Recent Advances in the Chemistry of Eucalyptus Wood Jos C. del Ro, - - PowerPoint PPT Presentation

José C. del Río, Jorge Rencoret, Ana Gutiérrez (IRNAS, Seville, Spain) Ángel T. Martínez (CIB-CSIC, Madrid, Spain) Jorge L. Colodette (UFV, Viçosa, Brazil)

Recent Advances in the Chemistry of Eucalyptus Wood

Eucalyptus is a fast growing tree which wood is the main raw material for paper pulp production in Southwest Europe and Brazil (being also used in other countries) Cultivated area + 20.000.000 ha worldwide…

Eucalyptus for pulp and paper production…

Cultivated Eucalyptus plantations in the World…

• E. grandis
• E. globulus
• E. nitens
• E. maidenii
• E. dunnii

Different Eucalyptus species are used for pulp and paper…

Specie Density (Kg/m3) Active alkali (%) Kappa index Yield (%) Viscosity (ml/g) Residual alkali (g/L) Lipophilic extractives Klason lignin

• E. globulus

600 13.0 16.1 59.5 1413 3.6 0.3 18.7

• E. nitens

450 17.5 16.3 50.4 1177 6.2 0.5 22.5

• E. maidenii

600 18.0 16.5 50.8 1093 1.3 0.5 22.6

• E. grandis

435 17.0 15.7 49.7 1148 9.2 0.6 21.1

• E. dunnii

595 20.0 16.1 48.7 931 15.5 0.5 21.6

Plantation of E. urophylla x E. grandis (E. urograndis)

Eucalyptus urograndis (E. urophylla x E. grandis) is a major eucalyptus hybrid grown in Brazil for pulp and papermaking Very high forest productivity (ca. 60 m3/Ha/year)

… and also eucalyptus hybrids!

Eucalyptus urograndis (E. urophylla x E. grandis) is a major eucalyptus hybrid grown in Brazil for pulp and papermaking Very high forest productivity (ca. 60 m3/Ha/year) Brazilian Network of Eucalyptus Genome Research (Genolyptus Program)

Grattaplagia, D., 2003. Genolyptus. In: Mehoramento Genômico (Borém, A., Gindice, M. and Sediyama, T., eds.). Editora de UFV, Viçosa, MG, Brazil, pp. 51-72.

… and also eucalyptus hybrids!

Acronym Eucalyptus crossings U1xU2

• E. urophylla (Flores IP) x E. urophylla (Timor)

U2xC1

• E. urophylla (Timor) x E. camaldulensis (VM1)

G1xUGL

• E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

U1xUGL

• E. urophylla (Flores IP) X [E. urophylla (R) x E. globulus (R)]

U1xC2

• E. urophylla (Flores IP) x E. camaldulensis(VM2)

C1xC2

• E. camaldulensis (VM1) x E. camaldulensis (VM1)

D1xUGL

• E. dunnii (RG) x [E. urophylla (R) x E. globulus (R)]

D2xGL2

• E. dunnii (R) x E. globulus (R)

D1xD2

• E. dunnii (RG) x E. dunnii (R)

IP

• E. grandis (IP) x E. urophylla (IP)

DGxUGL1 [E. dunnii (R) x E. grandis (R)] x [E. urophylla (R) x E. globulus (R)] DGxU2 [E. dunnii (R) x E. grandis (R)] x E. urophylla (Timor) VCP

• E. grandis (VCP) x E. urophylla (VCP)

DGxC1 [E. dunnii (R) x E. grandis (R)] x E. camaldulensis (VM1) C1xUGL

• E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)]

G1xGL2

• E. grandis (Coffs Harbour)x E. globulus (R)

DGxC1 [E. dunnii (R) x E. grandis (R)] x E. camaldulensis (VM1) C1xUGL

• E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)]

U2xGL1

• E. urophylla (Timor) x E. globulus (R)

C1xUGL

• E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)]

DGxGL2 [E. dunnii (R) x E. grandis (R)] x E. globulus (R)

Annual growth, density and productivity of the different eucalyptus hybrids (from the Genolyptus Program)

• E. urograndis (IP)

… and also eucalyptus hybrids!

FJB Gomes and JL Colodette, Univ. Fed. Viçosa, (unpublished results)

Acronym Moisture, (%) Diameter at breast height, (cm) Height, (m) Average annual increment, (m3/ha/yr) Biomass basic density, (kg/m3) Biomass Productivity, bone (dry ton/ha/yr) Chip bulk density, (kg/m3) U1xU2 54 17.5 24.7 86.0 504 43.3 209 U2xC1 55 14.2 22.8 54.1 547 29.6 220 G1xUGL 53 13.6 20.8 46.2 500 23.1 202 U1xUGL 54 13.6 21.0 46.9 496 23.3 193 U1xC2 53 14.4 22.6 52.9 517 27.4 203 C1xC2 54 9.6 16.0 16.0 533 8.5 207 DGxUGL1 55 14.4 21.9 57.7 449 25.9 193 DGxU2 56 18.5 26.1 101.6 496 50.4 203 C1xUGL 53 9.9 16.8 19.9 519 10.3 220 G1xGL2 54 12.6 20.0 39.3 530 20.8 211 DGxC1 53 15.7 24.3 72.6 500 36.3 213 U2xGL1 52 12.5 20.2 40.1 506 20.3 208 DGxGL2 55 10.0 15.9 28.5 489 13.9 197 U1xD2 54 13.2 19.7 42.6 441 18.8 178 U1xG2 56 15.1 22.2 63.4 518 32.8 228 IP 55 17.6 26.3 80.9 480 38.8 183

IP: commercial E. urograndis hybrid

Wood components

The content and chemical structure of wood components are important parameters in pulp production in terms of… … delignification rates, chemical consumption, pulp yields or pitch deposition!

