PRESENTATION ON INPLANT TRAINING AT MRPL

Mangalore Refinery and petrochemicals Limited is a subsidiary of ONGC. It is located north of mangalore city, in Dakshina Karnataka region, set

amidst a stunning hilly terrain. Before acquisition by ONGC in the year 2003,MRPL was a joint venture

Oil refinery promoted by Hindustan Petroleum Corporation Limited and AV Birla group

VISIONTo be a world-class Refining and Petrochemicals Company, with a strong emphasis on Productivity, Customer Satisfaction, Safety, Health and Environment Management, Corporate Social Responsibility and Care for Employees.

MISSION

Sustain Leadership in energy conservation, efficiency, productivity and innovation.

Capitalise on emerging opportunities in the domestic and international market.Strive to meet customers’ requirements to their satisfaction.

Maintain global standards in health, safety and environmental norms with a strong commitment towards community welfare.

Continuing focus on employee welfare and employee relations.Imbibe highest standards of business ethics and values.

Naphtha Stabiliser

CDU

VDU

Naphtha Splitter

Kero/ATF Splitter

CRUDE

O/H Stream

HN

RFN

Kero/ATF

LGO

HGO

VDOLVGO

HVGO

SR

Kero /ATFMEROX

LN O/H

FG

LPG MEROX

GOHDS

Vac Slop

Hot wellOG/OIL

UNIT CONFIGURATION

1.CRUDE DISTILLATION UNIT FEED: Crude oil PRODUCTS: LPG, Naphtha, Diesel, Kerosene Crude distillation unit is the first processing unit and is also called the

mother unit. The CDU is divided into two main categories1) Heating and desalting the crude2) Distillating or separating the crude into fractions The CDU is often referred as atmospheric distillation unit because it

operates at slightly above atmospheric pressure.

The various processes involved are1. Crude desalting2. Preheating3. Crude heating4. Fractionating

Naphtha Stabiliser

CDU

VDU

Naphtha Splitter

Kero/ATF Splitter

CRUDE

O/H Stream

HN

RFN

Kero/ATF

LGO

HGO

VDOLVGO

HVGO

SR

Kero /ATFMEROX

LN O/H

FG

LPG MEROX

GOHDS

Vac Slop

Hot wellOG/OIL

UNIT CONFIGURATION

Number of trays - 56 Type of trays - Valve trays Stripping section-upto 10th tray Top of the flash zone rectification section Number of chimney trays - 6 Feed tray - 10th tray heavy naphtha draw – 44th tray Kero draw – 31st tray

2.VACUUM DISTILLATION UNIT

A secondary refining process in which straight-run residue is distilled in a vacuum in order to separate more light hydrocarbons than through atmospheric distillation.

The output of the process is vacuum gas oil, which can be used as feedstock for cracking units, and vacuum bottoms or residue, which are usually used as boiler fuel.

Vacuum distillation column is divided into three sections1) The top section2) The middle section3) The bottom section Here, chimney trays are used to draw products since downcomers

cannot be used for packed column. The streams coming of the column is of 3 types1) circulating reflux2) Internal reflux3) Product streamDemister pads are provided to trap entrained droplets.

M.P. Steam

Ejector 370 CR

VDO370 IR

S.R. Recycle. C.W. L VGO C.R.

LVGO Product. Reduced crude oil LVGO I.R

HVGO Product. HVGO I.R. Sour water

VS

VDU Heater.

Sort residue.

f

Hot well Hotwell offgas

It increases the relative volatility therefore making components more separable thereby lessening the number of stages required.

There is also reduced temperature requirement at lower pressures hence preventing product degradation by polymer formation.

It also reduces the mean residence time by using packings rather than trays and packings reduce pressure drop.

Products• Vacuum diesel oil (VDO) is lighter product in vacuum column• VDO process to GOHDS to remove sulfur• May have multiple gas oils

• Separate products to increase the heat recovery in the column• Products recombined downstream • Feed for hydrocracker

• Vacuum residue• Further processing – thermal cracking (VBU) and BBU• Blended with cutter stock to make fuel oil• Choice depends on products & crude

3.HYDROCRACKER UNIT

FEED: VGO PRODUCTS: LPG, NAPTHA ,DIESEL,ATF,LSHS

Hydrocracking is a process for catalytically hydrocracking heavy petroleum fractions in to lighter fractions and more valuable products.

