The contaminated concentration in the cabin of an aeroplane is 1 wt%. Design a cross vent multistage operation with three stages. what are the intermediate concentration for the solution with the target output at thousand ppm the spent absorbent concentration is 0.005. the fresh absorbent is used. the isotherm obeyed is langmare isotherm with k=0.413. what is the ratio of the adsorbent used to the solution feed rate proceed?