Device for improving carbon dioxide separation effect

Abstract

The utility model relates to a device for improving a carbon dioxide separation effect, and belongs to the technical field of carbon dioxide capture, utilization and storage. The device comprises a subcooler, a rectifying tower, a condenser, a reflux tank and a reboiler, the reboiler comprises a heating pipe and a vaporization space, an inlet of the heating pipe is connected with a feed gas inlet pipe, and an outlet of the heating pipe is connected with a middle pipeline of the side wall of the rectifying tower. According to the utility model, while the equipment structure and the process are simplified, separation is realized by utilizing the boiling point difference of different components, a high-purity product is obtained, the recovery rate of carbon dioxide can reach more than 85%, and meanwhile, the discharged light-component tail gas is recovered for heat exchange and a drying agent regeneration process of a previous procedure, so that the drying agent regeneration process is greatly improved compared with the prior art.

Description

Technical Field

[0001] This utility model belongs to the field of carbon dioxide capture, utilization and storage technology, and specifically relates to a device for improving carbon dioxide separation efficiency. Background Technology

[0002] With increasing global warming and pressure to reduce carbon emissions, carbon dioxide capture, utilization and storage (CCUS) technology has become an important means to achieve dual carbon goals, while the coal chemical industry is one of the main sources of carbon emissions. After desulfurization and drying of the feed gas, it needs to be pressurized and cooled to separate, liquefy and store the carbon dioxide in the feed gas by taking advantage of the different boiling points of the component gases.

[0003] Chinese patent CN111238165B discloses a carbon dioxide distillation device and method based on the utilization of tail gas cold energy. This device reduces energy consumption and increases output by recovering and reusing exhaust gas. However, this device requires multiple distillation columns and reboilers, resulting in a complex structure, cumbersome process, and high production costs. Summary of the Invention

[0004] The purpose of this invention is to provide a device that improves carbon dioxide separation efficiency while simplifying the structure and process and effectively utilizing exhaust gases.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An apparatus for improving carbon dioxide separation efficiency includes a subcooler, a distillation column, a condenser, a reflux tank, and a reboiler. The reboiler includes a heating tube and a vaporization space. The inlet of the heating tube is connected to a feed gas inlet pipe, and the outlet of the heating tube is connected to a pipeline in the middle of the side wall of the distillation column. The bottom and lower part of the side wall of the distillation column are respectively provided with a first liquid phase outlet and a first gas phase inlet. Both the first liquid phase outlet and the first gas phase inlet are connected to the pipeline of the vaporization space. The bottom of the vaporization space is provided with a second liquid phase outlet connected to the pipeline of the subcooler.

[0007] The top of the distillation column is connected to the condenser via piping, the upper part of the side wall of the distillation column is connected to the bottom of the reflux tank via piping, the condenser is connected to the reflux tank via piping, and the top of the reflux tank is connected to a non-condensable gas outlet pipe.

[0008] Furthermore, all of the aforementioned pipelines are equipped with regulating valves.

[0009] Furthermore, the refrigerant in the condenser and the subcooler is liquid ammonia.

[0010] The beneficial effects of this utility model are as follows:

[0011] While simplifying the equipment structure and process, the separation is achieved by utilizing the boiling point differences of different components to obtain high-purity products. The carbon dioxide recovery rate can reach more than 85%. At the same time, the exhaust gas containing light components is recovered for heat exchange and desiccant regeneration in the previous process, which is a significant improvement over existing technologies.

[0012] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a device for improving carbon dioxide separation efficiency according to an embodiment of the present invention.

[0014] Explanation of the symbols in the attached diagram: 1. Subcooler; 2. Distillation column; 3. Condenser; 4. Reflux tank; 5. Reboiler. Detailed Implementation

[0015] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0016] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0018] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0019] See Figure 1 The apparatus for improving carbon dioxide separation efficiency shown in a preferred embodiment of this application includes a subcooler 1, a distillation column 2, a condenser 3, a reflux tank 4, and a reboiler 5. The reboiler 5 includes a heating tube and a vaporization space. The inlet of the heating tube is connected to a feed gas inlet pipe, and the outlet of the heating tube is connected to a pipeline in the middle of the side wall of the distillation column 2. The bottom and lower part of the side wall of the distillation column 2 are respectively provided with a first liquid phase outlet and a first gas phase inlet. The first liquid phase outlet and the first gas phase inlet are both connected to the pipeline of the vaporization space. The bottom of the vaporization space is provided with a second liquid phase outlet connected to the pipeline of the subcooler 1.

[0020] The top of the distillation column 2 is connected to the condenser 3 via a pipeline, and the upper part of the side wall of the distillation column 2 is connected to the bottom of the reflux tank 4 via a pipeline. The condenser 3 is also connected to the reflux tank 4 via a pipeline, and the top of the reflux tank 4 is connected to a non-condensable gas outlet pipe.

[0021] Specifically, regulating valves are installed on all of the above pipelines to control the equipment pressure.

[0022] Specifically, the refrigerant in the aforementioned condenser 3 and subcooler 1 is liquid ammonia, used for efficient cyclic refrigeration.

[0023] Working principle:

[0024] The feed gas, with a pressure of 2.74 MPa and a temperature of 18~30℃, enters the distillation column 2 after passing through the heating tube of the reboiler 5 via the feed gas inlet pipe. The components of the feed gas are cooled to -5~10℃ in the distillation column 2. Due to the different boiling points of the components, light components such as N2, O2, H2, and CO rise in gaseous form, while heavy components such as CO2 and hydrocarbons such as C2, C3, and C4 flow down in liquid form. The heavy components enter the reboiler 5 through the first liquid phase outlet. The light components mixed in the heavy components are vaporized by heating the feed gas and re-enter the distillation column 2 through the first gas phase outlet. The heavy components are cooled to -20~-15℃ by the subcooler 1 and throttled to 2.35 MPa by the regulating valve to obtain the final liquid carbon dioxide product, which is stored in the spherical tank.

[0025] The light component enters the condenser 3 and is cooled to -30~-35℃ before entering the reflux tank 4. The heavy components mixed in the light component are liquefied and refluxed to the distillation column 2. The light component gas flows out and exchanges heat with the feed gas for preliminary cooling before being used as non-condensable gas for the regeneration of the desiccant in the previous process.

[0026] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0027] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An apparatus for improving carbon dioxide separation efficiency, characterized in that, The system includes a subcooler, a distillation column, a condenser, a reflux tank, and a reboiler. The reboiler includes a heating tube and a vaporization space. The inlet of the heating tube is connected to a feed gas inlet pipe, and the outlet of the heating tube is connected to a pipe in the middle of the side wall of the distillation column. The bottom and lower part of the side wall of the distillation column are respectively provided with a first liquid phase outlet and a first gas phase inlet. Both the first liquid phase outlet and the first gas phase inlet are connected to the pipe of the vaporization space. The bottom of the vaporization space is provided with a second liquid phase outlet connected to the pipe of the subcooler. The top of the distillation column is connected to the condenser pipeline, the upper part of the side wall of the distillation column is connected to the bottom pipeline of the reflux tank, the condenser is connected to the reflux tank pipeline, and the top of the reflux tank is connected to a non-condensable gas outlet pipe.

2. The apparatus for improving carbon dioxide separation efficiency as described in claim 1, characterized in that, All of the aforementioned pipelines are equipped with regulating valves.

3. The apparatus for improving carbon dioxide separation efficiency as described in claim 2, characterized in that, The refrigerant used in the condenser and the subcooler is liquid ammonia.

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