A THERMODYNAMIC MODEL TO PREDICT WAX FORMATION IN PETROLEUM FLUIDS

Some years ago the authors proposed a model for the non-ideality of the solid phase, based on the Predictive Local Composition concept. This was first applied to the Wilson equation and latter extended to NRTL and UNIQUAC models. Predictive UNIQUAC proved to be extraordinarily successful in predicting the behaviour of both model and real hydrocarbon fluids at low temperatures. This work illustrates the ability of Predictive UNIQUAC in the description of the low temperature behaviour of petroleum fluids. It will be shown that using Predictive UNIQUAC in the description of the solid phase non-ideality a complete prediction of the low temperature behaviour of synthetic paraffin solutions, fuels and crude oils is achieved. The composition of both liquid and solid phases, the amount of crystals formed and the cloud points are predicted within the accuracy of the experimental data. The extension of Predictive UNIQUAC to high pressures, by coupling it with an EOS/G E model based on the SRK EOS used with the LCVM mixing rule, is proposed and predictions of phase envelopes for live oils are compared with experimental data

Crystallization of a multiparaffinic wax in normal tetradecane

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Prediction Of Cloud Points Of Biodiesel

The predictive UNIQUAC model, previously applied with success to the description of wax formation in fossil fuels, is extended here to the modeling of the precipitation of saturated and unsaturated fatty acid methyl/ethyl esters. Correlations for the thermophysical properties of the fatty acid esters are proposed, and the model is evaluated against experimental data of binary mixtures. Despite the lack of accurate data for the cloud points of biodiesel, the results obtained here allow for an adequate evaluation of the model proposed, showing that it can produce good predictions of the cloud points of mixtures of fatty acid esters. © 2008 American Chemical Society.222747752Hanna, M.A., Ma, F., (1999) Bioresour. Technol, 70, pp. 1-15Imahara, H., Minami, E., Saka, S., (2006) Fuel, 85, pp. 1666-1670Dunn, R.O., Bagby, M.O., (1995) J. Am. Oil Chem. Soc, 72, p. 895American Society for Testing and Materials (ASTM). Annual Book of ASTM StandardsASTM: West Conshohocken, PA, 199905.01Claudy, P., Létoffé, J.M., Neff, B., Damin, B., (1986) Fuel, 65, pp. 861-864Pauly, J., Daridon, J.L., Coutinho, J.A.P., Dirand, M., (2005) Fuel, 84, pp. 453-459Sansot, J.M., Pauly, J., Daridon, J.L., Coutinho, J.A.P., (2005) AIChE J, 51, pp. 2089-2097Coutinho, J.A.P., Gonçalves, C., Marrucho, I.M., Pauly, J., Daridon, J.L., (2005) Fluid Phase Equilib, 233, pp. 29-34Coutinho, J.A.P., Mirante, F., Pauly, J., (2006) Fluid Phase Equilib, 247, pp. 8-17Coutinho, J.A.P., Dauphin, C., Daridon, J.L., (2000) Fuel, 79, pp. 607-616Coutinho, J.A.P., (2000) Energy Fuels, 14, pp. 625-631Coutinho, J.A.P., Daridon, J.L., (2001) Energy Fuels, 15, pp. 1454-1460Daridon, J.L., Pauly, J., Coutinho, J.A.P., Montel, F., (2001) Energy