13207314 soft skill time management exercise

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PROJECT REPORT FOR AWARDING OF CERTIFICATE ON

COMPLETION OF SUMMER INPLANT TRAINING

(9th

JULY - 9th

AUGUST 2012)

AT

IOCL Gujarat Refinery (Vadodara)

SUBMITTED BY:

Ashwani Kumar

B.Tech. (Chemical Engineering)

Seth Jaiprakash Mukandlal Institute of Engineering and Technology,

Haryana.


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PREFACE

Though it has been said that best friend a man can ever get is a book but we at this juncture realize that

only books cannot give all the information a person seeks. When any student is unable to understand a

particular topic, he is advised to imagine the whole matter and then try to understand it. Normally, this

method succeeds. But in engineering stream considering the study of wide range of process and

equipments involved in it, it is hard to understand the unit operations and processes just through books

or even with imagination .Unless one happens to see the process, equipments, he is like a soldier who

knows to fire the gun ,but is yet to face a war.

Industrial training is one of the most vital part of a syllabus of chemical engineering, which not only

teaches one the industrial unit operations, equipments and other technical aspects, but also teaches

discipline, interaction with various people irrespective of their posts, the importance of teamwork, etc.

This report contains a brief introduction to GUJRAT REFINERY and knowledge gathered abou

various units in refinery during the training.


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ACKNOWLEDGEMENT

I would like to express my gratitude to all those who gave me the possibility to complete this

training. I want to thank the department of training and management of Gujarat refinery for givingme permission to commence this training. I have furthermore to thank the officers of production who

giving me such knowledge of about the plant and production process. Its really great opportunityfor me by which I had learned here many more of refinery. I am deeply indebted to Gujarat Refinery

who given such opportunity to students by which they complete their vocational training which is

the parts of the course. Without any moral support and help I was not able to visit the plant and learnabout the refinery. I would like to give my special thanks to the person who supported me through

the training at the day of starting to the end of the training.

Our special thanks to

Mr.M.M PARMAR: CPNM (OM&S)

Mr. TAMBOLI SPNE (AU I)

Mr. V. M. RANALKAR( Chief Technical Services Manager)

Mr. SAURABH SETH : PNM (FCC)9

Mr.VENKARAMAN : SPNE(FCC)

Mr. AVALA SRINIVAS : SPNE(HGU III)


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CERTIFICATE

This is to certify that Mr. Deepesh Bhatia , student of University Institute of

Chemical Engineering and Technology, Chandigarh has successfully

completed his industrial training at Indian Oil Corporation Limited(IOCL),

Gujarat Refineryfrom 15 June 2012 to 26 July 2012 under my supervision

and guidance with utmost satisfaction.

It indeed gives us pleasure to highlight that Mr. Deepesh Bhatia has worked

hard and deep sincerity throughout his vocational training. I appreciate his

sincere effort and I am sure that gained during the training will enable him to

take up more challenging tasks in the future.

Date: July 26, 2012 C. P. Ambedkar

Sr. Officer (Tra. & Dev.)


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CONTENTS

Sr. NOTOPIC

1 INTRODUCTION TO IOCL

2 GUJARAT REFINERY

3 UNITS AT GUJARAT REFINERY4 MAIN UNITS

5 UNITS

6 GUJARAT REFINERY (GR II)

7 ATMOSPHERIC UNIT III

8 GUJARAT HYDROCRACKER UNIT(GHC)

9 HYDROGEN UNIT

10 HYDROCRACKER UNIT

11 GUJARAT REFINERY SECONDARY PROCESSINGFACILITIES(GRSPF)

12 FEED PREPARATION UNIT(FPU)

13 FLUID CATALYTIC CRACKING

14 CRUDE DISTILLATION UNIT(CDU)

15 VACUUM DISTILLATION UNIT(VDU)


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16 CATALYTIC REFORMING UNIT(CRU)

17 SULPHUR RECOVERY UNIT(SRU)

18 LEARNING

19 BIBLIOGRAPHY

1.INTRODUCTION:

INDIAN OIL CORPORATION LTD. (IOCL)

Indian Oil, the largest commercial enterprise of India (by sales turnover), is Indias sole representative

in Fortune's prestigious listing of the world's 500 largest corporations, ranked 189 for the year 2004. Itis also the 17th largest petroleum company in the world.

Indian Oil has a sales turnover of Rs. 1, 20,000 crore and profits of Rs. 8,000 crore. Indian Oil has been

adjudged second in petroleum trading among the 15 national oil companies in the Asia-Pacific region.

As the premier National Oil Company, Indian Oils endeavour is to serve the national economy and thepeople of India and fulfil its vision of becoming "an integrated, diversified and transnational energy

major."

Beginning in 1959 as Indian Oil Company Ltd, Indian Oil Corporation Ltd. was formed in 1964 with

the merger of Indian Refineries Ltd. (Est. 1958).

As India's flagship national oil company, Indian Oil accounts for 56% petroleum products market share

42% national refining capacity and 67% downstream pipeline throughput capacity.

IOCL touches every Indians heart by keeping the vital oil supply line operating relentlessly in everynook and corner of India.


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It has the backing of over 33% of the countrys refining capacity as on 1st

April 2002 and 6523 km ofcrude/product pipelines across the length and breadth of the country.

IOCLs vast distribution network of over 20000 sales points ensures that essential petroleum products

reach the customer at the right place and at the right Time.

Indian Oil controls 10 of India's 18 refineries - at Digboi, Guwahati, Barauni, Koyali, Haldia, Mathura,

Panipat, Chennai, Narimanam and Bongaigaon


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2. INTRODUCTION: GUJARAT REFINERY

Gujarat Refinery a prestigious refinery of Indian Oil Corporation Limited began its operation in 1965Since then, the refinery has grown to be the companys largest and countrys second largest refinery.

The refinerys success is built upon business and community partnerships with the people of Vadodara

as well as production of quality products that are compatible with the community and the environment

At the heart of the Gujarat Refinerys success, are its employees and their commitment to Indian Oilsvision and mission.

PROCESSING CRUDE:

Gujarat Refinery is designed to processes indigenous as well as imported crude oil. On an average itprocesses approximately three lakh eight thousand metric tonnes crude per day. Out of the crude slot it

receives, refinery processes around 45% imported crude.

Gujarat refinerys manufacturing and storage facilities consist of 26 major process units, 28 productlines and crude storage tanks with capacity ranging from 300 to 65,000 KLs.

South Gujarat Crude: 2.3MMTPA; supply from ONGC South Gujarat pipeline.North Gujarat: 3.5MMTPA; supply from ONGC North Gujarat pipeline.

Imported low / high Sulphur crude & Bombay high: 6.2 MMTPA Supply from Salaya - Viramgam -

Koyali pipeline.

SALIENT FEATURE OF REFINERY:

First Riser Cracker FCCU in the country. First Hydro cracker in the country. First Diesel Hydro De-sulphurisation Unit. First Spent Caustic Treatment Plant in refineries. First Automated Rail Loading Gantry. First LPG Mounded Bullets in Indian Refineries. Operates Southeast Asias biggest Centralized Effluent Treatment Plant (CETP).

Process Control:

Using the latest electronic technology to monitor and control the plants, engineers run the process units

around the clock, 7 days a week. From control rooms located in each operations area, technical

personnel use a computer-driven process control system with console screens that display colorinteractive graphics of the plants and real-time (current) data on the status of the plants.


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The process control systems allow operators to fine tune the processes and respond immediately toprocess changes. With redundancy designed into the control system, safe operations are assured in the

event of plant upset.

Product Marketing:

A network of product pipelines, tank wagons and tank trucks carries finished products to regionaldistribution center.

In turn, these centers supply products to consumers and industrial customers in Gujarat, Maharashtra,

Madhya Pradesh and Rajasthan.

In addition to this Gujarat Refinery caters to the needs of NCR and Karnataka.

OPERATIONS:

1. Distillation: Modern distillation involves pumping oil through pipes in hot furnaces and separating light

hydrocarbon molecules from heavy ones in downstream distillation towers.

The refining process begins when crude oil is distilled in two large, two-stage crude units. The units are two-stage because they have two distillation columns, one that operates at near

atmospheric pressure, and another that operates at less than atmospheric pressure, i.e., a vacuum.

The lightest materials, liquid petroleum gas like propane and butane, vaporize and rise to the top ofthe first atmospheric column.

Medium weight materials, including jet and diesel fuels, condense in the middle. Heavy materials, called gas oils, condense in the lower portion of the atmospheric column. The heaviest tar-like material, called residuum is referred to as the bottom of the barrel because

it never really rises.

This distillation process is repeated in many other plants as the oil is further refined to makevarious products.

2. Conversion: Refinery converts middle distillates, gas oil and residuum into MS, ATF and HSD, as well as other

fuel oils, by using a series of processing plants. Most of the oil is treated with hydrogen to remove contaminants before the conversion process

Heat and catalysts are then used to convert the heavy oils to lighter products.

Since the marketplace establishes product value, refinerys competitive edge depends on howefficiently it can convert middle distillate, gas oil and residuum into the highest value products.

Cracking is one of the conversion methods, because it literally cracks large, heavy hydrocarbonmolecules into smaller, lighter ones.

Gujarat Refinery uses two cracking methods: fluid catalytic cracking and hydro cracking.


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The Fluid Catalytic Cracker (FCC) uses high temperature and catalyst to crack heavy gas oil mostlyinto gasoline.

Hydro cracking uses catalysts to react gas oil and hydrogen under high pressure and hightemperature to make both ATF and MS.3. Treatment (Removing Impurities):

The products from the crude distillation units and the feeds to conversion units contain some naturalimpurities, such as sulfur and nitrogen.

