Relating the cetane number of biodiesel fuels to their fatty acid composition: A critical study

Abstract

The cetane number is one of the most significant properties to specify the ignition quality of a fuel for use in a diesel engine. The cetane number of biodiesel fuels is considerably influenced by their fatty acid methyl ester composition. The determination of cetane number of biodiesel is an expensive and time-consuming process. The objective of the present work is to predict the cetane numbers of different biodiesels using their fatty acid ester composition. Fifteen different biodiesel (including three blends) fuels were prepared and their cetane numbers were experimentally measured. An extensive literature review was made and the measured cetane numbers were compared with the reported values. To predict the cetane numbers of biodiesel fuels from their fatty acid methyl ester composition, a multiple linear regression model was developed. The cetane numbers and fatty acid compositions of 57 biodiesel fuels and 7 pure fatty acid methyl esters from the available literature were given as inputs. The experimentally measured cetane numbers and fatty acid compositions of four biodiesel fuels were also given as inputs to develop the regression model. The regression model has yielded an R 2 value of 0.953 and a standard deviation of 2.271. The predicted cetane numbers are comparable with the experimentally measured cetane numbers. The maximum prediction error from the present model was found to be 8 per cent. Similarly, the present model was compared with the available litrature models. The maximum prediction error from the literature models was found to be 15 per cent. The present model also shows a good agreement with the measured cetane numbers.

Microalgal Species Selection for Biodiesel Production Based on Fuel Properties Derived from Fatty Acid Profiles

“…Saturated fatty acids (SFA) play a significant role in fuel properties. The CN increases in fuels with high amounts of SFA [11]. Biddulphia sp.…”

“…The CN of a fuel is related to the ignition delay time, which is the time between injection and ignition as referred in ASTM D613. The shorter the ignition delay time, the higher the CN, and vice versa [11]. According to the ASTM D6751-02 and EN14214 standard for biodiesel, the minimum CN should be 47.0 and 51.0, respectively, whereas the IV is set to a maximum of 120 g I 2 /100 g fat.…”

“…In addition to biomass and lipid productivities, lipid and oil content, quantitative and qualitative lipid and fatty acid compositions are regarded to be critical parameters for selecting algae species for large-scale production [10]. Furthermore, a good biodiesel should meet the cetane number (CN) standard, which indicates good ignition quality, a suitable cold filter plugging point, low pollutants content and, at the same time, correct density, and viscosity [11].…”

Engine performance of a single cylinder direct injection diesel engine fuelled with blends of Jatropha Curcas oil and standard diesel fuel

“…This can be related to the higher cetane number of the oil compared to diesel fuel and therefore that also affects blends tested. It is well known that higher cetane number shortening the ignition delay [8], [17]- [20].…”

Investigation of the Fatty Acid Profile in Some Macroalgae in Relation to the Environmental Conditions for Biodiesel Production

“…during spring. Factors that affect the CN in the biodiesel are the number of carbon atoms of the original fatty acids, the number of double bonds, the high amounts of SFA in addition to the type of feed stock (Gopinath et al, 2009;Tesfa et al, 2010).…”