chemical mechanical pulping of eucalyptus - latest ... · mechanical pulping systems chemical...

Mechanical Pulping Systems

Chemical Mechanical Pulping Of

Eucalyptus

- Latest Development & Comparison

Dr. Eric C. Xu

Andritz Pilot Plant and R&D Tech. Center

My documents\Paper_1\Andritz conference\China_11-04\HYP\HYP of HWDs

Mechanical Pulping Systems Slide No. 2

Different Pulping Processes ( For Virgin Fibers)

Mechanical Pulping

o Stone Ground Wood (SGW, PGW…)

o Refiner Mechanical Pulping (RMP,

TMP)

Chemical Mechanical Pulping (CMP)

o Chemical Pretreatment + Refining

Chemical Pulping

o Kraft (sulfate)

o Sulfite

o Others



Why CMP For Hardwoods? (1)

Small - large capacity (100 to >500 t/d)

Lower capital/investment cost

Higher return from wood resource (higher yield…)

Hardwoods are easy to react with chemicals

Hardwoods need chemical treatment to develop strength

Process is very flexible

“Flexible” means it can use different raw

materials and produce different products



Why CMP For Hardwoods?(2)

HWD CMP have been used in many applications:

o Printing/Writing

• coated papers

• supper calendared

• wood free grades

o Paper Board

o Tissue/fluff

o Newsprint



CMP vs. CP from Aspen (pulp intrinsic property)

0

10

20

30

40

50

60

70

80

90

100

0.20 0.30 0.40 0.50 0.60 0.70 0.80

Handsheet Density (g/cm3)

Ten

sil

e I

nd

ex (

Nm

/g)

CMP

CP

0

10

20

30

40

50

60

70

80

90

100

0.20 0.30 0.40 0.50 0.60 0.70 0.80


Ten

sil

e I

nd

ex (

Nm

/g)

CMP

CP



CMP vs. CP from e. grandis (pulp intrinsic property)

0

10

20

30

40

50

60

70

80

90

0.20 0.40 0.60 0.80


Ten

sil

e I

nd

ex (

N.m

/g)

CMP

CP

0

10

20

30

40

50

60

70

80

90

0.20 0.40 0.60 0.80


Ten

sil

e I

nd

ex (

N.m

/g)

CMP

CP



Synergy Between Aspen CMP and CP

Aspen CP Aspen CMP Mixture

PULP SAMPLE ID K1 K2 H1 H2 C1 C2

(HB) (HT) 20%H1 20%H2

80%K2 80%K2

FREENESS (CSF) 320 274 345 210 312 280

BULK (cm3/g) 1.47 1.43 2.35 1.67 1.62 1.47

TENSILE INDEX (N.m/g) 47.0 50.1 24.3 52.6 45.8 59.3

%STRETCH 2.1 2.2 1.0 2.1 2.4 3.2

T.E.A.(J/m2) 44.0 48.6 9.1 41.8 45.1 80.1

% OPACITY 73.0 72.3 83.6 73.9 76.3 73.0

SCATT. COEFF. (m2/kg) 33.0 32.3 50.0 31.7 35.8 31.6

PULP SAMPLE



Different CMP Technologies

P-RC APMP

o alkaline peroxide treatment before and during refining

o Latest & most advanced technology

BCTMP (sulfite)

o sulfite pretreatment before refining + post bleaching

o Old technology



BCTMP:

Press. Pri .

Refining

Screening

and/or

Cleaning

AP Post

Bleaching

+ Washing

Press. Sec.

Refining

Sulfite Chip

Pretreatment

P-RC APMP:

Interstage HC Tower

Sec. Refining

Screening and

Cleaning

Pri. Refining

(Atm. Inlet)

AP Chip Pretreatment

Press Washing

Comparison Between P-RC APMP & BCTMP

They use similar equipment and main chemicals (alkali + peroxide),

but in different ways…



Intrinsic Property: P-RC APMP pulps are better…

0

10

20

30

40

50

60

70

80

0.20 0.30 0.40 0.50 0.60 0.70


Ten

sile In

dex

(N

.m/g

)

Birch P-RC APMP

Birch BCTMP

Aspen P-RC APMP

Aspen BCTMP



20

25

30

35

40

45

50

55

60

65

10 20 30 40 50 60

Tensile Index (N.m/g)

LS

C (

m2/k

g)

P-RC APMP

BCTMP1

BCTMP2

- all pulps at 300 mL CSF (from mixed NA HWD)

