A chemical factory at the South Pole is compressing ethylene for shipment to
consumers in the north. The temperature at the factory is 0°C, and the
factory is compressing the ethylene into large shipping tanks. A shipping tank
can hold a maximum allowable working pressure of 20 atm (gauge pressure -
actual number from online sources). Assume for this problem that the
atmospheric pressure is 1 atm.
The critical temperature for ethylene is 283.1 K
The critical pressure for ethylene is 50.5 atm
The molecular weight of ethylene is 28.05
The normal boiling point of ethylene is -103.7 °C
a) At 0°C, what is the highest absolute pressure (in atm) at which ethylene
still behaves as an ideal gas?
b) At 20 atm (gauge pressure) and 0°C, how many kg of ethylene can be put
into a 10 m3 tank?
c) The container is shipped to the Middle East, where the temperature is
42°C on a hot day. If the burst pressure of the tank is 25 atm, then will it
be safe to move without releasing any of the ethylene? (Assume non-
ideal gas behavior).
d) If one had assumed ideal gas behavior for the entire problem, then what
would be the percent error in the total mass in the tank at 0 °C?