Microwave-irradiated acetylation of glycerol catalyzed by acid activated clays
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In this study, the investigation of the effects related to glycerol and acetic acid esterification over solid acid catalysts under microwave radiation by full factorial design 23 is described. Using clay minerals activated with H3PO4 as catalysts it was possible 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 influence of independent variables at 95% confidence level for reactions under microwave was evaluated and the molar ratio (acetic acid:glycerol) had a negative effect on acetin production. Finally, the catalysts were characterized after its exposure to conventional and microwave heating and no structural modifications were observed, which indicates the possibility of catalysts reuse.
KeywordsHeterogeneous catalysis Acid activated clays Glycerol Acetins Microwave heating
The authors are grateful to the following Brazilian funding agencies for financial support: CNPq, CAPES and FINEP.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- 13.Dill LP, Kochepka DM, Krieger N, Ramos LP (2018) Biocatal Biotransform 1:1–10Google Scholar
- 18.American Oil Chemists’ Society (AOCS) (1997) free fatty acids. In: Official method sampling and analysis of commercial fats and oils, 5th edn. AOCS: Urbana, ILGoogle Scholar
- 19.National Agency for Petroleum, Natural Gas and Biofuels (ANP), Ministry of Mines and Energy (2014) Resolution Number 45; ANP: Brasília, Distrito Federal, Brazil, Aug 25. 2014; http://nxt.anp.gov.br/NXT/gateway.dll/leg/resolucoes_anp/2014/agosto/ranp%2045%20-%202014.xml?fn=document-frameset.htm$f=templates$3.0. Accessed 22 May 2018
- 26.Komadel P, Madejova J (2006) Developments in clay science. In: Bergaya Faïza, Theng BKG, Lagaly G (eds) Handbook of clay science, 1st edn. Elsevier, AmsterdamGoogle Scholar
- 29.Harun FW, Almadani EA, Radzi SM (2016) J Sci Res Dev 3:90–96Google Scholar
- 30.Sigma-Aldrich (2018). https://www.sigmaaldrich.com/brazil.html. Accessed 13 July 2018