There are three kinds of air separation technology: adsorption method, membrane separation method and low temperature method.
Adsorption method: the final separation purpose is achieved by using the selective adsorption performance of molecular sieve for different molecules. The technical process is simple, the operation is convenient, and the operation cost is low. However, it is difficult to obtain high-purity products, and the capacity of the device is limited, so the technology has its limited application scope.
Membrane separation method: the membrane permeation technology is used to realize the coarse separation of two components by using the different rate of oxygen and nitrogen passing through the membrane. This method is more simple, easy to operate and small investment, but the product can only reach 28% – 35% oxygen enriched air, and the scale is only suitable for small and medium-sized, which is only suitable for oxygen enriched combustion and health care applications.
Low temperature method: using the different boiling points of each component in the air, through a series of technological processes, liquefy the air and separate different components by distillation. Compared with the former two methods, this method can realize the complete separation of air components, product purification, large-scale plant and dual state (liquid and gas), so it plays a leading role in the industrialization of production equipment. Compared with the traditional separation, the separation of these gases can only be realized in the low temperature environment below 100k, so it is called cryogenic method (or cryogenic method).
Low temperature air separation technology is widely used in industry.
Post time: Nov-02-2020