clean fuel and petrochemicals

8/3/2019 Clean Fuel and Petrochemicals

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Clean FuelsandPetrochemical SynergiesLecture

Advanced Training CourseOn Clean Fuels

Indian Institute of Petroleum, IndiaDr. A. K. Gupta


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Returns on refining assets fallen to

inadequate levels due to

- Low growth for major refined products

- Poor upgrading margins

- Increased competition


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The drivers to these issues are:

Refinery/ Petrochemical Integration

Business diversification challenges (e.g.power generation, retail marketing)

Process technology developments Regulatory issues


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Growth Rate

Global Petroleum demand isexpected to average 2.2% duringnext 10 years

Global demand for majorpetrochemical will grow twice asfast.


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All the major petrochemical producing regions will be addingpetrochemical processing capacity to 2005

Petrochemical New Investment/additionMillion tons/ year

Ethylene 41.3

Benzene 10.5

Styrene 11.4

Poly-olefins+ 50.1

Para-xylene (PX) 11.1

Terephthalic Acid (PTA) 15.5

+ Polyolefins includes polypropylene, all grades of polyethylene(including LDPE- 29.2 million tons/year, LLDPE- 20.9 million

tons/year and HDPE


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WORLD ETHYLENE CAPACITY (MAY 1997)

1997 2000 % increase from 1997 to

2000North America 28,732 31,619 10

South America 3365 3935 16.9

West Europe 19,786 20,046 1.3

East Europe 7568 8058 6.5

Africa 1255 1555 23.9

Middle East 4846 6611 36.4

Asia 17812 22573 26.7

Australia 505 505 -

TOTAL 83,869 94,902 13.2

Source: Japan Petrochemical Industry Association, Tokyo, May 1997


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Propylene demand continues to exceedgrowth in production from steamcrackers

Projects to produce additionalpropylene from Refinery FCC units arebeing considered.


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ASIAN ETHYLENE PRODUCTION CAPACITY

1991 1997 2000* 2005/10*

Japan 6150 7114 7478 8554

South Korea 1232 3720 4380 4380China 2225 2338 4205 6723

Taiwan 745 960 1390 2365

East Asia Total 10,352 14,132 17,453 22,472

Singapore 400 960 1005 1760Thailand 230 1130 1130 1730

Malaysia - 530 1010 1600

Indonesia - 550 715 2265

Philippines - - - 500Asean Total 630 3170 3860 7855

India 510 510 1260 3950

Asia Grand Total 11,492 17,812 22,573 34,277

*Few of the above planned projects may not materialize or may be postponed, especiallythose in China and India.


9/70

World-scale steam cracker facilities

under construction cannot keep up withdemand

Result-

Refinery- based petrochemicals can

play a significant role in providing asecurity of supply to petrochemicalprocessors


10/70

INDIAN SCENE.

Post Administered Pricing Regime (APR)- Allow world market prices for refined products to be applied in India

As product prices change, the refineries will be faced with the need toimprove allocation of their capital and optimize crude oil selection

strategies. The products most in demand will be transportation fuels- diesel and

motor, meeting the stringent environmental regulations

Capacity increase and meeting specifications of fuels to meet stringent

regulations will be involve huge capital investments

Refinery profits will squeeze

Alternative options to improve profitability need to be looked into


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Profitability Cycles

Petrochemicals often exhibit cyclical profitability(6-7 years cycles)

Refining industry, cyclically differs in both timingand severity compared to petrochemicals

- Integration allows to temper the downturnsin petrochemicals by the more stable behaviorof refining cycle.


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Refinery/ Petrochemical integration also

brings other synergistic opportunities

- Energy optimization and cogeneration

- Recycling H2 from integratedpetrochemical complexes to refinery forincreased demand in hydroprocessingin reformulated products.


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Benefits of Integration

Advantage of Counter-seasonal trends in fuel/transportdemand vs. Petrochemical feedstock requirements.

Integrated economics often reflect lower refinery values forpetrochemical feed-stocks.

Many big products from the petrochemical operations can berecycled back to the refinery at higher value.

Competitive edge over stand-alone petrochemical complexes

Overall economics also improves from shared utilities,transportation, maintenance and administrative functions.

Finally, petrochemicals generally offer higher value, bettergrowth opportunities.


