engleski

Determination and Evaluation of Phase Equilibrium Data in Polymer-Solvent Systems

Transport of oil products, namely crude oil, gas condensate and derivatives, requires flow improver additives for optimal realization. These compounds, already in low concentrations, are able to improve significantly flow properties of transported material. It was found [1, 2] that one class of efficient additives consists of copolymers and terpolymers synthesized by polymerization of long chain methacrylates with styrene and (meth)acrylic acid and styrene or 1-vinyl-2-pyrrolidone. Such polymeric improver additives have already been exploited with excellent results as the means for separation of paraffinic fractions being responsible for increased viscosity and pour point. For future development of better additives, the group contribution method represents a powerful tool ; however the evaluation of particular group increments must be based on thermodynamic data on systems which are not hitherto available. In this work, liquid– vapor equilibria were determined ebulliometrically for several systems consisting of the above mentioned terpolymer + organic solvent at different temperatures and pressures. Subsequently, this data base is used for evaluation of the first approximation of necessary input data. Prediction of phase equilibrium compositions has been carried out with use of three group contribution models: the Entropic-FV model [3], the GC-Glory EOS [4] and the GC-LF EOS [5, 6]. References [1] A. Erceg Kuzmić, M. Radošević, G. Bogdanić, R. Vuković, Fuel 86 (2007) 1409. [2] A. Erceg Kuzmić, M. Radošević, G. Bogdanić, V. Srića, R. Vuković, Fuel, in press. [3] G. M. Kontogeorgis, Aa. Fredenslund, D. P. Tassios, Ind. Eng. Chem. Res. 31 (1993) 362. [4] G. Bogdanić, Aa. Fredenslund, Ind. Eng. Chem. Res. 33 (1994) 1331. [5] M. S. High, R. P. Danner, AIChE J. 36 (1990) 1625. [6] M. S. High, R. P. Danner, Fluid Phase Equilib. 53 (1989) 323. The authors acknowledge the partial support of the Grant Agency of the Czech Republic (Grant No. 104/07/0444) and of the Ministry of Science, Education and Sports of the Republic of Croatia.

vapour-liquid equilibrium; phase equilibrium data; polymer-solvent systems

nije evidentirano