Distillation method and structured packing

Abstract

A method of conducting a distillation process and a cross-corrugated structured packing for use in such a process in which ascending vapor phases and descending liquid phases are contacted in such packing. The cross-corrugated structured packing contains corrugated sheets fabricated of an open cell foam-like material. The liquid phase produces a liquid film descending along struts forming cells of the material and the vapor phase ascends within the cross-corrugated structured packing and enters the cells and contacts the liquid film. The cross-corrugated structured packing is configured such that a superficial velocity at which ambient air would flow through the cross-corrugated structured packing at a pressure drop of 0.3″ wc/ft is no greater than 20 times a reference superficial velocity at which the ambient air would flow through the foam-like material making up the corrugated sheets at the same pressure drop to ensure that vapor enters the cells of the foam-like material.

1 . A cross-corrugated structured packing comprising:
 a plurality of corrugated sheets having a thickness of between 0.4 mm to 10 mm and fabricated of foam-like material having an open-cell structure formed of a network of interconnected struts defining cells within the open-cell structure;   wherein the foam material has a macro specific area in an area range of between 100 m2/m3 and 500 m2/m3, pores at opposed surfaces of each of the corrugated sheets formed by the cells in at a frequency of between 30 pores per inch and 140 pores per inch, a solids fraction in each of the corrugated sheets in a solids fraction range of between 2 percent and 20 percent; and   the plurality of corrugated sheets configured such that a superficial velocity at which ambient air would flow through the cross-corrugated structured packing at a pressure drop of 0.3″ wc/ft is no greater than 20 times a reference superficial velocity at which the ambient air would flow through the foam-like material making up the corrugated sheets at said pressure drop.   
     
     
         2 . The cross-corrugated structured packing of  claim 1 , wherein the foam-like material is formed of silicon carbide. 
     
     
         3 . The cross-corrugated structured packing of  claim 1 , wherein the superficial velocity is no greater than 15 times the reference superficial velocity. 
     
     
         4 . The cross-corrugated structured packing of clam  1 , wherein the cross-corrugated structured packing has a corrugation angle in each of the corrugated sheets in a corrugation angle range of between 20 degrees and 60 degrees. 
     
     
         5 . The cross-corrugated structured packing of  claim 4 , wherein the cross-corrugated structured packing has a macro specific area in an area range of between 150 m2/m3 and 400 m2/m3, pores formed by the cells in at a frequency of between 40 pores per inch and 100 pores per inch, and the corrugation angle in each of the corrugated sheets, in at least a central region thereof, in the corrugation angle range of between 30 degrees and 50 degrees. 
     
     
         6 . The cross-corrugated structured packing of  claim 5 , wherein the foam-like material is formed of silicon carbide. 
     
     
         7 . The cross-corrugated structured packing of  claim 1 , wherein each of the corrugated sheets is of rectangular configuration and has top and bottom regions of top and bottom corrugations extending from opposed top and bottom edges and connected by central corrugations contained in the central region and oriented at the corrugation angle, the top and bottom corrugations having a corrugation angle of 90 degrees as measured from the top and bottom edges.