Cost-Effective Biodiesel Synthesis from Waste Marble Powder as A Green Heterogeneous Catalyst Using Pongamia Pinnata Oil

Abstract

Waste marble powder (WMP) is Investigated for developing heterogeneous catalysts by calcination method and used in biodiesel synthesis by esterification-transesterification process from Pongamia Pinnata oil. Hammet indicators, Fourier transform infrared (FT-IR), Thermogravimetric analysis, and X-ray powder diffraction (XRD) techniques were also studied for the characterization of developed catalyst from waste marble powder (WMP). The conversion of calcium carbonate to calcium oxide in marble powder was found at 800°C after calcination. The maximum biodiesel yield reached about 94% using a 3.5 wt% catalyst, 9:1 methanol to Pongamia pinnata oil molar ratio, and 2.5 hour process time at 65°C. The biodiesel purity was tested by gas chromatography analysis. The catalyst stability was tested by recyclability test and found a small decrease in biodiesel yield up to 5 recyclability runs. The solid heterogeneous catalyst from WMP proves that the harmful waste could be converted and used as an economically efficient solid heterogeneous catalyst for sustainable biodiesel production from Pongamia Pinnata oil.