In this work, statistical modeling and
optimization of biodiesel production from Azadirachta
Indica(neem) using co-solvent technique via a two-step
transesterification process was carried out. Neem oil was
extracted from neem seeds and properties such as moisture
content, specific gravity, acid value, saponification value
and iodine value were determined. The experimental design
used was Central Composite Design. The range of factor
levels used for the Central Composite Design were reaction
temperature (30°C to 46°C), catalyst amount (0.8% to
1.2%, w/w), reaction time (20 to 40min) and methanol-tooil molar ratio (5:1 to 9:1). The co-solvents used were
methanol and diethyl ether. The co-solvent-to-methanol
volume ratio for all the experimental runs was kept constant
at 1:1. Also the biodiesel produced was characterized for
some important properties including acid value, specific
gravity, saponification value, iodine value, cetane number,
ester value, kinematic viscosity, flash point, pour point and
cloud point. Optimized biodiesel yield of 84.77% was
obtained for reaction time of 35 min, catalyst amount of
1.10g, reaction temperature of 34°C, and oil-to-methanol
molar ratio of 6:1. The cetane number (51.733), specific
gravity (0.8881g/cm3), flash point (134oC) and kinematic
viscosity (5.86mm2/s) of the produced biodiesel met the
ASTM specifications. The results of characterization of the
biodiesel revealed that biodiesel can be produced at lower
reaction conditions and with comparable fuel property with
biodiesel produced using conventional methods.