Diffusion of Heavy Oil in SiO2 Model Catalyst and FCC Catalyst

Zi Yuan Liu; Sheng Li Chen; Peng Dong; Xiu Jun Ge

doi:10.4028/www.scientific.net/AMR.550-553.158

Paper Titles

Synthesis of Ethylene Carbonate from Urea and Ethylene Glycol over La(NO₃)₃ Catalyst
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Study on Catalytic Decomposition of N₂O over Modified Zeolites
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Synthesis and Photocatalytic Mechanism of Visible Light-Activated LaVO₄/TiO₂ Composite
p.149

Study on a New High-Efficiency Treatment Method of Printing and Dyeing Wastewater
p.153

Diffusion of Heavy Oil in SiO₂ Model Catalyst and FCC Catalyst
p.158

Preparation of Isoamyl Acetate by Reaction-Distillation Using Ionic Liquid as Catalyst
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Clean Oxidation of Cyclohexanone to Adipic Acid Catalyzed by Ammonium Phosphomolybdate with Dawson Structure under Microwave Irradiation
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Ethanol Synthesis from Dimethyl Oxalate Hydrogenation on Cu/SiO₂ Catalyst
p.175

Oxidation of α-Pinene with Hydrogen Peroxide Catalyzed by VO(OAc)₂
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HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 550-553Diffusion of Heavy Oil in SiO2 Model Catalyst and...

Diffusion of Heavy Oil in SiO₂ Model Catalyst and FCC Catalyst

Abstract:

Through the measured effective diffusion coefficients of Dagang vacuum residue supercritical fluid extraction and fractionation (SFEF) fractions in FCC catalysts and SiO₂ model catalysts, the relation between pore size of catalyst and effective diffusion coefficient was researched and the restricted diffusion factor was calculated. The restricted diffusion factor in FCC catalysts is less than 1 and it is 1~2 times larger in catalyst with polystyrene (PS) template than in conventional FCC catalyst without template, indicating that the diffusion of SFEF fractions in the two FCC catalysts is restricted by the pore. When the average molecular diameter is less than 1.8 nm, the diffusion of SFEF fractions in SiO₂ model catalyst which average pore diameter larger than 5.6 nm is unrestricted. The diffusion is restricted in the catalyst pores of less than 8 nm for SFEF fractions which diameter more than 1.8 nm. The tortuosity factor of SiO₂ model catalyst is obtained to be 2.87, within the range of empirical value. The effective diffusion coefficient of the SFEF fractions in SiO₂ model catalyst is two orders of magnitude larger than that in FCC catalyst with the same average pore diameter. This indicate that besides the ratio of molecular diameter to the pore diameter λ, the effective diffusion coefficient is also closely related to the pore structure of catalyst. Because SiO₂ model catalyst has uniform pore size, the diffusion coefficient can be precisely correlated with pore size of catalyst, so it is a good model material for catalyst internal diffusion investigation.