CN209840521U

CN209840521U - Equipment for separating and purifying carbon monoxide

Info

Publication number: CN209840521U
Application number: CN201920729586.3U
Authority: CN
Inventors: 张惊涛; 王子松
Original assignee: Chengdu Sepmem Sci & Tech Co Ltd
Current assignee: Chengdu Sepmem Sci & Tech Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2019-12-24
Anticipated expiration: 2029-05-17

Abstract

The utility model provides a device for separating and purifying carbon monoxide. The utility model discloses an equipment of separation and purification carbon monoxide makes partly compressed carbon monoxide flow back extremely as backward flow carbon monoxide through set up return line between carbon monoxide compressor and knockout tower in the knockout tower, this part backward flow carbon monoxide can release cold volume after throttling and step-down, provides required cold volume for the synthetic gas cooling to do not need extra external liquid nitrogen of introducing from equipment to supply cold volume, this equipment not only is applicable to the operating mode that carbon monoxide content is high and pressure is high in the synthetic gas, is applicable to the operating mode that carbon monoxide content is low and pressure is low in the synthetic gas moreover, and application scope is wide.

Description

Equipment for separating and purifying carbon monoxide

Technical Field

The utility model relates to a gas separation technical field especially relates to a separation and purification carbon monoxide's equipment.

Background

As an important oxo feed gas, carbon monoxide (CO) can be used to make almost all organic chemicals, such as methanol, formic acid, methylamine, acetic acid, isocyanates, oxalic acid, ethylene glycol, dimethyl carbonate, phosgene, and agricultural herbicides.

The synthesis gas uses carbon monoxide and hydrogen as main components and is used as a raw material gas of chemical raw materials. The raw material range of the synthesis gas is wide, and the synthesis gas can be generated by gasifying solid fuels such as coal or coke, can be prepared from light hydrocarbons such as natural gas and naphtha, and can be produced from heavy oil by a partial oxidation method.

The low temperature separation technology is used in industry to obtain high purity carbon monoxide with large treatment capacity from synthesis gas. The existing technology for extracting carbon monoxide and hydrogen products from synthesis gas by low-temperature separation mostly utilizes the self pressure of the synthesis gas to throttle and reduce pressure, and provides cold energy for raw material gas separation and carbon monoxide purification. However, the method is limited by the composition and pressure of raw material gas, when the cold energy provided by throttling and depressurizing the carbon monoxide separated by the method is insufficient, the cold energy is supplemented by filling liquid nitrogen, the application range of the method is limited to a great extent, and the method is difficult to realize in some factories without air separation devices and liquid nitrogen products, that is, the existing method for purifying and separating the carbon monoxide from the synthesis gas has the defects of small adaptation range to the raw material gas, excessive dependence on the liquid nitrogen, high energy consumption and the like.

Therefore, it is very important to develop a low-temperature separation and purification technology of carbon monoxide, which is suitable for various raw material gas conditions, does not need liquid nitrogen, has low energy consumption and simple process.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a separation and purification carbon monoxide's equipment, when adopting this equipment purification to prepare carbon monoxide from the synthetic gas, do not need extra external liquid nitrogen of introducing of slave unit to supply cold volume, the independence is strong, and application scope is wide.

In order to achieve the above purpose, the utility model provides a device for separating and purifying carbon monoxide, which comprises a heat exchanger, a first gas-liquid separator, a separation tower, a second gas-liquid separator and a carbon monoxide compressor which are sequentially communicated through pipelines;

a throttling valve is arranged in a pipeline between the separation tower and the second gas-liquid separator and used for throttling, depressurizing and cooling the fluid;

a first heat exchange channel and a second heat exchange channel are arranged in the heat exchanger, the first heat exchange channel is used for enabling the synthesis gas to pass through and cooling the synthesis gas, and the second heat exchange channel is used for enabling the fluid which flows out of the separation tower and is subjected to throttling, pressure reduction and temperature reduction to pass through so as to release cold energy;

a return pipeline is arranged between the carbon monoxide compressor and the separation tower and is used for enabling a part of compressed carbon monoxide in the carbon monoxide compressor to be used as return carbon monoxide to flow back to the separation tower; and a third heat exchange channel is arranged in the heat exchanger, is positioned in the return pipeline and is used for cooling the returned carbon monoxide when the carbon monoxide passes through the return pipeline.

