Device and method for preparing high-pressure CO through nitrogen throttling expansion CO pump pressurization dehydrogenation

Abstract

The invention discloses a device and a method for preparing high-pressure CO through nitrogen throttling expansion CO pump pressurization dehydrogenation, and belongs to the technical field of chemical cryogenic separation. The device comprises a nitrogen circulation compressor, and a first heat exchanger, a second heat exchanger, a stripping tower reboiler, a hydrogen-rich gas flash tank, a stripping tower, a CO liquid pump and a nitrogen expansion machine which are arranged in a cold box. The nitrogen circulation compressor participates in cold box circulation refrigeration, and the nitrogen expansion machine provides cold energy supplement. Purified gas from the upstream is cooled by the first heat exchanger, the stripping tower reboiler and the second heat exchanger in sequence and then enters the hydrogen-rich gas flash tank; a liquid phase at the bottom of the hydrogen-rich gas flash tank enters a stripping tower for continuous separation; a liquid phase at the bottom of the stripping tower is sequentially pressurized by the CO liquid pump and reheated by the first heat exchanger and then is discharged out of the cold box, so that a high-pressure CO product is obtained, and a conventional CO multi-stage circulating compressor is replaced. The system compression efficiency can be improved, the equipment cost is reduced, the equipment complexity is simplified, and the construction period is shortened.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical cryogenic separation technology, and particularly relates to a device and method for preparing high-pressure CO by nitrogen throttling expansion CO pump pressurization dehydrogenation. BACKGROUND

[0002] Carbon monoxide is a key raw material for synthesizing methanol, acetic acid, ethylene glycol and other organic chemicals, and is also a typical by-product component in tail gas of blast furnace ironmaking, coal gasification and petroleum processing industries. However, these by-product gases usually contain a large amount of hydrogen, nitrogen, methane and other components, which need to be further purified and separated to obtain high-purity CO products.

[0003] HyCO cryogenic separation is the main way to obtain CO products on a large scale in the current industry. The process system utilizes the boiling point difference of different gas components to achieve high-purity separation of CO through cryogenic liquefaction and low-temperature rectification. Among them, the single-tower separation process is connected with a stripping tower after a hydrogen-rich flash tank, which can effectively remove hydrogen in the raw gas, and has higher applicability for gas sources with low requirements for nitrogen and methane content in the CO product gas.

[0004] Since CO is generally required to be supplied at medium-high pressure when used as a raw material for downstream synthesis reactions, the low-pressure CO product from the cold box needs to be pressurized after cryogenic separation to meet the downstream process requirements. The existing conventional process often uses a CO multi-stage compression system to pressurize the product gas. However, the CO multi-stage compression system used in this method has a complex structure, requires a large power motor and a cooling device, has high equipment investment and operation cost, and requires high sealing and safety requirements for the equipment due to the toxicity of CO.

[0005] Therefore, it is a key technical problem to be solved to design a simplified HyCO separation dehydrogenation system to reduce equipment cost and system complexity while ensuring efficient separation of CO. SUMMARY

[0006] The purpose of the present application is to solve the problems of the prior art and provide a device and method for preparing high-pressure CO by nitrogen throttling expansion CO pump pressurization dehydrogenation.

[0007] The specific technical solutions adopted by the present application are as follows:

[0008] In a first aspect, the present application provides a device for preparing high-pressure CO by nitrogen throttling expansion CO pump pressurization dehydrogenation, comprising a nitrogen circulation compressor and a first heat exchanger, a second heat exchanger, a stripping tower reboiler, a hydrogen-rich flash tank, a stripping tower, a CO liquid pump and a nitrogen expander arranged in a cold box.

[0009] The purified gas from the upstream passes through the first heat exchanger, the stripping tower reboiler and the second heat exchanger in sequence, and then enters the hydrogen-rich gas flash tank after being cooled; the liquid phase at the bottom of the hydrogen-rich gas flash tank enters the stripping tower for further separation; the liquid phase at the bottom of the stripping tower is pressurized by the CO liquid pump, and then is warmed by the first heat exchanger, and then is discharged from the cold box and connected with the high-pressure CO product recovery device outside; the nitrogen circulation compressor provides nitrogen circulation refrigeration for the cold box, and the nitrogen expander provides cold energy supplement.