The sulfur is converted to hydrogen sulfide and sent to the sulfur recovery unit where it is convertedinto elemental sulfur and nitrogen is transformed into ammonia in nitrogen unit and then burnt

through flare.


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3.UNITS AT GUJARAT REFINERY:

1) GR1

Atmospheric Distillation Units, AU1 & AU2: 4.2 MMTPA

AU5: 3.0 MMTPACatalytic Reforming Unit, CRU: 0.33 MMTPA

2) GR2AU3: 2.7MMTPA

UDEX: 0.166 MMTPA

Food Grade Hexane, FGH: 0.03 MMTPA

Methyl Tertiary Butyl Ether, MTBE: 47 MMTPABUTENE 1: 2MMTPA

3) GREAU4: 3.8MMTPA

Vacuum Distillation Unit, VDU: 1.2MMTPA

Bitumen Blowing Unit, BBU: 0.5MMTPAVisbreaker Unit, VBU: 1.6MMTPA

4) GRSPF

Feed Preparation Unit, FPU-1: 2.0MMTPAFluidized Catalytic Cracking Unit, FCC: 1.5MMTPA

5) GHC

FPU-2: 2.97MMTPAHydrogen Generation Unit, HG: 38,000 MTPY

Hydro Cracking Unit, HCU 1.2MMTPA

HYDROGEN-2: 10,000 MTPYDiesel Hydro De-Sulfurization Unit, DHDS: 1.4 MMTPA

Sulphur Recovery Unit, SRU: 88 MMTPD


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6) POWER GENERATION & EFFLUENT TREATMENT

Cogeneration Plant, CGP: 30*3 MWThermal Power Station, TPS: 12*2 + 12.5 MW

Combined Effluent Treatment Plant, CETP: 1500 M3/H

4.MAIN UNITS:

Atmospheric Distillation UnitGujarat Refinery has five primary distillation units AU-1, AU-2, AU-3, AU-4 and AU-5 with a

combined crude processing capacity of 13.7 MMTPA and flexibility of processing indigenous orimported crude.

The various product streams obtained on crude distillation are:

1. Methane, Ethane and Propane mixture as refinery fuel gas.2. Liquefied mixture of propane and butane marketed as3. Liquefied Petroleum Gas (LPG).4. Gasoline fraction.5. Aviation Turbine Fuel (ATF).6. Superior Kerosene (SK).7. High Speed Diesel (HSD).8. Reduced Crude Oil (RCO).

Catalytic Reforming Unit (CRU)Gasoline fractions produced from distillation units containing naphthalene and paraffin type of

hydrocarbons are chemically transformed into aromatic type of hydrocarbons having higher octanenumber.

This unit produces feedstock for UDEX Unit for production of benzene and toluene and feedstock forXylene.


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Diesel Hydro-de-sulphurisation unitThe DHDS process is an environment friendly technology. Gujarat refinery commissioned DHDS unitin June 1999. This unit reduces Sulphur content in HSD to the level of 0.05%.

The unit produces normal and ultra low Sulphur diesel qualities. Ultra low Sulphur diesel is mainlymarketed amongst metro cities.

Hydrocracker UnitTo upgrade the heavy residue to valuable middle distillates Gujarat Refinery has set up a hydro crackerplant with all associated units like Feed Preparation Unit, Hydro cracker unit, hydrogen unit, nitrogen

plant, power plant, Sulphur recovery unit and waste water treatment plant.

The hydro cracker unit is designed to process 1.2 million metric tonnes of vacuum gas oil per annum

produced from feed preparation unit. The unit converts the vacuum gas oil into products like diesel

kerosene, and naphtha, LPG etc. by cracking process in presence of hydrogen. The products generatedare of superior quality.

The unique feature of the hydro cracker unit is its capability to totally convert the feed into diesel and

lighter products i.e. no residue comes out of the unit.

LAB (Linear Alkyl Benzene)LAB is an important and vital raw material, which solely determines the cleaning action of detergent.Our LAB now goes into manufacture of most of the popular detergent brands.

The quality of LAB produced, is the best in the country on various parameters, making it a preferred

grade among the customers.

LAB has also been exported to various countries and has evoked excellent response from overseas

buyers.

MSQU (Motor Spirit Quality Upgradation)Auto fuel policy guidelines stated to supply BS II and EURO III great fuel in Ahmadabad and Suratcities by 1st April 2005 and EURO IV great fuel by 1 st April 2010.

To meet the specifications the MOTOR SPIRIT UPGRADATION unit was set up and commissioned

in October 2006, to produce 850 TMTPA of MS at Gujarat refinery.


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In this unit for the first time Gujarat refinery adopted continuous catalytic reforming regenerationtechnology( CCR regeneration) technology.

Unit has number of processes viz. FCC gasoline splitter, naphtha hydro treater, merox, reformate

splitter and CCRU.


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GUJARAT REFINERY:SEQUENCE OF PROCESSES


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5.UNITS:

5.1 GUJARAT REFINERY (GR-II)

This unit has 4 sub-units under it namely:

Atmospheric Unit-III (AU-III) UDEX FHG MTBE

5.1.1 ATMOSPHERIC UNIT-III

INTRODUCTION OF THE UNIT

Atmospheric Distillation Unit-III was originally designed by Russians to process 1.0 MMTPA of 50:50

mixes of Ankleshwar and North Gujarat Crudes. It was commissioned on 28.09.1967. The Unit has

been revamped to process North Gujarat as well as imported (Low Sulphur) / Bombay High Crudes.

FUNCTION OF PLANT

After the last revamp in May-June, 2000, the plant can process 3.0 MMTPA North Gujarat and

Imported (Low Sulphur) / Bombay High crude in a recommended proportion of 55%NG and 45%

Imported (Low Sulphur) / Bombay High. The unit can also process 100% NG crude. At times of

requirement, the unit can also process slop at a slow rate together with the in-going crude. LPG,

Naphtha, SKO, HSD(SRGO) and RCO/LSHS are normal products obtained from this unit. On demand

from UDEX, Hot Oil is produced here.

PROCESS FLOW DESCRIPTION

DETAILED DESCRIPTION OF THE PROCESS

For convenience of understanding, the unit is divided in various circuits viz. crude supply, feed

preheating, crude pre-topping, furnace, main fractionating column, overhead system, Hy-Naphtha

Kerosene, SRGO, RCO, Stabilizer, Naphtha Stripper, Utilities etc.


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CRUDE STORAGE AND SETTLING

AU-III processes NG crude imported / BH crude and Slop. These are stored in respective tanks

earmarked for them.

Adequate settling time, 12 hours or more after completion of receipt is required for each tank to settle

down water/sludge. The water is thoroughly drained before feeding to the unit. The sludge from tank is

drained to melting pit.

A crude tank prepared as above, is first fed at slow rate by crack opening of outlet valve (bleeding),

along with the already feeding tank. After minimum of 4 hours bleeding, this may be made a complete

feed tank. This procedure is adopted to avoid unit upsets due to possible sudden influx of water or

abrupt feeding of different quality crude from the fresh tank. Feeding from the crude tank to the unit

crude feed pump may be either by gravity, as in the case of low feed requirement, or via crude booster

pump as in the case of higher throughput requirement.

SLOP PREPARATION AND SUPPLY

Slop is injected in the crude line Ex GRE crude. There is an indication given in AU-III CR to control

the slop rate to crude depending on the unit condition. A flow rate indication is also given in the GRE

control room. Slop is taken to unit initially at a slow rate, which can be slowly increased up to 500

TPD, max.

CRUDE BOOSTER PUMP

5 Crude pumps are provided at GRE Crude Control for supplying crude to AU-III. Part of this supply

goes to other GR Units also. Out of these 3 pumps are in NG crude service and 1 pump each in SG &

BH crude service.

FEED PREHEAT CIRCUIT

Crude is supplied to the unit by GRE Crude Controls. Through the crude booster pumps as mentioned

in the above tables provided at GRE Crude Controls, crude enters AU-III. Downstream of the crudebattery limit valve de-emulsifier is injected. On crude line to pump suction start up (circulation) line

hook up is provided. Crude through the crude feed line reaches the crude feed pump H2, H2A, H2B

and H2C. Out of 4 pumps, 3 pumps are running while operating at maximum throughput (9000 +

MT/Day) level. Usually two (2) crude pump suffice is the need. With the help of crude feed pumps,

crude is pumped to a number of heat exchangers to recover heat from run-down products. Crude is

charged to two parallel preheat series branched by 3TV3125A and 3TV3125B. These two series of


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exchangers constitute pre-desalter section of preheat circuit; preheat train-1, which impart a large

quantity of heat to crude. The crude preheat circuit is divided into three sections viz. pre-desalter

(Preheat Train-I), post-desalter (Preheat Train-II) & post-pretopping column (Preheat Train-III).

CRUDE PRETOPPING

The crude after getting preheated enters the pre-topping column K-I (I.D = 2400 mm; Ht = 23750 mm

TL to TL) above tray No. 8 at around 259 C. This column is meant for removal of the lighter ends

from the crude and has 8 sieve trays below flash zone and 21 valve trays above 8th

tray.

The column operates at top pressure of 2.2 - 2.9 kg/cm (g) and a top temperature in the range of 110

C to 129

C. Light naphtha boiling up to about 110

C to 129

C is recovered as overhead product

from this column. This light naphtha also contains the lighter hydrocarbons like off-gas and LPG. The

column top pressure is controlled by 3PC3201 located on E-1 vessel, which actually controls E-1

pressure. The c/v 3PV3201 is set to maintain a pressure fixed in the range of 2.2 2.9 kg/cm (g) by

liberating off- gas either to fuel gas system or to flare system. Safety valve set at 3.15 Kg/cm (g)

pressure is provided on vessel. This PSV releases pressure to flare.

