Biodiesel Production from Euglena Sanguinea Using Catalyst Support Extracted From Steel Slag-Optimization and Kinetic Study

Extracting useful materials from the effluents help in cost reduction of catalyst synthesis for transesterification reaction. Hence, in this study, CaO-SiO₂ and MgO–SiO₂ catalysts were prepared in which the nano–silica was extracted from the steel slag. The properties of the slag, extracted nano-silica and synthesized catalysts were characterized in detail. Biodiesel was synthesized from Euglena sanguinea. Optimization of various parameters of transesterification process was done by RSM using CCD. The presence of biodiesel was confirmed with the help of ¹H-NMR, GC–MS and FTIR spectroscopy. The synthesized MgO–SiO₂ and CaO–SiO₂ catalyst possessed a surface area of 31 and 15 m²/g respectively. The optimized parameters obtained using CaO–SiO₂ were methanol to oil ratio of 9:1, catalyst weight % of 5 and duration of 3 h. The optimized parameters of the MgO–SiO₂ catalyst were–methanol to oil ratio of 9:1, catalyst weight % of 6 and reaction time of 5.5 h. The biodiesel yield obtained by using CaO–SiO₂ and MgO–SiO₂ corresponds to 87 and 83. 5% respectively. The loss of yield after reusing 5 times was 20 and 10% for CaO–SiO₂ and MgO–SiO₂ respectively. Kinetic models were compared with respect to their fit with experimental data. Pseudo–first order kinetics was a better fit for the experimental data using MgO–SiO₂. While using CaO–SiO₂ as a catalyst, non-linear kinetic model was found to fit with the experimental data better.

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