Paper Tech 2008 Seminar

Implementation of New HWP LineMill Experiences

Paper Tech 2008, Hyderabad

27/06/2008

S. Udayasankar

TNPL


Outline …

Introduction to TNPL

Project Development

Flow sheet Overview

Photo Tour

Benefits


TAMIL NADU NEWSPRINT AND PAPERS LIMITEDKagithapuram, Tamil Nadu - India


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


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

1+

PM

2P

os

t re

bu

ild

PM

1+

PM

2

PM

1+

PM

2P

os

t M

DP

PM

1+

PM

2+

PM

3P

os

t M

EP

PM

1

Figs in Tons


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


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


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


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


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 …


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.


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


Which one ...?Modern batch cooking Continuous cooking

Crying babies Slim spouse

Difficult to manage


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


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


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 ?


Layout Alternatives …Alternative-1 Alternative-2

Wood yard

PM#1 & 2

New Recovery boiler

CBP Line#2

PM#3

(future)


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


Line Configuration ...

Super batch cooking

Tank Farm

Hot stock screening

Brown stock washing

2 stage Oxygen Delignification

ECF Bleaching

MC Storage


Superbatch cooking schematic ...

Tank farm

Superbatch

Super Batch Digester – Plant Model


Fibreline schematic ...

Hot stock screeningBrown stock washing

O2 Delignification

ECF Bleaching


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)


Colour of pulp ...


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


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


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)


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

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


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



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



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


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

Paper Tech 2008 Seminar

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