WINTER TRAINING REPORT

IndianOiI
INDIAN OIL CORPORATION LIMITED
(PANIPAT REFINERY)

DURATION:- 03/01/2022 - 01/02/2022

NATIONAL INSTITUTE OF TECHNOLOGY AGARTALA

Submitted
T
B. Tech, S/h Semester, 3rdTear
Chemica/EngineeringDepartment

Guided By:-
Mr. Saranga Bora
•
 PREFACE
The knowledge of any subject is incomplete until it is done practically.
Chemical & Petrochemical particularly requires a thorough knowledge of
practical training for a comprehensive understanding. The progress is certainly
based on the formation of desired product from Crude Oil.

The requirement of oil products in different sectors from households to

industrial requirement has grown tremendously over the last few decades and
day-by-day new technologies are being added to this evergrowing vast field.
The young Engineers and field scholars must be appreciated for their training
and fieldwork. This report describes the work carried out by me during one
month internship at Indian Oil Corporation Limited, (Panipat Refinery).

During this period, I have understood a lot of things related to the working of
a refinery in its different divisions under Chemical & Petrochemical
Department. This has developed a sense of confidence in me.

I Perceives as this opportunity as a big milestone in my career development.

This internship is proved to be a good practical experience and has also
enhanced my technical knowledge. A lot of credit goes to my instructors who
helped me all theway from the very beginning.
 ACKNOWLEDGEMENT
The internship opportunity I had with IOCL Panipat was a great chance
for learning and gaining practical knowledge. Therefore, I consider
myself as a very lucky individual as I was provided with an opportunity to
be a part of it. I am also grateful for having a chance to meet so many
wonderful people and professionals who led me through this internship
period.

I would like to acknowledge my profound and sincere gratitude to Mr.

Saranga Bora for his careful and precious guidance which were extremely
valuable for my study both theoretically and practically. I offer thanks and
gratitude to him for the responds who extended so earnestly his co-operation
answering thequeries on time and helping me in the internship period.

I perceive as this opportunity as a big milestone in my career development.

I will strive to use gained skills and knowledge in the best possible way and
I will continue to work on their improvement, in order to attain desired
career objectives.

PARUL GHUNAWAT
B. Tech, 5th Semester, 3rd Year
Chemical Engineering Department
National Institute of Technology Agartala
 TABLE OF CONTENTS

1. Preface
2. Acknowledgement
3. Indian Oil Corporation Ltd (The Energy of India)
4. Vision & Values of Indian oil corporation Limited
5. IOCL ,Pipelines & Refineries through out India
6. Mega Units of IOCL, Panipat
7. Fire & Safety Department of Indian oil corporation Ltd
8. Crude oil Distillation Unit (CDU)
9. Distillation (AVU & VDU)
10.Diesel Hydrodesulphurization (DHDS)/Hydrotreating (DHDT)
11.Delayed Coker Unit (DCU)
12.Project (Opportunity Crude Processing, Benefits and challenges)
13.Biblography
 About IOCL

Indian Oil Corporation (Indian Oil) is India's largest commercial enterprise, with a sales
turnover of Rs. 4,38.710 crore (USD 65,391 million) and profits of Rs. 19,106 crore (USD
2,848 million) for the year 2016-17. The improvement in operational and financial performance
for FY 2016-17 reflected in the market capitalization Of the Company, which grew two-fold,
from Rs. 95.564 crore as on 31st March 2016 to Rs. crore as on 31st March 2017. In view of
its rising share price and market capitalisation, Indian Oil was included in the Nifty50 index
(NSE benchmark index of 50 best performing corporates). Indian Oil is ranked 161st among
the world's largest corporates (and first among Indian enterprises) in the prestigious Fortune
•Global 500' listing for the year 2016,

As India's flagship national oil company, with a 33,000-strong work-force currently, indian oil
has been meeting India's energy demands for over half a century. With a corporate vision to be
The Energy of India' and to become 'A globally admired company,' IndianOil's business
interests straddle the entire hydrocarbon value-chain — from refining, pipeline transportation
and marketing of petroleum products to exploration & production of crude oil & gas. marketing
Of natural gas and petrochemicals. besides forays into alternative energy and globalisation of
downstream operations.

Having set up subsidiaries in Sri Lanka, Mauritius and the UAE, the Corporation is
simultaneously scouting for new business opportunities in the energy markets of Asia and
Africa. It has also formed about 20 joint ventures with reputed business partners from India
and abroad to pursue diverse business interests.
 INDIAN OIL (ENERGY OF INDIA)

Indian Oil accounts for nearly half of India's petroleum products market share, 35% national
refining capacity (together with its subsidiary Chennai Petroleum Corporation Ltd.. or CPCL),
and 71% downstream sector pipelines through capacity. The Indian Oil Group owns and
0perates 11 of India's 23 refineries with a combined refining capacity of 80.7 MMTPA
(million metric tonnes per annum).

The Corporation's cross-country pipelines network. for transportation of crude oil to refineries
and finished products to high-demand centres, spans about 12,848 km. With a throughput
capacity of 93.7 MMTPA for crude oil and petroleum products and 95 MMSCMD for gas.
this network meets the vital energy needs of the consumers in an efficient, economical and
environment-friendly manner.

The Corporation has a portfolio of leading energy brands that includes Indane LPG cooking
gas, SERVO lubricants, XTRAPREMIUM petrol, XTRAMILE diesel. PROPEL
petrochemicals. etc. Besides Indian Oil, both SERVO and Indane have earned the coveted
Super brand status.

Countrywide Reach
Indian Oil's network of over 46,000 customer touch-points reaches petroleum products to
every nook and corner of the country. These include more than 26,000 petrol & diesel stations,
including 6,565 Kisan Seva Kendra outlets (KSKs) in the rural markets. Over 10,000 fuel
stations across the country are now fully automated.

The Corporation has a 65% share of the bulk consumer business, and almost dedicated pumps
are in operation for the convenience of large-volume consumers like the defence services,
railways and state transport undertakings, ensuring products and inventory at their doorstep.
They are backed for supplies by 129 bulk storage terminals and depots, 101 aviation fuel
stations and 91 LPG bottling plants.
 VISION
Ethics

the
creatNity
research

VALUES
Care • Innovation • Passion • Trust

Indian Oil's 'Vision with Values' encompasses the Corporation's new aspirations — to broaden
its horizons, to expand across new vistas, and to infuse new-age dynamism among its
employees.

