Fundamentals of Refining Products and properties

7/22/2019 Fundamentals of Refining Products and properties

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A Sunrise Project for a Sunshine Future

PARADEEP REFINERY PROJECT

FacultyV SureshSPNM-CG

Prepared byProduction-CG Team


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REFINING

PARADEEP REFINERY PROJECTA Sunrise Project for a Sunshine Future

Distillation, the process by which oil is heated and separated in different

components, is the first stage in refining (primary processing).

Additional processes (secondary processing) ensures the desired products

are produced as per specification.


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FRACTIONAL DISTILLATION


The mixture can be split into simpler fractions by fractional distillation.


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CATEGORIES OF END PRODUCTS


The typical primary end-products are categorised as

Light distillates

Liquid petroleum gas (LPG)Propylene

Motor Spirit (also known as petrol)

Naphtha

Middle distillates

KeroseneATF

HSD (Hi-Speed Diesel)

LDO (Light Diesel Oil)

Heavy distillates

Heavy fuel oilsLSHS

Other Solid Products

Petroleum Coke

Sulphur


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CLASSIFICATION OF REFINING PROCESS



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DISTILLATION



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DISTILLATION


Distillation is based on the fact that the vapour of a boiling mixture will be

richer in the components that have lower boiling points.

When this vapour is cooled and condensed, the condensate will contain

more volatile components. At the same time, the original mixture will

contain more of the less volatile material.


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DISTILLATION COLUMN - TYPES


BATCH COLUMNS

The feed to the column is introduced batch-wise. That is, the column is

charged with a 'batch' and then the distillation process is carried out. When

the desired task is achieved, a next batch of feed is introduced.

CONTINUOUS COLUMNS

Continuous columns process a continuous feed stream. No interruptions

occur unless there is a problem with the column or surrounding process

units.

They are capable of handling high throughputs and are the most common of

the two types


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UNSTEADY STATE DISTILLATION


Previously used at Digboi Refinery


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DISTILLATION COLUMNEQUIPMENT


A typical distillation contains several major components:

a vertical shellwhere the separation of liquid components is carried out column internals such as trays/plates and/or packings which are used to

enhance component separations

a reboiler to provide the

necessary vaporisation for the

distillation processa condenser to cool and

condense the vapour leaving the

top of the column

a reflux drum to hold the

condensed vapour from the top ofthe column so that liquid (reflux)

can be recycled back to the column


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DISTILLATION PROCESS


The liquid mixture that is to be processed is known as the feed

Feed is introduced usually somewhere near the middle of the column to

a tray known as the feed trayThe feed tray divides the column into a top (enriching or rectification)

section and a bottom (stripping) section.

The feed flows down the column where it is collected at the bottom in

the reboiler.


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INTRODUCTION TO DISTILLATION WITH REFLUX


1. Feed enters the column somewhere in themiddle of the column.

5. The vapor continues up to the next tray or

stage, where it is again contacted with adownflowing liquid.

2. Feed is liquid, it flows down to a sieve trayor stage.

4. The vapor and liquid leaving the tray areessentially in equilibrium.

In a distillation column the stages (referred to as sieve plates or trays) in a distillation tower arearranged vertically, as shown schematically in figure below.

3. Vapor enters the tray and bubbles through

the liquid on this tray as the entering liquidflows across.

6. The concentration of the more volatile

component is being increased in the vapor

form each stage going upward and decreased

in the liquid from each stage goingdownwards.


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INTRODUCTION TO DISTILLATION WITH REFLUX


7. The final vapor product coming overheadis condensed in a condenser and a portion of

the liquid product (distillate) is removed,which contains a high concentration of A.

9. The liquid leaving the bottom tray enters a

reboilier, where it partially vaporized, and

the remaining liquid, which is lean in A orrich in B, is withdrawn as liquid product.

In a distillation column the stages (referred to as sieve plates or trays) in a distillation tower arearranged vertically, as shown schematically in figure below.

8. The remaining liquid from the condenser is

returned (refluxed) as a liquid to the top tray.

