So in your opinion, propane to ethylene. Thats -42C to -104C. Or a 62C boiling point delta. Do you think a partial phase separator would be necesary? R600 to R170 is a 89C boiling point delta.
I wish I could give you a definitive answer, but as you can imagine, it depends on a lot of different factors (eg; phase separator efficiency for one). Since I don't have ethylene or anything else with this same boiling point, I can't run a test. But you can