VOCATIONAL TRAINING REPORT

INDIAN OIL CORPORATION LTD.

GUJARAT REFINERY

Submitted by:

Shashank JhaBachelor of Chemical Engineering, 2nd yearDepartment Of Chemical EngineeringJadavpur UniversityKolkata-32

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ACKNOWLEDGEMENTS

I would like to thank Mr. Sukumar Ray, DGM (PN), Gujarat Refinery, IOCL, for giving me the opportunity to interact with experts of the industry at Gujarat Refinery. I sincerely express my gratitude to Mr.Ashwin Kumar for guiding me in my study of the subject and for his valuable suggestions. We would also like to thank the other staff members at the company for creating an environment conducive for undertaking this kind of a study. Finally we would like to express my sincere gratitude to my parents, for helping me to undertake this training and constantly encouraging me to interact with the experts and make the best use of the immense opportunities available at the refinery.

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Table Of Contents

Content Page NumberCover Page 1Acknowledgement 2Table Of Contents 3Introduction 4-5Gujarat Refinery, Overview 7-8Units at GR, IOCL 9Product-uses 10Block Flow Diagram, GR, IOC 11GRSPF 12FPU 12FCC 13-17PFD-FCC 18Product-Processing 19GHC 20H2 Unit 20-21Hydro-Cracker 22-26VDU 27-28LAB 33-37

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1. INTRODUCTIO N

Indian Oil, the largest commercial enterprise of India (by sales turnover), is India’s sole representative in Fortune's prestigious listing of the world's 500 largest corporations, ranked 189 for the year 2004. It is also the 17th largest petroleum company in the world. Indian Oil has a sales turnover of ` 1, 20,000 crore and profits of ` 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 Oil’s endeavor is to serve the national economy and the people of India and fulfill 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 Indian’s heart by keeping the vital oil supply line operating relentlessly in every nook and corner of India. It has the backing of over 33% of the country’s refining capacity as on 1st

April 2002 and 6523 km of crude/product pipelines across the length and breadth of the country. IOCL’s 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 - with a current combined rated capacity of 49.30 million metric tones per annum (MMTPA) or 990 thousand barrels per day (bpd).

Indian Oil’s world-class R&D Center has won recognition for its pioneering work in lubricants formulation, refinery processes, pipeline transportation and bio-fuels. It has developed over 2,100 formulations of SERVO brand lubricants and greases for virtually all conceivable applications - automotive, railroad, industrial and marine - meeting stringent international standards and bearing the stamp of approval of all major original equipment manufacturers. The center has to its credit over 90 national and international patents. The wide range of brand lubricants, greases, coolants and brake fluids meet stringent international standards and bear the stamp of approval of all major original equipment manufacturers.

Indian Oil operates 17 training centers throughout India for up-skilling, re-skilling and multi-skilling of employees in pursuit of corporate excellence. Among these, the foremost learning centers -- the Indian Oil Institute of Petroleum Management at Gurgaon, the Indian Oil Management Center for Learning at Mumbai, and the Indian Oil Management Academy at Haldia -- have emerged as world-class training and management academies. Indian Oil Institute of Petroleum Management, the

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Corporation's apex center of learning, conducts advanced management development programmes in collaboration with reputed institutes. It also offers a unique mid-career International MBA programme in Petroleum Management.

Indian Oil aims at maintaining its leadership in the Indian hydrocarbon sector by continuous assimilation of emerging Information Technology and web-enabled solutions for integrating and optimizing the Corporation's hydrocarbon value chain. It is currently implementing an IT re-engineering project titled Manthan, which includes an Enterprise Resource planning (ERP) package which will standardize and integrate the Corporation's business on a common IT platform through a robust hybrid wide area network with appropriate hardware.

RefineriesDigboi Refinery, in Upper Assam, is India's oldest refinery and was commissioned in 1901. Originally a part of Assam Oil Company, it became part of IndianOil in 1981. Its original refining capacity had been 0.5 MMTPA since 1901. Modernisation project of this refinery has been completed and the refinery now has an increased capacity of 0.65 MMTPA.

