle inlet 11-A of the demethanizer 11, the middle and upper gas phase outlet 11-B of the demethanizer 11 is connected with the feed inlet of the high-purity methane tower 15, the bottom liquid phase outlet of the high-purity methane tower 15 is connected with the high-purity electronic-grade methane passage A9 inlet, the high-purity electronic-grade methane passage A9 outlet is connected with the outside high-purity electronic-grade methane pipeline, the top gas phase outlet pipeline of the high-purity methane tower 15 is combined with the bottom liquid phase pipeline of the demethanizer 11, and then connected with the natural gas passage A10 inlet pipeline, the natural gas passage A10 outlet is connected with the outside normal-temperature natural gas pipeline, the upper gas phase outlet of the demethanizer 11 is connected with the inlet of the main condenser evaporator 12, the outlet of the main condenser evaporator 12 is connected with the feed inlet of the demethane reflux tank 13, the bottom liquid phase outlet of the demethane reflux tank 13 is connected with the top feed inlet of the demethanizer 11, the top gas phase outlet of the demethane reflux tank 13 is connected with the middle feed inlet of the argon-removal tower 4, the bottom liquid phase outlet pipeline of the argon-removal tower 4 is connected with the nitrogen-rich gas I passage A7 inlet pipeline, the top gas phase outlet of the argon-removal tower 4 is connected with the argon-lean gas passage B2 inlet, the argon-lean gas passage B2 outlet is connected with the feed inlet of the argon-removal reflux tank 7, the bottom liquid phase outlet of the argon-removal reflux tank 7 is connected with the top feed inlet of the argon-removal tower 4, the top gas phase outlet of the argon-removal reflux tank 7 is connected with the middle feed inlet of the nitrogen-removal tower 8, the top gas phase outlet of the nitrogen-removal tower 8 is connected with the nitrogen-rich gas II passage C3 inlet, the outlet pipeline of the nitrogen-rich gas II passage C3 is connected with the feed inlet of the nitrogen-removal reflux tank 10, the bottom liquid phase outlet of the nitrogen-removal reflux tank 10 is connected with the top feed inlet of the nitrogen-removal tower 8, the top gas phase outlet pipeline of the nitrogen-removal reflux tank 10 is divided into two parts, one part is connected with the middle feed inlet of the high-purity carbon monoxide tower 18, and the other part is connected with the nitrogen-rich gas I passage A7 inlet pipeline, the bottom liquid phase outlet of the high-purity carbon monoxide tower 18 is connected with the high-purity electronic-grade CO passage A8 inlet, the high-purity electronic-grade CO passage A8 outlet is connected with the outside high-purity electronic-grade CO pipeline, the top gas phase outlet of the high-purity carbon monoxide tower 18 is connected with the nitrogen-rich gas I passage A7 inlet pipeline, the bottom liquid phase outlet 8-A of the nitrogen-removal tower 8 is connected with the carbon monoxide II passage C2 inlet, the carbon monoxide II passage C2 outlet is connected with the carbon monoxide I passage A5 inlet,The carbon monoxide I channel A5 outlet is connected with the external carbon monoxide pipeline, the carbon monoxide I channel A5 inlet is connected with the top gas phase outlet of the low-temperature separator 3, the bottom liquid phase outlet pipeline of the de-argon column 4, the top gas phase outlet of the de-argon column reflux tank 10 and the top gas phase outlet of the high-purity carbon monoxide column 18, and the carbon monoxide I channel A5 is connected with the external nitrogen-rich gas pipeline.

[0063] In the embodiment, along the gas inlet direction of the high-pressure nitrogen gas, the nitrogen gas compressor system 21 outlet is connected with the high-pressure nitrogen gas I channel A1 inlet, the high-pressure nitrogen gas I channel A1 outlet is connected with the de-methane column reboiler 14 and the high-purity methane column reboiler 16 inlet, the de-methane column reboiler 14 and the high-purity methane column reboiler 16 outlet are both connected with the high-pressure nitrogen gas II channel A11 inlet, the high-pressure nitrogen gas II channel A11 outlet is respectively connected with the de-argon column reboiler 5 and the high-purity carbon monoxide column reboiler 19 inlet, the de-argon column reboiler 5 and the high-purity carbon monoxide column reboiler 19 outlet are connected with the high-pressure liquid nitrogen I channel A12 inlet, the high-pressure liquid nitrogen I channel A12 outlet is respectively connected with the top feed inlet of the liquid nitrogen washing column 2, the low-pressure nitrogen gas II channel B1 inlet, the low-pressure nitrogen gas III channel C1 inlet, the high-purity methane column condenser 17 liquid nitrogen inlet and the high-purity carbon monoxide column condenser 20 liquid nitrogen inlet, the low-pressure nitrogen gas II channel B1 outlet, the low-pressure nitrogen gas III channel C1 outlet and the high-purity methane column condenser 17 nitrogen gas outlet are connected with the low-pressure nitrogen gas I channel A2 inlet, the low-pressure nitrogen gas I channel A2 outlet is connected with the secondary inlet of the nitrogen gas compressor system 21, the high-purity carbon monoxide column condenser 20 nitrogen gas outlet is connected with the low-low-pressure nitrogen gas channel A4 inlet, and the low-low-pressure nitrogen gas channel A4 is connected with the primary inlet of the nitrogen gas compressor system 21.