Cellulose Hemicelluloses Lignin

Non-structural components:

• extractives
• proteins and minerals

Wood components

Structural components:

S G H

OH OH

a b g

p-coumaryl alcohol

OCH3 OH OH

a b g

coniferyl alcohol

OCH3 CH3O OH OH

a b g

sinapyl alcohol

Secondary wall Primary wall S1 S2 Lumen S3 Middle lamella

Lignin

Lignin is a recalcitrant polymer that acts as a glue between the fibers It is formed by three different aromatic units (H, G y S)

OCH3 CH3O OH O HO HO OCH3

b-O-4’

OCH3 CH3O HO OH OCH3 OCH3 O O

b-b’/α-O-γ’ resinol

OCH3 OH OCH3 OH O HO

b-5’/α-O-4’ phenylcoumarane b-1’ /a-O-a’ (spirodienone)

OCH3 OH OH OH CH3O OH O O OH HO OCH3

5-5’ /b-O-4’/a-O-4’ dibenzodioxocin

CH3O OH O OCH3

4-O-5’

O OMe MeO O H O OH OMe MeO

4-O-α’

OCH3 CH3O OH OH HO OCH3 OH O O OH HO O OCH3 CH3O OCH3 O CH3O OCH3 CH3O

Main lignin inter-units linkages:

Lignin

Lignin

The lignin content and its structure greatly influences delignification rates, chemicals consumption and pulp yields… … and the residual lignin is responsible for the dark color of the pulps, that need to be subsequently removed in the bleaching stages

Lipophilic extractives

Woods also contain a low molecular weight fraction soluble in organic solvents (lipophilic fraction) One of the main function of wood extractives is the protection against pathogens. The low degradability of most of these compounds contribute to this resistance, but also

• riginates some problems

during industrial uses

OH

Octacosanol

HO

b-Sitosterol

O

Stigmast-4-en-3-one

(CH)3-(CH2)14-COO

Sitosterol hexadecanoate

O OH O OH HO CH2OH

Sitosteril 3b-D-glucopyranoside Octacosanal

O

Nonacosane Hexadecanoic acid

OH O

Trilinolein

CO-O-CH2 CO-O-CH CO-O-CH2

Wood extractives (lipophilic compounds) are at the origin of the pitch deposits produced during pulp and papermaking… …originating important economic losses!

Lipophilic extractives

β-sitosterol

Wood resin Pitch deposit in eucalypt pulp Pitch deposit in pump filter

• 2. Behaviour of eucalyptus wood

components during kraft cooking and ECF/TCF bleaching

• 1. Chemical composition of

eucalyptus wood components

lipids lignin

Recent advances in Eucalyptus wood chemistry

• E. grandis
• E. globulus
• E. nitens
• E. maidenii
• E. dunnii

Rencoret et al. Holzforschung 61, 165-174, 2007

Lignin in eucalyptus woods

Specie Density (Kg/m3) Active alkali (%) Kappa index Yield (%) Viscosity (ml/g) Residual alkali (g/L) Lipophilic extractives Klason lignin

• E. globulus

600 13.0 16.1 59.5 1413 3.6 0.3 18.7

• E. nitens

450 17.5 16.3 50.4 1177 6.2 0.5 22.5

• E. maidenii

600 18.0 16.5 50.8 1093 1.3 0.5 22.6

• E. grandis

435 17.0 15.7 49.7 1148 9.2 0.6 21.1

• E. dunnii

595 20.0 16.1 48.7 931 15.5 0.5 21.6

H G G G G G G G G G G G G G G S S S S S S S S S S

G

The G units are more “condensed” (C5 linkages) and have more redox potential

S

The presence of two MeO groups confers a lower “condensation degree” and a lower potential redox of the S units

The lignin composition, in terms of the S/G ratio, can influence the delignification of the wood, and hence, chemical consumption, pulp yield and bleaching capabilities

Lignin in eucalyptus woods

• E. grandis
• E. globulus
• E. nitens
• E. maidenii
• E. dunnii

Species Lignin content (%) H:G:S S/G

• E. globulus

18.7 0:28:72 2.6

• E. nitens

22.5 0:32:68 2.1

• E. maidenii

22.6 0:33:67 2.0

• E. grandis

21.1 0:34:66 1.9

• E. dunnii

21.6 0:29:71 2.5

Rencoret et al. Holzforschung 61, 165-174, 2007

High S/G ratios Advantageous for pulping!