Light Scattering: P-RC APMP pulps are higher…



0

100

200

300

400

500

600

700

SEC (kwh/odmt)

CS

F (

mL

)

P-RC APMP (7%TA)

BCTMP (7%TA)

CTMP (2.5%TA) CTMP ( pH 7)

Energy: P-RC APMP uses much less…



Chemical Consumption: P-RC APMP uses less…

P-RC APMP BCTMP

% Total NaOH 6.0 6.5 7.0 6.5

% H2O2 5.0 5.0 5.0 5.0

% Na2SO3 3.0 3.0

FREENESS (CSF, mL) 301 308 306 306

BULK (cm3/g) 2.22 2.18 1.72 1.91

TENSILE INDEX (N.m/g) 46.8 48.7 49.5 47.7

%ISO BRIGHTNESS 86.4 87.1 86.1 87.1

(birch from Europe)



Different CMP: P -RC APMP vs. BCTMP (HWD)

Pulp Quality Strength: equal or higher

Bulk: equal or higher

LSC: same or better

Bleachability: same or better

Process Capital Cost: lower (no post bleaching)

Energy: lower (normally by 30% or more)

Chemical Cost: same or lower

Yield: higher

Effluent: easier to treat



Global Total APMP Design Capacity

0.0

0.4

0.8

1.2

1.6

2.0

2.4

1998 2000 2002 2004 2006 2008 2010

Year

Tota

l D

esig

ned C

apacity

(AD

MT

/Y x

1,0

00,0

00)



Example of P-RC APMP System (1)



Example of P-RC APMP System (2)

Impregnation Stage

MSD

Impregnator

Washwater

Tank

Chip

washer

Dewatering

Screw

Chip Washing

1st Stage HC Refiner

Cyclone

with PSD

Mainline Refining

SEPF1

Reaction

Bin

Chip

Pump Sump

Chip

Pump

Hydra

Screen

From

Woodyard

Bleaching & Washing

Chip

Pre-Steaming

Bin


SEPF2

MC

Tower

MC-Stock

Pump 1

HC Mixer

Screw Press

HC

Tower

OPTION:

1st Stage MC-Bleaching

Hydra

Screen

OPTION: MC-Stock

Pump 1

OPTION:

Chip Washing System

Impregnation Stage

MSD

Impregnator

Washwater

Tank

Chip

washer

Dewatering

Screw

Chip Washing


Cyclone

with PSD

Mainline Refining

SEPF1

Reaction

Bin

Chip

Pump Sump

Chip

Pump

Hydra

Screen

From

Woodyard

Bleaching & Washing

Chip

Pre-Steaming

Bin


SEPF2

MC

Tower

MC-Stock

Pump 1

HC Mixer

Screw Press

HC

Tower

OPTION:

1st Stage MC-Bleaching

Hydra

Screen

OPTION: MC-Stock

Pump 1

OPTION:

Chip Washing System



Preconditioning Refiner Chemical treatment

P-RC APMP: pulp development



Pulp Property Development of Different

Eucalyptus Woods From South America



e. grandis from different countries in S.A.

e. grandis from different countries were similar in tensile/density property development

They all can develop high tensile strength from HYP

FIGURE 9. TENSILE/DENSITY PROPERTIES - E. Grandis

0

10

20

30

40

50

60

0.2 0.25 0.3 0.35 0.4 0.45 0.5 HANDSHEET DENSITY (g/cm

3)

TE

NS

ILE

IN

DE

X (

NM

/g)

ARGENTINA BRAZIL PARAGUAY VENEZVELA



e. grandis from

different countries

were mostly also

similar in “Tensile

Energy Absorption”

development

They all can

develop high T.E.A.

properties from

HYP

e. grandis from different countries in S.A.

FIGURE 10. T.E.A./TENSILE PROPERTIES - E. Grandis

0

5

10

15

20

25

30

35

40

45

50

0 10 20 30 40 50 60 TENSILE INDEX (N.m/g)

T.E

.A. (J

/M2)

ARGENTINA BRAZIL PARAGUAY VENEZVELA



Different eucalyptus species from S.A.

e. grandis & e. saligna

were similar in

tensile/density

development

e. pilularis, e. dunny

and e. urophylla were

similar in their

tensile/density

development

They all can develop

high tensile properties

from HYP

e.grandis & e.saligna

had better intrinsic

property than the

others

FIGURE 11. TENSILE/DENSITY PROPERTIES - Different Eucalyptus

0

10

20

30

40

50

60

70

0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 HANDSHEET DENSITY (g/cm

3)

TE

NS

ILE

IN

DE

X (

N.M

/g)

E. SALIGNA (P) E. GRANDIS (B) E. PILULARIS (B) E. DUNNII (B) E. UROPHYLLA (B)



Different eucalyptus species from S.A.