[0064] In the embodiment, the regulating valve a23 is electrically connected with the control system between the outlet of the high-pressure nitrogen II channel A11 and the inlet of the high-pressure liquid nitrogen I channel A12. Further, the temperature monitor I is arranged at the inlet of the low-pressure nitrogen I channel A2. The temperature regulating valve b24 is arranged between the outlet pipeline of the high-pressure liquid nitrogen I channel A12 and the inlet pipeline of the low-pressure nitrogen I channel A2 to control the temperature of the inlet of the low-pressure nitrogen I channel A2. The temperature monitor II is arranged at the bottom of the de-argon column 4. The temperature regulating valve c is arranged between the nitrogen pipeline inlet and outlet of the de-argon column reboiler 5 to adjust the temperature of the bottom of the de-argon column 4. The temperature monitor III is arranged at the outlet of the poor argon channel B2. The temperature regulating valve d32 is arranged at the outlet of the poor argon channel B2 to adjust the temperature of the poor argon outlet of the poor argon channel B2. The temperature monitor IV is arranged at the outlet of the rich nitrogen II channel C3. The temperature regulating valve e33 is arranged at the inlet of the low-pressure nitrogen III channel C1 to adjust the temperature of the rich nitrogen outlet of the rich nitrogen II channel C3. The temperature monitor V is arranged at the bottom of the de-methane column 11. The temperature regulating valve f42 is arranged between the nitrogen pipeline inlet and outlet of the de-methane column reboiler 14 to adjust the temperature of the bottom of the de-methane column 11. The temperature monitor VI is arranged at the top of the high-purity methane column 15. The temperature regulating valve g37 is arranged at the liquid nitrogen inlet of the high-purity methane column condenser 17 to adjust the temperature of the top of the high-purity methane column 15. The temperature monitor VII is arranged at the bottom of the high-purity methane column 15. The temperature regulating valve h43 is arranged between the nitrogen pipeline inlet and outlet of the high-purity methane column reboiler 16 to adjust the temperature of the bottom of the high-purity methane column 15. The temperature monitor VIII is arranged at the top of the high-purity carbon monoxide column 18. The temperature regulating valve i38 is arranged at the liquid nitrogen inlet of the high-purity carbon monoxide column condenser 20 to adjust the temperature of the top of the high-purity carbon monoxide column 18. The temperature monitor IX is arranged at the bottom of the high-purity carbon monoxide column 18. The temperature regulating valve j39 is arranged between the nitrogen pipeline inlet and outlet of the high-purity carbon monoxide column reboiler 19 to adjust the temperature of the bottom of the high-purity carbon monoxide column 18. The temperature monitor I, the temperature monitor II, the temperature monitor III, the temperature monitor IV, the temperature monitor V, the temperature monitor VI, the temperature monitor VII, the temperature monitor VIII, the temperature monitor IX, the temperature regulating valve b24, the temperature regulating valve c, the temperature regulating valve d32, the temperature regulating valve e33, the temperature regulating valve f42, the temperature regulating valve g37, the temperature regulating valve h43, the temperature regulating valve i38, and the temperature regulating valve j39 are electrically connected with the control system, respectively.

[0065] In the embodiment, the liquid nitrogen washing tower 2 is provided with a liquid level monitor I at the bottom, the liquid nitrogen washing tower 2 is provided with a liquid level adjusting valve k26 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the liquid nitrogen washing tower 2; the low-temperature separator 3 is provided with a liquid level monitor II at the bottom, the low-temperature separator 3 is provided with a liquid level adjusting valve l25 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the low-temperature separator 3; the de-aromatization tower 4 is provided with a liquid level monitor III at the bottom, the de-aromatization tower 4 is provided with a liquid level adjusting valve m30 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the de-aromatization tower 4; the de-methanization tower 11 is provided with a liquid level monitor IV at the bottom, the de-methanization tower 11 is provided with a liquid level adjusting valve n41 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the de-methanization tower 11; the main condensation evaporator 12 is provided with a liquid level monitor V at the bottom, the main condensation evaporator 12 is provided with a liquid level adjusting valve o35 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the main condensation evaporator 12; the high-purity methane tower 15 is provided with a liquid level monitor VI at the bottom, the high-purity methane tower 15 is provided with a liquid level adjusting valve p40 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the high-purity methane tower 15; the high-purity carbon monoxide tower 18 is provided with a liquid level monitor VII at the bottom, the high-purity carbon monoxide tower 18 is provided with a liquid level adjusting valve q48 at the bottom outlet pipeline, which is used to adjust the liquid level at the bottom of the high-purity carbon monoxide tower 18; the liquid level monitor I, the liquid level monitor II, the liquid level monitor III, the liquid level monitor IV, the monitor V, the liquid level monitor VI, the liquid level monitor VII, the liquid level adjusting valve k26, the liquid level adjusting valve l25, the liquid level adjusting valve m30, the liquid level adjusting valve n41, the liquid level adjusting valve o35, the liquid level adjusting valve p40, the liquid level adjusting valve q48 are electrically connected with the control system respectively.

[0066] In the embodiment, the liquid nitrogen washing tower 2 top is provided with pressure monitor I, the liquid nitrogen washing tower 2 top outlet pipeline is provided with pressure regulating valve r29, for adjusting the liquid nitrogen washing tower 2 top pressure;The low temperature separator 3 top is provided with pressure monitor II, the low temperature separator 3 top outlet pipeline is provided with pressure regulating valve s27, for adjusting the low temperature separator 3 top pressure;The demethanizer 11 top is provided with pressure monitor III, the demethanizer reflux tank 13 top outlet pipeline is provided with pressure regulating valve t31, for adjusting the demethanizer 11 top pressure;The denitrogenator 8 top is provided with pressure monitor IV, the denitrogenator reflux tank 10 top outlet pipeline and the rich nitrogen gas I channel A7 inlet pipeline between the pressure regulating valve u46 is provided, for adjusting the denitrogenator 8 top pressure;The high purity methane tower 15 top is provided with pressure monitor V, the high purity methane tower 15 top outlet pipeline is provided with pressure regulating valve v45, for adjusting the high purity methane tower 15 top pressure;The high purity carbon monoxide tower 18 top is provided with pressure monitor VI, the high purity carbon monoxide tower 18 top outlet pipeline is provided with pressure regulating valve w36, for adjusting the high purity carbon monoxide tower 18 top pressure;The nitrogen compressor system 21 secondary inlet is provided with pressure monitor VII, the external low pressure nitrogen supplement pipeline is provided with pressure regulating valve x47, for adjusting the nitrogen compressor system 21 secondary inlet pressure;The pressure monitor I, pressure monitor II, pressure monitor III, pressure monitor IV, pressure monitor V, pressure monitor VI, pressure monitor VII, pressure regulating valve r29, pressure regulating valve s27, pressure regulating valve t31, pressure regulating valve u46, pressure regulating valve v45, pressure regulating valve w36, pressure regulating valve x47 are electrically connected with control system respectively.