Lignin in eucalyptus woods - S/G ratio

• E. globulus presents the

highest S/G ratio and also the lowest lignin content

Lignin in eucalyptus woods - S/G ratio

Acronym Extractives % Ash, % Sugar Composition, % Total lignin % S/G ratio Acetyl groups, % Uronic acids, % TOTAL Celulose Hemicelluloses Glu Xyl Gal Man Ara U1xU2 3,6 0,10 46,1 11,8 0,8 0,8 0,2 30,3 2,8 2,1 3,7 99,5 45,4 20,2 U2xC1 3,4 0,19 45,5 10,7 1,2 1,0 0,2 30,8 2,7 1,9 4,0 98,8 44,4 20,1 G1xUGL 4,9 0,20 43,9 13,0 0,8 0,9 0,2 28,9 2,9 2,7 3,8 99,2 43,0 22,3 U1xUGL 3,6 0,12 44,9 11,7 1,1 0,8 0,2 29,7 3,1 2,4 4,0 98,5 44,1 21,0 U1xC2 2,8 0,13 45,6 10,0 1,4 1,1 0,2 31,3 3,0 1,8 3,8 98,3 44,5 19,6 C1xC2 3,0 0,25 45,6 9,7 1,6 0,9 0,3 31,1 3,0 1,6 4,1 98,0 44,7 19,0 DGxUGL1 2,8 0,20 45,5 13,0 0,9 0,8 0,3 29,2 3,2 2,6 4,0 99,4 44,7 22,4 DGxU2 2,7 0,23 45,3 12,6 0,9 1,0 0,3 29,8 2,6 2,5 4,0 99,2 44,3 22,2 C1xUGL 2,1 0,22 46,0 11,9 1,1 0,9 0,3 30,7 3,2 2,2 4,0 99,3 45,1 21,2 G1xGL2 2,8 0,18 46,4 14,1 1,0 0,8 0,3 27,1 3,5 3,0 3,9 99,6 45,6 23,9 DGxC1 1,9 0,14 47,2 10,8 1,2 0,9 0,3 31,0 2,8 1,8 4,0 99,1 46,3 19,8 U2xGL1 2,5 0,18 45,5 13,4 1,2 0,8 0,3 29,3 3,8 2,6 4,0 99,7 44,8 22,9 DGxGL2 1,9 0,18 45,8 12,9 1,1 1,0 0,3 28,2 2,9 2,5 3,8 97,8 44,8 22,6 U1xD2 3,0 0,14 48,1 11,4 1,0 0,9 0,3 28,6 2,6 2,0 3,9 99,3 47,2 20,4 U1xG2 2,8 0,19 46,8 11,8 1,0 0,8 0,3 30,2 2,6 2,0 4,0 99,7 46,1 20,5 IP 2,3 0,16 49,4 12,0 1,2 0,9 0,3 27,2 2,7 1,9 4,0 99,3 48,5 21,1 VC 3,7 0,18 46,9 11,4 0,8 1,1 0,2 28,4 2,9 2,1 3,8 98,5 45,8 20,5 CC 3,5 0,17 47,4 11,2 1,0 1,1 0,2 28,4 2,4 1,9 3,9 98,7 46,4 20,3

• E. urograndis (IP)

Composition of the woods from the different eucalyptus hybrids from Genolyptus Program All eucalyptus hybrids from the Genolyptus program present high S/G ratios (2.4 – 3.8) Eucalyptus hybrids with crossings with E. globulus (GL) present the highest S/G ratios

FJB Gomes and JL Colodette, Univ. Fed. Viçosa (unpublished results)

Lignin in eucalyptus woods - S/G ratio

Acronym Extractives % Ash, % Sugar Composition, % Total lignin % S/G ratio Acetyl groups, % Uronic acids, % TOTAL Celulose Hemicelluloses Glu Xyl Gal Man Ara U1xU2 3,6 0,10 46,1 11,8 0,8 0,8 0,2 30,3 2,8 2,1 3,7 99,5 45,4 20,2 U2xC1 3,4 0,19 45,5 10,7 1,2 1,0 0,2 30,8 2,7 1,9 4,0 98,8 44,4 20,1 G1xUGL 4,9 0,20 43,9 13,0 0,8 0,9 0,2 28,9 2,9 2,7 3,8 99,2 43,0 22,3 U1xUGL 3,6 0,12 44,9 11,7 1,1 0,8 0,2 29,7 3,1 2,4 4,0 98,5 44,1 21,0 U1xC2 2,8 0,13 45,6 10,0 1,4 1,1 0,2 31,3 3,0 1,8 3,8 98,3 44,5 19,6 C1xC2 3,0 0,25 45,6 9,7 1,6 0,9 0,3 31,1 3,0 1,6 4,1 98,0 44,7 19,0 DGxUGL1 2,8 0,20 45,5 13,0 0,9 0,8 0,3 29,2 3,2 2,6 4,0 99,4 44,7 22,4 DGxU2 2,7 0,23 45,3 12,6 0,9 1,0 0,3 29,8 2,6 2,5 4,0 99,2 44,3 22,2 C1xUGL 2,1 0,22 46,0 11,9 1,1 0,9 0,3 30,7 3,2 2,2 4,0 99,3 45,1 21,2 G1xGL2 2,8 0,18 46,4 14,1 1,0 0,8 0,3 27,1 3,5 3,0 3,9 99,6 45,6 23,9 DGxC1 1,9 0,14 47,2 10,8 1,2 0,9 0,3 31,0 2,8 1,8 4,0 99,1 46,3 19,8 U2xGL1 2,5 0,18 45,5 13,4 1,2 0,8 0,3 29,3 3,8 2,6 4,0 99,7 44,8 22,9 DGxGL2 1,9 0,18 45,8 12,9 1,1 1,0 0,3 28,2 2,9 2,5 3,8 97,8 44,8 22,6 U1xD2 3,0 0,14 48,1 11,4 1,0 0,9 0,3 28,6 2,6 2,0 3,9 99,3 47,2 20,4 U1xG2 2,8 0,19 46,8 11,8 1,0 0,8 0,3 30,2 2,6 2,0 4,0 99,7 46,1 20,5 IP 2,3 0,16 49,4 12,0 1,2 0,9 0,3 27,2 2,7 1,9 4,0 99,3 48,5 21,1 VC 3,7 0,18 46,9 11,4 0,8 1,1 0,2 28,4 2,9 2,1 3,8 98,5 45,8 20,5 CC 3,5 0,17 47,4 11,2 1,0 1,1 0,2 28,4 2,4 1,9 3,9 98,7 46,4 20,3

