Thesis (M.Eng.)--Chulalongkorn University, 1997

Y-type zeolites having the faujasite structure were synthesized in different forms, namely, NaY, NH4Y, and Hy. The preparation parameters studied significantly affected the acquisition of high degree of crystallization of monophasic Y-type zeolites. The optimum preparation conditions were H2O/SiO2 mole ratio of 46.25; pH of gel mixture of 13.7 ; gel preheat temperature of 60 ํC; aging time at room temperature of 16 h; and crystallization conditions of 95 ํC for 48 h. HY catalyst was found to obtain more strong acid site than did NH4Y and NaY, and HY was the most active form for n-octane cracking. The maximum yield per pass (YPP) of the desired products was obtained on HY catalyst at 450 ํC, 2000 h-1, 30 min on stream. The self-prepared HY catalyst exhibited the comparable catalytic performance with that of the corresponding commercial one.