Adopted in the company's Golden Jubilee year (2009), as a 'shared vision' Of Indian Oil People
and other stakeholders, it is a matrix of six cornerstones that would together facilitate the
Corporation's endeavours to be 'The Energy of India' and to become 'A globally admired
company. '
More importantly, the Vision is infused with the core values of Care, Innovation. Passion and
Trust, which embody the collective conscience of the company and its people, and have helped
it to grow and achieve new heights of success year after year.
 Refineries

Digboi Refinery
Ihe Digboi Refinery was set up at Digboi in 1901 by Assam Oil Company Ltd. The Indian
Oil Corporation Ltd (IOC) took over the refinery and marketing management of Assam Oil
Company Ltd. with effect from 1981 and created a separate division. This division has both
refinery and marketing operations. The refinery at Digboi had an installed capacity 0.50
MMTPA (million metric tonnes per annum). The refining capacity of the refinery was
increased to 0.65 MMTPA by modernization of refinery in July. 1996. A new delayed Coking
Unit of 1.70000 TPA capacity was commissioned in 1999. A new Solvent Dewaxing Unit
for maximizing production of microcrystalline wax was installed and commissioned in 2003.
The refinery has also installed Hydrotreater-UOP in 2002 to improve the quality of diesel-
The MSQ Upgradation unit has been commissioned. A new terminal with state of the art
facility is under construction and to be completed by 2016.

Guwahati Refinery (Assam)

The Gujarat Refinery is an oil refinery located at Koyali (Near Vadodara) in Gujarat. Western
India. It is the Second largest refinery owned by India Oil Corporation after Panipat Refinery.
The refinery is currently under projected expansion to 18 MMTPA.

Haldia Refinery
The Haldia Refinery for processing 2.5 MMTPA of Middle East crude was commissioned
in January, 1975 with two sectors - one for producing fuel products and the other for Lube
base stocks.

Gujarat Refinery
The Gujarat Refinery is an oil refinery located at Koyali (Near Vadodara) in Gujarat. Western
India. It is the Second largest refinery owned by Indian Oil Corporation after Panipat
Refinery. The refinery is currently under projected expansion to 18 MMTPA.

Barauni Refinery
Barauni Refinery in the Bihar state of India was built in collaboration with the Soviet Union
at a cost of Rs.49.4crores and went on stream in July. 1964. "The initial capacity of I
MMTPA was expanded to 3 MMTPA by 1969. The present capacity of this refinery is
MMTPA. A Catalytic Reformer Unit (CRU) was also added to the refinery in 1997 for
production of unleaded motor spirit. Projects are also planned for meeting future fuel quality
requirements.
 Bongaigaon Refinery
Bongaigaon Refinery is an oil refinery and petrochemical complex located at
Bongaigaon in Assam. It was announced in 1969 and construction began in 1972.

Paradip Refinery
Paradip refinery is the 11th_refinery_being set up by Indian Oil Corporation in_Paradip
town in the state of Odisha. The installed capacity of refinery was 15 MMTPA.

Mathura Refinery
Mathura Refinery. owned by Indian Oil Corporation, is located in Mathura, Uttar
Pradesh. The refinery processes low sulphur crude from Bombay High. imported low
sulphur crude from Nigeria. and high sulphur crude from the Middle East.
The refinery, which cost Rs.253.92 crores to build, was commissioned in January, 1982.
Construction began on the refinery in October 1972. The foundation stone was laid by Indira
Gandhi, the former prime minister of India. The FCCU and Sulphur Recovery Units were
commissioned in January, 1983. The refining capacity of this refinery was expanded to 7.5
MMTPA in 1989 by debottlenecking and revamping. A DHDS Unit was commissioned in
1989 for production of HSD with low sulphur content of 0.25% wt. (max.). 'The present
refining capacity of this refinery is 8.00 N'IMTPA.

Panipat Refinery
Indian Oil Company's (IOC) seventh refinery is located at Panipat, 125km from Delhi. in
the state of Haryana in northem India. The main units of the facility are a once-through
hydrocracker (OHCU), a residual fluid catalytic cracker and a continuous catalytic reformer
unit, as well as other secondary treatment units,
The 6mmpta Panipat refinery was constructed and commissioned in 1998 with an
investment of Rs38.68bn, which included the costs of marketing and pipeline installations.
The refinery capacity was expanded to 12mmtpa in 2006. The capacity was further
expanded to 15mmtpa in November 2010.

The Panipat refinery is the most technically advanced public sector refinery in India. It
supplies petroleum products to the state Of Haryana and the north-west region including
Punjab, Chandigarh, Himachal, Uttaranchal, Jammu & Kashmir, Rajasthan and Delhi.

In September 2008. IOC announced its plan to expand the Panipat oil refinery's capacity to
15mtpa with an investment of Rs8,060m; however, the cost of expansion increased to
R.s10.07bn- Earlier, around Rs41.65bn was invested by the company to increase the
refinery's capacity to 12mtpa. The expansion project was commissioned in mid-2006.

The 15mtpa expanded units were commissioned in November 2010. The expansion required
closure of the plant, for 40 to 45 days. The project revamped the capacities of the crude and
vacuum distillation units, OHCU and the delayed coking unit. In addition, second-stage
reactors were installed in the diesel hydrotreating unit of the refinery.

In September 2008. IOC announced its plan to expand the Panipat oil refinery's capacity to
15mtpa with an investment of Rs8.060 m however, the cost Of expansion increased to
Rs10.07bn. Earlier. around Rs41.65bn was invested by the company to increase the
refinery's capacity to 12mtpa. The expansion project was commissioned in mid-2006.

The 15mtpa expanded units were commissioned in November 2010. The expansion required
closure of the plant. for 40 to 45 days. The project revamped the capacities of the crude and
vacuum distillation units, OHCU and the delayed coking unit. In addition, second-stage
reactors were installed in the diesel hydrotreating unit of the refinery.
 IOCL Pipelines
IOCL operates a network of about 12848 km long crude oil, petroleum product and gas
pipelines.

Map for IOCL Pipelines throughout the country.

 Mega units of IOCL, Panipat
Paraxylene/Purified Terepthalic Acid (PX/PTA), Panipat
Naphtha Cracker Plant, Panipat (PNC)
Panipat refinery expansion (PRE)

ParaxyIene/Purified Terepthalic Acid (PX/ITA), Panipat

The most technologically advanced plant in the country, the PX/PTA plant marks Indian Oil's
major step towards forward integration in the hydrocarbon value chain by manufacturing
Paraxylene (PX) from captive Naphtha and thereafter, converting it into Purified Terephthalic
Acid (PTA). The integrated Paraxylene/Purified Terephthallic Acid (PX/14A) complex was built
at a cost of R.s. 5, 104 crore within the Panipat Refinery in Haryana.

