It has been established that an existing distillation column in your plant can separate hydrocarbon mixture efficiently, when operated on a continuous basis. You are,however, informed by your mechanical engineer that the pressure at the top of the column must not exceed 320 kPa. Only cooling water is available on the plant and thus the top temperature of the column is thus limited to 45°C. Do dew point temperature calculations to determine whether the restrictions mentioned above prevent you from recommending that the column may be used if the overhead vapour has the following composition:

It can be assumed that these hydrocarbons form an ideal solution and that Raoult`slaw can be used to determine the K– values. The following formula can be used to calculate the vapour pressure, p* of each component: log p* = AT + B where A and B are constants that are given in the table4 below and T is the temperature in K and the unit of p* is kPa.