Question

a binary mixture is to be fed a continuous distillation column. calculate the minimum number of trays required to achieve a separate from 4 mole percentage to 96 mole percentage distillate in a binary column with alpha 2.5

Answer 1

minimum number of trays:

N = 7 trays

Step-by-step explanation:

minimum number (N):

• N = ( Log ( (Xd / ( 1 - Xd )) * (( 1 - Xb ) / Xb )) ) / Log α....Fenske's Eq. binary mixture

∴ α = 2.5

∴ Xd = 0.96.......molar fraction the distillate

∴ Xb = 0.04 .........molar fraction in the bottoms

⇒ N = ( Log ( ( 0.96 / ( 1 - 0.96 ) ) * ( ( 1 - 0.04 ) / 0.04 )) ) / Log ( 2.5 )

⇒ N = 6.94 ≅ 7 trays