The Plant is the single largest unit in India with a world-scale capacity of 5.53.000 MTPA.
achieving economy of scale. The process package for the PTA plant was prepared by erstwhile
M/S Dupont, UK (now M/S. Invista) and that of the Paraxylene Unit was prepared by M/S UOP.
USA. M/S EIL and M/S Toyo Engineering were the Project Management Consultants (PMC) for
executing the PTA and PX respectively.
Paraxylene plant is designed to process MTPA of heart-cut Naphtha to produce about MTPA
of PX. Naphtha is sourced from Indian Oil's Panipat and Mathura refineries, for which Naphtha
splitter units are set up at the respective refineries. The PTA unit produces MTPA of Purified
Terephthalic Acid from Paraxylene
Naphtha Cracker Plant(PNC), Panipat

The world-class Naphtha Cracker at Panipat, built at a cost of Rs 14,400 crore, is the largest
operating cracker capacity in India.
The feed for the unit is sourced internally from Indian Oil's Koyali. Panipat and Mathura
refineries. The Naphtha Cracker comprises of the following downstream units Polypropylene
(capacity: 600,000 tonnes), High Density Polyethylene (HDPE) (dedicated capacity: 300,000
tonnes) and Linear Low Density Poly Ethylene (LLDPE) (350,000 tonnes Swing unit with
HDPE). Mono Ethylene Glycol (MEG) plant (capacity: 325,000 tonnes).

The cracker will produce over 800,000 tonnes per annum of ethylene. 600,000 tonnes per annum
of Propylene. tonnes per annum of Benzene, and other products viz., LPG, Pyrolysis Fuel Oil.
components of Gasoline and Diesel.

The Polypropylene (PP) unit is designed to produce high quality and high value niche grades
including high speed Bi-axially Oriented Polypropylene (BOPP) (used for food packaging and
laminations). high clarity random co-polymers (used for food containers and thin walled
products) and super impact co-polymer grades (used for batteries, automobile parts, luggage and
heavy duty transport containers). Polyethylene is used for making injection moulded caps. heavy
duty crates, containers. bins. textile bobbins, luggage ware, thermoware, storage bins, pressure
pipes (for gas and water), small blow-moulded bottles, jerry cans. etc.
Panipat refinery expansion(PRE)

In September 2008. IOC announced its plan to expand the Panipat oil refinery's capacity to
15mtpa with an investment of Rs8,060 m: however, the cost of expansion increased to
Rs10.07bn. Earlier, around Rs41.65bn was invested by the company to increase the refinery'S
capacity to 12mtpa. The expansion project was commissioned in

The 15mtpa expanded units were commissioned in November 2010. The expansion required
50% closure of the plant, for 40 to 45 days. The project revamped the capacities of the crude
and vacuum distillation units. OHCU and the delayed coking unit. In addition, second-stage
reactors were installed in the diesel hydrotreating unit of the refinery.

The main secondary processing units at the refinery include a residual fluidised catalytic
cracking unit, a bitumen blowing unit, a catalytic reforming unit, a hydrocracker unit, a
visbreaker unit, a sulphur block and other auxiliary facilities.

For the fust time in India, a fast-track project implementation method called Lump sum Turn
Key was adopted to meet the stringent time schedule for supply of low sulphur diesel

The quality of diesel at the refinery was improved by commissioning a diesel hydro
desulphurisation unit in 1999. The process of desulphurisation through the DHDS enables the
reduction of sulphur content in diesel, resulting in positive environmental protection results in
the control of automotive emissions.

The Panipat refinery is known for producing high quality, environmentally friendly petroleum
products. and has developed a new import substitute. 96 RON petrol. IOC is also investing RAS
11.3bn in improving the quality of petrol processed at the refinery.
 Fire & Safe!! Department
Fire is a chemical reaction in which heat is generated and it is called
"Combustion". Fire results from the combination of fuel combustible materials,
heat and oxygen. The Temperature at which fuel catche fire is called "Ignition
temperature" and it depends upon the properties of materials.

COMMON CAUSE OF FIRE IN THE REFINERIES

Sources Example Safe Measures
Electric Equipment Sensors, wiring, switches Use proper equipments
Friction Moving Parts Regular monitoring
Open Flames Blow lamps, welding Precaution measures
Auto Ignition Hot Vapour Liquid in air Prevent leakage Steam
FIRE PROTECTION IN THE REFINERY
- Fire Station.
- Foam chamber connection to storage tanks
- Fire water mains.
- Fire monitors.
- Fire water sprinkler system.
-Fire water storage tank
- Fire Water booster pumps.
- Fire fighting steam points.
- Automatic CO, installation.
- Dry riser.
- Fire siren.
- Fire Alarm system.
 Methods of Extinguishment

DIFFERENT FIRE EXTINGUISHING AGENT

Water
Mechanical Foam
Dry chemical powder
Carbon Dioxide
foam)
Steam
-Vaporising Liquid
or
eonOustibIemateri•l
Blanketing

STARVATION
 CRUDE OIL DISTILLATION (CDU)

INTRODUCI'ION
Refining Of crude Oils or petroleum essentially consists Of primary and secondary conversion
processes. The petroleum refining is the separation of the different hydrocrarbons present in
the crude oil into useful fraction and the conversion of some of hydrocarbons into products
having higher quality performance. Atmospheric and vacuum distillation of crude oils is the
main primary separation processes producing various straight run products, e.g., gasoline to
lube oil/vacuum gas oils (VGO). These products, particularly the light and middle distillates.
gasoline. kerosene and diesel are more in demand than their direct availability from crude oils,
all over the world.

PRETREATMENT OF CRUDE OILS

Crud & oil comes from the ground. which contains variety of substances like gases. water. dirt
(minerals) etc. Pretreatment of the cruck oil is important if the crude & oil is to be transported
effectively and to be processed without causing fouling corrosion in the subsequent operation
starting from distillation, catalytic reforming and secondary conversion processes.

IMPURITIES Impurities in the crude oil are either oleophobic or oleophilic

OLEOPHOBIC IMPURITIES: oleophobic impurities include & salt, mainly chloride &
impurities of Na, K, Ca& Mg, sediments such as salt, sand, mud, iron oxide, iron sulphide
etc. and water present as soluble emulsified and finely dispersed water.

OLEOPHILIC IMPURITIES: Oleophllic impurities soluble are sulphur compounds,

organometallic compounds Ni. V, Fe As etc„ naphthenic acids and nitrogen compounds.

