Recent Advances in the Chemistry of Eucalyptus Wood José C. del Río, Jorge Rencoret, Ana Gutiérrez (IRNAS, Seville, Spain) Ángel T. Martínez (CIB-CSIC, Madrid, Spain) Jorge L. Colodette (UFV, Viçosa, Brazil)
Eucalyptus for pulp and paper production… 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…
Cultivated Eucalyptus plantations in the World…
Different Eucalyptus species are used for pulp and paper… E. globulus E. nitens E. maidenii E. grandis E. dunnii Density Active alkali Yield Viscosity Residual alkali Lipophilic Klason Specie Kappa index (Kg/m 3 ) (%) (%) (ml/g) (g/L) extractives 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
… 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 m 3 /Ha/year) Plantation of E. urophylla x E. grandis (E. urograndis)
… and also eucalyptus hybrids! Brazilian Network of Eucalyptus Genome Eucalyptus urograndis Research (Genolyptus Program) ( E. urophylla x E. grandis ) is a major eucalyptus hybrid grown in Acronym Eucalyptus crossings Brazil for pulp and papermaking U 1 xU 2 E. urophylla (Flores IP) x E. urophylla (Timor) Very high forest productivity U 2 xC 1 E. urophylla (Timor) x E. camaldulensis (VM1) G 1 xUGL E. grandis (Coffs Harbour) x [E. urophylla (R) x E. globulus (R)] ( ca. 60 m 3 /Ha/year) U 1 xUGL E. urophylla (Flores IP) X [E. urophylla (R) x E. globulus (R)] U 1 xC 2 E. urophylla (Flores IP) x E. camaldulensis(VM2) C 1 xC 2 E. camaldulensis (VM1) x E. camaldulensis (VM1) D 1 xUGL E. dunnii (RG) x [ E. urophylla (R) x E. globulus (R)] D 2 xGL 2 E. dunnii (R) x E. globulus (R) D 1 xD 2 E. dunnii (RG) x E. dunnii (R) IP E. grandis (IP) x E. urophylla (IP) DGxUGL 1 [E. dunnii (R) x E. grandis (R)] x [E. urophylla (R) x E. globulus (R)] DGxU 2 [E. dunnii (R) x E. grandis (R)] x E. urophylla (Timor) VCP E. grandis (VCP) x E. urophylla (VCP) DGxC 1 [E. dunnii (R) x E. grandis (R)] x E. camaldulensis (VM1) C 1 xUGL E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)] G 1 xGL 2 E. grandis (Coffs Harbour)x E. globulus (R) DGxC 1 [E. dunnii (R) x E. grandis (R)] x E. camaldulensis (VM1) C 1 xUGL E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)] U 2 xGL 1 E. urophylla (Timor) x E. globulus (R) C 1 xUGL E. camaldulensis (VM1) x [E. urophylla (R) x E. globulus (R)] DGxGL 2 [E. dunnii (R) x E. grandis (R)] x E. globulus (R) 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! Annual growth, density and productivity of the different eucalyptus hybrids (from the Genolyptus Program ) Acronym Moisture, Diameter at Height, Average annual Biomass Biomass Chip bulk (%) breast height, (m) increment, basic density, Productivity, bone density, (m 3 /ha/yr) (kg/m 3 ) (kg/m 3 ) (cm) (dry ton/ha/yr) U 1 xU 2 54 17.5 24.7 86.0 504 43.3 209 U 2 xC 1 55 14.2 22.8 54.1 547 29.6 220 G 1 xUGL 53 13.6 20.8 46.2 500 23.1 202 U 1 xUGL 54 13.6 21.0 46.9 496 23.3 193 U 1 xC 2 53 14.4 22.6 52.9 517 27.4 203 C 1 xC 2 54 9.6 16.0 16.0 533 8.5 207 DGxUGL 1 55 14.4 21.9 57.7 449 25.9 193 DGxU 2 56 18.5 26.1 101.6 496 50.4 203 C 1 xUGL 53 9.9 16.8 19.9 519 10.3 220 G 1 xGL 2 54 12.6 20.0 39.3 530 20.8 211 DGxC 1 53 15.7 24.3 72.6 500 36.3 213 U 2 xGL 1 52 12.5 20.2 40.1 506 20.3 208 DGxGL 2 55 10.0 15.9 28.5 489 13.9 197 U 1 xD 2 54 13.2 19.7 42.6 441 18.8 178 U 1 xG 2 56 15.1 22.2 63.4 518 32.8 228 IP 55 17.6 26.3 80.9 480 38.8 183 FJB Gomes and JL Colodette, Univ. Fed. Viçosa, (unpublished results) E. urograndis (IP) 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!
