Preparation of nanozeolite-based RFCC catalysts and evaluation of their catalytic performance in RFCC process

摘要

The NaY zeolites with different particle sizes of about 20-30 nm and 1-2 mu m were synthesized by hydrothermal routes and characterized by XRD, FT-IR, BET and SEM techniques. The XRD analyses demonstrated the formation of NaY zeolites with high crystallinity and the BET analyses showed that the nanozeolite possessed a higher external surface area (102 m(2)/g) than microzeolite (11 m(2)/g). In order to evaluate the effect of zeolite particle size and zeolite content on the catalytic performance of the residue fluid catalytic cracking (RFCC) catalyst, nanozeolite-based and microzeolite-based catalysts were prepared using silica as inactive matrix. It is clearly demonstrated that the acidity improves with the reduction of zeolite particle size. On the other hand, in equal zeolite content (30 wt%), the nanozeolite-based catalyst possessed higher acidity (2.30 mmol NH3/g catalyst) than microzeolite-based catalyst (1.53 mmol NH3/g catalyst). The microactivity tests (MAT) demonstrated that in equal zeolite content the nanozeolitebased catalysts showed higher catalytic performance than microzeolite-based catalysts. Moreover, the nanozeolite-based catalyst with 30 wt% zeolite (NC30) and a BET area of 346 m(2)/g showed the optimum catalytic performance in RFCC process, with the highest gasoline yield (32 wt%) and gasoline selectivity (56 wt%). (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.