Overall distillation column efficiency for most of the refinery columns can be given by (for $$\mu $$ = 0.07 - 1.4 cp and relative volatility < 4) (where η = overall column efficiency, % $$\mu $$ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi)

A. η = 17 - 61.1 log $$\mu $$

B. η = 24.6 $$\frac{{\Delta {\text{p}}}}{\mu }$$

C. η = 1.66 - 0.25 log $$\mu $$

D. η = 0.25 log $$\mu $$ - 1.67

Answer: Option A