09-05-Sulzer-Key to Success in Ethylene Plant-VF

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Sulzer Chemtech

14th ROPTC PATTAYA, THAILAND October 19 22, 2009

Sulzer Chemtech Pte Ltd

Key to Success in Ethylene Plant

Quench Water Column Revamp

Lee Siang Hua

Senior Process Engineer


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14th ROPTC_Sulzer | 19-22 Oct 09 | slide 4

Sulzer Chemtech

Background

A Naphtha Cracker in Asia Pacific intended to revamp the existing quench watertower from random packing to structured packing.

Sulzer worked closely with customer and provide full support on process andhydraulic evaluation of the column.

Two cases was considered , i.e. base case and alternative case, to ensure therevamp will enable the column to handle slightly changes of feedstock and

flexibility in operations.

The revamp study was conducted in second quarter of 2007, installation in firstquarter 2008 and the column was started-up successfully in Mid 2008.


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Sulzer Chemtech

Furnace Oil Quench Water

Quench

3-Stage Gas

Compression

Caustic

Tower

Feedstock

e.g. Naphtha, Ethane, Gasoil

4th-Stage Gas

Compression

Fuel

Oil

Dehydration Unit:Activated alumina

Molsieves TEG System

Refrigeration Unit

Cold

Section

Caustic

Soda

Water

Aromatics

Olefins

Steam

PFD - HOT SECTION

Background


6/2314th ROPTC_Sulzer | 19-22 Oct 09 | slide 6

Sulzer Chemtech

Deethanizer

C2Hx

Acetylene Recoverycatalytic hydrogenation

C2H2 Acetylene

C3+

C2H4

Ethylene

C2H6

Ethane (recycle)

C2 Splitter

C4+

C3

Splitter

C3H6

Propylene

C3H8Propane

Demethanizer

C2+

CH4, H2

Depropanizer

C3Hx

Debutanizer

C5+

Hot

Section

EO Plant

PFD - COLD SECTION

Background



Sulzer Chemtech

Background

Reason for Revamp

1. Replacement of existinginternals due to timeworn

2. Upgrade of internals for more

flexibility, higher capacity andlower pressure drop

ID 5.3m

ID 6.7m

Random

packing

Random

packing

Radial vaporinlet device



Sulzer Chemtech

Content

Background

Process Evaluation

Column Internals Selection

Mechanical Design

Job List



Sulzer Chemtech

Process Evaluation

Figure: Nusselt Diagram

Bed1-btm

Bed2-top

Bed2-btm

Bed1-top

0

20

40

60

80

100

120

140

160

180

200

220

0 5000 10000 15000 20000 25000

Reynolds Num ber

Nusselt/Prandtl^(1

/3)

Heat exchange calculation based on paper"Direct Heat and Mass Transfer in StructuredPackings" by L.Spiegel, P.Bomio and R.Hunkelerin Chem. Eng. Process. 35 (1996) 479-485

Experimental tests with the system air/water andair/dibutylphthalate

Calculation of the overall heat transfer coefficient

Plotting the results of this tests against theReynolds Number shows the goodcorrespondence of the different calculationmethods and the possibility of a regressionanalysis

Examination of different industrial columns showsgood results with this calculation

Direct Heat Transfer Correlation



Sulzer Chemtech

Process Evaluation

Packing hydraulic calculation result with Sulzer hydraulic program

The % capacity < Sulzer guideline of 80%.



Sulzer Chemtech

Process Evaluation

Design S/U Operation

ID 5.3m

ID 6.7m

T = 1.5C

p 2.83 mbar

504 t/h, 106C

30.5C

29C

53C

90C

894 kg/h

943 kg/h

MELLAPAK

MELLAGRID

MELLAPAK

Schoepentoeter

ID 5.3m

ID 6.7m

T = 2Cp 50 mbar

596 t/h, 98C

< 33C

31C

43C

89C

880 kg/h

880 kg/h

MELLAPAK

MELLAGRID

MELLAPAK

Schoepentoeter

p 5.37 mbar



Sulzer Chemtech

Content

Revamp Objective

Process Evaluation


Mechanical Design

Job List

Summary



Sulzer Chemtech

Selection of Internals

Key Characteristics:

Concerns:

Sensitivity to fouling

Heat and mass transfer

Pressure drop essential

Capacity

Capacity limitation with existing internals

Fouling problems

Vapor and liquid mal distribution

Bad efficiencies

High energy consumption



Sulzer Chemtech


Packing

Top mixed bed

Mellapak M2X 2 m height

Mellapak M170.X 0.9 m height

Bottom mixed bed

Mellapak M170.X 2.5 m height

Mellagrid MG90.X 0.5 m height



Sulzer Chemtech

Mellapak or MellapakPlus

High Mass Transfer Efficiency

Smooth Surface Good resistance to fouling

Suitable for uplift resistance if needed

Mellagrid:

Geometrical structure as Mellapak

Higher efficiency than conventional grids

Smooth surface

Great resistance to fouling and or Coking

High mechanical stability

Suitable for dismantling and cleaning viawater and or steam jetting




Sulzer Chemtech


Liquid Distributors

VKH2 distributor with drip tube

IV pre-distrubutors

H-pipes transmit liquid to pre-distributors

Hats on arm channels

Advantages

Good for high liquid loads, e.g. greater than 20 m3/m2h

Liquid is discharged laterally from rectangular channels onto the packing

Revamp issues

Large 14" and 20" feed pipes had to be modified and re-used

Welding on-site for modification of existing feed pipe



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Vapor Inlet

Schoepentoeter vane inlet device

High velocity vapor feed in 49" nozzle F-factor of 88 Pa0.5

Advantages

Even distribution of vapor ensures proper vapor / liquid contact

Eliminates erosion of column shell

Can be segmented to fir through vapor nozzle



Sulzer Chemtech

Content

Background

Process Evaluation


Mechanical Design

Job List



Sulzer Chemtech

Mechanical Design

Modified and reused existing feed pipe

New H-pipe from first elbow, welding toexisting feed pipe at site

New trough type liquid distributor

New mixed bed (Mellapak) for bettercapacity and better heat exchange

Modified and reused existing feed pipe

New H-pipe from first flange

New trough type liquid distributor

New mixed bed for better capacity andbetter heat exchange

New Schoepentoeter radial vapor inletdevice

Reuse existing support beam

Reuse existing support beam


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Sulzer Chemtech

Content

Background

Process Evaluation


Mechanical Design

Job List


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Sulzer Chemtech

Job List

1 Gas Cracker

2 Grassroots


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Sulzer Chemtech

Job List

1 Gas Cracker

2 Grassroots


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Sulzer Chemtech

THANKS FOR ATTENTION!

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09-05-Sulzer-Key to Success in Ethylene Plant-VF