Below the flash zone where 8 trays are provided, crude is steam stripped to vaporize kerosene and

other light components. Stripping steam is introduced below tray no.1 through a flow controller. A

pressure controller is provided at upstream to regulate the stripping pressure. The overhead vapours are

condensed and cooled in the condensers T-7A and T-7B working in parallel and the product is received

in the reflux drum E-1. A reflux temperature indicator is provided on the outlet of T-7A/B. 2 nos of100% capacity safety valve discharging to flare are provided on overhead vapour line to condensers

These PSVs are set at 3.7 kg/cm(g). A provision of steam for flushing and fuel gas back up is provided

on E-1.

MAIN FRACTIONATING COLUMN:

OVERHEAD SYSTEM

Pre-topped crude after getting heated to 355-366C in F-1/F-2/F-3 enters the flash zone of the main

fractionating column K-2 (I.D. = 3400 mm; Ht = 30350 mm, TL to TL) through a 22 nozzle above the

6th

tray. This column has 41 trays, out of which the bottom 1 to 6 trays are sieve trays and 7 to 41 are

valve trays. 5 nos of 100% safety valves set at 1.5 kg/cm(g) are provided at the top of K-2.

These PSVs release excess pressure to atmosphere. One vent line is also provided on the column top

The column K-2 is operated at 0.6 to 1.0 kg/cm(g) pressure. Column K-2 pressure is controlled with


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the help of split range controller. This pressure controller admits gas into E-2 through gas make-up

(from E4 vessel) line or releases gas from E-2 to flare depending on whether the column K-2 pressure

is lower or higher than desired. A safety valve set at 1.2 kg/cm(g) pressure is provided at E-2. ThisPSV releases excess pressure into atmosphere.

Naphtha boiling up to about 110 C to 125 C is the overhead product from column K-2 and is

commonly known as E-2 gasoline. This naphtha is devoid of the light hydrocarbons like gas and LPG

The overhead vapour from the column K-2 enters overhead condensers T-8A, T-8B, T-8C and T-8D

working in parallel and the condensed liquid is received in the reflux accumulator E-2. A reflux

temperature indicator is provided on this line. A stream connection is provided on vessel E-2 for steam

flushing. Ammoniated water and Ahuralan are injected in two O/H vapour lines of K-2 to maintain E-2

boot-water pH and to avoid corrosion in condensers and reflux drum.

One of the pumps H8/H9 takes suction from the bottom of E-2 and partly dischargers through

controller as reflux to column K-2 to maintain the column top temperature between 115 C to 120 C

The balance is discharged through other controller which is cascaded with E-2 level controller

maintaining the H/C level in E-2, and is sent to naphtha rundown as Naphtha-2.

There is a provision for:

Routing off grade E-2 gasoline into intermediate tank-214 of AU-III.

a) Normal routing to general / GOP naphtha.

b) Direct routing of E-2 naphtha to AU-I for reprocessing.

Water accumulation in E-2 is drained through inter-phase level controller 3LC3505 to E-12 or OWS.

DEMULSIFIER

A demulsifying agent is injected into the crude oil at the crude pumps common suction header in the

unit. It is injected at the rate of 13-15 ppm on crude input and of 2-20 ppm on crude while processing

slop depending upon demulsifier quality.

Demulsifier helps in faster demulsification inside the desalter, whereby helping in faster removal of

water injected for dissolving salt.

CAUSTIC INJECTION

Calcium and magnesium chloride present in crude hydrolyze on heating and release HCL that attacks

the overhead system. Some of these calcium and magnesium chloride are removed in the desalters. To

neutralize the chlorides escaping from desalters, caustic solution is added into the crude. In presence of

caustic they get converted into harmless NaCl. The caustic dosing is done at a rate of 30 to 40 ppm on

NG crude and is injected in desalter crude outlets common line via vortex mixer.

Caustic is received from OM&S in the form of caustic dye of approximately 48% strength in tank-C.

Caustic is diluted by adding water to make 6-10% solution. Caustic from tank-C is transformed into


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one of the dilute caustics tanks A and B and a solution of 6.0% strength is prepared by diluting with

service water. Dosing of dilute caustic in crude is done with one of the two pumps H-25 and H-26.

AMMONIA SOLUTION INJECTION

Ammonia is injected into overhead vapour lines of K-1 and K-2 to:

1. Neutralize residual hydrochloric acid by converting it into NH4Cl.

2. Maintain pH of E-1/E-2 water in the range of 6 to 6.5, because effectiveness of corrosion inhibitor is

more in this range of Ph.

Ammonia is received in the unit in 40 kg cylinders. Ammonical water solution is prepared by bubbling

gaseous ammonia from cylinder through fresh water in ammonia tank. There are two ammonia tanks.

GUJARAT HYDRO-CRACKER UNIT (GHC)

HYDROGENUNIT

INTRODUCTION: Gujarat Hydrogen plant with a capacity of 38000 tonnes per annumand producing 99.99% pure hydrogen has come up as a part of Gujarat HydrocrackerProject. Hydrogen is generated in this unit by steam reforming of naphtha employing M/s

LINDES technology. Hydrogen generated in the plant is consumed in Hydrocracker unit

for various chemical reactions. These reactions need very high purity hydrogen tomaintain requisite partial pressure of hydrogen in the Hydrocracker reactor. The fallpurity results in the lowering of the hydrogen partial pressure, which adversely affects the

quality of products from Hydro cracker unit.

FEED: Naphtha

PRODUCT: Hydrogen (99.99% pure)

PROCESS:The process for hydrogen generation involves the following four steps.g) Sulphur Removal

h) Steam Reformingi) High Temperature Shift Conversion.j) Pressure Swing Adsorption (PSA) purification.

Different types of catalysts are used in each of the above four sections. As the process

involves high temperature condition in steam reforming and high temperature shiftconversion, waste heat is utilized for generation of large quantity of steam. The steam

generated in the unit satisfies the requirement in the unit and surplus steam is offered toother units for consumption. The unit is unique in the country due to following:


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k) 10 bed Pressure Swing Adsorption (PSA) system for the purification of

Hydrogen product.

l) Special design of steam reformer involving use of low pressure and low calorificvalue PSA purge gas as the major fuel.m) The microprocessor based process control of the PSA system.

SULPHUR REMOVAL: The nickel-based catalyst used in steam reforming ofhydrocarbons is sensitive to poisoning by sulphur compounds. Typically the sulphurconcentration in the feedstock must be reduced to less than 0.2 ppm before it is

acceptable. This is usually achieved by converting the sulphur compounds, e.g. thiophenemercaptanes, to hydrogen sulfide, which is then removed by an absorbent.

The hydrogenation reaction for conversion to hydrogen sulfide is achieved in a reactor,

bed ofcobalt-molybdenum catalyst or nickel-molybdenum catalyst.R SH + H2 RH + H2S

R is radical; it may be CH3, C2H5Hydrogen sulfide reacts with zinc oxide to produce zinc sulfide and water according to


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following reaction.

ZnO + H2S ZnS + H2O

The rate of reaction is a function of temperature pressure and diffusion processes. Each

molecule of hydrogen sulfide must diffuse to the zinc oxide before reacting to producethe sulfide ion and water. The water must diffuse away from reaction zone, while sulfideion diffuses into the interior of the granule to replace the oxide ion. This process

continues until the whole structure is converted into zinc sulfide.

STEAM REFORMING/SHIFT CONVERSION:The objective of the catalytic steamreforming process is to extract the maximum quantity of hydrogen held in water and thehydrocarbon feedstock. The treatment or purification of reformed gases from steam

reformer depends on the purpose for which the reformed gas is to be used.The common uses are:

n) Synthesis gaso) Hydrogen and carbon monoxide for oxo-alcohols

p) Hydrogen for refineries hydrogenation reactions andq) Reduced gas for direct reduction of iron ore.

The reforming of Natural Gas utilizes two simple reversible reactions:

r) The reforming reaction CH4 + H2O CO + 3H2

s) The water-gas shift reaction. CO + H2O CO2 + H2The reforming reaction is strongly endothermic, so the forward reaction is favored by

high temperature as well as by low pressure while the shift reaction is exothermic and is

favored by low temperature but is largely unaffected by changes in pressure.

To maximize the overall efficiency of the conversion of carbon to carbon-di-oxide and

the production of hydrogen, reformers are operated at high temperature and pressure. This

is followed by the shift process, which by using catalyst permits the shift reaction to bebrought to equilibrium at as low a temperature possible.

In our case, reforming of naphtha/steam mixture takes place in the heated high-alloy

reformer tubes, which are filled with a nickel-based catalyst. The steam reformingreaction along with side reactions is as under:

CnHm +

CO +

CO +

nH2O

3H2

H2O

nCO +

CH4 +

CO2 +

(No Details+ m/2) H2---------(i)

H2O-----------------------------(ii)

H2 ------------------------------(iii)

The reaction equilibrium is controlled by partial pressure of H2, CO, CO2, CH4 and H2O.

Reaction (i) is highly endothermic. Reaction (ii) and (iii) are reversible reaction and are

influenced by hydrogen and steam. Most of the carbon monoxide of the reformed gas isreacted with excess steam to produce addition hydrogen and carbon dioxide. This is


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achieved in high temperature CO shift converter. The catalyst available is in the form of

ferric oxide Fe2O3 (haematite); it is to be reduced to ferrosoferri Fe3O4 (Magnetite) in

presence of hydrogen as reducing agent.