The feed is converted into lower molecular weight products ,usually maximising naptha or middle distillate.

The desired degree of hydrocracking takes place as the feed passes over fixed beds of catalysts in a hydrogen atmosphere at high temperature and pressure.

The amount of catalyst and the operating pressure and temperature depends upon the quantity and nature of feed being processed and the desired products.

In addition to hydrocracking several other reaction occurs in the hydrocracker such as

1) Desulphurizaton2) Denitrogenation3) Oxygen removal4) Halides removal5) Olefin separationDesulphurization is the most rapid reaction but saturation of olefin rection liberates the greatest amount of heat. Products are a mixture of pure paraffins, napthenes and aromatics.

The various units present are1) Reactors2) Combined Feed Exchangers3) High pressure separator and low pressure separator4) Recycle splitter5) Recycle splitter feed heater6) Sponge absorber7) Heavy naphtha splitter8) Kerosene splitter9) Diesel splitter10) Gasoline stabilizer column11) Amine absorber

4.HYDROGEN UNITThis unit deals with the production of hydrogen gas which is utilized by several other units such as Hydrocracking unit and Gas oil hydrodesulphurization unit.The process used here is steam reforming of naphtha and the product obtained is 99.99% pure hydrogen.The naphtha from HCU is fed into feed surge drum and then fed to a heater having 3 fuel gas fired burners to heat the fed.This is then sent to a COMOX reactor followed by a ZnO reactor where the following reactions occurCOMOX Reactor: RSH + H2 RH + H2SZnO Reactor:ZnO + H2S ZnS + H2O

The effluent of ZnO reactor is sent to a reformer consisting of 192 tubes containing potash bearing nickel catalyst along with nickel catalyst and 75 burners.

The high temperature outlet is used for stem generation and cooled in a process gas boiler and a steam of temperature of about 633K is obtained which is mixed with the product stream of ZnO reactor in High temperature shift gas reactor.

The process gas obtained is then passed through pressure swing absorbtion unit which is a series of 10 absorbers consisting of 5 beds each.

This is followed by a series of 3 exchangers, hot and cold seperator

The absorber consist of Extrudes, molecular sieves, activated carbon, silica gel and activated alumina which remove gases such as CO, C, CO2,and moisture and the product gas coming out of the vessel is about 99.99% pure hydrogen

5.GAS OIL HYDRO DESULPHURIZATION UNIT

The feed consists of light gas oil and heavy gas oil and is obtained from Crude Distillation Unit or from storage.

The feed after passing though feed filter and feed surge drum is passed into a series of two reactors through a multistage pump and combined feed exchanger .

The first reactor consists of both COMOX and NIMOX catalyst whereas the second reactor has only NIMOX reactor.

A balanced draft heater is provided between combined heat exchanger and reactor1 to increase the temperature of the feed at the inlet of the reactor.

The effluent is then sent into a hot separator.The gas separated in the hot separator is sent to a fin fan cooler and water cooler followed by cold separator where the gas is sent to amine absorber.

The liquid from hot separator and cold separator is sent to a stripper consisting of 24 trays. The product obtained is purified further to obtain diesel.

The function of NIMOX catalyst is denitrification whereas COMOX is mainly associated with desulfurization.

The reactor bed is also provided with rashchig rings and ceramic balls.

The removal of moisture from diesel is done using coalasers and salt filters consisting of rock salts.

The product obtained consists of about 30-40% moisture.

6.MEROX UNIT Introduction

Types of merox

Chemical reactions

Process description

Process flow diagram

Introduction The merox process is an efficient and economical catalytic process

developed for the chemical treatment of petroleum distillates for the removal of sulphur present as mercaptans,by converting the mercaptan as disulphide oil in the presence of air.

Mercaptan is a sulfur compound designated as RSH where R is an alkyl radical attached to Sulfur which is attached to Hydrogen. These compounds can be toxic and are highly corrosive leading to the need of their removal.

The name “Merox” originates from the functi of the process itself,namely the conversion of mercaptans by oxidation.

MRPL processes 261MT/day in LPG Merox and 2181MT/day in Kero Merox.

