The ternary diagram shown below is for Ethanol-Benzene-Water at 25°C.  A simple counter-current liquid-liquid  extraction system is to be designed to extract ethanol out of 60% benzene and  40% ethanol using a recycled water stream [containing 1% ethanol] as the  solvent [be careful here].  The benzene  phase must be reduced to 1% ethanol, and the two inlet streams are available at  the following flow rates:

Inlet Stream                 Flow

Benzene-ethanol          14  kg/s

Water-ethanol              8  kg/s

How many equilibrium stages are required to accomplish the  required separation?

 

Ethanol Benzene Water