In some embodiments of the present invention, a reboiler is disposed at the bottom of the separation column.

In some embodiments of the present invention, the return line communicates to an inlet of the reboiler, and an outlet of the reboiler communicates to an upper portion or a middle portion of the separation column through a line.

In some embodiments of the present invention, the return line communicates to an upper or middle portion of the separation column;

the first heat exchange channel comprises a first heat exchange section and a second heat exchange section which are discontinuous, an outlet of the first heat exchange section is communicated to an inlet of the reboiler through a pipeline, an outlet of the reboiler is communicated to an inlet of the second heat exchange section through a pipeline, and an outlet of the second heat exchange section is communicated to the first gas-liquid separator through a pipeline.

In some embodiments of the present invention, the apparatus for separating and purifying carbon monoxide further comprises a first precooler, which is disposed upstream of the heat exchanger and is communicated with the heat exchanger through a pipeline.

In some embodiments of the present invention, the apparatus for separating and purifying carbon monoxide further comprises a second precooler, the second precooler is disposed in the return line and between the carbon monoxide compressor and the third heat exchange channel of the heat exchanger.

The utility model discloses an in some embodiments, the knockout tower with be equipped with a plurality of throttle depressurization pipelines between the heat exchanger, all be equipped with the choke valve in every throttle depressurization pipeline.

The utility model discloses an in some embodiments, be equipped with a plurality of second heat transfer passageways in the heat exchanger, a plurality of second heat transfer passageways correspond the intercommunication respectively a plurality of throttle step-down pipelines.

In some embodiments of the present invention, the apparatus for separating and purifying carbon monoxide further comprises a purification device disposed upstream of the heat exchanger.

The utility model discloses an in some embodiments, be equipped with fourth heat transfer passageway and fifth heat transfer passageway in the heat exchanger, fourth heat transfer passageway with the pipeline intercommunication is passed through at first vapour and liquid separator's top, fifth heat transfer passageway with the pipeline intercommunication is passed through at the top of knockout tower.

The utility model has the advantages that:

the utility model discloses an equipment of separation and purification carbon monoxide makes partly compressed carbon monoxide flow back extremely as backward flow carbon monoxide through set up return line between carbon monoxide compressor and knockout tower in the knockout tower, this part backward flow carbon monoxide can release cold volume after throttling and step-down, for the synthetic gas cooling provides required cold volume, does not need extra external introduction liquid nitrogen of follow equipment to supply cold volume, the utility model discloses an equipment not only is applicable to the operating mode that carbon monoxide content is high and pressure is high in the synthetic gas, is applicable to the operating mode that carbon monoxide content is low and pressure is low in the synthetic gas moreover, and application scope is wide.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a first embodiment of the apparatus for separating and purifying carbon monoxide according to the present invention;

fig. 2 is a schematic structural diagram of a second embodiment of the apparatus for separating and purifying carbon monoxide according to the present invention.

Description of the main element symbols:

10. a purification device; 21. a first precooler; 30. a heat exchanger; 31. a first heat exchange channel; 311. a first heat exchange section; 312. a second heat exchange section; 32. a second heat exchange channel; 33. a third heat exchange channel; 34. a fourth heat exchange channel; 35. a fifth heat exchange channel; 41. a first gas-liquid separator; 50. a separation column; 51. a reboiler; 42. a second gas-liquid separator; 60. a throttle valve; 70. a carbon monoxide compressor; 72. an intercooler; 22. a second precooler.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1 and 2, the present invention first provides an apparatus for separating and purifying carbon monoxide, which includes a heat exchanger 30, a first gas-liquid separator 41, a separation tower 50, a second gas-liquid separator 42 and a carbon monoxide compressor 70, which are sequentially connected through a pipeline;

a throttling valve 60 is arranged in a pipeline between the separation tower 50 and the second gas-liquid separator 42, and the throttling valve 60 is used for throttling, depressurizing and cooling the fluid;

