الفهرس | Only 14 pages are availabe for public view |
Abstract Summary The main goal of this study was devoted to find an active, eco-friendly and lowcost catalyst able to efficiently esterify acetic acid with n-butyl, iso-amyl, benzyl and cinnamyl alcohols at low temperatures with100% selectivities. Natural silica was provided from the western dessert of Egypt. The obtained solid was sieved to 0. 25mm, and finally calcined at 200-600°C in a muffle furnace in static air atmosphere for 3h. The catalysts were characterized by (TG & DTA) , XRF, XRD, FTIR, SEM and acidity. The results of catalytic activity indicated that natural silica calcined at 200°C is an active and selective catalyst towards the esterification of acetic acid with n-butyl, iso-amyl, benzyl and cinnamyl alcohols. In addition, the different factors that affect the catalytic activity were studied. These factors are, reflux time, molar ratio, reaction temperature, calcination temperature, and recycling of catalysts. The maximum yields from the reaction mixture (batch method) of n-butyl, iso-amyl, benzyl and cinnamyl acetates were 86, 80, 81 and 83% respectively, with selectivity of 100%. In addition, the maximum yields after simple distillation of n-bulyl, iso-amyl, benzyl and cinnamyl esters were 99.5%, 98.0%, 97.0 and 90.0%, respectively. Finally, results of recycling indicated that, natural silica is reusable catalyst where only slightly decrease in the conversion was observed after four cycles of using |