Liquid phase aromatics alkylation process

A method for producing a gasoline boiling range product from a mixed light olefin feed stream including ethylene and propylene and a liquid aromatic feed stream including single ring aromatic compounds, which process comprises:

• extracting light olefins from an olefinic gas stream comprising ethylene and propylene by counterflow dissolution at a temperature up to 120° C. and a pressure up to 3500 kPag, into a stream of light aromatic hydrocarbons which contains benzene to form an extract stream comprising extracted olefins in the aromatic hydrocarbons and a stream comprising unsorbed olefins,
• alkylating the aromatics in the extract stream with the extracted olefins dissolved in the aromatic hydrocarbon stream over a fixed bed of a solid molecular sieve alkylation catalyst comprising a zeolite of the MWW family in a liquid phase reaction at a temperature of not more than 250° C. , an aromatics:olefin ratio from 0.5:1 to 5:1 by weight and an olefin space velocity from 0.5 to 5.0 WHSV, to form a gasoline boiling range product containing akylaromatics including alkylbenzenes,
• passing the stream comprising unsorbed olefins to a vapor phase alkylation step in which the olefins in this stream contact an additional stream of the aromatic feed to alkylate aromatics in the stream with unsorbed olefins in a fixed bed catalytic, vapor phase reaction over a catalyst comprising an intermediate pore size zeolite which is more active for ethylene conversion than the MWW type zeolite used in the liquid phase alkylation reaction, at a temperature which is higher than that used in the liquid phase alkylation step, to produce alkylate aromatics including alkylbenzenes.