PRODUCTION, OPTIMIZATION AND CHARACTERIZATION OF BIODISEL FROM MIXED CASTOR AND JATRoPHA SEED OILS

Abstract

Biodiesel is a renewable and sustainable alternative energy source with a great potential to substitute conventional fossil fuel with less environmental impact. Vegetable oils which are edible or non-edible, animal fats and waste cooking oils, algal oils either in pure or mixed at different ratios can be used as feed stock for biodiesel production. Selection of feedstock should be systematic and done based up on full life time analysis. Blending of the feedstock should be technical to obtain the best yield and beater economic advantage. Non edible oils are getting more interest for biodiesel production due to their comparative advantage they have, castor seed oil and jatropha seed oil are among the non-edible oils with great potential for the biodiesel production. This study aimed with the production, optimization and characterization of biodiesel from mixed feed stocks of castor seed and jatropha seed oils through transesterification with methanol by using KOH as alkaline catalyst. The oils from the seeds were extracted by Soxhlet using n-hexane as solvent. During extraction oil yield of 34% and 52% was achieved from castor and jatropha seeds respectively. The extracted oils were mixed at different volumetric ratios and their physical and chemical properties were determined in compliance with American society for testing materials (ASTM) and most of the parameters were in agreement with in the ASTM standards. Methanol to oil molar ratio, Castor to jatropha oil volumetric ratio, catalyst concentration were the processes variables selected to investigate their effect on the response which is the biodiesel yield while reaction temperature, mixing intensity, and reaction time were set at optimum values, CCD with three factors and five levels was used to conduct the experiment and design expert software,Response surface methodology (RSM) were used to investigate the individual and the interaction effects of the process variables on biodiesel yield. The optimum yield of biodiesel obtained was at methanol to oil molar ratio of 4, catalyst concentration 0.5%(wt/wt) and at castor to jatropha oil (MCJSO) volume ratio 25:75 which is (which is 1:3) and the optimal biodiesel yield was 91%. The physicochemical properties of the biodiesel were density of 880 kg/m3 , Kinematic viscosity 2.2 mm 2 /s,the acid value 0.561 mg KOH/g oil, the saponification value 230 mg of KOH/g oil, water content 0.027% heating value was 41.42MJ/kg, and most of the obtained values are within the ASTM standards