Production of biodiesel from marine green seaweed using a renewable low-cost heterogeneous catalyst

Abstract

In this study, the biodiesel produced from Ulva lactuca, a marine green seaweed by solid oxide catalyst derived from low-cost waste eggshells is evaluated. Waste eggshells were calcined at 500 °C, 600 °C and 700 °C to increase catalytic activity which was characterized by X-ray diffraction pattern. The peaks of CaO were obtained by calcinations carried out at 700 °C for varied time periods. Comparison of images of scanning electron microscope of calcined eggshells with natural eggshells showed the formation of porous structure with an average pore diameter of 39.17 nm. Biodiesel was prepared by transesterification of algal oil by uncalcined eggshells, calcined eggshells and commercial calcium oxide with methanol. The yield of biodiesel was higher for calcined eggshells (78 %) than uncalcined eggshells (53 %). The produced biodiesel was sampled and analyzed for Gas chromatography – mass spectrometry, which confirmed the presence of predominant alkyl esters like hexadecenoic acid methyl ester, docosanoic methyl ester, palmitic acid methyl ester and oleic acid methyl ester. The heterogeneous catalyst can be reused upto seven times without any prescribed loss of catalyst activity. The Introduction of this eco-friendly catalyst in the transesterification reaction of biodiesel from Ulva lactuca will be cost-reduction for the production of an alternative green fuel.