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HYDROCRACKER UNIT

INTRODUCTION:Residue up gradation into middle distillates and light distillates iscurrently being done in the Indian Refineries primarily by employing FCC process,delayed coking process & visbreaking. Visbreaking is adopted primarily to reduce the

viscosity of the residue thereby making it marketable. Delayed coking is adopted if cokeis also to be a product. The quality of products obtained from FCC, delayed Coker &

Visbreaker are relatively poor in quality with respect to stability, & sulphur and have tobe blended with other straight run products to be able to market them. Otherwise, product

treatment would be necessary (Hydro-treatment, Merox treatment etc.). In view of theseproblems Hydro cracking process is gaining more and more popularity for upgrading

residues into higher value products

Hydrocracking is an extremely versatile catalytic process in which feedstock ranging

from Naphtha to Vacuum Residue can be processed in presence of Hydrogen and catalystto produce almost any desired products lighter than the feed. Thus if the feed is Naphtha,

it can be converted into LPG and if feed is Vacuum Gas Oil as in our Refinery, it canproduce LPG, Naphtha, ATF, Diesel in varying proportions as per design requirement.

Primary function of Hydrocracker unit is to maximize middle distillate production inGujarat Refinery.

The Hydrocracker is made-up of three major sections: the make-up hydrogen

compression section, the reactor section (two stage) and the distillation section.

Reactor Section: The feedstock is combined with hydrogen at high temperatures &pressures and is catalytically converted to lighter transportation fuels. The reactor section

is composed of the first stage reactor and the second stage reactor.

Make-up Hydrogen Compression Section: It provides hydrogen to each reactor section;the reaction products are separated and cooled.

Distillation Section: It consists of the atmospheric fractionation, light ends recovery,

LPG treating and a vacuum column.

Hydrocracker Unit operates under two different catalyst conditions viz. Start of Run

(SOR) & End of Run (EOR). When the catalyst is new or freshly regenerated, it is SOR

condition. The catalyst gets deactivated due to coke deposition (about 12-18 months) and

requires regeneration to operate under design stipulations. The operating condition justbefore regeneration is called EOR operation.

FEED: Feed consists of VGO from FPU

PRODUCTS:The primary products from HCU are:t) L.P.Gu) Stabilized Light Naphtha


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v) Heavy Naphthaw) Aviation Turbine Fuel (ATF)/ Superior Kerosene (SK)

x) High Speed Diesel (HSD)


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PROCESS DESCRIPTION:

In Hydrocracker, the VGO feed is subjected to cracking in 2 stage reactors over catalyst

beds in presence of Hydrogen at pressure of 170 kg/cm2 & temperature raging from 365

to 441 deg. C. The cracked products are separated in fractionator. Light ends arerecovered/stabilized in debutanizer column. The process removes almost all sulfur and

nitrogen from feed by converting them into H2S & Ammonia respectively. Thus the

products obtained are free of sulfur & nitrogen compounds & saturated. Therefore, except

for mild caustic wash for LPG, post treatment is not required for other products.

The unit consists of the following sections:

(i) First stage Reactor section.

(ii) Second stage Reactor section(iii) Fractionation Section(iv) Light Ends Recovery section

1) FIRST STAGE REACTOR SECTION:Vacuum Gas oil feed is supplied from FPUand heated in exchangers and brought to the pressure of 185 Kg/sq.cm by feed boosterpumps. It is mixed with recycle hydrogen and pure hydrogen from make-up compressors

and further heated in reactor effluent exchanger followed by furnace up to 385 Deg. Cbefore it enters the First Stage Reactor. The first stage reactor contains three catalyst beds

with two intermediate quench zones which use recycle gas as quenching medium. The

reactor effluent is cooled in exchangers, steam generators and finally in an air fin cooler

up to 65 deg. C. It is flashed in the High Pressure Separator (HPS) from which HydrogenRich gas is recycled back to the reactor. The liquid product from the separator flowsthrough a Power Recovery Turbine (PRT) to the Cold Low Pressure Separator (CLPS).

The first stage reactor converts approximately 40% of the feed to middle distillates andlighter products.

2) SECOND STAGE REACTOR SECTION: Converted feed from the first stagereactor

is removed in the fractionator section and unconverted material from the first stage forms

the feed to the second stage. Feed from vacuum column bottom is boosted up to 185

kg/cm2 and mixed with recycle gas and pure hydrogen from make up compressors and is

heated in the reactor effluent exchanger followed by 2nd stage reactor furnace up to 345

Deg. C before it is sent to the reactor. This reactor also contains three catalyst beds withtwo intermediate quench zones, which use recycle gas as quenching medium. The reactor

effluent is cooled in the exchangers and steam generators up to 204 deg. C and is fed toHot High Pressure Separator (HHPS). Liquid from HHPS flows through a power

recovery turbine, which drives the feed pump, and goes to Hot low pressure separator(HLPS) before going to fractionation section. The hydrogen rich gases are cooled in

exchangers followed by air cooler up to 65 deg. C before entering into Cold High


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Pressure Separator (CHPS).

3) FRACTIONATION SECTION: Liquid from HLPS is heated in the exchangers and


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finally in a furnace up to 345 Deg. C before it is sent to fractionator column. The

overhead products are off-gases and light naphtha. Off gases are washed with Amine to

remove H2S and are sent to the Fuel Gas System. Heavy Naphtha is withdrawn at 146

Deg. C as first draw off. The second draw off is ATF at 188 Deg. C. The third draw off is

HSD at 286 Deg. C. The bottom of the fractionator is pumped to Vacuum Column. Thebottom temperature of the column is maintained at 377 deg. C using a reboiler furnace.

HSD is withdrawn as a side cut of vacuum column and blended with diesel fromfractionator after cooling in exchanger and cooler. The bottom of the vacuum column isfeed for second stage reactor.

4) LIGHT ENDS RECOVERY SECTION: Light Naphtha from the fractionator is sent tode-ethanizer, where gases are removed and sent to Amine Absorber where the H2S is

absorbed in the Amine and H2S free fuel gas is sent to Fuel Gas system. Rich amine with

dissolved H2S is sent to Amine Regeneration Unit in Sulfur Recovery Unit Block. Thebottom of de-ethanizer is sent to de-butanizer, for the recovery of LPG. LPG is taken out

from the top and sent to treating section where it is washed with caustic for removal of

H2S. The stabilized Naphtha from the bottom of the stabilizer is sent to Hydrogen Unit

for production of Hydrogen.

CHEMICAL DOSING:

1) DIMETHYL DISULFIDE (DMDS) INJECTION SYSTEM: Sulfiding is requiredto stabilize fresh or regenerated catalyst, which in turn promotes a smooth start-up, better

activity and lower fouling rate. For sulfiding of catalyst Dimethyl Disulfide (DMDS) is

injected in recycle gas, going to reactor.

2) ANTISTATIC ADDITIVE DOSING SYSTEM:Antistatic additive (Stadis-450)is dosed in ATF, which gives it the property to dissipate the build up static electricity

during its transportation in pipes. The dosing rate is adjusted to meet the specifications ofelectrical conductivity of 50 - 450 Ps/m. The dosing is done in the ATF rundown line

down stream of the cooler.

HYDROCARBON REACTION CHEMISTRY:

Hydrocarbons are classified into four major groups according to the types of carbon-to

carbon bonds they contain:

1) Aromatics- They contain one or more benzene nuclear unsaturated, six member rings

in which some electrons are shared equally by all the carbon atoms in the ring. If some

of the rings share two or more carbon atoms, the compounds are referred to a condensedring, or polycyclic, or polynuclear aromatics. As a group, aromatics have higher carbon-to-carbon ratios than any other group. They have relatively low API gravities and tend to


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produce smoke when burned so they make poor jet fuel. Aromatics have good antiknockproperties and make excellent high-octane gasoline.

2) Naphthenes- They are ring compounds without any benzene nuclei. The rings aretypically five or six membered saturated rings. Naphthenes have intermediate APIgravities and burning qualities.3) Paraffins- They are straight chain or branched-chain. Straight paraffins are called normal paraffinsand have very high freeze points so they make poor jet fuel. Branched-

chain paraffins are called iso-paraffins. They make excellent high smoke, low freeze jet

fuel. As a group, paraffins have the highest API gravities.

4) Olefins- They are reactive molecules, which contain one or more double bonds in anotherwise paraffinic structure. Olefins do not occur naturally in crude oil because any

olefins would have long since reacted to form other molecules during the age longunderground aging process in which crude oil is formed. Olefin can be formed as reaction

intermediates during hydrocracking, but the high hydrogenation activity of the catalystprevents any olefins from showing up in reactor products. Hydrocracker feeds also have

lesser amounts of molecules, which contain chemically bound sulfur or nitrogen atoms inaromatic or naphthanic structures. The following molecules are typical of the kinds

present in hydrocracker feeds and products:

y) Paraffinsz) Naphthenes

aa) Aromaticsbb) Sulfur Compounds

cc) Nitrogen Compounds

CATALYST CHEMISTRY:

Hydrocracking catalysts are dual functional, which means that they have both acid

cracking sites and metal hydrogenation sites. The hydrogenation sites provide olefinintermediates and saturated olefin products. They saturate some of the aromatic rings and

prevent the accumulation of coke on the acid sites by hydrogenating coke precursors. Theacid sites provide the carbonium ion intermediates and the isomerization activity that

result in the dominance of isoparaffin products. More acidic catalysts produce a lighteryield distribution of higher iso-to-normal ratio products. Higher hydrogenation activity

catalysts produce more saturated products with a heavier yield distribution.