[0067] In the embodiment, the liquid nitrogen washing tower 2 top inlet pipeline is provided with flow monitor I, the liquid nitrogen washing tower 2 top inlet pipeline is provided with flow regulating valve y28, for adjusting the liquid nitrogen into the flow of liquid nitrogen washing tower 2;The high purity methane tower 15 middle inlet pipeline is provided with flow monitor II, the high purity methane tower 15 middle inlet pipeline is provided with flow regulating valve z44, for adjusting the rich methane gas into the flow of high purity methane tower 15;The high purity carbon monoxide tower 18 middle inlet pipeline is provided with flow monitor III, the high purity carbon monoxide tower 18 middle inlet pipeline is provided with flow regulating valve a134, for adjusting the rich CO gas into the flow of high purity carbon monoxide tower 18;The flow monitor I, flow monitor II, flow monitor III, flow regulating valve y28, flow regulating valve z44, flow regulating valve a134 are electrically connected with control system respectively.

[0068] In the embodiment, the liquid nitrogen washing tower 2, the argon removal tower 4, the nitrogen removal tower 8, the methane removal tower 11, and the high-purity methane tower 15 are packed towers or plate towers.

[0069] In order to facilitate understanding of the device of the embodiment, the device provided by the embodiment is used to produce high-purity electronic-grade 5N carbon monoxide and methane, and specifically includes the following steps.

[0070] S1, the purified raw material gas (containing hydrogen, nitrogen, carbon monoxide, methane, a small amount of ethane, a small amount of propane, and a small amount of argon) is introduced into the raw material gas passage A3 of the main heat exchanger 1 through the external raw material gas pipeline, is cooled and partially condensed to about -180 DEG C by the backflow low-temperature gas, and then is introduced into the bottom of the liquid nitrogen washing tower 2. In the liquid nitrogen washing tower 2, the raw material gas is condensed and washed by the liquid nitrogen flowing from top to bottom, and the hydrogen-rich gas with a CO content of less than 10 ppm is obtained at the top of the liquid nitrogen washing tower 2. The hydrogen-rich gas is reheated to normal temperature by the hot stream (mainly high-pressure nitrogen gas and raw material gas) flowing forward in the main heat exchanger 1, and then is sent out through the boundary area; the hydrogen-lean liquid is obtained at the bottom of the liquid nitrogen washing tower 2.

[0071] S2, the hydrogen-lean liquid is introduced into the low-temperature separator 3 after being flowed to about 0.55 MPa through the liquid level adjusting valve k26, a part of the dissolved hydrogen is flashed out, is throttled through the pressure adjusting valve s27, and is introduced into the nitrogen-rich gas I passage A7 inlet pipeline; the liquid at the bottom of the low-temperature separator 3 is returned to the hydrogen-lean liquid passage A13 of the main heat exchanger 1 after being flowed through the liquid level adjusting valve l25, is reheated to about -152 DEG C, and then is sent into the middle part of the methane removal tower 11 to perform the second rectification.

[0072] S3, the methane is removed through the further rectification of the methane removal tower 11, the methane removal tower reboiler 14 is arranged at the bottom of the methane removal tower 11, the rising evaporation gas is provided for the methane removal tower 11, the CO, N2 and Ar in the liquid at the bottom of the methane removal tower 11 are rectified, the methane liquid (also containing a small amount of ethane and propane, referred to as LNG) is obtained, is throttled to about 0.2 MPa through the liquid level adjusting valve n41, is reheated to normal temperature by the hot stream in the natural gas passage A10 of the main heat exchanger 1, and then is sent out as the output natural gas; the CO-rich gas obtained at the top of the methane removal tower 11 is introduced into the main condenser evaporator 12, is condensed, is introduced into the methane removal tower backflow tank 13, the liquid is backflowed to the top of the methane removal tower 11, and the gas is sent to the middle part of the argon removal tower 4 to perform the third rectification.

[0073] S4, the argon and oxygen are further rectified in the argon removal column 4, the argon-rich liquid at the bottom of the column is throttled by the liquid level regulating valve m30 and then enters the inlet pipeline of the argon-rich gas I passage A7, the argon-lean gas at the top of the column is cooled and partially condensed, enters the reflux tank 7 of the argon removal column and is subjected to gas-liquid separation, the separated liquid phase is totally refluxed to the argon removal column 4, and the separated gas phase (with an Ar content of ≤50 ppm) is sent to the middle part of the nitrogen removal column 8 and is subjected to fourth rectification. The bottom of the argon removal column 4 is provided with the argon removal column reboiler 5 for providing the rising evaporation gas for the argon removal column 4, and the top of the argon removal column 4 is provided with the argon removal column condenser 6 and the argon removal column reflux tank 7 for providing the column top reflux liquid for the argon removal column 4.

[0074] S5, the gas phase separated from the argon removal column reflux tank 7 is subjected to further rectification and denitrification in the nitrogen removal column 8, the argon-lean gas (with components of CO, N2 and a small amount of H2) at the top of the nitrogen removal column 8 is returned to the argon-rich gas I passage A7 of the main heat exchanger 1, is reheated to normal temperature by the hot stream and is discharged from the cold box as the exported argon-rich gas at a condition of 0.2 MPa and 31℃, the CO liquid at the bottom of the nitrogen removal column 8 provides a cold source for the gas cooling at the top of the demethanizer 11, is heated and then provides the rising evaporation gas for the nitrogen removal column 8, is throttled to 0.12 MPa by the liquid level regulating valve o35, enters the carbon monoxide II passage C2 of the nitrogen removal column condenser 9 and provides a cold source, and is then returned to the carbon monoxide I passage A5 of the main heat exchanger 1, is reheated to normal temperature by the hot stream (mainly high-pressure nitrogen gas and the purified raw material gas) and is discharged from the cold box. The top of the nitrogen removal column 8 is provided with the nitrogen removal column condenser 9 and the nitrogen removal column reflux tank 10 for providing the column top reflux liquid for the nitrogen removal column 8.

