Symmetry Process Software Platform Steam Cracking Furnaces

Process Software Platform Steam Cracking Furnaces

Tailored workspaces—optimized facility Symmetry

Intelligent Simulation and Optimization of Steam Cracking FurnacesSymmetry*, a process software platform, is a comprehensive simulator that empowers all aspects of your models from reservoir to product distribution.

The Symmetry platform’s steam cracking furnaces are thermal cracking models that include rigorous kinetic reactions where a wide range of feeds—from light hydrocarbons, such as ethane, all the way to vacuum residues—are heated. The resulting changes in composition due to cracking and other reactions are tracked at every point of the coil(s), all while calculating coke growth rate simultaneously. Furnace simulation enables the optimization of ethylene production in the case of lighter feeds and rigorously predicts the effect of feed compositions and process conditions on coke formation and therefore service time runs.


FeedstocksSelection

YieldPrediction

TotalOptimization

Coke GrowthPrediction

FriendlyInterface

■ Paraffins, isoparaffins, olefins, naphthenes, and aromatics (PIONA) molecular structure environment

■ Feedstock selection and blending optimization ■ Easy matching of plant operating data ■ Seamless integration of cracking furnaces and product separation ■ Geometry input for radiant box and convection sections ■ User-friendly Excel interface ■ Rigorous coke growth and service time prediction ■ Multiple cracking furnace scheduling

User-Friendly InterfaceUsers can easily link the Symmetry platform to Excel using our built-in Excel Unit Operation which eliminates the need to write code.

Additionally, the Symmetry platform includes a Component Object Model (COM) link layer which provides a customizable interface that enables you to interact directly with the process simulator without the GUI. This can be used to link the Symmetry platform with any COM-compliant application such as Excel, Visual Basic, C++, Python, and many others.

PIONA Molecular Structure TechnologyHydrocarbon fluids are complex mixtures of many chemical species. This poses a challenge for characterization using conventional methods, where hypothetical components need to be created for each sample, blends, and product.

The Symmetry platform’s PIONA molecular-structure-characterization approach represents hydrocarbon fluids in terms of chemical families and carbon number. We can rigorously capture the essential chemistry of the fluids and blends to calculate chemical and physical properties. This approach can also mechanistically predict kinetic rates using only a limited number of components. This enables you to perform highly accurate feed blending studies, including reaction kinetics prediction.

8 Cur Row = 170 Tube Coil Inlet = 0.02 mm Case Name = SteamCrackingFurnace-C2-C3.vsymRow = 171 Tube Pass 2 = 7.64 mm

LastRow = 500 Tube Pass 4 = 7.98 mm Number of service runs = 8Tube Coil Outlet = 13.61 mm Service Run Profit = 37561

Max Coil DP = 150.0 kPa *Unit conversion:Max Tube T = 1093.3 C y = BIAS + x*MULT (from data to model) Time Step = 6

Run Length 39COKE COKE COKE COKE COKE COKE COKE COKE MAX MAX

Description "Fixed" "Fixed" "Fixed" "Fixed" "Fixed" "Fixed" "Fixed" "Fixed" "Constraint""Constraint"Tag Name Coil Inlet Pass 6 Pass 7 Coil Outlet Coil Inlet Pass 6 Pass 7 Coil OutletCoil DP Tube TUnit BiasUnit Mult