CATALYST SULFIDING:

Sulfiding is done to regenerate strong acid sites on catalyst, which were neutralized by

nickel salts during catalyst manufacture. An unsulfided catalyst has much lower cracking

activity and produces products of low iso-to-normal ratio. Sulfiding itself proceeds as twoseparate reactions.

The cracking of DMDS:

CH3-S-S-CH3 + 3H2 2CH4 + 2H2S


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Followed by the sulfiding proper:

2H2S + 3 NiO + H2 Ni3S2 + 3 H2O.


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CATALYST REGENERATION:

Catalyst Regeneration consists primarily of burning off accumulated coke on the catalyst

during the oxidation phase:

4C1H1 + SO2 4CO2 + 2H2O

As an unwanted side reaction, some of sulfur (from sulfiding) is also oxidized:

Ni3S2 + 4O2 NiSO4 + 2NiO + SO2,

to yield nickel sulfate, nickel oxide, and sulfur dioxide. In the reduction phase, the nickelsulfate is eliminated to prevent temperature runaway during subsequent sulfiding:

3NiSO3 + 10H2 Ni3S2 + SO2 + 10 H2O

Since some of the sulfur is retained as nickel sulfide, the subsequent sulfiding uses less

DMDS than used for sulfiding of fresh catalyst. As a side reaction during reduction, metal

oxides are converted to metals:

NiO + H2 Ni + H2O


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GUJARAT REFINERY SECONDARY

PROCESSING FACILITIES (GRSPF)

FEED PREPARATION UNIT (FPU)

INTRODUCTION: Feed Preparation Unit (FPU), a part of Gujarat RefinerySecondary Processing Facilities (GRSPF) was originally designed with a throughput of1.66 MMTPA of RCO. The primary function of this unit was to produce 700,000 T/yearof vacuum gas oil for feed to FCCU along with vacuum diesel and vacuum residue. Lateron, it was decided to revamp the Feed Preparation Unit (FPU) to meet the increased VGO

feed requirement in Fluidized Catalytic Cracking Unit (FCCU), which was alsorevamped, to 1.5 MMTPA.

FEED: mixed RCO (MAX)

PRODUCTS:1. Heavy Diesel2. Vacuum Gas Oil

PROCESS:The process is same as that for vacuum distillation unit of GRE.Four side draw products are obtained from the column:

1) Heavy diesel is obtained as the topside draw product.

2) Light vacuum Gas Oil (LVGO) is obtained as the second side draw product. TheLVGO pump around is used to generate LP steam after which it is returned to the column.

3) Heavy vacuum gas oil (HVGO) is obtained as the third side draw product. A pumparound reflux is also drawn off at this point. The HVGO product exchanges its heat with

RCO after which it is used to generate LP steam.4) Slop Distillate is drawn as the fourth side draw product. The recycle stream is also

drawn off at this point and is mixed with RCO at the entry to the Vacuum furnace. TheSlop Distillate mixes with Vacuum Residue down stream of MP steam generator or

cooled in slop distillate cooler and sent to GRE FO Pool.


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FLUIDIZED CATALYTIC CRACKING (FCC)

INTRODUCTION: During 80's with increased processing of the North Gujarat andBombay High Crudes, the production of LSHS had gone up. This increased productionof LSHS should have been suitably disposed off to enable the refinery to operate at its

maximum throughput for meeting requirements of the petroleum products. This LSHS,which is presently being supplied as fuel for burning, has a good potential of being

refined into high priced distillates, which are in great deficit in our country. The steepincrease in the prices of crude oil and petroleum products in the past few years and

governments policy of conservation of petroleum energy has changed the situation

totally and it became necessary to review the utilization of LSHS more economically andprofitably.

Based on the above consideration, the various alternatives of Secondary Processing

Schemes were examined and it was decided to install Fluid Catalytic Cracking Unit

(FCC) at Gujarat Refinery. In 1982 Gujarat Refinery FCC Unit was commissioned with acapacity of 1 MMTPA.

HISTORY OF FLUIDIZED CATALYTIC CRACKER:Cracking is aphenomenon in which large oil molecules are decomposed into small lower boiling

molecules. At the time certain of these molecules, which are reactive, combine with one

another to give even larger molecules than those present in the original stock. The morestable molecules leave the system as cracked gasoline and reactive ones polymerizeforming fuel oil and even coke. Although primary objective in development of the

cracking process had been to get more and more of gasoline, all other oils having boilingranges intermediate between fuel oil and gasoline is also produced. The originally

developed process of cracking was Thermal Cracking. Use of catalyst for cracking was

first investigated by HOUDRY in 1927. Catalytic cracking has many advantages overThermal cracking viz.

1) Catalytic cracking gives more stable products2) For corresponding yield and quality of gasoline, catalytic cracking unit operates under

less severe conditions

3) Catalytic cracking gives high-octane gasoline (viz.91-94 octane).4) It yields less gas viz. Methane, Ethane and Ethylene.

1) BATCH PROCESS: The first commercial Catalytic Cracking Unit was put into

operation in 1936. It was a Fixed-bed Catalytic Cracking Unit. It consisted of a series ofchamber / reactors, wherein one of them is on-stream, the others will be in the process of

cleaning, regeneration etc. This type of process has a disadvantage of being an

intermittent process having a high initial investment and operating cost.


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2) CONTINUOUS PROCESS: The advantages of continuous process led to the

development of the idea of a moving bed catalyst. Examples of this type are ThermoforCracking; Thermofor Catalytic Cracking and Houndry Airlift processes. In the

Thermofor Catalytic cracking, the palletized catalyst was conveyed between the reactor and regenerator

by means of Bucket Elevators. Higher investment by capacity limitations

of Elevators/Air lift systems together with other engineering and process difficulties ledto the development of latest concept in moving bed catalytic cracking i.e. Fluidized

Catalytic Cracking.

FLUIDIZED CATALYTIC CRACKING: The radical development was made byStandard Oil Co., New Jersey, M.W.Kellogg and UOP in early 1940s in which the

catalyst in the form of fine powder was held in suspension in gas stream. It was foundthat by carefully controlling the catalyst particle size and the velocity of gas movingthrough it, a fluidized bed of catalyst would form which has the properties of liquid. In

the fluidized system, finely powdered catalyst is lifted into the reactor by incoming oil,

which immediately vaporizes upon contact with the hot catalyst and after reaction iscomplete, it is lifted into the regeneration zone. Catalytic crackers using powdered

catalyst in this way are known as FLUIDIZED CATALYTIC CRACKING UNITS.

FEED: VGO and VR from FPU. The feed is characterized by following:

1) CARBON RESIDUE: Carbon residue of the feedstock is determined by CCR and itindicates the coke-forming tendency of feed. Values for good cracking feedstock are

0.2% wt or less.2) METAL CONTENT: Most crude oils contain metallic compounds which can enter the

catalytic cracker either by entrainment or because the compounds are themselves volatileand actually distilled in the feed preparation units. Ni, Fe, Cu are particularly harmful.Cleanliness of a charge stock with respect to metals is judged by its metal factor, which

is defined as: FM = Fe +V +10(Ni+Cu)

where, Fe ,V , Ni and Cu are the concentrations of these metals in ppm in the feedstock.FM below 1.0 represents acceptable feedstock.

3) SULPHUR: It is undesirable in catalytic cracker charge as it is in the feed to anyrefining unit since it causes corrosion of the equipment. Also it increases difficulty of

treating products and lower lead response of catalytic cracker gasoline.

CATALYTIC CRACKING REACTIONS:

C2H4

C6H6

Gas oil feed Iso-octane branched paraffin(30 - 50 C atoms) Cetane

Coke(60 % aromatics)Catalytic cracking reactions produce unsaturated short chains like ethylene, excellent


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high-octane components like benzene and iso-octane and lower molecular weight gas oilslike cetane. During cracking, apart from basic reaction of breaking of big molecules to

small ones, other reactions like isomerization, cyclization, alkylation, polymerization etcalso take place.

CRACKING CATALYST: The catalyst used in catalytic cracking process is a finepowder made up primarily of Alumina and Silica. Basically there are two types of catalyst-amorphous and zeolite. Zeolite catalyst contains molecular sieves and varying quantities of rare

earths. These are formed through reaction of reactive forms of Alumina and Silica.

PRODUCTS: The FCC unit catalytically cracks the vacuum gas oil (VGO) from

vacuum distillation unit (VDU) and feed preparation unit (FPU) to various high pricedhydrocarbons. These hydrocarbon vapors are separated into the following products in the

fractionating and gas concentration section-a) Fuel Gas

b) LPGc) Gasoline of high octane number

d) HSD componentse) LDO components

f) Fuel oil components

PROCESS: FCC consists of three sections:

1) Catalyst section

2) Fractionating section

3) Gas concentration section

Catalytic section consists of the Reactor and the Regenerator. Feed to the Reactor is

obtained by the vacuum distillation of atmospheric residues in FPU. Hot feed from FPU

and balanced cold feed from the storage tank is collected in a Raw Oil charge drum. Theraw oil from the surge drum passes through a series of heat exchangers where it getsheated against hot products i.e. heavy naphtha, LCO, HCO, CLO and slurry. Thetemperature of the feed is raised to around 300- 315 deg C. The combined feed enters the

reactor riser at the bottom. The hot regenerated catalyst at 600 deg C from regeneratorvaporizes the feed, raises it to reaction temperature and supplies the necessary heat of

cracking.