Pre-treatment of the crude oil removes the oleophobic impurities.

 PREI'REATMENT TAKES PLACE IN TWO WAYS:

:- field separation

:-Crude desalting

Field separation- is first step to remove the gases. water and dirt that accompany crude oil
coming from the ground and is located in field near the site of the oil wells.

The field separation is often no more than a large vessel. gives a quieting zone to permit gravity
separation of three phases: gases. crude oil and water (with entrained dirt).

Crude Desalting - is a water washing Operation performed at the refinery site to get additional
crude oil clean up.

Crude Oil Desalting consists of

Purifying "process
Remove salts, inorganic particles and residual water from crude oil
Reduces corrosion and fouling

Desalting Process -is used for removal of the salts. like chlorides of calcium,
magnesium and sodium and other impurities as these are corrosive in nature. The crude oil
coming from field separation will continue to have some water/brine and dirt entrained with it.
Water washing removes much of the water-soluble minerals and entrained solids (impurities).
There are two types of desalting: single & multistage desalting. Commercial crudes, salt contents
10-20 earlier 10-20ppb were considered satisfactorily low. However, many refiners now aim at
5ppb or less (1-2 ppb) which is not possible through single stage desalting; hence two Stage
desalting is required.

Desalting process consists of three main stages: heating, mixing and settling.

Cruck oil is heated up to 135-141 oc in the train of heat exchanger in two parallel section.
temperature in desalting is maintained by operating bypass valve of heat exchanger. Single stage
desalting with water recycle is usually justified if salt Content in crude is less than 40ppb. Two
stage desalting involves dehydration followed by desalting. Double stage desalting is better for
residuum hydrotreating. Fuel oil quality is better. Desalting process is two stage forming
emulsion of crude and water and demulsification in which emulsion is broken by means of
electric field and demulsifying chemicals. desalting is carried by emulsifying the crude& oil and
then separating the salt dissolved in water. Two phases water/oil is separated either by using
chemicals to break down the emulsion or by passing high potential electric current. By injecting
water salts dissolved in the water and solution are separated from the crude by means of
electrostatic separating in a large vessel

Operating Variable in desalter -Some of the variables in the desalter operation are crude charge
rate. Temperature, pressure. mixing valve pressure drop and water rate, temperature. and quality,
desalting voltage. Crude oil temperature charged to desalter is very important for the efficient
operation of desalter. Lower temperature reduces desalting efficiency because of increased
viscosity of oil while higher temperature reduces desalting efficiency due to greater electrical
conductivity of the crude. Pressure in the vessel must be maintained at a high value to avoid
vaporization of crude oil which result in hazardous condition, erratic operation and a loss of
desalting efficiency
CRUDE OIL DESALTING
 CRUDE DISTILLATION UNIT
Crude Oil from tanks is pumped from tanks into Heat Exchanger
Network for heating and then fed to desalter to remove salts of calcium
and magnesium and metals (which accelerate deactivation of catalyst).
Crude Oil is further heated and fed Atmospheric Distillation Unit
column to from which different products are removed. Light products
are removed from top and heavy products are removed from the bottom.
Crude distillation column does not have just top and bottom products;
they also have a number of side products as well. First crude oil is
heated in Heat Exchanger Train and Furnace and then fed to the column
at the flash zone.

Since the pressure in furnace is high and the pressure inside column is
low, when the feed is fed to the column it flashes into vapour and
liquid parts.
If no side product is withdrawn and all the vapour are withdrawn from
top of the column, then a huge condenser is required to condense all the
vapour along with huge amount of reflux drum. Cooling water
requirement also increases and load on cooling tower increase. Along
with this problem flooding also starts to occur at the top of column if no
side stream product is removed and efficiency of fractionation reduces.

When the vapour from top is condensed and fed back again then it is
called Top Reflux. When some side stream is taken out for cooling and
fed again into the column it is called Pumparound (Circulation
Reflux). Pumparound is done to remove heat from the column as to
reduce load on condenser and cooling tower. Side stream is withdrawn
from Drawoff Chimney Tray. When Chimney Tray has some holes on
them to
allow liquid to flow through them they are called Partial Draw-off
Chimney Tray. When no liquid is allowed to flow into the lower portion
through the Chimney Tray and all the liquid is withdrawn from the
Chimney Tray then some amount of liquid from the Pumparound liquid
is fed back again into the lower portion of the tray which is called
Internal Reflux.
Some liquid from Pumparound is removed and send to stripping
column from where side product is withdrawn after stripping using
steam.
Pumparound liquid is cooled with feed instead of cooling water and
cooling tower load reduces.
When all vapour are withdrawn from the top and cooled with cooling
water, then temperature of cooling water increases to a very high
temperature and decomposition of calcium carbonate in cooling water
takes place which leads to fouling of heat exchanger.
Important Function of Pumparound
l) Recovering heat using feed instead of cooling water which
increases load on cooling tower.
2) Suppress top tray flooding
3) Reduces cooling water outlet temperature which reduces calcium
carbonate decomposition.
When vapour and liquid comes in contact with each other on the tray
the more volatile component in liquid phase gain latent heat of
vaporisation and moves to liquid phase while less volatile liquid from
vapour phase loses heat of condensation and moves to liquid phase and
thus fractionation occurs.
PRODUCTS FROM CRUDE DISTILLATION
SHORT LONG CUT USAGE
s NAME NAME RANGE
No.
1. GAS Fuel Gas C1-C2 Internal Fuel
 2. LPG Liquefied C3-C4 Domestic/Auto Fuel
Petroleum
Gas
3. NAPH Naphtha C5 - MS Component

120
4. HN Heavy 120-150 HSD Component
Naphtha
5. KERO Kerosene 140-270 Domestic Fuel
6. ATF Aviation 140-240 Aeroplanes
Turbine Fuel
7. LGO Light Gas Oil 240/270- HSD/DHDS/DHDT
320 feed
8. HGO Heavy Gas 320-370 HSD/DHDS/DHDT
Oil feed
9. VD Vacuum 370 HSD/DHDS/DHDT
Diesel feed
10. LVGO Light 370-425 HSDDHDS/DHDT
Vacuum Gas feed
Oil
11. HVGO Heavy 425-550 HSD/DHDS/DHDT
Vacuum Gas feed
Oil
12. V. SLOP Vacuum Slop 550-560 IFO
Component/RFCCU
feed
13. VR Vacuum 560+ Bitumen/VBU
Residue fee/DCU fee/RFCCU
feed
C5— 90 NAPHTHA C5- HGU feed/1SOM
90 feed
CRUDE AND PRODUCT SPECIFICATION
Specification of Crude:
l) Gravity 30-40 oc API
2) Viscosity 3-24 Cst @ 36 oc
 (3) POUR POINT (-)30-(+)30 degree C
(4) RVP 0.34-0.67 kg/cm2
(5) Salt Content 156 ppm (max)
(6) BS&W 2.0% vol (max)
(7) Total Sulphur 0.17-2.35% wt
8) Wax Content 0.68-2.8% wt
Specification of Product:
1) LPG Confirm to IS-4576 to general and following
specifications in particular.