Guwahati Refinery, the first public sector refinery of the country, was built with Romanian collaboration and was inaugurated by Late Pt. Jawaharlal Nehru, the first Prime Minister of India, on 1 January 1962.

Barauni Refinery, in Bihar, was built in collaboration with Russia and Romania. It was commissioned in 1964 with a capacity of 1 MMTPA. Its capacity today is 6 MMTPA.

Gujarat Refinery, at Koyali in Gujarat in Western India, is IndianOil’s largest refinery. The refinery was commissioned in 1965. It also houses the first hydrocracking unit of the country. Its present capacity is 13.70 MMTPA.

Haldia Refinery is the only coastal refinery of the Corporation, situated 136 km downstream of Kolkata in the Purba Medinipur (East Midnapore) district. It was commissioned in 1975 with a capacity of 2.5 MMTPA, which has since been increased to 5.8 MMTPA

Mathura Refinery was commissioned in 1982 as the sixth refinery in the fold of IndianOil and with an original capacity of 6.0 MMTPA. Located strategically between the historic cities of Delhi and Agra, the capacity of Mathura refinery was increased to 7.5 MMTPA.

Panipat Refinery is the seventh refinery of IndianOil. The original refinery with 6 MMTPA capacity was built and commissioned in 1998. Panipat Refinery has doubled its refining capacity from 6 MMT/yr to 12 MMTPA with the commissioning of its Expansion Project.

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Bongaigaon Refinery is the eight refinery of Indian Oil. It became the eighth refinery of Indian Oil Corporation Limited after merger of Bongaigaon Refinery & Petrochemicals Limited with IOCL w.e.f. 25th March 2009. It is located at Dhaligaon in Chirang district of Assam, 200 Kms west of Guwahati.The present crude processing capacity of the refinery is 2.35 MMTPA. The refinery has two Crude Distillation Units of 1.35 MMTPA and 1.00 MMTPA capacities, two Delayed Coker Units each of 0.5 MMTPA capacity, one Coke Calcination Unit of 0.075 MMTPA and Catalytic Reformer of 160,000 MTPA naphtha feed capacity and an LPG Bottling Plant.

It is believed that the future IOCL refinery Will be Paradeep Refinery. It is expected to be handover at 2012.

Subsidiary refineries — Chennai Petroleum (9.5 MMTPA)

Indian Oil controls 10 of India's 18 refineries with a current combined rated capacity of49.30 million metric tonnes per annum (MMTPA). All refinery units are accredited withISO 9002 and ISO 14001 certifications.

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GUJARAT REFINERY: AN OVERVIEW

The Gujarat Refinery at Koyali in Gujarat in Western India is Indian Oil’s largest refinery. The refinery was commissioned in 1965. Its facilities include five atmospheric crude distillation units. The major units include CRU, FCCU and the first Hydro- cracking unit of the country. Through a product pipeline to Ahmedabad and a recently commissioned product pipeline connecting to BKPL product pipeline and also by rail wagons/trucks, the refinery primarily serves the demand for petroleum products in western and northern India.

When commissioned, the Gujarat refinery had a design capacity of 3.0 MMTPA. The capacity has since been increased to its present capacity of 13.70 MMTPA by low cost debottlenecking. The company has already commissioned the facilities for MTBE and Butene-1 production. The refinery also produces a wide range of specialty products like Benzene, Toluene, Food Grade Hexane, solvents, LABFS, etc. The Gujarat Refinery achieved the distinction of becoming the first refinery in the country to have completed the DHDS (Diesel Hydro De-sulphurisation) project in June 1999, when the refinery started production of HSD with low sulphur content of 0.25% wt (max.).

A project for production of high value LAB (Linear Alkyl Benzene -- which is one of the major raw materials used in manufacturing detergents) from kerosene streams has been completed recently and started on 15th August, 2004. In order to meet future fuel quality requirements, MS quality improvement facilities are planned to be installed by2006.