[0075] S6, the process is also provided with a high-purity methane column 15 and a high-purity carbon monoxide column 18 for producing high-purity methane and high-purity CO with a purity of ≥ 99.999%. The methane-rich gas (whose components are CH4, N2, CO, and Ar) from the middle of the demethanizer 11 is adjusted by a flow regulating valve z44 and then enters the middle of the high-purity methane column 15, which is provided with a high-purity methane column reboiler 16 at the bottom to provide the high-purity methane column 15 with rising vaporization gas, and the CO, N2, and Ar in the liquid LNG at the bottom are rectified to obtain high-purity methane liquid with a purity of ≥ 99.999%, which is sent to the high-purity electronic-grade methane passage A9 of the main heat exchanger (1) after being adjusted by a liquid level regulating valve p40, is reheated to normal temperature by a hot stream (mainly high-pressure nitrogen gas and raw material gas), and is exported as high-purity electronic-grade 5N methane; the high-purity methane column 15 is provided with a high-purity methane column condenser 17 at the top, liquid nitrogen is used as the cold source of the high-purity methane column condenser 17 to provide the high-purity methane column 15 with condensed reflux liquid, and through the above rectification, the methane-rich gas containing N2, CO, and Ar is obtained at the top of the high-purity methane column 15, is also sent to the natural gas passage A10 of the main heat exchanger 1 after being adjusted by a pressure regulating valve v45, is reheated to normal temperature by a hot stream (mainly high-pressure nitrogen gas and purified raw material gas), and is exported as natural gas. The nitrogen-rich gas (whose components are CO, N2, and a small amount of H2) obtained from the top of the denitrogenation column 8 is taken to the middle of the high-purity carbon monoxide column 18 by a flow regulating valve a134 to be further rectified, the high-purity carbon monoxide column 18 is provided with a high-purity carbon monoxide column reboiler 19 at the bottom to provide the high-purity carbon monoxide column 18 with rising vaporization gas, and the N2 and H2 in the liquid CO at the bottom are rectified to obtain high-purity CO liquid with a purity of ≥ 99.999%, which is sent to the high-purity electronic-grade CO passage A8 of the main heat exchanger 1 after being adjusted by a liquid level regulating valve q(48), is reheated to normal temperature by a hot stream (mainly high-pressure nitrogen gas and raw material gas), and is exported as high-purity electronic-grade 5N CO. The high-purity carbon monoxide column 18 is provided with a high-purity carbon monoxide column condenser 20 at the top, liquid nitrogen is used as the cold source of the high-purity carbon monoxide column condenser 20 to provide the high-purity carbon monoxide column 18 with condensed reflux liquid, and through the above rectification, the nitrogen-rich gas containing H2 and CO is obtained at the top of the high-purity carbon monoxide column 18, is also sent to the nitrogen-rich gas I passage A7 of the main heat exchanger 1 after being adjusted by a pressure regulating valve w36, is reheated to normal temperature by a hot stream (mainly high-pressure nitrogen gas and purified raw material gas), and is exported as nitrogen-rich gas.

[0076] S7, the cryogenic separation of the raw gas is provided with washing liquid and cold energy by the nitrogen compressor. The nitrogen is compressed to 2.8 MPa by the nitrogen compressor system 21 and cooled to about 40℃, then enters the high-pressure nitrogen channel of the main heat exchanger 1, is cooled, condensed and supercooled to-180℃ by the backflow low-temperature gas, and is divided into four paths: the first path is throttled by the flow regulating valve y28 and sent to the top of the liquid nitrogen washing tower 2, washes and condenses the CO component in the hydrogen-rich gas; the second path is throttled by the temperature regulating valve d32, the temperature regulating valve e33 and the temperature regulating valve g37, respectively enters the argon removal tower condenser 6, the nitrogen removal tower condenser 9 and the high-purity methane tower condenser 17 to provide cold energy, and is vaporized, the low-pressure nitrogen gas out of the top of each tower condenser; the third path liquid nitrogen is throttled by the temperature regulating valve b24 and merged with the low-pressure nitrogen gas out of each tower condenser, the low-pressure nitrogen gas returns to the low-pressure nitrogen I channel A2 of the main heat exchanger 1, is reheated to normal temperature by the hot stream (mainly high-pressure nitrogen gas and raw gas) and then out of the cold box, returns to the two-stage inlet of the nitrogen compressor system 21; the fourth path liquid nitrogen is throttled by the temperature regulating valve j39, enters the high-purity carbon monoxide tower condenser 20 to provide cold energy, and is vaporized into low-low-pressure nitrogen gas, the low-low-pressure nitrogen gas returns to the low-low-pressure nitrogen channel A4 of the main heat exchanger 1, is reheated to normal temperature by the hot stream and then out of the cold box, returns to the one-stage inlet of the nitrogen compressor system 21, is compressed again and circulates.

[0077] The present embodiment can be implemented according to the purified raw gas parameters in the following table, and the parameters and components of the obtained normal temperature natural gas, CO gas, hydrogen-rich gas, nitrogen-rich gas, high-purity electronic grade CO and high-purity electronic grade methane are shown in the following table 1:

[0078] Table 1 parameters and components of example 1

[0079]

[0080] The hydrogen-rich gas is used as the raw material gas for ammonia synthesis, and the sum of the impurity contents such as methane, CO and CO2 in the components is less than 10ppm; in addition, the high-purity electronic grade methane meets the standard GB / T33102-2016 and the purity (mol%) is ≥99.999%; the high-purity electronic grade CO has a purity ≥99.999% and O2+Ar:≤1PPm, N2:<4PPm, H2:<0.5PPm, CO2:<0.5PPm, CH4:<0.35PPm, H2O:<0.6PPm, Ni:<0.07wt PPb, Fe(CO)5:<0.1wt PPb, particles (>0.1um) <5PCS / L.

