Experimental investigation on the effects of micro eggshell and nano-eggshell catalysts on biodiesel optimization from waste chicken fat

The chicken eggshell was investigated to synthesis a highly efficient heterogeneous base catalyst to produce chicken oil biodiesel. The micro eggshell catalyst and nano-eggshell catalyst were subjected to various characterization techniques such as XRD, FTIR, SEM, TEM, and BET to study the catalytic performance. The nano-eggshell catalyst showed a high specific surface area of 8.32 m 2 /g, and pore volume of 0.116 cm 3 /g exhibited excellent catalytic performance during transesterification. Response surface methodology based central composite design was adopted to optimize the transesterification reaction parameters. The maximum biodiesel yield of 96.7% was achieved using nano-eggshell catalyst at 1:12 molar ratio, 7.5 wt% catalyst loading, and 2 h reaction time. The R 2 value 0.98 and adjusted R 2 value 0.96 exhibited high correlation between actual and predicted values. Whereas using a micro eggshell catalyst, the maximum biodiesel yield obtained was 94.7%. The physicochemical properties of produced chicken oil biodiesel meet ASTM D 6751 standard.