Units (Y/N) mm mm mm mm mm/day mm/day mm/day mm/day kPa C01-Jan-19 00:00:00 No 0.0 0.0 0.0 0.0 0.00 1.80 1.90 3.50 102.0 965.001-Jan-19 06:00:00 No 0.0 0.5 0.5 0.9 0.00 0.19 0.19 0.36 103.6 975.301-Jan-19 12:00:00 No 0.0 0.5 0.5 1.0 0.00 0.19 0.19 0.36 103.9 976.301-Jan-19 18:00:00 No 0.0 0.6 0.6 1.1 0.00 0.19 0.19 0.36 104.1 977.302-Jan-19 00:00:00 No 0.0 0.6 0.6 1.2 0.00 0.19 0.20 0.36 104.4 978.402-Jan-19 06:00:00 No 0.0 0.7 0.7 1.3 0.00 0.19 0.19 0.36 104.6 979.302-Jan-19 12:00:00 No 0.0 0.7 0.7 1.3 0.00 0.19 0.20 0.36 104.9 980.402-Jan-19 18:00:00 No 0.0 0.7 0.8 1.4 0.00 0.19 0.19 0.35 105.1 981.303-Jan-19 00:00:00 No 0.0 0.8 0.8 1.5 0.00 0.19 0.20 0.36 105.4 982.403-Jan-19 06:00:00 No 0.0 0.8 0.9 1.6 0.00 0.19 0.20 0.36 104.9 983.303-Jan-19 12:00:00 No 0.0 0.9 0.9 1.7 0.00 0.19 0.20 0.36 105.1 984.303-Jan-19 18:00:00 No 0.0 0.9 1.0 1.8 0.00 0.19 0.20 0.36 105.4 985.304-Jan-19 00:00:00 No 0.0 1.0 1.0 1.9 0.00 0.19 0.20 0.36 105.6 986.304-Jan-19 06:00:00 No 0.0 1.0 1.1 2.0 0.00 0.19 0.20 0.35 105.8 987.204-Jan-19 12:00:00 No 0.0 1.1 1.1 2.1 0.00 0.19 0.20 0.35 106.1 988.104-Jan-19 18:00:00 No 0.0 1.1 1.2 2.1 0.00 0.19 0.20 0.35 106.3 989.105-Jan-19 00:00:00 No 0.0 1.2 1.2 2.2 0.00 0.19 0.20 0.35 106.6 990.105-Jan-19 06:00:00 No 0.0 1.2 1.3 2.3 0.00 0.19 0.20 0.35 106.8 990.9

SavePoint

START

STOP

SAVE POINTSAVE POINT

0

2

4

6

8

10

12

14

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Coke

Thi

ckne

ss [m

m]

Coke Thickness

Coil Outlet

Coil Intlet

800

840

880

920

960

1000

1040

1080

1120

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Tem

pera

ture

Tube Temp.

Max.Tube Temp.

COT

Tube Temperature







SavePoint

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STOP


0

2

4

6

8

10

12

14

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Coke

Thi

ckne

ss [m

m]

Coke Thickness

Coil Outlet

Coil Intlet

800

840

880

920

960

1000

1040

1080

1120

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Tem

pera

ture

Tube Temp.

Max.Tube Temp.

COT

Tube Temperature







SavePoint

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STOP


0

2

4

6

8

10

12

14

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Coke

Thi

ckne

ss [m

m]

Coke Thickness

Coil Outlet

Coil Intlet

800

840

880

920

960

1000

1040

1080

1120

2019/1/1 2019/1/15 2019/1/29 2019/2/12

Tem

pera

ture

Tube Temp.

Max.Tube Temp.

COT

Tube Temperature

Hydrocarbon fluids are complex mixtures of many chemical species. This poses a challenge for characteriza�on using conven�onal methods,

where hypothe�cal components need to be created for each sample, blends and products.

Symmetry’ s PIONA molecular structure characteriza�on approach represents hydrocarbon fluids in terms of chemical families and carbon

number. The structures used are the PIONA group: Paraffins, iso-Paraffins, Olefins, Naphthenes and different forms of Aroma�cs. We can

capture the essen�al chemistry of the fluids and blends rigorously to calculate chemical and physical proper�es. This approach can also

mechanis�cally predict kine�c rates using only a limited number of components. This allows the user to perform highly accurate feed blending

studies, including reac�on kine�cs predic�on.

P I O N A A-Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+P I O N A A-

Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+ P I O N A A-Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+

P I O N A A-Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+P I O N A A-

Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+

P I O N A A-Dehyd

A-S,N,V

C1C2

C[3-4]C[5-6]

C[7-8]C[9-11]C[12-14]

C[15-17]C[18-20]

C[21-24]C[25-28]

C29+

Ethane

Naphtha Gas Oil

Propane C4LPGBlending Feed

Service time study.

Cracking furnace feed blending.

Custom Furnace Geometry InputThe PIONA molecular-structure-characterization approach opens the door for rigorous reaction kinetics prediction. The cracking furnace’s rigorous kinetic engine can describe any reaction pathway, including PIONA-based coke growth. Based on the detailed geometry input for both the radiant box and convection sections, the Symmetry platform will calculate the product yields, radiant/convection heat transfer, and pressure drop. This enables you to study and optimize the operation of cracking furnaces accounting for continuous coke formation across all furnace sections.

