Optimizing production of biodiesel catalysed by chemically tuned natural zeolites

Abstract

The twin crises of fossil fuel depletion and environmental degradation coupled with their unpredictable prices is a reality. Biodiesel is a promising, viable and environmentally friendly alternative. However, production of biodiesel from agro-based oils has challenges such as high cost of catalysts. The use of heterogeneous catalysts such as zeolites is more promising. Synthetic and natural zeolites are potentially viable catalysts though the latter belongs to less effective class of zeolites. Here, an environmentally sustainable, cheaper and easily available alternative natural zeolite from Kenya (NZK) is presented. Cation exchange into the zeolite improves its catalysis. The NZK was characterized by scanning electron microscope, X-ray diffraction and infrared spectroscopy as belonging to clinoptilolite type. The iodine value, viscosity, cloud point, specific density and acid value were among parameters used to identify the biodiesel produced. A successful optimization order of Na-NZK>Cu-NZK>Pb–NZK in transesterification of Jatropha curcas oil to biodiesel was obtained.