Biodiesel production from preutilized cooking oil using a renewable heterogeneous eggshell‐coconut pith catalyst: Process optimization and characterization

Abstract

AbstractThis research article deals with the synthesis of a heterogeneous eggshell‐coconut pith catalyst for the transesterification of preutilized cooking oil into a biodiesel fuel. A wet impregnation technique was adopted to prepare the heterogenous catalyst from calcined eggshells and activated coconut pith, followed by the surface analysis for pores using the scanning electron microscopy. The synthesized catalyst was employed for the transesterification of preutilized or waste cooking oil for its conversion into fatty acid methyl esters. Response surface methodology (RSM) using a four factor, three level, central composite design (CCD) was used to investigate the effect of the process parameters (alcohol:oil ratio [4:1,6:1,8:1], temperature [30°C, 50°C, and 70°C], time [60, 120, and 180 min], and ESCP‐catalyst dosage [1, 5, and 9 wt.%]) on the response variable, biodiesel yield. The biodiesel yield from preutilized cooking oil was found to be 72% at the optimized process conditions (50°C, 8:1 methanol to oil molar ratio, 5 wt.% ESCP‐catalyst, reaction time of 60 min). The GC‐MS analysis of biodiesel produced showed peaks relevant to conventional diesel. The study has resulted in the synthesis of a stable, cost effective, highly active catalyst for the preutilized cooking oil transesterification into biodiesel.