a first heat exchange channel 31 and a second heat exchange channel 32 are arranged in the heat exchanger 30, the first heat exchange channel 31 is used for enabling the synthesis gas to pass through and cooling the synthesis gas, and the second heat exchange channel 32 is used for enabling the fluid which flows out of the separation tower 50 and is throttled, depressurized and cooled to pass through so as to release cold energy;

a return line is arranged between the carbon monoxide compressor 70 and the separation column 50, and the return line is used for returning a part of compressed carbon monoxide in the carbon monoxide compressor 70 to the separation column 50 as return carbon monoxide; a third heat exchange channel 33 is provided in the heat exchanger 30, and the third heat exchange channel 33 is located in the return line and is used for cooling the returned carbon monoxide as it passes therethrough.

The utility model discloses a working process of equipment of separation and purification carbon monoxide roughly:

a. after the synthesis gas enters the first heat exchange channel 31 of the heat exchanger 30 for cooling, the temperature is reduced to cause partial gas to be condensed, so as to form a first gas-liquid mixture, and the purpose of the synthesis gas entering the heat exchanger 30 for cooling is to condense all carbon monoxide in the synthesis gas into liquid as much as possible, so that a basis is provided for subsequent separation.

Specifically, the temperature of the first gas-liquid mixture formed after the synthesis gas is cooled by the first heat exchange channel 31 is-170 ℃ to-190 ℃.

b. The first gas-liquid mixture enters the first gas-liquid separator 41 for gas-liquid separation, and a first liquid phase located at the bottom of the first gas-liquid separator 41 and a first gas phase located above the first liquid phase are formed, and the first gas phase escapes from the top of the first gas-liquid separator 41, specifically, the first gas phase is mainly hydrogen, and a small amount of carbon monoxide is mixed with the first gas phase.

c. The first liquid phase is introduced into the separation tower 50, after the tower bottom is heated, the hydrogen in the first liquid phase is converted from liquid state to gas state to form a second gas phase, the second gas phase escapes from the tower top of the separation tower 50, and the liquid carbon monoxide is retained at the tower bottom of the separation tower 50 to form a second liquid phase, wherein the second gas phase is mainly hydrogen and is mixed with a small amount of carbon monoxide.

d. The second liquid phase flows out from the bottom of the separation tower 50, and then is throttled, depressurized and cooled by the throttle valve 60 to form a second gas-liquid mixture with low temperature and low pressure, the temperature of the second gas-liquid mixture is-140 ℃ to-180 ℃, when the second gas-liquid mixture directly enters the third heat exchange channel 33 of the heat exchanger 30 for cooling, the gas in the second gas-liquid mixture is easy to converge above the liquid to cause uneven gas-liquid mixing, and the cold energy carried by the gas and the liquid is different, so that the problem of uneven heat exchange can occur when the second gas-liquid mixture is directly introduced into the heat exchanger 30 for heat exchange, in order to avoid the problem, the utility model is provided with the second gas-liquid separator 42, which separates the gas and the liquid in the second gas-liquid mixture and then respectively introduces into the third heat exchange channel 33 of the heat exchanger 30 at a constant rate, the gas and the liquid are uniformly mixed, and the uniform heat exchange effect is realized.

e. When the second gas-liquid mixture releases cold through the third heat exchange channel 33, the second gas-liquid mixture is reheated, at this time, the second gas-liquid mixture is completely converted into carbon monoxide gas, and then the carbon monoxide gas enters the carbon monoxide compressor 70 to be compressed into a carbon monoxide product.

f. In order to make the utility model discloses an equipment of separation and purification carbon monoxide can realize cold volume self-sufficiency, avoids the cold volume that the throttle step-down cooling link of step d produced can not satisfy the demand of synthetic gas cooling in step a, the utility model discloses still set up and make backward flow carbon monoxide return to return pipeline in the knockout tower 50 sets up the aim at of this return pipeline: the amount of carbon monoxide fluid used for throttling depressurization can be increased, the cold energy released in the throttling depressurization link is increased, and sufficient cold energy is provided for cooling (condensing) of the synthesis gas in the heat exchanger 30.