• E. urograndis (IP)

All eucalyptus hybrids from the Genolyptus program present high S/G ratios (2.4 – 3.8) Eucalyptus hybrids U1xU2, G1xUGL, DGxU2 and IP (E. urograndis) were selected (according to annual growth, density, productivity, lignin content, S/G ratio) for detailed structural analysis

FJB Gomes and JL Colodette, Univ. Fed. Viçosa (unpublished results)

Composition of the woods from the different eucalyptus hybrids from Genolyptus Program

2D-NMR of the MWL from E. globulus

Aliphatic-

• xygenated region

Aromatic region

Lignin in eucalyptus woods - 2D-NMR

Lignin inter-unit linkages

A B C I F D

Lignin units

O O HO HO H3CO

1 6 5 4 3 2 2 ' 6 ' 5 ' 4 ' 3 ' 1 '

a b g

OCH3 H3CO OCH3

β-O-4´

O O O O

a ' b ' g ' a b g

OCH3 OCH3 H3CO OCH3

5 ' 3 ' 2 ' 1 ' 6 ' 4 ' 6 5 4 3 2 1

Resinol

a b g

O HO O OCH3 OCH3 H3CO

3 ' 1 ' 6 ' 5 ' 4 ' 2 ' 6 5 4 3 2 1

Phenylcoumaran

O OCH3 O

a b g

OAr OH HO O

1 ' 6 ' 5 ' 4 ' 3 ' 2 '

a b ' g '

1 6 5 4 3 2

OCH3 H3CO H3CO

'

Spirodienone

O OH

1 6 5 4 3 2

a b g

H3CO OCH3

Cinnamyl alcohol end- groups 75

• E. dunnii
• E. grandis
• E. maidenii
• E. nitens
• E. globulus

2.7 1.7 2.4 2.7 2.9 S/G ratio 75 78 79 79 β-O-4´ aryl ether 11 9 9 9 10 Resinol 4 7 4 4 3 Phenylcoumaran 5 3 4 2 3 Spirodienone 5 6 5 6 5 Cinnamyl end-groups

Percentage of lignin inter-unit linkages in different eucalyptus species

Lignin in eucalyptus woods – Linkages

Rencoret et al. Holzforschung, 62, 514-526, 2008

O O HO HO H3CO

1 6 5 4 3 2 2 ' 6 ' 5 ' 4 ' 3 ' 1 '

a b g

OCH3 H3CO OCH3

β-O-4´

Lignin in eucalyptus woods – Linkages

Highest proportion of β-O-4´ linkages …easily cleaved during pulping! Lowest proportion of β-O-4´ linkages

Rencoret et al. Holzforschung, 62, 514-526, 2008

75

• E. dunnii
• E. grandis
• E. maidenii
• E. nitens
• E. globulus

2.7 1.7 2.4 2.7 2.9 S/G ratio 75 78 79 79 β-O-4´ aryl ether 11 9 9 9 10 Resinol 4 7 4 4 3 Phenylcoumaran 5 3 4 2 3 Spirodienone 5 6 5 6 5 Cinnamyl end-groups

Percentage of lignin inter-unit linkages in different eucalyptus species

Lignin in eucalyptus woods – Linkages

Percentage of lignin inter-unit linkages in eucalyptus hybrids (Genolyptus)

DGxU2 G1xUGL U1xU2 IP

2.2 2.8 2.2 2.2 S/G ratio 75 79 76 76 β-O-4´ aryl ether 11 9 11 11 Resinol 5 5 5 5 Phenylcoumaran 4 3 4 4 Spirodienone 3 3 3 3 Cinnamyl end-groups

Prinsen et al. Ind. Crops & Prod., 36, 572-583, 2012 IP:

• E. grandis (IP) x E. urophylla (IP)

U1xU2:

• E. urophylla (Flores IP) x E. urophylla (Timor)

G1xUGL:

• E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

DGxU2: [E. dunnii (R) x E. grandis (R)] x E. urophylla (Timor)

O O HO HO H3CO

1 6 5 4 3 2 2 ' 6 ' 5 ' 4 ' 3 ' 1 '

a b g

OCH3 H3CO OCH3

β-O-4´

O O O O

a ' b ' g ' a b g

OCH3 OCH3 H3CO OCH3

5 ' 3 ' 2 ' 1 ' 6 ' 4 ' 6 5 4 3 2 1

Resinol

a b g

O HO O OCH3 OCH3 H3CO

3 ' 1 ' 6 ' 5 ' 4 ' 2 ' 6 5 4 3 2 1

Phenylcoumaran

O OCH3 O

a b g

OAr OH HO O

1 ' 6 ' 5 ' 4 ' 3 ' 2 '

a b ' g '

1 6 5 4 3 2

OCH3 H3CO H3CO

'

Spirodienone

O OH

1 6 5 4 3 2

a b g

H3CO OCH3

Cinnamyl alcohol end- groups

Lignin in eucalyptus woods – Linkages

Highest S/G ratio and highest proportion of β-O-4´ linkages …easily cleaved during pulping! Percentage of lignin inter-unit linkages in eucalyptus hybrids (Genolyptus)

