POTENTIAL FOR EFFICIENCY ENHANCEMENT OF NEON-HELIUM MIXTURE EXTRACTION IN LOW-PRESSURE ASU

Abstract

Air processed in large air separation units (ASU) is the only source of such valuable gas as neon. In these plants, neon as well as helium accumulates in the upper portion of the main condenser of a lower column. It is noted that the efficiency of neon extraction from air, especially in older designs of ASU, remains low due to its inevitable losses in the apparatus. In modern ASU АКАр-40/35 и КААр-60 losses are 7...11 %. A relatively high degree of extraction of neon in such ASU is achieved due to the use of steam stripping columns instead of dephlegmators (reflux condensers), as well as the use of automatic control systems. It is shown that the control algorithm of ASU should enable extracting such an amount of a neon helium mixture that would bring about maximum values of neon and helium recovery rates.