Catalytic Cracking of VGO by Hierarchical Y Zeolite-containing Mesoporous Silica–Alumina Catalysts Using Curie Point Pyrolyzer

Abstract

Hierarchical Y zeolite-containing mesoporous silica _ aluminas were prepared by the one pot sol-gel method using malic acid. Properties for the catalytic cracking of vacuum gas oil (VGO) were estimated using a Curie point pyrolyzer, to establish a novel and very simple estimation method for the catalytic cracking of VGO. Prepared catalysts showed higher conversions and selectivities for gasoline than zeolite single, indicating that yields of gasoline for zeolite-containing catalysts increased compared with that of zeolite single. Higher content of aluminum species in the catalysts resulted in decreased olefin/paraffin ratios and increased iso-/n-ratios (ratio of branched products to straight-chained ones), indicating that hydrogen transfer and isomerization were promoted by the addition of acid sites into the matrix. Catalysts with mesopores tended to form larger amounts of multibranched products, which are very important in modern petroleum refining. When the yields of gasoline, singlebranched products and multi-branched products were plotted against the conversion of VGO, the linear relationships were observed and the effect of kinds of zeolite was rather small, indicating that the activity and the selectivity were largely affected by the presence of matrices. Comparison of the yields of gasoline, single-branched products and multi-branched products at the same conversions showed that Y zeolite-containing catalysts always showed the highest yields and ZSM-5-containing catalysts showed the lowest yields although the differences were small. Pore size of the zeolite probably also affected the yields in the treatment of large molecules such as VGO. The present findings suggest that the appropriate combination of zeolite and matrix is the most important factor to obtain high catalytic activity and high yields of gasoline and branched products.

Catalytic Cracking of VGO by Zeolite–kaolin Mixed Catalysts Using Curie Point Pyrolyzer

“…Therefore, this result may be related to the size of the micropores in the zeolite. Our previous investigation using hierarchical zeolitecontaining catalysts had similar findings 21) . Hydrogen transfer includes two molecular reactions.…”

Catalytic cracking of soybean oil by hierarchical zeolite containing mesoporous silica-aluminas using a Curie point pyrolyzer

“…The zeolites used were ␤ zeolite and HY zeolite (␤ zeolite: SiO 2 /Al 2 O 3 (mol/mol) 37, Na 2 O 0.1 wt%, crystal size 0.05 m, mean particle size (MPS) 5 m, cation type H + , HSZ-940HOA, Tosoh Corp, Tokyo Japan; HY zeolite: JRC-HY5.5, crystal size 0.2 m, MPS 6 m, a reference catalyst in Catalysis Society of Japan (CSJ), prepared by Tosoh Corp.). For comparison, data for the catalytic cracking of hydrotreated VGO (S 100 ppm) were described [31,32]. The properties of the original VGO supplied from Nippon Ketjen Co. Ltd., Tokyo Japan are as follows: V, Ni 0 ppm; S 2.85%; C 85.48%; H 11.60%; Asphaltene 0.18%; IBP 281 -FBP 570 • C; Dens.…”

“…The preparation method of hierarchical composites of zeolitecontaining silica and silica-alumina was described in detail elsewhere [30][31][32]. A typical method follows: TEOS was added to a suspension of zeolite in ethanol and the mixture was stirred for 1 h at 25 • C. Next, an aqueous solution of malic acid was added dropwise, and the mixture was stirred for 30 min.…”

“…We have already reported that mixed catalysts of amorphous mesoporous silica-aluminas and microporous zeolites had higher conversion and product selectivity than simple zeolites or a physical mixture of silica-alumina and zeolite [28][29][30][31][32]. These catalyst systems promoted the formation of branched hydrocarbons, which significantly affect the octane number of gasoline.…”

“…In these studies, a model compound, n-dodecane, was used as a feed material [28][29][30]. Furthermore, a novel method to determine the catalytic cracking of VGO using a Curie point pyrolyzer (CPP) was developed as a very simple method for a catalyst evaluation [31,32].…”