A tray-type distillation tower is to be used for separating a propane/propylene mixture. The multi-component feed to the tower is completely vapor at a temperature of 43.3 C, a pressure of 1668 kPa (absolute pressure), and a composition as shown below. Component Acetylene Ethylene Ethane 1,3-Butadiene i-Butene 1-butene Propylene Propane Mass flow rate, kg/s 1.3x10-6 1.3X10-6 3.3X10-4 3.7X10-4 1.9X10-4 1.2X10-4 6.41 4.62 A production with a propylene concentration of 99.6 mol percent is desirable. It is also found that a propylene concentration of 0.0022 mole percent in the process stream leaving the bottom of the distillation column. From the simulation results, the vapor density is 27 kg/m and the liquid density is 476 kg/m. And the maximum vapor molar flow rate is found to be 2.53 kmol/s. (hints: you can assume that other materials negligible other than propylene and propane). (1) Use short-cut method (FUG Method) to determine the number of trays required for accomplishing the separation task;