RETAINED AND DESORBED PRODUCTS FROM REACTION OF 1-OCTENE OVER H-ZSM-5 ZEOLITE

Retained products have been studied from the reaction of 1-octene over H-ZSM-5 zeolite at 393-593 K. Except for the much enhanced proportion of retained alkylbenzenes from 1-octene at over 453 K, the residue from 1-octene had a composition/temperature profile generally similar to that using 1-hexene (alkanes at 393 K decreasing rapidly at higher temperatures; alkylcyclopentadienes at intermediate and higher temperatures; alkylnaphthalenes at 593 K). It is concluded that the route to higher aromatics via alkylcyclopentadienes operates with 1-octene in a similar manner to that previously established for 1-hexene. However, the relatively large proportion of retained alkylbenzenes from 1-octene at over 453 K is attributed to direct dehydrogenative reactant cyclization, a route that is difficult with 1-hexene. Side-chain cyclization in suitable alkylbenzenes can thus provide a route to alkylindenes/indanes and to alkylnaphthalenes which is more significant with 1-octene reactant than with 1-hexene.