| 摘要 |
<p>A process for separating the ortho-isomer from a feed mixture comprising at least two bi-alkyl substituted monocyclic aromatic isomers, including the ortho-isomers, the isomers having from 9 to about 18 carbon atoms per molecule. The process comprises contacting, at adsorption conditions, the feed with an adsorbent comprising a crystalline aluminosilicate consisting essentially of a sodium or calcium Y-type zeolite or sodium X-type zeolite which selectively adsorbs the ortho-isomers. The feed is removed from the adsorbent, and the ortho-isomers recovered by desorption at desorption conditions with a desorbent material comprising a C<Sub>8</Sub> or heavier monocyclic aromatic with a boiling point at least 5°C different than that of the feed mixture when the adsorbent is the sodium Y-type zeolite, or a C<Sub>a</Sub> or lighter moncyclic aromatic when the adsorbent is a sodium X or calcium Y-type zeolite.</p><p>The process is particularly amenable to the employment of a simulated moving bed flow scheme.</p> |
