Investigation of Correlations for Prediction of Critical Properties of Pure Component

Prediction of accurate values of critical properties of any pure component is very important because they are often utilized in estimating the physical properties for chemical process design. Experimental measurements of critical properties for components are very difficult. So in order to obtain accurate critical property values, attention has been turned to calculate it using mostly a group contribution method which is difficult method. To overcome this problem efforts where directed to modify or improve equations to calculate critical properties using relatively simple method. In this method, critical temperature,
critical volume and critical pressure can be estimated solely from data of the normal boiling point and molecular weight of pure substance by means of successive approximations that are repeated until calculation of critical pressure (P) converges.The procedure can be summarized as follows:
1. Calculation of critical temperature.
2. Assuming suitable value of critical pressure and calculating critical volume.
3. Calculation of critical compressibility factor.
4. Calculation of critical pressure from the following equation ;