EFFECT OF RELATIVE CRYSTALLINITY AND Na_2O CONTENT IN ZEOLITE-BETA ON CATALYTIC PERFORMANCE OF FLUID CATALYTIC CRACKING CATALYST

The relative crystallinity and Na\-2O content in zeolite beta introduced into fluid catalytic cracking (FCC) catalyst have some effect on its catalytic performance. It was found that the key affecting factor on catalysis of FCC catalyst was the relative crystallinity of zeolite\|beta after the catalyst was hydrothermally treated using 100% water vapor at 780 ℃ for four hours, while Na\-2O content in zeolite beta had no remarkable effect on its catalysis. On the contrary, after the catalyst was hydrothermally treated at 780 ℃ for seventeen hours, Na\-2O content of zeolite beta had a great effect on the stabilization of zeolite skeleton. High contention of Na\-2O in zeolite beta can lead to catalysis of FCC catalyst decreasing as contrasting to low content of Na\-2O in zeolite beta introduced into FCC catalyst, and the yields of low carbon olefins and isomeric paraffins also decreased. The relative crystallinity of zeolite beta introduced into FCC catalyst should be over 80 percent, and Na\-2O content may be less 0.1 percent.