Patent ID: 6351971
Filing Date: 2002-03-05
Classification: B01D,F25J,Y10S

Abstract:
A process for producing high purity argon product, the process comprising:(a) providing a feed air stream to a cryogenic separation unit; (b) passing a crude argon feed stream from a lower pressure column of the cryogenic separation unit to a low ratio argon column; (c) passing crude argon overhead from the low ratio argon column to a crude argon condenser to produce crude argon condensate; (d) passing crude argon, from one of the overhead of low ratio argon column or the crude argon condensate of the crude argon condenser, to a vacuum pressure swing adsorption (VPSA) system as crude pressurized argon fluid, and adsorbing oxygen from the crude pressurized argon fluid to produce an argon enriched stream and a residual stream; (e) passing the enriched argon stream from the VPSA to a reboiler in a high ratio column; (f) liquefying the enriched argon stream from the VPSA system in the reboiler and transferring the liquefied enriched argon stream to an intermediate level of the high ratio column; (g) passing overhead vapor from the high ratio column to a high ratio argon condenser and recycling vapor from the high ratio argon condenser to the lower pressure column of the cryogenic separation unit; (h) liquefying argon in the high ratio condenser and returning liquefied argon from the high ratio condenser to the top of the high ratio column as reflux; and (i) removing nitrogen in the high ratio column and recovering high purity argon fluid from the bottom of the high ratio column as high purity argon product.