Gas separation method using sub-pressure swing adsorption

Abstract

The invention discloses a gas separation method using sub-pressure swing adsorption, wherein the method comprises pretreatment, negative pressure adsorption concentration, refinement, and recovery removal. According to the present invention, based on pressure swing adsorption, different material components have different adsorption separation coefficients and different physicochemical properties under a negative pressure, adsorption is performed under the negative pressure, evacuation or rinsing desorption is performed, and various separation methods are coupled, such that various mixed gasesare separated and purified through the circulation operation of the pressure swing adsorption process, and particularly the relatively easily adsorbed (and relatively difficultly desorbed) component is separated and purified, wherein the adsorption and the desorption in the circulation are easily matched and balanced; the generated non-adsorbed gas is the intermediate gas, or is the product gas and the qualified discharge gas, or enters the subsequent refining process so as to be refined to obtain the product gas or the qualified discharge gas; and the generated desorbed gas is the condensed gas, and sequentially enters the subsequent recovery removal process so as to further recover or remove the adsorbate component.

Description

technical field [0001] The invention relates to the technical field of gas separation, in particular to a gas separation method of negative pressure swing adsorption. Background technique [0002] Gas separation is widely used in various industries such as petrochemical, coal chemical, biomedicine, fine chemical, electronics, power generation, coal, food, daily necessities, etc., especially in atmospheric environmental protection, comprehensive treatment of industrial waste gas, and energy saving and emission reduction in industrial production. Gas separation has become the most important technical method and means. Gas separation generally needs to remove some impurity components from the mixed raw material gas containing multiple components, and the content of these impurity components (concentration, all by volume %, similar to the following) is less than 1~10%, the separation process It is called purification, that is, removal; the rest of the separation process is call...

AI Technical Summary

Problems solved by technology

Adsorption is often carried out in a pressure environment. Pressure swing adsorption proposes a method of combining pressure and decompression. At a certain temperature, it is usually an adsorption-desorption (regeneration) composed of pressure adsorption and decompression regeneration. Circulation operating system; pressure swing adsorption PSA method Although the product has high purity, simple equipment, low energy consumption of the device, and easy automatic operation, the traditional PSA also has some significant shortcomings: the product yield is low; the contradiction between adsorption and desorption cannot be resolved , which limits the application in many occasions, such as desorption and purification of trace impurities, adsorption and recovery of components with lower partial pressure, etc.; it is difficult to adsorb weakly polar impurities, and it is difficult to desorb and regenerate highly polar trace impurities, etc.

General adsorption separation methods can be properly coupled with traditional energy-consuming separation methods such as rectification and absorption to solve some common limitations and shortcomings of traditional separation methods such as high energy consumption and low purity.

However, most of this coupling process is still adjusted or matched on the basis of traditional PSA or TSA, which fundamentally cannot solve many problems of traditional separation methods, and at the same time cannot make full use of the unique energy of the raw material gas. Or it is impossible to expand the application fields of general pressure swing adsorption or temperature swing adsorption or temperature swing pressure swing adsorption

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