HY zeolite catalyst for alkylation of α-methylnaphthalene with long-chain alkenes

The Friedel–Crafts alkylation reactions of α-methylnaphthalene with long-chain alkenes (C11–12) in liquid-phase over environmentally friendly zeolite catalysts, HY and Hβ, had been investigated first. HY was chosen for its excellent catalytic performance. Both gas chromatography and gas chromatography mass spectroscopy were used as the appraisal methods for alkylation technology, the effects of various parameters like catalyst pretreatment temperature (Tc), HY content of HY/Al2O3 catalysts (CHY%), graininess of catalysts, reaction temperature (Tr), pressure, mole ratio of α-methylnaphthalene to olefins (nrea), solvent dosage (nsol) and volume hour space velocity (VHSV) on the reaction were studied in detail. The possible mechanism for the alkylation of α-methylnaphthalene with long-chain olefins over HY zeolite was proposed. The optimum parameters had been found. 60–80% HY content of HY/Al2O3 was used as catalyst, sieved into 20–60 meshes, and pretreated at 813 K for an hour. Molar ratio of α-methylnaphthalene to olefins and cyclohexane to α-methylnaphthalene were 8–10:1 and 2–4:1, respectively. The volume hour space velocity (VHSV) was 5–7 mL h−1 g−1 cat. The reaction was carried out at 453–473 K of reaction temperature and 1.0 MPa of system pressure. On the basis of the optimum reaction parameters, more than 90% conversion of alkenes (time on stream, TOS is 4 h) and 100% selectivity for desired mono alkylmethylnaphthalene were obtained. HY zeolite could be a practical catalyst for alkylation of α-methylnaphthalene with long-chain alkenes.