Comparison of protonated zeolites with various dimensionalities for the liquid phase alkylation of i-butane with 2-butene

This study focused on the effects of structure on the catalytic performance of various three-, two-, and one-dimensional zeolites. The alkylation of i sobutane with 2-butene was carried out under both mild and severe condition s with respect to the feed flow rate. It was observed that zeolite beta out performed the other zeolites, exhibiting high olefin conversion and alkylat e selectivity. For the olefin WHSV used in this work, LTL and USY deactivat ed rapidly. It is proposed that their fast deactivation was a result of the periodic expansions of their respective pore structures. In contrast to th e behavior of other zeolites, the C-8 selectivities almost remained high an d constant over LTL. The one-dimensional ZSM-12 was found to outperform in terms of activity many of the samples in this study because of its unique p ore structure. A study of the carbonaceous material formed inside the zeoli tes pores discovered that their composition also depended on the zeolite po re structure. The results of this study indicate that the ability of certai n zeolites to inhibit the formation of coke precursors because of their par ticular pore structures is an important parameter.