INVESTIGATION of the CORRELATIONS P- V- T of COMPRESSED LIQUIDS at HIGH PRESSURES

Prediction of the accurate values of molar volume of compressed liquids is very important in process design calculation and other industrial applications. Experimental measurements of molar volume V for compressed fluids are  very expensive , so in order to obtain accurate V values, attention has been turned to calculate it from equation of state   Alto and Kiskinen[1] equation for pure non polar component,  using correlations to Tait equation for polar component, and modification of Rackett equation are used for mixtures. In this study five types of equations of state were used to calculate molar volume V for pure non polar compressed liquid, they are Alto and Kiskinen, Tait, Peng- Robinson, Soave-Redlich- Kowng, Lee- Kesler. These equations were tested against 241 experimental data points of pure non polar
compressed liquids and it was found that Aalto and Kiskinen equation is the best compared with the other equations.  The results of Alto and Kiskinen gives the average absolute percent deviation of 11 pure components was 0.6276. For pure polar compound using four equations of state, Soave- Redlich- Kowng,Peng- Robinson, Alto and Kiskinen, Tait. These equations were tested against 63 experimental data points of polar compressed liquids and it was found that Tait equation is the best compared with the other equations.  A new correlation for Tait equation was made to improve its accuracy and this was done by replacing the two terms in Tait equation (pressure and vapor pressure) with reduced pressure