A Novel Biomass-Based Catalyst Composite Using Waste Chicken Eggshells and Avocado Seeds for Biolubricant Production:...

Area of Science:

• Green Chemistry
• Catalysis
• Biomaterials

Background:

• The demand for sustainable biolubricants is increasing, driving research into eco-friendly production methods.
• Petrochemical-based lubricants pose environmental concerns, necessitating alternatives.
• Biomass-derived catalysts offer a promising route for sustainable chemical synthesis.

Purpose of the Study:

• To develop and optimize a novel biomass-based composite catalyst for producing trimethylolpropane fatty acid triester (TFATE) biolubricant.
• To investigate the catalytic performance and reaction kinetics of the prepared catalyst in the transesterification of fatty acid methyl esters (FAMEs).
• To evaluate the catalyst's reusability and identify factors affecting its deactivation.

Main Methods:

• A novel catalyst was synthesized from avocado seed and chicken eggshell residues, with calcium oxide (CaO) impregnation.
• Taguchi experimental design was employed to optimize catalyst preparation conditions (impregnation time/temperature, CaO/char ratio, activation temperature).
• Transesterification reactions were conducted using the optimized catalyst to produce TFATE, with reaction kinetics studied at 120 and 150 °C.

Main Results:

• The optimized catalyst achieved 90% TFATE formation under specific reaction conditions.
• The transesterification reaction was characterized as endothermic with kinetic rate constants ranging from 7.45 × 10^-3 to 10.31 × 10^-3 L/mmol·min and an activation energy of 15 kJ/mol.
• Catalyst characterization confirmed the importance of crystalline structure and CaO loading for catalytic activity, while ¹H NMR verified TFATE formation. Catalyst deactivation was attributed to active-site poisoning with minimal calcium leaching.

Conclusions:

• A cost-effective, biomass-derived catalyst was successfully developed for sustainable biolubricant production.
• The catalyst demonstrates high efficiency in TFATE synthesis, offering a viable alternative to petrochemical lubricants.
• Understanding catalyst deactivation mechanisms is crucial for improving long-term performance and reusability in industrial applications.