Overview The VLE data are essential for many engineering calculations, especially in the design and analysis of separation processes such as distillation, absorption, etc... Thermodynamics provides a system of equations relating the necessary experimental data and the unknown vapour-liquid equilibrium compositions, temperature and pressure. The experimental VLE data for many systems are available from the databases such as shown Dortmund Data Bank and NIST. Journal of Fluid Phase Equilibria and Journal of chemical & engineering data specialize in the publication of high-quality papers dealing with experimental, theoretical and applied research related to equilibrium and transport properties of fluids, solids, and interfaces. Instructions The experimental VLE data of Lee et al. (1997) is reported in Table 1 below. Determine the binary interaction fitting parameter for this data set using the phi-phi method. Use the Peng- Robinson Equation of State (PREOS) (1976) with the van der Waals mixing rules. However, in the PREOS replace the a function with the following a function of Mathias and Copeman (1983) reduced to 3 adjustable parameters: a{{p.),c}=[1+x (1-MT).)+w; (1-NT.), ) +63(1-1))] (1) Te is the critical temperature, w is the acentric factor, Tr is the reduced temperature, K1, K2 and Kz are the adjustable parameters that are unique to each component. - 3 - Table 1: Experimental VLE data of MTBE (1) + methyl acetate (2) at 373.17 K, (Lee et al, 1997). Pressur kPa 373.3 387.3 396.2 402.9 405.0 404.8 404.5 403.2 401.8 396.0 387.9 377.3 363.8 X1 yi mole fraction mole fraction 0 0 0.0956 0.122 0.191 0.222 0.295 0.317 0.405 0.412 0.462 0.459 0.485 0.479 0.540 0.526 0.581 0.560 0.683 0.650 0.787 0.751 0.896 0.870 1 1