MgCoAl–LDH derived heterogeneous catalysts for the ethanol transesterification of canola oil to biodiesel

Mixed oxide catalysts derived from Mg–Co–Al–La layered double hydroxide (LDH) with various Mg:Co:Al:La ratios were prepared by co-precipitation and calcination. Their catalytic performance as heterogeneous base catalysts for the transesterification of canola oil with ethanol to produce biodiesel was compared over 5 h in a batch reactor at 473 K. Amending the catalyst by the addition of La, a possible stabilizer and catalyst, and an increase in Mg, which provides the main base catalyst sites, did not seem to affect the catalytic activity. Experiments using Mg2CoAl catalyst are reported, showing the effects of reaction temperature, ethanol-to-oil molar ratio, particle size, and catalyst stability in the transesterification of canola oil. The catalytic activity of the Mg2CoAl was demonstrated and shown to be stable and reusable maintaining its activity after 7 cycles. The kinetics of the transesterification of canola oil catalyzed by Mg2CoAl may be modeled as a first-order reaction.