They all seemed to

have similar T.E.A.

property development

They all can develop

high T.E.A. properties

from HYP

FIGURE 12. T.E.A./TENSILE PROPERTIES

- Different Eucalyptus

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60 70 TENSILE INDEX (N.m/g)

T.E

.A. (J

/M2)

E. Saligna (P) E. Grandis (B) E. Pilularis (B) E. Dunnii (B) E. Urophylla (B)



CMP vs. chemical pulps from eucalyptus

CMP have lower density (higher bulk) at same tensile or

higher tensile at same density or bulk

0

10

20

30

40

50

60

70

80

90

0 0.2 0.4 0.6 0.8

Handsheet Density (g/cm 3 )

Tensile

Index (

N.m

/g)

E. Saligna P-RC APMP

E. Grandis P-RC APMP

E. Pilularis P-RC APMP

E. Dunny P-RC APMP

E. Urophylla P-RC APMP

eucalyptus market chemical pulps

CP from e. grandis



eucalyptus HYP vs. aspen market BCTMP

eucalyptus CMP have higher tensile at same density/bulk or

higher bulk at same tensile than aspen market pulps

0 10 20 30 40 50 60 70

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Handsheet Density (g/cm

3 )

Tensile

Index (

N.m

/g)

E. Saligna P - RC APMP

E. Grandis P - RC APMP E. Pilularis P - RC APMP E. Dunn ii P - RC APMP E. Urophylla P - RC APMP NA aspen BCTMP market pulps NA maple BCTMP market pulps



Table 1. Eucalyptus P-RC APMP versus Aspen BCTMP Market Pulps

Wood Aspen South American Eucalyptus

Process BCTMP P-RC APMP

Freeness (CSF) (ml) 110-350 110-350

Bulk (cm3/g) 1.6-1.8 2.1-2.3 1.7

Density (g/cm3) 0.63-0.56 0.48-0.44 0.59

Tensile Index (N.m/g) 48-52 50 70-80

a

Tear Index (mN.m2/g) 5.0-5.3 5-6.5 >7

a

Burst Index (kPa.m2/g) 2.4-2.7 2.4 > 3.5

a

Brightness (% ISO) 85 85 85

a

Opacity (%) 76-77 80-85 75-80 b

LSC (m2/kg) < 40

B >45 >40

b

NOTE: a From extrapolation

b Estimated numbers

eucalyptus vs. aspen – printing/writing grades

eucalyptus gave better overall pulp handsheet properties



eucalyptus vs. aspen – paperboard grades

Table 2. Eucalyptus P-RC APMP versus Maple BCTMP

Wood Maplea South American Eucalyptus

Process BCTMP P-RC APMP Freeness CSF (ml) 380-400 380-400 Bulk (cm

3/g) 3.0-3.2 3.4-4.1

Density (g/cm3) 0.31-0.33 0.245-0.295

Tensile Index (N.m/g) 15-18 15-18 Tear Index (mN.m

2/g) 3.0 2.5-3.0

Burst Index (kPa.m2/g) 0.8-1.0 0.4-0.6

Brightness (% ISO) 78-80 78-80 % Opacity 80-83.5 84-90 LSC (m

2/kg) - > 50

Note:

a from Reference [UDY, (1996)]

eucalyptus gave better overall pulp handsheet properties



Summary (1)

CMP proven to be important pulping technology for hardwoods in paper and paperboard industry

Hardwood CMP has better pulp intrinsic property than its CP (higher tensile at same bulk, or higher bulk at same tensile)

There is synergistic effects between hardwood CMP and CP pulps

Among CMP technologies, P-RC APMP is more efficient and provides same or better pulp quality



Summary (2)

Good tensile strength properties can be developed from eucalyptus CMP

Among eucalyptus species investigated, e. grandis and e. saligna have better intrinsic properties than the others

eucalyptus CMP pulps also have better overall pulp properties than aspen market BCTMP pulps

eucalyptus CMP pulps have good potential for paper and paperboard applications



Future Trends

Reduce energy consumption by

o Combination with different chemical and biological treatment

o Combination of different refining strategies

Simplify P-RC APMP system even more

Combination with chemical pulping system to maximize synergies

between two systems

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