Two schemes are proposed for the reduction in pressure of ethylene gas at 375 K and
18 bar to 1.2 bar in a steady-flow process:
(a) Pass it through a throttle valve.
(b) Send it through an adiabatic expander of 70% efficiency.
For each proposal, determine the downstream temperature, and the rate of entropy
generation in J⋅mol−1⋅K−1. What is the power output for proposal (b) in kJ⋅mol−1?
Discuss the pros and cons of the two proposals. Do not assume ideal gases.