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