10. The vapor from the reboiler is sent backto the bottom stage or trays is much greater.


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DISTILLATION COLUMN



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DISTILLATIONTYPES OF LIQUIDS

PARADEEP REFINERY PROJECT

LIGHT liquids are composed of ________ molecules.

tend to vaporize ________

have _______ vapor pressureshave _______ boiling points

HEAVY liquids are composed of _________ molecules.

do not tend to vaporize ________

have _______ vapor pressures

have _______ boiling points

Volatility is a term used to refer to ease of vaporization. Hence, a liquid

which tends to vaporize easily has a high ____________.

A liquid with a high boiling point has _______ volatility.

A liquid with a high vapor pressure has _______ volatility.

A Sunrise Project for a Sunshine Future

small

easily

highlow

large

easily

high

low

volatility

low

high


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FLOW SCHEME OF MODERN REFINERY



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REFINERY CONFIGURATIONS

http://en.wikipedia.org/wiki/File:RefineryFlow.png


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FLOW SCHEME OF PARADIP REFINERY



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VARIOUS UNITS IN THE REFINERY


1.0 Atmospheric/ Vaccum distillation Unit (AVU) : distills crude oil into various

fractions first at Atmospheric pressure and them under vaccum.

Feed: Crude oil

Products /byproducts

Refinery off gas

LPG

Naphtha

Kerosene

Straight run diesel

Vaccum gas oil

Vaccum residue


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2. Naphtha hydrotreater unit (NHTU) uses hydrogen to desulfurize naphtha

from AVU and other units to feed the same to Catalytic Reformer unit

(CCRU).

Process : Feed hydrogen mixture heatingreaction ( over catalyst bed)

Separation and recycle of hydrogenstripping of liquid for H2S

product routing.

Feed

Naphtha from AVU

Cracked naphtha from FCCU

Products /byproducts Fuel gas

Hydrotreated naphtha


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3. Continuous Catalytic reformer unit (CCRU) is used to convert the naphtha-

boiling range molecules into higher octane reformate (reformer product).

The reformate has higher content of aromatics. An important byproduct of

a reformer is hydrogen released during the catalyst reaction. The hydrogen

is used for removal of sulhur in hydrotreaters.

Feed

Hydrotreated naphtha


Fuel gas - byproduct

ReformateMajor component of Petrol

Hydrogen - byproduct LPGbyproduct


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4. Distillate/ Diesel hydrotreater (DHDT)unit desulfurizes distillates (such as

diesel) after atmospheric distillation.

Process : Feed hydrogen mixture heating reaction ( over catalyst bed)

Separation and recycle of hydrogen stripping of liquid for H2S

vaccum dryingproduct routing.

Feed

Straight run diesel from AVU

Coker gasoil

FCC light cycle oil

Hydrogen

Products /byproducts Fuel gas - byproduct

Treated Diesel

Napthabyproduct


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5. Vaccum gas oil Hydrotreater unit (VGO-HDT)uses hydrogen to treat the feed

to FCC to remove sulphur and nitrogen compounds.

Process : Feed hydrogen mixture heating reaction ( over catalyst bed)

Separation and recycle of hydrogen stripping of liquid for H2S

Atmospheric distillation for Diesel separation product routing. Diesel is

further hydrotread to meet sulphur specification.

Feed

Vaccum gasoil (VGO) from AVU

Coker Hy gasoil

Hydrogen



Treated Diesel

Treated VGO

Napthabyproduct

LPGbyproduct


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6. Delayed coker Unit (DCU) process very heavy residual oils(vaccum residue)

into gasoline and diesel fuel, leaving petroleum coke as a residual product

by thermal cracking.

Process : Feed heating to high temperature Coking Separation of

distillate and gas. Coke removal and disposal. All products require

further treatment in secondary processing units.

Feed

Vaccum Residue from AVU



Coke

Gas oil

Coker naphta

Coker LPGbyproduct


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7. Fluid catalytic cracker (FCC) is used to convert the high-boiling, high-

molecular weight hydrocarbon fractions of petroleum crude oils to more

valuable gasoline, olefinic gases, and other products.

Process : Feed heating Cracking in presence of catalyst Separation of

distillate and gas.

Spent catalyst regeneration using air and recycle.

Feed

Vaccum Residue from AVU



Cracked LPGPRU

Lt NapthaMS blending component

Hy naphtha -

Cycle oils


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8. Alkylation unit and Butamer unit : produces high-octane component for

gasoline blending from FCC LPG feed.

