FCC catalysts containing the high-silica faujasites EMO and EMT for gas-oil cracking

High-silica (Si/Al = 4) cubic (EMO) and hexagonal (EMT) faujasites have been thermally and hydrothermally modified and formulated into a number of FCC catalysts for gas-oil cracking. In general, no differences in MAT selectivities are observed for EMO compared with conventional zeolite Y reference catalysts; however, there is some improvement in bottoms cracking for EMT-based catalysts. The exceptional improvement in zeolite stability found on ultrastabilising these high-silica faujasites translates into activity only at high rare-earth loadings. At lower rare-earth contents catalyst activity and, more especially, activity per steamed surface area were much lower for EMO and EMT than for conventional zeolite Y. (C) 1999 Elsevier Science B.V. All rights reserved.