200 kg/h of a benzene and triethylamine (TMA) solution (30 wt % TMA) are to be separated by a liquid-liquid extraction process using pure water as a solvent. The water free reffinate should contain 5 wt% TMA. a) Calculate the minimum amount of solvent water corresponding to an infinite number of stages. For this amount of solvent what is the corresponding composition of extract? (b) Use a flowrate of solvent (pure water) equal to 130 kg/h to calculate the compositions and amounts of the ether extract and the aqueous raffinate. How many stages are required to achieve the desired raffinate composition?

 

90 80 70 60 50 40 30 20 100 Water 0 10 20 20 TMA 10 10 0 100 90 30 30 40 200 80 50 50 70 70 60 60 60 890 50 40 70 80 60 30 20 10 0 90 100 Benzene