paper tech 2008 seminar
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papertechTRANSCRIPT
Implementation of New HWP LineMill Experiences
Paper Tech 2008, Hyderabad
27/06/2008
S. Udayasankar
TNPL
Paper Tech 2008, Hyderabad
Outline …
Introduction to TNPL
Project Development
Flow sheet Overview
Photo Tour
Benefits
Paper Tech 2008, Hyderabad
TAMIL NADU NEWSPRINT AND PAPERS LIMITEDKagithapuram, Tamil Nadu - India
Paper Tech 2008, Hyderabad
Quick Look …
Promoted by Govt. of Tamilnadu in early 80’s
Produces 245000 tonnes of PWP annually
Uses one million tonnes of Bagasse every year
Tie up with 7 sugar mills to procure bagasse in exchange of steam
Largest exporter of PWP from the country
Conserves 30 000 acres of forest land from deforestation
World’s largest bagasse based paper plant at single location.
Leads way in Non wood paper making
Paper Tech 2008, Hyderabad
Scaling new highs...
90000
180000
230000245000
400000
1985 1996 2003 2008 2010
90000
180000
230000245000
400000
1985 1996 2003 2008 2010
Race of excellence has no finishing line
PM
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PM
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t re
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ild
PM
1+
PM
2
PM
1+
PM
2P
os
t M
DP
PM
1+
PM
2+
PM
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t M
EP
PM
1
Figs in Tons
Paper Tech 2008, Hyderabad
Old HWP Line …
Started up in 1985
RM– Eucalyptus hybrid
Capacity – 120 bdtpd
Conventional digesters, BSW,Bleaching
Bleach sequence : C-E/P-H-H
Brightness : 82 % ISO
Viscosity : 5 cps
Obsolete technology
Paper Tech 2008, Hyderabad
Old HWP Line …
Inefficient bleaching sequence
Obsolete technology
High residual chemicals carry over
Low strength properties
High alkali losses off BSW
High chemical consumption
High water consumption
Poor cleanliness
Drawbacks
Under pressure from PMs & ETP
Paper Tech 2008, Hyderabad
Project Concept ...
Chipper House
Modern HW Cooking Line
Closed-loop BSW & Screening
ECF Bleaching
O2 De-
Lignification
Digesters
HW BSW and
Screening
HW Bleaching
Wood Yard
New ChipperHouse
RetaineRetaineddRetireRetireddNewNew
Conversion to ECF of old line was not feasible
Paper Tech 2008, Hyderabad
New HWP Line …
Idea Germinated in 1998
TNPL represented at1998 TAPPI Pulping conference in Montreal
Mill case studies of successful ECF conversions ie., Sappi, George Pacific, Western Pulp were presented in this conference
US EPA recognises ECF bleaching as the BAT
ECF was preferred to TCF
Planning
Best Available Technology
Paper Tech 2008, Hyderabad
THE FUTURE
Quality
Chips
Extended
Delignification
Oxygen
delignification
Brown loop
closure
ECF
D100
EOP
TCF
Ozone
Peroxide
Closed Cycle
Foundation Technologies
Bleaching
Technologies
Closed Cycle
New Fibreline Technologies …
Paper Tech 2008, Hyderabad
ECF Vs TCF…
ECF has become the dominant pulp bleaching method.
ECF commands 67% of world bleached pulp production, as
against 7% for TCF.
TCF pulps have not reached the brightness levels of ECF
bleached pulps.
Higher operational costs & strength problems associated
with TCF bleaching makes it a less desirable process.
No difference in environmental performance between ECF
and TCF bleaching.
Paper Tech 2008, Hyderabad
Mills Visited…
TNPL’s team undertook visits to
Zellstoff Stendal, Berlin, Germany
Ostrand Mill,Sweden
Glatfelter Mill,Springrove, USA
ITC, Bhadrachalam,India
Metso R&D Center, Sundsvall,Sweden
Andritz R&D Center, Glensfalls,USA
Technical Mission
Paper Tech 2008, Hyderabad
Which one ...?Modern batch cooking Continuous cooking
Crying babies Slim spouse
Difficult to manage
Paper Tech 2008, Hyderabad
Plan Review…Raw material
Both systems are equally sensitive to fines
Batch systems are more suitable for low density woods
Batch systems have slight advantage when different species are campaigned
High availability (98%) can be reached in both systems
Any single failure in continuous cooking stops the whole production
Most failures in batch cooking lead only to decreased production
Energy consumption
Parameter Continuous Batch
MP Steam consumption, Kg/BD t 550 600
Power consumption, kWh/BD t 35 30
Modern Batch Vs Continuous Cooking
Paper Tech 2008, Hyderabad
Plan Review …
Cooking yield
No significant difference in cooking yield between the two systems
No significant difference in Kappa variations
No significant difference in Alkali charge
Others
Batch cooking plant is more flexible for production increase
Capacity of continuous cooking plant is limited by the size of the initially selected equipment
Conclusions
Neither of the cooking systems is clearly superior to TNPL
The selection should be based mainly on total cost of the plant
Paper Tech 2008, Hyderabad
Layout Alternatives …
Alternative-1
The location of the new HWP line in the existing workshop area
The existing workshop to be dismantled and relocated
Alternative-2
The location of the new HWP line would be adjacent to the planned
new Bagasse fibre line
Where to locate ?
