Catalytic cracking of hydrocarbons in a riser simulator: The effect of catalyst accessibility and acidity

Different catalysts based on Y-zeolite, ZSM-5, and amorphous kaolin were prepared and characterized. The catalytic cracking of 1,3,5-triisopropylbenzene (1,3,5-TIPB), 1,4-diisopropylbenzene (1,4-DIPB), and n-dodecane were used to investigate the effect of the catalyst nature on the catalytic performance. Cracking the largest molecule (1,3,5-TIPB) using the kaolin, with largest pore structure, was found to be most efficient, although it has lowest acidity. On the contrary, cracking of n-dodecane was found to be very efficient using a catalyst based on ZSM-5 zeolite. Koalin catalyst produces more cumene when used for cracking 1,4-DIPB and 1,3,5-TIPB than the zeolite catalyst. Benzene selectivity was highest for the ZSM-5 catalyst and high reaction temperature. Generally, cracking of 1,3,5-TIPB produces more coke, followed by 1,4-DIPB, and least is n-dodecane. Amorphous kaolin was found to produce less coke than both USY and ZSM-5 zeolites; however, kaolin was found completely inactive in cracking n-dodecane.