Rigorous Coke Growth PredictionThe Symmetry platform’s coke growth prediction accounts for the different factors that could cause reduced service run times over the lifespan of a coil. The cracking furnace unit considers reduced tube cross section, heat flux, and yield changes as coke is formed. Coke also causes an increase in pressure drop and metal tube temperatures, reducing service time.

Naphtha_I

Naphtha_II

Naphtha_III

M_Feed

NaphthaFeed_Preheat

BFW_Preheat

MPreheatBFW

Exhaust

M1

Set_Steam

Super_Heater

Preheat

SHP

Blowdown

HP_Stm

Steam_Drum

ETH1

Fuel_burner

~Feed

Bridge_Wall

TLE

Effluent_to_TLE

Product

Hot_BFWSteam

Simplified convec�on

sec�on

Rigorous convec�on

sec�on

Feed blending

Cracking furnace

H2P C1

P C2O C2

O C3O C4

O C5N C3

N C4N C5

N C6A C6

A C7A C8

A C9A(dh) C9A(dh) C10+

0

5

10

15

20

25

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61

Tube Inlet

Tube Outlet

EthylenePropylene

Naphtha_I

Naphtha_II

Naphtha_III

M_Feed

NaphthaFeed_Preheat

BFW_Preheat

MPreheatBFW

Exhaust

M1

Set_Steam

Super_Heater

Preheat

SHP

Blowdown

HP_Stm

Steam_Drum

ETH1

Fuel_burner

~Feed

Bridge_Wall

TLE

Effluent_to_TLE

Product

Hot_BFWSteam

Simplified convec�on

sec�on

Rigorous convec�on

sec�on

Feed blending

Cracking furnace

H2P C1

P C2O C2

O C3O C4

O C5N C3

N C4N C5

N C6A C6

A C7A C8

A C9A(dh) C9A(dh) C10+

0

5

10

15

20

25

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61

Tube Inlet

Tube Outlet

EthylenePropylene

Aluminum coa�ng effect

800830

860890

920950

0.0

0.2

0.4

0.6

0.8

1.0

Uni

t Of C

oke

Form

ed

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 5 10 15 20 25 30 35 40 45

Service Time [%]

Coke

Thi

ckne

ss [%

]

no coa�ng

Al coa�ng

Cracking furnace in a full simulation environment.

Coke growth kinetic model.

Naphtha feed molecular profiles.

Coke forma�on surface temperature -18 C

Heat transfer model.

Furnace SchedulingThe Symmetry platform’s rigorous yield prediction and simultaneous heat transfer and coke growth solution enables optimization studies on cracking furnace operation scheduling.

Total Ethylene Plant ModelThe Symmetry platform’s comprehensive and user-friendly process simulator enables seamless integration between different processes; it can model a complete ethylene plant in only one flowsheet. The use of rigorous thermodynamics enables proper hydrocarbon-water solubility trending in the quench section and also enables hydrate formation prediction in the cold-box section.

Symmetry’ s rigorous yield predic�on and simultaneous solu�on of heat transfer and coke growth allows for op�miza�on studies on cracking

furnace opera�on scheduling.

1-Ja

n-19

3-Ja

n-19

5-Ja

n-19

7-Ja

n-19

9-Ja

n-19

11-J

an-1

913

-Jan

-19

15-J

an-1

917

-Jan

-19

19-J

an-1

921

-Jan

-19

23-J

an-1

925

-Jan

-19

27-J

an-1

929

-Jan

-19

31-J

an-1

92-

Feb-

194-

Feb-

196-

Feb-

198-

Feb-

1910

-Feb

-19

12-F

eb-1

914

-Feb

-19

16-F

eb-1

918

-Feb

-19

20-F

eb-1

922

-Feb

-19

Furnace DecockingTime [d]

COTOffset [°C]

Start Date Total RunLength [d]

Profits[units]

