Lighter Crude Feed in Crude Distilling Unit
Lighter Crude Feed in Crude Distilling Unit
(OP)
What do I need to consider if I have to change the design of an existing Crude Distilling Unit that was designed for a 33 API feed to accomodate a 40-45 API feed?
The existing crude distilling unit does not have a pre-flash drum. Will a preflash drum placed after the pre-heat exchanger network and before the furnace help? If so, how do I design the preflash drum?
Do I need to change the overhead condensing system?
The existing crude distilling unit does not have a pre-flash drum. Will a preflash drum placed after the pre-heat exchanger network and before the furnace help? If so, how do I design the preflash drum?
Do I need to change the overhead condensing system?





RE: Lighter Crude Feed in Crude Distilling Unit
G. Gordon Stewart, P.Eng.
Gas & Oil Process Engineering Consultant
http://www.ggordonstewart.com/
ggstewar@telusplanet.net
RE: Lighter Crude Feed in Crude Distilling Unit
Yes,you put the Flash drum after the last heat exchanger,and you assume the bubble point of all components,with boiling points lower than the final exchanger temperature.
A good procedure for the design will be by using Hysis,otherwise the rigirous methods..
wayil@hotmail.com
RE: Lighter Crude Feed in Crude Distilling Unit
RE: Lighter Crude Feed in Crude Distilling Unit
injection at the crude after the
desalter. This will reduce the
amount of chlorides at the boot
of the overhead drum. You can
use both NH3 and filming amines
and target for a pH at the water
that your chemical vendor will
suggest. The tip of the story is
to use carefully the ammonia because
high ammonia concentrations can raise
the sublimation point of NH4CL above
the water dew point causing salt precipitation
prior to water condensation that will lead
to severe underdeposit corrosion.
Depending on your overhead system you may use
continious water recirculation prior to the
fin fan coolers.
RE: Lighter Crude Feed in Crude Distilling Unit
These data help you to get an idea of crude composition (cut-points) and products caracteristics (density, viscosity...)
The preflash drum placed after the pre-heat exchanger network and before the furnace will diminuate the operation pressure of the furnace and helps to get the accomodate flow in tubes.
since you have a lighter feed will change gasoline rate in the overhead,you can help with an air-cooler
using the industry simulation tools (like Hysis or PRO- II...) you can try and get the appropriate solution
good luck
RE: Lighter Crude Feed in Crude Distilling Unit
RE: Lighter Crude Feed in Crude Distilling Unit
I am new of using of hysys and I am trying to simulate the ammonia plant in hysys, but it seems that I got lost can anybody tell me from where to start and if any books or papers can help me in that
RE: Lighter Crude Feed in Crude Distilling Unit