3 Furnace Furnace Revamps Revamps Revamps in in Low Low Budget Times -- Technip

8/13/2019 3 Furnace Furnace Revamps Revamps Revamps in in Low Low Budget Times -- Technip

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Copyright Technip. The presentation herein is intended for presentation purposes; any unauthorized use, review, transmission, dissemination, distribution or copying is stricktly prohibited

FurnaceFurnaceFurnaceFurnace RevampsRevampsRevampsRevamps ininininLowLowLowLow Budget TimesBudget TimesBudget TimesBudget Times

Koos OverwaterTechnip Benelux, The Netherlands

Richard KrumpenLyondellBasell Industries, Germany

Prepared for Presentation at the 2010 AIChE Spring Meeting,

San Antonio, Texas, March 21-25, 2010


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2Copyright Technip. The presentation herein is intended for presentation purposes; any unauthorized use, review, transmission,

dissemination, distribution or copying is stricktly prohibited

I. CRACKING FUNDAMENTALS

III. LYONDELLBASELL OM4 RECOILING

II. FURNACE MODERNIZATION - APPROACH


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I. CRACKING FUNDAMENTALS


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Characteristics of Olefins Production

Strongly endothermic process

Absorbed duty: Q ~1.6 Gcal / tonne of feed

For 1.350 kta cracker: fired heat ~ 840 MW

Feed Products

Q


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Radiant Section

Convection Section

~

~Hydrocarbon

Feed

Boiler Feed Water

Dilution Steam

HP Steam

Desuper-heater

Cracked Gas to

Separation Section

Transferline Exchanger

BFW

Radiant efficiency: 40 42%

Overall efficiency: 92 95 %

850 oC1250 oC

120 oC

620 oC

380 oC

520 oC

Steam Drum

Cracking Furnace


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Feedstock Selection and Ethylene Yields

1822981Benzene

2161291417324Other (fuel)

2117440Raffinate-1

1814160Butadiene

605245350Propylene

100100100100100Ethylene

433334300226125Feed

GasoilNaphthaC4-LPGC3-LPGEthane

(Feed and Products in tons per 100 ton of ethylene product)


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Mixed

Products

Quench

Drier

Fuel Oil

Hydrogen

Compressor andChilling

Steam

Quench Methane

AcetyleneConverter

Ethane

Ethylene

PropanePropylene

NAPDConverter

MixedButanes

Gasoline

CrackingFurnaces

Ethane

Naphtha

Acid Gas

PrimaryFractionator

Feeds

Material Movements

Utilities

Olefins Complex


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Cracking is:

non-catalytic governed by reaction kinetics

intrinsically non-selective

Hence:

looking primitive and unsophisticated, but requires advanced engineering modelling:

SPYRO

Cracking Technology


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SPYRORigorous Simulation of Steam CrackingProcess

CRACKINGCRACKING

SECTIONSECTION

HYDROGENHYDROGEN

METHANEMETHANE

::

ETHYLENEETHYLENEPROPYLENEPROPYLENE

::

GASOLINEGASOLINE

FUEL OILFUEL OIL

SPYROSPYRO == PREDICTION OF EFFLUENT SLATE ASPREDICTION OF EFFLUENT SLATE AS

FUNCTION OF:FUNCTION OF:

1. FEED SPECIFICATIONS1. FEED SPECIFICATIONS

2. OPERATING CONDITIONS2. OPERATING CONDITIONS

3. COIL GEOMETRY3. COIL GEOMETRY


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SPYROModel

THERMODYNAMICTHERMODYNAMICCONSISTENCY WITHCONSISTENCY WITH

REVERSE REACTIONSREVERSE REACTIONS

THERMOCHEMICALTHERMOCHEMICALKINETICKINETIC

THEORIESTHEORIES

LITERATURELITERATURE

DATADATA

COMPLETENESSCOMPLETENESS

AND SIMPLIFICATIONAND SIMPLIFICATION

LEVELLEVEL

KINETICKINETIC

SCHEMESCHEME

ANALOGIESANALOGIES

BETWEEN SIMILARBETWEEN SIMILAR

REACTIONSREACTIONS

NUMERICALNUMERICAL

METHODSMETHODSREACTORREACTOR

MODELMODEL

EXPERIMENTALEXPERIMENTAL

DATADATARESULTSRESULTS

TUNINGTUNING

FACTORSFACTORS


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128 Components + 20 radicals

Hydrocarbon components C1 - C42 Groups

Paraffins, Normal- & Iso-Naphtenics, mono-, di-, poly

Aromatics, mono, di-, poly-Olefins, di-Olefins

Real components Pseudo (lumped) components

H2O, CO, CO2, H2

SPYROComponent Library


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SPYROenables optimization of :

