The critical temperatures of multicomponent hydrocarbon systems

The critical temperature of any multicomponent hydrocarbon system may be established solely from the normal boiling points of the pure constituents. Such mixtures may include normal paraffins, isoparaffins, olefins, acetylenes, naphthenes, and aromatics and may contain an unlimited number of components. An expression has been developed for the prediction of the critical temperatures of mixtures and has been tested on fifty‐five hydrocarbon systems containing from two to five components. For 208 binary mixtures the deviations from reported values were calculated, and the maximum deviations resulting from each system were averaged for the forty‐one binary systems to produce an average maximum deviation of 0.91% based on degrees absolute. For twenty‐eight multicomponent mixtures reported for nine ternary, two quaternary, and three quinary systems the average deviation was 1.03%. This method presents a simple and accurate means of establishing the critical temperature of any multicomponent hydrocarbon mixture as long as the ratio of the normal boiling points of the heaviest and lightest components present in the mixture does not exceed the prescribed limits.