Biodiesel production from mixed algal and castor oil using a heterogenous biochar catalyst from Citrus limetta peel waste

In the present investigation, the algal and castor oil was mixed at a ratio of 1:1 and used for the production of biodiesel. The biochar catalyst was synthesised from food waste material Citrus limetta peel. The synthesised biochar catalyst was subjected to characterisation using SEM-EDAX, FT-IR, XRD and TGA-DSC analysis. The presence of functional groups was studied using FT-IR. The XRD pattern exhibited a diffraction peak at 2 theta values of 30-40 degrees which indicated the amorphous nature of the catalyst. The TGA analysis results supported the thermal stability of the catalyst at higher temperatures. The highest biodiesel yield of 91% was obtained at a 9:1 molar ratio of methanol to oil, a reaction temperature of 65 degrees C, 4% catalyst concentration, a reaction time of 120 min and an RPM of 500. The produced biodiesel was then characterised using the FT-IR and GC-MS analysis to study the presence of functional groups and fatty acid methyl esters.