Multicomponent distillation Erbar—Maddox method

There are several valuable references to developing and applying a multicomponent distillation program, including Holland [26, 27,169], Prausnitz [52, 53], Wang and Henke [76], Thurston [167], Boston and Sullivan [6], Maddox and Erbar [115], and the pseudo-K method of Maddox and Fling [116]. Convergence of the iterative trials to reach a criterion requires careful evaluation [114]. There are sever-... 

The two most frequently used empirical methods for estimating the stage requirements for multicomponent distillations are the correlations published by Gilliland (1940) and by Erbar and Maddox (1961). These relate the number of ideal stages required for a given separation, at a given reflux ratio, to the number at total reflux (minimum possible) and the minimum reflux ratio (infinite number of stages). 

NUMBER OF IDEAL PLATES AT OPERATING REFLUX. Although the precise calculation of the number of plates in multicomponent distillation is best accomplished by computer, a simple empirical method due to Gilliland is much used for preliminary estimates. The correlation requires knowledge only of the minimum number of plates at total reflux and the minimum reflux ratio. The correlation is given in Fig. 19,5 and is self-explanatory. An alternate method devised by Erbar and Maddox is especially useful when the feed temperature is between the bubble point and dew point. 

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