Carbon dioxide liquefaction refining system

Abstract

The utility model discloses a carbon dioxide liquefaction refining system. High pressure and low temperature need to be achieved in a pure compression-cooling mode, the requirement for equipment is high, and energy consumption is large. The device comprises an adsorption purification tower, a filter, a first carbon dioxide refrigerator and a second carbon dioxide refrigerator, a carbon dioxide pipeline from the filter of the drying tower is divided into two paths, one path is communicated with the first carbon dioxide refrigerator, and the other path is communicated with the adsorption purification tower; an outlet of the adsorption purification tower is communicated with an inlet of the filter through a pipeline, an outlet of the filter is communicated with an inlet of the reboiler through a pipeline, and an outlet of the reboiler is communicated with an inlet of the second carbon dioxide refrigerator through a pipeline. An outlet of the second carbon dioxide refrigerator is communicated with an inlet in the middle of the purifying tower through a pipeline, and a tower kettle of the purifying tower is communicated with the subcooler through a pipeline. The device is used for liquefying and refining carbon dioxide.

Description

Technical Field

[0001] This utility model relates to a carbon dioxide liquefaction and refining system. Background Technology

[0002] Carbon dioxide is a widely distributed gas in nature, produced in large quantities during industrial production and energy utilization. It has characteristics such as a low critical temperature (approximately 31.1℃) and a high critical pressure (approximately 7.38MPa). While it typically exists in a gaseous state at room temperature and pressure, it can be liquefied through pressurization and cooling. This liquefaction property makes carbon dioxide valuable in many fields, such as refrigeration, chemical engineering, and food processing.

[0003] In the past, compression-cooling methods were commonly used for the liquefaction of general gases. However, for gases like carbon dioxide with specific critical parameters, traditional liquefaction technologies have some limitations. For example, simple compression-cooling requires achieving high pressure and low temperature, which places high demands on equipment and consumes a lot of energy. Moreover, during the liquefaction process, problems such as impurity contamination and low liquefaction efficiency can easily occur, affecting subsequent refining processes.

[0004] With increasing environmental awareness and restrictions on greenhouse gas emissions, the recovery and utilization of carbon dioxide has received growing attention. Liquefying and refining carbon dioxide makes it easier to store and transport, facilitating its application in subsequent chemical synthesis, food preservation, and other fields. Simultaneously, refining removes impurities such as moisture, oxygen, and hydrocarbons, increasing the purity of carbon dioxide and meeting the quality requirements of various applications.

[0005] To meet the demand for high-purity, high-quality carbon dioxide in industrial production and gas applications, we can invent a carbon dioxide liquefaction and refining system to produce qualified carbon dioxide. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a carbon dioxide liquefaction and refining system.

[0007] The above objectives are achieved through the following technical solutions:

[0008] A carbon dioxide liquefaction and purification system comprises: an adsorption purification tower, a filter, a first carbon dioxide refrigerator, and a second carbon dioxide refrigerator. A carbon dioxide pipeline from the filter in the drying tower is divided into two branches, one connected to the first carbon dioxide refrigerator and the other connected to the adsorption purification tower. The outlet of the adsorption purification tower is connected to the inlet of the filter via a pipeline. The outlet of the filter is connected to the inlet of a reboiler via a pipeline. The outlet of the reboiler is connected to the inlet of the second carbon dioxide refrigerator via a pipeline. The outlet of the second carbon dioxide refrigerator is connected to the inlet of the middle section of the purification tower via a pipeline. The bottom of the purification tower is connected to a subcooler via a pipeline.