[0010] As preferred, the specific structure is as follows: the first hot side inlet of the first heat exchanger receives the purified gas from the upstream, the first cold side outlet of the first heat exchanger is connected with the hot side inlet of the stripping tower reboiler through a pipeline; the cold side outlet of the stripping tower reboiler is connected with the two-phase inlet of the hydrogen-rich gas flash tank through the first hot side inlet of the second heat exchanger and the first cold side outlet of the second heat exchanger in sequence;

[0011] The hydrogen-rich gas outlet of the hydrogen-rich gas flash tank is connected with the cold box outside through the first cold side inlet of the second heat exchanger, the first hot side outlet of the second heat exchanger, the first cold side inlet of the first heat exchanger and the first hot side outlet of the first heat exchanger in sequence, and is connected with the hydrogen-rich gas recovery device outside; the liquid phase outlet at the bottom of the hydrogen-rich gas flash tank is connected with the feed inlet of the stripping tower through a pipeline;

[0012] The flash steam outlet at the top of the stripping tower is connected with the cold box outside through the second cold side inlet of the second heat exchanger, the second hot side outlet of the second heat exchanger, the second cold side inlet of the first heat exchanger and the second hot side outlet of the first heat exchanger in sequence, and is connected with the flash steam recovery device outside; the liquid phase outlet at the bottom of the stripping tower is connected with the inlet of the CO liquid pump through a pipeline; the outlet of the CO liquid pump is divided into two branches, one branch is connected with the gas phase space at the bottom of the stripping tower through a pipeline, and the other branch is connected with the cold box outside through the third cold side inlet of the first heat exchanger and the third hot side outlet of the first heat exchanger in sequence, and is connected with the high-pressure CO product recovery device outside.

[0013] Further, a throttle valve is arranged on the pipeline between the liquid phase outlet at the bottom of the hydrogen-rich gas flash tank and the feed inlet of the stripping tower.

[0014] Further, a pressure regulating valve is arranged on the pipeline between the outlet of the CO liquid pump and the gas phase space of the stripping tower.

[0015] Further, a flow regulating valve is arranged on the pipeline between the third hot side outlet of the first heat exchanger and the high-pressure CO product recovery device outside.

[0016] Further, the nitrogen circulation refrigeration is as follows:

[0017] The final stage outlet of the nitrogen cycle compressor is divided into two branches. The first branch passes through the second hot-side inlet and the second cold-side outlet of the first heat exchanger and then divides into three branches. The first branch passes through the third cold-side inlet, the third hot-side outlet, the fourth cold-side inlet, and the fourth hot-side outlet of the second heat exchanger in sequence and then connects to the third-stage inlet of the nitrogen cycle compressor. The second branch passes through the fourth cold-side inlet, the fourth hot-side outlet, the fifth cold-side inlet, and the fifth hot-side outlet of the first heat exchanger in sequence and then connects to the second-stage inlet of the nitrogen cycle compressor. The third branch passes through the fifth cold-side inlet, the fifth hot-side outlet, the sixth cold-side inlet, and the sixth hot-side outlet of the first heat exchanger in sequence and then connects to the first-stage inlet of the nitrogen cycle compressor.

[0018] The second branch of the nitrogen cycle compressor's final stage outlet passes sequentially through the booster end of the nitrogen expander, the third hot-side inlet of the first heat exchanger, the third cold-side outlet of the first heat exchanger, and the expansion end of the nitrogen expander before connecting to the fourth cold-side inlet of the first heat exchanger.

[0019] Furthermore, a throttling valve is provided on the pipe between the second cold-side outlet of the first heat exchanger and the third cold-side inlet of the second heat exchanger.

[0020] Furthermore, a throttling valve is provided on the pipe between the second cold-side outlet of the first heat exchanger and the fourth cold-side inlet of the second heat exchanger.

[0021] Furthermore, a throttling valve is provided on the pipe between the second cold-side outlet of the first heat exchanger and the fifth cold-side inlet of the second heat exchanger.

[0022] Secondly, the present invention provides a method for preparing high-pressure CO using the apparatus for pressurized dehydrogenation of a nitrogen-throttling expansion CO pump as described in the first aspect, as follows:

[0023] The purified gas from upstream enters the first heat exchanger through a pipeline to cool down and then enters the stripping tower reboiler to provide heat for the stripping tower. After cooling down, the purified gas enters the hydrogen-rich flash tank for separation after being further cooled by the second heat exchanger.