REACTOR: The reactor riser is a vertical pipe in which all the cracking reactions take

place. Hot catalyst enters the cold wall wye section at the bottom of the riser, and meetsthe raw oil and riser steam. The flow of catalyst is controlled to maintain the desired

reaction temperature. The raw oil and the riser steam are premixed in a feed distributor toform an emulsion. The raw oil /riser steam emulsion vaporizes upon contacting the hot

regenerated catalyst, accelerating the catalyst and hydrocarbon vapors up the riser.Cracking reactions are carried essentially to completion in the riser with a minimum of


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over cracking and coke formation. Catalyst and oil contact time using this system isapproximately 3 seconds. Catalyst and hydrocarbon vapors exit the riser into the reactor

through the down turned disengaging arm. The disengaging arm provides the quickmethod of separating the catalyst and hydrocarbon vapors. Catalyst falling from the

disengaging arm combines with the catalyst recovered from the reactor cyclones to enter

the reactor stripping section.

Reactor is a cylindrical vessel with a conical bottom. It provides disengaging space for

the separation of catalyst from the oil vapor. Catalyst after disengaging from oil vapors

falls down and enters the stripper. Oil vapor along with the catalyst particle travels up andenters two single stage cyclones provided at the top of reactor. Entrained catalyst is

separated in Cyclones and returned to reactor bed through cyclone dip legs. Flapper

valves are provided at the end of dip legs to avoid entry of vapors through dip legs.

Vapors from top of both the cyclones leave the reactor separately and join vapor line,which carries vapors to the fractionator.

Catalyst disengaging from the down turned arm disengager and reactor cyclones dip legs

passes into the catalyst stripper, which surrounds the upper portion of the riser, where itflows over stripping grids, counter current to riser steam .The stripping steam displaces

the oil vapor from the catalyst particle and returns the vapor to the reactor for separation

in the cyclones.

REGENERATOR:Coke is deposited on the circulating catalyst in the reaction zone.

Spent catalyst flows from the reactor to the regenerator through the spent catalyst slide

valve (SCSV). The pressure difference across SCSV is around 0.4 kg/cm2. In theregenerator coke is burnt off with controlled combustion air. Air from air blower is sentto a direct fired air heater where it is heated to around 230 deg. C by fuel gas combustion.

This air burns off the coke to CO2 and CO. The heat of combustion raises the catalysttemperature to 640 - 660 deg. C range. This hot catalyst supplies heat to the reactor. Thecatalyst is recirculated to the reactor through a regenerated catalyst slide valve (RCSV).

The pressure drop across RCSV is 0.3 kg/cm2. The regenerator also houses 3 sets of 2

stage cyclones, which separates any entrained catalyst particle from the overhead flue gas.

ORIFICE CHAMBER: The purpose of orifice chamber is to reduce the pressure drop

across the flue gas slide valve. The high-pressure drop across the slide valve would cause

excessive noise and erosion problems. Orifice chamber helps to reduce these problemsand brings down the flue gas pressure from 3.4 to 0.3 kg/cm2, which is just sufficient for

CO boiler. The gases CO and CO2 come out of 3 sets of stage cyclones in regenerator andleaves from the top. The gases pass through the orifice chamber where a series of

restriction orifices reduces the gas pressure. A two-port slide valve (TPSV) installed at

the bottom of the orifice chamber diverts the flue gas either to CO boiler or to stack.

CO BOILER: The CO boiler is just like any other conventional water tube boiler


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consisting of two drums and one superheater disposed at the flue gas path. It is a front

wall fired, medium pressure (MP) & temperature, natural circulation boiler.

The upper drum, which is called steam drum but essentially contains steam and water

both, is fed with hot feed water (130-140C) supplied through a feed control valve. The

colder water form the upper drum flows to lower water drum through a bunch of tubes

called Down Comers which are disposed at the lower temperature zone of the furnace.The water contained in the furnace wall tubes or riser tubes is heated by the heat released

in the furnace on combustion of fuel. The heated water in the riser tubes becomes lighterand moves up into the upper drum. These riser tubes are disposed in such a fashion that it

makes a closed envelope of the furnace covering all the six sides of the furnace so as topick-up maximum possible heat. In this way the water circulates from the upper drum to

the lower drum through the down comers and from the lower drum to the upper drum

through the water wall or riser tubes. This circulation in a boiler is called of natural circulationwhichis based upon the principal of Thermosyphon.


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The furnace where the combustion of fuel takes place is an integral part of the boiler. Theboiler tubes are used to make the enclosure for the furnace followed by insulation and

outer sheeting. The space between the tubes is closed with the help of metallic strips,which are welded to the tubes. Hence entire furnace is of welded construction.

FURTHER PROCESSING OF PRODUCTS: The main products from FCC unitare gasoline and LPG. After these products are separated through fractionation andstabilization section, they are given some chemical treatment like caustic wash and water

wash to remove the impurities still present.Following chemicals are used in FCC/GCU:

1. Caustic Soda

2 Tri-Sodium Phosphate

3 Hydrazine

4 Ahuralan

1) CAUSTIC SODA: Caustic soda is used for LPG and gasoline caustic wash. It removes

H2S and lighter mercaptans from these streams. Caustic with approximately 40-45 %strength is received from LPG station through a 2 line into tank. This caustic is diluted

to (10-15 %) by adding water to tank.

2) TRI SODIUM PHOSPHATE (TSP): Tri-Sodium phosphate is added to MP steam

generators. It helps in reducing scale formation in the steam generators by forming sludge

with the scale forming salts. This sludge goes out of the system during blow downoperations. Solid TSP is received in gunny bags. Required quantity of TSP is added tochemical mixing tanks and solution is prepared by adding DM water and mixing with the

help of motor driven mixer provided on the tank. The normal strength of the solution is

5%.

3) HYDRAZINE (N2H4): While major portion of dissolved oxygen is removed from

boiler feed water in deaerator, residual oxygen in boiler feed water is scavenged with the

help of hydrazine.

N2H4 + O2 2H2O + N223 % solution of hydrazine is received in drums/jerry cans of 50 kg. Hydrazine solution

of 5 % strength is prepared in chemical mixing tank by adding DM water. The tank isprovided with a motor driven mixer.

4) AHURALAN: It is an organic chemical, which acts as a corrosion inhibitor by forming

a continuously renewable monomolecular layer on the metal surface with corrosive

elements, present in the system


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VACUUM DISTILLATION UNIT (VDU)

INTRODUCTION: The Vacuum Distillation Unit (VDU) was designed to process

8,00,000 TPA of RCO (370C + 50:50 North Rumaila & Arab Light). After low cost

1999 revamp VDU can process 1.2 MMTPA of RCO, Heavy Diesel as top product is

used as HSD, LVGO+HVGO used as VGO for FCCU feedstock. Presently there is aprovision for withdrawal of three side cuts.

FEED: The Vacuum Distillation Unit (VDU) was originally designed to process

Reduced Crude Oil (RCO) obtained ex CDU (Crude Distillation Unit) while processingimported crude (50: 50 mixture of North Rumaila and Light Arabian Crude Oils).

However, RCO obtained from various imported crudes and indigenous crudes (BombayHigh, North Gujarat, and South Gujarat Mix.) has been processed successfully.

PRODUCTS: By distilling the RCO under vacuum in a single stage column, it

produces Light vacuum Gas Oil (LVG0), Heavy Vacuum Gas Oil (HVGO) and VacuumResiduum (VR). Slop cut (distillate between HVGO and VR) production facility has been

provided since 1988.LVGO - used as blending component for LDO or HSD or as feed component for FCCU

along with HVGO.HVGO - used as a feed component for FCCU.

VACUUM RESIDUUM (VR) - (Imported) is used as feed for Bitumen Unit.

Excess VR and HVG Oil can be used as feed components to the Visbreaker Unit.Surplus BH VR (while processing Bombay High RCO in VDU) is used as blending

component for LSHS.

PROCESS FLOW DESCRIPTION:

Reduced crude oil, RCO is received in feed surge drum from storage tanks. Hot RCO canbe received from CDU. RCO is pumped by charge pumps to a series of preheat

exchangers and then to furnace from where feed goes to column. At the end of preheating

by preheat exchanger train feed gets heated up to 305C in case of hot feed and up to

292C in case of cold feed.

Preheated RCO is split into two passes and introduced to Vacuum Heater/Furnace

under pass flow control for each pass. MP steam is injected in each pass to encourage

vaporization of feed in the coils. Coil outlet temperature of 395 -398C is maintained.

The partially vaporized RCO is introduced in flash zone of column. LP steam

superheated up to 350C in the heater is used as stripping steam in the stripping section of

the vacuum column. Vaporized RCO along with steam rises through the vacuum column


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and is fractionated into two side withdrawals.

VR along with quench stream is withdrawn from the column bottom by pumps. After


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preheating feed, a quench stream is routed back to the column to maintain bottom

temperature of 355C to avoid coking in the column boot. Further VR goes to LP steam

generator and gets cooled up to 150 0C. VR routing is as follows: (1) Hot VR to BBU, (2)Hot VR to VBU, (3) Hot VR to VR burning facility, (4) Hot VR to IFO drum, (5) Direct

VR injection in BBU after cooling, & (6) After cooling in tempered water cooler VR is

routed to storage at 150C.

The desired vacuum is created in the vacuum column by the vacuum system consisting of

multistage ejectors, precondenser, intermediate condenser, after condenser and hot well.The hot well is located at grade level and correspondingly ejectors are elevated to provide

barometric legs. Small amount of oil carried over with steam from the column isremoved from the seal pot by pump and is routed to slop or to HSD. Sour water from the

seal pot is pumped out by pumps to sour water system.