[0009] In the aforementioned carbon dioxide liquefaction and refining system, both the first and second carbon dioxide refrigeration units are screw chiller units. Beneficial effects

[0010] 1. This utility model can produce qualified carbon dioxide through a simple and effective carbon dioxide liquefaction and refining system. It is equipped with two liquefaction units, one of which is an industrial carbon dioxide liquefaction unit, which converts carbon dioxide into liquid carbon dioxide through compression and refrigeration for storage, and the other is a food-grade carbon dioxide liquefaction unit, which prepares food-grade carbon dioxide liquid through purification, filtration, reboiling, refrigeration, purification and subcooling to meet the needs of different application scenarios. Attached Figure Description

[0011] Appendix Figure 1 This is a schematic diagram of the present invention;

[0012] In the diagram: 1. Adsorption purification tower; 2. Filter; 3. First carbon dioxide refrigerator; 4. Second carbon dioxide refrigerator; 5. Reboiler; 6. Purification tower; 7. Subcooler. Detailed Implementation

[0013] Reference Figure 1 A carbon dioxide liquefaction and purification system comprises: an adsorption purification tower 1, a filter 2, a first carbon dioxide refrigerator 3, and a second carbon dioxide refrigerator 4. A carbon dioxide pipeline from the filter in the drying tower is divided into two paths: one path connects to the first carbon dioxide refrigerator, and the other path connects to the adsorption purification tower. The outlet of the adsorption purification tower is connected to the inlet of the filter via a pipeline. The outlet of the filter is connected to the inlet of a reboiler 5 via a pipeline. The outlet of the reboiler is connected to the inlet of the second carbon dioxide refrigerator via a pipeline. The outlet of the second carbon dioxide refrigerator is connected to the inlet in the middle of a purification tower 6 via a pipeline. The bottom of the purification tower is connected to a subcooler 7 via a pipeline. Both the first and second carbon dioxide refrigerators are screw compressor units.

[0014] This system consists of two liquefaction units. It uses compression and evaporation refrigeration to liquefy carbon dioxide gas into a liquid at -20℃ and 2.2MPa. It uses a screw refrigeration unit to liquefy carbon dioxide into a liquid at -20℃, which meets the requirements for storage and transportation.

[0015] Food-grade CO2 must meet the requirements of GB 1886.228-2016 "Food Additives - Carbon Dioxide," with a purity of 99.99% or higher, which requires distillation. The raw carbon dioxide gas mainly consists of CO2, N2, O2, SOx, and NOx impurities. The purpose of refining, purifying, and liquefying carbon dioxide is to remove all components except CO2 from the raw gas, thereby obtaining high-purity liquid CO2. Through a purification tower, the CO2 purity is increased to food-grade ≥99.99%, meeting the needs of different application scenarios. The refining system employs advanced separation technology, optimizes the purification process, reduces equipment investment and operating costs, and ensures product quality. For a single CO2 component, only a phase change occurs, but the trace impurities in the raw CO2 must be refined and purified.

[0016] The carbon dioxide from the drying tower filter is divided into two streams. One stream enters the first carbon dioxide refrigeration unit for compression and cooling, forming liquid carbon dioxide which is then stored in an industrial-grade spherical tank. The other stream of carbon dioxide first enters the adsorption purification tower for purification, then enters the filter for filtration, and after filtration, it enters the reboiler 5, where part of the carbon dioxide in the tower bottom is vaporized while the reboiler cools itself. Then, it enters the second carbon dioxide refrigeration unit for liquefaction. After liquefaction, it enters the middle of the carbon dioxide purification tower, where it undergoes mass and heat transfer with the rising steam in the packing material. The high-purity liquid carbon dioxide enters the tower bottom, and then is cooled by the cooler 7 before being stored in the spherical tank.

Claims

1. A carbon dioxide liquefaction and purification system, characterized in that: Its components include: an adsorption purification tower, a filter, a first carbon dioxide refrigerator, and a second carbon dioxide refrigerator. The carbon dioxide pipeline from the filter in the drying tower is divided into two paths, one of which connects to the first carbon dioxide refrigerator and the other connects to the adsorption purification tower. The outlet of the adsorption purification tower is connected to the inlet of the filter through a pipeline. The outlet of the filter is connected to the inlet of the reboiler through a pipeline. The outlet of the reboiler is connected to the inlet of the second carbon dioxide refrigerator through a pipeline. The outlet of the second carbon dioxide refrigerator is connected to the inlet in the middle of the purification tower through a pipeline. The bottom of the purification tower is connected to the subcooler through a pipeline.

2. The carbon dioxide liquefaction and refining system according to claim 1, characterized in that: Both the first and second carbon dioxide refrigeration units are screw refrigeration units.

Images