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US 10,308,571 B2Granted
Process for minimizing benzene, toluene, and a recycle loop in a zero benzene aromatics complex
AssigneeUop LLC
InventorsElizabeth A. Carter, Deng-Yang Jan, Timur V. Voskoboynikov
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Abstract
The present invention relates to minimizing benzene, toluene, and an A9/A10 recycle loop in a zero benzene aromatics complex. More specifically, the present invention relates to a minimizing benzene, toluene, and an A9/A10 recycle loop in a zero benzene aromatics complex wherein the aromatic feed has a low methyl to phenyl ratio, and where the aromatic feed has a high methyl to phenyl ratio.
Claims18
A process for reducing benzene in an aromatics complex, comprising:
- passing an aromatics stream having a methyl to phenyl ratio above 1.0 to a benzene column to produce a benzene column overhead stream comprising benzene and a benzene column bottoms stream comprising toluene and aromatics having 9+ carbons;
- passing the benzene column overhead stream to a trans-alkylation unit and transalkylating aromatics having 9+ carbons with benzene to produce a benzene trans-alkylation product stream;
- passing the benzene column bottoms stream to a toluene column to produce a toluene column overhead stream comprising toluene and a toluene column bottoms stream comprising aromatics having 9+ carbon;
- passing a first portion of the toluene column overhead stream to the trans-alkylation unit and transalkylating aromatics having 9+ carbons with toluene to produce a toluene transalkylation product stream;
- passing a second portion of the toluene column overhead stream to a toluene methylation unit to produce a toluene methylation unit product stream containing xylenes with para-xylene selectivity between 20% and 99.9% within the xylenes;
- passing the toluene column bottoms stream to a fractionation zone to produce an overhead stream comprising xylenes, a bottoms stream comprising heavy aromatics, and a middle boiling fraction comprising aromatics having 9-10 carbons;
- passing the middle boiling fraction from the fractionation zone to the trans-alkylation unit;
- recycling the benzene trans-alkylation product stream to the benzene column;
- and,
- recycling the toluene methylation unit product stream to the benzene column.
7 more elements
A process for reducing benzene in an aromatics complex, comprising:
- passing an aromatics stream having a methyl to phenyl ratio above 1.5 to a benzene column to produce a benzene column overhead stream comprising benzene and a benzene column bottoms stream comprising toluene and aromatics having 9+ carbons;
- passing the benzene column overhead stream to a trans-alkylation unit;
- passing the benzene column bottoms stream to a toluene column to produce a toluene column overhead stream comprising toluene and a toluene column bottoms stream comprising aromatics having 9+ carbon;
- passing a first portion of the toluene column overhead stream to the trans-alkylation unit;
- transalkylating aromatics having 9+ carbons with toluene from the first portion of the toluene column overhead stream and with benzene from the benzene column overhead stream to produce a transalkylation product stream;
- passing a second portion of the toluene column overhead stream to a toluene methylation unit to produce a toluene methylation unit product stream;
- passing the toluene column bottoms stream to a fractionation zone to produce an overhead stream comprising xylenes, a bottoms stream comprising heavy aromatics, and a middle boiling fraction comprising aromatics having 9-10 carbons;
- passing the middle boiling fraction from the fractionation zone to the trans-alkylation unit;
- recycling the benzene trans-alkylation product stream to the benzene column;
- and,
- recycling the toluene methylation unit product stream to the benzene column.
8 more elements
Dependencies are inferred from the claim text.