Among the prior art, under the lower condition of feed gas CO content or feed gas pressure, the cold volume that produces after CO liquid throttle decompression can not satisfy the needs of synthetic gas cooling (condensation), the utility model discloses a partial CO backward flow after the extraction compression adopts the refrigerated principle of compression, for the cold volume that synthetic gas cooling (condensation) supply is not enough.

The utility model discloses a circulation CO provides poor cold volume that lacks, also can make equipment normal operating be suitable for under the operating mode that feed gas CO content is low, pressure is low, does not need extra supplementary liquid nitrogen, and the technology independence is strong, and application scope is wide.

In some embodiments of the present invention, the heat exchanger 30 is a plate-fin heat exchanger 30.

Specifically, the reflux carbon monoxide may be a carbon monoxide product, or carbon monoxide which is extracted in advance in the compression process and has a lower pressure than the carbon monoxide product, or in order to meet the requirements of supplementing cold energy and reducing energy consumption, the reflux carbon monoxide may also be carbon monoxide which has a pressure greater than that of the carbon monoxide product, and thus the compression stage number needs to be increased after the pressure of the carbon monoxide product is reached, and the carbon monoxide which needs to be refluxed is compressed to a higher pressure. The temperature of the reflux carbon monoxide is 30-40 ℃.

The utility model discloses in, the pressure of carbon monoxide product can be adjusted according to low reaches user's needs, how much and the minimum principle of energy consumption of the cold volume that the pressure of backward flow carbon monoxide can supply as required adjust, and the flexible operation is convenient.

Specifically, as shown in fig. 1 and fig. 2, the bottom of the separation column 50 is provided with a reboiler 51, and the reboiler 51 is used for heating the bottom liquid (i.e., the second liquid phase) to convert the hydrogen remaining in the bottom liquid from a liquid state to a gaseous state, and then the hydrogen escapes from the top of the separation column 50.

In some embodiments of the present invention, the reboiler 51 is immersed in the liquid at the bottom of the tower (i.e. the second liquid phase), and the heat medium (syngas or reflux carbon monoxide) flows inside the reboiler 51 to heat the liquid at the bottom of the tower.

As shown in fig. 1, in the first embodiment of the present invention, the return line is connected to the inlet of the reboiler 51, and the outlet of the reboiler 51 is connected to the upper part or the middle part of the separation column 50 through a pipeline. In this first embodiment, the reflux carbon monoxide first passes through the reboiler 51 to supply the heat required for heating in the bottom of the column, then enters the separation column 50 from the top of the column, and finally flows out from the bottom of the column to be throttled and depressurized for temperature reduction.

As shown in fig. 2, in the second embodiment of the present invention, the return line is connected to the upper part or the middle part of the separation column 50, and the fluid for supplying heat to the bottom of the separation column 50 is syngas in this second embodiment.

In this second embodiment, the first heat exchange channel 31 comprises a discontinuous first heat exchange section 311 and a discontinuous second heat exchange section 312, an outlet of the first heat exchange section 311 is communicated to an inlet of the reboiler 51 through a pipeline, an outlet of the reboiler 51 is communicated to an inlet of the second heat exchange section 312 through a pipeline, and an outlet of the second heat exchange section 312 is communicated to the first gas-liquid separator 41 through a pipeline.

In this second embodiment, the reflux carbon monoxide enters the separation column 50 and then directly flows out from the bottom of the column to be throttled, depressurized and cooled. The synthesis gas firstly enters the first heat exchange section 311 for first cooling, then enters the reboiler 51 via a pipeline to heat the tower bottoms, and then flows out of the reboiler 51 and enters the second heat exchange section 312 via a pipeline for second cooling. Specifically, the temperature of the synthesis gas after the second cooling is-170 ℃ to-190 ℃.

Specifically, the temperature of the bottom of the separation tower 50 is-160 ℃ to-180 ℃, and the temperature of the top of the separation tower 50 is-170 ℃ to-200 ℃.

Preferably, as shown in fig. 1, the apparatus for separating and purifying carbon monoxide further comprises a first precooler 21, and the first precooler 21 is arranged upstream of the heat exchanger 30 and is communicated with the heat exchanger 30 through a pipeline. The first precooler 21 is used for precooling the synthesis gas before the synthesis gas enters the heat exchanger 30 for cooling, and the temperature of the synthesis gas after precooling is 0 ℃ to-30 ℃, such as 0 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃ and 30 ℃.