DGxU2 G1xUGL U1xU2 IP

2.2 2.8 2.2 2.2 S/G ratio 75 79 76 76 β-O-4´ aryl ether 11 9 11 11 Resinol 5 5 5 5 Phenylcoumaran 4 3 4 4 Spirodienone 3 3 3 3 Cinnamyl end-groups

Prinsen et al. Ind. Crops & Prod., 36, 572-583, 2012

O O HO HO H3CO

1 6 5 4 3 2 2 ' 6 ' 5 ' 4 ' 3 ' 1 '

a b g

OCH3 H3CO OCH3

β-O-4´

IP:

• E. grandis (IP) x E. urophylla (IP)

U1xU2:

• E. urophylla (Flores IP) x E. urophylla (Timor)

G1xUGL:

• E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

DGxU2: [E. dunnii (R) x E. grandis (R)] x E. urophylla (Timor)

Lignin composition and pulp yield

Lignin composition (S/G ratio) can be correlated to pulp yield (very important for breeding programmes)

Lignin composition (S/G ratio) can be correlated to pulp yield (very important for breeding programmes)

Py

• CV (%)

3.3 3.0 1.0 2.7 0.5 0.5 4.8 2.4 1.3 4.0 2.5 2.2 Sample Nº Subspecies Reference Density (kg/m 3 ) Active alkali (%) Viscosity (mL/g) 1

• E. globulus ssp . globulus

T5 580 13.0 1451 2

• E. globulus s

sp . globulus T6 600 13.5 1348 3

• E. globulus ssp . globulus

Plus 522 567 12.0 1528 4

• E. globulus ssp . globulus

Elite 2002 556 14.0 1369 5

• E. globulus ssp . globulus

Elite 5002 438 14.0 1418 6

• E. globulus ssp . globulus

Elite 4009 556 16.0 1217 7

• E. globulus ssp . globulus

Elite 4500 477 16.0 1294 8

• E. globulus ssp . globulus

115 - 2

• PM 10

578 17.0 1174 9

• E. globulus ssp . globulus

334 - 1

• AR 2

613 20.0 1143 10

• E. globulus ssp

. pseudoglobulus 2 547 22.0 1135 11

• E. globulus ssp

. pseudoglobulus 4 663 24.0 1089 12

• E. globulus ssp

. pseudoglobu lus 6 665 26.0 1062 Pulp yield

(%) 59.6 58.9 55.8 55.2 54. 1 52.5 49.8 49.1 46.6 44.8 42.0 40.8 S/G average 5.5 5.0 6.4 5.0 4.0 4.1 4.3 5.3 4.6 3.5 3.5 4.0 GC/MS

CV (%) 5.5 3.5 7.7 4.4 1.5 5.6 9.2 5.2 15.3 8.4 5.8 5.8

Lig/Carb average 0.94 0.75 1.05 0.76 1.13 0.74 1.31 1.43 0.86 0.71 0.58 0.64

High variability in pulp yield even among trees of the same species and similar age! High variability in lignin content and composition among trees of the same species and similar age!

del Río et al. J. Anal. Appl. Pyrol. 74:110-115 (2005)

Lignin composition and pulp yield

R = 0.680

There is a correlation between S/G ratio and pulp yield. Woods having higher S/G ratios present higher pulp yields

1 1 3 2 2

35 40 45 50 55 60 65 2,5 3,5 4,5 5,5 6,5 7,5

Pulp yield %

35 40 45 50 55 60 65 2,5 3,5 4,5 5,5 6,5 7,5

(S/G ratio)Py

35 40 45 50 55 60 65 2,5 3,5 4,5 5,5 6,5 7,5

7 9 4 5 6 7 8 10 11 12

del Río et al. J. Anal. Appl. Pyrol. 74:110-115 (2005)

Lignin composition and pulp yield

By contrast, the lignin/carbohydrate ratio

• btained by Py-GC/MS, did not show any

correlation with the pulp yield. Lignin composition is a more important parameter influencing pulp yield than the lignin content

35 40 45 50 55 60 65 0,5 1,0 1,5 2,0

(Lig/Carb)Py

11 12 9 10 2 4 6 1 3 5 7 8

70 30

Pulp yield %

Paradox: woods with the lowest lignin content present the lowest pulp yield! These woods present the lowest S/G ratios! del Río et al. J. Anal. Appl. Pyrol. 74:110-115 (2005)

Lignin composition and pulp yield

• 2. Behaviour of eucalyptus wood

components during kraft cooking and ECF/TCF bleaching

• 1. Chemical composition of

eucalyptus wood components

lipids lignin

Recent advances in Eucalyptus wood chemistry

• E. grandis W. Hill ex Maiden
• E. globulus Labill
• E. nitens Maiden
• E. maidenii F. Muell
• E. dunnii W. Maiden

Lipophilic compounds in eucalyptus woods

Specie Density (Kg/m3) Active alkali (%) Kappa index Yield (%) Viscosity (ml/g) Residual alkali (g/L) Lipophilic extractives Klason lignin

• E. globulus

600 13.0 16.1 59.5 1413 3.6 0.3 18.7

• E. nitens

450 17.5 16.3 50.4 1177 6.2 0.5 22.5

• E. maidenii

600 18.0 16.5 50.8 1093 1.3 0.5 22.6

• E. grandis

435 17.0 15.7 49.7 1148 9.2 0.6 21.1

• E. dunnii

595 20.0 16.1 48.7 931 15.5 0.5 21.6

• E. urograndis (IP)

Component IP U1U2 G1UGL DGU2 Acetone extractives (lipophilics) 0.6 (0.2) 2.1 (0.2) 2.2 (0.3) 0.9 (0.2) Water soluble material 1.4 1.7 1.8 1.5 Klason lignin 24.2 24.3 24.1 24.5 Acid-soluble lignin 3.0 3.4 3.4 3.1

Lignin and extractives content in selected Eucalyptus hybrids from the Genolyptus program

Lipophilic compounds in eucalyptus woods

IP:

• E. grandis (IP) x E. urophylla (IP)

U1xU2:

• E. urophylla (Flores IP) x E. urophylla (Timor)

G1xUGL:

• E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

DGxU2: [E. dunnii (R) x E. grandis (R)] x E. urophylla (Timor) Prinsen et al. Ind. Crops & Prod., 36, 572-583, 2012

Low content of lipophilic compounds!

