Redo Problem 3.32 using Aspen Plus.

Problem 3.32

Nitrogen can be liquefied using a Joule-Thomson expansion process. This is done by rapidly and adiabatically expanding cold nitrogen gas from high pressure to a low pressure. If nitrogen at 135 K and 20 MPa undergoes a Joule-Thomson expansion to 0.4 MPa, 

a. Estimate the fraction of vapor and liquid present after the expansion, and the temperature of this mixture using the pressure-enthalpy diagram for nitrogen.

b. Repeat the calculation assuming nitrogen to be an ideal gas with C^∗_P = 29.3 J/(mol K).