Types There are two types of merox treatments possible. They are Extractive Merox and Sweetening Merox. Extractive Merox: This process reduces the sulphur content of LPG

products to meet specification by extracting out the mercaptans from the LPG/ Gasoline streams

Sweetening Merox: This process converts the mercaptans present in the hydrocarbon stream into harmless disulphide oil in the presence of air.Thus keeping the total sulphur in the hydrocarbon stream as disulphides.Hence this process is know as sweetening process.

Chemical reactions Chemical reactions involved in the Mercaptan oxidation are: Extraction Merox: 4RSH+4NaOH 4NaSR+4H2O 4NaSR+O2+2H2O 4NaOH+2RSSR Sweetening Merox: 4RSH+O2 2RSSR+2H2O

Process description Extraction Merox: Extraction Merox is also known as LPG Merox. LPG from CDU& VDU is sent to amine treatment. The LPG from amine treatment is sent to prewash column. where prewash is done with 10 Be NaOH solution which brings down the H2S

concentration to below 10ppm. Next the feed is sent to Extractor having sieve trays. Here Mercaptans react with 20 Be NaOH solution to form NaSR. Next it goes to caustic KOD and to the sand filter for NaOH recycle. NaSR is oxidized in the presence of Merox F.B catalyst where it forms disulphide oil. Disulphide oil is separated from the LPG in disulphide oil separator. Thus the LPG of required specification is obtained.

Sweetening Merox: Sweeteninig is also known as Kero Merox. Kerosene is sent to electrostatic coaleser where kerosene reacts with

30Be NaOH solution which removes traces of H2S and mercaptans dissolve in NaOH.

In mixer air gets mixed with kerosene. This mixture is fed to the fixed bed reactor where merox F.B catalyst

is impregnated on activated charcoal,here Mercaptans are converted into disulphides.

The mixture is sent to causticsettler,waterwash,saltfilter and then to clay filter to recycle the caustic.

The kero Merox product is then sent to storage tanks.

7.ISOMERISATION UNIT

Isomerisation is a chemical process where one molecule is transformed in to another with the same molecular formula but with the different arrangement of atoms

Reaction takes place is n-paraffinsisoparaffins

Objective:The main objective of isomerisation unit is to produce high octane,low

aromatic gasolineFeed:Light naptha receiving from CDU,hydrocracker,RSU,storageOverall process is divided in to 3 sections Light naptha hydro treater unit(LNHT) Bensat section Penex section

Light naptha hydrotreater section(LNHT):Feed→ CFE→ heater→ reactor→ pinfanncooler→ stripper Reactor:Reactants: feed+hydrogenCatalyst: comoxUsed to remove impuritites from the feed(sulphur→H2S,nitrogen→ammonium chloride) Stripper: 30 traysCondensed liquid feed is inserted in the 29th tray &MP steam is inserted

from the bottom of stripperFrom the top of stripper we can obtain c1 to c4 & also H2SFrom bottom of stipper we can obtain C5 to C7

Depentanizer :Bottom stripper→depentanizer.The bottom product of depentanizer is sent to bensat sectionBensat section:Here benzene is converted to cyclohexanes in a bensat reactorCatalyst:H8methanater:CO→CO2→CH4

Penex section: The feed from bensat section is sent to feed and gas driers→to

moisture content Penex reactor: Feed from the driers goes to penex reactor catalyst –platinum and base is aluminium oxide promoter: perchloroethyleneThe following reaction takes in the reactori. C7→C3&C4ii. C5→isopentanesiii. hexanes→2,2 DMB 2,3 DMB & 2MP ,3MP

Stripper section:From reactor→stabilizerBottom:2,2 DMP 2,3 DMP 2MP 3MPTop product: c1 to c4 streamDi-isohexanizer:(80 trays)Stripper bottom→di-isohezanizerTop product:2,2 DMP 2,3 DMP(light isomer)RON:91Bottom liquid:heavy isomerateRON:73Side drop: 2MP 3MPSide drop is mixed with feed and sent as feed

Product specifications: Benzene % is zero Sulphur % is zero RON is 91 Density is in the range of 0.65 Licensor:UOP

8. CATALYTIC REFORMING UNIT Main objective

boosting Naphtha Octane number from ~63 to ~105

Process Licensor : M/s UOP Desplaines

Technology: Continuous catalytic regenerating Reformer

Installed Capacities: CCR1&2 : Each 0.384 MMTPA (64 m3/hr)

