distillation column pressure
Posted: 14 May 2018, 05:45
i have the following utilities to use:
Available steam for reboiler: 25 psig and 100 psig
Cooling water: 30 C
Delta temperature approach between process and utility: >20C, <90C
My questions are
1. Should the bubble point temperature of the condenser be at least 50C to accommodate the cooling water temperature and the delta approach? if so, since l know the distillate composition can l calculate the bubble point pressure that will result in bubble point temperature of 50C, in this case -6.5 psig as shown in the attachment?
2. for the re-boiler, is the pressure not fixed by the condenser pressure less stage pressure drops, if so why are we given steam pressure, not temperature for the re-boiler utilities. How then do l determine the required re-boiler pressure?
Available steam for reboiler: 25 psig and 100 psig
Cooling water: 30 C
Delta temperature approach between process and utility: >20C, <90C
My questions are
1. Should the bubble point temperature of the condenser be at least 50C to accommodate the cooling water temperature and the delta approach? if so, since l know the distillate composition can l calculate the bubble point pressure that will result in bubble point temperature of 50C, in this case -6.5 psig as shown in the attachment?
2. for the re-boiler, is the pressure not fixed by the condenser pressure less stage pressure drops, if so why are we given steam pressure, not temperature for the re-boiler utilities. How then do l determine the required re-boiler pressure?