Improved HETP is obtained in the operation of a distillation column containing trays with a packing of a porous container containing a particulate material intimately associated with a resilient component having at least 50 volume % open space, preferably at least 70 volume % positioned on the trays compared to the trays without the packing. The packing may contain a catalytic particulate material and the distillation may involve reaction and distillation of the reaction products. The particulate material may also be inert and the distillation of the conventional type to separate components in the distillation mixture without reaction.