a) Vapour pressure @ 65 oc not to exceed

16.87 kg/cm2 (a)
b) Weathering 95% vol. minimum at 2 oc
and 760 mmHg pressure.
c) Not more than 1% of C5 components.
2) STABILISED NAPHTHA RVP not to exceed 0.7 kg/cm2 (a)
(3) HN Flash Point :> 15oc
Distillation : 120-140 oc

4) KERO Confirm to IS : 1459- 1974

FBP : 300 oc (max.)
Flash Point : 38 oc (min)
5) ATF Flash Point : 38 oc (min)
Freezing : (-) 50 oc (min)
Silver strip : Nil Corrosion.
Density @ : 0.775 to 0.84
6) MTO Confirm to BIS-1440 in general and to the
following specifications in particular.
ASTM D-86 IBP : 145 oc
FBP : 200 oc
 Flash Point : 38 oc
7) LGO Flash Point : 35 oc (min)
Pour Point : As per instruction.

8) HGO Flash Point : 35 oc (min.)

Pour Point: As per instruction
Recovery : 90% @360 oc
9) RCO
Flash Point : 150 oc
Density : As reported
Recovery : 10% at 370 oc

10) Vac. Diesel

Flash Point : >125 oc
Pour Point: (+6) to (+) 18 oc
Recovery : 90% @360 oc

11) LVGO CCR : 0.50 wt. % (max).

12) HVGO Pour Point : (+) 27 to (+) 42 oc
 DISTILLATION
Desalted crude flows to atmospheric and vacuum distillation through crude pre flashing
section. Atmospheric distillation column (ADU) and Vacuum distillation column (VDU) are
the main primary separation processes reducing various straight run products. e.g., gasoline
to lube oils/vacuum gas oils (VGO). These products, particularly the light and middle
distillates, i.e„ gasoline. kerosene and diesel are more in demand than their direct availability
from crude oils. all over the world-

Crude oil distillation consists Of atmospheric and vacuum distillation. The heavier fraction
of crude oil obtained from atmospheric column requires high temperature. In order to avoid
cracking at higher temperature the heavier fraction are fractionated under vacuum. Typical
flow diagram of crude Oil distillation is given in Figure. Various Streams from Atmospheric
and Vacuum Distillation Column is given in Table below
 Various Streams From Atmospheric And Vacuum Distillation Column
Column Fraction Temperature Carbon Uses
range
Atmospheric Fuel Gases >40 C1-C2 Fuel
column LPG C3-C4 Domestic fuel
Straight run 20-90 C6-C10 Gasoline pool
gasoline
Naphtha (Medium 130-180 C6-C10 Catalytic reforming
and heavy) and aromatic plant
feed stock
Steam cracker,
synthesis
manufacture
KEROSENE 150-270 Cll-12 Aviation turbine
fuel. Domestic fuel.
LAB feed stock
(paraffin source
Light gas oil 230-320 C13-C17 High Speed diesel
component
Heavy gas oil 320-380 C18-C25 High speed diesel
component
Vacuum Light vacuum oil 370-425 C18-C25 Feed to FCC/HCC
column
Heavy vacuum 425-550 C26C38 Feed to FCC/HCC
Oil
Vacuum slop 550-560 RFCCU feed
Vacuum Residue >560 >C38 Bitumen/ Visbreaker
feed

ATMOSPHERIC COLUMN
Various steps in atmospheric crude Oil distillation are -
Preheating of Desalted crude
Preflash
Distillation
Stabilization of Naphtha
The desalted crude oil from the second stage desalting process is heated in two parallel heat
exchanger. The preheated crude having temperature Of about 180 C is goes to pre flash drum
Where about 3-4percent of light ends are removed. preheated crude& from the section is
further heated and partially vaporized in furnace containing tubular heater. the furnace has
two zones: radiant section and convection section. The radiant zone forms the combustion
zone and contains the burners. In convection zone the crude is further heated (inside the tube)
by the hot flue gases from the radiant section.

Heated and partially vaporized crude from fired heaters enters the flash zone of the column
and fractionated in the atmospheric column. The distillation section consist Of overhead
section. heavy naphtha section. kerosene section. light gas oil section, heavy gas Oil section
and reduced crude section each section contains circulating reflux system.

Naphtha stabilizer, caustic wash and naphtha splitting section: The unstablished naphtha from
the atmospheric distillation column is pumped to the naphtha stabilizer section for separation
Of stabilized overhead vapours which is condensed to recover LPG which is treated in caustic
and amine treating unit. Ille stabilized naphtha is further separated into light, medium and
heavy naphtha.

PRODUCTS OF ADU:
Major product from atmospheric column are light gases and LPG. light naphtha, medium
naphtha, heavy naphtha. kerosene. gas Oil (diesel)residue.

Unstabilized Naphtha consists Of LPG, naphtha and light gases (C-S 1150 Intermediate
Naphtha (Bombay High) ( 135cC) Solvent Naphtha
Heavy Naphtha ( 130-150C) routed to diesel or naphtha.
Kero/ATF ( 140-270/250c)
Light Gas Oil (250/270-320c)
Heavy Gas Oil (320-380c)
Reduced Crude Oil

Major products separated in atmospheric column

Operating Variables in ADU unit are:
Furnace coil outlet temperature
Crude distillation Column top pressure and top temperature
Stripping Steam flow
Product withdrawal Temperatures
 VACUUM DISTILLATION COLUMN (VDU)
The bottom product also called reduced crude Oil. from the atmospheric column is
fractionated in the vacuum column. Reduced crude Oil is very heavy compared to crude Oil
distilling under pressure requires high temperature Distillation under vacuum permits
fractionation at lower temperature which avoid cracking of the reduced crude oil and coking
of the furnace tube. Vacuum is maintained using three stage steam ejector. reduced crude oil
from atmospheric column at about 3600C is heated and partially vaporized in the fumace.
The temperature in the flash zone of the tower is controlled by the furnace coil outlet
temperature. Ille preheated and partially vaporised reduced crude enters the flash zone Of
vacuum column where it is fractionated into various streams.

