Biont shell catalyst for biodiesel production.

A novel high performance solid biodiesel catalyst derived from biont shell has been prepared by a tri-step procedure: incomplete carbonization–KF impregnation–activation. The effects of carbonization temperature, concentration of KF solution and activation temperature on the activity of the catalyst were investigated. The activity of the biont shell catalyst was evaluated by transesterification of rapeseed oil with methanol and the mechanism of catalytic activity is discussed. The results indicate that the transesterification yield of rapeseed oil to biodiesel reaches 97.5% with 3 hours reaction and 3 wt% catalyst dosage (based on rapeseed oil mass). The activity of the catalyst for the transesterification came from the active sites formed by reaction of incompletely carbonized biont shell with KF in the procedure of synthesis catalyst. The matrix of the biont catalyst is weakly polar in nature, favoring transesterification of rapeseed oil to biodiesel and hindering the reverse glycerolysis reaction. Therefore, the biont catalyst displayed a higher catalytic activity compared with conventional solid base catalysts tested for biodiesel production.