um ▁pressure ▁swing ▁ad s or ption ▁( V PS A ) ▁are ▁commer cially ▁used ▁to ▁separate ▁a ▁single ▁component ▁from ▁ordinary ▁air . ▁High ▁pur ity ▁o xygen , ▁nit ro gen , ▁and ▁arg on , ▁used ▁for ▁sem icon duct or ▁device ▁fabric ation , ▁require ▁cry ogen ic ▁dist ill ation . ▁Similarly , ▁the ▁only ▁vi able ▁source ▁of ▁the ▁rare ▁g ases ▁ne on , ▁k rypt on , ▁and ▁x en on ▁is ▁the ▁dist ill ation ▁of ▁air ▁using ▁at ▁least ▁two ▁dist ill ation ▁columns . ▁ ▁Cry ogen ic ▁dist ill ation ▁process ▁ ▁P ure ▁g ases ▁can ▁be ▁separated ▁from ▁air ▁by ▁first ▁cool ing ▁it ▁until ▁it ▁li que f ies , ▁then ▁select ively ▁dist illing ▁the ▁components ▁at ▁their ▁various ▁bo iling ▁temper atures . ▁The ▁process ▁can ▁produce ▁high ▁pur ity ▁g ases ▁but ▁is ▁energy - int ensive . ▁This ▁process ▁was ▁pione ered ▁by ▁Carl ▁von ▁Lin de ▁in ▁the ▁early ▁ 2 0 th ▁century ▁and ▁is ▁still ▁used ▁today ▁to ▁produce ▁high ▁pur ity ▁g ases . ▁He ▁developed ▁it ▁in ▁the ▁year ▁ 1 8 9 5 ; ▁the ▁process ▁remained ▁purely ▁academic ▁for ▁seven ▁years ▁before ▁it ▁was ▁used ▁in ▁industrial ▁applications ▁for ▁the ▁first ▁time ▁( 1 9 0 2 ). ▁ ▁The ▁cry ogen ic ▁separation ▁process ▁requires ▁a ▁very ▁tight ▁integration ▁of ▁heat ▁ex ch angers ▁and ▁separation ▁columns ▁to ▁obtain ▁a ▁good ▁efficiency ▁and ▁all ▁the