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CATALYTIC REFORMING UNIT (CRU)

INTRODUCTION: Catalyst Reforming Unit of Gujarat Refinery was designed &commissioned with Russian collaboration in October 1966. The designed capacity of theunit was 3,00,000 MTPA. Unit was revamped for production of Benzene, Toluene &

Xylene in March 1990. The reformer catalyst was changed from monometallic to CK-433(Bimetallic) catalyst of Ms. Ketjen. The new catalyst is very sensitive to the impurities

like Sulfur, Nitrogen, Water, and Heavy Metals etc. Therefore, a new pretreater unit hasbeen set up to remove above. Hydro desulfurization catalyst KF-742 of Ketjen of

Netherlands is used in pretreater. After completion of 9 years life CK-433 was changed toE-603 in Aug-1999.Naphtha of two cut ranges i.e. 70-900C and 110-1400C cut is processed separately inblocked out operation to produce reformate specific for Benzene/ Toluene and Xylene

recovery, respectively.BT Operation: 1,80,000 MTPA of 70-900C cut is processed for 4364 Hrs for producingBT rich reformate which is subsequently processed in the UDEX Plant to produce

Benzene and Toluene.

Xylene Operation: 1,50,000 MTPA of 110-1400C cut is processed for producing xylenerich reformate which can be used to produced xylene.

FEED: Naphtha cut (70-90 deg C) for BT operation (paraffins-32%, naphthenes-45%,

aromatics-22%) and naphtha cut (110-140 deg C) for Xylene operation (parffins-37%,

naphthenes-38%, aromatics-24%)

IMPURITIES: Pretreater Unit is designed for following levels of impurities in naphtha

feed:By Wt.Nitrogen Chloride Heavy metals Sulfur

Water

PRODUCTS:

1.5 ppm 3.5 ppm 30 ppb 200 ppm 150

ppm

PRETREATER: Naphtha obtained from pretreater has following impurity levels (for both

70-900C cut and 110-1400C cut Naphtha operations):

Impurities

Nitrogen Halides Arsenic and heavymetals Sulfur Water

By wt.

0.5 ppm 0.5 ppm 5.0 ppb 1.0 ppm 5.0 ppm

REFORMER: Stabilized reformate, Hydrogen rich gas, Stabilizer off gas

Stabilizer

vapor distillate

CHEMICAL ADDITION:


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1) SULFIDING AGENT: Dimethyl disulfide (DMDS) added to both pretreater andreformer catalyst

2) CHLORIDING AGENT: Carbon Tetrachloride


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3) CORROSION INHIBITOR: CONTROL 57 or equivalent

4) ALKALINE MEDIUM: Sodium Carbonate. At the time of catalyst regeneration,

alkaline water is circulated downstream of feed effluent exchangers to avoid acid attackin product coolers, product separators and associated piping.

CATALYST SPECIFICATION:

PRETREATER: CATALYST- KF-742-1,3 Q having MoO3, CoO, Na2O, Fe, SO4,

balance is Al2O3. Surface area is around 260 m2/gREFORMER: Bimetallic CATALYST E-603(ENGEL HARD) having Platinum,

Rhenium, heavy metals, Iron, Na, K, Cl and support is alumina .

1) Platinum metal acts as dehydrogenating agent.2) Rhenium decreases the rate of coke formation by hydrogenation of coke precursors on

the catalyst surface. Rhenium also helps in preventing the Platinum crystal growth bybreaking the intermolecular forces of two adjoining platinum crystals. Platinum is the

active metal in the reforming reactions whereas Rhenium is a deactivation inhibitor.3) The chloride content of catalyst helps in promoting the isomerization andhydrocracking reactions and serves as an acid function of the catalyst.

Advantages of bimetallic catalysts are:1) Gives maximum aromatic yield.

2) Cycle length and life is more.3) Low pressure operation & minimum recycle gas flow

4) Have good mechanical strength.5) Less platinum content and hence less investment.

Catalyst Poison- anything which reduces the activity of the catalyst is a poison e.g. coke,sulfur, water, nitrogen, arsenic, lead, copper etc.

PRETREATMENT:

INTRODUCTION: Structurally hydrotreating catalyst may be defined as a porous Al2O3

support, which carries molybdenum oxide as a bound monolayer. Cobalt or Nickel

promoter ions are deposited on to the surface of molybdenum alumina structure.

To obtain maximum activity of hydrotreating, metal oxides have to be converted into

sulphides and to be maintained in sulphide phase during presulfiding procedure either

with the feed itself or with the external sulfiding agent. At high temperatures, the metaloxides are partially reduced by hydrogen, which result in loss of activity. Reduction of the

metal oxides to metals or lower valence oxides becomes significant at catalysttemperature above 3000C. Once reduction has occurred, it is practically impossible to

convert the metals to their sulphides. If not enough sulphur has been added to the catalyst,before the catalyst temperature is set at operating level, the same irreversible reduction

may occur. Because of possible reduction, the fresh or the regenerated catalyst should notbe contacted with hydrogen at temperature above 2000C, without other reactive sulphur


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compounds.

HYDROTREATING REACTIONS: Predominantly, there are two types of reactions,which occur during pretreatment:


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1) Hydro Desulfurization: The sulfided catalyst reacts with organic sulphur to give

inorganic sulphur (H2S) and hydrocarbon at high temperature and pressure.

S + 4H2 H2S + C4H10

C2H5SH + H2 C2H6 + H2S

The reaction rate for each compound decreases with its molecular weight. In general, the

sulphur present in aromatic type structure is more difficult to remove than in straight

chain molecules.2) Hydro Denitrogenation: Hydro denitrogenation occurs simultaneously with hydro

desulfurization. Nitrogen containing compounds are converted to saturated hydrocarbonsand ammonia.

3) Hydrogenation of Aromatics and olefins: Although it is not desired in most cases somehydro-generation of aromatics and olefins will occur in hydro-treating process.

REFORMING:

INTRODUCTION: Reforming process is carried out at relatively high temperature and

pressure by passing the Naphtha feed stock over a bed of catalyst. Typical operating

conditions of Reformer are: Reactor inlet T= 5010C - 5160C; Pressure=16.90 kg/cm2g. Inthe reforming process, structures of hydrocarbon molecules are rearranged to form more

of higher-octane aromatics. Predominantly, there are five different types of reactions,which occur during reforming.

1) Aromatization of Naphthenes & Paraffins:Dehydrogenation of Naphthenes-

Cyclohexane Benzene + 3H2

The dehydrogenation reactions are highly endothermic and cause a decrease in

temperature as the reaction proceeds. They have the highest reaction rates and they occurmostly in the first two reactors.

Dehydrocyclization of Paraffins-

C6H14 Cyclohexane + H2 Benzene + 3H2

n-HexaneThis reaction is also endothermic and has low reaction rate2) Isomerization of Naphthenes & Paraffins:

Isomerization of Naphthenes-Methyl Cyclo pentane Cyclo hexane

Isomerization of Paraffins-

H-H-H-H-H-H-H H-H-H-H-H-H


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H-C-C-C-C-C-C-C-H H-C-C-C-C-C-C-H

H-H-H-H-H-H-H H-H-H-H-CH3 -H


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n-Heptane Iso-heptane

3) Hydrocracking:

C8H18 + H2 C3H8 + C5H10

n-Octane Propane Pentene

These reactions are highly exothermic. They are relatively slow reactions and there fore

most of the hydrocracking of straight chain paraffins result in octane improvement buthydrocracking of Naphthenes will reduce the Naphthenes potential used for conversion in

Aromatics.4) Hydrogenation of Olefins: Olefins formed during cracking or present in feed are

instantaneously saturated with Hydrogen.

C5H10 + H2 C5H12

Pentene n-pentane

5) Desulfurization:

Thiophine + 5H2 H2S + C4H10

Butane

In reforming, endothermic reactions dominate and the net result is considerable drop in

temperature of the reaction mixture, as it passes through the catalyst bed. An increase in

temperature increases the rate of all reactions. The reduction in temperature will reducethe reaction rates such that the conversion would cease, if no additional heat will be

supplied to the reactants. Some of the reforming reactions are slow reactions, whichrequire more residence time. Therefore the catalyst is placed in a number of reactors. The

reaction mixture picks up heat from the furnace before entering each reactor formaximum conversion.

In a reversible reaction, for a given value of temperature and pressure, not more than a

certain conversion can be reached, even if, the reactants are kept under the reaction

conditions for infinite time. To shift the reaction in forward direction either temperature

is to be increased or H2 partial pressure is to be decreased to have maximum conversion.As decrease in pressure may lead to coke formation on the catalyst, hence instead of

reducing the system pressure, reactor inlet temp is increased.


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SULPHUR RECOVERY UNIT (SRU)

AMINE REGENERATION UNIT (ARU)

INTRODUCTION: Rich amine saturated with hydrogen sulfide received from DHDS,

is treated in ARU, which consists of a conventional stripping column equipped withassociated reboiler and overhead condenser facilities. Hydrogen sulfide and other light

components are removed as overhead products and lean amine as bottom product fromthe amine stripper. The overhead gases are sent to SRU while the bottom product lean

amine is sent back to DHDS. The unit consists of 4 sections:i) Rich amine section

ii) Amine regeneration section

iii)Lean amine sectioniv)Amine storage section

FEED: Feed to ARU is rich amine (H2S 76 Kmol/hr).

PRODUCT: Product leaving ARU is lean amine (H2S 4 Kmol/hr) from the bottom of

the amine stripper and H2S rich gas from the overhead.

