High-precision correlation method and phase equilibrium estimation method for phase equilibrium data

摘要

Provided are a method for precisely predicting phase equilibrium from existing phase equilibrium data on the basis of a wide range of phase equilibrium data including binary vapor-liquid equilibrium data; a method or apparatus for designing or controlling a component separator or a refiner using the prediction method; and a program for designing this design or control apparatus. Binary phase equilibrium measurement data is used to calculate an index X of proximity ratio to critical points that is represented by the following equation (22) and infinite dilution pressure gradients Y 1 and Y 2 that are represented by the following equations (24) and (25): Index X of proximity ratio to critical points: [Formula 1] X = p 1 �¢ s + p 2 �¢ s P c �¢ 1 + p 2 �¢ s Infinite dilution pressure gradients Y 1 and Y 2 : [Formula 2] Y 1 = ³ 1 ˆž �¢ p 1 �¢ s - p 2 �¢ s P c �¢ 1 - p 2 �¢ s [Formula 3] Y 2 = p 1 �¢ s - ³ 2 ˆž �¢ p 2 �¢ s P c �¢ 1 - p 2 �¢ s wherein P c1 represents the critical pressure of component 1 in the binary system; p 1s and p 2s represent the vapor pressures of components 1 and 2, respectively, at a temperature T; and ³ i ˆž represents the infinite dilution activity coefficient of component i in the liquid phase. The obtained index X is correlated with Y 1 and Y 2 to newly calculate infinite dilution activity coefficients ³ 1 ˆž and ³ 2 ˆž or binary parameters A and B from the X-Y 1 correlation and the X-Y 2 correlation, respectively. The obtained values of ³ 1 ˆž and ³ 2 ˆž or A and B are used to predict phase equilibrium. The thus obtained values are used to design or control a component separator or a refiner, such as a distillation column.