sc2 cracking furnace
Post on 14-Jan-2016
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SC2 cracking furnace
These chemical converter units are the Pyrolysis Furnaces
Long carbon chain molecules cracking to smaller parts in the special alloy tubes in the radiation zone (800 – 850 °C)
SC-1 block diagram
Information about polymer units of TVK
„…locally large, but globally small, …how can we do anymore? „
Basic behavior of polyolefin units
Sales&M
arketing
Low MI
High MI
HO
MO CO
PO
PolymerUnits
Production
Cyclical industry with frequent transitions on a dynamic market
TVK’s PP in 2012 PP-3 PP-4
Average cycle lenght ~33 days ~31 days
Reactor grades 10~11 17~18
Final product 24 29
Nr. of transitions/cycle 9~10 16~17
Off-spec. ratio 1,1% 0,1%
Transition grade ratio 2,3% 1,7%
TVK’s PE in 2012
PE-1/LD2 PE-1/HD1 PE-2
Average cycle lenght
~24 days ~28 days ~30 days
Reactor grades 7 9 7
Final product 11 10~11 10
Nr. of transitions/cycle
6 4/line 6
Off-spec. ratio 5,1% 1,8% 1,07%
Transition grade ratio
0,8% 0,2%* 0,3%** Transition grades were created in Q4, 2012
PP4PP3
TVK’s polymer technology review
The „troops” that we have
PolyPropylenePP: linear polymer built from propylene and in some cases contains also ethylene
Tradename: Tipplen (TVK)
Three main types: homo PP, random copolymer PP (C2: (C2: 00..5-5-6.56.5%%)) and block copolymer PP (C2:(C2: 5-2 5-255%%))
Properties:
Melt index: 0.2 - 80g/10 min (230oC/2,16 kg)
C2 content: 0.5 – 20wt%
Melting range: 140 – 165oC
Licensors:
PP3; PP4: LyondellBasell / Spheripol (loop Rx with monomer as diluent)
PP-3 Unit – 100 KTA (1989) PP-4 Unit – 180KTA (1999)
Spheripol PP advantage-disadvantage
Bulk Loop vs. Gas phase reactor technology
Higher CAPEX
Easy Temperature Control at Reactors
Shorter Grade Transition Time
Narrower Product Portfolio (It means lower C2 content random
PP, TPO grades)
Lower Volatile Content in PP (Just at CR grades)
Better Catalyst Activity
Low Density Polyethylene
LDPE technologies: autoclave/tubular reactorLDPE-2 Plant started in 1991.Annual capacity: 65 ktProduct
Tradename: TipolenDensity: 0.919 – 0.925 g/cm3
Melt index: 0.2 – 4.6 g/10 min (190oC/2.16 kg)Main application: film blowing
Licensor: LyondellBasell
LDPE technologies: autoclave/tubular reactorLDPE-2 Plant started in 1991.Annual capacity: 65 ktProduct
Tradename: TipolenDensity: 0.919 – 0.925 g/cm3
Melt index: 0.2 – 4.6 g/10 min (190oC/2.16 kg)Main application: film blowing
Licensor: LyondellBasell
tubular
autoclave
LDPE tubular vs. autoclave
Shematic process of LDPE-2 Plant
High/Medium Density Polyethylene
HDPE/MDPE: Polyethylene having only short chain branches on the linear main chain
Tradename: Tipelin (TVK)
Properties:
Density: 0.935 – 0.965 g/cm3
Melt index: 0.1 - 50 g/10 min (190 oC/2,16 kg)
Melting range: 125 – 135oC
Licensor:
PE1/ HDPE-1: Chevron Phillips (loop Rx with light diluent)
PE2 / HDPE-2: Mitsui Chemicals Inc. (stirred tank Rx with heavy diluent)
0,915 0,926 0,940 0,970
No of SCB
HDPEMDPE
LLDPE
PE-1/HDPE-1 Unit – 200KTA (1986)
Treaters
ethylene
isobutane
hexene-1
hydrogen
Loop Reactor(90 – 106°C; 42barg)
Flash Tank (60°C; 0,3barg)
Cyclone
Bag Filter
Dryer (70°C)
Purge Column (75°C)
HDPE fluff to powder silos
Flash Gas to recycling system
PowderSilos
(8pcs)Homogenizer
Additives
• Silo farm (28 silos)• Bagging machines (2 lines)• Truck loading facility
Continuous Intensive Mixer (CIM)
Repellet
Extruder (210°C)
DryerClassifierScales
HDPE pellets
PE-2 / HDPE-2 Unit – 220KTA 2004
Termék
H2
Comonomer
Centrifuge
Dryer / 105°C
Powder Silo
Pellet Silo
TEAL
Solvent tank
Homogenizer
Daily tank
Mixing
silo
Low Polymer (LP)
VOC: ~33 -> 0,1wt%
2/3
1/3
Fresh solvent
Packa-ging
Packa-ging
R1: 85°C/7barg R2: 75°C/2.5barg220°C
Advantages, disadvantages in the HDPE units
PE-1/HDPE1 vs. PE-2/HDPE-2
Less rotation maschine - Higher reliability Excellent diluent recovery Broad density range (0,962-0,935) Lower catalyst costs Less steam consumption Lower volatile content (instead of MDPE) MI correction in the extrusion section
Higher electricity consumption Just monomodal products Longer transitions Lower flexibility
Wider product range (mono and bimodal) Shorter grade transition time High flexibility Lower pressure in the reactor part Start and stop without flaring Lower ESP in the extrusion section Possibility to use C3- instead of purchased
co-monomer
Higher steam consumption in the diluent recovery section
Higher specific diluent consumption Higher volatile content Higher maintenance costs
Process Control - Optimization
Try to find….…keep it…
…automate it.
General process control scheme
Optimization
3 basic rules:1 – Safety2 – Quality3 – Economic goals
The economical situation forces the polymer producers to find „new operating region”, and they would be able to adopt new technics to remained there in every different workpoints.
Weak demand
APC the most common tool for optimization The APC is not a „magic weapon”. This is that tool wich can help us to keep the plant
near to the optimum continuously if the operators are familiare with that. The two most critical behaviors of a polymer plant: Non-linearity, multivariable
Thank you for your kind attention!
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