Optimization of bauhinia variegata biodiesel production and its performance, combustion and emission study on diesel engine

The response surface methodology (RSM) based on central composite design (CCD) was used to optimize various process variables such as methanol to oil molar ratio, reaction time, catalyst concentration (sodium phosphate) and temperature for biodiesel production. The optimum conditions obtained were as follows: 11:1 M ratio of methanol to oil, 45 min reaction time, 2.96 wt% catalyst concentration and 74 degrees C temperature. At these conditions, the obtained bauhinia variegata methyl ester (BVME/biodiesel) yield was 95.1%. Fatty acid composition of oil was categorized by using gas chromatography (GC) analysis. The biodiesel product was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (H-1 NMR and C-13 NMR). The fuel properties of the biodiesel were determined as per ASTM test method. The performance, combustion and emission characteristics of test samples (diesel, biodiesel test blends such as B10, B20, B30, B40 and B100) on a single cylinder diesel engine were studied. The test data were generated by varying the load (0%, 25%, 50%, 75% and 100%). Variations in the engine emissions were recorded using AVL DIGAS 444 analyser. The engine performance was slightly reduced and combustion characteristics had slightly changed when engine was fueled with biodiesel test blends. The CO and HC emissions were less for biodiesel test blends (except B100) but NOx emissions increased with closer engine performance when compared with diesel. (C) 2018 Elsevier Ltd. All rights reserved.