PRODUCTS FROM VDU:

Various products from VDU are Light gasoil, Heavy gas oil, light lube distillate, medium lube
distillate, and heavy lube distillate and vacuum column residue

OPERATING PRESSURE OF VACUUM COLUMN:

About 90-95 mm Hg at the top and
About 135-140 mm Hg at the bottom

CHEMICAL INJECTION SYSTEM:

Chemical injection system consist Of caustic injection and ammonia injection and use of
corrosion inhibitor. use of demulsifier, addition of trisodium phosphate in boiler feed water..
Corrosion in the atmospheric tower overhead system is a common phenomenon and the
problem is increasing with increasing use of the heavier crude oil. Corrosion is primarily due
to hydrogen chloride, which is produced by hydrolysis of chloride salts remaining after
desalting. Other sours of corrosion are naphthenic acid and hydrogen sulphide. High caustic
injection is to avoided as high caustic injection system may lead to fouling in vacuum and
visbreaker furnaces. ammonia injection is done to maintain the pH. Corrosion inhibitor in
kerosene and naphtha is required to combat the corrosion. De-emulsifier is used to demulsify
the water and crude emulsion. Trisodium phosphate is used to maintain pH and prevent
corrosion in the boiler drums
EFFECT OF CRUDE CHARACTERISTICS:
Crude oil characteristics plays important role in the product distribution, processing scheme and
quality Of product. Effect of Crude Characteristics on Performance of crude distillation. Effect of
Crude Characteristics Performance of crude distillation is given in Table on the next page.
 Characteristics Effect
API A Measure of “heaviness”or "lightness"
API =(141 S / density) - 131S
API > 30 Light Crude
API < 28 Heavy Crude
Viscosity A measure of resistance to flow and is important parameter
effective desalting and highly dependant on temperature. High
viscosity crudes need high temperatures for effective desalting.
Ihere is a limit for temperature In desalters.
UOP It is measure of parafinity vis-a-vis aromaticity of Cruck
K(Characterisation High UOP K is desired for high conversion in FCC
factor) High UOP K is &sired for high conversion in FCC
Aromatic molecules can not be cracked in FCC. They will simply
take ride through the plant
Total acid Total Acid Number : A measure of Naphthenic Acid contents in
number(TAN) Crude leads to corrosion in various sections of the unit Over I
known NA species are present in crude.
All Nap. Acids are corrosive. Latest research indicates that
TAN is a complete Corrxhion Index
TAN with 2.5 may corrode at higher rate than TAN with say 6
Detailed metallurgical reviews & monitoring rnechanism must
be put in place
BS&W BS&WBottom Sediments & Water is a measure of water. water
dissolved substances. mud. sand & sludge. Lower BS&W - the
Sediments & higher the reliability of Unit. BS&W is one of major minter for
Water corrosive nuterials in crude.

Sulfur Sulfur is a measure of "sourness" & "sweetness" of crude

passed onto products as much as regulations market
. It is rmoves in hydrotreaters by reacting with H2: and recovered
elemental Sulfur in sulphur recovery unit
S > 23 SourCrude. S < 2 Sweet Crude
Total salts Total salts A Measure of contaminant in Crude that will
cause overhead corrosion foul-up exchangers by settling &
scaling . It is removed in desalters washing settling
VGO metals VGO metals is a measure of metals content in VGO fraction Ni
& V are known poisions of VGO hydrotreter catalyst.
Metals in VGO are controlled by controlling wash rate in Slop
Wax section of vaccum column

EFFECT OF CRUDE CHARACTERISTICS ON PERFORMANCE OF CRUDE

DISTILLATION
 Diesel Hydrodesulphurization (DHDS) / Hydrotreating (DHDT)
Technology

In view Of growing importance of Hydro processing. and to leadership in developing, adopting

and assimilating state-of-the-art technology for competitive advantage, Indian Oil R&D initiated
a systematic program to up knowledge base in hydro processing technology. With this expertise.
Indian Oil R&D has become leader in providing technical services to the refineries in the key
areas Of process Optimization, troubleshooting and monitoring. Indian Oil-R&D in monitoring.
Indian oil in association with EIL (Engineers India Limited) developing its proprietary Diesel
Hydrodesulphurization (DHDS) Hydrotreating (DHDT) technology.

Process Description
In Diesel hydrodesulphurization/ hydrotreating process, diesel feed is mixed with recycle
Hydrogen over a catalyst bed in a trickle reactor at temperature of 290-400 c and pressure Of 35-
125 bar. main chemical reactions in DHDS/DHDT are hydrodesulphurization (HDS).
hydrodenitrification (HDN), and aromatic and olefin saturation. These reactor-b are carried on
bi-functional catalysts. Reactor effluent is separated into gas and liquid in a separator. Gas is
recycled back to reactor after amine wash along with make-up Hydrogen and liquid is sent to the
stripper for removal of light gases and H2S.

Advantages
Indigenous Process design& technology
Capable of producing ultra-low Sulphur meeting BS-IV diesel specifications Competitive
with foreign licensors
Proprietary DHDS/DHDT catalyst system so as to offer a complete package.
Design and Engineering experiences of EIL
 Delayed Coker Unit (DCU)

Delayed coking is one of the chemical engineering unit processes used in many petroleum
refineries. The main objective of the delayed coking unit is to convert low value residual products
to lighter products of higher value and to produce a coke product.

In brief. the process heats the residual oil from the vacuum distillation unit in a petroleum refinery
to its thermal cracking temperature in the heat transfer tubes of a furnace. This partially vaprizes
the residual oil and initiates cracking of the long chain hydrocarbon molecules of the residual oil
into hydrocarbon gases. Coker and Coker gas oil and petroleum coke. The heater effluent
discharges into very large vertical vessels (called "coke &drums" ) where the cracking reactions
continue to completion. forming solid petroleum coke which deposits out and accumulates in the
coke drums from which the products coke is subsequently removed. diagram below depicts a
delayed coking unit With four coke drums (two pairs of two drums). However. larger units may
have as many as eight drums (four pairs of two drums). each Of which may have diameters of up
to ten meters and overall heights of up to 43 meters.

The yield of coke from delayed coking process ranges from about 18 to 30 percent by weight Of
the feedstock residual Oil (currently 30 % depending the Composition of the feedstock and the
operating variables. Many refineries world-wide produce as much as 2000 to 3000 tons per day
of coke and some reduce even more. Globally. the total amount petroleum coke produced in 2010
was about 123,000.000 metric tons ( 123 Mt) and is expected to increase at an annual rate of
amount 5.6 percent.

