Continuous production of biodiesel from cottonseed oil and methanol using a column reactor packed with calcined sodium silicate base catalyst

Sodium silicate and that calcined at 400 °C 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 °C, 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 °C, methanol velocity 1 ml·min− 1, oil velocity 3 ml·min− 1, and 5 tower sections). These results indicate that this new continuous biodiesel production process and apparatus present a great potential for industrial application in biodiesel.

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