This document provides information about Gaurav Singh's 4-week summer training at Indian Oil Corporation Ltd in Panipat from June 1-28, 2017. It includes an acknowledgement of those who helped facilitate the training and an outline of topics to be covered in the full training report such as information about IOCL, descriptions of various units like the Crude Distillation Unit, and the objective of the training experience.

1. SUMMER TRAINING REPORT
Indian oil Corporation Ltd, Panipat
Duration: 01/06/2017 - 28/06/2017
Submitted to: Submitted by:
Miss Sangeeta Singh Gaurav Singh
Training & Development Department, 1405251018
IOCL
In partial fulfilment of requirements for the degree of
BACHELOR OF TECHNOLOGY
IN
CHEMICAL ENGINEERING
INSTITUTE OF ENGINEERING AND TECHNOLOGY,
LUCKNOW

2. PREFACE
Industrial training plays a vital role in the progress of future engineers. Not only does it
provide insights about the future concerned, it also bridges the gap between theory and
practical knowledge. I was fortunate that I was provided with an opportunity of undergoing
industrial training at INDIAN OIL CORPORATION LTD. Panipat. The experience gained
during this short period was fascinating to say the least. It was a tremendous feeling to
observe the operation of different units and processes. It was overwhelming for us to notice
how such a big refinery is being monitored and operated with proper coordination to achieve
desired results. During my training I realised that in order to be a successful chemical
engineer one needs to put his/her concepts into action. Thus, I hope that this training serves as
a stepping stone for me in future and help me carve a niche for myself in this field.

3. ACKNOWLEDGEMENT
My indebtedness and gratitude to the many individuals who have helped to shape this report
in its present form cannot be adequately conveyed in just a few sentences. Yet I must record
my immense gratitude to those who helped me undergo this valuable learning at IOCL
panipat.
I am highly obliged to Training and Development Department for providing me this
opportunity to learn at IOCL. I have further more to thank the officers of production for
sharing their knowledge about the plant and production process. It is really great opportunity
for me by which I have learned here many practical knowledge which are usually hard to find
in textbooks.
My special thanks to –
Mr Anupam Das (PNM)
Mr. Ajay kaila (PNM)
Mr. Radhakant Sharma (AM- L&D)
Miss Sangeeta Sinha (M- L&D))

4. TABLE OF CONTENT
1. Preface
2. Acknowledgement
3. About IOCL
4. Vision
5. Refineries
6. Pipelines
7. Mega units of IOCL, Panipat
8. Crude oil distillation (CDU)
9. Distillation (AVU&VDU)
10. Diesel Hydrodesulphurization (DHDS) / Hydrotreating (DHDT)
11. Delayed Coker Unit (DCU)
12. Project Objective
13. Bibliography

5. 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. 1,87,948 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,
IndianOil 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.

6. 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 operates 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 9.5
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 6,500 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.

7. VISION
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.

8. Refineries
 Digboi Refinery
The 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 1,70,000 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 expected 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.

9.  Barauni Refinery
Barauni Refinery in the Bihar state of India was built in collaboration with the Soviet
Union at a cost of Rs.49.4 crores and went on stream in July, 1964. The initial capacity of
1 MMTPA was expanded to 3 MMTPA by 1969. The present capacity of this refinery is
6.100 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
The 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 MMTPA.
 Panipat Refinery
Indian Oil Company's (IOC) seventh refinery is located at Panipat, 125km from Delhi, in
the state of Haryana in northern 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.

10. 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
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 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.
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
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 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.

11. IOCL Pipelines
IOCL operates a network of about 12848 km long crude oil, petroleum product and gas
pipilines.
Map for IOCL Pipelines throughout the country.

12. Mega units of IOCL, Panipat
 Paraxylene/Purified Terepthalic Acid (PX/PTA), Panipat
 Naphtha Cracker Plant, Panipat (PNC)
 Panipat refinery expansion (PRE)
 Paraxylene/Purified Terepthalic Acid (PX/PTA), 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/PTA) complex was built at a cost of Rs. 5,104 crore within the Panipat Refinery in
Haryana.
The PTA 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.
The Paraxylene plant is designed to process 5,00,000 MTPA of heart-cut Naphtha to produce
about 3,60,000 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 5,53,000 MTPA of Purified Terephthalic Acid from Paraxylene

13.  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, 125,000 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.

14.  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 mid-2006.
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 first 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 Rs11.3bn in improving the quality of petrol processed at the refinery.

