Application of converter slag as an effective and low-cost solid base catalyst for the transesterification process

Abstract

ABSTRACT Calcium oxide is a suitable and valuable catalyst for producing biodiesel. In this research, the feasibility of producing biodiesel from waste frying oil with a new environmentally friendly and low cost heterogeneous solid-base catalyst from waste slag was evaluated. The composition, texture, structure, and chemical characteristics of the converter slag were examined by thermogravimetric analysis (TGA), X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET), Field Emission Scanning Electron Microscopy (FE-SEM), and X-ray diffraction (XRD). Moreover, the catalyst reusability, reaction conditions, and the effects of catalyst preparation conditions were studied in this experiment. The converter slag was calcined at 1100°C for 8 hours. Gas chromatography (GC) was used to analyse and evaluate the produced biodiesel. The biodiesel characteristics were compared with the ASTM D 6751 standard. It was found that the maximum efficiency of using converter slag for producing biodiesel was 77.8 ± 1.5% under the reaction time 6 hours, catalyst amount 10 wt.%, and reaction conditions of methanol to oil molar ratio 15:1. The converter slag as a catalyst was recovered and reused for three cycles. This study demonstrated how a low-cost catalyst could be used in the production of a value-added product (i.e. biodiesel) from waste oil.