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US 7,605,295 B1Granted
Integrated process yielding xylenes from mixed aromatics
AssigneeUop LLC
InventorsDavid S. Lafyatis, Edwin P. Boldingh, Antoine Negiz, Edward M. Casey
Life of this patent
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Abstract
The subject invention comprises an aromatics complex to improve yields from a mixed aromatics feed. Through the use of a novel catalyst having higher activity and stability in a transalkylation unit in the complex, a higher xylene yield is obtained.
Claims16
A process for producing xylenes from an aromatics-rich feed stream comprising the steps of:
- (a) separating the aromatics-rich feed stream and a transalkylation product stream in a fractionation zone to produce a benzene-rich stream, a toluene-rich stream, a C8-aromatics product and C9-and-heavier stream;
- (b) fractionating the C9-and-heavier stream in a heavy-aromatics fractionator to obtain a C9-C11+ heavy transalkylation feed and a C12+ residual stream;
- (c) combining the toluene-rich stream and C9-C11+ heavy transalkylation feed to obtain a combined transalkylation feed and contacting the combined feed in a transalkylation zone under transalkylation conditions with a transalkylation catalyst which comprises (1) an aggregate zeolitic material comprising globular aggregates of crystallites having a MOR framework type comprising 12-ring channels, a mesopore volume of at least about 0.10 cc/gram, a mean crystallite length parallel to the direction of the 12-ring channels of about 60 nm or less, the number of 12-ring channel-openings per gram of zeolite of at least 1×1019, and a silica-alumina (Si/Al2) mole ratio of from about 8 to about 50, (2) a binder comprising one or more of alumina, silica, silica-alumina, aluminum phosphate, and (3) a metal component selected from the group consisting of groups VIB(6), VIIB(7), VIII(8-10) and IVA(14) of the Periodic Table, and mixtures thereof, to produce the transalkylation product stream of step (a) having an increased concentration of xylenes relative to the combined transalkylation feed.
A process for producing xylenes from an aromatics-rich feed stream comprising the steps of:
- (a) separating the aromatics-rich feed stream and a transalkylation product stream in a fractionation zone to produce a benzene-rich stream, a toluene-rich stream, a C8-aromatics product and C9-and-heavier stream,
- (b) combining the toluene-rich stream and C9-and-heavier stream to obtain a combined transalkylation feed and contacting the combined feed in a transalkylation zone under transalkylation conditions with a transalkylation catalyst which comprises (1) an aggregate zeolitic material comprising globular aggregates of crystallites having a MOR framework type comprising 12-ring channels, a mesopore volume of at least about 0.10 cc/gram, a mean crystallite length parallel to the direction of the 12-ring channels of about 60 nm or less, the number of 12-ring channel-openings per gram of zeolite of at least 1×1019, and a silica-alumina (Si/Al2) mole ratio of from about 8 to about 50, (2) a binder comprising one or more of alumina, silica, silica-alumina, aluminum phosphate, and (3) a metal component selected from the group consisting of groups VIB(6), VIIB(7), VIII(8-10) and IVA(14) of the Periodic Table, and mixtures thereof, to produce the transalkylation product stream of step (a) having an increased concentration of xylenes relative to the combined transalkylation feed.
A process for producing xylenes from an aromatics-rich feed stream comprising the steps of:
- (a) combining the aromatics-rich feed stream with recycled heavy aromatics and a recycled toluene-rich stream to obtain a combined transalkylation feed and contacting the combined feed in a transalkylation zone under transalkylation conditions with a transalkylation catalyst which comprises (1) an aggregate zeolitic material comprising globular aggregates of crystallites having a MOR framework type comprising 12-ring channels, a mesopore volume of at least about 0.10 cc/gram, a mean crystallite length parallel to the direction of the 12-ring channels of about 60 nm or less, the number of 12-ring channel-openings per gram of zeolite of at least 1×1019, and a silica-alumina (Si/Al2) mole ratio of from about 8 to about 50, (2) a binder comprising one or more of alumina, silica, silica-alumina, aluminum phosphate, and (3) a metal component selected from the group consisting of groups VIB(6), VIIB(7), VIII(8-10) and IVA(14) of the Periodic Table, and mixtures thereof to produce a transalkylation product stream having an increased concentration of xylenes relative to the combined transalkylation feed;
- (b) separating the transalkylation product stream in a fractionation zone to produce a benzene-rich stream, a toluene-rich recycle stream, a C8-aromatics product and C9-and-heavier stream;
- and
- (c) fractionating the C9-and-heavier stream in a heavy-aromatics fractionator to obtain recycled heavy aromatics and a C12+ residual product stream.
1 more element
Dependencies are inferred from the claim text.