Efficient catalytic production of biodiesel using nano-sized sugar beet agro-industrial waste

[Display omitted] •Costless CaO-rich agro-industrial waste was used for catalytic biodiesel production.•Thermal treatment affects the catalytic performance of the proposed catalyst.•Biodiesel conversion of 93% is obtained by 1 wt% catalyst, methanol/oil = 4.5:1 at 75 °C for 60 min.•The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue. This paper addresses the use of agro-industrial residue as a promising heterogeneous catalyst for the efficient production of biodiesel. That is, CaO-rich sugarbeet agro-industrial waste (smashed down to nano-size) shows superb catalytic activity for biodiesel production via transesterification process employing sunflower oil and methanol. Physicochemical properties of the proposed catalyst are probed by TGA–DTG, XRF, XRD, FT-IR, SEM, BET, and CO2-TPD techniques. Biodiesel conversion (%) of Ca. 93% is achieved under the optimal conditions (catalyst loading of 1 wt%, methanol/oil molar ratio of 4.5:1, refluxed at 75 °C for 60 min). The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue which imparts its economic feasibility. Also, the proposed CaO-rich residue can be reused twice while retaining its catalytic activity. The thus-produced biodiesel fuel compiles the ASTM D6751 and EN-14214 specifications.