Galactoglucomannan stabilization during the initial kraft cooking of Scots pine

Markus Paananen, Tarja Tamminen, Kaarlo Nieminen, Herbert Sixta (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

23 Citations (Scopus)

Abstract

The behaviour of wood components was studied during kraft cooking of Wiley milled Scots pine (Pinus sylvestris L.) at low temperatures characteristic for the initial phase, but comprising alkali concentrations ranging from 0.31 mol l-1 to 1.55 mol l-1. The results confirmed the extensive dissolution/degradation rate of galactoglucomannan (GGM) already in the beginning of a kraft cook applying standard conditions. More than 70% of GGM was eliminated along with lignin removal of approximately 30%. A relatively high GGM yield increase of almost 2.5% on o.d. (oven dry) wood has been observed when both the temperature and the alkali concentration was raised to 130°C and to approximately 1.5 mol l-1, respectively, suggesting that stopping reactions were favoured over peeling reactions. Parallel to the pronounced stabilization of GGM, arabinoxylan experienced an additional loss of approximately 0.5–0.7% on o.d. wood, presumably owing to dissolution rather than alkaline degradation. A comprehensive kinetic model describing the alkaline degradation of GGM along with the lignin removal has been developed based on Wiley milled Scots pine raw material. The proposed kinetic model combines the alkali-dependent equilibria between ionized species of carbohydrate components with the time-dependent rate expressions of peeling, stopping, and alkaline hydrolysis. The model successfully describes the removal of GGM and lignin during initial kraft cooking. The kinetic expressions for the alkaline hydrolysis of carbohydrates were, however, less reliable owing to the limitation of the experiments to low temperatures only.
Original languageEnglish
Pages (from-to)683-692
Number of pages10
JournalHolzforschung
Volume64
Issue number6
DOIs
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

Fingerprint

Cooking
Lignin
Wood
Peeling
Stabilization
Ovens
Carbohydrates
Degradation
Kinetics
Hydrolysis
Dissolution
Alkalies
Temperature
Raw materials
galactoglucomannan
Experiments

Keywords

  • alkaline degradation
  • alkaline hydrolysis
  • galactoglucomannan
  • kinetics
  • kraft cooking
  • peeling
  • pine
  • stopping

Cite this

Paananen, Markus ; Tamminen, Tarja ; Nieminen, Kaarlo ; Sixta, Herbert. / Galactoglucomannan stabilization during the initial kraft cooking of Scots pine. In: Holzforschung. 2010 ; Vol. 64, No. 6. pp. 683-692.
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abstract = "The behaviour of wood components was studied during kraft cooking of Wiley milled Scots pine (Pinus sylvestris L.) at low temperatures characteristic for the initial phase, but comprising alkali concentrations ranging from 0.31 mol l-1 to 1.55 mol l-1. The results confirmed the extensive dissolution/degradation rate of galactoglucomannan (GGM) already in the beginning of a kraft cook applying standard conditions. More than 70{\%} of GGM was eliminated along with lignin removal of approximately 30{\%}. A relatively high GGM yield increase of almost 2.5{\%} on o.d. (oven dry) wood has been observed when both the temperature and the alkali concentration was raised to 130°C and to approximately 1.5 mol l-1, respectively, suggesting that stopping reactions were favoured over peeling reactions. Parallel to the pronounced stabilization of GGM, arabinoxylan experienced an additional loss of approximately 0.5–0.7{\%} on o.d. wood, presumably owing to dissolution rather than alkaline degradation. A comprehensive kinetic model describing the alkaline degradation of GGM along with the lignin removal has been developed based on Wiley milled Scots pine raw material. The proposed kinetic model combines the alkali-dependent equilibria between ionized species of carbohydrate components with the time-dependent rate expressions of peeling, stopping, and alkaline hydrolysis. The model successfully describes the removal of GGM and lignin during initial kraft cooking. The kinetic expressions for the alkaline hydrolysis of carbohydrates were, however, less reliable owing to the limitation of the experiments to low temperatures only.",
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Galactoglucomannan stabilization during the initial kraft cooking of Scots pine. / Paananen, Markus; Tamminen, Tarja; Nieminen, Kaarlo; Sixta, Herbert (Corresponding Author).