Preferably, as shown in fig. 1, the apparatus for separating and purifying carbon monoxide further comprises a second precooler 22, and the second precooler 22 is arranged in the return line and is arranged between the carbon monoxide compressor 70 and the third heat exchange channel 33 of the heat exchanger 30. The first precooler 21 is used for precooling the reflux carbon monoxide before the reflux carbon monoxide enters the heat exchanger 30 for cooling, and the temperature after carbon monoxide precooling is 0-30 ℃, such as 0 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃ and 30 ℃.

The utility model discloses the volume that sets up first precooler 21 and second precooler 22 and aim at reduction backward flow carbon monoxide reduces the compression energy consumption of carbon monoxide (about 20 ~ 30%), practices thrift manufacturing cost.

Specifically, the throttling depressurization can be performed in multiple stages, that is, a plurality of throttling depressurization pipelines are arranged between the separation tower 50 and the heat exchanger 30, each throttling depressurization pipeline is provided with a throttling valve 60, and the second liquid phase (i.e., liquid carbon monoxide) flowing out from the bottom of the separation tower 50 enters the heat exchanger 30 through a plurality of branch pipelines, so that the liquid carbon monoxide can be throttled and depressurized in the plurality of throttling depressurization pipelines, and the carbon monoxide reduced to different pressures can release cold in different temperature regions.

In some embodiments of the present invention, a plurality of second heat exchanging passages 32 are disposed in the heat exchanger 30, and the plurality of second heat exchanging passages 32 correspond to and communicate with the plurality of throttling and depressurizing pipelines respectively.

In addition, by respectively controlling the throttle valves 60 in the throttling pressure reduction pipelines, different pressure reduction and temperature reduction effects can be realized in the throttling pressure reduction pipelines, so that the cold quantity requirements of the second heat exchange channels 32 with different temperature levels are met.

As shown in fig. 1 and fig. 2, in some embodiments of the present invention, the carbon monoxide compressor 70 has a plurality of compression stages, and the suction ports of the plurality of compression stages are respectively communicated with the plurality of second heat exchange passages 32, and are respectively used for compressing the carbon monoxide gas flowing out from the plurality of second heat exchange passages 32. In some embodiments of the present invention, a plurality of intercoolers 72 are provided between the plurality of compression stages of the carbon monoxide compressor 70.

As shown in fig. 1 and fig. 2, in an embodiment of the present invention, the throttling depressurization is performed in 2 stages, and the liquid carbon monoxide flowing out from the bottom of the separation tower 50 enters the heat exchanger 30 through 2 throttling depressurization pipelines, wherein 2 second heat exchange passages 32 are arranged in the heat exchanger 30, and the 2 second heat exchange passages 32 are respectively communicated with the 2 throttling depressurization pipelines. The carbon monoxide compressor 70 has 2 stages of suction ports, and the 2 suction ports are respectively used for sucking and compressing the carbon monoxide gas flowing out of the 2 second heat exchange passages 32.

Preferably, the apparatus for separating and purifying carbon monoxide further comprises a purification device 10 disposed upstream of the heat exchanger 30, wherein the purification device 10 is used for purifying the synthesis gas before the synthesis gas enters the heat exchanger 30, and removing harmful impurities, such as carbon dioxide, methanol, water, sulfides, mercury and the like, in the synthesis gas, which easily corrode the apparatus or easily cause freezing and blocking of the apparatus at low temperature.

In some embodiments of the present invention, a fourth heat exchanging channel 34 and a fifth heat exchanging channel 35 are disposed in the heat exchanger 30, the fourth heat exchanging channel 34 is communicated with the top of the first gas-liquid separator 41 through a pipeline, and the fifth heat exchanging channel 35 is communicated with the top of the separating tower 50 through a pipeline. The first gas phase escaping from the top of the first gas-liquid separator 41 enters the fourth heat exchange channel 34 to release the cold energy of the first gas phase, so that the cold energy is provided for the synthesis gas to be cooled in the first heat exchange channel 31, and the synthesis gas is exhausted after being reheated; the second gas phase escaping from the top of the separation tower 50 enters the fifth heat exchange channel 35 to release the cold energy of the second gas phase, so that the cold energy is provided for the synthesis gas to be cooled in the first heat exchange channel 31, and the synthesis gas is exhausted after being reheated.

