A Study on Thermophysical Properties for Biodiesel Systems

Abstract

Fossil fuels are depleting at a rapid rate, due to their ever increasing demand and so there is a need for alternative and sustainable fuel. The search for alternatives to petroleum-based fuels has led to the development of fuels from various sources. Biodiesel is an alternative renewable fuel which has several advantages. The physio-chemical properties of fuel are important in design of fuel system for compression ignition engine run on diesel or biodiesel. The objective of this work is to do the detailed prediction of thermophysical properties of biodiesel systems to avoid experimental work, which is difficult, costly, and time consuming. In this work estimation of normal boiling point (Tnb), critical properties (Tc, Pc, V c), accentric factor (!), vapor pressure and density using various models has been done. The effect of Tc and Pc on vapor pressure was observed. Also the best suitable model of Tc, Pc estimation was proposed for vapor pressure prediction. Vapor pressure of fatty acid methyl esters (FAMEs) and fatty acid ethyl estres (FAEEs) were estimated using various models. The more emphasis is given to PR CEOS at zero pressure fugacity and Othmer & Yu models for estimation of Vapor pressure and normal boiling point temperature of biodiesel. The comparison of predicted and experimental values reported in literature was done for every properties of biodiesel by calculating percentage average relative deviation (%ARD).