Design of Adsorption Unite: An ethylene$-$air mixture is contained in a $10m3$ volume source at a temperature $37C$ and a pressure $78\frac{N}{m}2\mathrm{.}81\%$ is the relative saturation of air by the ethylene vapour. The design requires certain quantity of adsorbent to bring down the saturation by $10\%$ at $37C.$