[PPT] - Pulping potential of young eucalypts: a comparative study of wood PowerPoint Presentation

SLIDE 1

Pulping potential of young eucalypts: a comparative study of wood and pulp properties of 12 eucalypt species

Duarte Miranda Neiva1,Luís Fernandes2, Solange Araújo1, Ana Lourenço1, Jorge Gominho1, Rogério Simões2, Helena Pereira1

1: Centro de Estudos Florestais, Instituto Superior de Agronomia; Universidade de Lisboa 2: Unidade de Materiais Tẽxteis e Papeleiros, Universidade da Beira Interior

7th ICEP – International Colloquium on Eucalyptus Pulp, May 26-29 2015

Vitória, Espirito Santo, Brazil

SLIDE 2

Outline

Wood chemical composition
Kraft pulping
Fibers morphological characteristics
Pulp and Handsheet properties
Possible end uses
Ashes, Extractives, Lignin, Holocellulose
Yield, kappa number, residual alkali, SWC
Fiber population, length, coarseness
°SR, WRV, bulk, air permeability…
High density papers, high porous papers, printing and

writing papers

SLIDE 3

Wood chemical analysis

0.0 1.0 2.0 3.0

E. globulus
E. ovata
E. grandis
E. saligna
E. maculata
E. viminalis
E. botryoides
E. sideroxylon
E. propinqua
E. resinifera
E. rudis
E. camaldulensis

Ashes

5 10 15 20

E. globulus
E. ovata
E. grandis
E. saligna
E. maculata
E. viminalis
E. botryoides
E. sideroxylon
E. propinqua
E. resinifera
E. rudis
E. camaldulensis

Extractives

Ash content- [0.4-2.2%] Extractives content- [6.1-18.9%]

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55 59 63 67 71

E. globulus
E. ovata
E. grandis
E. saligna
E. maculata
E. viminalis
E. botryoides
E. sideroxylon
E. propinqua
E. resinifera
E. rudis
E. camaldulensis

Holocellulose

Wood chemical analysis

20 24 28 32

E. globulus
E. ovata
E. grandis
E. saligna
E. maculata
E. viminalis
E. botryoides
E. sideroxylon
E. propinqua
E. resinifera
E. rudis
E. camaldulensis

Lignin Lignin content- [22-31%] Holocellulose content- [55-70%]

SLIDE 5

Kraft pulping conditions

Microdisgestors (ca. 100ml)
10 g o.d. wood
4:1 liquor to wood ratio
22% active alkalinity (as Na2O)
30% sulfidity (as Na2O)
165 °C reaction temperature
5 min to achieve maximum temperature
60 min at isothermal conditions

SLIDE 6

Yield

(%)

Kappa number Residual alkali

(% of inicial EA)

E. camaldulensis

39 20 7

E. rudis

41 19 9

E. resinifera

42 17 10

E. propinqua

42 20 12

E. sideroxylon

43 15 12

E. botryoides

44 17 9

E. viminalis

44 15 12

E. maculata

44 24 14

E. saligna

45 14 13

E. grandis

46 14 13

E. ovata

49 13 14

E. globulus

50 12 16

Kraft results

Pulp yield correlates with holocellulose (R2=0.84)
Kappa number correlates with holocellulose (-) and wood density (+) (R2=0.71)
For some species the initial chemical charge was almost depleted during
pulping. Ex: E. camaldulensis

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Specific wood consumption

Higher wood density decreases wood volume needed to produce a certain

amount of pulp

Digester size and wood transportation cost increases with SWC
Although having an average pulp yield E. maculata presented a lowest SWC than
E. globulus

300 400 500 600 700 800 2 3 4 5 6

Wood density

(kg/m3)

SWC (m3 wood / ton pulp)

SWC Wood Density

SLIDE 8

Fiber morphological properties

Coarser fibers are considered to be less conformable than fine fibers

and do not bond as readily

Coarseness correlates with Fibers (-) and wood density (+) (R2=0.89)

Fibers

(millions/g)

Length

(µm, weighted in length)

Coarseness

(mg/ 100m)

E. camaldulensis

29 569 68

E. rudis

30 626 60

E. resinifera

32 629 57

E. propinqua

24 614 76

E. sideroxylon

33 568 59

E. botryoides

26 719 63

E. viminalis

41 598 46

E. maculata

18 748 84

E. saligna

25 708 66

E. grandis

25 759 61

E. ovata

32 608 59

E. globulus

24 727 67

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Pulp and Handsheets

Previously dried pulp
Unbleached and unbeaten pulp
Handsheets with 60 g.m2 basic weight

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14 16 18 20 22 24 26 28

Schopper Riegler (°SR)

Pulp Properties

°SR - rate of drainage of diluted pulp suspension.
°SR for eucalypt pulps should be between 16-24[13]