Petroleum coke may also be produced in an Oil refinery unit process that utilizes fluidized bed
technology. However. there are very few such facilities in operation and the amount Of petroleum
coke produced via Sikh technology is virtually insignificant. Another type of coke. commonly
referred to as "metallurgical coke". is the solid carbonaceous material derived from the destructive
distillation of low-ash, low-sulphur bituminous coal. Volatile constituents of the coal are driven
off by baking in an airless oven at temperature high as about 1200 degrees Celsius (about 2,200
degrees Fahrenheit). Metallurgical coke is used as fuel and as a reducing agent in the iron and
steel manufacturing industries. the worldwide consumption of metallurgical coke was about
450,000,000 metric tons (450 Mt) in in 2010.

FLOW DIAGRAM AND PROCESS DESCRIPTION

The schematic process flow diagram and &scription in this section are based on a typical delayed
coking unit with two coke drums. However, as mentioned above. larger units may have as many
as four pairs Of drums (eight drums in total) as well as a furnace for each pair Of coke drums.
 1

Typical schematic Flow diagram

Process description Residual oil from the vacuum distillation unit (sometimes including
high-boiling Oils from Other sources within the refinery) is pumped into the bottom Of the
distillation column called the main fractionator. From there it is pumped, along with some
injected steam, into the fuel-fired furnace and heated to its thermal cracking temperature
of about 365 DC. Thermal cracking typing in the pipe between the furnace and the coke
drums. and finishes in the coke drum that is €Mi-stream. injected steam helps to minimize
the deposition Of coke within the furnace tubes. Pumping the incoming residual oil into the
bottom Of the main fractionator, rather than directly into the furnace, preheats the
residual oil by having it contact the hot vapours in the bottom of the fractionator. At the
same time, some of the hot various condense into a high boiling liquid which recycles back
into the furnace along with the hot residual oil.

As cracking takes place in the drum. gas oil and lighter components are generated as a
vapour phase and separate from the liquid and solids. The drum effluent is vapour (except
for any liquid or solids entrainment) and is directed to main fractionator where it is
separated into the desired boiling point fractions.
The solid coke. formed in the on-stream coke drum as the cracking reaction continues to
completion. is deposited and remains in the coke drum in a porous structure that allows flow
through the pores. Depending upon the overall coke drum cycle being used. a coke drum may
fill in 16 to 24 hours.

After the drum full of the solidified coke, the hot mixture from the furnace is switched to The
second drum. While the Second drum is filling. the full drum is steamed out to reduce the
hydrocarbon content of the petroleum coke, and quenched with water to cool it. top and bottom
heads of full coke drum are removed. and the solid Petroleum coke is then cut from coke drum
with a high pressure water nozzle. where it falls into a pit. pad. or
sluiceway for reclamation to storage.

PFD of DCU
 Opportunity Crude Processing Benefits and Challenges:-

The global refining industry is at a crossroads amid changing market conditions and
environmental legislation requirements. As profit margins decline due to rising oil prices and
weak demand, it is difficult for many refiners around the world to justify making additional
investments for refining hard-to-process, poor-quality, although less expensive, opportunity
crudes. These crudes generally include heavy sour grades, oil sands/bitumen, extra-heavy oil,
high-TAN (total acid number) crudes and oil shale. However, some refineries do justify the
investment; for instance, Marathon Petroleum's 106 000 b/d Detroit refinery in the US and
Repsol's 100 000 b/d Cartagena refinery in Spain. As a matter of fact, some refining watchers
believe that refineries without the capability to process opportunity crudes will lose out to
competitors in the long term.

Reasons for processing opportunity crudes

First, political upheaval in the Middle East and North Africa in early 2011 has sent a wake-up call
to refiners that crude diversity is key to business sustainability, as the lack of light sweet Libyan
crudes has hurt
Mediterranean refiners. Since many of the plants in the region are designed to process light sweet
oil, they have been forced to find similar grades, thereby driving up costs for crudes from the
North Sea and Nigeria and pressuring down margins in the region. Operators who have had to
make adjustments include Greek Hellenic Petroleum, Italian Saras and Austrian OMV.
Second, less sophisticated, light oil refineries are less competitive, prompting some refiners to
close down facilities, turn the plant into a terminal, or put it up for sale. Examples include
Sunoco's 150 000 b/d Eagle Point refinery in New Jersey, US, and 85 000 b/d Tulsa refinery in
Oklahoma, US, ConocoPhillips' 260 000 b/d Wilhelmshaven plant in Germany, Shell's 107 000
b/d Harburg complex in Germany and 80 000 b/d Gothenburg facility in Sweden, and Total's 137
000 b/d Dunkirk refinery in France. On the other hand, coking refineries processing Maya heavy
oil in the US Gulf Coast consistently outperform cracking refineries handling light sweet Brent
crude, based on historical data. Figure 1 compares Maya coking with Brent cracking margins
amidst crude price volatility from QI 2005 to QI 2011. Figure 1 is a good representation of
refining margin trends, since it covers the refining Golden Age in 2005—2007, the tremendous
downturn in late 2008—2009 due to demand destruction, and a gradual recovery since 2010.
Third, developing countries with significant populations and growth potential such as Brazil,
China and India continue to drive up global light oil demand for producing transportation fuels
despite increasing use of biofuels and higher vehicle fuel efficiency. The IEA sees global primary
energy demand, excluding biofuels, rising by 36% between 2008 and 2035, or an annual average
of 1.2%, with non-OECD countries making up 93% of the forecasted rise in energy consumption.
The consultancy FACTS sees Asian oil consumption at 38.1 million b/d by 2030, against 24.9
million b/d in 2009, with an average oil demand growth of 2.5% from 2011-2020 and 1.3% from
2021-2030.
A fourth reason to process opportunity crudes is that the ratio of reserves of heavy crude oil and natural
bitumen to conventional crude oil is around 5:1. China and India are already competing for the development
of oil sands and extra-heavy oil projects in Canada and Venezuela, respectively. Meanwhile, I-JS Gulf Coast
refiners are fighting for approval of the Keystone XL pipeline, which will send Canadian dilbit to the PADD
Ill region.

Securing supply of opportunity crudes is not the end-game

Without a doubt, arrangement of a steady supply of opportunity crudes is of paramount importance.
However, processing these crudes to maximise profit margins — by producing the "right" fuels to achieve
the highest possible revenues and at the same time reduce costs — represents the ultimate business
objective. It is not so straightforward, unfortunately, as fuel market dynamics have shifted and
environmental regulations have been tightening for the past few years.

