Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 18/2012
ISSN:1211-5541
Abstrakt:
This paper reviews the preparation, physicochemical properties and application
of Mg/Al mixed oxides. Attention is focused on the activity of Mg/Al mixed oxides
in transesterification of rapeseed oil. The mixed oxides were prepared from
hydrotalcites by calcination and were characterized by XRD, FTIR and AAS. The
aim of work was to study the effect of Mg/Al mixed oxides properties such as Mg/Al
mass ratio (2-4), the temperature of calcination (450-1000 °C), time of calcination
(4-17 h) and post-treatment rehydration of mixed oxides on the activity of Mg/Al
catalysts in the transesterification reaction. The results show that the highest
catalytic activity was observed for Mg/Al catalysts with Mg/Al mass ratio of 3,
calcination temperature of 450 °C, time of calcination of 8 hours and rehydration
by water. The leaching of magnesium to liquid phase was also determined and was
always less than 0.1 wt. % — the catalyst was stable.