Process : Feed Alkylation reaction in-presence of Sulphuric acid catalyst

separation.

Feed

FCC LPG and Straight run LPG ( C4 components)


Alkylate

Spent acid


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9. Sulphur recovery unit (SRU -Claus unit) and tail gas treatment convert

hydrogen sulfide from hydrodesulfurization into elemental sulfur.

Process : H2S rich gas from Amine regeneration unit Claus reaction

Sulphur separation.

Feed

H2S rich gas from ARU


Elemental Sulphur



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10. Amine regeneration unit (ARU)recovers /removes hydrogen sulphide from

rich amine and lean amine to sent back to absorbers

Process : Rich amine loaded with H2S from units stripper -> Lean amine

recycle to units and H2S to SRU.

Feed

Rich amine from Hydro treating units


H2S rich gas to SRU

Lean amine to units



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11. Sour water stripper unit (SWS)strips out ammonia and hydrogen sulphide

from contaminated process water ( especially from Hydro-processing units)

before draining to ETP.

Process : Sour water rich in ammonia and H2S stripper -> Ammonia & H2S

vapours to SRU and stripper sour water to Units and Effluent treatment

plant.

Feed

Sour water From uits


Ammonia and H2S rich gas to SRU

Stripped sour water to Units and ETP



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12. Other untis

KTUKero treater unit for Aviation turbine fuel (ATF) production from

Kerosene.

FCC Light naphtha treating unitfor removal of mercaptan suphur

FCC LPG treater - for removal of mercaptan suphur

Sulphuric acid regeneration unit (SARU)for regeneration of spent acid

from Alkylation unit. ETPeffluent treatment unit

Blending station for MS blending

Incinerator for burning sold waste.

Intermediate stream storage tanks Hydrogen bullet

Flushing oil system

FINISHED PRODUCTS


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FINISHED PRODUCTS


Liquefied petroleum gas : propane or butane, is a flammable mixture of hydrocarbon

gases used as a fuel in heating appliances and vehicles.

LPG SPECIFICATIONS (BIS:4576-1999)

LPG DOMESTIC - BULK (ASTM/IP/IS1448)

S no Test method Method Specification

1 Copper Corrosion @38 C 1 Hr D 1838 Not Worse than1

2 Free Water Content VISUAL NOT PRESENT

3 Hydrogen Sulphide D 2420 Passes the TEST

4 Odour P 75 Min. 2.0

5 Total Volatile Sulphur D 2784 Max. 150.0 ppm

6 Volatility (Evapor.Temp 95%V @ 760 mmHg) D 1837 Max. 2.00 CEL

7 Vapour Pressure @40 C D 1267 Max. 1050.0 kPa

FINISHED PRODUCTS


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FINISHED PRODUCTS


Motor Spirit (also known as petrol):is a petroleum-derived liquid that is used primarily

as a fuel in internal combustion engines.

BS-IV MS specification (ASTM/IP/IS1448)S no Test method Specification Method

1 Density @ 15C 720.0 .. 775.0 kg/m3 P 16

2 Recovery upto 70C ( E 70 ) 10.0 .. 45.0 vol% P 18

3 Recovery upto 100C ( E 100 ) 40.0 .. 70.0 vol% P 18

4 Recovery upto 150C ( E 150 ) Min. 75.0 vol% P 18

5 Final Boiling Point ( FBP ) . C Max. 210.0 C P 18

6 Residue Max. 2 vol% P 18

7 Research Octane Number ( RON ) Min. 91.0 P 278 Motor Octane Number ( MON ) Min. 81.0 P 26

9 Existent Gum Content ( Solvent washed ) Max. 40.0 mg/dcl P 29

10 Oxidation Stability, minutes Min. 360

11 Sulphur Total Max. 50 mg/kg D 2622

12 Lead Content ( as Pb ) Max. 0.005 g/l

13 Reid Vapour Pressure ( RVP )@38C Max. 60 kPa P 39

14 Vapour Lock Index ( VLI CAL Max. 95015 Benzene Content Max. 1.0 vol%

16 Cu Strip Corrosion (3hrs @/50P 15 degC) Class 1

17 Olefin Content Max. 21.00 vol% P 23

18 Aromatics Content Max. 35.0 vol% P 23

FINISHED PRODUCTS


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FINISHED PRODUCTS


Kerosene: Kerosene is a combustible hydrocarbon liquid. Kerosene lamps are widely

used for lighting in rural areas.

