Selective Conversion of Glycerol to Lactic Acid by CaO/γ–Al2O3 Supported Catalyst

Selective conversion of glycerol to lactic acid by CaO/MgO and CaO/γ–Al2O3 supported catalysts synthesised with different calcium oxide (CaO) loadings (20 to 50 wt. %) was studied. The catalysts were prepared using impregnation method and calcined at 700°C to be followed by surface analysis to elucidate their surface properties. The activity study was based on selective glycerol conversion to lactic acid at different temperatures (270°C to 330°C) for up to 4 h. The highest yield of lactic acid was recorded by 30 wt. % CaO/γ–Al2O3 catalyst with 95% of glycerol conversion and 49% of lactic acid yield. Effects of reaction conditions such as catalyst loadings (5 to 20 wt. %), reaction temperature (270°C to 330°C), reaction time (0.5 to 4 h) were also demonstrated and correlated with the characteristics of the catalysts. This catalyst could also be reused up to three times with only a slight decrease in its activity.