Preparation of an active and regenerable catalyst for liquid-phase alkylation of toluene with 1-decene

Abstract

Zeolite Y was tested as an alternative solid acid catalyst for the production of linear alkyl aromatics with the emphasis on its activity and stability towards regeneration. Liquid-phase alkylation of toluene with 1-decene at 100°C was used as the model reaction. Deactivated catalyst samples were regenerated by the temperature programmed calcination (TPC) in air flow at 550°C. The activity of the unmodified HY zeolite during alkylation was significant but decreased to a minimum after regeneration, as a result of a partial structure collapse during regeneration using TPC. To avoid the structure collapse hydrothermal stabilization of zeolite Y at 560, 670 and 780°C was performed. Subsequent chemical dealumination using 0.5M HCl or ion-exchange with the 2M NH4NO3 solution, in order to improve the catalyst activity, were carried out. All the samples were then tested in alkylation. The main monitored parameters were the conversion of 1-decene, selectivity to 2-phenyldecane isomer and the amount of side-products. The sample stabilized at 560°C and ion-exchanged subsequently showed the highest activity with the lowest amount of by-products. This sample was also regenerated and reused four times in the cycle alkylation–regeneration with no loss of structure or activity. In fact there was a slight activity increase of this sample after regeneration.