Large-scale air separation systems: Cryogenic, PSA and membrane methods

Applications for oxygen and other products of air separation have increased significantly and have led to the installation of still larger scale air separation plants to supply user-processes by pipeline. Such plants have single stream capacities of 3,000 to 4,000 tonnes per day oxygen, often with co-product nitrogen and argon. The largest tonnage capacities are based on cryogenic, low temperature separation techniques and their applications and features, together with those of modem plants using pressure-swing adsorption, and membrane systems, are covered. The economic break-even points of the these latter methods compared to cryogenic plants are mentioned.