Paper Tech 2008, Hyderabad
Layout Alternatives …Alternative-1 Alternative-2
Wood yard
PM#1 & 2
New Recovery boiler
CBP Line#2
PM#3
(future)
Paper Tech 2008, Hyderabad
Layout Alternatives .…Alternative-1
+ Short pumping distance to Paper machines
+ Short chip conveying distance to cooking plant
+ Wood storage near to chipping
- Existing workshop to be dismantled and relocated.
- Long pumping distance to Soda recovery plant
Alternative-2
+ Short pumping distance to new recovery plant
- Long pumping distance to Paper machines
- Long conveying distance for chips
- Pith handling to be dismantled and relocated
Conclusion
After summarizing pros and cons, Alternative-1 was chosen for locating the new HWP Line
Paper Tech 2008, Hyderabad
Line Configuration ...
Super batch cooking
Tank Farm
Hot stock screening
Brown stock washing
2 stage Oxygen Delignification
ECF Bleaching
MC Storage
Paper Tech 2008, Hyderabad
Superbatch cooking schematic ...
Tank farm
Superbatch
Super Batch Digester – Plant Model
Paper Tech 2008, Hyderabad
Fibreline schematic ...
Hot stock screeningBrown stock washing
O2 Delignification
ECF Bleaching
Paper Tech 2008, Hyderabad
Bleaching Sequence ...
DHT - EOP - D1
Chlorine dioxide does not delignify as well as chlorine
Bleaching sequence must be adjusted to compensate
>>eg ; Oxygen and Peroxide reinforced extraction (EOP)
Paper Tech 2008, Hyderabad
Colour of pulp ...
Paper Tech 2008, Hyderabad
Key Performance figs...
• Line Capacity 300 bdtpd
• Kappa No. 18
• Alkali charge 18% as Na2O
• Pulp yield 44.5%
• Pulp Brightness 88% ISO
• Water consumption 14 cu.m/Bdt
• MP Steam for Cooking 600 kgs/Bdt
• MP Steam for bleaching 260 kgs/Bdt
• LP steam for bleaching 130 kgs/Bdt
• AOX in bleach effluent 0.3 kg/Bdt
Low energy
Env.friendly
Paper Tech 2008, Hyderabad
Key P&M suppliers ...
Chipping Fulghum, USA
Cooking plant Metso paper
Fiber line Metso paper
DCS Honeywell, India
Field instruments Metso
LC Pumps Sulzer
MC Pumps Metso
Paper Tech 2008, Hyderabad
Civil construction highlights...
Building area 1850 M2
Building dimensions 75 x 25 x 25 M
No. of floors 3 (cooking) , 2 (fibreline)
Cement 2300 T
Steel 650 T
Bleach towers Slip form construction
Completion time 12 months
Cost of civil works Rs.59 million (US$ 1.3
million)
Paper Tech 2008, Hyderabad
Project Implementation…
Photo Tour
Dismantling of Old Work shop
Work shop functioning at new location
Old Workshop
Ground Zero
New HW Pulp Mill –Earth excavation
New HW Pulp Mill Building in progress
Superbatch Digester enters Mill Gate
Digester unloading
Leading to the erection site
Leading to the erection site
Digester lifting to the position
Lifting fixture
Digester lifting to the position
Digesters in position
Cap: 200 m3
Wt : 25T
DCS Control room
A view of the Twin roll presses
PO press
BSW-2
BSW-1
Bleach presses
A view of the fibre line
Discharge tank
DHT,EOP,D1 Towers Chips feed
A view of the reaction towers
D1
EOP
DHT
Blowtank
O2-IIO2- I
A view of Vent gas scrubber
Front view with MC tower
MC Storage1000 m3
EOT crane
Paper Tech 2008, Hyderabad
Specific benefits ...
Benefits envisaged :
Brightness improvement - 82% to 88% ISO.
AOX reduction to 0.3 kgs/bdt
Higher Pulp strength and cleanliness
Reduced Water consumption - 14 m3/ton
Low Atmospheric emissions, Improved
effluent quality
Reduced energy consumption
•Env. Friendly
•High quality pulp
•Energy efficient
Paper Tech 2008, Hyderabad
Specific benefits ...
350 290
0
50100150200
250300350
Kg/BDt
Old HWP New HWP
Specific consumption - LP steam
365
211
0
100
200
300
400
KWh/BDt
Old HWP New HWP
Specific consumption - Power
1700
860
0
500
1000
1500
2000
Kg/BDt
Old HWP New HWP
Specific consumption - MP steam
Paper Tech 2008, Hyderabad
Specific benefits ...
7
0.30
2
4
6
8
Kg/BDt
Old HWP New HWP
AOX in bleach plant effluent
80
33
0
20
40
60
80
Kg/BDt
Old HWP New HWP
COD in bleach plant effluent
70
140
20
40
60
80
Cu.m/BDt
Old HWP New HWP
Specific consumption - Water
Paper Tech 2008, Hyderabad
Thanks
Description Unit Old HWP line
New Hardwood pulp mill
Guaranteed Actual
Capacity BD tpd 120 300 200
Specific consumption
Steam
LP steam
• Digester
• Fibre line
Kg/BDt
--
350
160
130
470
220
MP steam
• Digester
• Fibre line
Kg/BDt
1700
---
600
260
1450
260
Power
• Digester & Fibre line kWh/BDt 365 211 355
Effluent from Bleach plant
• COD
• AOX
80
7.0
33
< 0.3
--
--
Water consumption M3/BDt 70 14 32