Process for wet aromatic alkylation and dry aromatic transalkylation
AssigneeUop LLC
InventorsPeter J. Van Opdorp, Brian M. Wood
Life of this patent
Estimating the term…
Abstract
A process for the production of alkylaromatic hydrocarbons uses a high water content in an alkylation zone and a low water content in a transalkylation zone to improve yields improve process yields and catalyst life. An aromatic feed and an acyclic feed are first passed through the alkylation reaction zone that operates at a high water content. A separator receives the effluent from the alkylation reaction zone and removes water from a sidecut of unreacted aromatic feed. The sidecut of aromatic feed and a stream of polyalkylated aromatics are contacted in the transalkylation zone. The differing water content improves the operation of both the alkylation zone and the transalkylation zone.
Claims18
A process for the production of alkylaromatic hydrocarbons which comprises:
- a) contacting an aromatic feed hydrocarbon and an acyclic feed hydrocarbon in an alkylation reaction zone with an alkylation catalyst at alkylation conditions including a water concentration of at least 200 wppm to promote alkylation and recovering an alkylation reaction zone effluent comprising unconverted feed aromatic hydrocarbons, product aromatic hydrocarbons, and polyalkylated aromatic hydrocarbons;
- b) passing said alkylation reaction zone effluent and a transalkylation zone effluent to separation column, separting said alkylation reaction zone effluent and said transalkylation zone effluent, withdrawing an alkylate stream comprising said product hydrocarbons and said polyalkylated aromatic hydrocarbons as a bottoms stream for said column, withdrawing a first recycle stream comprising a first portion of said unconverted feed aromatic hydrocarbons and water as an overhead stream from said column, and withdrawing a second recycle stream comprising a second portion of said unconverted feed aromatic hydrocarbons and having a water concentration of less than 200 wppm as a sidecut from said column;
- c) separating said alkylate stream into a third recycle stream comprising said polyalkylated hydrocarbons and a product stream comprising said product hydrocarbons;
- and,
- (d) admixing said second and third recycle streams and contacting said second and third recycle streams with a zeolite transalkylation catalyst in a transalkylation reaction zone at transalkylation conditions that include a water concentration of less than 200 wppm, to provide said transalkylation zone effluent.
A process for the production of ethylbenzene that comprises:
- a) contacting a benzene feed and an ethylene feed in an alkylation reaction zone with an alkylation catalyst at alkylation conditions including a water concentration of at least 200 wppm to promote alkylation and recovering an alkylation reaction zone effluent comprising benzene, ethylbenzene, diethylbenzene and heavier aromatic hydrocarbons;
- b) passing said alkylation reaction zone effluent and a transalkylation reaction zone effluent to a separation column, withdrawing an alkylate stream comprising ethylbenzene, diethylbenzene, and heavier aromatic hydrocarbons from the bottom of said column, a first recycle stream comprising benzene as an overhead from said column, and a second recycle stream comprising benzene as a sidecut stream from said column said second recycle stream having a water concentration of less than 200 wppm water;
- c) separating said alkylate stream into an intermediate separation stream comprising said diethylbenzene and heavier hydrocarbons and a product stream comprising said ethylbenzene;
- d) separating said intermediate separation stream into a third recycle stream comprising said diethylbenzene and a heavy aromatic stream comprising said heavier hydrocarbons;
- and,
- e) admixing said second and third recycle streams and contacting said admixed first and second recycle streams with a transalkylation catalyst in a transalkylation reaction zone at transalkylation conditions that include a water concentration of less than 200 wppm to provide said transalkylation zone effluent.
Dependencies are inferred from the claim text.