There are many issues threatening the possibility of refining opportunity crudes. These include the Low
Carbon Fuel Standard (LCFS) and crude carbon intensity regulations, climate change (carbon cap-and-trade
and carbon tax) and refinery emissions legislation, biofuels competition and higher vehicle fuel efficiency,
lower residual fuel oil demand, refining business uncertainty in OECD nations, inherently higher processing
costs associated with opportunity because of fouling and corrosion problems, and competition from non-
conventional crudes, NG condensates, and shale oil.

On the other hand, many factors favour processing opportunity crudes, such as an increasing demand for
petroleum fuels, particularly in developing nations, expanding recoverable reserves of non-conventional
crudes, global dieselisation, rising propylene demand, higher coking margins versus cracking margins,
maintaining a competitive advantage, and sustainability strategies. Therefore, how can refiners take
advantage of the opportunities and at the same time alleviate the threats when processing opportunity
crudes?

Five major drivers enhancing profit margins

There are five major drivers identified to ensure profitability when processing opportunity crudes. The first
three drivers — namely, increasing distillate yield and quality, converting high-sulphur fuel oil into valuable
products such as diesel and gasoline, and boosting propylene production — contribute to revenues. On the
other hand, the latter two drivers — mitigating fouling and corrosion, and reducing carbon footprint —
help lower operating costs. The relation between the five drivers and the margins obtained from
processing opportunity crudes is shown in the following equation.
Increasing distillate yield and quality
Middle distillates, consisting of diesel/gasoil, jet fuel, kerosene and heating oil, are projected to collectively
comprise 45% of the global demand barrel by 2015, up from 35% in 2005. In its 2010 World Oil Outlook,
the IEA predicted that a rising its 2010 World Oil Outlook, the IEA predicted that a rising share of diesel
cars in developing nations will raise the volumes of diesel/gasoil by nearly 10 million b/d from 2009—2030.
Overall, global fuel consumption is clearly shifting towards middle distillates and light products, with 55%
growth for middle distillates and 32% for gasoline and naphtha.
Increasing supply of opportunity crudes
There are basically four types of crude available to refiners around the world. They are light-sweet (30-40
'API, <0.5 S), light-sour (30-40 'API, 0.5-1.5 S), heavy-sour (15-30 •API, 1.5-3.1 S) and extra-heavy (<15 OAPI
and 3 wt% S). HACs have a neutralisation number or total acid number (TAN) exceeding 0.5mg KOH.

HACs represent the fastest-growing segment of global oil production. California, Brazil, North Sea, Russia,
China, India and West Africa are known to supply HACs, Also, oil sands-derived syncrudes are deemed highly
acidic. Over half of the world's oil supply is heavy and sour. The trend of crude becoming heavier and more
sour will continue in the longer term despite new discoveries of light-sweet crudes in West Africa and the
Caspian Sea. Due to the lack of HAC and BOB processing capacity by many refineries and the need to
produce light products, high-quality crudes are often in high demand, resulting in abundant supply and
significant discounts for opportunity crudes.

As of late 2005, HACs were offered at a discount of $10/bbl. According to the IJS EIA, the spread between
relatively light-sweet Brent and heavier sour Mexican Maya had widened from $5/bbl in May 2002 to
$151bbl in May 2005 as the global production of light-sweet crude declined between 2000 and 2004, and
fuel sulphur spe.

Processing HACs and BOB

HACs, which have a high naphthenic acid concentration, can adversely impact refinery reliability and
operations with corrosion, desalter problems, fouling, catalyst poisoning, product degradation and
environmental discharges. Additionally, diesel produced from HACs has a low cetane number. There are
various ways of managing naphthenic acid corrosion, including:
-:Predicting the corrosion behaviour of crudes and their relative risk levels
-:Inspection and monitoring methods to identify specific areas that are at risk of naphthenic acid
corrosion and to verify that control methods are being used effectively -:Applying corrosion control
methods.

There are also alloys that appear to be even more corrosion resistant than existing favourites (for example,
316 SS and 317 SS). In the future, modifying or removing naphthenic acids will be accomplished via
neutralisation, decarboxylation, hydrotreating and extraction according to recent research and
development works.

A major concern with processing heavy crudes is blending and mixtures, since it is common for compatible
crudes, such as Louisiana Light-Sweet, West Texas Intermediate and Alaskan North Slope, from multiple
fields to be mixed in pipeline systems, since a lot of refineries are short on crude tankage. These crudes
have different compositions and there are economic penalties for that variance. Since there are
incompatibilities between the high-asphaltene crudes and the crudes, Asian refiners who often process
waxy crudes may have problems accepting heavy crudes from Canada and Venezuela. Aromatics/heavy
crudes are often separated from light-paraffnic crudes to avoid asphaltene precipitation.

Crude oil incompatibility and the precipitation of asphaltenes on the blending of crudes can lead to
catastrophic fouling and coking in the preheat train, resulting in net economic loss. Common problems are
stable water emulsions in the desalter, fouled preheat exchangers and/or coking in the pipestill fumace
tubes. Therefore, it is important to use the oil compatibility model and tests to predict the proportions and
order of blending of oils that will prevent incompatibility prior to the purchase and scheduling crudes.

No matter which resid conversion is selected, coke and sediment formation are often major concerns.
Furthermore, byproducts of a heavier carbonaceous nature will be produced and refiners have to find
outlets for these materials as part of their overall economic considerations. Most BOB upgrading
can be undertaken using combinations of separations (distillation or deasphalting), thermal
processing (coking or visbreaking), fluid catalytic cracking and hydroprocessing.cifications became
increasingly stringent.

Crude distillation
When crude blends get heavier, atmospheric and vacuum tower distillate cut points tend to suffer
due to the increasing difficulty of vapourisation. Therefore, changes can be made, such as increasing
the temperature and residue stripping efficiency, lowering the pressure and flash zone oil partial
pressure, and modifying the pumparounds. For the atmospheric unit, other key areas include the
oil preheat train and charge furnace, column internals and the metallurgy of the unit exposed to
higher sulphur and high TAN. For the vacuum towers, evaluations should be made regarding furnace
sizing and outlet temperature, decoking capability, wash-zone capacity and steam requirement if it
is a wet column. Deep-cut vacuum distillation via a revamp of the unit to cut deeper into the resid,
to make additional FCC or hydrocracker feed, is one of the first and most attractive options a refiner
should consider.
 BIBLIOGHRAPHY

1. IOCL UNIT MANUAL

2. WWW.IOCL.COM
3. "'WW.WIKIPEDIA.COM