The role of diffusion in alkyl-benzenes catalytic cracking

S. Al-Khattaf; H. De Lasa

doi:10.1016/S0926-860X(01)00895-X

The role of diffusion in alkyl-benzenes catalytic cracking

S. Al-Khattaf, H. De Lasa^*

^*Corresponding author for this work

King Fahd University of Petroleum & Minerals

Research output: Contribution to journal › Article › peer-review

105 Scopus citations

Abstract

The present study reports the catalytic cracking of three hydrocarbon model compounds: cumene, 1,3-di-iso-propyl-benzene (1,3-DIPB) and 1,3,5-tri-iso-propyl-benzene (1,3,5-TIPB). Experiments were developed in a novel CREC Riser Simulator, a catalytic reactor that mimics the operating conditions of large-scale fluid catalytic cracking (FCC) units. Reaction testing involved different reaction times and temperatures, using Y-zeolites of different crystal sizes (0.4 and 0.9μm). It was shown that cumene cracking and the cumene cracking products are unaffected by the zeolite crystal size. It was proven that 1,3-DIPB cracking; it remains unaltered with changes in crystal size with however, crystal dimensions affecting product selectivities. Regarding the 1,3,5-TIPB cracking, at 350-450°C using the 0.4μm Y-zeolites, higher 1,3,5-TIPB conversions were obtained. Differences on 1,3,5-TIPB conversions were however, less significant at 500-550°C. It is postulated that the 1,3,5-TIPB conversion differences are caused by constrained diffusional transport in the Y-zeolite crystals and that the increase of temperature changes the catalytic cracking of 1,3,5-TIPB from the diffusionally controlled regime to the kinetically controlled regime.

Original language	English
Pages (from-to)	139-153
Number of pages	15
Journal	Applied Catalysis A: General
Volume	226
Issue number	1-2
DOIs	https://doi.org/10.1016/S0926-860X(01)00895-X
State	Published - 28 Mar 2002

Bibliographical note

Funding Information:
The authors would like to express their appreciation to the King Fahd University of Petroleum and Minerals (KFUPM) that provided a postgraduate scholarship to Mr. S. Al-Khattaf. The authors are very grateful for the financial support of the Natural Sciences and Engineering Research Council of Canada. The authors would like to acknowledge the support of Dr. A. Humphries from Akzo Nobel and of J. Macaoay from Engelhard companies, who contributed significantly to this study with the preparation of the catalysts.

Keywords

Alkyl-benzenes
Catalytic cracking
Configurational diffusion
Riser Simulator
Zeolites

ASJC Scopus subject areas

Catalysis
Process Chemistry and Technology

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10.1016/S0926-860X(01)00895-X

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title = "The role of diffusion in alkyl-benzenes catalytic cracking",

abstract = "The present study reports the catalytic cracking of three hydrocarbon model compounds: cumene, 1,3-di-iso-propyl-benzene (1,3-DIPB) and 1,3,5-tri-iso-propyl-benzene (1,3,5-TIPB). Experiments were developed in a novel CREC Riser Simulator, a catalytic reactor that mimics the operating conditions of large-scale fluid catalytic cracking (FCC) units. Reaction testing involved different reaction times and temperatures, using Y-zeolites of different crystal sizes (0.4 and 0.9μm). It was shown that cumene cracking and the cumene cracking products are unaffected by the zeolite crystal size. It was proven that 1,3-DIPB cracking; it remains unaltered with changes in crystal size with however, crystal dimensions affecting product selectivities. Regarding the 1,3,5-TIPB cracking, at 350-450°C using the 0.4μm Y-zeolites, higher 1,3,5-TIPB conversions were obtained. Differences on 1,3,5-TIPB conversions were however, less significant at 500-550°C. It is postulated that the 1,3,5-TIPB conversion differences are caused by constrained diffusional transport in the Y-zeolite crystals and that the increase of temperature changes the catalytic cracking of 1,3,5-TIPB from the diffusionally controlled regime to the kinetically controlled regime.",

keywords = "Alkyl-benzenes, Catalytic cracking, Configurational diffusion, Riser Simulator, Zeolites",

author = "S. Al-Khattaf and \{De Lasa\}, H.",

note = "Funding Information: The authors would like to express their appreciation to the King Fahd University of Petroleum and Minerals (KFUPM) that provided a postgraduate scholarship to Mr. S. Al-Khattaf. The authors are very grateful for the financial support of the Natural Sciences and Engineering Research Council of Canada. The authors would like to acknowledge the support of Dr. A. Humphries from Akzo Nobel and of J. Macaoay from Engelhard companies, who contributed significantly to this study with the preparation of the catalysts.",

year = "2002",

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doi = "10.1016/S0926-860X(01)00895-X",

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AU - Al-Khattaf, S.

