Study on Heterogeneously Catalyzed Oligomerization of Glycerol over Alumina Supported Calcium-Lanthanum Mixed Oxides

Abstract

In this work the solvent-less etherification of glycerol in presence of calcium–lanthanum oxides supported on alumina as catalysts was studied The catalysts were successfully prepared by the wetness impregnation method using La(NO3)3 and Ca(NO3)2 solutions as well as boehmite as the support and subsequently by calcination at 600 ?C Various instruments including BET TPD XRD SEM and ICP-OES analysis was employed for characterization of these catalysts Typically the etherification reactions of glycerol as both reactant and solvent were carried out at 250 °C in nitrogen atmosphere Under the optimal reaction conditions near 72% glycerol could be converted to glycerol oligomers after 8h using Ca-La/alumina catalysts prepared from mixed solutions of Ca+2/La+3 in which the molar ratio of Ca/La is 2 7/1 with a loading as 2 wt% based on the initial mass of glycerol A selectivity of 81% for di- and tri-glycerol in linear form could be achieved accordingly Moreover this catalyst showed good reusability and stability For example near 62% in glycerol conversion and ca 73% as selectivity of di- and tri-glycerol could be obtained with the recycled catalysts after the second sequential run

Date of Award	2019
Original language	English
Supervisor	Bing-Hung Chen (Supervisor)