Study On The Preparation Of Linalyl Acetate From Dehydrolinalool By Esterification And Selective Hydrogenation

The way of synthetizing linalyl acetate by hydrogenation of products from esterification of dehydrolinalool and acetic anhydride was studied in this paper. The first step is to synthetize dehydrolinalyl acetate from esterification by dehydrolinalool and acetic anhydride catalyzed by different kinds of catalysts, then collect purified dehydrolinalyl acetate to be the raw material for hydrogenation in trickle bed reactor to produce linalyl acetate.Three different kinds of catalysts have been used in the esterification reaction: sulfosalicylic acid,p-toluenesulfonic aci,strong acid cation-exchange resin. The results showed that the activity of organic acid catalyst is higher than the activity of strong acid resin, so the amount of catalyst is much lower, and reaction condition is moderate. As a catalyst, strong acid cation-exchange resin is a little low in activity, but more convenient to separate from product.Pd/Al2O3 catalyst was studied and prepared into the hydrogenation of dehydrolinalyl acetate to linalyl acetate, and the selectivity of catalyst can be improved by the addition of cocatalysts. Results exhibited both of the conversion and selectivity as 95% and 85% under reaction conditions as below:reaction temperature of 60℃, pressure of 1.5MPa, with VDHLA:VEtOH=1:1, H2 flow rate of 12.7mL/min and liquid space velocity of 0.8h-1.