Novel solventless green synthesis of biodiesel via acid catalyzed transesterification of palm kernel oil with cellobiose

Abstract

The combustion of fossil fuels and the attendant extreme weather events continue to exacerbate greenhouse gas emissions and global warming, prompting increased demand for environmentally benign and green renewable energy alternatives. Biodiesel derived from cellulosic biomass represents one such promising alternative. Traditional biodiesel synthesis is constrained by dependence on toxic methanol and the high costs associated with raw materials and catalysts. In this study, a novel solventless green synthesis of biodiesel was achieved through acid catalyzed transesterification of palm kernel oil (PKO) with laboratory synthesized cellobiose. The reaction was carried out by dissolving 0.6 g of cellobiose in 1 mL of concentrated HCl, mixing the solution with 100 mL of PKO, and refluxing at 115 °C for 6 hours at 800 rpm. Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF MS) confirmed the presence of cellobiose through potassium adduct peaks at m/z values of 379.169, 380.182, and 381.189. Fourier Transform Infrared (FTIR) analysis of the biodiesel product revealed absorption bands at 1465 and 1163 cm−1 , confirming the conversion of palm kernel oil to biodiesel. Gas Chromatography Mass Spectrometry (GC MS) analysis established that the biodiesel comprised predominantly fatty acid ethyl esters (57.38%) and fatty acid methyl esters (22.17%), with an overall yield of 96.75%. The physicochemical characterization results fell within conventional limits for biodiesel properties, yielding a flash point of 144 °C, a pour point of −11 °C, and a kinematic viscosity of 2.02 mm2/s, thereby confirming fuel viability.