Methylation of toluene over ZSM-5
zeolites modified by the introduction of Sr of 2.5%, 5%, and 10% by weight was
studied. Experiments were performed in a fixed bed under the conditions
of reaction temperatures
between 300°C-500°C, liquid hour space velocity of 4 g
toluene/h.g catalyst, methanol to toluene ratio 4:1, and 0.01% of N-Octyl-N-benzyl-N-methylglycine
as emulsifier.Data for conversion of toluene and selectivity
towards xylene isomers showed that 2.5% Sr/ZSM-5 catalyst has the highest
conversion of toluene at 500°C, and the lowest p-xylene selectivity, while 10%
Sr/ZSM-5 catalyst has the highest selectivity for p-xylene production. Nevertheless,
the catalyst 2.5% Sr/ZSM-5 has the highest selectivity for m-xylene. The two
catalysts 2.5% and 5% Sr/ZSM-5 give nearly the same selectivity for the three
xylene isomers at all conversions obtained at the reaction conditions under
study.
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