Vol.:(0123456789) Reaction Kinetics, Mechanisms and Catalysis (2021) 132:203–218 https://doi.org/10.1007/s11144-020-01915-4 1 3 Rape oil transesterifcation by methanol and ethanol on extruded hydrotalcite catalyst Aleš Kašpárek 1  · Jaroslav Kocík 1  · Věnceslava Tokarová 1 Received: 16 November 2020 / Accepted: 8 December 2020 / Published online: 27 January 2021 © Akadémiai Kiadó, Budapest, Hungary 2021 Abstract This article is devoted to rape oil transesterifcation by methanol and ethanol on powder and extruded Mg/Al hydrotalcite catalyst in a stirred reactor under atmos- pheric pressure close to boiling point of alcohol with inserted perforated basket with extrudates. With 15 wt% of catalyst in relation to rape oil and molar ratio methanol/ ester group of oil 13:1, the yield of monomethylester reached 99.5% within 48 h in the case of fresh catalyst. After recalcination, the same catalyst enabled the same yield of monomethylester within 72 h and third cycle of this catalyst after two recal- cinations led to 98.5% of monomethylester yield also within 72 h. Extrudates ena- bled the same monoester yield as hydrotalcite powder within 24 (60–61%) up to 48 h (99%). Moreover, several experiments were done in the autoclave to assume temperature efect to reaction time. Enhanced temperature 140 °C provided nearly 99% monoester yield within 12 h. A new arrangement with extrudates in a perfo- rated basket makes transesterifcation with heterogeneous hydrotalcite catalyst easily feasible. Diferently from rather promising results in rape oil transesterifcation with methanol, ethanol worked in this reaction much more slowly. Not surprisingly water inhibits transesterifcation, as the reaction with 96% ethanol shows. Using 99.8% ethanol nearly without water makes transesterifcation signifcantly faster, but 51% monoester yield after 120 h reaction time is still insufcient. Nevertheless, ethanol remains a promising raw material for oil transesterifcation, as it can be prepared by a bioprocess, which makes the whole technology based on renewable sources. Keywords Fatty acid ester · Rape oil · Heterogeneous catalysis · Hydrotalcite * Aleš Kašpárek ales.kasparek@unicre.cz 1 Unipetrol Centre for Research and Education, Revoluční 1521/84, 400 01 Ústí nad Labem, Czech Republic