[0024] The hydrogen-rich gas at the top of the hydrogen-rich flash tank is reheated by the second heat exchanger and the first heat exchanger in sequence to obtain room temperature hydrogen-rich gas exiting the cold box; the liquid phase at the bottom of the hydrogen-rich flash tank is throttled and then enters the stripping tower for dehydrogenation treatment.

[0025] The low-temperature flash vapor at the top of the stripping tower is reheated by the second heat exchanger and the first heat exchanger in sequence, and then the ambient temperature flash vapor exits the cold box; the liquid phase at the bottom of the stripping tower is increased to the product pressure by the CO liquid pump and then enters the first heat exchanger for reheating, and the high-pressure CO product exits the cold box.

[0026] The circulating nitrogen from the nitrogen circulating compressor is divided into two branches, one part of the circulating nitrogen is divided into three branches after being cooled by the first heat exchanger, and then enters the second heat exchanger and the first heat exchanger in turn to provide different temperature zones of the cold box with cold energy, and then is discharged from the cold box and returns to the gas inlet of each stage of the nitrogen circulating compressor to provide cold energy for the cold box; the other part of the circulating nitrogen is pressurized by the pressurizing end of the nitrogen expander in turn, then is cooled by the first heat exchanger, and then is expanded by the expansion end of the nitrogen expander to refrigerate, and then is converged with the circulating nitrogen from the second heat exchanger to enter the first heat exchanger to provide additional cold energy for the cold box.

[0027] The present application optimizes the process flow of the existing HyCO dehydrogenation device, and has the following beneficial effects compared with the prior art:

[0028] (1) The present application uses a CO liquid pump to directly pressurize the liquid CO from the bottom of the stripping tower to the required pressure of the product, and outputs the cold box after being reheated, instead of the original process of first reheating the liquid CO to output the cold box and then compressing it by multiple stages. This improvement eliminates the CO multi-stage compression system, not only simplifying the device structure, but also significantly reducing the equipment cost of the CO liquid pump compared with the multi-stage compressor, and the maintenance is more convenient.

[0029] (2) Since the CO liquid pump has a low cost advantage, a one-for-one backup operation scheme can be reasonably configured. When one pump needs maintenance, the backup pump can be switched to continue operation, so that the device can be maintained without stopping, effectively ensuring the continuity of production and the flexibility of operation.

[0030] (3) The present application uses a nitrogen circulating compression system to provide basic cold energy for the cold box, and additionally provides a nitrogen expander to supplement the cold energy by expanding part of the circulating nitrogen. Nitrogen is an inert gas with high safety; at the same time, the nitrogen circulating compressor has high efficiency and low operating cost, and there are many types of machines available on the market with short delivery cycle, providing greater flexibility for device configuration and optimization. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The process flow diagram of the device for preparing high-pressure CO by nitrogen throttling and expanding CO pump pressurization dehydrogenation provided by the present application is shown in the figure;

[0032] Figure 2 The process flow diagram of the device for preparing high-pressure CO by nitrogen throttling and expanding CO pump pressurization dehydrogenation preferred in the present embodiment is shown in the figure;

[0033] Figure 3 The local schematic diagram of the nitrogen circulating refrigeration in the present embodiment is shown in the figure;

[0034] In the diagram: 1. First heat exchanger; 2. Second heat exchanger; 3. Stripping tower reboiler; 4. Hydrogen-rich flash tank; 5. Stripping tower; 6. CO liquid pump; 7. Nitrogen cycle compressor; 8. Nitrogen expander. Detailed Implementation

[0035] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0036] In the description of this invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0037] In the description of this invention, it should be understood that the terms "low temperature", "normal temperature", "low pressure" and "high pressure" refer to the temperature or pressure relative to the same medium in the same passage, and should not be construed as indicating or implying relative importance or implicitly specifying the temperature and pressure values ​​of the indicated technical features.

[0038] like Figure 1 As shown in the preferred embodiment of the present invention, this embodiment provides an apparatus for pressurized dehydrogenation of CO using a nitrogen-throttling expansion CO pump to produce high-pressure CO. The apparatus includes a nitrogen circulating compressor 7, a first heat exchanger 1, a second heat exchanger 2, a stripping tower reboiler 3, a hydrogen-rich flash tank 4, a stripping tower 5, a CO liquid pump 6, and a nitrogen expander 8, all housed within a cold box. The nitrogen expander 8 comprises a pressurization end and an expansion end. The expansion end is the core component of the nitrogen expander 8, primarily reducing the pressure to lower the nitrogen gas temperature and generate cooling. The pressurization end increases the nitrogen pressure, resulting in a higher pressure entering the expansion end, a larger expansion ratio per unit working fluid, and thus a greater temperature drop and cooling capacity, significantly improving the energy efficiency of the entire expander and even the air separation unit.

