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Summer Training
Report On
Atmospheric and
Vaccum Unit
(From 17th June 2013 to 12th July 2013)
Submitted By:
Priyanka Singh
B.tech (3rd year ),
Chemical Engg.
Anand Engg. College,
Agra
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Acknowledgement
I am very thankful to all those honorable people who were involved in guiding me throughout my
venture as it was their valuable experience and knowledge that I was able to complete my
training with ease and satisfaction.
I would like to express sincere gratitude to my Institute, Anand Engg. College,Agra and
Indian Oil Corporation, which provided me with an opportunity to achieve my goal.
I am thankful to Mr. Kuldeep Kumar Baldia, Officer(T&D), Mathura Refinery who believed
in our ability and allowed us to undergo vocational training in Mathura Refinery.
My heartfelt thanks to Mr. Pramod Kumar , Chief Production Manager, Mathura Refineryfor their proper guidance throughout my training.
I also express my sincere and heartfelt thanks to Mr. Samiullah, (Mgr.VBU), Mr.A.K.Gautam
(Mgr. AVU) , Mathura Refinery for their dedicated guidance, constant encouragement and
valuable time throughout the training duration.
The assistance and moral encouragement received from my family is gratefully acknowledged.
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Purpose of vocational training
As per the All India Council of Technical Education (AICTE), a governing body for technica
education in India, norms B-Tech (Bachelor of Technology) is a professional course which
comprises of four years of study of the various Engineering subjects of the particular discipline
In theory, we learn about various machines without knowing them actually i.e. we can only knowhow the parts of machines functions. But when it comes for identifying of machines we remain a
the back foot. Further, the processes, mechanisms, which we are studying are of conventiona
nature, i.e. these are the basics to do a particular thing, produce items, etc. Due to increased
demand, calling of better product quality, the industries have adopted unconventional type o
processes to which we are not familiar. So, in order to visualize a thing in complex productio
system, we need to go through he basics of an industry, their way of working, identification o
equipment by just looking, etc.
Thus the purpose of vocational training is to:
Identify the equipment by just looking at them.
To know about the working of critical equipments.
To understand the working of equipments which we have already studied or yet to study.
Be familiar with the system, production, maintenance, inspection e.t.c.
Know how the basics are utilized to manipulate the production processes & system along
with the equipments.
The purpose of vocational training is NOT the mastering of whole system since it is very
difficult to know each & every thing about a particular industry & its complex processes.
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S. No Name of topic Page No.
1. Introduction 1
2. Historical Overview 33. Description of Mathura Refinery 4
4. Fire and Safety 5
5. Block Diagram of refinery 6
6. Glossary of commonly used words 7
7. Old Unit
Purpose and description of Old Unit
Structure of Old Unit
Process Flow Chart of Old Unit
Atmospheric & Vacuum Distillation Unit (AVU)
Vis-breaker Unit (VBU)
Continuous Catalytic Reforming Unit (CCRU)
Fluid Catalytic cracking Unit (FCCU)
Merox Unit
9 - 27
9
10
11
18
21
24
27
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INTRODUCTION
Refinery is a plant that basically refines the crude oil into the various kinds of petroleum product
(finished).The crude oil is the raw material foe this plant and it is purchased from the othe
countries and from the parts in our country as well.
The crude oil in Mathura Refinery comes from Bombay High which is th
chief source of crude oil in the Indian subcontinent. It is transported from there to Okha (the
outermost part of India near the sea in Gujarat) by ships. It is then stirred in tanks which are
located in that re region. This crude oil is then transported from Salaya (village in Okha) t
Mathura Refinery by means of Salaya-Mathura Pipeline. This work is undertaken by pipelin
departments.
Thus Indian Oil Corporation Limited (abbreviated as IOCL)
Is basically a joint collaboration of Refinery & pipelines. The Refinery is totally concerned
with this production, marketing of petroleum products while the pipeline department has nothing
to do with the production departments & is involved in transportation of crude oil.
