engleski

Effect of Catalyst Preparation on Ni-Al2O3 Poisoning by Thiophene

The influence of experimental conditions such as thetemperature of calcination and pelleting pressure on Ni-Al2O3deactivation by thiophene in benzene hydrogenation is outlinedand discussed. It was found that benzene hydrogenation over unpoisonednickel catalyst is a structure-insensitive reaction. However, itsinhibition by thiophene produced structure sensitivity: thereaction rate was less sensitive to thiophene for large nickelcrystallites (formed during catalyst calcination at hightemperatures followed by reduction), than for small crystallites.Thus the structure sensitivity of poison adsorption imparted anapparent structure sensitivity to the main reaction in thepresence of a poison in the feedstream (secondary structuresensitivity). The pore structure of the catalyst pellet directly influencesthe degree of diffusion resistance of both the main and thepoisoning reactions. It was found that higher mass transferresistances increase the life-time of the pellets while a lowermass transfer resistance increases the overall effectivenesfactor.

Catalyst Preparation; Thioresistance; Temperature of Calcination; Pelleting Pressure

nije evidentirano