Some of the salient features of Gujarat Refinery are:1) First Riser Cracker FCCU in the country2) First Hydro Cracker in the country3) First Diesel Hydro Desulfurisation Unit in the country4) First spent caustic treatment plant in refineries5) First automated rail loading gantry6) First LPG mounded bullets in Indian refineries7) State-of-the-art CETP8) Quality Management System (ISO- 9001:2000)9) Environmental Management System (ISO – 14001)10) International Safety Rating System (ISRS) LEVEL 9(Highest) First

organization in country; one amongst 30 refineries in world

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UNITS AT GUJARAT REFINERY

1) GR1§Atmospheric Distillation Units, AU1 & AU2 : 4.2 MMTPA§AU5 : 3.0 MMTPA§Catalytic Reforming Unit, CRU : 0.33 MMTPA

2) GR2§ AU3 : 2.7 MMTPA§ UDEX : 0.166 MMTPA§ Food Grade Hexane, FGH : 0.03 MMTPA§ Methyl Tertiary Butyl Ether, MTBE : 47 MMTPA§ BUTENE 1 : 2 MMTPA§ Pilot Distillation Fraction, PDF

3) GRE§ AU4 : 3.8 MMTPA§ Vacuum Distillation Unit, VDU : 1.2 MMTPA§ Bitumen Blowing Unit, BBU : 0.5 MMTPA§ Visbreaker Unit, VBU : 1.6 MMTPA

4) GRSPF§ Feed Preparation Unit, FPU-1 : 2.0 MMTPA§ Fluidized Catalytic Cracking Unit, FCCU : 1.5 MMTPA

5) GHC§ FPU-2 : 2.97 MMTPA§ Hydrogen Generation Unit, HGU-1 : 38,000 MTPY§ Hydro Cracking Unit, HCU : 1.2 MMTPA§ HYDROGEN-2 : 10,000 MTPY§ Diesel Hydro De-Sulfurization Unit, DHDS : 1.4 MMTPA§ Sulphur Recovery Unit, SRU : 88 MMTPD§ Nitrogen Unit

6) POWER GENERATION & EFFLUENT TREATMENT§ Cogeneration Plant, CGP : 30*3 MW§ Thermal Power Station, TPS : 12*2 + 12.5 MW§ Combined Effluent Treatment Plant, CETP : 1500 M3/H

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PRODUCT END USESLPG Cooking Gas (marketed as ‘INDANE’)Benzene Raw material for petrochemicalsToluene Raw material for petrochemicalsNaphtha Raw material for petrochemicalsMotor Spirit (90 Octane) ‘Petrol’ for vehiclesAviation Turbine Fuel (ATF) Fuel for jet aircraftSuperior Kerosene (SK) Illuminant, domestic purposeHigh Speed Diesel (HSD) Diesel locos, trucks, buses, shipsLight Diesel Oil (LDO) Small engines attached to irrigation pumpsLow Sulphur Heavy Stoke (LSHS) Fuel in thermal power stationsFuel Oil (FO) Industrial Furnaces/BoilersBitumen Road surfacingn-Heptane As solventARO Used in aluminium rolling industriesLinear Alkyl Benzene (LAB) Detergent ManufactureButene Co-polymer for producing polyethylene and

PolypropyleneMethyl Tertiary Butyl Ether (MTBE) Blending in gasoline for increasing octane

number and oxygen contentFood Grade Hexane (FGH) Solvent for oil seed extraction.

Glues/Adhesives for foot wear Polymerization reactions in industries like Pharmaceuticals & printing ink. Retreading of car tyres

Sulphur Sulphuric acid and tyre manufacture

GUJARAT REFINERY (A Mother Industry)

IPCL NIRMA IFFCO GSFC

LAB, Cracked LPG LAB Naphtha Benzene, Sulfur,Naphtha, FGH Naphtha

Gujarat Carbon Chemical Ind. Aluminium Ind. PowerPlants

BUTENE-2 Toluene LARO LSHS

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PDFFGH

SRUGAS

SUSULLPHURPHUR

N-HEP/LARO

HEXANE(FG)

