TY - JOUR
T1 - Dehydroisomerization of n-Butane over Pt-ZSM5
T2 - II. Kinetic and Thermodynamic Aspects
AU - Pirngruber, G. D.
AU - Seshan, K.
AU - Lercher, J. A.
N1 - Funding Information:
This work was performed under the auspices of NIOK, the Netherlands Institute of Catalysis Research. IOP Katalyse (IKA 94023) is gratefully acknowledged for financial support, and M. J. G. Janssen, from Exxon Chemical International Inc., Basic Chemicals Technology Europe, for supplying the ZSM5 samples.
PY - 2000/3/10
Y1 - 2000/3/10
N2 - A kinetic model is applied to describe the dehydroisomerization of n-butane to isobutene over Pt-ZSM5. It is compared with experimental data and used to show how a combination of kinetics and thermodynamics affects the obtained yields. High temperatures reduced the selectivity to by-product formation by oligomerization/cracking of butenes. However, the stability of the catalyst decreased. This is attributed to the enhanced formation of butadiene, poisoning metal and acid sites. Lowering the pressure also reduced the selectivity to by-products and the thermodynamic constraints and was, thus, favorable for dehydroisomerization. The H2/n-butane ratio mainly affected the selectivity to hydrogenolysis, which increased with hydrogen partial pressure, while catalyst stability did not improve significantly. An optimum with respect to selectivity and stability was found for a H2/n-butane ratio of 2.
AB - A kinetic model is applied to describe the dehydroisomerization of n-butane to isobutene over Pt-ZSM5. It is compared with experimental data and used to show how a combination of kinetics and thermodynamics affects the obtained yields. High temperatures reduced the selectivity to by-product formation by oligomerization/cracking of butenes. However, the stability of the catalyst decreased. This is attributed to the enhanced formation of butadiene, poisoning metal and acid sites. Lowering the pressure also reduced the selectivity to by-products and the thermodynamic constraints and was, thus, favorable for dehydroisomerization. The H2/n-butane ratio mainly affected the selectivity to hydrogenolysis, which increased with hydrogen partial pressure, while catalyst stability did not improve significantly. An optimum with respect to selectivity and stability was found for a H2/n-butane ratio of 2.
KW - Bifunctional catalysis
KW - Dehydroisomerization
KW - Kinetic modeling
KW - Pt-ZSM5
UR - http://www.scopus.com/inward/record.url?scp=0001231772&partnerID=8YFLogxK
U2 - 10.1006/jcat.1999.2753
DO - 10.1006/jcat.1999.2753
M3 - Article
AN - SCOPUS:0001231772
SN - 0021-9517
VL - 190
SP - 338
EP - 351
JO - Journal of Catalysis
JF - Journal of Catalysis
IS - 2
ER -