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Historical Overview
IOCL has been a largest producer of petroleum products fromcrude oil & is public sector government undertakin
organization. In the past, where there were only thee majo
producers of petroleum products in namely IOCL, BPCL &
HPCL. The IOCL alone had a credit of producing about 70% o
the total consumption while BPCL about 28% at that time. Then
at that time quality was not so important for the IOCL as th
consumers has to buy the products either it is good or bad due to
non-availability of other sources. Further, there was n
competition in this sector and the primary motive was to produc
more & more without bothering the quality.
But, as the time changed, the private sector had
also come into existence thus increasing the competition in th
market.eg Reliance Oil Refinery. This called for better produc
quality at a considerable low cost. Now, in order to maintain it
existence in the market, IOCL had undergone several changes to ensure better quality. They had
spent a lot of money in installing highly modern plants equipped with world class machinery.
They are trying to stick to the prescribed quality standards and have maintained
various departments e.g., Inspection dept., fire & safety dept., Inventory & materials dept., etc
Today, IOCL is the major producer of petroleum products in India.
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Mathura Refinery is an ISO: 9001 Organization and isinvolved in refining of crude oil into various forms of
useful petroleum products. It is spreaded over an area of
about 40sq.km and is well connected by means of rail &
road. It is built under the No Flying Zone. It is among th
top 100 Oil refineries in the world.
Crude being processed at mathura refinery are as
follows:
1. Low sulphur crudes : Indian (Bombay high)Nigerian (Qua Iboe)
2. High sulphur crudes : Saudi Arabian,Arab medium
The crude oil is supplied to Mathura Refinery by Salaya
Mathura Pipeline from Okha, to where it comes from
Bombay High by means of ships. This after bein
converted into petroleum products is sent into different regions of the country. It distributes on it
own in U.P & other adjacent states. One distribution station is at Bharatpur & other a
Jalandhar.The oil to Jalandhar is transported through pipeline known as MJPL pipeline (Mathura
Jalandhar Pipeline).This distribution is also made through the Railways. Mathura Refinery also
owns a residential colony for its workers as Mathura refinery Nagar. It is located at distance o
5km towards Mathura from the Mathura Refinery, both being on the NH-2(Agra-Delh
Highway).Mathura Refinery Nagar has a lush green sprawling area.
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Block Diagram of Refinery.
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Glossary of commonly used words.
CDU Crude Distillation Unit.
LPG Liquefied Petroleum Gas
SKO Super Kerosene Oil
ATF Air Turbine Fuel
FO Furnace Oil
LDO Light Diesel Oil
HSD High Speed Diesel
MS Motor Spirit / Petrol / GasolineDCU Delayed coking Unit
HCU Hydrogen Cracking Unit
FCCU Fluidized Catalytic-Cracking
Process
VBU Vis Breaking Unit
RPC Refined Petroleum Coke
SRU Sulphur Recovery Unit
BTU Bitumen treating UnitPRU Propylene Recovery Unit
AU Atmospheric Unit
AVU Atmospheric Vacuum Unit
VDU Vacuum Distillation Unit
VGO Vacuum Gaseous Oil
RCO Residuum Crude Oil
CRU Catalytic Reforming Unit
LLDPE Linear Low Density
Polyethylene
HDPE High Density Polyethylene,
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Key
1. AVU- Atmospheric Vacuum Unit
2. VDU- Vacuum Distillation Unit
3. CDU- Crude Distillation Unit
4. CCRU- Continuous Catalyst Reformer Unit
5. FCCU- Fluidized Catalyst Cracking Unit6. PRU- Propylene Reformer Unit
7. VBU- Viscosity Breaker Unit
8. MEROX- For The Recovery Of LPG
9. BITUMIN UNIT- For The Recovery Of Bitumen (Coal-Tar)
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Key
1. HN- Heavy Naphtha
2. ATF- Aviation Turbine Fuel
3. HK- Heavy Kerosene
4. LGO- Light Gas Oil
5. HGO- Heavy Gas Oil
6. RCO- Residual Crude Oil7. LVGO- Light Vacuum Gas Oil
8. LDO- Light Diesel Oil
9. HVGO- Heavy Vacuum Gas Oil
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ATMOSPHERIC & VACUUM DISTILLATION UNIT (AVU)
PROCESS FLOW DESCRIPTION:
Atmospheric Distillation Process.