[0039] In the apparatus provided by this invention, purified gas from upstream passes sequentially through a first heat exchanger 1, a stripping tower reboiler 3, and a second heat exchanger 2 for cooling before entering a hydrogen-rich flash tank 4. The liquid phase at the bottom of the hydrogen-rich flash tank 4 enters a stripping tower 5 for further separation. The liquid phase at the bottom of the stripping tower 5 is then pressurized by a CO liquid pump 6, reheated by the first heat exchanger 1, and exits into a cold box, where it connects to an external high-pressure CO product recovery device. Using the CO liquid pump 6 to pressurize the product while CO is in a liquid state replaces the conventional CO multi-stage circulating compressor for pressurizing CO products, thereby improving system compression efficiency, reducing equipment costs, simplifying equipment complexity, and shortening the construction period.

[0040] The connection mode of each component in the device provided in the embodiment is described in detail as follows:

[0041] In the device provided in the embodiment, the first hot side inlet of the first heat exchanger 1 receives the purified gas from the upstream, and the first cold side outlet of the first heat exchanger 1 is communicated with the hot side inlet of the stripping column reboiler 3 through a pipeline. The cold side outlet of the stripping column reboiler 3 is sequentially communicated with the two-phase inlet of the hydrogen-rich gas flash tank 4 through the first hot side inlet of the second heat exchanger 2 and the first cold side outlet of the second heat exchanger 2.

[0042] In the device provided in the embodiment, the hydrogen-rich gas outlet of the hydrogen-rich gas flash tank 4 is sequentially communicated with the outside hydrogen-rich gas recovery device through the first cold side inlet of the second heat exchanger 2, the first hot side outlet of the second heat exchanger 2, the first cold side inlet of the first heat exchanger 1, and the first hot side outlet of the first heat exchanger 1.

[0043] In the device provided in the embodiment, the liquid phase outlet at the bottom of the hydrogen-rich gas flash tank 4 is communicated with the feed inlet of the stripping column 5 through a pipeline provided with a throttling valve. The flash steam outlet at the top of the stripping column 5 is sequentially communicated with the outside flash steam recovery device through the second cold side inlet of the second heat exchanger 2, the second hot side outlet of the second heat exchanger 2, the second cold side inlet of the first heat exchanger 1, and the second hot side outlet of the first heat exchanger 1.

[0044] In the device provided in the embodiment, the liquid phase outlet at the bottom of the stripping column 5 is communicated with the inlet of the CO liquid pump 6 through a pipeline. The outlet of the CO liquid pump 6 is divided into two branches, one branch is communicated with the gas phase space at the bottom of the stripping column 5 through a pipeline, and the other branch is sequentially communicated with the outside high-pressure CO product recovery device through the third cold side inlet of the first heat exchanger 1 and the third hot side outlet of the first heat exchanger 1. It should be noted that, as a preferred embodiment of the present application, a pressure control regulating valve is arranged on the pipeline through which the outlet of the CO liquid pump 6 is communicated with the gas phase space of the stripping column 5, to indicate and control the pressure of the CO gas. A flow control regulating valve is arranged on the pipeline through which the third hot side outlet of the first heat exchanger 1 is connected with the outside high-pressure CO product recovery device, to indicate and control the flow of the high-pressure CO product gas, as shown in Figure 2

[0045] In the device provided in the embodiment, the nitrogen circulation compressor 7 provides nitrogen circulation refrigeration for the cold box, as shown in Figure 3

[0046] ​​The outlet of the last stage of the nitrogen circulation compressor 7 is divided into two branches. The first branch passes through the second hot side inlet of the first heat exchanger 1 and the second cold side outlet of the first heat exchanger 1, and is divided into three branches. The first branch passes through the third cold side inlet of the second heat exchanger 2, the third hot side outlet of the second heat exchanger 2, the fourth cold side inlet of the first heat exchanger 1, and the fourth hot side outlet of the first heat exchanger 1 in sequence, and then communicates with the third stage inlet of the nitrogen circulation compressor 7. A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger 1 and the third cold side inlet of the second heat exchanger 2.