Commissioning : CCR1 - 1996 / CCR2 - 1999 Typical Yields : Reformate = 85 -87%

LPG = 2 - 3%Net Gas = 10- 12 %

Main sections: Naphtha Hydrotreater Platformer Continuous Catalytic Regenerator Debutanizer Net gas purification (PSA unit)

Naphtha Hydrotreater

Objective: Platformer Feed treatment by Hydro-desulfurisation Hydro-denitrification Removal of Oxygen from the feed Olefins Saturation Removal of feed metals

NHT Reactor parameters

Catalyst :CoMox + NiMox (S12H by UOP)

Temperatures : SOR 311ºC / EOR 343ºC

System Pressure : 35 Kg/cm2G

Hydrogen to Hydrocarbon ratio:80-100 NM3/M3

Feed Naphtha

Recycle H2

HT naphtha to Platformer

Sweet Naphthato storage

Sour water

NHT Reactor

Stripper

Separator

Stripperreboiler

Chargeheater

Reflux

Ovhd condensorCRU: Naphtha Hydrotreating section

Platforming Reactors Consists of Four Reactors stacked in series for

continuous catalyst gravity flow, with Interheaters for feed pre-

heating

Hydrotreated Platformer Feed Naphtha quality Total Sulphur 0.5 ppm Max Total Nitrogen 0.5 ppm Max Total Chloride 0.5 ppm Max Bromine No <1 Moisture <0.5ppm

Platforming CatalystBimetallic Catalyst : UOP R-134Shape & size : spherical, 1.5 mm dia Ingredients : Platinum with promoting

metal dispersed on high purity chlorinated Alumina

support.

Metal function : Platinum (0.2 - 0.6 wt%)Metal promoter : Rhenium (0.03 - 0.7 wt%)

Chloride levels : 1.0 - 1.3 wt%Regeneration type : Continuous catalyst

regeneration (CCR)Main regen. steps : Inerting, Dust removal, Burning,

Oxy-chlorination, drying, reduction

PLATFORMING REACTIONS Dehydrogenation of naphthenes CH3 CH3

+3H2

Methyl cyclohexane Toluene C7H14 C7H8

Volume gets reduced. Reaction is endothermic,very fast, favored by low partial pressure

• Isomerisation & dehydrogenation

CH3 +3H2

Methyl cyclo Benzene pentane MCP first isomers to hexane and then dehydrogenates to

benzene.Volume gets reduced.

• Dehydrocyclization

C-C-C-C-C-C-C CH3 +H2

Here volume gets reduced.The reaction is favoured by high temperature and low pressure. This reaction predominantly takes place in 3rd reactor.

PLATFORMING REACTIONS - contd.

• Hydrocracking

C-C-C-C-C-C-C+H2 C-C-C + C-C-C-CN-Heptane Propane ButaneC7H16 C3H8 C4H10

High pressure and temperature accelerates Hydrocracking, is Exothermic.

PLATFORMING REACTIONS - contd.

CRU: Platformer sectionCatalystfrom Regenerator

Catalystto Regenerator

R1

R2

R3

R4

Packinox

RGC

HT Naphthafrom Stripper

bottoms

CHIH-1IH-2IH-3

Reformateto Debutaniser

H2 to header

PSAunit

Tailgas to FG

Separator

Net gasrecontactsection

CCR section

Surge hopper

Flow control hopper

Disengaging hopper

Nitrogen

AIR

Chloride

Regen. Blower

Chlorination ZoneBlower

Regen. Heater

Air heater

RegenTower

Catalyst from Reactor-4 bottom via Lock hopper-1 & Lift Engager-1

Chlorination ZoneHeater

Catalyst to Reactor-1 top via Lock hopper-2 & Lift Engager-2

Regen. cooler

Coke burning zone

Oxy-chlorination zone

Drying zone

CW

Catalyst RegenerationMajor parameters Regeneration zone O2 content

To be controlled between 0.8 - 1.0 % Burn zone temp profile to be controlled completion of carbon burning in Regeneration zone itself

Catalyst circulation rate 300 Lbs/hr to 450 Lbs/hr, depending on catalyst LOI controlled by Flow control hopper timer.