SG CRUDE

NG CRUDE

BH CRUDE

CRUDE DISTILLATION

UNITS I-V

CRUUDEX

MTBE

BENZENE TOLUENE XYLENE REFOR. LPG

NAPHTHA

MSSK/ATF

IMP CRUDE

RCO

VACUUM DISTILLATION

UNITS I-3

VGO

FLUIDIZED CATALYTIC CRACKING

UNIT

H2U-2

DHDS

HSD

VBU

H HYDRO2

LDO

LSHS / FO

IndianOil

BlBloocckk ffllowow ddiagriagraamm ooffGGuujajarratat RRefiefinneerryy

H2U-1 H2

CRACKER UNIT

VR

BBU BITUMEN

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2. GUJAR A T RE F INERY S E C O ND A RY PROC E SS I N G F A CIL I T I E S (G R SPF)

2.1 FEED PREPARATION UNIT (FPU)

INTRODUCTION: Feed P r e p a r a t i o n U n i t ( FPU), a p a r t o f G u j a r a t R e f i n e r ySecondary 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/year of vacuum gas oil for feed to FCCU along with vacuum diesel and vacuum residue. Later on, 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 also revamped, 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 pump around 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. The Slop Distillate mixes with Vacuum Residue downs tream of MP steam generator or cooled in slop distillate cooler and sent to GRE FO Pool.

2.2 FLUIDIZED CATALYTIC CRACKING (FCC)

INTRODUCTION: During 80's with increased processing of the North Gujarat and Bombay High Crude’s, the production of LSHS had gone up. This increased production of 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 steep increase in the prices of crude oil and petroleum products in the past few years and government’s policy of conservation of petroleum energy has changed the situation totally and it became necessary to review the utilization of LSHS more economically and profitably.

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 a capacity of 1 MMTPA.

HISTORY OF FLUIDIZED CATALYTIC CRACKER: Cracking is a phenomenon 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 more stable molecules leave the system as cracked gasoline and reactive ones polymerize forming 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 boiling ranges 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 over Thermal cracking viz.1) Catalytic cracking gives more stable products2) For corresponding yield and quality of gasoline, catalytic cracking unit operates under

less severe conditions3) 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 of chamber / 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.

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 “Thermofor Cracking”; “Thermofor Catalytic Cracking” and “Houndry Airlift” processes. In the Thermofor Catalytic cracking, the palletized catalyst was conveyed between the reactors and regenerator by means of Bucket Elevators. Higher investment by capacity limitations of Elevators/Air lift systems together with other engineering and process difficulties led to the development of latest concept in moving bed catalytic cracking i.e.

Fluidized Catalytic Cracking.

FLUIDIZED CATALYTIC CRACKING: The radical development was made by Standard Oil Co., New Jersey, M.W.Kellogg and UOP in early 1940’s in which the catalyst in the form of fine powder was held in suspension in gas stream. It was found that by carefully controlling the catalyst particle size and the velocity of gas moving through 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 is complete, 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 it indicates the coke-forming tendency of feed. Values for good cracking feedstock are0.2% 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 volatile and 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 any refining 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:

C2H4C6H6

Gas oil feed à Iso-octane branched paraffin(30 - 50 C atoms) CetaneCoke(60 % aromatics)

Catalytic cracking reactions produce unsaturated short chains like ethylene, excellenthigh-octane components like benzene and iso-octane and lower molecular weight gas oils like cetane. During cracking, apart from basic reaction of breaking of big molecules to small ones, other reactions like isomerization, cyclization, alkylation, polymerization etc also take place.

