Production of biodiesel from mixed waste vegetable oil using an aluminium hydrogen sulphate as a heterogeneous acid catalyst

► The manuscript presents the production of biodiesel from mixed waste vegetable oil using an aluminium hydrogen sulphate (Al(HSO4)3) as a heterogeneous acid catalyst. ► Synthesis of catalyst Al(HSO4)3 was carried out. ► In this Al(HSO4)3 as an acid catalyst newly introduced in biodiesel production. In this acid catalyst was easily separated from the product and recycled. The catalyst was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDAX) and acid-base titration method. ► The catalyst deactivation was carried out and it was determined with respect to conversion of triglyceride. ► Parameters optimization for transesterification reaction has been carried out. The biodiesel conversion was analyzed using thermo gravimetric analysis (TGA) and the properties of biodiesel analyzed.