An 11.5 wt% mixture of acetic acid in water is to be extracted with 1-butanol in a counter-current extraction at 1 bar pressure and 26.7°C. Outlet concentrations of 0.5 wt% in the water and 9.6 wt% in...

An 11.5 wt% mixture of acetic acid in water is to be extracted with 1-butanol in a counter-current extraction at 1 bar pressure and 26.7°C. Outlet concentrations of 0.5 wt% in the water and 9.6 wt% in the 1-butanol are required. Inlet butanol is pure and the equilibrium relationship is y = 1.613x, where y and x are the weight fraction of acetic acid in 1-butanol and water respectively. Find the number of equilibrium stages required and state the ratio of water to 1-butanol required for the separation.