In some embodiments of the present invention, the apparatus for separating and purifying carbon monoxide further comprises a Pressure Swing Adsorption (PSA) device connected to the heat exchanger 30 via a pipeline, the pressure swing adsorption device is connected to the fourth heat exchange channel 34 for separating and purifying the first gas phase, and removing a small amount of carbon monoxide gas from the first gas phase to obtain high-purity hydrogen gas.

The utility model discloses an equipment of separation and purification carbon monoxide makes partly compressed carbon monoxide flow back extremely as backward flow carbon monoxide through set up the return line between carbon monoxide compressor 70 and knockout tower 50 in the knockout tower 50, this part backward flow carbon monoxide can release cold volume after throttling and stepping down, for the synthetic gas cooling provides required cold volume, does not need extra introducing the liquid nitrogen from the equipment outside to supply cold volume, the utility model discloses an equipment not only is applicable to the operating mode that carbon monoxide content is high and pressure is high in the synthetic gas, is applicable to the operating mode that carbon monoxide content is low and pressure is low in the synthetic gas moreover, and application scope is wide.

Based on above-mentioned equipment of separation and purification carbon monoxide, the utility model discloses still provide a method of separation and purification carbon monoxide, adopt the equipment realization of above-mentioned separation and purification carbon monoxide, the method includes:

the synthesis gas enters a first heat exchange channel 31 of the heat exchanger 30 to be cooled, and the synthesis gas is partially condensed into a first gas-liquid mixture;

the first gas-liquid mixture enters the first gas-liquid separator 41 for gas-liquid separation, and a first liquid phase at the bottom of the first gas-liquid separator 41 and a first gas phase above the first liquid phase are formed, and the first gas phase escapes from the top of the first gas-liquid separator 41;

the first liquid phase enters the separation tower 50 and is in countercurrent contact with the ascending gas phase at the bottom of the separation tower 50, and finally a second liquid phase at the bottom of the separation tower and a second gas phase at the top of the separation tower are obtained, and the second gas phase escapes from the top of the separation tower;

after the second liquid phase flows out from the bottom of the separation tower 50, throttling, depressurizing and cooling are carried out through the throttle valve 60 to form a second gas-liquid mixture;

the second gas-liquid mixture enters a third heat exchange channel 33 of the heat exchanger 30 to release cold energy, the second gas-liquid mixture is completely evaporated into carbon monoxide gas, and the carbon monoxide gas enters a carbon monoxide compressor 70 to be compressed;

a part of the compressed carbon monoxide is extracted from the carbon monoxide compressor 70 and enters a return line as return carbon monoxide, and the return carbon monoxide enters the separation tower 50 after being cooled by the third heat exchange channel 33 of the heat exchanger 30.

Specifically, when the pressure of the first liquid phase is relatively high, a throttle valve 60 may be disposed on a pipeline between the first gas-liquid separator 41 and the separation column 50 to reduce the pressure of the first liquid phase, so as to meet the operation pressure requirement inside the separation column 50.

In the embodiment shown in fig. 1, the return line is connected to an inlet of the reboiler 51, an outlet of the reboiler 51 is connected to an upper part or a middle part of the separation column 50 through a line, and the reflux carbon monoxide in the return line firstly enters the reboiler 51 to heat the tower bottom liquid, and flows out of the reboiler 51 and enters the separation column 50 through a line.

In the embodiment shown in fig. 2, the return line is connected to the upper or middle portion of the separation column 50, and the reflux carbon monoxide flows out of the return line and directly into the separation column 50.