[0081] Example two: when there is no argon content in the raw gas components, as shown in the following table 2, the difference between this embodiment and example one is that the argon removal tower 4, the argon removal tower reboiler 5, the argon removal tower condenser 6 and the argon removal tower reflux tank 7 are cancelled, and the gas phase outlet at the top of the demethanization tower reflux tank (13) is connected with the middle inlet of the nitrogen removal tower 8. Figure 2 ​

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. It can be understood that the present application is described through some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present application. In addition, under the guidance of the present application, these features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. A cryogenic separation device for producing high-purity carbon monoxide and methane, characterized in that: The device comprises a main heat exchanger (1), a liquid nitrogen washing tower (2), a low-temperature separator (3), a deargon tower (4), a deargon tower reboiler (5), a deargon tower condenser (6), a deargon tower reflux tank (7), a denitrification tower (8), a denitrification tower condenser (9), a denitrification tower reflux tank (10), a demethanizer (11), a main condenser evaporator (12), a demethanizer reflux tank (13), a demethanizer reboiler (14), a high-purity methane tower (15), a high-purity methane tower reboiler (16), a high-purity methane tower condenser (17), a high-purity carbon monoxide tower (18), a high-purity carbon monoxide tower reboiler (19), a high-purity carbon monoxide tower condenser (20), and a nitrogen compressor system (21); a high-pressure nitrogen is provided in the main heat exchanger (1). Gas I channel (A1), low-pressure nitrogen I channel (A2), raw gas channel (A3), low-pressure nitrogen channel (A4), carbon monoxide I channel (A5), hydrogen-rich gas channel (A6), nitrogen-rich gas I channel (A7), high-purity electronic-grade CO channel (A8), high-purity electronic-grade methane channel (A9), natural gas channel (A10), high-pressure nitrogen II channel (A11), high-pressure liquid nitrogen I channel (A12) and hydrogen-poor liquid channel (A13); the deargon tower condenser (6) is provided with a low-pressure nitrogen II channel (B1) and an argon-poor gas channel (B2); the denitrification tower condenser (9) is provided with a low-pressure nitrogen III channel (C1), carbon monoxide II channel (C2) and nitrogen-rich gas II channel (C3); The inlet of the raw gas channel (A3) is connected to an external raw gas pipeline, and the outlet of the raw gas channel (A3) is connected to the bottom feed port of the liquid nitrogen washing tower (2); the top outlet of the liquid nitrogen washing tower (2) is connected to the inlet of the hydrogen-rich gas channel (A6), and the hydrogen-rich gas channel (A6) is connected to an external synthetic ammonia raw gas pipeline; the liquid phase outlet at the bottom of the liquid nitrogen washing tower (2) is connected to the feed port of the low-temperature separator (3); The gas phase outlet at the top of the low-temperature separator (3) is connected to the inlet pipeline of the nitrogen-rich gas I channel (A7), the liquid phase outlet at the bottom of the low-temperature separator (3) is connected to the inlet of the hydrogen-poor liquid channel (A13), and the outlet of the hydrogen liquid channel (A13) is connected to the middle feed port (11-A) of the demethanizer (11); The gas phase outlet (11-B) in the upper middle portion of the demethanizer (11) is connected to the feed port of the high-purity methane tower (15), the liquid phase outlet at the bottom of the high-purity methane tower (15) is connected to the inlet of the high-purity electronic-grade methane channel (A9), and the outlet of the high-purity electronic-grade methane channel (A9) is connected to an external high-purity electronic-grade methane pipeline; The gas phase outlet pipeline at the top of the high-purity methane tower (15) is connected to the liquid phase pipeline at the bottom of the demethanizer (11) and then connected to the inlet pipeline of the natural gas channel (A10). The outlet of the natural gas channel (A10) is connected to the external normal temperature natural gas pipeline; The upper gas phase outlet of the demethanizer (11) is connected to the inlet of the main condenser evaporator (12), the outlet of the main condenser evaporator (12) is connected to the feed port of the demethanizer reflux tank (13), and the bottom liquid phase outlet of the demethanizer reflux tank (13) is connected to the top feed port of the demethanizer (11); The gas phase outlet at the top of the demethanizer reflux tank (13) is connected to the middle feed port of the deargon tower (4), the liquid phase outlet pipeline at the bottom of the deargon tower (4) is connected to the inlet pipeline of the nitrogen-rich gas I channel (A7), the gas phase outlet at the top of the deargon tower (4) is connected to the inlet of the lean argon gas channel (B2), the outlet of the lean argon gas channel (B2) is connected to the feed port of the deargon tower reflux tank (7), the liquid phase outlet at the bottom of the deargon tower reflux tank (7) is connected to the top feed port of the deargon tower (4), and the gas phase outlet at the top of the deargon tower reflux tank (7) is connected to the middle feed port of the denitrification tower (8); The gas phase outlet at the top of the denitrification tower (8) is connected to the inlet of the nitrogen-rich gas II channel (C3), the outlet pipeline of the nitrogen-rich gas II channel (C3) is connected to the feed port of the denitrification tower reflux tank (10), the liquid phase outlet at the bottom of the denitrification tower reflux tank (10) is connected to the feed port at the top of the denitrification tower (8), and the gas phase outlet pipeline at the top of the denitrification tower reflux tank (10) is divided into two parts, one part is connected to the middle feed port of the high-purity carbon monoxide tower (18), and the other part is connected to the inlet pipeline of the nitrogen-rich gas I channel (A7); The liquid phase outlet at the bottom of the high-purity carbon monoxide tower (18) is connected to the inlet of the high-purity electronic grade CO channel (A8), the outlet of the high-purity electronic grade CO channel (A8) is connected to the external high-purity electronic grade CO pipeline, and the gas phase outlet at the top of the high-purity carbon monoxide tower (18) is connected to the inlet pipeline of the nitrogen-rich gas I channel (A7); The liquid phase outlet (8-A) at the bottom of the denitrification tower (8) is connected to the inlet of the carbon monoxide II channel (C2), the outlet of the carbon monoxide II channel (C2) is connected to the inlet of the carbon monoxide I channel (A5), and the outlet of the carbon monoxide I channel (A5) is connected to the external carbon monoxide gas pipeline; The inlet of the carbon monoxide I channel (A5) is connected to the gas phase outlet at the top of the low-temperature separator (3), the liquid phase outlet pipeline at the bottom of the deargonization tower (4), the gas phase outlet at the top of the denitrification tower reflux tank (10), and the gas phase outlet at the top of the high-purity carbon monoxide tower (18), and the carbon monoxide I channel (A5) is connected to the external nitrogen-rich gas pipeline; The outlet of the nitrogen compressor system (21) is connected to the inlet of the high-pressure nitrogen I channel (A1), and the outlet of the high-pressure nitrogen I channel (A1) is connected to the inlets of the demethanizer reboiler (14) and the high-purity methane tower reboiler (16); The outlets of the demethanizer reboiler (14) and the high-purity methane tower reboiler (16) are both connected to the inlet of the high-pressure nitrogen II channel (A11), and the outlet of the high-pressure nitrogen II channel (A11) is respectively connected to the inlet of the deargon tower reboiler (5) and the high-purity carbon monoxide tower reboiler (19), and the outlets of the deargon tower reboiler (5) and the high-purity carbon monoxide tower reboiler (19) are connected to the inlet of the high-pressure liquid nitrogen I channel (A12), and the outlet of the high-pressure liquid nitrogen I channel (A12) is respectively connected to the top feed port of the liquid nitrogen washing tower (2), the inlet of the low-pressure nitrogen II channel (B1), the inlet of the low-pressure nitrogen III channel (C1), The liquid nitrogen inlet of the high-purity methane tower condenser (17) is connected to the liquid nitrogen inlet of the high-purity carbon monoxide tower condenser (20); the outlet of the low-pressure nitrogen II channel (B1), the outlet of the low-pressure nitrogen III channel (C1) and the nitrogen outlet of the high-purity methane tower condenser (17) are connected to the inlet of the low-pressure nitrogen I channel (A2); the outlet of the low-pressure nitrogen I channel (A2) is connected to the secondary inlet of the nitrogen compressor system (21); the nitrogen outlet of the high-purity carbon monoxide tower condenser (20) is connected to the inlet of the low-low-pressure nitrogen channel (A4); and the low-low-pressure nitrogen channel (A4) is connected to the primary inlet of the nitrogen compressor system (21).

