The deactivation of active sites in liquid-phase alkylation of isobutane with butenes

The deactivation of acid sites of zeolitic catalysts in alkylation of isobutane with butenes was studied. The reactions were lumped into two main reactions; namely, alkylation and the undesired oligomerization reaction which require very strong and moderate acid sites, respectively. Theconversion data of a liquid-phase mixed-flow reactor were analyzed by differential method of analysis to obtain deactivation kinetics. It was found that the activity decline of the individual reactions is the same during useful life of the catalyst, when alkylation is the main reaction, confirming the common approach used for modeling of alkylation reactors, i.e., same types of active sites for different reactions. However, after useful catalyst life, the remaining alkylationsites deactivates much more quickly than oligomerization sites. The deactivation rate constants for alkylation and oligomerization reactions were obtained as 7400 and 6400 lit2/(mol2.h), respectively, at 65°C.

کلیدواژه ها:

isobutane alkylation ، solid acids ، active sites ، catalyst deactivation ، kinetics