Summary: Xylene Transformation over USY Zeolite: An Experimental and Kinetic Study
Iliyas, A. and Al-Khattaf, S.*
Department of Chemical Engineering, King Fahd University of Petroleum &
Minerals, Dhahran 31261, Saudi Arabia.
A systematic study on the influence of reaction conditions (temperature, time, and
reactant type) on the selectivity of xylene transformation has been carried out over USY
zeolite. Initial product selectivity revealed that both isomerization and disproportionation
of xylenes are primary reactions. Higher conversion was observed with p-xylene reactant
as compared to m- and o-xylene. The "reactant converted" deactivation model was tested
with xylenes as model compounds, using effective, mechanistic kinetic models, developed
from the transformation of each xylene isomers. The parameters optimized to the
experimental data gave a good prediction of the overall reaction kinetics for the xylene
transformations. The results provide significant evidence that the "reactant converted"
decay model can be adequately utilized to account for catalyst deactivation of the xylene
Keywords: Xylene transformation, catalyst deactivation model, kinetic modeling, USY
zeolite, fluidized-bed reactor.
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