AU - De Lasa, H.

N1 - Funding Information: The authors would like to express their appreciation to the King Fahd University of Petroleum and Minerals (KFUPM) that provided a postgraduate scholarship to Mr. S. Al-Khattaf. The authors are very grateful for the financial support of the Natural Sciences and Engineering Research Council of Canada. The authors would like to acknowledge the support of Dr. A. Humphries from Akzo Nobel and of J. Macaoay from Engelhard companies, who contributed significantly to this study with the preparation of the catalysts.

PY - 2002/3/28

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N2 - The present study reports the catalytic cracking of three hydrocarbon model compounds: cumene, 1,3-di-iso-propyl-benzene (1,3-DIPB) and 1,3,5-tri-iso-propyl-benzene (1,3,5-TIPB). Experiments were developed in a novel CREC Riser Simulator, a catalytic reactor that mimics the operating conditions of large-scale fluid catalytic cracking (FCC) units. Reaction testing involved different reaction times and temperatures, using Y-zeolites of different crystal sizes (0.4 and 0.9μm). It was shown that cumene cracking and the cumene cracking products are unaffected by the zeolite crystal size. It was proven that 1,3-DIPB cracking; it remains unaltered with changes in crystal size with however, crystal dimensions affecting product selectivities. Regarding the 1,3,5-TIPB cracking, at 350-450°C using the 0.4μm Y-zeolites, higher 1,3,5-TIPB conversions were obtained. Differences on 1,3,5-TIPB conversions were however, less significant at 500-550°C. It is postulated that the 1,3,5-TIPB conversion differences are caused by constrained diffusional transport in the Y-zeolite crystals and that the increase of temperature changes the catalytic cracking of 1,3,5-TIPB from the diffusionally controlled regime to the kinetically controlled regime.

AB - The present study reports the catalytic cracking of three hydrocarbon model compounds: cumene, 1,3-di-iso-propyl-benzene (1,3-DIPB) and 1,3,5-tri-iso-propyl-benzene (1,3,5-TIPB). Experiments were developed in a novel CREC Riser Simulator, a catalytic reactor that mimics the operating conditions of large-scale fluid catalytic cracking (FCC) units. Reaction testing involved different reaction times and temperatures, using Y-zeolites of different crystal sizes (0.4 and 0.9μm). It was shown that cumene cracking and the cumene cracking products are unaffected by the zeolite crystal size. It was proven that 1,3-DIPB cracking; it remains unaltered with changes in crystal size with however, crystal dimensions affecting product selectivities. Regarding the 1,3,5-TIPB cracking, at 350-450°C using the 0.4μm Y-zeolites, higher 1,3,5-TIPB conversions were obtained. Differences on 1,3,5-TIPB conversions were however, less significant at 500-550°C. It is postulated that the 1,3,5-TIPB conversion differences are caused by constrained diffusional transport in the Y-zeolite crystals and that the increase of temperature changes the catalytic cracking of 1,3,5-TIPB from the diffusionally controlled regime to the kinetically controlled regime.

KW - Alkyl-benzenes

KW - Catalytic cracking

KW - Configurational diffusion

KW - Riser Simulator

KW - Zeolites

UR - https://www.scopus.com/pages/publications/0037187495

U2 - 10.1016/S0926-860X(01)00895-X

DO - 10.1016/S0926-860X(01)00895-X

M3 - Article

AN - SCOPUS:0037187495

SN - 0926-860X

VL - 226

SP - 139

EP - 153

JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

IS - 1-2

ER -

The role of diffusion in alkyl-benzenes catalytic cracking

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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