Sustainable Synthesis of a Waste-Derived Calcium Metal–Organic Framework from PET Plastic and Phosphate Mine Waste for Efficient Biodiesel Production
Khaireddin Boukayouht, Zouhir Balagh, Said Sair, Othmane Amadine, Yassine Taha, Yassine Ait-khouia, Samir El HankariAbstract
This study presents a sustainable strategy for the synthesis of a calcium based metal–organic framework (Ca-MOF) using phosphate mine waste rocks and polyethylene terephthalate (PET) plastic waste as alternative calcium and ligand sources, respectively. The Ca-MOF was synthesized in water under mild conditions through a simple and environmentally friendly process, achieving a high space-time yield of 790 kg·m–3·day–1. Structural and textural characterization confirmed the successful formation of a mesoporous and highly crystalline material. The waste-derived Ca-MOF was successfully applied as a heterogeneous catalyst for biodiesel production via transesterification of rapeseed oil, reaching a conversion yield of 98% under the optimized conditions (3 wt % catalyst, oil/methanol ratio of 8, 165 min, and 70 °C). In addition, the catalyst exhibited good stability and reusability over six consecutive cycles. This work demonstrates the potential of waste-derived MOFs as sustainable and efficient catalysts for renewable fuel production.