2. A cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 1, characterized in that: A regulating valve a (23) is provided between the outlet of the high-pressure nitrogen II channel (A11) and the inlet of the high-pressure liquid nitrogen I channel (A12) and is electrically connected to the control system; The inlet of the low-pressure nitrogen I channel (A2) is provided with a temperature monitor I, and the outlet pipeline of the high-pressure liquid nitrogen I channel (A12) and the inlet pipeline of the low-pressure nitrogen I channel (A2) are provided with a temperature regulating valve b (24) for controlling the inlet temperature of the low-pressure nitrogen I channel (A2); A temperature monitor II is provided at the bottom of the de-argon tower (4), and a temperature regulating valve c is provided between the inlet and outlet of the nitrogen pipeline of the de-argon tower reboiler (5) for regulating the temperature at the bottom of the de-argon tower (4); The outlet of the lean argon gas channel (B2) is provided with a temperature monitor III, and the outlet of the lean argon gas channel (B2) is provided with a temperature regulating valve d (32) for regulating the temperature of the lean argon gas exiting the lean argon gas channel (B2); The outlet of the nitrogen-rich gas II channel (C3) is provided with a temperature monitor IV, and the inlet of the low-pressure nitrogen gas III channel (C1) is provided with a temperature regulating valve e (33) for regulating the temperature of the nitrogen-rich gas exiting the nitrogen-rich gas II channel (C3); A temperature monitor V is provided at the bottom of the demethanizer (11), and a temperature regulating valve f (42) is provided between the inlet and outlet of the nitrogen pipeline of the demethanizer reboiler (14) for regulating the temperature at the bottom of the demethanizer (11); The top of the high-purity methane tower (15) is provided with a temperature monitor VI, and the liquid nitrogen inlet of the high-purity methane tower condenser (17) is provided with a temperature regulating valve g (37) for regulating the top temperature of the high-purity methane tower (15); A temperature monitor VII is provided at the bottom of the high-purity methane tower (15), and a temperature regulating valve h (43) is provided between the inlet and outlet of the nitrogen pipeline of the high-purity methane tower reboiler (16) for regulating the bottom temperature of the high-purity methane tower (15); A temperature monitor VIII is provided at the top of the high-purity carbon monoxide tower (18), and a temperature regulating valve i (38) is provided at the liquid nitrogen inlet of the high-purity carbon monoxide tower condenser (20) for regulating the temperature at the top of the high-purity carbon monoxide tower (18); A temperature monitor IX is provided at the bottom of the high-purity carbon monoxide tower (18); a temperature regulating valve j (39) is provided between the inlet and outlet of the nitrogen pipeline of the high-purity carbon monoxide tower reboiler (19) for regulating the bottom temperature of the high-purity carbon monoxide tower (18); The temperature monitor I, temperature monitor II, temperature monitor III, temperature monitor IV, temperature monitor V, temperature monitor VI, temperature monitor VII, temperature monitor VIII, temperature monitor IX, temperature regulating valve b (24), temperature regulating valve c, temperature regulating valve d (32), temperature regulating valve e (33), temperature regulating valve f (42), temperature regulating valve g (37), temperature regulating valve h (43), temperature regulating valve i (38), and temperature regulating valve j (39) are electrically connected to the control system, respectively.

