丙烯醚化合成二异丙醚催化剂研究

The catalytic properties of Hβ, ZSM-5 zeolites and resin were compared in propylene hydration-etherification to produce diisopropyl ether (DIPE). The influence of promoters (both type and amount) on the Hβ zeolite pore structure, acidity and activity was examined. The results showed that the etherification property of Hβ is superior to ZSM-5; Hβ zeolite is suitable for etherification reaction, while resin has advantage in hydration reaction to product IPA. As the promoters of Hβ zeolite, TiO2, ZrO2, the alkaline-earth metal, the rare-earth elements and the VB elements can reduce the amount of Bronsted acid on Hβ zeolite, but increase the amount of Lewis acid on Hβ zeolite. Larger amounts of Lewis acid and total acid on Hβ zeolite can benefit the production of DIPE, but the pore structure has less influence on it. TiO2 can increase DIPE selectivity and yield, but contribute nothing to propylene conversion; ZrO2 can enhance DIPE selectivity, propylene conversion and DIPE yield，but can produce also more by-products such as acetone and C6; Adding the alkaline-earth metal, the rare-earth elements and the VB elements simultaneously can improve catalytic activity of Hβ zeolite obviously. At a suitable operating conditions (165 ℃, 7.0 MPa, n(water)/n(propylene) ratio of 0.5 and a LHSV of 0.5 h－1, the initial yield of the catalyst made by adding these elements could reach 39% at optimum conditions, and decreased by 3% after running for 1 000 h.