| 摘要 |
<p>PURPOSE:To carry out isomerization of xylene by treating a raw material composed of a mixture of xylene isomers and a small amount of non-aromatic hydrocarbons with a catalyst composed of a pentasil-type crystalline aluminosilicate zeolite and an amorphous refractory inorganic oxide supporting platinum, etc. CONSTITUTION:A raw material composed of a mixture of xylene isomers and 0.02-5wt.% of non-aromatic hydrocarbons is treated with a specific cracking catalyst to effect xylene-isomerization reaction and simultaneous decomposition of the non-aromatic hydrocarbon. A specific xylene isomer is separated from the system and the residual hydrocarbon mixture is recycled to the xylene isomerization reaction system. The cracking catalyst is composed of (A) a zeolite (e.g. ZSM-5) consisting of a pentasiltype crystalline aluminosilicate having a silica/alumina molar ratio of >=10 and containing alkali metal cations occupying >=20% of the cation sites and (B) an amorphous refractory inorganic oxide (e.g. gamma-alumina) supporting platinum, tin, hydrochloric acid, In, etc.</p> |
