ABSTRAKT

Thermodynamic stability (spinodal) limits are determined for several binary hydrocarbon mixtures of N-methyl-α-pyrrolidone, NMP(1), with alkanes(2). Using the NRTL model, rigorous criteria for both intrinsic stability and criticality conditions are derived and solved numerically using MATLAB. In addition, the spinodal and binodal data are tested for compliance with the critical universality theory. Results indicate that the binary liquid systems of NMP with the considered alkanes represent a universal class such that the binodal and spinodal information for other binary mixtures of NMP within the same class can be predicted using simple power law models. Spinodal and miscibility gaps for binary liquid mixtures of NMP with alkanes not included in the database are predicted and found to be in excellent agreement with those obtained from the developed thermodynamic criteria and the experimental binodal data. The developed simple power law model is very helpful in easy and quick estimation of liquid-liquid equilibrium data.