15. CRUDE OIL DISTILLATION (CDU)
INTRODUCTION
Refining of crude oils or petroleum essentially consists of primary separation processes and
secondary conversion processes. The petroleum refining process is the separation of the
different hydrocarbons present in the crude oil into useful fractions and the conversion of
some of the 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 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.
PRETREATMENT OF CRUDE OILS
Crude oil comes from the ground, which contains variety of substances like gases, water, dirt
(minerals) etc. Pretreatment of the crude oil is important if the crude oil is to be transported
effectively and to be processed without causing fouling and 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 /or finely dispersed water.
OLEOPHILIC IMPURITIES: Oleophilic impurities are soluble and are sulphur
compounds, organometallic compounds, Ni, V, Fe and As etc., naphthenic acids and nitrogen
compounds.
Pre-treatment of the crude oil removes the oleophobic impurities.

16. PRETREATMENT TAKES PLACE IN TWO WAYS:
 Field separation
 Crude desalting
Field separation is the first step to remove the gases, water and dirt that accompany crude oil
coming from the ground and is located in the field near the site of the oil wells.
The field separator is often no more than a large vessel, which 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
separator 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 10-200
ppb, earlier 10-20 ppb were considered satisfactorily low. However, many refiners now aim
at 5 ppb 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.
Crude oil is heated up to 135-141oC in the train of heat exchanger operating in two parallel
section. The 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 40 ppb. 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 processes: forming emulsion of crude and water and
demulsification in which emulsion is broken by means of electric field and demulsifying
chemicals. Desalting is carried out 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 the salts
dissolved in the water and solution are separated from the crude by means of electrostatic
separating in a large vessel.
Operating Variables in Desalter: Some of the variables in the desalter operation are crude
charge rate, temperature, pressure, mixing valve pressure drop and wash water rate,
temperature, and quality, desalting voltage. Crude oil temperature charged to the desalter is
very important for the efficient operation of desalter. Lower temperature reduces desalting

17. 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 pressure which result in
hazardous condition, erratic operation and a loss of desalting efficiency
CRUDE OIL DESALTING

18. 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 producing 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

19. Various Streams From Atmospheric And Vacuum Distillation Column
ATMOSPHERIC COLUMN
Various steps in atmospheric crude oil distillation are -
 Preheating of Desalted crude
 Preflash
 Distillation
 Stabilization of Naphtha

20. 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. The preheated crude from the preheater
section is further heated and partially vaporized in the 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 the 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. The 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),atmospheric residue.
 Unstabilized Naphtha consists of LPG, naphtha and light gases (C-5 115C)
Intermediate Naphtha (Bombay High) (135oC) 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

21. 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. The reduced crude
oil from atmospheric column at about 360oC is heated and partially vaporized in the furnace.
The temperature in the flash zone of the tower is controlled by the furnace coil outlet
temperature. The 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 the 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 .

22. 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 on Performance of crude distillation is given in Table on the
next page.
Effect of Crude Characteristics on Performance of crude distillation

23. Diesel Hydrodesulphurization (DHDS) / Hydrotreating (DHDT)
Technology
In view of growing importance of Hydro processing, and to achieve leadership in developing,
adopting and assimilating state-of-the-art technology for competitive advantage, Indian Oil-
R&D initiated a systematic program to build 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
performance monitoring. Indian Oil-R&D in association with EIL (Engineers India Limited)
developed 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 bed reactor at temperature of 290-400°C and
pressure of 35-125 bar. The main chemical reactions in DHDS/DHDT are
hydrodesulphurization (HDS), hydrodenitrification (HDN), and aromatic and olefin
saturation. These reactions are carried on bi-functional catalysts. Reactor effluent is separated
into gas and liquid in a separator. Gas is recycled back to the 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

24. 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 vaporizes the residual oil and initiates cracking of the long chain hydrocarbon
molecules of the residual oil into hydrocarbon gases, Coker naphtha, 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 product coke is
subsequently removed. The 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 the 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 petroleum coke and some produce 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 about 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 such 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 temperatures as high as
about 1,200 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 description 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.

25. 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 °C. Thermal cracking begins in the pipe between the furnace and the coke drums,
and finishes in the coke drum that is on-stream. The 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 vapours 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.

26. 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 is 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 then quenched with water to cool it. The top
and bottom heads of the full coke drum are removed, and the solid petroleum coke is then cut
from the coke drum with a high pressure water nozzle, where it falls into a pit, pad, or
sluiceway for reclamation to storage.
PFD of DCU

27. PROJECT OBJECTIVE
 To draw flow sheet of plant and note the Temperature and Pressure
of streams from DCS.
FLOW SHEET OF DCU

