Active biocatalyst for biodiesel production from spent coffee ground

Area of Science:

• Biocatalysis and Nanotechnology
• Sustainable Chemistry

Background:

• Lipase immobilization is crucial for enzyme reusability and efficient biofuel production.
• Developing stable and active immobilized enzymes on magnetic nanoparticles offers advantages in separation and recovery.

Purpose of the Study:

• To immobilize lipase from Thermomyces lanuginosus onto citric acid-modified Fe3O4/Au magnetic nanoparticles.
• To evaluate the performance of the immobilized lipase in biodiesel production from spent coffee grounds in a solvent-free system.

Main Methods:

• Physical adsorption was employed for lipase immobilization on citric acid-modified Fe3O4/Au magnetic nanoparticles.
• Ligand exchange method was optimized for high enzyme loading and stability.
• Biodiesel production was conducted in a solvent-free system using spent coffee grounds as feedstock.

Main Results:

• The immobilized lipase retained over 90% of its initial activity after 60 days.
• Biodiesel yield reached approximately 100% after 24 hours, demonstrating fast enzymatic kinetics.
• The immobilized lipase showed no significant activity decrease over the first three reuse cycles.
• The produced biodiesel met EN14214 standards with an ester content of 98.4% and an iodine value of 76.67 g/100g.

Conclusions:

• Citric acid-modified Fe3O4/Au magnetic nanoparticles provide an effective support for lipase immobilization, preserving activity and enabling reusability.
• The solvent-free biodiesel production process using immobilized lipase is highly efficient and sustainable.
• The immobilized enzyme system demonstrates excellent stability and catalytic performance, making it suitable for industrial applications.