The first heat exchange channel 31 comprises a first heat exchange section 311 and a second heat exchange section 312 which are discontinuous, wherein an outlet of the first heat exchange section 311 is communicated to an inlet of the reboiler 51 through a pipeline, an outlet of the reboiler 51 is communicated to an inlet of the second heat exchange section 312 through a pipeline, and an outlet of the second heat exchange section 312 is communicated to the first gas-liquid separator 41 through a pipeline; the synthesis gas firstly enters the first heat exchange section 311 for first cooling, then enters the reboiler 51 via a pipeline to heat the tower bottoms, and then flows out of the reboiler 51 and enters the second heat exchange section 312 via a pipeline for second cooling. After the second cooling, the synthesis gas cooled to a certain temperature (-140 ℃ to-160 ℃) enters a reboiler 51 to provide the required heat for heating the bottom of the tower.

It can be seen that in the embodiments of fig. 1 and fig. 2, the reflux carbon monoxide enters the separation column 50 from the upper part or the middle part of the separation column 50, and during the reflux carbon monoxide flows from the upper part or the middle part of the separation column 50 to the bottom of the column, the reflux carbon monoxide can increase the liquid phase flow rate in the separation column 50, enhance the mass transfer process of the gas-liquid two-phase, enable the carbon monoxide in the second gas phase to be better recovered into the second liquid phase, and enhance the rectification effect.

The utility model discloses a method of separation and purification carbon monoxide flows back to the knockout tower 50 as backward flow carbon monoxide through extracting some compression carbon monoxide, this part backward flow carbon monoxide can provide cold volume for the syngas cooling down after throttling step-down cooling, do not need extra slave unit outside to introduce the liquid nitrogen and supply cold volume, this method is not only applicable to the operating mode that carbon monoxide content is high and pressure is high in the syngas, and be applicable to the operating mode that carbon monoxide content is low and pressure is low in the syngas, compare with traditional carbon monoxide low temperature separation technology, this method's independence is strong, application scope is wide, the flow is simple. Additionally, the utility model discloses after well backward flow carbon monoxide gets into knockout tower 50, can increase the liquid phase flow in knockout tower 50, promote the washing effect, and then improve the rate of recovery of carbon monoxide.

Herein, "upstream" and "downstream" refer to the flow path of the synthesis gas, and in the method for separating and purifying carbon monoxide of the present invention, the synthesis gas flows from upstream to downstream.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims

1. The equipment for separating and purifying the carbon monoxide is characterized by comprising a heat exchanger, a first gas-liquid separator, a separation tower, a second gas-liquid separator and a carbon monoxide compressor which are sequentially communicated through pipelines;

2. The apparatus for separation and purification of carbon monoxide according to claim 1, wherein a reboiler is provided at the bottom of the separation column.

3. The apparatus for separation and purification of carbon monoxide according to claim 2, wherein the return line is connected to an inlet of the reboiler, and an outlet of the reboiler is connected to an upper or middle portion of the separation column through a line.

4. The apparatus for the separation and purification of carbon monoxide according to claim 2, wherein said reflux line is connected to the upper or middle part of said separation column;

5. The apparatus for the separation and purification of carbon monoxide according to claim 1, further comprising a first precooler disposed upstream of and in communication with said heat exchanger via a conduit.

6. The apparatus for separation and purification of carbon monoxide as claimed in claim 1, further comprising a second precooler disposed in said return line between said carbon monoxide compressor and said third heat exchange path of said heat exchanger.

7. The apparatus for purifying and separating carbon monoxide according to claim 1, wherein a plurality of throttle pressure reducing lines are provided between the separation column and the heat exchanger, and each throttle pressure reducing line is provided with a throttle valve.

8. The apparatus for separating and purifying carbon monoxide according to claim 7, wherein a plurality of second heat exchange channels are provided in the heat exchanger, and the plurality of second heat exchange channels are respectively communicated with the plurality of throttling depressurization pipelines.

9. The apparatus for the separation and purification of carbon monoxide according to claim 1, further comprising a purification unit disposed upstream of said heat exchanger.

10. The apparatus for separating and purifying carbon monoxide according to claim 1, wherein a fourth heat exchange channel and a fifth heat exchange channel are arranged in the heat exchanger, the fourth heat exchange channel is communicated with the top of the first gas-liquid separator through a pipeline, and the fifth heat exchange channel is communicated with the top of the separation tower through a pipeline.