3. A cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 2, characterized in that: A liquid level monitor I is provided at the bottom of the liquid nitrogen washing tower (2), and a liquid level regulating valve k (26) is provided at the outlet pipe at the bottom of the liquid nitrogen washing tower (2) for regulating the liquid level at the bottom of the liquid nitrogen washing tower (2); A liquid level monitor II is provided at the bottom of the low-temperature separator (3), and a liquid level regulating valve l (25) is provided at the outlet pipe at the bottom of the low-temperature separator (3) for regulating the liquid level at the bottom of the low-temperature separator (3); A liquid level monitor III is provided at the bottom of the deargonization tower (4), and a liquid level regulating valve m (30) is provided at the outlet pipe at the bottom of the deargonization tower (4) for regulating the liquid level at the bottom of the deargonization tower (4); A liquid level monitor IV is provided at the bottom of the demethanizer (11), and a liquid level regulating valve n (41) is provided at the outlet pipe at the bottom of the demethanizer (11) for regulating the liquid level at the bottom of the demethanizer (11); A liquid level monitor V is provided at the bottom of the main condenser evaporator (12), and a liquid level regulating valve o (35) is provided at the outlet pipe at the bottom of the main condenser evaporator (12) for regulating the liquid level at the bottom of the main condenser evaporator (12); A liquid level monitor VI is provided at the bottom of the high-purity methane tower (15), and a liquid level regulating valve p (40) is provided at the outlet pipe at the bottom of the high-purity methane tower (15) for regulating the liquid level at the bottom of the high-purity methane tower (15); A liquid level monitor VII is provided at the bottom of the high-purity carbon monoxide tower (18), and a liquid level regulating valve q (48) is provided at the outlet pipe at the bottom of the high-purity carbon monoxide tower (18) for regulating the liquid level at the bottom of the high-purity carbon monoxide tower (18); The liquid level monitor I, liquid level monitor II, liquid level monitor III, liquid level monitor IV, monitor V, liquid level monitor VI, liquid level monitor VII, liquid level regulating valve k (26), liquid level regulating valve l (25), liquid level regulating valve m (30), liquid level regulating valve n (41), liquid level regulating valve o (35), liquid level regulating valve p (40), and liquid level regulating valve q (48) are electrically connected to the control system, respectively.

4. A cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 3, characterized in that: A pressure monitor I is provided at the top of the liquid nitrogen washing tower (2), and a pressure regulating valve r (29) is provided at the outlet pipe at the top of the liquid nitrogen washing tower (2) for regulating the pressure at the top of the liquid nitrogen washing tower (2); The top of the low-temperature separator (3) is provided with a pressure monitor II, and the outlet pipe at the top of the low-temperature separator (3) is provided with a pressure regulating valve s (27) for regulating the pressure at the top of the low-temperature separator (3); A pressure monitor III is provided on the top of the demethanizer (11), and a pressure regulating valve t (31) is provided on the outlet pipe at the top of the demethanizer reflux tank (13) for regulating the pressure at the top of the demethanizer (11); A pressure monitor IV is provided on the top of the denitrification tower (8), and a pressure regulating valve u (46) is provided between the outlet pipeline on the top of the denitrification tower reflux tank (10) and the inlet pipeline of the nitrogen-rich gas I channel (A7) for regulating the pressure on the top of the denitrification tower (8); A pressure monitor V is provided at the top of the high-purity methane tower (15), and a pressure regulating valve v (45) is provided at the outlet pipe at the top of the high-purity methane tower (15) for regulating the pressure at the top of the high-purity methane tower (15); A pressure monitor VI is provided at the top of the high-purity carbon monoxide tower (18), and a pressure regulating valve w (36) is provided at the outlet pipe at the top of the high-purity carbon monoxide tower (18) for regulating the pressure at the top of the high-purity carbon monoxide tower (18); The secondary inlet of the nitrogen compressor system (21) is provided with a pressure monitor VII, and the external low-pressure nitrogen supply pipeline is provided with a pressure regulating valve x (47) for regulating the secondary inlet pressure of the nitrogen compressor system (21); The pressure monitor I, pressure monitor II, pressure monitor III, pressure monitor IV, pressure monitor V, pressure monitor VI, pressure monitor VII, pressure regulating valve r (29), pressure regulating valve s (27), pressure regulating valve t (31), pressure regulating valve u (46), pressure regulating valve v (45), pressure regulating valve w (36), and pressure regulating valve x (47) are electrically connected to the control system, respectively.

5. A cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 4, characterized in that: The top feed inlet pipeline of the liquid nitrogen washing tower (2) is provided with a flow monitor I, and the top feed inlet pipeline of the liquid nitrogen washing tower (2) is provided with a flow regulating valve y (28) for regulating the flow of liquid nitrogen entering the liquid nitrogen washing tower (2); The middle feed pipeline of the high-purity methane tower (15) is provided with a flow monitor II, and the middle feed pipeline of the high-purity methane tower (15) is provided with a flow regulating valve z (44) for regulating the flow of the methane-rich gas entering the high-purity methane tower (15); The middle feed pipeline of the high-purity carbon monoxide tower (18) is provided with a flow monitor III, and the middle feed pipeline of the high-purity carbon monoxide tower (18) is provided with a flow regulating valve a1 (34) for regulating the flow of CO-rich gas entering the high-purity carbon monoxide tower (18); The flow monitor I, flow monitor II, flow monitor III, flow regulating valve y (28), flow regulating valve z (44), and flow regulating valve a1 (34) are electrically connected to the control system respectively.

6. A cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 5, characterized in that: The liquid nitrogen washing tower (2), deargon tower (4), denitrification tower (8), demethanization tower (11), high-purity methane tower (15), and high-purity carbon monoxide tower (18) are packed towers or plate towers.