Fuels, 15, pp. 730-735Pauly, J., Daridon, J.L., Coutinho, J.A.P., (2001) Fluid Phase Equilib, 187, pp. 71-82Mirante, F.I.C., Coutinho, J.A.P., (2001) Fluid Phase Equilib, 180, pp. 247-255Queimada, A.J.N., Dauphin, C., Marrucho, I.M., Coutinho, J.A.P., (2001) Thermochim. Acta, 372, pp. 93-101Coutinho, J.A.P., Mirante, F., Ribeiro, J.C., Sansot, J.M., Daridon, J.L., (2002) Fuel, 81, pp. 963-967Pauly, J., Daridon, J.L., Sansot, J.M., Coutinho, J.A.P., (2003) Fuel, 82, pp. 595-601Pauly, J., Daridon, J.L., Coutinho, J.A.P., (2001) Fluid Phase Equilib, 224, pp. 237-244Coutinho, J.A.P., Edmonds, B., Morwood, T., Szczepanski, B., Zhang, X., (2006) Energy Fuels, 20, pp. 1081-1088Costa, M.C., Krahenbuhl, M.A., Meirelles, A.J.A., Daridon, J.L., Pauly, J., Coutinho, J.A.P., (2007) Fluid Phase Equilib, 253, pp. 118-123Soave, G., (1972) Chem. Eng. Sci, 27, p. 1197Boukouvalas, C., Spiliotis, N., Coutsikos, P., Tzouvaras, N., Tassios, D., (1994) Fluid Phase Equilib, 92, pp. 75-106Boukouvalas, C.J., Magoulas, K.G., Stamataki, S.K., Tassios, D.P., (1997) Ind. Eng. Chem. Res, 36, pp. 5454-5460Peneloux, A., Rauzy, E., Freze, R., (1982) Fluid Phase Equilib, 8, pp. 7-23Coutinho, J.A.P., Knudsen, K., Andersen, S.I., Stenby, E.H., (1996) Chem. Eng. Sci, 51, pp. 3273-3282Coutinho, J.A.P., Stenby, E.H., (1996) Ind. Eng. Chem. Res, 35, pp. 918-925Coutinho, J.A.P., Ruffier-Meray, V., (1997) Ind. Eng. Chem. Res, 36, pp. 4977-4983Coutinho, J.A.P., (1998) Ind. Eng. Chem. Res, 37, pp. 4870-4875Coutinho, J.A.P., (1999) Fluid Phase Equilib, 160, pp. 447-457Abrams, D.S., Prausnitz, J.M., (1975) AIChE J, 21, pp. 116-128Larsen, B.L., Rasmussen, P., Fredenslund, A., (1987) Ind. Eng. Chem. Res, 26, pp. 2274-2286Lopes, J.C.A., (2007) Prediction of Cloud Point of Biodiesel, , http://path.web.ua.pt/file/teselopes.pdf, M.Sc. Thesis in Portuguese, University of Aveiro, Aveiro, PortugalDorset, D.L., (2004) Crystallography of the Polymethylene Chain. An Inquiry into the Structure of Waxes, , Oxford University Press: New YorkPoling, B.E., Prausnitz, J.M., O'Connell, J.P., (2001) The Properties of Gases and Liquids, , 5th edMcGraw-Hill: New YorkWilson, G.M., Jasperson, L.V., (1996) AIChE Spring Meeting, , New Orleans, LAMarrero-Marejón, J., Pardillo-Fontdevila, E., (1999) AIChE J, 45, p. 615Joback, K.G., Reid, R.C., (1987) Chem. Eng. Commun, 57, p. 233Nikitin, E.D., Pavlov, P.A., Bogatishcheva, N.S., (2005) Fluid Phase Equilib, 235, pp. 1-6Han, B., Peng, D., (1993) Can. J. Chem. Eng, 71, pp. 332-333Yuan, W., Hansen, A.C., Zhang, Q., (2005) Fuel, 84, pp. 943-950Chickos, J.S., Nichols, G., Zhao, H., (2004) Thermochim. Acta, 424, pp. 111-121Bommel, M.J., Berg, G.J.K., Blok, J.G., Ekeren, P.J., Genderen, A.C.G., Miltenburg, J.C., Oonk, H.A.J., (2002) Fluid Phase Equilib, 202, pp. 109-120Krasnykh, E.L., Doubsky, J., Koutek, B., Verevkin, S.P., (2006) J. Chem. Thermodyn, 38, pp. 717-723Dörfler, H.D., Pietschmann, N., (1990) Colloid Polym. Sci, 268, pp. 567-577Lockemann, C.A., Schlünder, E.U., (1993) J. Chem. Eng. Data, 38, pp. 432-43