Vol.:(0123456789) Reaction Kinetics, Mechanisms and Catalysis https://doi.org/10.1007/s11144-019-01594-w 1 3 Microwave‑irradiated acetylation of glycerol catalyzed by acid activated clays Laís Pastre Dill 1  · Débora Merediane Kochepka 1  · André Melinski 1  · Fernando Wypych 1  · Claudiney Soares Cordeiro 1 Received: 6 February 2019 / Accepted: 24 May 2019 © Akadémiai Kiadó, Budapest, Hungary 2019 Abstract In this study, the investigation of the efects related to glycerol and acetic acid esteri- fcation over solid acid catalysts under microwave radiation by full factorial design 2 3 is described. Using clay minerals activated with H 3 PO 4 as catalysts it was pos- sible to produce 26.4 wt% of acetins with molar ratio of 1:3 (glycerol:acetic acid), at 90 °C and using 10 wt% catalysts (in relation to glycerol mass) in 1 h of reaction. On the other hand, under the same conditions and conventional heating, 22.5 wt% of acetins were obtained, without selectivity, while under microwave radiation 67% of produced acetins were monoacetin, which is an important intermediate in organic synthesis. The infuence of independent variables at 95% confdence level for reac- tions under microwave was evaluated and the molar ratio (acetic acid:glycerol) had a negative efect on acetin production. Finally, the catalysts were characterized after its exposure to conventional and microwave heating and no structural modifcations were observed, which indicates the possibility of catalysts reuse. Keywords Heterogeneous catalysis · Acid activated clays · Glycerol · Acetins · Microwave heating Introduction Large scale production of biodiesel results in the accumulation of glycerol as a co- product and its correct destination in order to avoid harmulf environmental efects is fundamental for the sustainability of industry. Therefore, alternatives for glycerol Electronic supplementary material The online version of this article (https://doi.org/10.1007/s1114 4-019-01594-w) contains supplementary material, which is available to authorized users. * Claudiney Soares Cordeiro claudiney@quimica.ufpr.br 1 Research Center in Applied Chemistry, CEPESQ - Department of Chemistry, Federal University of Paraná, UFPR, P.O. Box 19082, Curitiba, Paraná 81531-980, Brazil