Multiple reboiler, double column, air boosted, elevated pressure air separation cycle and its integration with gas turbines.

摘要

The present invention is a liquid nitrogen reflux means improvement capable of allowing the operation of conventional dual and triple reboiler air separation cycles at elevated pressures. The improvement comprises: (a) further compressing and cooling a portion (126) of the compressed, essentially impurities free, feed air (100) to a first column (110), thereby producing a further compressed second portion (170); (b) removing and increasing the pressure of a portion of the liquid oxygen bottoms (160) of the second column (116) and heat exchanging (148) the increased pressure liquid oxygen bottoms against at least a portion of said further compressed second portion (170) so that upon heat exchange the portion of said further compressed second portion (170) is at least partially condensed and the increased pressure liquid oxygen bottoms portion is at least partially vaporized; (c) feeding the at least partially condensed portion (172) of step (b) to at least one of the two distillation columns (110,115); (d) warming (104) the at least partially vaporized oxygen (164) of step (b) to recover refrigeration; (e) compressing (212) a portion of the gaseous nitrogen product (152) and cooling it to a temperature near its condensation temperature by heat exchange (104) against warming process streams; and (f) condensing (136) the cooled, compressed gaseous nitrogen product portion (214) of step (e) and feeding the condensed nitrogen portion (138,140) as reflux to at least one of the distillation columns (110,116).