KEROSENE SPECIFICATIONS(IS:1459-1974)

SUPERIOR KEROSENE - (PDS) (ASTM/IP/IS1448)

S no Test method Specification Method

1 Acidity Inorganic in mg.KOH/gm P 2 Max. 0.00

2 Bloom on Glass Chimney P 5 Not Darker than Grey

3 Copper Cor @50C for 3hrs P 15 Not Worse than1

4 Burn Test Char Value P 5 Max. 20.0 mg/kg

5 Colour Saybolt P 14 Min. 10.0

6 Density at 15 C P 16 kg/m3

7 Recovery @ 200 C P 18 (T) 20.00 vol%

8 Dist- FBP P 18 Max. 300.0 CEL

9 Flash Point P 20 Min. 35.0 CEL

10 Smoke Point P 31 Min. 18.00 mm

11 Sulphur Content Total P 34 Max. 0.2500 mass%

FINISHED PRODUCTS


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FINISHED PRODUCTS


HSD (high speed Diesel ) : Liquid fuel used in diesel engines (IS:1460-2010)

HSD - BS IV specification (ASTM/IP/IS1448)

S no Test method Specification Method

1 Acidity, inorganic in mg KOH/gm P 2 Max. 0.002 Acidity, Total, mg of KOH/g P 2 ---

3 Ash Content Max. % mass P 4 Max. 0.0100 mass%

4 RCR(10% Residue) P 8 Max. 0.30 mass%

5 Cetane number ( CN ) P 9 Min. 51.0

6 Cetane Index ( CI ) D 4737 Min. 46.0

7 Pour Point, Summer C P 10 Max. 15 C

8 Dist. % v/v, Rec @ 360C P 18 Min. 95.09 Flash point: ( Abel ) C P 20 Min. 35.0 C

10 Kinematic Viscosity @ 40C P 25 2.000 .. 4.500 cSt

11 Density @ 15C P 16 820.0 .. 845.0 kg/m3

12 Total Sulphur D 2622 Max. 50 mg/kg

13 Water Content Max. 200 mg/kg

14 Cold Filter Plugging point (Summer) P 110 Max. 18 C

15 Total Contaminations EN 12662 Max. 24.0 mg/kg16 Oxidation stability D 2274 Max. 25 g/m3

17 Polycyclic Aromatic Hydrocarbon( PAH ) IP 391 Max. 11.0 mass%

18 Lubricity, corrected wear scar diameter ISO12156 Max. 460 m

19 Cu Strip Corrosion (3hrs @/50P 15 DegC Class 1

PETROLEUM PROPERTIES


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Reid vapor pressure (RVP) is the absolute pressure exerted by a mixture at

37.7C (100 oF)

Applicable to LPG, Gasoline

Pour point of a petroleum fraction is the lowest temperature at which the oil will

pour or flow when it is cooled without stirring under standard cooling conditions.

Applicable to ATF , Diesel and fuel oils

Flash point for a hydrocarbon or a fuel is the minimum temperature at which

vapor pressure of the hydrocarbon is sufficient to produce the vapor needed for

spontaneous ignition of the hydrocarbon with the air with the presence of an

external source, i.e., spark or flame.

Flash point is an important parameter for safety considerations, especially duringstorage and transportation of volatile petroleum products. The surrounding

temperature around a storage tank should always be less than the flash point of the

fuel to avoid possibility of ignition.

Applicable to ATF , Diesel and Fuel oil.



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Fire point : Flash point should not be mistaken withfire point, which is definedas the minimum temperature at which the hydrocarbon will continue to burn for atleast 5 seconds after being ignited by a flame.

Auto-ignition temperatureis the minimum temperature at which hydrocarbonvapor when mixed with air can spontaneously ignite without the presence of anyexternal source. Values of auto-ignition temperature are generally higher than flashpoint.

