Correlating the Cloud Point of Biodiesel to the Concentration and Melting Properties of the Component Fatty Acid Methyl Esters

Abstract

Biodiesel is a renewable alternative diesel fuel made from plant oils and animal fats. In the form of fatty acid methyl esters (FAMEs), it is usually obtained by transesterification of plant oil or animal fat with methanol in the presence of catalyst. Most of the fuel properties of biodiesel compare well with conventional diesel fuel (petrodiesel). One major disadvantage of biodiesel is its relatively poor cold flow properties which must be monitored during cold weather in moderate temperature climates. Two correlation models were developed to accurately calculate the cloud point (CP) of biodiesel. Both models were developed using measured CP data from binary admixtures of biodiesel fuels made from canola, palm, and soybean oils and yellow grease (CaME, PME, SME, and YGME). One model was based on solid–liquid equilibrium (SLE) thermodynamics in organic mixtures. This model required fatty acid concentrations (FA profile) and melting point (MP) and enthalpy of fusion (ΔHfus) data for each FAME species in th...