Production of bio-oil from algal biomass and its upgradation to biodiesel using CaO-based heterogeneous catalysts

The present article deals with the production of bio-oil from algal biomass as well as the preparation and characterization of noble CaO-based heterogeneous catalyst for upgradation of bio-oil to biodiesel. The bio-oil has been extracted from algal biomass using hexane as solvent in soxhlet apparatus and upgraded to biodiesel by transesterification using noble CaO-based heterogeneous catalysts. Catalyst with TiO₂:CaO molar ratio of 0.25 and calcination temperature of 700°C has been found to be most suitable among all the catalysts developed. Characterization of the catalysts has been done by using X-ray diffraction (XRD), scanning electron microscope (SEM), and thermo-gravimetric analysis (TGA). The input--output model has been developed to correlate experimental and predicted value of biodiesel yield. Optimization of process parameters has been done using response surface methodology. Various properties and elemental composition of algal bio-oil and biodiesel have been determined and compared with biodiesel.