Determination of phenomena involved in impregnation of softwood chips.

Part 1. Method for calculating the true penetration degree

Marjo Määttänen (Corresponding Author), P. Tikka

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)

Abstract

In earlier studies the degree of penetration was calculated with a method which gave a penetration degree of over 100%, if mill liquors were used, because the method ignored the diffusion of cooking chemicals and dissolution of wood material. In this paper, a new experimental research method is presented, which allows the penetration of mill liquors to be examined and a new and more accurate calculation method to be derived. The new penetration calculation method takes into account the influence of diffusion and dissolution of wood material in terms of the density of liquor inside wood and the increased void volume caused by yield loss. In the present research, the new penetration calculation method was used for examining the influence of impregnation conditions on the penetration of cooking liquor into mill chips. Although the amount of alkali penetrating into the chips is much lower than what is needed for cooking, a high degree of penetration is important because it is a prerequisite for fast diffusion. Therefore, proper presteaming, high overpressure, and about 30 minutes’ impregnation time should be used in order to achieve a high penetration degree of over 98 % with softwood mill chips using white and black liquor.
Original languageEnglish
Pages (from-to)550-558
Number of pages8
JournalNordic Pulp and Paper Research Journal
Volume27
Issue number3
DOIs
Publication statusPublished - 2012
MoE publication typeA1 Journal article-refereed

Fingerprint

Softwoods
Cooking
softwood
Impregnation
Wood
penetration
Dissolution
cooking
mill
Alkalies
waste liquors
methodology
research methods
alkalis
dissolution
method
overpressure
research method
void

Keywords

  • Impregnation
  • industrial chips
  • mill chips
  • penetration
  • penetration degree
  • softwood chips

Cite this

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title = "Determination of phenomena involved in impregnation of softwood chips.: Part 1. Method for calculating the true penetration degree",
abstract = "In earlier studies the degree of penetration was calculated with a method which gave a penetration degree of over 100{\%}, if mill liquors were used, because the method ignored the diffusion of cooking chemicals and dissolution of wood material. In this paper, a new experimental research method is presented, which allows the penetration of mill liquors to be examined and a new and more accurate calculation method to be derived. The new penetration calculation method takes into account the influence of diffusion and dissolution of wood material in terms of the density of liquor inside wood and the increased void volume caused by yield loss. In the present research, the new penetration calculation method was used for examining the influence of impregnation conditions on the penetration of cooking liquor into mill chips. Although the amount of alkali penetrating into the chips is much lower than what is needed for cooking, a high degree of penetration is important because it is a prerequisite for fast diffusion. Therefore, proper presteaming, high overpressure, and about 30 minutes’ impregnation time should be used in order to achieve a high penetration degree of over 98 {\%} with softwood mill chips using white and black liquor.",
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author = "Marjo M{\"a}{\"a}tt{\"a}nen and P. Tikka",
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T2 - Part 1. Method for calculating the true penetration degree

AU - Määttänen, Marjo

AU - Tikka, P.

PY - 2012

Y1 - 2012

N2 - In earlier studies the degree of penetration was calculated with a method which gave a penetration degree of over 100%, if mill liquors were used, because the method ignored the diffusion of cooking chemicals and dissolution of wood material. In this paper, a new experimental research method is presented, which allows the penetration of mill liquors to be examined and a new and more accurate calculation method to be derived. The new penetration calculation method takes into account the influence of diffusion and dissolution of wood material in terms of the density of liquor inside wood and the increased void volume caused by yield loss. In the present research, the new penetration calculation method was used for examining the influence of impregnation conditions on the penetration of cooking liquor into mill chips. Although the amount of alkali penetrating into the chips is much lower than what is needed for cooking, a high degree of penetration is important because it is a prerequisite for fast diffusion. Therefore, proper presteaming, high overpressure, and about 30 minutes’ impregnation time should be used in order to achieve a high penetration degree of over 98 % with softwood mill chips using white and black liquor.

AB - In earlier studies the degree of penetration was calculated with a method which gave a penetration degree of over 100%, if mill liquors were used, because the method ignored the diffusion of cooking chemicals and dissolution of wood material. In this paper, a new experimental research method is presented, which allows the penetration of mill liquors to be examined and a new and more accurate calculation method to be derived. The new penetration calculation method takes into account the influence of diffusion and dissolution of wood material in terms of the density of liquor inside wood and the increased void volume caused by yield loss. In the present research, the new penetration calculation method was used for examining the influence of impregnation conditions on the penetration of cooking liquor into mill chips. Although the amount of alkali penetrating into the chips is much lower than what is needed for cooking, a high degree of penetration is important because it is a prerequisite for fast diffusion. Therefore, proper presteaming, high overpressure, and about 30 minutes’ impregnation time should be used in order to achieve a high penetration degree of over 98 % with softwood mill chips using white and black liquor.

KW - Impregnation

KW - industrial chips

KW - mill chips

KW - penetration

KW - penetration degree

KW - softwood chips

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DO - 10.3183/NPPRJ-2012-27-03-p550-558

M3 - Article

VL - 27

SP - 550

EP - 558

JO - Nordic Pulp and Paper Research Journal

JF - Nordic Pulp and Paper Research Journal

SN - 0283-2631

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ER -