[0047] The second branch passes through the fourth cold side inlet of the second heat exchanger 2, the fourth hot side outlet of the second heat exchanger 2, the fifth cold side inlet of the first heat exchanger 1, and the fifth hot side outlet of the first heat exchanger 1 in sequence, and then communicates with the second stage inlet of the nitrogen circulation compressor 7. A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger 1 and the fourth cold side inlet of the second heat exchanger 2.

[0048] The third branch passes through the fifth cold side inlet of the second heat exchanger 2, the fifth hot side outlet of the second heat exchanger 2, the sixth cold side inlet of the first heat exchanger 1, and the sixth hot side outlet of the first heat exchanger 1 in sequence, and then communicates with the first stage inlet of the nitrogen circulation compressor 7. A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger 1 and the fifth cold side inlet of the second heat exchanger 2.

[0049] The second branch of the outlet of the last stage of the nitrogen circulation compressor 7 passes through the pressurizing end of the nitrogen expander 8, the third hot side inlet of the first heat exchanger 1, the third cold side outlet of the first heat exchanger 1, the expansion end of the nitrogen expander 8 in sequence, and then communicates with the fourth cold side inlet of the first heat exchanger 1.

[0050] The embodiment also provides a method for preparing high-pressure CO by nitrogen throttling expansion using the above device, and the specific method is as follows:

[0051] (1) Precooling of purified gas

[0052] The purified gas (including CO and H2) from the upstream enters the first heat exchanger 1 to be cooled, then enters the stripping column reboiler 3, and provides heat for the stripping column 5 to partially vaporize. The cooled purified gas is further cooled by the second heat exchanger 2, and then enters the hydrogen-rich gas flash tank 4 for separation.

[0053] (2) Hydrogen rough separation and stripping refining

[0054] In the hydrogen-rich gas flash tank 4, the gas-liquid two-phase is preliminarily separated. The hydrogen-rich gas at the top of the hydrogen-rich gas flash tank 4 is sequentially heat-exchanged by the second heat exchanger 2 and the first heat exchanger 1, and then is warmed to room temperature and then is output from the cold box as a hydrogen-rich gas product.

[0055] The liquid phase at the bottom of the hydrogen-rich flash tank 4 is throttled by a throttle valve, and then enters the stripping column 5 for dehydrogenation. In the stripping column 5, the liquid phase flows downward and contacts the upward gas phase generated by the stripping column reboiler 3. The trace amount of hydrogen dissolved in the liquid is desorbed and discharged from the top of the column. The low-temperature flash gas at the top of the stripping column 5 is sequentially reheated by the second heat exchanger 2 and the first heat exchanger 1, and then the normal-temperature flash gas is discharged from the cold box as the flash gas product.

[0056] (3) Separation and output of high-pressure CO product

[0057] The high-purity liquid CO at the bottom of the stripping column 5 is pressurized by a CO liquid pump 6 to the product pressure. The pressurized high-pressure liquid CO is reheated by the first heat exchanger 1, and then the high-pressure CO product is discharged from the cold box. A flow control valve is arranged on the CO product output pipeline to ensure the stability of the product flow and the balance of the system pressure.

[0058] (4) Cold energy provided by the nitrogen circulation refrigeration system

[0059] The circulating nitrogen from the nitrogen circulation compressor 7 is divided into two branches. One part of the circulating nitrogen is pre-cooled by the first heat exchanger 1, and then is divided into three branches. After being throttled in stages, the circulating nitrogen is sequentially introduced into the second heat exchanger 2 and the first heat exchanger 1 to provide cold energy at different temperature zones for the cold box, and then is discharged from the cold box and returned to the respective inlet ports of the nitrogen circulation compressor 7 to provide cold energy for the cold box. The other part of the circulating nitrogen is first compressed to a higher pressure by the pressurizing end of the nitrogen expander 8, and then is cooled by the first heat exchanger 1. Subsequently, the high-pressure low-temperature nitrogen is introduced into the expanding end of the nitrogen expander 8 for expansion refrigeration. The expanded low-temperature low-pressure nitrogen is combined with the circulating nitrogen from the second heat exchanger 2, and then is introduced into the first heat exchanger 1 to provide additional cold energy for the cold box.

