Continuous processes for monoalkylating aromatic compound with an aliphatic feedstock comprising aliphatic olefin of 8 to 18 carbon atoms per molecule are effected using at least 3 reaction zones (104, 106a, 106b) in series, each containing solid alkylation catalyst with effluent cooling between reaction zones (104, 106a, 106b), each of which reaction zones is supplied a portion of the fresh aliphatic feedstock, such that the Reaction Zone Delta T in each reaction zone (104, 106a, 106b) is less than 15°C. The overall aromatic compound to olefin molar ratio is less than 20:1. The alkylation product has desirable linearity and low amounts of dimers, dealkylated compounds and diaryl compounds even though a low aromatic compound to olefin molar ratio is used.