No abstract

The oligomerization of propene, as well as the alkylation of benzene and toluene with propene, was evaluated at 160-240°C, 3.8 MPa, and aromatic to olefin ratios of 1:6 to 6:1 using solid phosphoric acid (SPA) as a catalyst. It was found that steric effects were more important than electronic effects in determining alkylation rate and selectivity. Monoalkylation was favored even at the lowest aromatic to olefin ratio, and the isomer distribution of dialkylated aromatics remained constant irrespective of the conversion or operating conditions. No transalkylation or alkylbenzene isomerization activity was observed. It was shown that olefin oligomerization and aromatic alkylation could be combined in a single SPA catalyzed reaction system to produce a synthetic jet fuel that meets Jet A-1 specifications.

A refinery with a solid phosphoric acid olefin oligomerization unit can reduce the benzene content of its motor-gasoline by co-feeding the benzene-containing material to that unit. It has been shown that benzene co-feeding has little disruptive impact on olefin oligomerization, and >80% benzene conversion to alkylated benzenes has been demonstrated during a commercial test run on an industrial unit. Benzene conversion is insensitive to reactor inlet temperature in the range of 160-180 °C and remains better than 80% at liquid hourly space velocities of up to 1.5 h -1 . A high propene content in the olefinic feed promotes benzene alkylation, and although butene-rich feeds can be employed, benzene conversion is lower.