Wood chips

GC 5 m

Fatty acids Sterol esters Triglycerides Steroid hydrocarbons Sterols

min 5 10 15 20

GC/MS 12 m

Sterol esters Triglycerides Sterols Steroid hydrocarbons Fatty acids

min 5 10 15 25 20 30

(mainlib) á-S itos terol 40 70 100 130 160 190 220 250 280 310 340 370 400 430 50 100 43 55 69 81 107 145 161 173 199 213 231 255 273 303 314 329 354 381 396 414 HO

MS-Identification

Lipophilic compounds in eucalyptus woods

HO HO HO HO HO HO HO HO O O O O O O O OH O OH HO CH2OH O O

2.5 5 7.5 10 12.5 15 17.5 20 Retention time (min)

Sitosterol Stigmastanol Fucosterol Sterol esters Triglycerides Sitosteryl 3b-D- glucopyranoside Fatty acids C16 C18:1 C18:2 + Steroid ketones Steroid hydrocarbons

Chromatogram of total lipophilic extracts of E. nitens wood

Steroidal compounds

Lipophilic compounds in eucalyptus woods

Wood chips

OH O OH O OH O HO OH O O HO O HO O O O O O O O OCH3 OH O O OH O O OCH3 OH CO-O-CH2 HO-O-CH HO-O-CH2 CO-O-CH2 CO-O-CH CO-O-CH2 OH

2.5 5 7.5 10 12.5 15 17.5 20

Sitosterol C16 C18:1 C18:2 + Stigmastanol Fucosterol Sterol esters Sitosteryl 3b-D- glucopyranoside Triglycerides Fatty acids Steroid ketones Steroid hydrocarbons

Non-steroidal compounds

Retention time (min)

Chromatogram of total lipophilic extracts of E. nitens wood

Lipophilic compounds in eucalyptus woods

Wood chips

Compounds

• E. globulus
• E. nitens
• E. maidenii
• E. grandis
• E. dunnii

Fatty acids 306.7 432.2 200.9 307.4 428.9 -Hydroxyfatty acids 23.9 17.4 13.9 9.1 10.5 Sterols 268.3 543.5 336.2 361.5 272.3 Steroid ketones 37.2 72.0 113.0 59.7 95.4 Steroid Hydrocarbons 31.3 30.5 22.2 19.4 26.6 Fatty alcohols 2.4 7.2 3.9 4.1 2.0 Tocopherols 8.5 6.5 11.5 8.3 10.5 Monoglycerides 117.4 121.4 80.3 58.7 61.7 Monoglycerides of -hydroxyfatty acids 2.4 5.1 1.3 2.3 1.7 Diglycerides 0.4 0.3 tr 0.2 0.6 n-Alkylferulates 5.8 3.4 1.2 1.6 7.9 -Carboxyalkylferulates 22.4 1.2 tr 1.1 3.8 Sterol glycosides 65.1 206.0 68.1 159.5 89.5 Tocopherol esters 5.8 15.9 6.1 6.4 9.7 Sterol esters 250.2 828.5 434.4 214.3 289.6 Triglycerides 11.2 21.0 38.1 15.7 28.0

Lipid composition in eucalyptus woods (mg/kg wood)

HO O O O OH O OH HO CH2OH

Less pitch problems More pitch problems

Free and conjugated (esters and glycosides) sterols are at the origin of pitch deposits during kraft cooking and bleaching of eucalyptus wood !

(del Río et al. J. Chromatogr. A, 823, 457-465, 1998; del Río et al. J. Chromatogr. A, 874, 235-245, 2000)

Lipophilic compounds in eucalyptus woods

Lipid composition in eucalyptus hybrid woods (mg/kg wood) - Genolyptus

Compound IP U1U2 G1UGL DGU2 Fatty Acids 289.7 139.8 310.2 208.0 Squalene 23.3 4.8 13.6 12.8 Sterols 901.5 411.8 731.1 895.4 Steroid ketones 44.7 19.8 60.7 26.5 Steroid hydrocarbons 35.7 16.4 19.3 27.8 Tocopherols 2.1 1.2 6.9 3.7 Monoglycerides 157.4 130.5 201.9 123.0 Diglycerides 23.4 10.4 14.2 15.7 n-Alkylferulates 17.0 9.3 51.6 11.8 Sterol glycosides 130.0 96.5 128.9 177.7 Tocopherol esters 3.3 4.3 9.2 9.0 Sterol esters 384.6 432.6 375.9 346.4 Triglycerides 11.1 4.8 10.3 9.5

Less pitch problems

Lipophilic compounds in eucalyptus woods

More pitch problems More pitch problems

HO O O O OH O OH HO CH2OH

Free and conjugated (esters and glycosides) sterols are at the origin of pitch deposits during kraft cooking and bleaching of eucalyptus wood !