CRACKING CATALYST: The catalyst used in catalytic cracking process is a fine powder 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 priced hydrocarbons. 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 componentsf) Fuel oil components

PROCESS: FCC consists of three sections:1) Catalyst section2) Fractionating section3) 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. The raw oil from the surge drum passes through a series of heat exchangers where it gets heated against hot products i.e. heavy naphtha, LCO, HCO, CLO and slurry. The temperature 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 regenerator vaporizes 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 meets the 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 to form 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 over cracking and coke formation. Catalyst and oil contact time using this system is approximately 3 seconds. Catalyst and hydrocarbon vapors exit the riser into the reactor through the down turned disengaging arm. The disengaging arm provides the quick method 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 and enters 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 it flows 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 the regenerator coke is burnt off with controlled combustion air. Air from air blower is sent to 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 catalyst temperature to 640 - 660 deg. C range. This hot catalyst supplies heat to

the reactor. The catalyst 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 problems and 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 and leaves 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 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 (130-140ºC) 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 lighter and 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 to pick-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 circulation, which is based upon the principal of ‘Thermosyphon’.

The furnace where the combustion of fuel takes place is an integral part of the boiler. The boiler 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 unit are gasoline and LPG. After these products are separated through fractionation and stabilization section, they are given some chemical treatment like caustic wash and water wash to remove the impurities still present.

Safety Theme; Construction Safety 2

FCC FLOW DIAGRAM

Flue Gas

Catalyst seperation

Regenerator

2.5 Kg/Cm2

680 0 C

650 0C

Air

1000 T/hr

Oil Feed 3500C170 T/hr

Product

4900C 2Kg/Cm2

Stripping Steam

Ug = 0.1 - 0.3 m/s

Catalyst Seperation

3-5 Sec.

Typical Yields

DG = 3.0%LPG = 11.0Gasoline = 25%H.Nap =11%TCO = 33%CLO = 13%Coke = 4%

Density = 80 Kg/Cm2

Following chemicals are used in FCC/GCU:

1. Caustic Soda.2. Tri-Sodium Phosphate3. Hydrazine4. 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 down operations. Solid TSP is received in gunny bags. Required quantity of TSP is added to chemical 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 is5%.

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 + N2

23 % 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 is provided 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.

3. GUJARAT HYDRO-C RACKER UNIT (GH C)

3.1 HYDROGEN UNIT

INTRODUCTION: Gujarat Hydrogen plant with a capacity of 38000 tonnes per annum

and producing 99.99% pure hydrogen has come up as a part of Gujarat Hydrocracker Project. Hydrogen is generated in this unit by steam reforming of naphtha employing M/s LINDE’S technology. Hydrogen generated in the plant is consumed in Hydrocracker unit for various chemical reactions. These reactions need very high purity hydrogen to maintain requisite partial pressure of hydrogen in the Hydrocracker reactor. The fall purity 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 Removalh) 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 shift conversion, 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 to other units for consumption. The unit is unique in the country due to following:

k) 10 bed Pressure Swing Adsorption (PSA) system for the purification ofHydrogen product.

l) Special design of steam reformer involving use of low pressure and low calorific value 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 of hydrocarbons is sensitive to poisoning by sulphur compounds. Typically the sulphur concentration 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. thiophene mercaptanes, to hydrogen sulfide, which is then removed by an absorbent.

The hydrogenation reaction for conversion to hydrogen sulfide is achieved in a reactor, bed of cobalt-molybdenum catalyst or nickel-molybdenum catalyst.R SH + H 2 RH + H2S‘R’ is radical; it may be CH3, C2H5

Hydrogen sulfide reacts with zinc oxide to produce zinc sulfide and water according to 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 produce the sulfide ion and water. The water must diffuse away from reaction zone, while sulfide ion 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 steam reforming process is to extract the maximum quantity of hydrogen held in water and the hydrocarbon 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 gas

o) Hydrogen and carbon monoxide for oxo-alcoholsp) Hydrogen for refineries hydrogenation reactions and q) Reduced gas for direct reduction of iron ore.

The reforming of Natural Gas utilizes two simple reversible reactions:r) The reforming reaction CH4 + H2O » C O + 3H2

s) The water-gas shift reaction. CO + H2O » C O 2 + H2

The 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 be brought 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 reforming reaction along with side reactions is as under:

CnHm + nH2O nCO + (No Details+ m/2) H2---------(i)CO + 3H2 CH4 + H2O-----------------------------(ii)CO + H2O CO2 + 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 is reacted with excess steam to produce addition hydrogen and carbon dioxide. This is 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.