PROCESS:

1) RICH AMINE SECTION: The rich amine section collects rich amine from the amine

absorbers. Rich amine from the recycle gas scrubber and stripper gas amine absorber iscombined and send directly to the rich amine flash drum (RAFD). The RAFD separates

any entrained liquid or gaseous hydrocarbons from the rich amine. Hydrocarbon vapor

separated in the RAFD, which also contain some hydrogen sulfide and water vapor, isscrubbed with a small lean amine slipstream in nth stack portion of the RAFD. The

stacked portion of RAFD consists of randomly packed carbon Raschig rings to provideintimate contact between off gases and lean amine. The sweetened off gas flows through

a backpressure control valve to acid gas relief header.

2) AMINE REGENERATION SECTION: Rich amine from the bottom of the RAFDis pumped by rich amine pumps and flow through the tube side of the rich-lean amine

exchanger. In this exchanger the rich amine is heated by the lean amine from the bottomof the amine stripper, which is cooled thereby recovering the heat of the lean amine. The

heated rich amine flows through a level control valve into the amine stripper. The amine

stripper strips nearly all of the hydrogen sulfide from the rich amine, thus regenerating itto lean amine.


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Stripping gas is generated in the amine stripper reboiler by vaporizing a portion of the

lean amine in the column bottom. A small amount of live stripping steam is also injected

in the reboiler return line to stripper to maintain water balance in the entire amine system.


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The stripping gas flows up through the column thereby stripping hydrogen sulfide from

the rich amine flowing counter current. The amine stripper reboiler uses desuperheatedMP steam as the heating medium. Reboiler heating rate is controlled by controlling the

order to prevent amine degradation.

Off gas from the top of the amine stripper, containing hydrogen sulfide, some light

hydrocarbons and water vapors flows to the air-cooled amine stripper trim cooler. As thevapor is cooled some water vapor is condensed. The two-phase stream then flows to the

amine stripper receiver. The liquid from the receiver is pumped by the amine stripperreflux pump as reflux back to the top tray of amine stripper. The acid gas from the top of

the receiver flows to SRU.

3) LEAN AMINE SECTION: A slipstream of lean amine flows to the filtration system,

which filters lean amine through a series of 3 filters. The filtration system contains aseries of 3 filters: upstream mechanical filter, carbon filter and downstream mechanicalfilter. The lean amine from the amine regeneration unit is discharged to diesel union

fining unit.

4) AMINE STORAGE SECTION: High (99wt % DEA) solid amine is supplied to the

amine regeneration unit in drums. The solid amine is melted in the amine melt tank usingsteam, to form amine solution. Amine is diluted to 25-wt % DEA solution used in the

refinery at the amine storage tank. The 25% amine solution is periodically pumped by

amine transfer pump to regeneration section to replenish the amine loss.

SULPHUR RECOVERY SECTION

FEED: The feedstock of SRU is a mixture of acid gas from ARU (H2S 2817 kg/hr) and

acid gas from Sour Water Stripper (H2S 358 Kg/hr).

PRODUCT: Liquid sulphur (99 wt% purity on dry basis)

PROCESS:

The amine acid gas feed from the ARU is introduced via a knock out drum. The SWS gasfeed from the sour water stripper unit is introduced via another knock out drum. Sour

water separates in the knock out drum, is intermittently collected in the sour water drainvessel and routed back to the sour water stripper unit by nitrogen propulsion. The acid gas

feed is split evenly over the two Claus trains.

The air to main burner is supplied by main air blower, which also supplies air to the

Superclaus stage and the sulphur degassing. To remove the heat generated in the main


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burner the gas passes through the tube bundle located in waste heat boiler. The gas is

cooled there by generating HP steam. Then the process gas is introduced in the first


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sulphur condenser in which it is cooled, the sulphur vapor is condensed and the liquid

sulphur is separated from the gas.

Upstream of the first reactor, the process stream from the waste heat boiler is heated by

the first steam reheater to obtain the optimum temperature for catalytic conversion. The

H2S and SO 2 react over a titanium oxide type catalyst until equilibrium is reached. The

effluent gas from the first reactor passes on to the second sulphur condenser. The process

gas passes to the second steam reheater after which it is once again subjected toconversion in the second reactor and cooling in the third sulphur condenser. The inlet

temperature of the second reactor is 210 deg. C. Then the process gas passes to the thirdsteam reheater and the third reactor. The sulphur is condensed in the fourth sulphur

condenser .The inlet temperature of the third reactor is 195 deg. C.

To obtain a high sulphur recovery the process gas from the combined Claus trains is

passed to the fourth and the last catalytic stage i.e. SUPERCLAUS stage. The processgas is heated in the fourth steam reheater after which preheated air is injected in the

process gas. Hydrogen sulfide is selectively oxidized into sulphur. The SUPERCLAUS

reactor contains the special selective oxidation catalyst .The gas then passes to the fifthand the last condenser. The inlet temperature of the SUPERCLAUS reactor is 220 deg. C.

In the condenser the sulphur vapor is condensed. The sulphur is cooled in sulphur coolerand subsequently drained into sulphur pit, which is equipped with degassing facilities.

The heat liberated in the waste heat boiler and condenser is utilized to generate steam.

SULPHUR DEGASSING PROCESS: The sulphur as it is produced in the train containsabout 350 ppm (wt) hydrogen sulfide. To reduce the hydrogen sulfide content, sulphur

stripping has been incorporated. Two bubble columns are located in sulphur pit. A

bubble column is a box open at the top and bottom. Each bubble column is divided into

two sections by a separation baffle. This baffle prevents channeling of undegassedsulphur. Degassed sulphur flows through a rectangular hole in the separation baffles. The

stripping air is supplied by main air blower. In the column sulphur is vigorously agitatedby bubbling of air through liquid sulphur there by accelerating decomposition of

polysulfides into hydrogen sulfide and sulphur, stripping hydrogen sulfide from sulphurand oxidizing hydrogen sulfide partly to sulphur. The released gas, together with the air,

is drawn by steam ejector to the thermal incinerator.

THERMAL INCINERATOR: In thermal incinerator, the combustible components in the

vent gas from sulphur pit are thermally oxidized at a temperature ofexcess of air. The gas to be incinerated is heated to the required temperature by mixing itin the thermal incinerator, with hot flue gases from the incinerator burner. The flue gas

from the incinerator is sent out through chimney at much higher altitude to take for theenvironment pollution. Thus it is a suitable way for the disposal of undesired polluting

gases and side-by-side a large amount of steam is also produced by recovering the heat


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content of gases that are burnt in the incinerator.


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REACTORS:

Function of Claus reactors:i) Claus reaction at catalytic region


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2 H2S + SO2

3/x SX + 2 H2O + 93 KJ

(X = 6 and 8 mainly)

ii)Hydrolysis of COS and CSZ at temperatures above 300C

COS + H2O

CS2 + 2 H2SRequirements:

CO2 + H2S

CO2 + 2 H2S

i) Active catalyst for Claus reaction

ii) Catalyst able to withstand sulfation due to free O2

iii)Catalyst withstanding residual NH3iv)Low pressure drop

v) Catalyst withstanding emergency conditions, such as temperature runaway.

Claus Process Limitations:

i) Thermodynamically limited conversion: 2 H2S + SO2 3 S + H2O

ii) Increases H2O content to 30 vol% decreasing H2S and SO2 concentrationsiii)Formation of non-recoverable S-compounds due to side reactions

Function of Superclaus reactor:

SUPERCLAUS reaction at catalytic region

H2S + 0.5 O2Requirements:

-----> 1/8 S8 + H20 + 208 kJ

i) Active catalyst for SUPERCLAUS reactionii) Catalyst withstanding sulfidation on lack of oxygen

iii)Low pressure drop

iv)Catalyst withstanding emergency conditions, such as temperature run away


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INDUSTRIALLY DEFINED PROBLEM

Problem Statement: - High chloride content monitored in the Surge Drum.

Problem Description: - In AU-3 (Atmospheric Unit III) of GR-II, it has been found that thecontent of chlorides in boot water of surge vessel E2 is very high i.e. 110ppm, but the designed

acceptable limit is less than 10ppm, whereas the pH of boot water is in acceptable limits of 6.50.2.

Process Description:-

Initially the Crude from the storage tank is sent to the Preheat Train 1, where it is heated upto 1400

C

Then it is diverted to two simultaneously (parallel) run desalters (old and new). From the desalters, the

crude is sent to preheat train 2 where the temperature is raised to 2300 C. This preheated crude is sent to

a Flash Column (K-1). The bottom product products are sent to Furnace where the temperature is raised

to 3600

C and then to main Fractionating column (K-2) for further treatment. The overhead product

from K-2 after cooling is sent to the surge vessel (E-2), where excess of chloride is detected.

BRIEF PROCESS FLOW AND EQUIPMENT DESCRIPTION

CRUDE SUPPLY:-

These are the specifications of the Crude used in AU-III

S

r.

N

o.

Specifications UNIT N/G B/HIMP

(Kuwait)

1 Density @ 15C. gm/cc 0.8927 0.8278 0.8723

2 Viscosity @ 20C

30 C37.8C

40C

50C

CSt -

-

68.0

42.5

-

3.75

3.28

2.24

19.5

13.8-

-

-

3 Pour Point C + 24 + 30 +36

4 Sulphur % wt. 0.16 0.17 2.49

5 CCR (Conradson) % Wt. 5.43 1.20 6.20


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6 Acidicity (i) Total MgKOH/g

m

3.88 0.15 0.13

(ii)Inorganic ,, 0.002 -

7 KUOP - 11.95 11.70 -

CRUDE STORAGE AND SETTLING

AU-III processes NG crude imported crude/ BH crude of 28o API a

13207314 soft skill time management exercise

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