(del Río et al. J. Chromatogr. A, 823, 457-465, 1998; del Río et al. J. Chromatogr. A, 874, 235-245, 2000)

Total acetone extracts Polars Lipophilics

0.5 1.0 1.5

(%)

1 2 3

Seasoning time (months)

Wood seasoning is used to reduced the amounts of wood extractives and hence to reduce pitch problems The total acetone wood extractives are drastically reduced during seasoning (ca. 55% in 3 months), however, most of this reduction is due to the removal of polar compounds (60%) while lipophilics are only reduced ca. 30%

Lipophilic compounds in eucalyptus woods - Seasoning

Gutiérrez et al. J. Wood Chem. Technol. 18:439-446 (1998)

• 55%
• 30%
• 60%

sterols sterol esters fatty acids triglycerides steroid ketones 1 2 3 100 200 300 400 500 600

Seasoning time (months) mg/kg wood

Wood seasoning is used to reduced the amounts of wood extractives and hence to reduce pitch problems The total acetone wood extractives are drastically reduced during seasoning (ca. 55% in 3 months), however, most of this reduction is due to the removal of polar compounds (60%) while lipophilics are only reduced ca. 30%

• 10%
• 35%
• 35%
• 40%

+100% Gutiérrez et al. J. Wood Chem. Technol. 18:439-446 (1998)

Lipophilic compounds in eucalyptus woods - Seasoning

sterols sterol esters fatty acids triglycerides steroid ketones 1 2 3 100 200 300 400 500 600

Seasoning time (months) mg/kg wood

Wood seasoning is used to reduced the amounts of wood extractives and hence to reduce pitch problems Total steroid compounds decrease 25%... and fatty acids and triglycerides 35%... …less pitch problems!

• 10%
• 35%
• 35%
• 40%

+100% Gutiérrez et al. J. Wood Chem. Technol. 18:439-446 (1998)

Lipophilic compounds in eucalyptus woods - Seasoning

• 35%

+30%

Make sure to complete the seasoning time!

Recent advances in Eucalyptus wood chemistry

lignin

• 1. Chemical composition of

eucalyptus wood components

lipids

• 2. Behaviour of eucalyptus wood

components during kraft cooking and ECF/TCF bleaching

Behaviour of eucalypt lignin during pulping and bleaching

O2

O O

Filter Filter Filter Filter Filter Stock

Q Po P

To drying machine O2 H2O2 NaOH O2 DTPA H2SO4

98ºC pH 11 98ºC pH 11 105ºC pH 11 98ºC pH 11

Stock

TCF bleaching sequence

Blow tank Digestor Washing filters Stock Na2S NaOH

Kraft pulping

Wood chips Black liquors Crude pulp

Kappa 14 Brightness 41.2% ISO

Eucalyptus G1xUGL Residual Lignin G1xUGL (kraft kappa 20) Black liquor G1xUGL (kraft kappa 20)

Behaviour of eucalypt lignin during pulping and bleaching

G1xUGL: E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

Behaviour of eucalypt lignin during pulping and bleaching

β-O-4 alkyl-aryl ether β-β resinols β-5 phenylcoumarans S/G ratio

Linkages (per 100 aromatic units)

Wood 75.1 13.4 6.2 4.0 15.5 6.4 1.1 3.0 10.1 5.6 1.0 3.0 Abundance of lignin interunit linkages and S/G ratio in the wood of Eucalyptus, and in the pulp residual lignins and black liquor lignins from kraft pulping at different kappa numbers Kappa 20 Kappa 15 Pulp residual lignins Kappa 20 Kappa 15 Lignin in black liquors

O O HO HO H3CO

1 6 5 4 3 2 2 ' 6 ' 5 ' 4 ' 3 ' 1 '

a b g

OCH3 H3CO OCH3

β-O-4´

O O O O

a ' b ' g ' a b g

OCH3 OCH3 H3CO OCH3

5 ' 3 ' 2 ' 1 ' 6 ' 4 ' 6 5 4 3 2 1

Resinol

a b g

O HO O OCH3 OCH3 H3CO

3 ' 1 ' 6 ' 5 ' 4 ' 2 ' 6 5 4 3 2 1

Phenylcoumaran

Distibution of linkages in pulp residual lignin is similar to native lignin in wood, with a predominance

• f β-O-4 alkyl-aryl ether linkages, but with a significant reduction in their content

2.6 6.2 0.6 6.2 0.8 6.5 0.0 6.0 The lignin in black liquors is enriched in resinol structures and S-units

G1xUGL: E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)]

O2

O O

Filter Filter Filter Filter Filter Stock

Q Po P

To drying machine O2 H2O2 NaOH O2 DTPA H2SO4

98ºC pH 11 98ºC pH 11 105ºC pH 11 98ºC pH 11

Stock

TCF bleaching sequence

Blow tank Digestor Washing filters Stock Na2S NaOH

Kraft pulping

Wood chips Crude pulp

Kappa 14 Brightness 41.2% ISO

OO pulp

Kappa 11 Brightness 55.5% ISO

TCF pulp

Kappa 7 Brightness 87.9% ISO

Behaviour of eucalypt lignin during pulping and bleaching

Blow tank Digestor Washing filters Stock Na2S NaOH

Kraft pulping

Wood chips ECF pulp

Kappa 1 Brightness 90.2% ISO

Behaviour of eucalypt lignin during pulping and bleaching

To drying machine

ECF bleaching sequence

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

Guaiacyl

OH OMe

G

OH OMe

G

OH OMe

G

Syringyl

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

5 10 15 20 25 30 min

Relative abundances

OO pulp (kappa 11) TCF pulp (kappa 7) ECF pulp (kappa 1) carbohydrate peaks

“In situ” Py-GC/MS analysis of eucalypt pulps

Behaviour of eucalypt lignin during pulping and bleaching

21 22 23 24 25 26 27 28 29 minutes

m/z 154 m/z 168 m/z182 m/z 180 m/z 194

S units

15.0 17.5 20.0 22.5 minutes

m/z124 m/z 138 m/z152 m/z150 m/z164

G units

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

Monitorization of individual ions characteristic of different lignin fragments increases sensitivity

