microns preferably 1 to 100 microns and typically 1 to 20 microns in certain instances it may be desirable to use aluminas with a median particle size of 1 to 10 microns the alumina may be ground to the desired particle size before or after activation the activated alumina typically has an loi loss on ignition in the range of about 5 to 12 at a temperature of 200 u00b0 to 1000 u00b0 c one source of activated alumina is gibbsite which is one form of alumina hydrate derived from bauxite using the bayer process however alpha alumina monohydrate pseudoboehmite or the alumina trihydrate may be used if sufficiently calcined other sources of alumina may also be utilized including clays and alumina alkoxides another necessary component of the present invention is a zeolite zeolites are crystalline aluminosilicate compositions which are microporous and which have a three dimensional oxide framework formed from corner sharing alo 2 and sio 2 tetrahedra zeolites are characterized by having pore openings of uniform dimensions having a significant ion exchange capacity and being capable of reversibly desorbing an adsorbed phase which is dispersed throughout the internal voids of the crystal without significantly displacing any atoms which make up the permanent zeolite crystal structure the zeolites which can be used in.