Fifty wt% methylcyclohexane (MCH) in n-heptane is fed to a countercurrent, stage-type extractor at 25 C.

Fifty wt% methylcyclohexane (MCH) in n-heptane is fed to a countercurrent, stage-type extractor at 25^οC. Aniline is the solvent and reflux is used at both ends of the column. An extract containing 95 wt% MCH and a raffinate containing 5 wt% MCH (both on a solvent-free basis) are required. The minimum extract reflux ratio is 3.49. Using a right-triangle diagram with the data of Exercise 8.22, calculate the: 

(a) Raffinate reflux ratio, 

(b) Amount of aniline that must be removed at the separator ‘‘on top’’ of the column, and 

(c) Amount of solvent added to the solvent mixer at the bottom of the column.

Data From Exercise 8.22

At 45C, 5,000 kg/h of a mixture of 65 wt% docosane, 7 wt% furfural, and 28 wt% diphenylhexane is to be extracted with pure furfural to obtain a raffinate with 12 wt% diphenylhexane in a continuous, countercurrent, multistage liquid–liquid extraction system.