This study is initiated to develop a composite catalyst from naturally occurring and waste
materials. The catalyst preparation conditions which include activation temperature (600-1000
o
C),
activation time (2-4 h) and mixing proportion of anthill to eggshell (1:1.5-1:4) were investigated using
central composite design (CCD) of response surface methodology (RSM) in design expert software.
A model that correlates the three process parameters to the response (biodiesel yield) was established.
The model reliability was evaluated using analysis of variance (ANOVA). The catalyst prepared
under the optimum conditions was characterized using scanning electron microscopy (SEM), Fourier
transform infrared radiation (FTIR) spectroscopy and X-ray Diffraction (XRD) technique. From the
ANOVA, both the predicted and experimental biodiesel yields agreed well with each other with
correlation coefficient (R
2)
of 0.9806. The optimum composite anthill-eggshell catalyst preparation
conditions were obtained as follow, activation temperature of 1000
o
C, 4 h activation time and anthill/
eggshell mixing ratio of 1:4, which provided biodiesel yield of 70.92