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Obstacles that can deter investments in

extending refinery operations into petro-

chemical operations include: High capital costs of new petrochemical units

Product/intermediate transfer costs betweenrefinery and petrochemical divisions

Refiners may see a higher rate of return in other

business such as retail marketing In contrast to refiners, many chemical industry

players prefer to make smaller acquisitions to fit

existing portfolios and minimize risks


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The future of petrochemical integrationinto the refinery cannot be characterizedin simple terms. It must first be

recognized that petrochemical industry isa large industry with many products and

more than 500 processes.


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If an existing refining facility does notalready produce a sizable quantity ofpetrochemical products, can it ever

hope to achieve an acceptable returnon petrochemical projects?


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Refiners produce a wide range of chemicalfeedstocks depending on crude type, refinerycomplexity, and other operating conditions.

Typically a limited number of refineryprocesses/ streams provide the primaryfeedstocks to support competitively sizedpetrochemical production.


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Contd..

PETROCHEMICALS FROM REFINERY STREAMS

Petrochemical Stream Refinery Stream Alternative

Refinery Use

Base PetrochemicalsEthylene Naphtha and LPG Fuel gas

Propylene Refinery propylene (FCC product) Alkylation

Benzene, toluene, xylenes(BTX)

Reformate Gasolineblending

Downstream Derivatives

Ethylbenzene Dilute ethylene (FCC and delayedcoker off-gases)

Fuel gas

Polypropylene Refinery propylene (FCC product) Alkylation

Isopropanol Refinery propylene (FCC product) Alkylation

Cumene Refinery propylene (FCC product) Alkylation


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Oligomers Refinery propylene

(FCC and delayed coker)

Alkylation

MEK Butylenes


Alkylation, MTBE Production

MTBE Butylenes


Alkylation, MTBE Production

Cyclohexane Reformate Gasoline blending

Ortho-Xylene Reformate Gasoline blending

Para-Xylene Reformate Gasoline blending

Normal paraffins Kerosene Refinery product

Naphthalene FCC light cycle oil Diesel blend-stock after

hydro-treating


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Contd.

REFINERY-GENERATED FEED-STOCKS AND THEIR COMMONAND POTENTIAL USAGE

Feed-Stock Derivatives

LPG (Propane,Butane)

Feedstock for:

Ethylene, Propylene, Butylenes by steamcracking/dehydrogenation:

Aromatics by aromizing

Acid, aldehydes & ketones through oxidn.

Naphtha Light and heavy for olefins and aromatics production,depending upon the composition (steamcracking/Reforming)

Light naphtha to C5-stream

Hydrogenation of benzene rich fraction (69-90C) forcyclohexane/ cyclohexene, which is feed stock forfibre industry.

Kerosene n-paraffins for LAB, LAS etc.

specialty chemicals, plasticizers and solvent


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Contd.

Gas Oil Feedstock for steam cracking to produce olefins(commonly used in china).

Gas oil from thermal conversion process- alpha

olefins for AOS.FCC off gases Propylene, isopropanol, cumene, oligomers,

polypropylene, acrylic acid.

Butylenes- MEK, MTBE, oligomers, purebutene-1, alkyl phenols and additives, acrolein,

MMA acrylic acid.

High octane, benzene free gasoline blendingcomponent by alkylating benzene rich naphthawith FCC- off gases and isobutene.

DCC

Olefins

Kerosene fromthermal process(visbreaking, coking)

n-paraffins, alpha olefins,

aromatics naphthalene


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Reformate BTX

C9+ aromatics from reformate and their

conversion,

Residues sludge,coke etc.

Power (IGCC), steam, H2, Syn gas-chemicals,High cetane, zero sulfur diesel, specialty linearwaxes, olefins, alcohols etc.

Petroleum Coke Use based on acetylene chemistry


23/70

Levels of Refining and Petrochemical

Integrations

Forward Integration

Utilization of refinery manufactured products aspetrochemical feedstock rather than gasolineblending component.

Backward Integration Disposal of petrochemical by-products to

refinery applications, namely gasoline blending.


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Site-wide and System-wide Integration

Side-wide integration

Petrochemical and refining operations areintegrated on one site.

System-wide integration

Products are traded between severalindependent refinery and petrochemicalsites.


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Figure 1: process Flow diagram of an integrated refinery & Petrochemicals plant


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Basic Petrochemical Plans

1. Steam cracker or olefins plant.

2. Aromatic Plant

Both units obtain feedstocks from refining section.

LPG, light or full range naphtha and unconvertedoil for steam cracker.

Reformate for aromatics.

Alternatively these feedstocks are also availablefrom the market.