4.2 HYDROCRACKER UNIT

INTRODUCTION: Residue up gradation into middle distillates and light distillates is currently 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 coke is 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 to be 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 these problems 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 catalyst to 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 can produce LPG, Naphtha, ATF, Diesel in varying proportions as per design requirement. Primary function of Hydrocracker unit is to maximize middle distillate production in Gujarat 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 just before regeneration is called EOR operation.

FEED: Feed consists of VGO from FPUPRODUCTS: The primary products from HCU are:

t) L.P.Gu) Stabilized Light Naphtha v) Heavy Naphthaw) Aviation Turbine Fuel (ATF)/ Superior Kerosene (SK)x) High Speed Diesel (HSD)

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 are recovered/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 “FPU” and heated in exchangers and brought to the pressure of 185 Kg/sq.cm by feed booster pumps. 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. C before 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 Hydrogen Rich gas is recycled back to the reactor. The liquid product from the separator flows through 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 and lighter products.

2) SECOND STAGE REACTOR SECTION: Converted feed from the first stage reactor 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 345Deg. C before it is sent to the reactor. This reactor also contains three catalyst beds with two 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 to Hot 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 Pressure Separator (CHPS).

3) FRACTIONATION SECTION: Liquid from “HLPS” is heated in the exchangers and 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 146Deg. 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. The bottom 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 from fractionator after cooling in exchanger and cooler. The bottom of the vacuum column is feed for second stage reactor.

4) LIGHT ENDS RECOVERY SECTION: Light Naphtha from the fractionator is sent to de-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. The bottom 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 required to 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 of electrical conductivity of 50 - 450 Ps/m. The dosing is done in the ATF rundown line downstream 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 someof the rings share two or more carbon atoms, the compounds are referred to a condensed ring, 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 produce smoke when burned so they make poor jet fuel. Aromatics have good antiknock properties and make excellent high-octane gasoline.

2) Naphthenes- They are ring compounds without any benzene nuclei. The rings are typically five or six membered saturated rings. Naphthenes have intermediate API gravities and burning qualities.

3) Paraffins- They are straight chain or branched-chain. Straight paraffins are called normal paraffins and 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 an otherwise 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 long underground aging process in which crude oil is formed. Olefin can be formed as reaction intermediates during hydrocracking, but the high hydrogenation activity of the catalyst prevents any olefins from showing up in reactor products. Hydrocracker feeds also have lesser amounts of molecules, which contain chemically bound sulfur or nitrogen atoms in aromatic 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 olefin intermediates 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. The acid sites provide the carbonium ion intermediates and the isomerization activity that result in the dominance of isoparaffin products. More acidic catalysts produce a lighter yield 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 two separate reactions.The cracking of DMDS:

CH3-S-S-CH3 + 3H2 à 2CH4 + 2H2S

Followed by the sulfiding proper:

2H2S + 3 NiO + H2 à Ni3S2 + 3 H2O.

CATALYST REGENERATION:

Catalyst Regeneration consists primarily of burning off accumulated coke on the catalyst during the oxidation phase:

4C1H1 + SO2 à 4CO2 + 2H2O

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

Ni3S2 + 4O2 à NiSO4 + 2NiO + SO2,

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

3NiSO3 + 10H2 à 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 à Ni + H2O

5.2 VACUUM DISTILLATION UNIT (VDU)

INTRODUCTION: The Vacuum Distillation Unit (VDU) was designed to process8,00,000 TPA of RCO (370°C + 50:50 North Rumaila & Arab Light). After low cost1999 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 a provision 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 processing imported crude (50: 50 mixture of North Rumaila and Light Arabian Crude Oils). However, RCO obtained from various imported crudes and indigenous crudes (Bombay High, 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 Vacuum Residuum (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 FCCUalong 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 can be 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 305°C in case of hot feed and up to292°C 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 -398°C is maintained. The partially vaporized RCO is introduced in flash zone of column. LP steam superheated up to 350°C 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 and is fractionated into two side withdrawals.