Flammability range :

To have a combustion, three elements are required: fuel (hydrocarbon vapor),oxygen (i.e., air), and a spark to initiate the combustion.

One important parameter to have a good combustion is the ratio of air tohydrocarbon fuel.

The combustion does not occur if there is too much air (little fuel) or too little air(too much fuel).

This suggests that combustion occurs when hydrocarbon concentration in the airis within a certain range.

This range is calledflammability range and is usually expressed in terms of lowerand upper volume percent in the mixture of hydrocarbon vapor and air.



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Octane number is a parameter defined to characterize antiknock

characteristic of a fuel (gasoline and jet fuel) for spark ignition engines.

Octane number is a measure of fuel's ability to resist auto-ignition duringcompression and prior to ignition. Higher octane number fuels have better

engine performance.

The octane number of a fuel is measured based on two reference

hydrocarbons of n-heptane with an assigned octane number of zero andisooctane (2,2,4-trimethylpentane)with assigned octane number of 100.



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Motor octane number (MON)andresearch octane number (RON) :

are two methods of measuring octane number of a fuel in the

laboratory.

TheMONis indicative of high-speed performance (900 rpm) and is

measured under heavy road conditions.

The RON is indicative of normal road performance under low enginespeed (600 rpm) city driving conditions.

Isoparaffins and aromatics have high octane numbers while n-paraffins

and olefins have low octane numbers.

In some countries average of the RON and the MON is called Pump

Octane Number(PON) or Anti-Knock Index (AKI)

PETROLEUM PROPERTIES (octane number)


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PETROLEUM PROPERTIES (octane number)


Generally there are three kinds of gasoline: regular, intermediate, and

premium with PON of 87, 90, and 93, respectively.

Improving the octane number of fuel would result in reducing power loss ofthe engine, improving fuel economy, and a reduction in environmental

pollutants and engine damage.

There are a number of additives that can improve octane number of

gasoline.

These additives are tetra-ethyl lead (TEL)not in use, alcohols, and ethers.



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Cetane number (CN) :

For diesel engines, the fuel must have a characteristic that favors auto-

ignition.

The ignition delay period can be evaluated by the fuel characterization

factor called cetane number (CN).

The shorter the ignition delay period the higher CN value.

The cetane number is defined as:

CN= vol% n-cetane+ 0.15(vo1% HMN)

Where n-cetane (n-C16

H34

) has a CN of 100, and heptamethylnonane

(HMN) has a CN of 15.

PETROLEUM PROPERTIES (cetane number)


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PETROLEUM PROPERTIES (cetane number)


Higher Cetane number fuels reduce combustion noise and permit improved

control of combustion resulting in increased engine efficiency and power

output.

Higher Cetane number fuels tend to result in easier starting and faster

warm-up in cold weather and can cause reduction in air pollution.

Cetane number of diesel fuels can be improved by adding additives such as2-ethyl-hexyl nitrate or other types of alkyl nitrates.



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Smoke Point (SP)

is a maximum flame height at which a fuel can be burned in a standard

wick-fed lamp without smoking.

It is expressed in millimeters and a high smoke point indicates a fuel with

low smoke-producing tendency.

Smoke point is a characteristic of aviation turbine fuels and kerosenes and

indicates the tendency of a fuel to burn with a smoky flame.

Higher amount of aromatics in a fuel causes a smoky characteristic for the

flame and energy loss due to thermal radiation.



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Carbon residue (CR):

When a petroleum fraction is vaporized in the absence of air at atmospheric

pressure, the nonvolatile compounds have a carbonaceous residue known ascarbon residue (CR).

Therefore, heavier fractions with more aromatic contents have higher carbon

residues while volatile and light fractions such as naphthas and gasolines have

no carbon residues.

There are three different test methods to measure carbon residues,

Ramsbottom (ASTM D 524), the Conradson (ASTM D 189) and microcarbon

(ASTM D 4530). In most cases carbon residues are reported in wt%.

RECAP


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RECAP


What is the primary process in refining?

What are all called secondary process? Why secondary processing?

What are straight run products? What are all finished products from refinery?

Properties of Kerosene?

Properties of Diesel?

Properties of Gasoline?

QUERIES


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QUERIES



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Documents

Fundamentals of Refining Products and properties