Coil selection

Coil sizing

against :

Yields

Runlengths

Feedstock flexibility

Operating cost

Investment cost

CONVENTIONAL (MK) GK1 OR GK2 GK3

GK4 GK5 GK6

SMK

SPYRO : Tool Kit for Cracking Furnace Design


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Radiant Section

Convection Section

~

~Hydrocarbon

Feed

Boiler Feed Water

Dilution Steam

HP Steam

Desuper-heater

Cracked Gas to

Separation Section

Transferline Exchanger

BFW

Radiant efficiency: 40 42%

Overall efficiency: 92 95 %

850 oC1250 oC

120 oC

620 oC

380 oC

520 oC

Steam Drum

SPYRO Simulation Suite covers complete furnace

SPYROFIREBOX

CONVECTES


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II. FURNACE MODERNIZATION - APPROACH


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Furnace Modernization Approach (Phases)

C2=

FeasibilityPhase

Proposal Phase

Project Execution

Modernized Furnace

Increased Production / Reliability

C2=


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Furnace Modernization Approach

Feasibility

Phase

Base Case

Revamp Cases

Validation


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Feasibility

Phase

Base Case

Revamp Cases

Validation

OPERATING DATA

EXISTING DESIGN

PLANT ISSUES

MAINTENANCE

CONTROL


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Feasibility

Phase

VALIDATED MODEL

DEFINITION OF BASE CASE

REFERENCE CASE

Base Case

Revamp Cases

Validation


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TARGETS

TECHNIP COIL DESIGN

COMPARISON

INTERACTION

CHOICE

COMPLETE ADEQUACY CHECK

TECHNIP COIL DESIGN

Feasibility

Phase

Base Case

Revamp Cases

Validation



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Technip Radiant Coil Types - Overview

GK1 OR GK2GK1 OR GK2 GK3GK3 GK4GK4 GK5GK5

CONVENTIONAL (MK)CONVENTIONAL (MK)

GK6GK6

SMKSMK


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Technip Radiant Coil Types GK6 (Liquid Cracking)


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SPYROTM

Technip Radiant Coil Type - Selection

CAPACITYCAPACITY

FEEDSTOCKS FIREBOX DIMENSION

HEAT FLUX

NO. OF NEW COILSTYPE OF COILS

RUNLENGTHRUNLENGTH

COIL SURFACE AREA

FIRED HEAT


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TARGETS

TECHNIP COIL DESIGN

COMPARISON

INTERACTION

CHOICE


Feasibility

Phase

Base Case

Revamp Cases

Validation



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Design Check List has been developed based on Experience of Furnace

Modernization

Check List addresses all furnace items; e.g.

Radiant Section,

Check Refractory

Check Burners (capacity, revamp options if required)

Check (partly) re-use of radiant inlet manifold

Convection Section

Check Capacity

Check Pressure drop (process side + flue gas side) Check Design Pressure, Design Temperature

Check Material adequacy incl. finning

Furnace Modernization Adequacy Check


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Steam System

Check Steam drum size

Check safety valve capacity

Check TLE ID Fan

Check Capacity

Check pressure drop

Check modification options if required

Lines + in-line Instrumentation

Lines around furnace: size, delta P, design temps.

Check size of Cracked gas valves, Check sizing of control valves and safety valves



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Check Control Philosophy

E.g. Pass balancing,

Check Foundation

For new loading after modernization

Check Structural Steel

For new design after modernization

Review Constructability

Review different scenarios for modernization

Enable short shutdown to minimize production stop of relevant furnace

Review Maintenance

For future maintenance work of modernized furnace design



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Capacity increase 0-15% 15-25% >25%New Radiant Coil X X X

Crossover piping X X X

Coil Support system X X X

Minor refractory work X X X

Critical Flow Venturi X X X

New Burners ** X X

New flue gas fan ** X X

New inlet cones to TLE X X

New TLE ** X

Convection Sectoin - Partial retubing X

Convection Sectoin - Extensive retubing X

Refractory change X

Piping Modifications - Partial X

Piping Modifications - Extensive X

Instrument Modification - Partial X

Instrument Modification - Extensive X

Scope of Modernization


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III. LYONDELLBASELL OM4 RECOILING


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Study Objectives

History: Original furnace design by Technip (KTI) in 1988 First recoiling design by Technip (KTI) in 1998 Second recoiling design by Technip in 2006

Operational parameters before second recoiling: Feedstock: Heavy liquid Feed Capacity: normal (average) 27 t/h (design: 32 t/h) Steam to Oil Ratio: X

