Waste Fish Scale Derived Ferromagnetic Heterogeneous Biocatalyst (Α-Fe2O3-Β-Ca3(PO4)2) for Efficient Transesterification of Waste Silkworm Pupal Lipids into Biodiesel

Abstract

This paper reports an eco-friendly, cost-effective facile route to prepare bio-derived heterogeneous magnetic biocatalysts from the waste fish scale via thermal treatment and used for efficient transesterification to produce biodiesel. The hydroxyapatite of fish scales was impregnated with the varied concentrations (10–30 wt. %) of Fe2+ precursor (FeCl2.4H2O) through the wet impregnation method and transformed into α-Fe2O3-β-TCP via calcination at 700–1000 °C. The transformation of hydroxyapatite to β-Ca3(PO4)2 impregnated with α-Fe2O3 confirmed through XRD and Raman analysis. The FTIR spectra of the prepared sample α-Fe2O3-β-TCP support its structural and chemical composition. The SEM images confirm the presence of α-Fe2O3 in the waste fish scales derived catalysts. The magnetic studies revealed the soft ferromagnetic behavior for the optimized catalysts Fe-FSC-30 with saturation magnetization 0.59 emu/g at 300 K. The magnetic fish scale catalysts was used for the transesterification of silkworm pupa lipids. The FTIR and 1H-NMR spectroscopy recognized the conversion of silkworm pupa lipids into biodiesel. The transesterification efficiency of heterogeneous magnetic biocatalysts is estimated to be ~90 % via 1H-NMR. The GC-MS identified the presence of the main constituents of SPL-biodiesel. The study demonstrated waste fish scale-derived low-cost magnetic catalysts for efficient transesterification of lipids for biodiesel production.