Approach to Evaluation of Solvent Extraction of Oil from Neem Seed

The effect of agitation and type of impellers and contact time on the solvent extraction of oil from Neem seed was studied in this work. Food grade ethanol was employed as the extraction solvent. 2 2 factorial design optimization technique was applied using Minitab 14 software to investigate the effect of impeller speed and contact time on the percentage yield of oil in agitated solvent extraction of oil from Neem seed. 2 levels for each factor were considered for flat blade turbine impeller (A1) and rushton turbine impeller (A2) at confidence level of 95% (α = .05). The maximum percentage yield was 36.86% and was obtained when impeller type A1 was operated at 84 rpm for 40 minutes contact time at 50 o C extraction temperature and particle size of 0.425 – 0.710mm.The factorial analysis revealed that impeller speed, contact time and their interaction have significant effect on the extraction yield of oil from the Neem seed. The properties of the Neem oil extracted were found to be: specific gravity, 0.9111; pH, 6.5; refractive index, 1.4668; iodine value, 70.21g/g; acid value, 34.33mgKOH/g and Saponification value, 180.95 mgKOH/g. These values compare favourably with literature values.