EMPIRICAL COMPARISONS AND CORRELATIONS BETWEEN CETANE NUMBER AND PHYSICOCHEMICAL PROPERTIES OF BIODIESEL FUELS

Abstract

CO2 emissions due to transportation have been increasing since records have been kept, only in recent years there has been a 6 % increase in CO2 emissions from 2015 to 2019. So, it is a sector in constant increase and where there is much work to do to reduce emissions of this global warming precursor gas. Comparatively, carbon dioxide (CO2) emissions from biodiesel, obtained from rapeseed oil, with respect to diesel are significantly reduced. In the same sense, and adding an economic component, biodiesel produced from raw materials such as olive oil, olive pomace oil, sunflower oil, soybean seed oil, algae, castor or castor oil, rapeseed, palm, corn, Brassica carinata or Ethiopian rapeseed, and sea buckthorn, shows that it is more competitive in terms of price and environmental protection. An additional advantage of biodiesel over conventional diesel, thanks to its vegetable origin, is that it lacks cyclic chain hydrocarbons and aromatics, so its use in combustion does not produce carbonaceous residues, furans or dioxins. In addition, they produce less CO emissions due to the greater amount of oxygen in biodiesel and SO2 emissions are almost negligible. On the other hand, their combustion in both small and large engines gives somewhat lower power than with conventional diesel. In this work, analyses of the different properties of biodiesel produced by a total of 24 types of raw material, including blends between them, have been carried out. The main properties of the product have been characterized and found. One of the most remarkable results is that the increase in the cetane number of the samples implies a uniform increase or decrease in the rest of the properties. No significant differences were found between the properties of biodiesel from frying oil residues and those of un-fried or fresh oils, and even those of diesel. Keywords: biofuels, biodiesel,wastes, sustainable, development, correlations, cetane number, cetane index