A novel catalyst prepared from black liquor for biodiesel conversion: An optimization study

This paper reports a new approach for high-value conversion of black liquor into biochar to catalyse the transesterification for biodiesel conversion using waste fry oil (WFO). The central composite design (CCD) and response surface methodology (RSM) were employed to optimize the biodiesel preparation using the catalyst prepared from the paper pulp black liquor precipitated biochar. The transesterification reaction is catalysed by oxidative functional groups (enolic) on the surface of biochar. The effect of alkaline loading in biochar, carbonization temperature, the methanol to oil ratio and the catalyst loading were systematically investigated. The optimal biodiesel conversion conditions were achieved as the following: 27wt% (alkaline loading in biochar), 585 °C (carbonization temperature), 7 (methanol to oil ratio) and 5.5 wt% (catalyst loading), with the biodiesel yield of 95%.