In: Holzforschung, Vol. 64, No. 6, 2010, p. 683-692.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Galactoglucomannan stabilization during the initial kraft cooking of Scots pine

AU - Paananen, Markus

AU - Tamminen, Tarja

AU - Nieminen, Kaarlo

AU - Sixta, Herbert

PY - 2010

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N2 - The behaviour of wood components was studied during kraft cooking of Wiley milled Scots pine (Pinus sylvestris L.) at low temperatures characteristic for the initial phase, but comprising alkali concentrations ranging from 0.31 mol l-1 to 1.55 mol l-1. The results confirmed the extensive dissolution/degradation rate of galactoglucomannan (GGM) already in the beginning of a kraft cook applying standard conditions. More than 70% of GGM was eliminated along with lignin removal of approximately 30%. A relatively high GGM yield increase of almost 2.5% on o.d. (oven dry) wood has been observed when both the temperature and the alkali concentration was raised to 130°C and to approximately 1.5 mol l-1, respectively, suggesting that stopping reactions were favoured over peeling reactions. Parallel to the pronounced stabilization of GGM, arabinoxylan experienced an additional loss of approximately 0.5–0.7% on o.d. wood, presumably owing to dissolution rather than alkaline degradation. A comprehensive kinetic model describing the alkaline degradation of GGM along with the lignin removal has been developed based on Wiley milled Scots pine raw material. The proposed kinetic model combines the alkali-dependent equilibria between ionized species of carbohydrate components with the time-dependent rate expressions of peeling, stopping, and alkaline hydrolysis. The model successfully describes the removal of GGM and lignin during initial kraft cooking. The kinetic expressions for the alkaline hydrolysis of carbohydrates were, however, less reliable owing to the limitation of the experiments to low temperatures only.

AB - The behaviour of wood components was studied during kraft cooking of Wiley milled Scots pine (Pinus sylvestris L.) at low temperatures characteristic for the initial phase, but comprising alkali concentrations ranging from 0.31 mol l-1 to 1.55 mol l-1. The results confirmed the extensive dissolution/degradation rate of galactoglucomannan (GGM) already in the beginning of a kraft cook applying standard conditions. More than 70% of GGM was eliminated along with lignin removal of approximately 30%. A relatively high GGM yield increase of almost 2.5% on o.d. (oven dry) wood has been observed when both the temperature and the alkali concentration was raised to 130°C and to approximately 1.5 mol l-1, respectively, suggesting that stopping reactions were favoured over peeling reactions. Parallel to the pronounced stabilization of GGM, arabinoxylan experienced an additional loss of approximately 0.5–0.7% on o.d. wood, presumably owing to dissolution rather than alkaline degradation. A comprehensive kinetic model describing the alkaline degradation of GGM along with the lignin removal has been developed based on Wiley milled Scots pine raw material. The proposed kinetic model combines the alkali-dependent equilibria between ionized species of carbohydrate components with the time-dependent rate expressions of peeling, stopping, and alkaline hydrolysis. The model successfully describes the removal of GGM and lignin during initial kraft cooking. The kinetic expressions for the alkaline hydrolysis of carbohydrates were, however, less reliable owing to the limitation of the experiments to low temperatures only.

KW - alkaline degradation

KW - alkaline hydrolysis

KW - galactoglucomannan

KW - kinetics

KW - kraft cooking

KW - peeling

KW - pine

KW - stopping

U2 - 10.1515/HF.2010.109

DO - 10.1515/HF.2010.109

M3 - Article

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SN - 0018-3830

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ER -