necessary for passing vapor therethrough in this respect the tower capacity will be less restricted by eliminating the presence of catalysts in the region of any vapor flow an additional advantage is the ease of loading and unloading the catalyst with the catalyst disposed entirely in an isolated liquid region the containment support may be more accessible and servicing of this region of the tower will be simplified in comparison to installation or removal of catalyst confined within a packing structure or attached to a trayed device referring now to fig3 and 5 in combination three diagrammatic schematics are presented of alternative means of applying liquid phase reaction with select liquid only reaction zones 99 in conjunction with mass transfer in accordance with the principles of the present invention these three illustrations show the location of the liquid only reaction zones 99 in select regions of a process tower 12 in accordance with the principles of the present invention in fig3 for example the tower 12 is constructed in a manner similar to that shown in fig2 wherein the reaction zone 99 is disposed entirely in the lower region 100 of the tower 12 the bottom stream takeoff line 30 is diagrammatically illustrated in.