[0060] The above-described embodiment is only a preferred scheme of the present application, and is not intended to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, any technical scheme obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A device for producing high pressure CO by pressurized dehydrogenation using a nitrogen throttling expansion CO pump, characterized by, The nitrogen circulation compressor (7) and the first heat exchanger (1), the second heat exchanger (2), the stripping tower reboiler (3), the hydrogen-rich gas flash tank (4), the stripping tower (5), the CO liquid pump (6) and the nitrogen expander (8) arranged in the cold box are included. The purified gas from the upstream is sequentially cooled by the first heat exchanger (1), the stripping tower reboiler (3) and the second heat exchanger (2) and then enters the hydrogen-rich gas flash tank (4); the liquid phase at the bottom of the hydrogen-rich gas flash tank (4) enters the stripping tower (5) for further separation; the liquid phase at the bottom of the stripping tower (5) is sequentially pressurized by the CO liquid pump (6) and warmed by the first heat exchanger (1) and then discharged from the cold box and communicated with the high-pressure CO product recovery device outside; the nitrogen circulation compressor (7) provides nitrogen circulation refrigeration for the cold box, and the nitrogen expander (8) provides cold energy supplement.

2. The apparatus for producing high pressure CO by pressurized dehydrogenation using nitrogen throttling expansion CO pump according to claim 1, wherein The specific structure is as follows: The first hot side inlet of the first heat exchanger (1) receives the purified gas from the upstream, and the first cold side outlet of the first heat exchanger (1) is communicated with the hot side inlet of the stripping tower reboiler (3) through a pipeline; the cold side outlet of the stripping tower reboiler (3) is sequentially communicated with the two-phase inlet of the hydrogen-rich gas flash tank (4) through the first hot side inlet of the second heat exchanger (2) and the first cold side outlet of the second heat exchanger (2); The hydrogen-rich gas outlet of the hydrogen-rich gas flash tank (4) is sequentially communicated with the high-pressure hydrogen-rich gas recovery device outside through the first cold side inlet of the second heat exchanger (2), the first hot side outlet of the second heat exchanger (2), the first cold side inlet of the first heat exchanger (1) and the first hot side outlet of the first heat exchanger (1) after being discharged from the cold box; the liquid phase outlet at the bottom of the hydrogen-rich gas flash tank (4) is communicated with the feed inlet of the stripping tower (5) through a pipeline; The flash steam outlet at the top of the stripping tower (5) is sequentially communicated with the flash steam recovery device outside through the second cold side inlet of the second heat exchanger (2), the second hot side outlet of the second heat exchanger (2), the second cold side inlet of the first heat exchanger (1) and the second hot side outlet of the first heat exchanger (1) after being discharged from the cold box; the liquid phase outlet at the bottom of the stripping tower (5) is connected with the inlet of the CO liquid pump (6) through a pipeline; the outlet of the CO liquid pump (6) is divided into two branches, one branch is communicated with the gas phase space at the bottom of the stripping tower (5) through a pipeline, and the other branch is sequentially communicated with the high-pressure CO product recovery device outside through the third cold side inlet of the first heat exchanger (1) and the third hot side outlet of the first heat exchanger (1) after being discharged from the cold box.

3. The apparatus for pressurized dehydrogenation for producing high pressure CO by nitrogen throttling expansion CO pump according to claim 2, characterized in that, A throttling valve is arranged on the pipeline between the liquid phase outlet at the bottom of the hydrogen-rich gas flash tank (4) and the feed inlet of the stripping tower (5).

4. The apparatus for pressurized dehydrogenation for producing high pressure CO by nitrogen throttling expansion CO pump according to claim 2, characterized in that, A pressure regulating valve is arranged on the pipeline through which the outlet of the CO liquid pump (6) is communicated with the gas phase space of the stripping tower (5).

5. The apparatus for pressurized dehydrogenation for the production of high pressure CO by nitrogen throttling expansion CO pump as claimed in claim 2, wherein, A flow regulating valve is arranged on the pipeline through which the third hot side outlet of the first heat exchanger (1) is connected with the high-pressure CO product recovery device outside.

