Patent ID: 6212907
Filing Date: 2001-04-10
Classification: B01J,F25J,Y10S

Abstract:
A method for operating a cryogenic rectification column comprising:(A) passing a mixture comprising a more volatile component of air and a less volatile component of air into a column, said column containing a height of packing comprising packing sheets which have a bottom portion, a middle portion, and a top portion, with the structure of each packing sheet in the bottom portion being different from the structure of the packing sheet in the middle portion and being the same as the structure of the packing sheet in the top portion;(B) carrying out cryogenic rectification within the column wherein vapor flows upward through the height of packing sheets and liquid flows downward through the height of packing sheets whereby the said more volatile component concentrates in the upflowing vapor and the said less volatile component concentrates in the downflowing liquid;(C) passing the upflowing vapor upward through the height of packing within the column at a flowrate so as to have a pressure drop within the column of at least 0.7 inches of water per foot of packing height; and(D) withdrawing more volatile component from the upper portion of the column and withdrawing less volatile component from the lower portion of the column.