Behaviour of eucalypt lignin during pulping and bleaching

OH OMe MeO

S

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe

G

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

OH OMe MeO

S

m/z 124+138+152+150+164+ 154+168+182+180+194

12.5 15.0 17.5 20.0 22.5 25.0 27.5 min

OO pulp (kappa 11) TCF pulp (kappa 7) ECF pulp (kappa 1)

Reconstructed pyrograms of residual lignins in eucalyptus pulps TCF bleaching does not alter the composition of residual lignin ECF bleaching drastically alters the composition of residual lignin –only recalcitrant G-units are found

(S/G 1.9) (S/G 1.6) (S/G < 0.1)

Behaviour of eucalypt lignin during pulping and bleaching

Recent advances in Eucalyptus wood chemistry

lipids lignin

• 2. Behaviour of eucalypt wood

components during kraft cooking and ECF/TCF bleaching

TCF bleaching sequence

Behaviour of eucalypt lipids during pulping and bleaching

Blow tank Digestor Washing filters Stock

O O

Filter Filter Filter Filter Filter Stock

Q Po P

To drying machine

98ºC pH 11 98ºC pH 11 105ºC pH 11 98ºC pH 11

Stock

O-O-Q-PoP

Triglycerides are completely hydrolyzed, sterol esters largely remain and fatty acids are dissolved, but neutrals (i.e. sterols) survive alkaline cooking TCF bleaching does not affect lipid composition! Lipid removal is mostly produced in the washing stages!

sterol esters steroid ketones sitosterol steroid hydrocarbons stigmastanol fucosterol 5 10 15 20 25 30 min

Crude pulp 529 mg/kg pulp

sterol esters Steroid ketones sitosterol steroid hydrocarbons stigmastanol fucosterol 5 10 15 20 25 30 min

OO pulp 426 mg/kg pulp

sterol esters steroid ketones sitosterol steroid hydrocarbons stigmastanol fucosterol 5 10 15 20 25 30 min

TCF pulp 267 mg/kg pulp

5 10

sterols sterol esters steroid hydrocarbons steroid ketones Fatty acids triglycerides

15 20 25 30 min 2110 mg/kg wood

Evolution of the main classes of lipophilic compounds in the process waters Hydrocarbons Sterols Steroid ketones Sterol esters

W1 W2 O Q PoP Twin-Nip

200 400 600 800 1000 1200 1400 mg/10 L

O O Q Po P

TCF bleaching sequence

O-O-Q-PoP

TCF bleaching does not affect lipid composition! Lipid removal is mostly produced in the washing stages!

Behaviour of eucalypt lipids during pulping and bleaching

Stock O Q

TCF bleaching sequence

DTPA

Lipids in TCF pulp

sitosterol esters steroid ketones sitosterol steroid hydrocarbons stigmastanol fucosterol

5 10 15 20 25 30 min

Lipids in ECF pulp

5 10 15 20 25 30 min

steroid ketones steroid hydrocarbons stigmastanol

Stock

ECF bleaching sequence

ClO2 H2O2

ClO2 completely degrades unsaturated sterols (major compounds in eucalypt), and thus will present less “pitch” problems

Gutiérrez et al. Holzforschung, 55:260 (2001)

Behaviour of eucalypt lipids during pulping and bleaching

HO HO HO O O

TCF sequences do not degrade free and esterified sterols (major compounds in eucalypt), and thus will present more “pitch” problems

Po

HO HO HO O O

Concluding remarks Eucalyptus wood is an excellent raw material for pulp and papermaking

• Free and conjugated sterols are responsible for pitch deposition during kraft

pulping of eucalyptus wood. The content varies among the different species.

• E. globulus and hybrid U1xU2 present the lowest content of these compounds
• TCF bleaching does not affect the lipid composition and therefore, special

attention has to be paid to these compounds regarding pitch deposition

• ECF bleaching removes unsaturated sterols, leaving the saturated ones

intact (minor compounds), and therefore will have less pitch problems

• Among the different species, the woods from E. globulus and the hybrid

G1xUGL present the lowest lignin content, the highest S/G ratio and the highest content of β-O-4′ linkages

• Low lignin content (19-26% Klason lignin), high S/G ratios (2.0-4.0) and high

percentage of β-O-4′ alkyl-aryl ether linkages (72-79% of side-chains)

• Implies higher delignification rates, less alkali consumption and therefore

higher pulp yields

• Lignin composition changes among the eucalyptus species, within the same

species and with age

• E. urophyla

The chemical characterization of eucalyptus wood and the study of its main components (lignin and lipids) and their behavior during pulping and bleaching offers a valuable information to improve these

• processes. This knowledge will contribute to a better industrial use
• f this interesting raw material for pulp and paper manufacturing

Concluding remarks

Members of the IRNAS-CSIC team