REPRESENTATION OF DEW AND BUBBLE POINT DATA IN BINARY SYSTEMS

Using new parameters in place of X or Y in the X vs. V relations proposed by Hirata and Clark, dew point line and bubble point line can be expressed in two or three straight lines, closely similar to those of Hirata''s method or Clark''s method. The parameters used in this paper corresponding to Hirata''s X-Y method for dew point and bubble point curves are Method 1 : D1 vs. D2 and B2 vs. B1 Method 2 : D3 vs, Y and X vs. B3 Method 3 : D3 vs. D4 and B4 vs. B3in which X≡x11/x2, Y≡y1/y2, D1≡a1/(1-a1), D2≡a2/(1-a2), D3≡(1-a2)/(1-a1), D4≡a1/a2, B1≡(1-b1)/b1, B2≡(1-b2)b2, B3≡(1-b2)/(1-b1), and B4≡b1/b2. The values of a and b can be calculated by a=(π/P)y from dew point data and by b=(P/π)x from bubble point data, where x, y, P, and π, respectively, express mole fraction in liquid phase, that in vapor phase, vapor pressure, and total pressure. Corresponding to Clark''s X-Y relations, three sets of methods are also proposed for representation of dew point and bubble point curves by using the new parameters mentioned above.