Optimization and Evaluation of Compression Ignition Engine Fuel Property of Neem Biodiesel

Umeuzuegbu J.C.

Characterization, NSOFAME, optimization, synthesis, transesterification

The universal increasing energy demand as a result of increase in population and high spate of industrialization coupled with the fast depletion of fossil fuel has resulted in the search of alternative energy sources to replace fossil fuel. This research work is therefore focused on optimization and evaluation of compression ignition engine fuel properties of neem seed oil fatty acid methyl ester (NSOFAME). The neem seed oil (NSO) was extracted using solvent extraction method. The oil was characterized based on American Society for Testing and Materials (ASTM) method. The fatty acid profile of the neem seed oil was determined using gas chromatography mass spectrometry while the functional group of the oil was analyzed using Fourier transform infrared spectroscopy. The effect of process parameter on the yield of NSOFAME was investigated using one factor at a time method. The NSO was pretreated to reduce the free fatty acid below 1% and then tranesterified using methanol in the presence of sodium hydroxide, (NaOH) catalyst. The fuel properties of the NSOFAME produced was determined based on ASTM standards. The physiochemical properties of NSO , density, saponification value, iodine value, peroxide value, kinematic viscosity, fire point, flash point cloud point, pour point, refractive index, specific gravity, moisture content, acid value, free fatty acid, and calorific value gave the values 984Kg/m³, 21omgKOH/g, 64.88gI₂/100goil, 6meq/Kg , 64.06mm²/s, ⁰C, ⁰C, ⁰C, ⁰C, 1.4662, 0.984, 0.25%, 4.40mgKOH/g 2.20% and 29.79MJ/Kg respectively. The fatty acid profile of NSO is evenly distribution with saturated and unsaturated acids suitable for biodiesel production. The process parameters , catalyst concentration, reaction temperature, ,methanol to oil molar ratio, reaction time and agitation speed greatly affected the biodiesel yield as their increase resulted in the increase of biodiesel yield until the optimum parameter was reached when the yield started decreasing. The experimentally determined properties of the NSOFAME; acid value, density, kinematic viscosity, fire point, flash point, cetane number, refractive index, specific gravity, calorific value, iodine value, cloud point and pour point gave the values, 0.420, 870Kg/m³, 4.92mm²s-1, 163⁰C, 160⁰C, 60.58, 1.4462, 0.870, 38.06MJ/Kg, 70.2I₂g/100g, 5⁰C, 3⁰C respectively. The optimum conditions suggested by the result analysis for maximum FAME yield of 86% within the ranges studied were: methanol to oil molar ratio 8:1, catalyst concentration 0.9%wt, reaction temperature of 65⁰C, reaction time of 60 minutes and agitation speed 300 rpm. Actual experiment based on the optimum conditions produced 88% yield of FAME.