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US 4,393,266 AGranted
Separation of para-xylene
AssigneeTexaco Inc.
InventorWilliam Smolin
Life of this patent
Estimating the term…
Abstract
Para-xylene may be separated as front-end product in high purity by contacting charge C-8 aromatic hydrocarbon mixture with certain NaY-type zeolites in the presence of a pyridine.
Claims22
The process for separating para-xylene from a feed mixture containing C-8 aromatic hydrocarbon including para-xylene which comprises
- contacting said feed mixture with, as an adsorbent, a pyridine or substituted pyridine-containing sodium Y zeolite, said sodium Y zeolite being characterized by a ratio of silicon to aluminum of 1.5-2.1 and by a pyridine or substituted pyridine content of at least about 3.3 w % based on said zeolite, thereby selectively adsorbing substantially all of said C-8 aromatic hydrocarbon to the substantial exclusion of para-xylene;
- and
- recovering said para-xylene.
The process for separating para-xylene from a feed mixture containing C-8 aromatic hydrocarbons including para-xylene which comprises
- contacting said feed mixture with, as an adsorbent, a pyridine or substituted pyridine-containing sodium Y zeolite, said sodium Y zerolite being characterized by a ratio of silicon to aluminum of 1.5-2.1 and by a pyridine or substituted pyridine content of at least about 3.3 w % based on said zerolite, in the presence of desorbent, thereby selectively adsorbing substantially all of said C-8 aromatic hydrocarbon to the substantial exclusion of para-xylene;
- contacting said adsorbent at desorption conditions with desorbent material having a boiling point substantially different from that of said feed mixture to effect withdrawal of the selectively adsorbed C-8 aromatic hydrocarbon;
- withdrawing from the adsorbent a raffinate stream containing less selectively adsorbed para-xylene;
- and
- withdrawing from said adsorbent an extract stream containing said selectively adsorbed C-8 aromatic hydrocarbon.
2 more elements
Dependencies are inferred from the claim text.