In this configuration the total feed to the unit is debutanized in the first tower.
The butanes and lighter hydrocarbons are totally condensed and collected in the
column’s overhead drum. Part of this condensate is returned to the tower top tray as
reflux. The remainder is routed to a depropanizer column. The bottom product from
the debutanizer is the full range naphtha product. This enters a naphtha splitter
column where it is fractionated to give an overhead distillate of light naphtha and a
bottom product of heavy naphtha.
The depropanizer separates the debutanizer overhead distillate to give a propane
fraction as an overhead distillate stream and the butane fraction (butane LPG) as the
bottom product. The overhead distillate is fractionated in a deethanizer column to
produce a rich propane stream (propane LPG) as the bottom product. The overhead
from this column is predominately hydrocarbons lighter than propane. This stream
is only partially condensed to provide reflux for the tower. The uncondensed vapor
is normally routed to the refinery’s fuel gas system.
The products from the “light ends” unit are as follows:
Naphtha splitter – light naphtha (overhead distillate)
Heavy naphtha (bottom product-reformer feed)
Depropanizer – butane LPG (bottom product)
Deethanizer – propane LPG (bottom product)
Fuel gas (overhead vapor)
CW
CW
LSR
Naphtha
Fuel Gas
CW
CW
Crude Unit
O/heads
DEBUTANISER NAPHTHA SPLITTER
DEPROPANISER
Platformer Feed
Butane LPG
Propane LPG
DE ETHANISER
Fig. 1 A typical light ends unit configuration
Distillation of the ‘‘Light Ends´´ from Crude Oil in Petroleum Processing
201
The butanes and lighter hydrocarbons are totally condensed and collected in the
column’s overhead drum. Part of this condensate is returned to the tower top tray as
reflux. The remainder is routed to a depropanizer column. The bottom product from
the debutanizer is the full range naphtha product. This enters a naphtha splitter
column where it is fractionated to give an overhead distillate of light naphtha and a
bottom product of heavy naphtha.
The depropanizer separates the debutanizer overhead distillate to give a propane
fraction as an overhead distillate stream and the butane fraction (butane LPG) as the
bottom product. The overhead distillate is fractionated in a deethanizer column to
produce a rich propane stream (propane LPG) as the bottom product. The overhead
from this column is predominately hydrocarbons lighter than propane. This stream
is only partially condensed to provide reflux for the tower. The uncondensed vapor
is normally routed to the refinery’s fuel gas system.
The products from the “light ends” unit are as follows:
Naphtha splitter – light naphtha (overhead distillate)
Heavy naphtha (bottom product-reformer feed)
Depropanizer – butane LPG (bottom product)
Deethanizer – propane LPG (bottom product)
Fuel gas (overhead vapor)
CW
CW
LSR
Naphtha
Fuel Gas
CW
CW
Crude Unit
O/heads
DEBUTANISER NAPHTHA SPLITTER
DEPROPANISER
Platformer Feed
Butane LPG
Propane LPG
DE ETHANISER
Fig. 1 A typical light ends unit configuration
Distillation of the ‘‘Light Ends´´ from Crude Oil in Petroleum Processing
201