13 0 1-Jan-19 39 37929 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

13 -3 14-Jan-19 39 37561 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

13 -6 27-Jan-19 39 14494 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

13 -5 10-Feb-19 40 -961 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1

No. Unit Running 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3

C2

C2-C3

Naphtha

Heavy-Naphtha

Run All

Run C2 Furnace

Run C2-C3 Furnace

Run Naphtha Furnace

Run Heavy Naphtha Furnace

DC

DC

DC

E-g3E-g2E-g1

E-q4

E-Q3

C-Q2

T-deC2

T-C3_Splitter

T-DC3

T-C2Splitter

Sep-c4

M2

SepLLV2

T4

Sep-g2

CP1

T1

SQ-6

S-Q3

SQ-4

SQ-5

T2

S-Q8S-Q9

~S-Q7

T3

S-Q18

S-Q12

SepLLV1

S-Q13

S-Q19

S-Q20

S-Q16

S-Q13Mass Flow 18143.64 [ton(metric)/d]

S-Q14

SP2

~S-Q10

S-Q17

S-Q15

S-g3

S-g4

S-g5

Sg-8

Sep-g3

SC-9CP2

S-g6 S-g12

Sep-g4

S-g13CP3

S-g10 S-g16

CP4

S-g14

M1S-g7

S-g11

S-g18S-g19

S-g20

S-g21

SP3

S-g23

~S-g2

S-C22

SQ-21

S-g24

Sg-25

Sep-g1

S-g15

S-g1

Ethane

Exhaust

Steam

BFW

Hot_BFW

Blowdown Product

Fuel

~Hot_Feed

SHP

HP_Stm

Flame

Feed

M1_1

Brn1

Feed_Preheat

BFW_Preheat

MPreheat

Super_Heater

Preheat

SRT4211

V1

Air

Set_Steam

TLE

EffluentBridge_Wall

Steam_Drum

1_C2-FurnaceMixed_Feed

C2_Furnaces

Ethane_Furnace_Count

NaphthaNap_Feed

Feed_Preheat_1

BFW_Preheat_1

MPreheat_1BFW_1

Exhaust_1

M1_2

Set_Steam_1

Super_Heater_1

Preheat_1

SHP_1

Blowdown_1

HP_Stm_1

Steam_Drum_1

SW8

Fuel_burner

~Feed_1

Bridge_Wall_1

TLE_1

Effluent_to_TLE

Product_1

Hot_BFW_1Steam_1

Ethane_Furnace_CountFurnace Count *22.00 [Fraction]

M3

Naphtha_Furnace_Count

1_Nap-Furnace

Nap_Furnaces

Naphtha_Furnace_CountFurnace Count *22.00 [Fraction]

E-Q1

RXN

CRx1

E2E1_2E1_1E1E-g4

Sep-g5

Sep-c1

E-c2E-c1

T-deC1

S-c1 S-c8

S-g17 S-c16

S-c17

S-c18

S-c12

S-c2

S-c27

L-Drier

S-c3

V-Drier

S-c23

Sep-c2

S-c10

S-c9

S-c24

S-c4

S-c20

S2-c32

S-C21

S-c33_C1

S-c22_H2

S-c19

S-c5

S-c6

S-c7M1_3

S-c11

E-c3

S-c13

Sep-c3

S-c15

S-c14

M3_1S-d5S-d4

T-deC2Acet_TOP_Recov 100 [%]

S-d3

S-d3C2== 6.9 [ppm]

S-d6

S-c30S-c31

E-d5

S-d7

S-d8

S-d9_ETHYLENE

S-d10

S-d1

Set1

S-d9_ETHYLENEC2= 99.95 [%]ACETYLENE 0 [ppm]

S-d11

S-d12

S-d13

M4S-d14

RXN

CRx2

S-d15

E-d6

S-d16

Set2

S-d19C3= 5.00 [%]

S-d17

S-d18_CGP

S-d19

S-d18_CGPC3= 95.50 [%]

T-DeC5

E-d7S-d20

Sd12_C4s

S-d25_C5s

M5

S-c25

S-c26

V3

S-c29

S-c28

S-d2

Env1

~SQ-1

Ethylene plant example.

Scheduling of cracking furnace operations.

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Process Software Platform Steam Cracking Furnaces


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Symmetry Process Software Platform Steam Cracking Furnaces