Cetane Number Prediction of Biodiesel from the Composition of the Fatty Acid Methyl Esters

Abstract

In the present work, the measured cetane numbers (CN) of pure fatty acid methyl esters (FAME), as well as the FAME compositions and the reported CN of 59 kinds of biodiesels collected from literature were used to develop a simple model involving as more FAME component as possible for predicting CN of biodiesel from its FAME composition. Two different regression equations correlating the CN of pure FAME with the carbon number of fatty acid chain were obtained by regression analysis, which shows that the dependence of the CN on the carbon number varies with the unsaturated degree of fatty acid chain. The 59 biodiesels were divided into two categories and used, respectively to develop and test a multiple linear regression model (MLRM) correlating the CN of biodiesel with its FAME composition. A simple and convenient regression equation with a high accuracy and a good reproducibility (average absolute error of 0.49 CN for testing set and 1.52 CN for all data) were developed, showing excellent correlation (R 2 : 0.9904 for testing set). The model developed in the present work can be used conveniently to give a satisfactory predicted CN of biodiesel from the FAME composition.

Microalgal fatty acid composition: implications for biodiesel quality

“…CN was estimated in this work using a combination of models from the work of Lapuerta et al (2009) and Tong et al (2010). The CNs of individual FAs were calculated using the equations below, where n is the carbon number and db is the number of double bonds.…”

“…However, there have been several attempts to develop models that predict some of the critical biodiesel properties from its composition (e.g. Allen et al 1999;Dunn 2008;Imahara et al 2006;Lapuerta et al 2009;Lopes et al 2008;Tong et al 2010). These models then allow the preliminary evaluation of potential feedstocks (in this case algae) if the fatty acid (FA) composition is known.…”

Impact of antioxidant additives on the oxidation stability of biodiesel produced from Croton Megalocarpus oil

“…This suggests that there is a need for using a cetane number enhancing additive, when using COME as mineral diesel replacement. Additionally, the lower cetane number of COME possible was attributed to the presence of high polyunsaturated fatty acid methyl esters (78.5%) [19]. The lubricity of COME (202 μm) was well within the acceptable limits of 460 μm and 520 μm as prescribed in mineral diesel standards EN 590 and ASTM D975 respectively [20].…”

Fuel Property Determination of Biodiesel-Diesel Blends By Terahertz Spectrum

“…The ester group will rupture from the chain and break down into free radical, improving the ignition of fuel. So myristatethe, palmitate, stearate and oleate have the relatively higher CNs of 66.2, 74.3, 75.6 and 64.8, respectively, and the CN of biodiesel is about 66 [22]. Futhermore, esters showed higher kinematic viscosity than hydrocarbons, leading to an easier paraffin crystallization and worse flow property at low temperature of biodiesel than diesel [23].…”