This ethylbenzene process involves contacting, in an alkylation zone, a first benzene recycle stream and an ethylene feed stream with an alkylation catalyst to form ethylbenzene. In a transalkylation zone, a polyethylbenzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional ethylbenzene. The effluents are passed into a benzene distillation column. From the benzene distillation column, a first benzene recycle stream is removed as overhead; a second benzene recycle stream is removed as a side draw; and a bottoms stream comprising polyethylbenzene, ethylbenzene, and flux oil is removed from an end. The bottoms stream is passed to a dividing wall distillation column where the polyethylbenzene recycle stream is removed from an intermediate point; an ethylbenzene product stream is removed from a first end, and a heavy oil stream is removed from a second end.