Thermal modification of chicken eggshell as heterogeneous catalyst for palm kernel biodiesel production in an optimization process

Abstract

Synthesis of the heterogeneous chicken eggshell catalyst (CEC) using thermal treatment at temperatures of 800 °C (CEC800) and 900 °C (CEC900) for palm kernel biodiesel (PBD) production was undertaken. The morphology, chemical composition, and surface area of the catalysts were determined. Catalyst’s efficiency in the production of biodiesel from palm kernel oil was studied using a definitive screening design of optimization technique. The optimization parameters investigated were calcination temperature, catalyst quantity, methanol:oil molar ratio, and reaction time. The stability of the catalyst after the 5th cycle of repeated usage was studied. The CEC900 contained the highest chemical composition of 32.36% (wt) calcium with the morphology of highly porous, uniformly distributed spherical shape, with no agglomeration. A surface area of 120.4 m2/g and a smaller pore size of 1.324 nm were obtained from the CEC900. The optimal operating parameters of 4% (w/w) catalyst quantity, 10:1 methanol:oil molar ratio, 50 °C reaction temperature, 1 h reaction time, and 900 °C calcination temperature were obtained to yield optimum biodiesel of 97.10%. Qualitative characterization confirmed that the CEC900 is suitable to produce quality PBD of ASTM standard. Reduction in the catalytic activity of 6% PBD was noticed in the 5th cycle. Therefore, thermal-modified CEC is a suitable and low-cost catalyst for biodiesel production.