Chemical Research & Licensing Company

Abb Lummus Crest, Inc.

Other

Angel Sy

In the alkylation of benzene with propylene in a distillation column reactor to produce cumene the overheads from the distillation reactor are fed to a depropanizer where the unreacted benzene is separated from C.sub.3 's. Liquid propylene feed for the distillation column reactor is vaporized by indirect heat exchange with the overheads from the depropanizer to condense the overheads, thereby reducing the pressure in the depropanizer below what would be normally achieved with conventional condensing systems.

Process for depropanizing benzene

To heat the circulating reboiler streams of multiple distillation columns a fired reboiler is provided for a first column requiring the most heat. A portion of the bottoms from the first column is passed through the tubes of the heater in the fired reboiler and recycled to the first column as is normal. A slip stream is taken from the recycle after heating and passed on to provide heat by indirect heat exchange to a second reboiler and if desired other reboilers or heat exchangers. The slip stream may then be recycled to the bottoms of the first column directly or to the circulating steam of the first reboiler. A portion of the recycled slip stream can be taken as feed into the second column.

Multiple reboiler system

A system for the catalytic distillation production of alkylated aromatic compounds is provided wherein the vapor pressure of the olefin may be increased while maintaining the same olefin feed rate and aromatic to olefin ratio. In one embodiment a side stream from the vapor from the second column below the catalyst and olefin feed is condensed and rerouted to the aromatic make up stream from the reflux drum. The vapor pressure of the olefin in the lower end of the first column in the catalyst bed is thus increased which increases the equilibrium concentration of the olefin in the liquid phase. In another embodiment of the invention the effective driving force for the reaction is increased by injecting the olefin at different heights within the catalyst bed. If additional olefin is injected more catalyst bed height would be required, but the additional catalyst is more that offset by the increased throughput at the same overall olefin conversion. The practice of injecting the olefin feed at different heights is especially useful when the same olefin feed rate is used but split among the several streams because less catalyst is required.

Aromatic alkylation process

A process for the catalytic distillation production of alkylated aromatic compounds is provided wherein the vapor pressure of the olefin may be increased while maintaining the same olefin feed rate and aromatic to olefin ratio. In one embodiment a side stream from the vapor from the second column below the catalyst and olefin feed is condensed and rerouted to the aromatic make up stream from the reflux drum. The vapor pressure of the olefin in the lower end of the first column in the catalyst bed is thus increased which increases the equilibrium concentration of the olefin in the liquid phase. In another embodiment of the invention the effective driving force for the reaction is increased by injecting the olefin at different heights within the catalyst bed. If additional olefin is injected more catalyst bed height would be required, but the additional catalyst is more that offset by the increased throughput at the same overall olefin conversion. The practice of injecting the olefin feed at different heights is especially useful when the same olefin feed rate is used but split among the several streams because less catalyst is required.

Growing community of inventors

Katy, TX, United States of America

Angel Sy