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

preheating feed, a quench stream is routed back to the column to maintain bottom temperature of 355°C 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 150°C.

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 is removed 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.

5. LINEAR ALKYL BENZENE (LAB)

LAB plant has seven units:

1. Prefactionation Unit2. Distillate Unionfining Unit3. Molex Unit4. Hot Oil Unit5. Pacol Unit6. PEP Unit7. DETAL Unit

Process Flow Of Pre Fractionation UnitThe feed to this unit is straight run kerosene containing c-7 – c-17 hydrocarbon. The unit contains two columns

1. Stripper Column2. Return Column

6) Heated fed is introduced into the stripper column; lighter boiling kerosene fraction rich c-7 – c-9 paraffin is separated from the top.

7) The net column bottom is pumped into the rerun column.8) The rerun column fractionate the stripper column bottom into kerosene heart cut c-10

- c-17 paraffin.9) The column is operated under the vacuum by vacuum pump.10) Kerosene heart cut c-10 – c-13 normal paraffin are used as feed for the

UNIONFINING unit.11) Kerosene heart cut c-14 – c-17 normal paraffin are collected from the bottom of

the rerun column. These paraffin are reboiled and recycled to the column.

Distillate Union Fining Unit

6) Petroleum fraction contains various amount of naturally occurring contaminants including organic, sulfur, nitrogen & metal compound.

7) Feed to the MOLEX unit is nitrogen & sulfur free.8) The process does saturating olefins & aromatic compound reducing Conradson carbon.9) Removing other contaminants such as oxygenates & organo metallic compound.10)The feed for the unit is taken from kerosene heart cut from fractionation unit.11)The unionfining process is fixed bed catalytic process developed by UCP for

hydrotreating a wide range of feedstock.

12)Process uses a catalytic hydrogenation method to remove the sulfur, nitrogen , aromatics, metal , halide etc. to < 1 ppm level with a negligible effect on the boiling range of the feed.

13)Treated heart cut to MOLEX unit is product.14)Unionfining is carried out at elevated temp & pressure in a hydrogen

atmosphere pressure & temperature are in the range of 92.50 Kg/cm^2 & 325 deg. C.

15)Catalyst consist of oxides of nickel & molybdenum impregnated on an alumina base.The catalyst is be either as sphere or extrudate with special shapes.

Mol ex Unit

The UOP MOLEX process is an effective method of continuously separating normal paraffins from a stream of co- boiling hydrocarbon.The feed stock is separated into a high purity normal paraffin fraction at high recoveries and a non-normal paraffin.The process simulates counter-current contact between a fixed bed adsorbent &the feed stream.It uses a solid adsorbent, liquid desorbent and flow directing devices called the“CMI” or “Coplanner Manifolding Indexer”.Feed consists hydrotreated kerosene ( c10-c13).The extracted normal paraffin to the pacol unit is the product.The feed is then sent through the CMI to the adsorbent chamber. The chamber has a seven stream.The stream entering the chambers are the feed, desorbent, zone flush, flush line in.The stream exit, the chambers are extract, raffinate & flush line out. After the CMI chamber feed comes in Extract & Raffinate column.Form the Raffinate column non-normal paraffin is separated from the desorbent. From the extract column, normal paraffin is separated from the desorbent.

Pacol U nit

The pacol section is fixed bed catalyst process to selectively dehydrogenate a high purity, normal paraffin feed to mono-olefin product.Catalyst should be selective for reaction like cyclisation; skeletal isomerization diolefin product & cracking are minimized by proper operating condition.Pacol involves following step: Paraffin converted to olefins. Diolefin removal.Light end removal by fractionation.

4) Reaction is promoted in a low pressure.5) CATALYST: DEH 11.

It contains:1. Platinum< 1wt%

2. Silicon oxide 40-60 wt%3. Aluminium oxide 40-60 wt%

Life: 6 to 7 tons LAB/Kg of catalystFeed: ParaffinProduct: c10-c13 or c11-c14 mono olefins.Process conditions are temperature sh0uld be 450-500 deg. C & pressure should be1.5 Kg/cm^2.

