Design of a core-shell alumina catalyst support: Understanding the elementary mechanisms damaging coating during drying

Unsaturated compounds are produced by conversion processes, e.g., steam cracking or FCC, which invariably produce a mixture of mono and polyunsaturated hydrocarbons that cannot be directly used in petrochemical processes. A support ready for a controlled thickness deposition of metallic palladium particles by dry impregnation of palladium nitrite solution is put forward. The supports were spherical bi-materials whose core is a low specific surface area alumina and the coating is a high specific surface area alumina. A coating process was developed for a pan granulator where the filler is added as a dry powder under a mineral binder pulverization onto α-Al ₂O ₃ beads. The effects of filler particle size and the binder/filler ratio were elucidated. A basis to design core-shell catalyst support with limited segmentation and a higher densification was highlighted. This is an abstract of a paper presented at the 18th International Congress of Chemical and Process Engineering (Prague, Czech Republic 8/24-28/2008).