Radish (Raphanus sativus L.) leaves: A novel source for a highly efficient heterogeneous base catalyst for biodiesel production using waste soybean cooking oil and Scenedesmus obliquus oil

In this study, a novel heterogeneous catalyst from the unexploited radish leaves (Raphanus sativus L.) was synthesized and employed for biodiesel production using waste soybean cooking oil (SWCO) and Scenedesmus obliquus oil (OSO). The synthesized catalyst (CLP) was characterized by FTIR, BET, XRD, TGA, SEM, TEM, EDX, BET, and XPS. Moreover, the Hammett indicator test and CO2-TPD were used to assess the derived catalyst's basicity. The results reported the presence of Ca, S, Si, Cl, Al, P, Mg, Mn, Na, and a high percentage of potassium (57.30 wt%) in the form of carbonates and oxides. The maximum SWCO and OSO conversion of 98.0% and 91.32% were obtained using 6 wt% and 5 wt% catalyst loading and 12:1, 16:1 methanol to oil molar ratio for 150 and 90 min at 60 degrees C, respectively. The CLP exhibits excellent recyclability, achieving 90.57% oil conversion after four successive cycles. The fuel properties of the produced biodiesel were compatible with international standards. The synthesized catalyst is highly efficient, cheap, renewable, green, and can help reduce biodiesel production costs. Thus, the CLP catalyst might be a promising candidate for large-scale biodiesel production with a competitive price. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

A novel catalyst synthesized from unexploited radish leaves was used for biodiesel production. The catalyst exhibited excellent catalytic performance and recyclability, and the produced biodiesel met international standards for fuel properties.