Estimation of Catalytic Cracking of Vacuum Gas Oil by a Y Zeolite-Containing Two-Layered Catalyst and a Novel Three-Layered Hierarchical Catalyst Using a Curie Point Pyrolyzer Method

Abstract

A Y zeolite-containing two-layered catalyst and a novel three-layered hierarchical catalyst were prepared using a template and the gel skeletal reinforcement (GSR) method. Initially, two-layered catalysts were prepared by the sol–gel method using malic acid as the template in the presence of HY zeolite (HYZ). The two-layered hierarchical catalyst, 2L­(S-HYZ), consisted of 50 wt % the mesoporous part of silica (S) and 50 wt % the microporous part of HYZ. The three-layered hierarchical catalyst, 3L­(GSR-S)­2L­(S-HYZ), was made by GSR silica (GSR-S) production in the presence of 2L­(S-HYZ) where silica gel particles including 2L­(S-HYZ) inside were reinforced by a reinforcing solution of hexamethyldisiloxane–acetic anhydride before aging and successive calcination and consisted of 50 wt % large-mesoporous GSR-S and 50 wt % the 2L­(S-HYZ) hierarchical catalyst. It was confirmed by XRD and N2 adsorption and desorption measurement that this catalyst possessed three characters of microporous zeolite crystals, small mesoporous silica, and large mesoporous silica. Catalytic cracking of vacuum gas oil over these hierarchical catalysts was performed using a Curie point pyrolyzer method. 3L­(GSR-S)­2L­(S-HYZ)­(Z25), which included 25 wt % HYZ, exhibited the highest activity. Further, it was proposed that the activity could be related to not only the amount of acid sites but also the size of mesoporous pore volume.

Preparation of Two- and Three-layered Hierarchical Catalysts Using Gel Skeletal Reinforcement and Properties for Catalytic Cracking of Low Density Polyethylene

“…Decreases in acid sites were confirmed in the β-zeolite-containing hierarchical catalysts due to the lower zeolite content. 3L-mix-Y catalysts had larger amounts of strong acid sites than other hierarchical catalysts, indicating that the Al species octahedrally coordinated in Y-zeolite combined to acid sites tetrahedrally coordinated in the interface of Y-zeolite crystal and GSR-silica 10) .…”

“…Preparation of Two-and Three-layered Hierarchical Catalysts Using Gel Skeletal Reinforcement and Properties for Catalytic Cracking of Low Density Polyethylene 3L catalysts found better performance than conventional zeolite single or kaolin-mixed catalysts in the catalytic cracking reactions of vacuum gas oil (VGO) 10) and soybean oil (SBO) 28) . We also investigated the catalytic cracking of LDPE using our hierarchical catalysts, and found that 2L catalysts using zeolites and GSR-silica 3) , and another type of 2L hierarchical catalyst using simultaneous generation of zeolite and mesoporous silica 2) , achieved high performances in the catalytic cracking of LDPE.…”

“…Other naming was the same as that of 3L-mix catalysts. Detailed methods to prepare 3L-cogel-Y(Z25) and 3L-mix-Y(Z25) are described elsewhere 10) . Similar methods 3),10) were used to prepare 3L-co-gel-β(Z25) and 3L-mix-β(Z25).…”

“…Various commercially available zeolites (ZSM-5, β, Y and L) have been used in catalytic cracking experiments in our laboratory 1)-3), 10) . The gel skeletal reinforcement (GSR) method and a zeolite-containing hierarchical two-layered (2L) catalyst using malic acid have been developed to provide new types of silica and silica-alumina 1) .…”

Constrained and Open Mesoporosity in Polypropylene Cracking: Insight From Spectroscopic Investigations of Acidity, Diffusion, and Activity

“…The applicability of hierarchical zeolites in reactions involving the cracking of polymers or gas oil is of great interest as the high activity and selectivity of these catalysts are found. − Furthermore, the hierarchical catalysts showed some similarities between the cracking of vacuum gas oil and polymers in the manner of the activity and selectivity . The development of a secondary pore system reflects not only in porosity but also in the acidic picture of modified catalysts .…”