1. FEED SUPPLY:
Crude oil is stored in 8 tanks .Two tanks are having a capacity of 65000 m 3 & other six tanks ar
having a capacity of 50000 m3 each respectively. Booster pumps located in the off site area wil
take suction from any one tank & deliver into the suction unit feed pumps. Normally three of the
four pumps are working.
2. FEED PREHEAT TRAIN-1:
The crude feed pump charges crude oil into desalter through a series of shell & tube exchanger
in the preheat train where it is heated to the desalter temperature. Crude oil in train-1 i
distributed into three parallel streams & passes through the exchangers where it is heated by the
product streams on the shell side. Then the three streams combine to give an average temperatur
of the feed.
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3. DESALTER:
The desalter is an electrostatic coaleser to purify the crude from sediments & corrosion inducing
salts & thereby reduce fouling & corrosion of the distillation equipments. Sediments contain fin
particles of sand, clay, rust etc. salt are generally sodium, magnesium, calcium & chlorides. Som
traces of carbonates & sulphates are also present. Desalter pressure is maintained at 11-12kg/cm2.Small quantity of water is added in the desalter. A high voltage is applied so tha
ionisation of the salts takes place & they get dissolved in the water. Sediments also settle down &
are removed with the brine. The brine is cooled in the air & water coolers before final disposal.
4. CRUDE PREHEAT TRAIN-2:
Desalted crude is pumped through a series of heat exchangers (shell & tube type) where it i
heated to the pre fractionator temperature by the products in the shell side. Crude in the preheatrain-2 is divided into three parallel streams where it get heated in a series of exchangers &
finally combines to give a average stream temperature of 180 C-190C. The combined stream i
fed to the pre fractionator.
5. PRE FRACTIONATOR:
The pre fractionator column is provided to unload the load on the crude charge heater as well a
the crude column. The IBP-100C-110C cut naphtha is recovered from the crude oil in the pr
fractionator column as the overhead product where as the bottom product is sent for furthe
processing. Thus the pre fractionator helps in increasing the capacity of the plant & helps insaving energy. Medium pressure steam is sent in the column to strip of the lighter products &
which helps in carrying the lighter end products.
Column temperature:
Bottom : 174 C-180 C
Top : 114 C-120 C
Column pressure:
Bottom : 2.2-2.8 kg/cm
2
Top : 1.8-2.4 kg/cm2
The overhead products are condensed in air & water coolers & collected in the reflux drum.A
part of the collected product is sent as reflux & rest is sent to the stabilizer. Heavy naphtha is also
sent to the stabiliser from the atmospheric column. The stabilised naphtha is sent as feed to the
CCRU.
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6. CRUDE PRE HEAT TRAIN-3:
The bottom product of the pre fractionator is pumped into the train-3.The stream is split into thre
streams with the help of flow controllers & passes into a series of heat exchangers where it is pr
heated before entering the furnace. The stream combines before entering the furnace to give a
average stream temperature of around 250 C
7. CRUDE FIRED HEATERS:
The furnace used in the AVU is a balanced draft furnace. The preheated crude is further heated &
partially vaporised in the four no. of parallel tubular heaters. Each heater is a box type vertica
furnace with up-firing burners (14 no. in each furnace) provided on the floor with processing fue
oil & fuel gas firing. Crude is passed in each furnace in four passes provided with control valveat the crude oil inlet to heater coils.
Like the other conventional heaters, this furnace also has two zones (i) convection zone &
(ii) Radiation zone. There are eight rows each having eight tube in the convection zone. There ar
eighty four tubes arranged vertically in the radiation zone with twenty one tubes from each pass
The feed enters the convection zone, gets heated by the flue gases. Then it passes into th
radiation zone for further heating. The maximum skin temperature goes up to 550C.The fue
entering is atomized using medium pressure steam for better burning of the fuel. The air provide
for burning is preheated using the flue gases, thus saving heat.
8. CRUDE DISTILLATION SECTION:
Crude oil stream combines at the outlet of the furnaces into one stream & enters the flash zone o
the column. The atmospheric column is divided into three sections. The column height is abou
67 metres. The top & bottom section of the column is about 5.5 metres in diameter& middle
portion is 6.4 metres in diameter. The trays in the column are replaced by the packed bed t
increase the contact time of vapours. To insure complete recovery of the lighter hydrocarbons th
bottom of the tower is charged with superheated medium pressure steam produced in the furnaceThe feed enters at a temperature of around 350 C.
Gasoline/light naphtha vapours & water vapours are withdrawn from the top of the column
passes through the air coolers & the condensate gets collected in the reflux drum. Water i
drained from the bottom. Apart of the reflux is sent to the column as reflux to maintain th
temperature & rest is routed for the removal of H2S& mercaptans in other units.
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Heavy Naphtha cut is withdrawn from the fourth tray enters the stripper. Superheated steam i
introduced at the bottom of the stripper which helps in removing the lighter products coming with
it. The stripped off vapours re-enter the column. The bottom of the stripper is then pumped by th
pump via heat exchangers & air coolers to the run-down diesel, naphtha from the stabilizer or t
the storage tanks.
ATF is withdrawn from the chimney tray below the ATF packing is sent to the side stripperSuperheated stripping steam is provided to strip of the light vapours which re enter the column
above the packing & bottom of the stripper is pumped via heat exchangers & air coolers to th
storage tanks. Apart of the ATF is provided as the circulating reflux to maintain the temperature
& reduce the vapour load.
Heavy kerosene is withdrawn from the HK packing & sent to the side stripper. The stripped
kerosene is pumped via pumps through the heat exchangers & air coolers to the coaleser to
remove the water. The kerosene from the coaleser is sent to the storage tanks. The vapours from
the stripper enter the column at the top of the packing. A reflux stream is also provided tomaintain the column temperature.
Light Gas oil (LGO) is withdrawn below the LGO packing & enters the stripper. The stripped of
vapours enter the column above the packing & the bottom is pumped via pumps through a serie
of heat exchangers & air coolers to the coaleser which helps in removing the water. The LGO
from the top of the coaleser is sent to the HSD storage with the other diesel component A
circulating reflux is also provided to maintain the column temperature.
Heavy gas oil (HGO) is withdrawn below the HGO packing & enters the stripper. The stripped
off vapours enter the column & bottom is sent via pumps through the heat exchangers to thstorage tanks. Reflux stream is also provided in the same way.
The residue left in the column bottom known as the atmospheric residue is sent as feed to th
vacuum distillation unit.
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10. VACUUM DISTILLATION SECTION:
Vacuum Distillation Process
The feed to the vacuum column is the atmospheric residue. It enters the column at a temperatur
of 350 C after being heated in the vacuum fired heater. The operating pressure is about 60-64
mm of Hg at the top of the column & 90-94 mm of Hg at the bottom. The feed rate to the column
must not exceed 575 m3//h. Vacuum is maintained in the column to reduce the boiling point othe products.
Water vapour & a small amount of lighter hydrocarbons produced by cracking are sent to the top
of the vacuum tower & condensed in the overhead condensers.
The first side cut Light vacuum gas oil (LVGO cut
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part of it is sent to the column reflux & rest is sent to the run down tanks which is further used a
feed for the FCCU.
The left over is the vacuum residue. A part of it is sent as bitumen feed & rest is sent as feed to
the vis-breaker unit.
10. STABILISATION SECTION:
Gasoline from the stabiliser feed accumulator is transferred by pumps through a series of hea
exchangers to the stabiliser column having 37 trays. The overhead vapours is mainly LPG are
condensed in air coolers & collected in the reflux drum.A part is sent as reflux to the column top
& rest is routed to the merox unit. The stabilised gasoline from the column bottom is sent as feed
to the CRU.
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