Hierarchical
ZSM‑5 Materials for an Enhanced
Formation of Gasoline-Range Hydrocarbons and Light Olefins in Catalytic
Cracking of Triglyceride-Rich Biomass
- Publication date
- Publisher
Abstract
A hierarchical ZSM-5 material with
a high fraction of mesoporosity
coupled to well-preserved intrinsic zeolite characteristics has been
successfully prepared by postsynthesis modifications involving optimization
of base treatment and subsequent strong acid washing of commercial
Al-rich ZSM-5 (parent ZSM-5). The resulting hierarchical ZSM-5 material
was thoroughly characterized before being tested in the cracking of
triglyceride-rich biomass, i.e., model feedstock triolein and real
feedstock waste cooking oil under fluid catalytic cracking conditions.
The results show that the introduction of intracrystalline mesoporosity
enhances the utilization of zeolite acid sites by the enlarged external
surface, leading to an increased conversion. At the same time, it
partially suppresses the undesired secondary reactions by shortening
micropore diffusion path lengths. With such a hierarchical ZSM-5 material,
higher selectivities toward the desired products, i.e., gasoline-range
hydrocarbons and light olefins, than with commercial ZSM-5 have been
achieved