Marigold ( Tagetes ) petals as a novel green bio-based heterogeneous catalyst for biodiesel production from palm oil

Heterogeneous catalysts have an edge over homogeneous catalysts for the production of biodiesel due to limitations like nonrenewable nature, reusability, separation, saponification, equipment corrosion, and washing. The potential of marigold petals as an excellent bio-based catalyst was derived and utilized in the present study to produce sustainable palm oil methyl ester. The dried marigold petals are burned to produce ash, then calcined (800°C, 2 h) to prepare the catalyst. SEM, EDX, XRD, FTIR, TGA, and BET characterized the prepared calcined catalyst. The reported catalyst consists of a high percentage of potassium oxide and calcium oxide with a basic strength within 12.1