Patent ID: 8609916

Claim:
A process for preparing alkylated aromatic compounds, the process comprising the steps of: reacting an aromatic compound and an olefin in at least one primary alkylation reaction in the presence of a first alkylation catalyst to produce a first effluent comprising an alkylated aromatic compound and an unreacted aromatic compound; splitting the first effluent into a first product-rich stream and a first recycle stream; recycling the first recycle stream to the at least one primary alkylation reaction; reacting the unreacted aromatic compound from the first product-rich stream and an additional olefin in at least one downstream alkylation reaction in the presence of a second alkylation catalyst to produce a second effluent comprising the alkylated aromatic compound; splitting the second effluent into a second product-rich stream and a second recycle stream; recycling the second recycle stream to the at least one primary alkylation reaction and, optionally, to the at least one downstream alkylation reaction; and wherein the first recycle stream is recycled to the at least one primary alkylation reaction in an amount of at least 20% by weight based upon a total combined amount of the first recycle stream and the second recycle stream recycled to the at least one primary alkylation reaction, and wherein the first recycle stream and the second recycle stream are recycled to the at least one primary alkylation reaction at a ratio of total recycle stream to a total mass flow in the at least one primary alkylation reaction is between 0.5:1 and 6:1, and wherein reacting the aromatic compound and the olefin in the at least one primary alkylation reaction is further defined as reacting benzene with ethylene or propylene to produce the first effluent comprising ethylbenzene or cumene.