7. A method for producing high-purity electronic-grade carbon monoxide and methane by cryogenic separation, characterized in that: The cryogenic separation device for producing high-purity carbon monoxide and methane according to claim 6 specifically comprises the following steps: S1, the purified raw gas enters the raw gas channel (A3) of the main heat exchanger (1) through the external raw gas pipeline, and is The refluxed low-temperature gas is cooled and partially condensed to -180°C before entering the bottom of the liquid nitrogen scrubber (2). In the liquid nitrogen scrubber (2), the raw gas is condensed and scrubbed by the liquid nitrogen flowing from top to bottom, and hydrogen-rich gas with a CO content of less than 10 ppm is obtained at the top of the liquid nitrogen scrubber (2), and hydrogen-poor liquid is obtained at the bottom of the liquid nitrogen scrubber (2). S2, the hydrogen-poor liquid flows to ~0.55MPa through the liquid level regulating valve k (26) and then enters the low-temperature separator (3). After being throttled by the pressure regulating valve s (27), it is merged into the inlet pipeline of the nitrogen-rich gas I channel (A7). The liquid at the bottom of the low-temperature separator (3) passes through the liquid level regulating valve l (25) and returns to the hydrogen-poor liquid channel (A13) of the main heat exchanger (1) to be reheated to about ~-152℃, and then sent to the middle part of the demethanizer (11) for the second distillation. S3, after further distillation and demethanization in the demethanizer (11), CO, N2 and Ar in the bottom liquid are distilled to obtain methane liquid, which is throttled to ~0.2MPa by the liquid level regulating valve n (41) and then sent to the natural gas channel (A10) of the main heat exchanger (1) to be reheated to room temperature by the hot stream and used as external natural gas; the CO-rich gas obtained at the top of the demethanizer (11) enters the main condenser evaporator (12), and after condensation, enters the demethanizer reflux tank (13), the liquid refluxes to the top of the demethanizer (11), and the gas is sent to the middle of the deargon removal tower (4) for a third distillation; S4, further distilling the argon and oxygen through the de-argon tower (4), the argon-rich liquid obtained at the bottom is throttled by the liquid level regulating valve m (30) and then merged into the nitrogen-rich gas I channel (A7) inlet pipeline; the argon-lean gas obtained at the top enters the argon-lean gas channel (B2) to be cooled and partially condensed, and enters the de-argon tower reflux tank (7) for gas-liquid separation, the separated liquid phase is completely refluxed to the de-argon tower (4), and the separated gas phase (whose Ar content is ≤50ppm) is sent to the middle of the de-nitrogen tower (8) for the fourth distillation; S5, the gas phase separated from the reflux tank (7) of the de-argon tower is further distilled and denitrified by the de-nitrogenation tower (8), and the nitrogen-rich gas obtained at the top of the de-nitrogenation tower (8) returns to the nitrogen-rich gas I channel (A7) of the main heat exchanger (1), is reheated to room temperature by the hot stream, and then is discharged from the cold box under the conditions of 0.2MPa and 31°C as the external nitrogen-rich gas; the CO liquid obtained at the bottom of the de-nitrogenation tower (8) is throttled to 0.12MPa by the liquid level regulating valve o (35) and enters the carbon monoxide II channel (C2) of the de-nitrogenation tower condenser (9) to provide a cold source, and then returns to the carbon monoxide I channel (A5) of the main heat exchanger (1), is reheated to room temperature by the hot stream, and then is discharged from the cold box; S6, high-purity methane tower (15) and high-purity carbon monoxide tower (18), used to produce high-purity methane with a purity of ≥99 .999% high-purity methane and high-purity CO; the methane-rich gas from the middle of the demethanizer (11) is regulated by the flow regulating valve z (44) and enters the middle of the high-purity methane tower (15). A high-purity methane tower reboiler (16) is provided at the bottom of the high-purity methane tower (15) to distill the CO, N2 and Ar in the bottom liquid LNG to obtain a high-purity methane liquid with a purity of ≥99.999%. After being regulated by the liquid level regulating valve p (40), it is sent to the high-purity electronic grade methane channel (A9) of the main heat exchanger (1) and is reheated to room temperature by the hot stream to be used as external high-purity electronic grade 5N methane; through the above distillation, a methane-rich gas containing N2, CO and Ar is obtained at the top of the high-purity methane tower (15), and is then regulated by the pressure regulating valve v (45) and is also sent to the natural gas channel (A1) of the main heat exchanger (1). 0) is reheated to room temperature by the hot stream and used as natural gas for external transmission; the nitrogen-rich gas obtained from the top of the denitrification tower (8) is taken out through the flow regulating valve a1 (34) to enter the middle of the high-purity carbon monoxide tower (18) for further distillation, and the N2 and H2 in the liquid CO at the bottom are distilled to obtain high-purity CO liquid with a purity of ≥99.999%, which is then sent to the high-purity electronic grade CO channel (A8) of the main heat exchanger (1) after being regulated by the liquid level regulating valve q (48) and is reheated to room temperature by the hot stream as high-purity electronic grade 5N CO for external transmission; through the above distillation, nitrogen-rich gas containing H2 and CO is obtained at the top of the high-purity carbon monoxide tower (18), which is then regulated by the pressure regulating valve w (36) and is also sent to the nitrogen-rich gas I channel (A7) of the main heat exchanger (1) and is reheated to room temperature by the hot stream as nitrogen-rich gas; S7, nitrogen is compressed to 2.8MPa and cooled to about 40℃ by the nitrogen compressor system (21) and then enters the high-pressure nitrogen channel of the main heat exchanger (1). It is cooled, condensed and supercooled to -180℃ by the reflux low-temperature gas and then divided into four paths: the first path is throttled by the flow control valve y (28) and sent to the top of the liquid nitrogen washing tower (2) to wash and condense the CO component in the hydrogen-rich gas; the second path is throttled by the temperature control valve d (32), the temperature control valve e (33) and the temperature control valve g (37) and then enters the de-argon tower condenser (6), the de-nitrogen tower condenser (9) and the high-purity methane tower condenser (17) respectively to provide cooling capacity and then is vaporized, and the low-pressure nitrogen exits each tower The third liquid nitrogen is throttled by the temperature regulating valve b (24) and then merged with the low-pressure nitrogen coming out of each tower top condenser. The low-pressure nitrogen returns to the low-pressure nitrogen I channel (A2) of the main heat exchanger (1) and is reheated to room temperature by the hot stream before exiting the cold box and returning to the secondary inlet of the nitrogen compressor system (21). The fourth liquid nitrogen is throttled by the temperature regulating valve j (39) and then enters the high-purity carbon monoxide tower condenser (20) to provide cooling capacity and then is vaporized into low-low-pressure nitrogen. The low-low-pressure nitrogen returns to the low-low-pressure nitrogen channel (A4) of the main heat exchanger (1) and is reheated to room temperature by the hot stream before exiting the cold box and returning to the primary inlet of the nitrogen compressor system (21) to be compressed again for circulating refrigeration.

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