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

Abstract

ABSTRACT 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<H_<18.4, and a surface area of 7.095 m2/g. The catalyst efficiency has shown effective conversion of palm oil into biodiesel with 96% yield under the optimum condition of 10:1 methanol to oil ratio, 6 wt.% catalysts, and temperature of 65°C in 180 min reaction time. GC-MS and 1H NMR methods verified the biodiesel. The obtained biodiesel meets the ASTM standards. The catalyst was utilized for four cycles without a significant decline in activity. The study revealed the potentiality of the novel green solid catalyst from marigold petals for biodiesel production with the capability to minimize overall production expenses.