PURPOSE: To selectively obtain the product rich in benzene and p-xylene that contains no following impurities having close boiling points to that of toluene, in other words, from which the impurities can be readily separated by simple distillation by allowing an impure toluene flow containing non-aromatic impurities having boiling points close to that of toluene to contact with a specific catalyst.
CONSTITUTION: A toluene-containing feedstock comprising >70% toluene (A) and 0.2-5 wt.% of close-boiling non-aromatic impurities (AI) (for example, a product that is prepared by aromatization of paraffinic feedstock over a nonacidic catalyst with an α value of <10 as L-zeolite) is passed over (B) an acidic intermediate pore zeolite that has an α value of >10 and high para- selectivity (for example, ZSM-5 molecular sieve catalyst that is selected by coking so that it contains 1-40% of coke) at 700-1,200°F to produce the objective product rich in benzene and p-xylene with the AI content reduced.
ROBAATO EI INESU
AANORUDO JIEI GUROIN
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