Pacol Enhancement Process (PEP)

dd) PEP is fixed bed adsorption unit for the selective removal of aromatics from the pacol product stream.

ee) The primary source of aromatics in the pacol product.1. Aromatics in the fresh n-paraffin feed to the pacol unit.2. Aromatics produced in the pacol reactor.3. Light alkylate in the recycle paraffin from detal unit.The feed to the PEP unit l stripped c10-c13 linear paraffin & olefin from pacol unit.The feed passes through adsorbers where most of the aromatics are removed & the treated feed then leaves the unit & goes to detal unit.Benzene (desorbent) comes into unit passes through adsorber on the desorption cycle & goes to the desorbent column.The overhead of the desorbent column goes to the detal unit.Pentane from the depentanizer overhead passes through adsorber a purge cycle and return to the depentanizer column.

Detergent Alkylat ion (Detal)

5) Reacting treated from PEP & bezene using heterogeneous non-corrosive catalyst to form LAB produces LAB.

6) The dtal process is a catalytic process to alkylate benzene with linear olefins to form linear benzene.

7) LAB (linear alkyl benzene) is main product, HAB (heavy alkylate benzene) is byproduct.

8) LAB & HAB are surface-active compound (surfactants) which combined with various builders to make up a detergent formula.

Oil Movement an d Storag e ( O M & S)

The objective functions of OM & S are follows:11)To receive crude oil and uninterrupted to supply to processing unit after

proper accounting and tank operation.12)To receive intermediates and finished product streams to unit to prepare

quality product in a safe and environment friendly manner.13)Timely supplying the quality products to the marketing as per the palning

and schedule to meet the market demand.14)To meet the saturatory requirement of central excise & customs w.r.t crude

and petroleum product storage and movement.15)To maintain safe and pollution free environment. To strive for internal and

external customer satisfaction.16)To conserve energy by losses.17)To ensure safety of personnel and equipment by adopting safe practices.18)To continuously upgrade and asses the knowledge and skills of operating personnel.

D isp at ch of Produc t s in Guja rat R ef ine ry:

4) A product becomes ready for dispatch only after getting the quality certificate from laboratory and after complying with the necessary excise formalities.

5) There are three modes of transport operating in the refinery for the dispatch of products.

1. Pipeline2. Road3. Rail

1. Dispatches by p i p e l i n e :

Product by pipeline is dispatched to the following

destination. a. IPCL, Jawaharnagar, Vadodara-LAB,

Naptha, LSHS.b. GSFC, Fertilizernagar, Vadodara –LSHS.c. Sabarmati installation of IOCL near Ahemdabad – MS, SK, ATF, HSD.d. Other marketing companies, terminal at Nandesari, Vadodara – MS, SK, HSD. e. GIPCL, Vadodara-Naphtha.f. LAB to Nirma.g. MS/SKO/HSD dispatch to IOTL, Dumad. h. MS/SKO/HSD dispatch to KNPL.i. FO/LDO dispatch to ASOJ terminal. j.

LPG to Dumad terminal.

2. Di s p at c h e s by r o ad :

The following products are dispatched by

roads. a. Toluene.b. Mineral turpentine Oil. c. ATFd. Food Grade Hexane. e. Naphthaf. Army HSD.g. Light diesel Oil. h. Furnace Oil.i. LSHS.j. Bitumen.k. Butene- 1&2l. Light Aluminium Rolling Oil. m. IOC Solvent -90.n. HCU Bottom. o. MTBE.p. LAB-LMW q. LAB-HMW r. N-Paraffins. Heavy Alkylatet. Off – spec LAB.

3. D ispa tches by rail

The bulk of dispatches from this refinery moves by rail. For this reason elaborate facilities have been provided for this mode of dispatch.The following product moves by rail.

a. Naphthab. LPG (both bulk and packed)c. Motor Spirit (N-MS and X-premium)d. ATFe. Kerosenef. Diesel (Army, N-HSD)g. Light Diesel Oil h. LSHSi. VGOj. Bitumen