Novel carbon dioxide trapping device performing liquefaction and then sublimation

Abstract

The invention discloses a novel carbon dioxide trapping device performing liquefaction and then sublimation. According to the device, research on physical properties of carbon dioxide and related mixtures is combined, and gas-liquid separation is performed firstly through a low temperature mode to obtain a part of liquid carbon dioxide; mixed gas after the liquefaction separating is cooled continuously and passes through two sublimation separating towers, and then carbon dioxide is separated; and dry ice obtained from sublimation separation is collected into a condensation pool, and the pressure is controlled above triple point pressure of carbon dioxide, so that the obtained dry ice can be melted directly into liquid carbon dioxide. The overall system design facilitates sufficient cold quantity recovery. The device improves the carbon dioxide trapping purity effectively, increases the carbon dioxide trapping efficiency, improves the cold quantity recovery rate of the system, and is energy-saving and low in consumption.

Description

technical field [0001] The invention separates carbon dioxide from raw material gas rich in carbon dioxide through compression and cooling, and belongs to the technical field of refrigeration and low temperature. Background technique [0002] While the rapid industrial development process brings people convenient life, it also brings huge environmental problems to people. According to the statistics of the US Department of Energy, the annual emission of carbon dioxide due to the burning of fossil fuels reaches more than 30 billion tons, and it is still growing . Heavy industries such as power plants burning fossil fuels, oil plants, and steel plants are the main sources of carbon dioxide emissions. The volume content of carbon dioxide in the flue gas emitted by power plants is about 15%, and the volume content of carbon dioxide in the flue gas emitted by some metallurgical plants is higher than that of power plants. About 35%. In addition to the large amount of carbon diox...

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Problems solved by technology

The solution absorption method has mature technology and is widely used, but this method requires a lot of heat in the regeneration stage, which leads to high energy consumption. The preparation of absorbent requires a lot of energy and the absorbent is corrosive and toxic. At the same time, the absorbent is repeatedly absorbed and regenerated. It will fail during the process and needs to be continuously replenished; the pressure swing adsorption method has no corrosive medium and low operation and maintenance costs, but in order to obtain higher carbon dioxide purity, more adsorption towers are needed, equipment management is more difficult, and the investment is relatively high; Membrane separation The process of this method is simple and easy to operate, but it has high requirements for raw material gas, the processing capacity is small at this stage, the membrane making process is complicated, and the membrane stability is poor.

The above commonly used methods still have a common problem, that is, the separated carbon dioxide products are all gases, which require energy consumption to be further processed into liquids for transportation and storage.

In addition, the purity of the separated and captured carbon dioxide products is generally difficult to meet the specifications for direct application. If the captured carbon dioxide needs to be applied to various industries, further purification is required

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