Surface‐modified NiFe2O4 nanoparticles for the production of biodiesel from fatty acids and microalgae lipids Dunaliella salina.

Development of a new and sustainable catalyst is necessary to the society for providing economical technology. Surface modification of nanometal oxides is one of the rapidly growing methods for developing a sustainable catalyst with attractive properties than their parent oxide. In this work, surface‐modified nickel ferrites have been carried out using 4,4′‐biphenyldisulfonic acid (BPDSA) as the linker. Thus, obtained modified material has been characterized using different techniques such as DLS, FT‐IR, TGA, XRD, VSM, and XPS. This well‐characterized, stable, robust, recyclable material offers a good conversion in the fatty acid, that is, oleic acid esterification in the presence of methanol in a short period of time (3.0 h). Based on the kinetic study in the oleic acid esterification, it fits in the pseudo first‐order kinetics, and activation energy was found to be 60.0 kJ/mol. Further, the potentiality of our catalyst was also tested in the transesterification of various raw materials like mustard oil, olive oil, almond oil, and neem oil. In addition, it provides an excellent conversion with microalgae lipid extraction for the production of biodiesel. The kinematic viscosity of the methyl oleate (biodiesel) has been found to be 5.0426 mm2/s at 25°C whereas the dynamic viscosity is 6.0511 mPa, which is nearly the same as biodiesel obtained from Dunaliella salina, microalgae lipid. [ABSTRACT FROM AUTHOR]