Prediction of water solubility in biodiesel with the CPA equation of state

abstract

The recent growing interest in biofuels is due to the continuous increase in crude oil prices, limited resources of fossil energies, and environmental concerns. In what concerns road transportation, biodiesel is being considered a good alternative to conventional diesels. It consists of a blend of fatty acid esters, and its production and formulation needs to be optimized to ensure that the fuel quality complies with the legal standards. Although in various aspects biodiesel is superior to conventional diesel, it also poses some problems such as its poor behavior at low temperatures and higher hygroscopicity than conventional diesel. Up to now, little information is available about the water solubility in fatty acid methyl and ethyl esters and commercial biodiesels. To overcome this lack of data, water solubility measurements were carried out for 11 pure esters and 6 biodiesels in the temperature range 288.15-323.15 K. This new experimental data was successfully modeled with the cubic-plus-association (CPA) equation of state with global average deviations inferior to 7% for the ester systems, and predictions with deviations of 16% for commercial biodiesels were achieved.

keywords

LIQUID-LIQUID EQUILIBRIA; ESTERS TERNARY-SYSTEMS; CORRELATION GAS-CHROMATOGRAPHY; ACID METHYL-ESTERS; PHASE-EQUILIBRIA; VAPOR-PRESSURES; MUTUAL SOLUBILITIES; ELEVATED PRESSURES; VAPORIZATION ENTHALPIES; ASSOCIATING SYSTEMS

subject category

Engineering

authors

Oliveira, MB; Varanda, FR; Marrucho, IM; Queimada, AJ; Coutinho, JAP

our authors

Share this project:

Related Publications

We use cookies for marketing activities and to offer you a better experience. By clicking “Accept Cookies” you agree with our cookie policy. Read about how we use cookies by clicking "Privacy and Cookie Policy".