Study Of Acetone Condensation To Isophorne Over Solid Catalysts

As an important raw material of fine chemical and intermediates, the uses of isophorone arevery extensive and it has high added value. In recent years, the condensation of vapour phaseacetone to isophorone is a way of green process route. With the importance of this way, at homeand abroad the research on the solid catalyst which is used were more and more widely.A series of MgCaAl composite acid-base compound catalyst were prepared bycoprecipitation method, used ammonia as the precipitating agent,tested in a fixed-bed reactor.The structure and properties of these catalysts were characterized by means of XRD and TPD.Compared with binary MgAl compounds, the catalytic properties of ternary MgCaAl system arebetter.Meanwhile, the main factors affecting activity of catalysts were investigated. The resultsshowed that: parallel flow coprecipitation, the catalysts of MgCaAl molar ratio of 10:1:10, pH≈9.0, the crystallization temperature 70℃, calcination temperature 600℃have the nice activity.The conversion of acetone and the selectivity of isophorone maintains at 32.8% and 84.8%.Then the reaction conditions such as reaction temperature and diluent agent werediscussed,experimental results reveal that reducing the reaction temperature properly ispropitious to inhibit formation of high boiling products. The conversion of acetone and theselectivity of isophorone maintains at 32.3% and 86.5%. And, the diluent agent is helpful forsynthesis of isophorone.From the above experiments, the existence of acid and basic centers on the surface ofMgCaAl complex oxides are favorable for the synthesis of isophorone, and this catalyst has goodstability.