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Alternatives for light naphtha

1. Feedstock for steam cracker

2. Feed stock for isomerisation unit


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Alternatives for Reformate

1. Feedstock for Aromatics

2. Gasoline Blending Component


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Auto Oil Programmes will

Affect

Recipe for gasoline blending

Choice for feedstocks for steam cracking

and aromatics unit.


30/70

Both steam crackers and aromatics

units

Produce by-products in addition to C2H4,C3H6 or aromatics.

Some of these by-products return to therefinery as gasoline blend stocks calledChemical Returns.


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Changing fuel specifications will have animpact on the interfaces or synergies of

refining and petrochemical operations.


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Chemical returns from steam cracker

include : pyrolysis gasoline, followingbenzene extraction

Pygas split - Light & heavy

Chemical returns from aromatic unit consistsof C9 or C8 (xylenes) aromatics.


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The fuel regulations being enacted will

change the blending values andopportunities for chemical returns as well asthe availability of light naphtha as cracker

feed.

This effect will be increased by the fact that

gasoline demand is expected to increase atlow pace than demand for C2H4 and C3H6.


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Gasoline Specification due to AOP

Before AOP AOP 200 AOP 2005

Sulphur ppm Max. 500 Max. 150 Max. 50

Benzene %v/v Max. 5 Max. 1 Max. 1

Aromatics %v/v - Max. 42 Max. 35

Olefins %v/v - Max. 18 Max. 18


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Changing Gasoline Specifications

Sulfur

Benzene

Aromatics

Olefins


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Impact of Changing Gasoline

Specifications

The changing Gasoline specifications will influence:

Quantity and quality of feed stocks available forpetrochemical production.

Gasoline blending strategies.


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The reduction in aromatics content of

gasoline will have major impact on refining-petrochemical synergies.

All other parameters also needs to beconsidered; these will limit the blendingreturns into gasoline pool and restrict the

availability of light naphtha as petrochemicalfeedstock.


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There are four general refinery types

Hydroskimmer, refineries consisting only of topping andreforming.

FCC-type, refineries with FCC plant for VGO or rasid

cracking without additional hydrogen.

Hydrocracker type, refineries including a hydrocracker plantfor VGO cracking with hydrogen addition.

Complex or FCC/Hydrocracker type, are refineries withboth types of cracking units.


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Refinery types and aromatics content in gasoline

HydroskimmerTopping and Reforming units only

About 51% aromatics content in gasoline; corresponding to 77% reformate

FCC type

Hydroskimming and additional FCC for VGO cracking without hydrogen additionless than 35% aromatics content in gasoline; corresponding to about 38% reformate

Hydrocracker type

Hydroskimming and additional Hydrocracker for VGO cracking with hydrogen

addition about 54% aromatics content in gasoline; corresponding to 83% reformate.Complex or FCC/HC type

Hydroskimming plus FCC and HC units

About 45% aromatics content in gasoline; corresponding to 60% reformate

Q li i f i l li bl di


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Qualities of typical gasoline blending components

Blending

Component

Benzene

Vol%

Sulphur

ppm

Olefins

vol%

Aromatics

Vol%

RON/MON

Reformate 1,0-10 1 0 60-75 99/98

FCC gasoline 0,7-1,0 100-2000 30-40 5-45 91-96 / 78-84

-light cut 0,9-1,5 15-300 20-55 1-2 98-96/80-82

-heavy cut 0,1-1,1 350-3500 2-14 40-60 91-96/78-84

Isomerisate 0 0 0 0 87-92/84-90

Alkylate 0 0 1 0 95/93

MTBE 0 0 1 0 111/96

Pyrolysisgasoline

0-6 0-600 25-35 75-88 98/84

- light cut 0-6 0-50 55 5 96/80

-heavy cut


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Blend Stock Qualities

Pyrolysis Gasoline quality parameters are similar toFCC gasoline.

PG has favourable RON and acceptable MON.

Sulfur, olefins and aromatics content of PG exceedfuture gasoline specs.

Light PG is low in aromatics but olefins content isextremely high; MON is insufficient.

Reverse is true for heavy PG high aromatics low

olefins.

Pyrolysis Gasoline (PG)


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C-9 Aromatics

C-9 aromatics are excellent gasoline blendstock

High aromaticity. Negligible olefin content.

Octane comparable to reformate

High aromaticity will limit the future usageas blends.


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Reformate has added advantages over C-9

aromatics

Reformate has lower aromatic content.

