A to F step by step

Relatively pure oxygen is required in a large number of applications ranging from incubators for premature babies in neo-natal intensive care units to the use of oxygenation reactions in the production of various chemicals. An attractive way of generating this high purity oxygen is to use a small distillation column, with oxygen removed in the bottoms. The distillate, which is simply a more concentrated nitrogen stream, can be directly discharged into the atmosphere. The column obviously operates at very low temperatures (typically referred to as cryogenic distillation) to attain the desired VLE for the O2N2 system. A) A distillation column is to be designed to produce 99.5% pure oxygen from air (21\% O2 and 79%N2 ). The feed flow rate is 100 moles of air per second, and the column is operated so that 80% of the oxygen is recovered in the bottoms. Evaluate the composition and flow rates of both the bottoms and distillate. B) Although the vapor pressures for O2 and N2 are a strong function of temperature, the ratio of the vapor pressures (at any given temperature) is nearly constant with a relative volatility of =(yNN/yO22)(xN/xO2)=3.6. Construct the equilibrium plot of yN2 versus xN for the O2 and N2 system using this value of . Note: even though the goal of the separation is to purify the oxygen, it is typical to construct a plot of the equilibrium data using the more volatile component (in this case nitrogen) C) Evaluate the minimum number of stages for the separation using a McCabe-Thiele analysis. D) Compare your result in part C with that determined from the Fenske equation. E) Evaluate the minimum reflux (Lmin) assuming that the air that is fed to the column as a liquid (liquified before adding to the column). F) The actual column is operated with a reflux ratio ( L/d) set at 3 times the minimum reflux. Evaluate the operating lines and determine the actual number of equilibrium stages required to effect the separation using a McCabe-Thiele diagram