Operating line AB is drawn in xy plane. Any point (x,y) is taken in operating line. A vertical line is drawn upto equilibrium line to get y*.

Design based on height of a transfer unit (HTU)

quantity is called ‘height if transfer units’ (HTU) and designated as HtG. It is important to measure the separation effectiveness of the particular packings for a particular separation process. It also describes the mass transfer coefficient. Larger mass transfer coefficient leads to the smaller value of HTU. Hence

Design Equations based concentration in mole ratio unit

If kx, ky are individual gas phase mass transfer coefficients and KY is overall gas phase mass transfer coefficient, height of packed tower is expressed as: