trainig Report for iocl

VOCATIONAL

TRAINING REPORT

[11-JUNE-2012 TO 6-JULY-2012]

[BARAUNI REFINERY, INDIAN OIL CORPORATION LTD]

(IN HARMONY WITH NATURE)

ASHISH KUMAR JHA

S4, CHEM. ENGG.

IT. GGV (C.G.)

Vocational Training Report June July 2012

Page 1 of 30 Ashish Kumar Jha, B.Tech, CHEM, IT.GGV

ACKNOWLEDGEMENT

Before proceeding with the detail of the report, I thank the almighty God for making

my vocational training a successful one.

I would like to thank Mr. A.K.Biswas (CTRO) and Miss Madhushree Maji (STRO),

for letting me enjoy this experience of getting trained at Barauni Refinery, Indian Oil

Corporation Ltd. It has helped me fully and has grown up my knowledge. Besides, I would

like to thank the officials of Barauni Refinery, Indian Oil Corporation Ltd for providing me a

good environment and facilities to complete my training.

I am also thankful to technicians and field operators and other staff of training

department who spared their valuable time and took effort explaining the working of various

units of the plant. I am greatly thankful to for their co-operation. I was thoroughly guided by

them throughout my training .The information provided to me by them have helped me a lot

and would also help me in my long run too .The tremendous effort put by them have

motivated me and made me gain confidence in completing this report.

Ashish Kumar Jha

S4, CHEM. ENGG.

IT.GGV



CONTENT

Title Page No

Acknowledgement 1

Introduction 3

Fire & Safety 7

Catalytic Reforming Unit 10

Atmospheric Vacuum Unit I/II 17

Atmospheric Vacuum Unit III 25



CHAPTER 1

INTRODUCTION

Company History

The Indian Oil Corporation Ltd. operates as the largest company in India in terms of

turnover and is the only Indian company to rank in the Fortune "Global 500" listing. The oil

concern is administratively controlled by India's Ministry of Petroleum and Natural Gas, a

government entity that owns just over 90 percent of the firm. Since 1959, this refining,

marketing, and international trading company served the Indian state with the important task

of reducing India's dependence on foreign oil and thus conserving valuable foreign exchange.

That changed in April 2002, however, when the Indian government deregulated its petroleum

industry and ended Indian Oil's monopoly on crude oil imports. The firm owns and operates

seven of the 17 refineries in India, controlling nearly 40 percent of the country's refining

capacity.

Indian Oil Corporation Limited is India’s largest company by sales with a turnover of

Rs. 3,28,744crores($ 72,125 million) and profit of Rs. 7445 crores ($ 1,633 million) for the

year 2010-11.



Barauni Refinery

Barauni Refinery was built in collaboration with Russia and Romania.situated 125

kilometers from Patna, it was built with an initial cost of Rs. 49.40 crores. Barauni refinery

was commissioned in 1964 with a refining capacity of 1 million metric Tonnes per annum

and it was dedicated to Nation by then Union Minister for petroleum, Prof. Humayun Kabir

in January 1965. After De-bottlenecking, revamping and expansion projects, its capacity

today is 6 MMTPA. Matching secondary processing facilities such ResidFluidised Catalytic

Cracker (RFCC), Diesel Hydrotreating (DHDT), Sulphur Recovery Unit (SRU) have been

added.

Barauni refinery was initially designed to process low Sulphur Crude Oil (Sweet

Crude) of Assam. Hence sweet crude is being sourcedfrom African, South East Asian and

Middle East countries like Nigeria,Iraq,and Malaysia. The refinery receives crude oil by

pipeline from Paradeep on the eastern coast via Haldia.

Theses state of the art eco-friendly technologies have enabled the refinery to produce

environment- friendly green fuels complying with international standards.



Fig. Flow Sheet of Plant



Process Units

AVU-I : ATMOSPHERIC & VACUUM UNIT-1

AVU-II : ATMOSPHERIC & VACUUM UNIT-2

AVU-III : ATMOSPHERIC & VACUUM UNIT-3

PEU : PHENOL EXTRACTION UNIT

SDU : SOLVENT DEWAXING UNIT

CCU : COKE CALCINATION UNIT

NSU : NAPTHA SPLITTER UNIT

CRU : CATALYTIC REFORMER UNIT

RFCCU : RESID FLUID CATALYTIC CRACKING UNIT

DHDT : DIESEL HYDROTREATER UNIT

HGU : HYDROGEN GENERATION UNIT

SRU : SULPHUR RECOVERY UNIT

ARU : AMINE REGENERATION UNIT

SWS : SOUR WATER STRIPPER



CHAPTER 2

FIRE AND SAFETY DEPARTMENT

Fire safety refers to the precaution that are taken to prevent or reduce the likelihood of

a fire that may result in death, injury or property damage, alert those in a structure to the

presence of fire in the event one occurs, better enable those threatened by a fire to survive, or

to reduce the damage caused by a fire. Fire safety measures include those that are planned

during the construction of a building or implemented in structures that are already standing.

Threats to fire safety are referred to as fire hazards. A fire hazard may include a situation that

increases the likelihood a fire may start or may impede escape in the event a fire occurs.

Some common fire hazards are:

1. Electrical systems that are overload, resulting in hot wiring or connection.

2. Combustibles storage areas with insufficient protection.

3. Combustibles near equipment that generates heat, flame, or sparks.

4. Candles, Flammable liquids and Smoking (Cigarattes, cigars, etc).

5. Fireplace chimneys not properly or regularly cleaned.

6. Heating appliances – stoves, ovens, furnaces, boilers, heaters.

7. Electrical wiring in poor condition.

8. Batteries.



Barauni Refinery is very hazardous plant among all plants due to production of all

kinds of petroleum products that are highly inflammable. Therefore safety is very essential

for the refinery. It is the policy of the corporation that every reasonable effort shall be made

to provide and ensure safety inside the plant. To ensure safety and to have a safe workplace

the employees shall follow safety regulations that are made by Fire and Safety Department of

IOCL, Barauni Refinery.

Fire and Safety Plans

1. Key contact information

2. Utility services(including shut off valve for water, gas and electric)

3. Access issues

4. Dangerous stored materials

5. Location of people with special

6. Connection to sprinkler system

7. Layout, drawing and site plan of building

8. Maintenance schedule for life safety systems

9. Personal training and fire drill procedure

Safety Rules and Regulations:

1. Smoking in battery area is prohibited.



2. Taking matchsticks, lighter etc. inside the battery area are strictly prohibited.

3. Never work inside the plant without helmet in specific area.

4. Only flame proof safety torches/hand lamps tube used.

Safety in Petro Chemical Industry

Petro Chemical industry is a bulk business! This means that the output is huge, but the

number of processes, which are same worldwide, is rather low. Therefore, groups and

corporation have standardized their procedures and processes to a very high degree and

implemented their own safety rules and regulation. The aim is to identify the main toxic and

explosive substances arising during operations at an early stage thus reliably protecting man,

environment and equipment. Special safety requirements have to be considered in times of

shutdowns which are carried out on a regular basis. It is no surprise that operators of

refineries on all continents rely on dragger solution – some for several decades. Cleaning –

Distilling – Converting: in refineries these three processes utilized to produce main products

from crude oil, whereby the majority of the production is diesel, domestic fuel oil and

gasoline.



CHAPTER-3

CATALYTIC REFORMING UNIT(CRU)

Introduction

Catalytic reforming is a chemical process used to convert petroleum refinery

naphthas, typically having low octane ratings, into high-octane liquid products called

reformates which are components of high-octane gasoline (also known as high-octane petrol).

Basically, the process re-arranges or re-structures the hydrocarbon molecules in the naphtha

feedstocks as well as breaking some of the molecules into smaller molecules. The overall

effect is that the product reformate contains hydrocarbons with more complex molecular

shapes having higher octane values than the hydrocarbons in the naphtha feedstock. In so

doing, the process separates hydrogen atoms from the hydrocarbon molecules and produces

very significant amounts of byproduct hydrogen gas for use in a number of the other

processes involved in a modern petroleum refinery. Other byproducts are small amounts of

methane, ethane, propane, and butanes.

This process is quite different from and not to be confused with the catalytic steam

reforming process used industrially to produce various products such as hydrogen, ammonia,

and methanol from natural gas, naphtha or other petroleum-derived feedstocks. Nor is this

process to be confused with various other catalytic reforming processes that use methanol or

biomass-derived feedstocks to produce hydrogen for fuel cells or other uses.

Reaction Chemistry



There are many chemical reactions that occur in the catalytic reforming process, all of

which occur in the presence of a catalyst and a high partial pressure of hydrogen. Depending

upon the type or version of catalytic reforming used as well as the desired reaction severity,

the reaction conditions range from temperatures of about 495 to 525 °C and from pressures of

about 5 to 45 atm.

The commonly used catalytic reforming catalysts contain noble metals such as platinum

and/or rhenium, which are very susceptible to poisoning by sulfur and nitrogen compounds.

Therefore, the naphtha feedstock to a catalytic reformer is always pre-processed in a

hydrodesulfurization unit which removes both the sulfur and the nitrogen compounds.

The four major catalytic reforming reactions are:

1: The dehydrogenation of naphthenes to convert them into aromatics as exemplified in the

conversion methylcyclohexane (a naphthene) to toluene (an aromatic), as shown below:

2: The isomerization of normal paraffins to isoparaffins as exemplified in the conversion of

normal octane to 2,5-Dimethylhexane (an isoparaffin), as shown below:



3: The dehydrogenation and aromatization of paraffins to aromatics (commonly called

dehydrocyclization) as exemplified in the conversion of normal heptane to toluene, as shown

below:

4: The hydrocracking of paraffins into smaller molecules as exemplified by the cracking of

normal heptane into isopentane and ethane, as shown below:

The hydrocracking of paraffins is the only one of the above four major reforming

reactions that consumes hydrogen. The isomerization of normal paraffins does not consume

or produce hydrogen. However, both the dehydrogenation of naphthenes and the

dehydrocyclization of paraffins produce hydrogen. The overall net production of hydrogen in

the catalytic reforming of petroleum naphthas ranges from about 50 to 200 cubic meters of

hydrogen gas (at 0 °C and 1 atm) per cubic meter of liquid naphtha feedstock. In the United

States customary units, that is equivalent to 300 to 1200 cubic feet of hydrogen gas (at 60 °F

and 1 atm) per barrel of liquid naphtha feedstock. In many petroleum refineries, the net

hydrogen produced in catalytic reforming supplies a significant part of the hydrogen used



elsewhere in the refinery (for example, in hydrodesulfurization processes). The hydrogen is

also necessary in order to hydrogenolyze any polymers that form on the catalyst.

Process Description

The most commonly used type of catalytic reforming unit has three reactors, each

with a fixed bed of catalyst, and all of the catalyst is regenerated in situ during routine

catalyst regeneration shutdowns which occur approximately once each 6 to 24 months. Such

a unit is referred to as a semi-regenerative catalytic reformer (SRR).

Some catalytic reforming units have an extra spare or swing reactor and each reactor

can be individually isolated so that any one reactor can be undergoing in situ regeneration

while the other reactors are in operation. When that reactor is regenerated, it replaces another

reactor which, in turn, is isolated so that it can then be regenerated. Such units, referred to as

cyclic catalytic reformers, are not very common. Cyclic catalytic reformers serve to extend

the period between required shutdowns.

The latest and most modern type of catalytic reformers are called continuous catalyst

regeneration reformers (CCR). Such units are characterized by continuous in-situ

regeneration of part of the catalyst in a special regenerator, and by continuous addition of the

regenerated catalyst to the operating reactors. As of 2006, two CCR versions available:

UOP's CCR Platformer process and Axen's Octanizing process. The installation and use of

CCR units is rapidly increasing.

Many of the earliest catalytic reforming units (in the 1950s and 1960s) were non-

regenerative in that they did not perform in situ catalyst regeneration. Instead, when needed,

the aged catalyst was replaced by fresh catalyst and the aged catalyst was shipped to catalyst



manufacturers to be either regenerated or to recover the platinum content of the aged catalyst.

Very few, if any, catalytic reformers currently in operation are non-regenerative.

The process flow diagram below depicts a typical semi-regenerative catalytic reforming unit.

Fig. Schematic diagram of a typical semi-regenerative catalytic reformer unit in a

petroleum refinery

The liquid feed (at the bottom left in the diagram) is pumped up to the reaction

pressure (5 to 45 atm) and is joined by a stream of hydrogen-rich recycle gas. The resulting

liquid-gas mixture is preheated by flowing through a heat exchanger. The preheated feed

mixture is then totally vaporized and heated to the reaction temperature (495 to 520 °C)

before the vaporized reactants enter the first reactor. As the vaporized reactants flow through

the fixed bed of catalyst in the reactor, the major reaction is the dehydrogenation of

naphthenes to aromatics (as described earlier herein) which is highly endothermic and results

in a large temperature decrease between the inlet and outlet of the reactor. To maintain the



required reaction temperature and the rate of reaction, the vaporized stream is reheated in the

second fired heater before it flows through the second reactor. The temperature again

decreases across the second reactor and the vaporized stream must again be reheated in the

third fired heater before it flows through the third reactor. As the vaporized stream proceeds

through the three reactors, the reaction rates decrease and the reactors therefore become

larger. At the same time, the amount of reheat required between the reactors becomes

smaller. Usually, three reactors are all that is required to provide the desired performance of

the catalytic reforming unit.

Some installations use three separate fired heaters as shown in the schematic diagram

and some installations use a single fired heater with three separate heating coils.

The hot reaction products from the third reactor are partially cooled by flowing

through the heat exchanger where the feed to the first reactor is preheated and then flow

through a water-cooled heat exchanger before flowing through the pressure controller (PC)

into the gas separator.

Most of the hydrogen-rich gas from the gas separator vessel returns to the suction of

the recycle hydrogen gas compressor and the net production of hydrogen-rich gas from the

reforming reactions is exported for use in the other refinery processes that consume hydrogen

(such as hydrodesulfurization units and/or a hydrocracker unit).

The liquid from the gas separator vessel is routed into a fractionating column

commonly called a stabilizer. The overhead offgas product from the stabilizer contains the

byproduct methane, ethane, propane and butane gases produced by the hydrocracking

reactions as explained in the above discussion of the reaction chemistry of a catalytic



reformer, and it may also contain some small amount of hydrogen. That offgas is routed to

the refinery's central gas processing plant for removal and recovery of propane and butane.

The residual gas after such processing becomes part of the refinery's fuel gas system.

The bottoms product from the stabilizer is the high-octane liquid reformate that will

become a component of the refinery's product gasoline.

Catalysts And Mechanisms

Most catalytic reforming catalysts contain platinum or rhenium on a silica or silica-

alumina support base, and some contain both platinum and rhenium. Fresh catalyst is

chlorided (chlorinated) prior to use.

The noble metals (platinum and rhenium) are considered to be catalytic sites for the

dehydrogenation reactions and the chlorinated alumina provides the acid sites needed for

isomerization, cyclization and hydrocracking reactions.

The activity (i.e., effectiveness) of the catalyst in a semi-regenerative catalytic

reformer is reduced over time during operation by carbonaceous coke deposition and chloride

loss. The activity of the catalyst can be periodically regenerated or restored by in situ high

temperature oxidation of the coke followed by chlorination. As stated earlier herein, semi-

regenerative catalytic reformers are regenerated about once per 6 to 24 months.

Normally, the catalyst can be regenerated perhaps 3 or 4 times before it must be

returned to the manufacturer for reclamation of the valuable platinum and/or rhenium content



CHAPTER -4

ATMOSPHERIC AND VACUUM DISTILLATION UNIT

(AVU-I/II)

Introduction

There are two Atmospheric and Vacuum Distillation Units in Barauni Refinery

numbered as AVU-I and AVU-II, each were designed for 1 MMT/year crude processing.

Subsequently another distillation unit without vacuum distillation facility was added. This

unit was designed for 1 MMT/year of crude and known as AU-3. Crude Processing capacity

of both units AVU-I & AVU-II was increased to 1.6 MMT/year by HETO project (Heat

Exchanger Train optimization) in 1990. The above modification (HETO project job was

designed by EIL (Engineer's India Limited) and fabrication/erection job was completed by

M/s. Pethon Engg. Ltd, Mumbai. The units were again revamped in 1998 (M & I) when the

capacity was expanded to 2.1 MMT/year of each of the two units.

Through these units were designed on the basis of evaluation data of Naharkatiya

crude, presently the units have switched on to imported crude due to none availability of

Assam crude.

Process Description

Crude oil (imported) is received from Haldia by pipeline and is pumped from tanks

through Heat Exchangers after exchanging heat with various hot stream, the crude streams

attain a temperature of approx. 393K to 403K. After attaining temperature about 393K to



403K the two crude flows combine together and enter in desalter for separation and removal

of water and salt.

Bi electric desalter is having two energised electrodes. A distributor head splits crude

between the upper and lower pair of electrodes. Crude oil separated from water between the

centre and lower electrodes passes through the upper electrode in a converging countercurrent

flow with the separating water from upper set of electrodes. This creates a second washing

zone for half of the feed in a strong electrical field thereby causing maximum salt removal

efficiency. The two desalter in AVU-I &II are PETRECO BIELECTRIC type which were

commissioned in the year 2001.

Post Desalter

At the outlet of Desalter there are two booster pumps which boost up the crude at

discharge pressure around 15 kg/km.Pre-topping column has 20 Trays (All valve trays with a

bed of packing between 9th

& 10th

tray) and operates on operating conditions.

Pretopped crude stream passes through heat exchangers. After exchanging heat with various

hot products the pretopped crude flows combine and it is segregated again near furnace in

two pass flows before entering the atmospheric heater for further heating and finally fed to



6th tray of main column through two entry nozzles at 340oC.The Furnace is provided with

Air Preheater. Main Fractionating Column has 43 double pass valve trays. Following are the

operating parameters of the main column.

As per design two types of gas oil, one light and other heavy were supposed to be

withdrawn light gas oil from 6th and 18th tray and heavy gas oil from 8th/10th trays at 140-300

oC and 300-350 oC respectively. At present gas oil is withdrawn as 250-370 oC cut from

16th/18th tray. The existing 7th to 14th double pass channel trays were replaced with valve

trays in HETO,1990. Since 1970 heavy gas oil withdrawal was stopped. Main Column

bottom is feed to vacuum column .

Vacuum Distillation

Vacuum distillation is a method of distillation whereby the pressure above the liquid

mixture to be distilled is reduced to less than its vapor pressure (usually less than atmospheric

pressure) causing evaporation of the most volatile liquid(s) (those with the lowest boiling

points). This distillation method works on the principle that boiling occurs when the vapor

pressure of a liquid exceeds the ambient pressure. Vacuum distillation is used with or without

heating the solution. Vacuum distillation increases the relative volatility of the key



components in many applications. The higher the relative volatility, the more separable are

the two components; this connotes fewer stages in a distillation column in order to effect the

same separation between the overhead and bottoms products. Lower pressures increase

relative volatilities in most systems. A second advantage of vacuum distillation is the reduced

temperature requirement at lower pressures. For many systems, the products degrade or

polymerize at elevated temperatures.

Vacuum distillation can improve a separation by:

1. Prevention of product degradation or polymer formation because of reduced pressure

leading to lower tower bottoms temperatures,

2. Reduction of product degradation or polymer formation because of reduced mean

residence time especially in columns using packing rather than trays.

3. Increasing capacity, yield, and purity.

Another advantage of vacuum distillation is the reduced capital cost, at the expense of

slightly more operating cost. Utilizing vacuum distillation can reduce the height and

diameter, and thus the capital cost of a distillation column.

Reduced crude from main column bottom at a temperature of approx. 330 oC is

pumped through Furnace. The Furnace coil outlet (4 passes) combines in one header and

enter into vacuum column at 4th plates through two entry nozzle. Coil outlet temperature is

maintained at about380 oC. Operating condition of Vacuum Column are as follows :



Stabilizer Column

Unstabilised gasoline is pumped to 16th/20/24th

tray of Stabiliser. Feed temperature is

about 110o C. The column has 35 valve trays. Operating conditions of Stabiliser are:-

LPG Caustic Wash

LPG caustic wash facilities were provided in AVU-II and was first commissioned in

Sept,1984 where LPG of AVU–I, AVU-II is washed with caustic solution of 10-12%,

strength.

Heavy Naptha

Heavy Naphtha is drawn from main column ,36th tray, through stripper. Operating

parameters:-



Product Streams Example of AVU-I/II:-

Tempered Water Facilities (Heto - 1990)

During HETO, tempered water facility was provided in AVU-2 . Tempered water is

used as cooling media in S.R. cooler instead of Pressurised cooling water as is being used in

conventional coolers. This facility is common for both AVU-1 & AVU-2. Tempered water is

steam condensate, received from condensate recovery system of refinery, with neutral ph



value after chemical treatment. Use of tempered water in cooler prevents the sealing and

corrosion in cooler tubes thus ensuring the very efficient cooling of product (S.R.) and

minimising to a great extent the maint. of the cooler. Tempered water facility is essentially a

closed circulating system in which the loss of tempered water during circulation is very

negligible.

Corrosion Control

Ammonia is injected in the form of aquous solution for preventing HCL corrosion in

pretopping and main column overheads. Recent modification of this system is the installation

of on line pH meters for measuring pH in both the units.

Ahuralan Injection

Ahuralan is the trade name of an organic inhibitor compound, used for preventing

corrosion of condenser shell. It prevents corrosion by forming a thin protective layer on the

equipment. A 5% W/V and 2% W/V solutions are prepared in AVU-I and AVU-II

respectively. Injection rate in both the units is 5 PPM of overhead contents.

Major Equipment

1. Tubular Furnaces:- Tubular furnace is cylindrical type for pretopping and

vacuum sections. It is box type for the main distillation column. The furnaces have sections

called "Radiation Section" and convection section. A part of the tube in convection zone is

for super-heating steam( used in the process) and the rest is used for heating the oil in tubes.

The inside walls of the furnace are protected against the temperature effects by a refractory

insulation to reduce the outside heat losses. The bottom bed show openings in which burners



are placed. The flue gases go out of the furnace thorough the stack. The stack is protected

inside, in its lower part where the flue gases are still very hot by a wall of refractory bricks. A

damper is located at its base to allow the regulation of the draft. This damper is built with

steel suitable for the flues gases temperature.

2. Burners :- The burner is conceived to burn either gas or oil. Gas burners are of

two types: either with pre-mixing or without premixing. In the first type a part of the

combustion air is mixed with the fuel gas before this has reached the injector nozzle of the

burner. The burners without premixing give a diffusion flame, the combustion air entering the

furnace in a parallel direction with the gas jet and slowly diffusing in it. AVUs gas burners

are of this type. They give a longer and more luminous flame than those with premixing.

AVUs burners are of inside-mix type. In these, the steam and oil are mixed in a chamber

within the burners, and they issue together from the burner as a single stream. Foam formed

in the mixing chamber is directed by the shape and direction of the burner tip so that the

flame is of proper shape and size for the furnace box.The burners with spraying by steam

have a flexibility much higher than those with mechanical spraying



CHAPTER 6

ATMOSPHERIC AND VACUUM DISTILLATION UNIT III

The Process Description

Crude Preheat

Crude is pumped to desalter through two parallel passes in Pre-Desalter Heat

Exchanger Train-1. The first pass consists of four nos. of heat exchangers: The second pass

of heat exchangers also has four nos. of heat exchangers: Both the passes combine in a single

header and enter the desalter.

Desalter Circuit

A static Mix valve and a control valve is provided for mixing water and demulsifier

with crude prior to entry into the desalter. The desalter pressure is controlled at around 9.0

Kg/cm2 (g) The desalted crude is pumped to Pretopping Column .

Heat Exchanger Train II

The discharge is through a series of heat exchangers (6 Nos.). In this network of heat

exchangers, crude is heated by outgoing products to a temperature of around 230 °C.

Pretopping Column

The desalted crude at 230ºC enters the columns for withdrawal of unstabilised

gasoline and heavy naptha.



Heat Exchanger Train III

The bottom product at a temperature of around 250 °C is pumped to furnace through

heat exchangers and then after combining is routed in parallel streams through pre-heat

exchangers (3 Nos). The preheat temperature at the exit is around 270 °C. Part of the bottom

product coming out of the heat exchanger train is sent to Pretopping Column as heat input.

The coil outlet temperature of the furnace is maintained at around 360 °C. Pre topping

column bottom product is sent through the main furnace. The coil outlet temperature is

maintained at around 360°C.

Main Fractionator

The main column is provided with:

1. Valve trays in the top section,

2. KERO / LGO section,

3. Structured packing in LGO / HGO section,

4. The bottom stripping section and

5. Over-flash section.

6. The column bottoms (RCO) is flashed into the Vacuum Column.

Stabiliser Section

Part of the condensed overhead gasoline is pumped through heat exchanger to

stabiliser section.



LPG Caustics Wash

LPG goes to LPG caustic wash-vessel after mixing with caustic.

VACUUM SECTION

The Vacuum column is provided with structured packing in LVGO pumparound

section, LVGO/HVGO fractionation section, HVGO pumparound section, and Wash section

and valve trays in the bottoms stripping section. The column is operated at a top pressure of

70 mm Hg.

K-301 top is provided with a demister to minimize the entertainment of liquid

droplets in the vapour going to overhead-condenser. The side streams of main vacuum

column are as under :

This Reboiler Furnace is a vertical cylindrical heater with convection and radiant

section.

The heater houses 12 nos. of horizontal tubes in convection section and 48 nos. bare

tubes 6" NB of A335 P9 material. These 48 tubes are arranged in double pass arrangement

giving material total radiant heat transfer area of 248.8 m2. The firing of this heater is done

by 4 nos. combination fuel fired forced draft burners provided with pilot burners having



automatic electric ignition system. Refractory material used in the radiant sanction of this

heater is ceramic fiber blanket.

Crude heater is a vertical cylindrical heater with convection and radiant sections.

The radiant section of the heater houses 88 nos. bare tubes of 6" NB of A335 P9

material. These 88 tubes are arranged in four-pass arrangement giving total heat transfer area

of 856.8 M2.

In the horizontal convection section there are 24 nos. bare tubes of A335 P9 material

and 64 nos. of studded tubes with an extended surface area of 950 M2.In the convection

section, there are also 12 nos. of extended surface tubes for steam superheat with an extended

surface area of 70 M2.

The firing of this heater is done by 8 nos. combined fuel fired forced draft burners

provided with pilot burners having automatic electric ignition system. Refraction material

used in the radiant section of this heater is ceramic fiber blanket.

Vacuum heater F-301 is a vertical cylindrical heater with convection and radiant

section.

In each pass of the furnace, there is arrangement for introducing turbulising steam at

convection section inlet and convection section outlet.

The radiant section of the heater houses 54 nos. bare tube of 6" each NB A335 P9

material. These tubes are arranged in two parallel passes giving total heat transfer area of 330

M2.



In the convection section, there are 12 nos. of bare tubes of A335 P9 material of total

surface area of 34.81 M2 & 44 nos. of studded tubes of A335 P9 material of total exposed

surface area of 509 M2.

The firing of this heater is done by 4 nos. of combined fuel fired forced draft burners

provided at the floor with pilot burners having automatic electric ignition system. Refractory

material used in the radiant section is ceramic fiber blanket.

Air Preheater

During normal operation, combustion air for all furnaces is supplied by forced draft

fans. Air is preheated at 230oC in a common air pre-heater.

Air preheating is based on heat exchange between hot flue gas and combustion air.

Hot flue gas leaving the convection section of the furnaces at 323oC is mixed together before

going to shell side of the APH (annular spaces between the finned modules).

The cast iron HT/HTA tubes have integral fins on the inside (air) and outside (flue

gas) surfaces.

Air preheater is provided with glass tubes in the lowest pass in order to avoid

corrosion due to acid condensation in cold flue gases

Documents

trainig Report for iocl