A two-stage series pressure swing adsorption oxygen production system capable of increasing oxygen recovery and its operating method

Abstract

The invention belongs to the technical field of gas separation, and specifically relates to a two-stage series pressure swing adsorption oxygen production system based on an equilibrium adsorption mechanism (that is, an oxygen, nitrogen and argon separation system) capable of improving oxygen recovery and an operating method thereof. In the two-stage series PSA oxygen production system of the present invention, the first-stage PSA is an oxygen-nitrogen separation pressure-swing adsorption separation system based on an equilibrium adsorption mechanism equipped with conventional zeolite and other nitrogen adsorbents, and the second-stage PSA is equipped with an oxygen selector. An oxygen-argon separation pressure swing adsorption separation system based on an equilibrium adsorption mechanism of a neutral nitrogen adsorbent; the present invention is an improvement to the existing two-stage series pressure swing adsorption oxygen production system, that is, a set of mixed feed is set in the second stage PSA The material circuit is operated according to the prescribed working steps, thereby significantly improving the oxygen recovery rate, thus increasing the total oxygen recovery rate.

Description

technical field [0001] The invention belongs to the technical field of gas separation, and specifically relates to a "two-stage series pressure swing adsorption oxygen production system based on an equilibrium adsorption mechanism" (that is, an oxygen, nitrogen and argon separation system) that can improve the oxygen recovery rate and its operating method. Background technique [0002] Pressure swing adsorption (PSA) is an important and widely used gas separation method. The pressure swing adsorption oxygen production method is an important supplement to the cryogenic oxygen production process. The traditional PSA method for producing oxygen from air streams usually uses Nitrogen adsorbents such as CaA, CaX, NaX, and LiX are based on the equilibrium adsorption theory to produce oxygen. Because these adsorbents have a stronger adsorption capacity for nitrogen than oxygen, that is, selectivity, usually a selectivity of more than 3 can achieve a good energy efficiency ratio. Fo...

AI Technical Summary

Problems solved by technology

However, in the various methods adopted, that is, there are at least two different mass transfer zones in the two-stage or multi-stage PSA method, the more typical feature is that at least one of the mass transfer zones uses a carbon dioxide based on the principle of kinetic separation. Molecular sieves are used to separate oxygen and argon. The system cycle is complicated. A large number of buffer tanks and power equipment are used to perform necessary cleaning, replacement or displacement steps to obtain higher oxygen products. The energy consumption is huge and the cost is high.

[0005] Chinese patent CN201930684U discloses a non-cryogenic pressure swing adsorption separation device for oxygen-argon mixed gas. Two identical series adsorption systems based on the equilibrium adsorption mass transfer mechanism are used to construct a separation process, which realizes the separation of oxygen, nitrogen and argon. However, due to insufficient process construction, the oxygen recovery rate of the subsequent oxygen-argon separation system is still limited to less than 50%. 50%, the total oxygen recovery rate of the two-stage pressure swing adsorption system in series is limited to less than 25%, and the application is limited to a certain extent

Images