Question

Methylene dichloride (CH­₂Cl₂) is used to recover caffeine (C­­₈H₁₀N₄O₂) from 1000 kg/h of coffee beans (containing 0.2% caffeine) in a 4-stage countercurrent wash. Coffee bean slurry entrains 2 wt% CH­₂Cl₂ (solute free basis). What percent caffeine recovery at 2.5 times the minimum flowrate of CH­₂Cl₂? What CH­₂Cl₂ flowrate (in kg/h) is needed to recover 99% of C­­₈H₁₀N₄O₂? (you do not need more info)

Answer 1