Non-aromatic compound removal systems for para-xylene production
AssigneeExxonMobil Technology and Engineering Company
InventorsBhupender S. Minhas, Jeevan S. Abichandani, Marcus L. H. van Nuland, Wai Kit Cheng, Chong-Jhoo Wang, Robert G. Tinger
Life of this patent
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Abstract
Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.
Claims9
A method for removing non-aromatic compounds from a para-xylene production process, comprising:
- feeding a reformate stock stream into a xylene recycle loop comprising a xylene splitter, a para-xylene recovery unit, a membrane unit, an isomerization unit, a deheptanizer unit, and a clay treater;
- producing, via the xylene splitter configured to receive the reformate stock stream, a mixed xylene stream comprising para-xylene, ortho-xylene, and meta-xylene;
- producing, via the para-xylene recovery unit configured to receive the mixed xylene stream, a para-xylene lean stream;
- permeating xylene in the para-xylene lean stream via the membrane unit to separate a non-aromatics rich stream from a membrane unit product stream;
- processing the membrane unit product stream in the isomerization unit to produce an isomerization unit product stream;
- producing, via the deheptanizer unit configured to receive the isomerization unit product stream, a xylene rich stream;
- processing the xylene rich stream through the clay treater to produce a clay treated stream;
- and
- feeding the clay treated stream into the xylene splitter for recirculation within the xylene recycle loop.
Dependencies are inferred from the claim text.