28.  To balance material in the de-ethaniser unit
A UNSTABALISED NAPTHA
B TREATED GAS
C RECONTACT NAPTHA
D ABSORBER BOTTOM
E STRIPPER OVERHEAD
F STRIPPER BOTTOM
G OVERHEAD VAPOUR
Entering Leaving
Element A B C Total
entering
D E F G Total
leaving
H2O 39 0 3.3 42.3 0 38.97 0.03 3.3 42.3
H2S 3003.33 395.15 19.03 3417.51 212.07 2691.81 311.48 202.11 3417.47
H2 2.88 152.93 0.01 155.82 2.36 0 0 150.58 152.94
CO2 124.06 317.19 0.5 441.75 90.16 124.04 0.03 227.52 441.75
Methane 730.27 5954.02 3.32 6687.61 550.7 730.31 0 5406.60 6687.61
Ethylene 269.28 743.5 1.07 1013.85 197.5 269.24 0.06 547.05 1013.85
Ethane 3497 7375.2 12.54 10884.74 2537.51 3484.87 12.34 4850.07 10885.02
Propylene 1962.99 1582.99 11.11 3557.09 1323.62 726.37 1236.64 270.45 3557.08
Propane 4622.34 3257 31.1 7910.44 2962.14 1433.19 3189.17 325.94 7910.44
i-Butane 568.74 171.53 33.92 774.19 191.79 70.31 498.42 13.96 772.88
1-Butene 2086.12 525.69 159.43 2771.51 631.75 217.19 1868.91 53.64 2771.49
n-Butane 2304.24 518.96 306.16 3129.36 733.72 213.32 2090.89 91.39 3129.32
C5(120 C) 61261.7 1624.76 48168.64 111054 48276.04 715.38 60545.2 1517.38 111054
C5(140 C) 4782.1 52.76 13094.23 17929.01 3085.76 26.51 14333.5 61.24 17506.98
C5(170 C) 0 7.54 4603.45 4611.73 4603.45 3.97 9.28 0 4616.7
C5(520 C) 0 0 0 0 0 0 0 0 0
Conclusion
The total feed (material) entering into the system is equal to the product going
out of the system hence mass is conserved.

29.  To balance energy of de-ethaniser unit
A UNSTABALISED NAPTHA
B TREATED GAS
C RECONTACT NAPTHA
D ABSORBER BOTTOM
E STRIPPER OVERHEAD
F STRIPPER BOTTOM
G OVERHEAD VAPOUR
H ABSORBER INTERCOOLER DRAW
HE1 RECYCLE FROM HEAT EXCHANGER
HE2 RECYCLE FROM HEAT EXCHANGER
Enthalpy balance of de-ethaniser unit
Conclusion
The amount of energy coming into the system is equal to amount of energy leaving since
there is no energy generation within the system,
stream Flowrate Enthaply Heat Enter Stream Flowrate Enthalpy Heat Leave
A 99614 21.54 2145686 34128955 D 75399 25.16 1897039 33124832
B 22680 94.98 2154146 E 10748 109.55 1177443
C 66450 20.09 1334981 F 88865 93.37 8297325
HE-1 119393 105.07 12544623 G 13731 34.27 1294421
HE-2 126312 110.51 13958739 HE-1 119393 73.44 8768222
HE-2 125312 93.37 11700381
m Cp delt
H 71308 0.531 9 340780.9
Lean
amine
110000 1 15 1650000

30. CASE STUDY
A steam generator is producing 15tonn/hr of steam by recovering the heat
from HCGO, now after a change in arrangment of apparatus the same
steam generator is producing 4tonn/hr of steam.
Find the process where rest heat recoved from HCGO is used and also
write the energy balance equation for the same.
Solution
Case 1 -
When 15tonn of steam was produced .
BFW entering at 111 degree C and HCGO is entering at 290 degree C. and at outlet MP
steam is produced which is at 263 degree C and HCGO leaving the reactor at 230 degree C.
Energy balance equation-
( M * Cp * delta T )of BFW + heat of vapourisation of BFW = ( M * Cp * delta T)of HCGO
+ waste
 15000*2.82*(263-111) + 15000*461.74 = 348905*0.734*(290-230) + waste
 13344600 = 14085294 + energy wasted
Case 2-
When VR is heated with HCGO and rest heat is recovered by producing 4tonn/hr steam by
steam generation
HCGO is entering ar 290 degreeC in a HE with VR at 159 degreeC, VR is heated upto 202
degreeC and HCGO comes out at 260 degreeC and then send to steam generator at 230
degreeC where it produces 4tonn/hr of steam and HCGO comes out at 214 degreeC final
temp

31. Energy balance equation-
( M * Cp * delta T)of HCGO + ( M * Cp * delta T)of HCGO =
(M * Cp * delta T)of VR+ ( M * Cp * delta T )of BFW + heat of vapourisation of BFW +
energy wasted
 348905*0.734*(290-260) + 348605*0.734*(230-214) =
300000*0.569*(202-159) + 4000*2.82*(263-111) + 4000*461 + energy waste
 11780428.42 = 10557260 + waste
Result
The energy from HCGO which was used to produce 15tonn/hr steam is now used to preheat
VR and to produce 4tonn/hr of steam

32. BIBLIOGHRAPHY
1. IOCL UNIT MANUAL
2. WWW.IOCL.COM
3. WWW.WIKIPEDIA.COM