6. The apparatus for pressurized dehydrogenation for the production of high pressure CO by nitrogen throttling expansion CO pump as claimed in claim 2 wherein, The nitrogen circulation refrigeration is specifically as follows: The last stage outlet of the nitrogen circulation compressor (7) is divided into two branches, the first branch passes through the second hot side inlet of the first heat exchanger (1) and the second cold side outlet of the first heat exchanger (1) and is divided into three branches, the first branch passes through the third cold side inlet of the second heat exchanger (2), the third hot side outlet of the second heat exchanger (2), the fourth cold side inlet of the first heat exchanger (1) and the fourth hot side outlet of the first heat exchanger (1) in sequence and is communicated with the third stage gas inlet of the nitrogen circulation compressor (7); the second branch passes through the fourth cold side inlet of the second heat exchanger (2), the fourth hot side outlet of the second heat exchanger (2), the fifth cold side inlet of the first heat exchanger (1) and the fifth hot side outlet of the first heat exchanger (1) in sequence and is communicated with the second stage gas inlet of the nitrogen circulation compressor (7); the third branch passes through the fifth cold side inlet of the second heat exchanger (2), the fifth hot side outlet of the second heat exchanger (2), the sixth cold side inlet of the first heat exchanger (1) and the sixth hot side outlet of the first heat exchanger (1) in sequence and is communicated with the first stage gas inlet of the nitrogen circulation compressor (7); The second branch of the last stage outlet of the nitrogen circulation compressor (7) passes through the pressurizing end of the nitrogen expander (8), the third hot side inlet of the first heat exchanger (1), the third cold side outlet of the first heat exchanger (1), the expansion end of the nitrogen expander (8) in sequence and is communicated with the fourth cold side inlet of the first heat exchanger (1).

7. The apparatus for pressurized dehydrogenation for producing high pressure CO by nitrogen throttling expansion CO pump according to claim 6, characterized in that, A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger (1) and the third cold side inlet of the second heat exchanger (2).

8. The apparatus for pressurized dehydrogenation for producing high pressure CO by nitrogen throttling expansion CO pump according to claim 6, characterized in that, A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger (1) and the fourth cold side inlet of the second heat exchanger (2).

9. The apparatus for pressurized dehydrogenation for producing high pressure CO by nitrogen throttling expansion CO pump according to claim 6, characterized in that, A throttle valve is arranged on the pipeline between the second cold side outlet of the first heat exchanger (1) and the fifth cold side inlet of the second heat exchanger (2).

10. A method for producing high pressure CO by using the device for producing high pressure CO by pressure dehydrogenation of CO according to any one of claims 1 to 9, characterized in that, Specifically as follows: The purified gas from the upstream enters the first heat exchanger (1) to be cooled, then enters the stripping column reboiler (3) to provide heat for the stripping column (5); the cooled purified gas further passes through the second heat exchanger (2) to be cooled and then enters the hydrogen-rich gas flash tank (4) for separation; The hydrogen-rich gas at the top of the hydrogen-rich gas flash tank (4) passes through the second heat exchanger (2) and the first heat exchanger (1) in sequence to be reheated and then the normal-temperature hydrogen-rich gas is discharged from the cold box; the liquid phase at the bottom of the hydrogen-rich gas flash tank (4) is throttled and then enters the stripping column (5) for dehydrogenation treatment; The low-temperature flash steam at the top of the stripping column (5) passes through the second heat exchanger (2) and the first heat exchanger (1) in sequence to be reheated and then the normal-temperature flash steam is discharged from the cold box; the liquid phase at the bottom of the stripping column (5) is increased to the product pressure by the CO liquid pump (6) and then enters the first heat exchanger (1) to be rewarmed and then the high-pressure CO product is discharged from the cold box; The circulating nitrogen from the nitrogen circulating compressor (7) is divided into two branches, one part of the circulating nitrogen is cooled by the first heat exchanger (1) and then divided into three branches, after being throttled in stages, the circulating nitrogen enters the second heat exchanger (2) and the first heat exchanger (1) in turn to provide cold energy for the cold box at different temperature zones and then leaves the cold box, and returns to the nitrogen circulating compressor (7) respectively to provide cold energy for the cold box; the other part of the circulating nitrogen is pressurized by the pressurizing end of the nitrogen expander (8) in turn, cooled by the first heat exchanger (1), expanded by the expanding end of the nitrogen expander (8) to refrigerate, and then merged with the circulating nitrogen from the second heat exchanger (2) to enter the first heat exchanger (1) to provide additional cold energy for the cold box.

Images