Current concerns regarding the environmental and economic sustainability of petroleum-based transportation fuels, including jet fuel, are driving interest into alternative fuels. To study the feasibility of using biodiesel in aviation engines, a deeper knowledge on solid–liquid equilibrium (SLE) of biodiesel/jet fuel blends is required. This work presents SLE data of binary mixtures containing p-xylene, a representative compound of aviation fuel, and fatty esters present in ethylic biodiesel. Experimental data were obtained through differential scanning calorimetry. A simple eutectic behavior was observed for all binary systems, although small regions of partial miscibility are also present. Observed eutectic temperature and composition (ethyl ester mole fraction) are 259.0 K and 0.45, 269.0 K and 0.32, 275.5 K and 0.22, 280.0 K and 0.15, and 247.7 K and 0.58 for systems containing ethyl laurate, ethyl myristate, ethyl palmitate, ethyl stearate and ethyl oleate, respectively. Good agreement was obtained between experimental and calculated data when using UNIFAC (Dortmund) model or Flory–Huggins equation, with root-mean-square deviations ranging from 0.47 to 1.90 K. The systems exhibit significant deviations from ideality, which cannot be neglected in model calculations.
This is a preview of subscription content, log in to check access.
Authors wish to acknowledge the Brazilian agencies CAPES—Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, FAPESP—Fundação de Amparo à Pesquisa do Estado de São Paulo (Grant Numbers 2018/06956-2, 2014/21252-0 and 2010/18355-1), and CNPq—Conselho Nacional de Desenvolvimento Científico e Tecnológico (Grant Numbers 304906/2014-0 and 150950/2014-4) for their financial support.
Karatzos S, van Dyk JS, McMillan JD, Saddler J. Drop-in biofuel production via conventional (lipid/fatty acid) and advanced (biomass) routes. Part I. Biofuels, Bioprod Biorefin. 2017;11(2):344–62. https://doi.org/10.1002/bbb.1746.Google Scholar
Boros L, Batista MLS, Vaz RV, Figueiredo BR, Fernandes VFS, Costa MC, et al. Crystallization behavior of mixtures of fatty acid ethyl esters with ethyl stearate. Energy Fuels. 2009;23(9):4625–9. https://doi.org/10.1021/ef900366z.Google Scholar
Costa MC, Boros LAD, Coutinho JAP, Krähenbühl MA, Meirelles AJA. Low-temperature behavior of biodiesel: solid–liquid phase diagrams of binary mixtures composed of fatty acid methyl esters. Energy Fuels. 2011;25(7):3244–50. https://doi.org/10.1021/ef2004199.Google Scholar
Benziane M, Khimeche K, Dahmani A, Nezar S, Trache D. Experimental determination and prediction of (solid + liquid) phase equilibria for binary mixtures of heavy alkanes and fatty acids methyl esters. J Therm Anal Calorim. 2013;112(1):229–35. https://doi.org/10.1007/s10973-012-2654-2.Google Scholar
Robustillo MD, Parra DF, Meirelles AJA, Pessôa Filho PA. Solid–liquid equilibrium of binary and ternary systems formed by ethyl laurate, ethyl palmitate and n-decane: experimental data and thermodynamic modeling. Fluid Phase Equilib. 2016;426:83–94. https://doi.org/10.1016/j.fluid.2016.01.044.Google Scholar
Moura-Nickel CD, Contarti da Cruz LC, Igarashi-Mafra L, Yamamoto CI, Rolemberg MP, Mafra MR. Determination of cloud point in binary and ternary mixtures containing biodiesel and diesel constituents. Part I – ethyl palmitate, ethyl stearate and n-hexadecane. Fuel. 2016;180:442–7. https://doi.org/10.1016/j.fuel.2016.04.054.Google Scholar
Robustillo MD, Bessa LCBA, Meirelles AJA, Pessôa Filho PA. Experimental data and thermodynamic modeling of solid–liquid equilibrium of binary systems containing representative compounds of biodiesel and fossil fuels: ethyl esters and n-hexadecane. Fuel. 2018;220:303–17. https://doi.org/10.1016/j.fuel.2018.01.117.Google Scholar
Robustillo MD, Meirelles AJA, Pessôa Filho PA. Solid–liquid equilibrium of binary and ternary systems formed by ethyl laurate, ethyl palmitate and dodecylcylohexane: experimental data and thermodynamic modeling. Fluid Phase Equilib. 2016;409:157–70. https://doi.org/10.1016/j.fluid.2015.09.038.Google Scholar
Benziane M, Khimeche K, Trache D, Dahmani A. Experimental determination and prediction of (solid + liquid) phase equilibria for binary mixtures of aromatic and fatty acids methyl esters. J Therm Anal Calorim. 2013;114(3):1383–9. https://doi.org/10.1007/s10973-013-3147-7.Google Scholar
Chevron. Aviation Fuels - Technical Review. San Ramon, CA. 2007.Google Scholar
Collinet E, Gmehling J. Activity coefficient at infinite dilution, azeotropic data, excess enthalpies and solid–liquid-equilibria for binary systems of alkanes and aromatics with esters. Fluid Phase Equilib. 2005;230(1–2):131–42. https://doi.org/10.1016/j.fluid.2004.12.005.Google Scholar
Basso RC, da Silva CA, de Oliveira Sousa C, de Almeida Meirelles AJ, Batista EAC. LLE experimental data, thermodynamic modeling and sensitivity analysis in the ethyl biodiesel from macauba pulp oil settling step. Bioresour Technol. 2013;131:468–75. https://doi.org/10.1016/j.biortech.2012.12.190.Google Scholar
Carareto NDD, dos Santos AO, Rolemberg MP, Cardoso LP, Costa MC, Meirelles AJA. On the solid–liquid phase diagrams of binary mixtures of even saturated fatty alcohols: systems exhibiting peritectic reaction. Thermochim Acta. 2014;589:137–47. https://doi.org/10.1016/j.tca.2014.05.022.Google Scholar