Naphtha reforming generates H2 as by-product.

Distillation range of reformate favourable to gasolineblending.

C9-aromatics production can be reduced by cuttingreformer feed TBP (140C max.)

One option to limit aromatics in gasoline is dilution

with MTBE, alkylate, isomerisate etc.


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Due to high aromatics and olefinscontent chemical returns used asgasoline blending components is likely to

provide less revenues


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At 42% aromatics level:

As gasoline blends Hydroskimmer andHydrocracker refineries are limited by aromatics

specifications.

Sulfur is constraint for FCC and complex

refineries

FCC gasoline blending is not limited byaromatics content.


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At 35% aromatic limitation:

FCC refineries will not be able to take aromaticssurplus-refineries or C9-aromatics from

petrochemical operations.

Solution lies in dilution

- isomerisate

- Extraction of aromatics


47/70

The reasons for increasing the isomeratecapacity may be summarized as follows:

Easy availability of light naphtha,

Increasing gasoline demand,

Lead phase-out,

Regular grade versus Euro Super and Super 98,

Benzene limitation,

Aromatics limitation,

Sulphur limitation, as the octane losses of FCClight gasoline due to deep hydrogenation have tobe compensated.


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Steam Cracker feed stock

Increasing use of isomerisation will affect steamcracker feed supply and quality.

Unconverted oil (UCO) form hydrocrackerproduces less ethylene than high quality naphtha.

Ethane and LPG are other alternatives.

Condensate may emerge as real alternative.


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Naphtha volume and quality will

change due to:

Increasing light naphtha/isomerate

requirements at refinery site for aromaticsdilution.

And because of growing olefins demand whilefuel requirements are stable or relaxed.

Ch i hth lit


50/70

Changing naphtha quality:

will cause lower ethylene and propylene yields at the same

throughput, while pygas output will increase.

changing naphtha quality will also cause higher aromaticscontent in pygas and larger heavy pygas volumes.

due to more stringent gasoline specifications especially withrespect to aromatics.

there will be lower blending values of pygas and C9-

aromatics.

and a limiting of light pygas blending into gasoline due tohigh olefin content.


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Synergies between FCC and olefin

production

Catalytic Cracking can be a supplementarysource for olefins.


52/70

Generally FCC is designed to produce gasoline anddiesel. (Large pore zeolites)

Medium pore zeolites over crack gasoline to propyleneand butylenes

- Pentasil family of molecular sieves are

used for this application- ZSM-5 structure most successful

- Product gases contain 5-7 wt% propylene

OLEFINS FROM FCC

DEEP CATALYTIC CRACKING (DCC)


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DEEP CATALYTIC CRACKING (DCC)

DCC is an extension of FCC process to producemore propylene and butylenes.

Propylene yields of 18-20% can be obtained

Modes of operation

- maximization of propylene

- maximization of iso-olefins Overall scheme is very similar to that of a

conventional FCC


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Typical Operation Conditions

DCC FCC Steam

Cracking

Temperature C 1020-1100 920-1020 1400-1600

Cat./oil ratio 8-15 4-10 --

Dispersionsteam wt%

10-30 0-2 30-80

Pressure, psig 15-30 15-30 atm

Petro FCC


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Petro FCC

Targets producing petrochemical feedstocks rather than fuel

products

Based on new catalyst (Rx-Cat) to improve yield of propyleneand aromatics.

- Lower HC partial pressure

- Slightly higher reactor outlet temperature

- Improved spent catalyst stripping- Nearly eliminating post-riser, non-selective back-mixed

cracking

- High catalyst flux rates

Yi ld P tt


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Yield Patterns

Component, wt% Traditional FCC Petro FCC

H2S, H2, C1 & C2Ethylene

Propane

Propylene

Butanes

Butylenes

Naphtha

DistillateFuel Oil

Coke

2.0

1.0

1.8

4.7

4.5

6.5

53.5

14.07.0

5.0

3.0

6.0

2.0

22.0

5.0

14.0

28.0

9.55.0

5.5


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Catalytic Pyrolysis Process (CPP)

It is a hybrid DCC- steam crackingsystem.

Operated under more severe conditionsthan DCC

Combined yield of C2-C4 is very high It is a petrochemical process designed tomake a range of olefins and aromatics.