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90 100 110 120 130 140

Water Retention Value

Pulp Properties

Combined effect of physical/chemical properties measuring pulp water

affinity

For eucalypt pulps (previously dried) should be between 100-130%[13]

SLIDE 12

1.2 1.4 1.6 1.8 2.0 2.2 cm3.g-1

Bulk

Handsheet Properties

Influences almost all physical and mechanical properties.
Lower bulk - denser paper and normally higher fiber collapsibility
Bulk correlates with coarseness (+) and wood density (+) (R2=80)

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500 1000 1500 2000 2500 3000

mL.min-1

Air permeability

Structural property related to sheet pores (number, size, shape and

distribution)

Gives a general idea on the behavior of the paper to other fluids

penetration (such as inks)

Air permeability correlates with bulk (+) (R2=0.89)

Handsheet Properties

SLIDE 14

2 4 6 8 10 12 14 mN.m2.g-1

Tear index

Measures the mechanical work required to continue a tear in the

handsheet

Tear index correlates with bulk (-) (R2=0.71)

Handsheet Properties

SLIDE 15

10 20 30 40 50 N.m.g-1

Tensile index

Direct indication of durability and performance of paper when receiving

tensile stress

Tensile index correlates with bulk (-) (R2=0.92)

Handsheet Properties

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50 70 90 110 130 150 170 190 210 J.m-2

Scott bond

Quantifies the paper surface strength (Z direction).
Scott bond correlates with WRV (+) and bulk (-) (R2=0.92)

Handsheet Properties

SLIDE 17

E. viminalis

Yield (%) 44 Kappa 15 Fibers (millions/g) 41 Coarseness (mg/100m) 4.6 °SR 24 WRV (%) 126 Bulk (cm3/g) 1.4 Air permeability (mL/min) 376 Tear index (mN.m2/g) 11 Tensile Index (Nm/g) 43 Scott bond (J/m2) 166

High fiber population
Low coarseness
Low bulk
Low air permeability
High paper strength properties

Possible end uses

High density papers (glassine, bible paper)

Desired characteristics

SLIDE 18

E. maculata
E. propinqua

Yield (%) 44 42 Kappa 24 20 Fibers (millions/g) 18 24 Coarseness (mg/100m) 8.4 7.6 °SR 16 20.5 WRV (%) 99 114 Bulk (cm3/g) 2.1 2.1 Air permeability (mL/min) 2490 2029 Tear index (mN.m2/g) 3 4 Tensile Index (Nm/g) 16 18 Scott bond (J/m2) 63 90

Low fiber population
High coarseness
High bulk
High air permeability
Low paper strength properties

Possible end uses

High porous and tissue paper

Desired characteristics

SLIDE 19

Printing and writing paper

E. botryoides E. saligna E. grandis E.

vata

E. globulus E.globulus

(Portuguese mill)

Yield (%) 44 45 46 49 50

Kappa

17 14 14 13 12 12-17 Fibers (millions/g) 26 25 25 32 24

Coarseness (mg/100m)

6.3 6.6 6.1 5.9 6.7

°SR

21 20 22 25 19 18 WRV (%) 127 118 113 133 112

Bulk (cm3/g)

1.6 1.7 1.7 1.6 1.8

Air permeability

(mL/min)

700 1143 1171 350 1500

Tear index (mN.m2/g)

12 9 13 10 9 4.4 Tensile Index (Nm/g) 39 38 36 40 32 32.9 Scott bond (J/m2) 142 103 122 169 116

Medium/high fiber population
Good air permeability
Good paper surface strength (Scott bond)
High paper strength propertjes at low ͦSR

Desired characteristics

Possible end uses

SLIDE 20

Conclusions

E. maculata and E. propinqua presented fiber and handsheet

characteristics desired for highly porous and tissue paper

E. viminalis appears to show good fiber and handsheet qualities

for high density papers (glassine, bible)

E. botryoides, E. saligna, E. grandis, E. ovata and E. globulus

appear to be the most suited for printing and writing papers

E. globulus presented the best overall combined results in terms
f kraft pulping, fiber morphology and handsheet properties
Results suggest that the variability in the Eucalypt genus

can be further explored, increasing the number of species to be used by the Pulp and Paper industry

SLIDE 21

Considerations

Edaphoclimatic conditions influence the growth and quality
f the trees, and consequently the pulp produced
Reaction conditions influence the yield and characteristics
f the pulp
It is only possible to optimize the reaction conditions for a

specific end use

The optimization of the reaction conditions should be

different for each species

SLIDE 22

Thanks!

Duarte Miranda Neiva- duarteneiva@isa.ulisboa.pt

This work as been published in Industrial Crops and Products: “Chemical composition and kraft pulping potential of 12 eucalypt species” 66: 89-95 (2015)