In petroleum refining, the Crude Distillation Unit (CDU) (often referred to as the Atmospheric Distillation Unit) is usually the first processing equipment through which crude oil is fed. Once in the CDU, crude oil is distilled into various products, like naphtha, kerosene, and diesel, that then serve as feedstocks for all other processing units at the refinery.

1. Industrial Training Presentation
Topic- Crude Distillation Unit (CDU)
Presented By-
Priyam Jyoti Borah
Roll no- 16/275
Department- Chemical

2. Crude Oil
Source
1. Assam Crude (Sulphur 0.3%)
2. Ravva Crude (Sulphur 0.1%)
from the Ravva Oil fields of
Andhra Pradesh)
3. Imported Crude (through
Heldia and Miri Crude) higher
then 0.5% Sulpher content

3. CDU Unit
consists of the
following
Sections
 Crude Preheat
 Desalter
 Fired Heater
 Crude Distillation Section
 Stripper
 Stabilizer
 Naphtha Splitter
 LPG Wash Section

5. Crude Distillation and Strippers
 Height of column: about 50m
 Number of trays: 38-45
 Feed from fired heater enters under try 5
 Pressure is maintained at 1.3-1.8 kg/cm2.
 Products-
 Distillate
 Bottom Products or residue to DCU

6. Stabilizer
 Column has 30 trays
 Top Temperature: 65°c
 Top pressure: 10kg/cm2
 The purpose of the stabilizer is to
stabilize naphtha by separating out
liquefied petroleum gas (LPG) and
other C-4 components.
 The fractionate of lower column or
Kero II is used as heating medium
for stabilizer reboiler.
 LPG withdrawn from Stabilizer reflux
drum is first washed with caustic and
then with water which is then sent to
storage.

7. Function of Tray in a Distillation

8. Naphtha Splitter
 The stabilized naphtha is further spit into light naphtha (50-110°c) and heavy
naphtha (110-180°c) in Spitter-I
 Splitter-I bottom is further split into reformer feed naphtha (110-150°c) and Kero-I
components.
 Reboiler heating media for Splitter-II is reduced crude oil from mail fractionator
column bottom.

9. THANK YOU