Sodium silicate and that calcined at 400℃ for 2 h were used to catalyze the transesterification of cottonseed oil with methanol. Calcined sodium silicate (CSS) catalyst exhibited much higher catalytic activity and stability. A maximum biodiesel yield of 98.9% was achieved at methanol/oil mole ratio of 12:1

reaction temperature 65℃

reaction time 3.0 h

and CSS/oil mass ratio of 2 wt%. After 7 consecutive reactions without any treatment

biodiesel yield reduced to 82.5%. Considering technological and economic feasibility

CSS base catalyst supported on θ rings was prepared for continuous transesterification. The maximum yield was 99.1% under optimum conditions (reaction temperature 55℃

methanol velocity 1 ml·min

-1

oil velocity 3ml·min

-1

and 5 tower sections). These results indicate that this newcontinuous biodiesel production process and apparatus present a great potential for industrial application in biodiesel.