Vocational Summer Training
Indian Oil Corporation L.T.D, &Petrochemical Panipat
Duration- 17/06/2019 to 26/07/2019
BACHELOR OF TECHNOLOGY IN CHEMICAL ENGINEERING
CHEMICAL ENGINEERING DEPARTMENT, DCRUST MURTHAL
Submitted By
SIDDHARTH ROHILLA
ROLL NO. 16001005040
AVU-II( ATMOSPHERIC VACCUM
DISTILLATION UNIT)
❖ INTRODUCTION:-
⮚ The main purpose of this unit is to separate the raw crude into different fractions
depending on their difference in volatility i.e boiling point difference.
⮚ The capacity of crude handling for panipat refinery was commissioned with 6.0 MMTPA in
May 1998 and revamped to 7.5 MMTPA in October 2010.
⮚ AVU is called a mother unit as it provides feed to other secondary units like hydrogen
unit, CRU, HCU, FCC, Bitumen unit and VBU.
BLOCK DIAGRAM OF CRUDE DESALTING
Diagram of a fired heater
⮚ It a balance draft type heater which has two forced draft fans and one induced draft fan.
⮚ Atomising steam is used here in order to disperse fuel oil into small molecules so that its
burning will be easy and at a faster rate.
⮚ Air from environment forced through draft fans into air preheater where the get preheated
and then used into heater.
⮚ Flue gases from heater is cooled into airpreheater and then thorugh induced draft passed to
stack and then to the environment.
⮚ AIRPREHEATER:-
1. The upper section consists of cast iron and lower section with glass.
2. Main purpose is to exchange the heat between the flue gases coming from CDU heater
and air coming from forced draft fans.
VACUUM DISTILLATION UNIT
⮚ Pressure : 60-70 mmHg
⮚ Diameter : greater than CDU
⮚ 5 beds in Enriching section
⮚ 6trays in Stripping section
⮚ Vacuum created by Steam Ejectors
⮚ The main products are:
i. Vacuum Diesel
ii. Light Gas Oil
iii. Heavy Gas Oil
iv. Vacuum slops
v. Vacuum residue
STEAM EJECTORS
⮚ The steam is passed with a high velocity through nozzle and vacuum is created
⮚ Gases from VDU top are carried along with steam
⮚ According to Bernoulli’s theorem,the Pressure in II must be less than that in I but
actually the pressure is more due to shock waves which are supersonic.This region is
called sonic boost
⮚ P/g+v2/2g+z=constant
⮚ In Region III,the pressure increases due to decrease in velocity .
Hot Well
⮚ The steam from steam ejectors is sent to a condensor
⮚ From there,it goes to hot well through barometric leg
⮚ In Hot well ,gases are separated from steam condensate on the basis of density
difference.
⮚ The off gases are sent to CDU heater
⮚ The sour water is sent to Sour Water Stripping Unit(SWSU)
⮚ Slop oil is sent to rundown line.
PERCENTAGE YIELD OF PRODUCTS
PRODUCT % YIELD
Liquefied Petroleum 1.05
Gas
Light Naphtha 10.2
Heavy Naphtha 5.29
Kerosene 10.8
Light Gas Oil 15.09
Heavy Gas Oil 3.14
Vacuum Diesel 3.09
Vacuum Gas Oil 23.7
Vacuum Residue 28.99
TYPES OF REFLUX
⮚ Circulating Reflux(Pump around Reflux
/CR) - Hot liquid stream from lower tray
are condensed in reflux drum and sent to
the upper tray.Its used to control the
temperature of the column.
⮚ Internal Reflux(Pump back Reflux/IR)
Liquid from the top tray is introduced to the
bottom tray.Its used to enhance the purity of
products.
ANALYSIS OF PRODUCTS
⮚ Flash Point-
Minimum temperature at which the vapors of oil sample give a momentary flash on
application of standard flame.
⮚ LPG weathering-
Temperature at which 5% of the volume is left after 100 ml LPG is taken in a
weathering pot.
⮚ Vacuum Diesel Recovery-
The amount of vacuum diesel vaporised after 100ml of it is heated upto 360◦C.
⮚ Vacuum Residue Penetration(PEN)-
The depth upto which a needle penetrates into a cube of vacuum residue
⮚ Distillation-
Initial (5%)and Final Boiling Point(95%) of the product is determined
THANKS
