OPTIMIZATION OF BIODIESEL PRODUCTION FROM ORANGE PEEL USING LIMESTONE BASED CALCIUM OXIDE CATALYST VIA IN SITU TRANSESTERIFICATION

Abstract

The rise in population has led to high demand and consumption of petrol-based products thereby causing environmental concerns. In order to reduce the dependency on petrol-diesel, biodiesel has been found to be a suitable alternative. This study was carried out in order to determine the optimum conditions for biodiesel production from orange peel using limestone-based calcium oxide catalyst via in situ transesterification. Pre-treatment and characterization of orange peel was done. X- ray fluorescence (XRF) spectrometry of the limestone sample showed that it contained 55.04% of calcium oxide (CaO). The Fourier Transform-Infra Red (FTIR) analysis of the CaO catalyst revealed the absorption peaks at 3641.6 cm-1, 1394 cm- 1, 872.2 cm-1, and 711.9 cm-1. The specific gravity and the kinematic viscosity of the biodiesel produced was 0.7580 and 0.8 mm2/s respectively. The optimization study was carried out using Design expert version 7.0 for the in situ transesterification experiment. The process parameters considered for the optimization study of the transesterification reaction resulted in an optimum Biodiesel yield of 70.10 % at methanol to oil ratio of 16.5:1, catalyst loading of 2.75 wt.%, reaction temperature and time of 85 oC and 100 minutes respectively. The R2 for the in situ transesterification reaction was estimated to be 0.7015. Quality of biodiesel was successfully produced and it conformed to American Standards and Testing Materials (ASTM D6751).