The selective transformation of toluene to produce a C2+ n-alkanes-rich stream has been studied over Pt/HZSM-5. The bifuncional catalyst was made mixing physically a Pt/Al2O3 metallic function with various HZSM-5 zeolites varying Al concentration (Si:Al = 15, 25, 40, 140 and a steamed zeolite). The experiments have been conducted in a fixed bed reactor under hydrocracking conditions, i.e. 250-450°C, 2-6 MPa, with H 2/Toluene molar ratio between 20 and 49. The displayed results indicate a significant effect in toluene conversion and the C2+ n-alkanes selectivity of the total acidity of the zeolite. Moreover, the increase of the acidity diminishes the requirements of temperature and hydrogen partial pressure, while simultaneously increases the undesired methane selectivity (improved by strong acid sites) which in turn can limit the total acidity of the zeolite. On the other hand, the maximum yield of high valuable isoalkanes (gasoline pool) is reached with a medium-acidity zeolite.
|Original language||English (US)|
|Title of host publication||CHISA 2006 - 17th International Congress of Chemical and Process Engineering|
|State||Published - Dec 1 2006|