Run length: 42 days, decreasing to less than 30 days over the years

Objectives:

Increase run length to > 30 days Investigate impact of lowering Steam to Oil ratio to STOR=X-10% Evaluate potential for furnace capacity increase


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Validation Case

Simulation by SPYROof existing operating data

Findings: Good match of operating data with simulation results (heat and material

balance matching) Firebox efficiency higher than original design (different flame/heat

release pattern) Coking rate adjusted to match run length data (effect of feedstock

quality)

Convection section performance reasonably good Air preheater shows some bypassing Approx. 5% of false air ingress in firebox


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Reference Case

Capacity: 31 t/h

Tuning parameters Firebox: heat release pattern as per validation case

Coking rate: as per validation case Convection Section: fouling coefficients as per validation case Air preheater efficiency: reduced as per validation case Excess air: as per validation case


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basebasekg/kgSeverity (Propylene/Ethylene ratio)

-3.6%basewt%Methane

+0.6%basewt%Ethylene

-5.5%basewt%Ethane

+0.7%basewt%Propylene

+3.0%baseMWFired Heat

+3.2%baset/hHP steam

+0.6%baset/hOnce through Ethylene Production+0.1%

9

28

X

31

ReferenceSTOR X

base

9

30

X-10%

31

ReferenceSTOR X10%

t/h

%

days

kg/kg

t/h

Ultimate Ethylene Production

STOR

Feedstock

Run length

Excess air

Case

Reference Case Effect of Steam to Oil Ratio


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Observations:

STOR X gives: slightly shorter run length

3.0% more firing 3.2% more HP Steam production

5.5% lower Recycle Gas production

STOR X-10% gives: more margin for capacity expansion

Reference Case Effect of Steam to Oil Ratio contd


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Radiant Coil Selection

Short Medium Kinetics

48 Coils in Two-lane Arrangement

Short Residence Time

High Selectivity

High Capacity

Simple, Robust Design

Coil Design Applying GK6 Technology

92 Furnaces Revamped with GK6Technology

SMK Type

Revamp


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-1.3%baset/hCombustion air

-1.0%baset/hFlue gases

+3.0%baset/hFuel gas

basebasekg/kgSeverity (Propylene/Ethylene ratio)

-4.3%basewt%Methane

+0.9%basewt%Ethylene

-7.5%basewt%Ethane

+0.8%basewt%Propylene

+3.0%baseMWFired Heat

+3.2%baset/hHP steam

+7.4%baset/hOnce through Ethylene Production

+6.6%

4.5

53

X-10%

33

Revamp -max. throughput

base

9

30

X-10%

31

Reference

t/h

%

days

kg/kg

t/h

Ultimate Ethylene Production

STOR

Feedstock

Run length

Excess air

Case

Revamp Case Performance overview


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Revamp Case Adequacy Checks of non-modifiedEquipment

Convection Section materials: Furnace efficiency increased

Lower fluegas temperatures (despite higher capacity)

Materials Convection Section OK

Flue Gas Fan: Lower amount of false air ingress Lower amount of combustion air (despite capacity increase) Lower amount of flue gases

Flue Gas Fan OK

Control Valves Feed: flow rate increased by 3%: OK

Dilution Steam: reduced by 10%: OK

Fuel gas: flow rate increased by 3%: OK


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Summary of Modifications

New Radiant Coil Replace existing coils with SMK coils in two-lane arrangement

New Radiant Coil Inlet Manifolds Replace existing manifolds, including new weld-on brackets

Existing rigid struts will be reused New Radiant Coil Support System

Replace existing counter weights with constant and variable load springs New Critical Flow Venturis

Replace existing venturis with new smaller venturis

New Shadow Box Cover Replace existing shadow box cover, including new protrusion seals

New Trough Replace existing bottom trough with a new larger one

No guide tubes required

R O ti l F db k


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Revamp Operational Feedback

Recoiled furnaces were started up smoothly Average furnace capacity increased from 27 t/h to 29 t/h Run length increased from 30 days to approx. 60 days Excess air could be reduced by approx. 5 %

Room for optimization: Market situation does not require operation at full capacity Critical Flow Venturuis at radiant coil inlets were sized for maximum flow

in combination with minimum supply pressures of feed and dilution

steam During turndown operation the originally anticipated STOR had to be

increased in order to keep the venturis under critical flow conditions Basis of Design may have to be modified in order to arrive at more

optimal venturi sizing for lower capacities

C l i R C t h t th t t f


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Conclusion: Revamp Concept has met the target ofincreased run length

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3 Furnace Furnace Revamps Revamps Revamps in in Low Low Budget Times -- Technip

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