Temperature controls Regenerator heater o/l : 477ºC Chlorination heater o/l : 510ºC Air heater o/l : 565ºCCatalyst analysis Spent catalyst Carbon content : 3-5 % Regenerated catalyst Chloride content : 1-1.3%

CRU: Debutaniser section

Liquid fromNet Gas

Recontact sectionReformate

to MS Blending

LPG to Chloridetreaters

HP steam

CW

CWOff-gas

IMPORTANT M.S. SPECIFICATIONS

PropertyCurrent MS

BS-2 (regular)

Euro-III (Reg)

Euro-IV (Reg)

Density @ 15ºC, kg/m3 0.71-0.77 0.71-0.77 0.72-0.775 0.72-0.775Final Boiling point, ºC 215 215 210 210RON, min 88 88 91 91Sulfur, max 0.10% 0.05% 150 ppm 50 ppmLead, g/l (max) 0.013 0.013 0.005 0.006RVP, Kpa (max) 35-60 35-60 60 60Benzene, % Vol (max) 3 & 5 3 & 5 1 1Olefin, % Vol (max) - - 21 21Aromatics, % Vol (max) - - 42 35Oxygen content, % mass (max) - - 2.7 2.7

Advantages of CCR Platformer

Low pressure operation Low LHSV & lower H2/HC ratio Higher reformate production Higher H2 purity Higher H2 yield Low catalyst quantity Uniform yield throughout the year Better for aromatics production Higher reliability & higher octane yield No need for addition of Tetra ethyl lead (lead is

nil in MS)

9.VISBREAKER UNIT

10.MIXED XYLENE UNIT

Xylene is the aromatic compound formed by substituting 2 hydrogen molecules in benzene ring.It can be ortho, meta or para position.

Technology provider: UOP, USA

Feed : Heavy reformate from CCR containing C7,C8,C9 hydrocarbons with traces of C4,C5 and C6 hydrocarbons.

The feed is sent to a reformate splitter in which C4,C5 and C6 hydrocarbons are removed at the top of the column. The C7,C8,C9 hydrocarbons are present in the bottom product. The bottom product is sent to a column in which the C7 hydrocarbons are removed at the top and is sent to be blended to obtain the require RON.The C8 and C9 hydrocarbons are obtained at the bottom and sent to Xylene column( 11 trays )From the top of xylene column the desired C8 hydrocarbon ( xylene) is removed and is sent to the storage tanks. The C9 hydrocarbon obtained from the bottom of the xylene column is sent to the blender for blending with gasoline.

11.BITUMEN BLOWING UNIT Bitumen is the heaviest fraction of crude oil.It is black in colour and is a highly viscous

liquid or a soft solid at room temperature.They are non-volatile and highly resistant to oxidation and weathering.

The process involve passing air bitumen feedstock at elevated temperature in order to change the physical properties of the products.The main purpose is to harden the bitumen and increase the softening point.The VR is subjected to oxidation by blowing compressed air through it at a temperature of 220-280 C in a blowing tower.

The general reaction pathway is the transformation of cyclic structures into resins(polar aromatics) which are in turn condensed to form asphaltenes.In bitumen blowing, the primary oxidative process is carbon-carbon bond formation via oxidative condensation.As the reaction proceeds , cyclic and resins that make up the oily phase are converted to asphaltenes resulting in hardening of bitumen and increase in softening point.

Bitumen/Asphalt is categorized into four types: Straight run, blown, cutback and emulsion. 1.Straight run bitumen is a black/dark brown high viscous solid material. Flashing at very high temperatures of the vacuum residue is required in order to produce this bitumen. There are two major characteristics of bitumen:

Softening point: It is the temperature at which an object with a standardized weight and shape will start to sink into the asphalt. Common practice is to use steel balls, which is what MRPL follows. Commercial softening points range from 80-340°F.

Penetration: Hardness of asphalt once load is applied. The range is from 0 (very hard) – 250 (very soft)2.Blown bitumen is produced by blowing hot air into softer grades of the asphalt causing a chemical reaction yielding more rubbery and harder asphalt.

Cutbacks are yielded from the addition of a thinner to the bitumen in order to reduce the temperature requirements giving softer asphalt. However after asphalt has been applied the thinner/diluent evaporates yielding a hard, durable asphalt.

Emulsion is a mixture of 50-70% bitumen and 30-50% water. The mixture remains mixed with the aid of an emulsifying agent, like soap.

MRPL only produces straight run and blown bitumen. The blown bitumen is produced in this Bitumen Blowing Unit (BBU).

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