Wood components Structural components: Cellulose Hemicelluloses Lignin Non-structural components: • extractives • proteins and minerals
Lignin Lignin is a recalcitrant OH OH OH g g g polymer that acts as a glue b b b a a a between the fibers G H S It is formed by three different OCH 3 CH 3 O OCH 3 OH OH aromatic units (H, G y S) OH p -coumaryl alcohol coniferyl alcohol sinapyl alcohol Lumen S3 S2 Secondary wall S1 Primary wall Middle lamella
Lignin Main lignin inter-units linkages: OH MeO OH HO O H O HO OMe O OCH 3 HO OCH 3 O CH 3 O O OH MeO OMe OCH 3 CH 3 O OCH 3 4- O - 5’ O OH OCH 3 OH b - O - 4’ b - 5’/ α -O- 4’ 4- O - α ’ OH OH phenylcoumarane OCH 3 OH OCH 3 OH OCH 3 O O OCH 3 CH 3 O OCH 3 CH 3 O OCH 3 CH 3 O OH O OH O O O HO OH CH 3 O O OH OH HO HO OCH 3 CH 3 O OCH 3 CH 3 O HO OCH 3 OCH 3 O b - b ’ / α - O - γ’ OH / b - O - 4’/ a - O - 4’ 5- 5’ resinol b - 1’ / a -O- a ’ (spirodienone) dibenzodioxocin
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 O Woods also contain a low OH molecular weight fraction Hexadecanoic acid soluble in organic solvents (lipophilic fraction) HO Nonacosane b -Sitosterol OH Octacosanol O O Octacosanal Stigmast-4-en-3-one One of the main function of CH 2 OH O wood extractives is the OH O HO protection against pathogens. (CH) 3 -(CH 2 ) 14 -COO OH Sitosteril 3 b - D -glucopyranoside Sitosterol hexadecanoate The low degradability of most of these compounds contribute to this resistance, but also CO-O-CH 2 originates some problems CO-O-CH during industrial uses CO-O-CH 2 Trilinolein
Lipophilic extractives Wood resin Pitch deposit in eucalypt pulp Pitch deposit in pump filter Wood extractives (lipophilic compounds) are at the origin of the pitch deposits produced during pulp and papermaking … … originating important economic losses! β -sitosterol
Recent advances in Eucalyptus wood chemistry 1. Chemical composition of eucalyptus wood components lipids lignin 2. Behaviour of eucalyptus wood components during kraft cooking and ECF/TCF bleaching
Lignin in eucalyptus woods E. globulus E. nitens E. maidenii E. grandis E. dunnii Density Active alkali Yield Viscosity Residual alkali Lipophilic Klason Specie Kappa index (Kg/m 3 ) (%) (%) (ml/g) (g/L) extractives 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 Rencoret et al. Holzforschung 61, 165-174, 2007
Lignin in eucalyptus woods 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 S G S The presence of two G S MeO groups confers a G G S lower “condensation G degree” and a lower G S S potential redox of the S S G units S G G S G H S G The G units are more G G “condensed” (C 5 G G linkages) and have more redox potential S
Lignin in eucalyptus woods - S/G ratio E. globulus E. nitens E. maidenii E. grandis E. dunnii H:G:S S/G Lignin content (%) Species High S/G ratios Advantageous for pulping! E. globulus 18.7 0:28:72 2.6 E. nitens 22.5 0:32:68 2.1 E. globulus presents the E. maidenii 22.6 0:33:67 2.0 highest S/G ratio and also the E. grandis 21.1 0:34:66 1.9 lowest lignin content E. dunnii 21.6 0:29:71 2.5 Rencoret et al. Holzforschung 61, 165-174, 2007
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