Insight into the catalytic transformation of the waste products of some edible oils (corn oil and palm oil) into biodiesel using MgO/clinoptilolite green nanocomposite

[Display omitted] •MgO/clinoptilolite green nanocomposite was prepared as an environmental catalyst.•The catalyst is of enhanced surface area, surface reactivity, and total basicity.•It was applied in the transesterification of corn oil (94 %) and palm oil (97 %).•Technically, the produced biodiesel samples match the international specifications.•It is of strong recyclability and better activity than several studied catalysts. The urgent demand for renewable, eco-friendly and safe energy resources rather than traditional fossil fuels is the most critical issue encountering in the contemporary world. The urgent demand for renewable, eco-friendly and safe energy resources rather than traditional fossil fuels is the most critical issue encountering in the contemporary world. Clinoptilolite decorated with nano MgO (MgO/CP) was synthesized as advanced hybrid structure by alkali green modification process using green tea extract. It showed significant enhancement in the surface area (324.5 m2/g), ion exchange capacity (141.5 meq/100 g), and the total basicity (4.34 mmol OH/g) which qualifies the composite as a potential basic catalyst in the transesterification reactions. The MgO/CP catalyst was applied in the transesterification of used corn oil and palm oil. The composite is of promising activity and achieved biodiesel yield of 94 % from corn oil after 120 min using 4 wt., % of it as catalyst load and 15:1 as methanol-to-oil ratio at 60 °C and stirring speed of 1250 rpm. For palm oil, the catalyst achieved a yield of 97.6 % after 150 min using 4 wt., % of it as catalyst load and 20:1 as methanol-to-oil ratio at 70 °C and stirring speed of 1250 rpm. The recyclability properties of MgO/CP green nanocomposite as basic catalyst validated significant reusing of it in the transesterification of both corn oil and palm oil with high yields. The extracted biodiesel from corn oil and palm oil matches strongly the recommended limitations by ASTM D-6751 and EN 14214 standards.