valve 320 and as stream 25 into higher pressure column 260 and into a second condensed feed air stream 28 which is passed through valve 340 and as stream 30 into lower pressure column 280 feed air stream 8 is further compressed by passage through compressor 120 and resulting feed air stream 10 is cooled by indirect heat exchange with return streams in main heat exchanger 200 to form third feed air stream 12 third feed air stream 12 is turboexpanded by passage through turboexpander 220 to generate refrigeration bearing third feed air stream 14 having a temperature generally within the range of from 99k to 117k the temperature of condensed feed air stream 24 does not exceed the temperature of turboexpanded third feed air stream 14 turboexpanded third feed air stream 14 is passed into the lower portion of higher pressure column 260 within higher pressure column 260 the feed air is separated by cryogenic rectification in nitrogen enriched vapor and oxygen enriched liquid nitrogen enriched vapor is withdrawn from the upper portion of higher pressure column 260 as stream 50 having a temperature generally within the range of from 94k to 96k preferably the temperature of the condensed feed air stream 24 which is ultimately passed into the higher pressure column exceeds the temperature of the nitrogen enriched vapor in stream 50 withdrawn from the higher pressure column a portion 54 of stream 50 may be warmed in main heat exchanger 200 and recovered as higher pressure nitrogen product 90 the remaining portion 52 of the withdrawn nitrogen enriched vapor is condensed by indirect heat.