CATALYTIC PYROLYSIS PROCESS TYPICAL


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CATALYTIC PYROLYSIS PROCESS- TYPICAL

PRODUCT DISTRIBUTION

Product yield, wt%

Ethylene 22.78

Propylene & butylene 29.62C5+ naphtha 14.93

LCO 3.72

HCO 4.56

Coke 8.67

Conversion, wt% 91.72

(Feed: atm residue)

RESID PROCESSING


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RESID PROCESSING

Currently the primary goal of an Indian refinery is: To upgrade as much crude as possible into saleable fuel products.

Maximizing overall profitability.

Current options:- Carbon rejection (coking, deasphalting)

Hydrogen addition (resid hydroprocessing) (needs additional

hydrogen)

These options leave behind undesired hydrogen-deficient materialrich in carbon, sulfur, metals etc.


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OTHER OPTIONS..

The ability to convert this unmarketablematerial to produce electricity, cleanlighter fuels and petrochemicals permitsthe refinery to increase its profitability


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The refiner can choose among three electric-

power-generation methods:

Circulating-fluidized beds (CFB)

Boilers with flue gas desulfurization (FGD) Integrated gasification combined cycle (IGCC)


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Primary factors affecting the selection for

power generation need balancing

- Environmental issues

- Efficiency

- Economics while preserving strategic

options for future investments.


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RESIDUE CONVERSION

GASIFICATION

Gasification

Power, hydrogen

Syn gas petro-chemicals

Offers an alternative to handle high sulfur and metalcontaining residues in a refinery with value addition

Alternative economically attractive option for many of the

problems associated with changing scenario in thepetroleum refining industry

Great advantage in co-generation and petro-chemicals viasyn gas

COMPARISON OF ELECTRICAL GENERATION OPTIONS


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COMPARISON OF ELECTRICAL GENERATION OPTIONS

CFB FGD IGCC

Sulfur-removalexperience

95% 95% +98%

Merchantable sulfur No No Yes

Oxygen/ nitrogenbyproduct No No Yes

Hydrogen

byproduct

Cost. $/kw

No

900

No

700

Yes

800-1,000

COMPARISON OF TYPICAL EMISSIONS, LB/MW-HR @


65/70

, @

100% CAPACITYNatural gas

combinedcycle

Coke gasif.

Combined cycle

Coke

circulatingfluid bed

Coke

boiler FGD& SCR*

SO2 0.0 0.5 3.7 3.6

NOx 0.3 0.4 0.9 1,5

CO 0.2 0.3 1.5 NAVOC 0.02 0.07 0.08 NA

Particulates 0.05 0.07 0.2 0.2

CO2 820 1,930 2,170 2,120

Solid waste 0.00 9.1 350 190

*Fuel gas desulfurization and selective catalytic reduction.The solid wastes from acoke gasifier contain only the feed metals plus some carbon.

PETRO CHEMICALS FROM REFINERY


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PETRO-CHEMICALS FROM REFINERY

COKE

Valuable material for producing petro-chemicals

Excellent source for high purity acetylenewhich is a useful starting material for host of

petro-chemicals such as acrylonitrile,vinylchloride, acrylic monomer etc.

PETRO CHEMICALS FROM REFINERY COKE


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PETRO-CHEMICALS FROM REFINERY COKE

CRUDEOIL

REFINERY GASOLINE, DISTILLATE, ETC

REFINERY

CALCIUM

CARBIDE

PLANT

PETROCHEMICAL

PLANT

ELECTRIC

UTILITY

RES. & COMM. POWER

TO COMMUNITY

COKEACETYLENE

OR

CARBIDE

PETROCHEMICALPRODUCTS

POWER

CaCN 2HCNMgACRYLONITRILEVINYL CHLORIDE PLASTICSACRYLIC MONOMERACETYLENE BLACKCHLORINATED SOLVENTSACETALDEHYDE

ACETIC ACIDACETIC ANHYDRIDEACETYLENE CHEMICALSFROM REPPE CHEMISTRY

Figure -12: Fuel power relationship between refinery, utility plant, carbide plant, and petrochemical plant


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Impact of Diesel Quality

If only further sulfur reduction isinvolved, there is likely no impact onpetro-chemicals.

Summary:


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Summary:

More stringent gasoline specifications will change refiningand petrochemical synergies, as they will have an impacton refinery/ petrochemical interfaces.

Future diesel specifications are likely to have very little orno impact on refining and petrochemical integration.

Isomerization of light naphtha likely to play an importantrole.

Pyrolysis gasoline upgradation need to be relooked.

FCC, DCC and CPP will have major impact onpetrochemical refinery integration


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clean fuel and petrochemicals

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