Characterization of black liquors from kraft pulping of first-thinning Scots pine (Pinus sylvestris L.)

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Riikka Rautiainen ◽  
Raimo Alén
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Black Liquor ◽  
Outer Part ◽  
Short Fiber ◽  
Kraft Pulping ◽  
Hydroxy Acids ◽  
Stem Wood ◽  
Black Liquors ◽  
Average Molecular Masses

Abstract Formation of hydroxy acids and soluble lignin fragments was investigated during conventional kraft pulping of first-thinning Scots pine (Pinus sylvestris L.) stem wood and its long-fiber outer part and short-fiber inner part. The results indicate that there are characteristic differences in the formation of hydroxy acids in these specific tissues, due to the slightly different contents of cellulose, hemicelluloses, and lignin. Notable are the differences in the formation of xylan-derived acids (2-hydroxybutanoic and xyloisosaccharinic acids) and glucomannan- and cellulose-derived acids (3,4-dideoxy-pentonic and glucoisosaccharinic acids). In contrast, no significant differences were found in the average molecular masses of the dissolved lignins in these black liquors. Finally, the black liquor from the outer part of first-thinning pine was shown to have similar properties as the black liquor from the reference mature wood material.

Papermaking properties of the ECF-bleached kraft pulps from first-thinning Scots pine (Pinus sylvestris L.)

Holzforschung ◽  
2007 ◽  
Vol 61 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Riikka Rautiainen ◽  
Raimo Alén
Keyword(s):  
Optical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Outer Part ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kraft Pulps ◽  
Stem Wood ◽  
Softwood Kraft Pulp ◽  
Long Fibers

Abstract First-thinning Scots pine (Pinus sylvestris) and the outer (containing long fibers) and inner (containing short fibers) parts of its stem wood were delignified on a laboratory scale by kraft pulping followed by oxygen-alkali delignification and bleaching with D0(EO)D1(EP)D2. The aim was to evaluate the potential use of the bleached pulps as reinforcing material in various mechanical and chemical pulps. The physical and optical properties of the pulps indicated that only the “outer part pulp”, with rather similar properties to those of a reference softwood kraft pulp, seemed suitable for this purpose. In contrast, materials from first-thinning stem wood and its inner part resulted in lower yields as early as the kraft pulping stage. Rather mediocre strength properties were obtained, but the bleached kraft pulps prepared from the two first thinning-based materials had good optical properties.

scholarly journals Combustion behavior of kraft black liquor droplets from hot water pretreated hardwood and softwood chips

TAPPI Journal ◽  
2016 ◽  
Vol 15 (11) ◽  
pp. 685-691
Author(s):  
CHENGCONG CHEN ◽  
RAIMO ALÉN ◽  
JONI LEHTO ◽  
HANNU PAKKANEN
Keyword(s):  
Black Liquor ◽  
Hot Water ◽  
The Novel ◽  
Hydroxy Acids ◽  
High Molar Mass ◽  
Combustion Behavior ◽  
Process Modification ◽  
Kraft Black Liquor ◽  
Cooking Process ◽  
Black Liquors

This paper describes the combustion behavior of birch and spruce kraft black liquors obtained from an integrated forest biorefinery concept in which a hot water extraction of chips was performed before pulping. This pretreatment, aiming mainly at the recovery of various hemicellulose-derived materials, increased the concentrations of lignin and hydroxy acids in black liquors, compared with those in the reference black liquors without any process modification. On the other hand, the pretreatment decreased the concentrations of volatile acids and other organics (extractives and hemicellulose residues). Because of these characteristic changes, the total burning times (pyrolysis time plus char burning time) of the reference black liquors were somewhat longer than those of black liquors from the modified cooking process. The novel biorefinery based black liquors also swell more than the conventional ones. This phenomenon was primarily associated with the combined effect of high-molar-mass lignin fragments and hydroxy acids. All of the detected changes in combustion behavior were more intense for birch black liquors than for spruce black liquors.

Stabilization, degradation, and dissolution behavior of Scots pine polysaccharides during polysulfide (K-PS) and polysulfide anthraquinone (K-PSAQ) pulping

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1049-1058 ◽  
Author(s):  
Markus Paananen ◽  
Stella Rovio ◽  
Tiina Liitiä ◽  
Herbert Sixta
Keyword(s):  
Scots Pine ◽  
Black Liquor ◽  
Kraft Pulping ◽  
Cooking Time ◽  
Dissolution Behavior ◽  
Pulp Yield ◽  
Yield Increase ◽  
Ion Concentrations ◽  
Kraft Process ◽  
Diffusion Phenomena

Abstract The behavior of Scots pine (Pinus sylvestris L.) polysaccharides was studied during modified kraft pulping processes of wood meal by polysulfide (K-PS) and polysulfide anthraquinone (K-PSAQ) at the hydroxide ion concentrations of 0.50 and 1.55 M [OH-] with a high liquor-to-wood (L/W) ratio of 200. The high L/W ratio was selected for avoiding diffusion phenomena and to be able to focus on the chemistry of polysaccharides. A comparison with the kraft process reference at 160°C revealed a substantial increase in pulp yield (6–7% in K-PS pulping and 7.5–10.5% in K-PSAQ pulping) mainly attributed to galactoglucomannan (GGM) stabilization. Due to the rapid delignification rate at 1.55 M [OH-] concentration, the temperature could be lowered from 160°C to 130°C without a notable prolongation of cooking time. In K-PS pulping at 130°C, no additional GGM stability was observed compared to 160°C, whereas cellulose and arabinoxylan preservation was improved. In K-PSAQ pulping, GGM preservation was also significantly improved. At 130°C, pulp yield increase of approximately 8% in PS pulping and more than 11% in PSAQ pulping was observed. The amount of dissolved softwood hemicelluloses in black liquor was significantly increased at the higher [OH-] level and even further in the presence of PS and AQ. Simultaneously, the formation of hydroxy acids was decreased, indicating a significant stabilization of the dissolved polysaccharide fraction parallel to the pulp polysaccharides.

Role of Wood Extractives in Black Liquor Corrosiveness

CORROSION ◽  
2006 ◽  
Vol 62 (10) ◽  
pp. 911-917 ◽  
Author(s):  
P. E. Hazlewood ◽  
P. M. Singh ◽  
J. S. Hsieh
Keyword(s):  
Carbon Steel ◽  
Wood Species ◽  
Paper Industry ◽  
Black Liquor ◽  
Wood Chip ◽  
Pulp Mill ◽  
Kraft Pulping ◽  
Extractive Content ◽  
Operational Parameters ◽  
Black Liquors

Abstract In the pulp and paper industry, variability in the process and wood source may result in highly corrosive waste liquors, called black liquors, from the Kraft pulping process. Prior research has demonstrated corrosion rates of carbon steel in pulp mill equipment ranging from <0.03 mm/y to >2.54 mm/y, depending on the wood species pulped. In this study wood species-dependent corrosion is confirmed and age-dependent corrosion is investigated as a function of organic extractive content. The composition of the organic portion of black liquor depends largely on the wood species used. Organic components come from extractives in the wood chips or are generated from the degradation of lignin and other wood constituents during the pulping process. Depending upon the wood species used, some black liquor constituents have been identified to increase the corrosiveness of black liquors whereas others may act as corrosion inhibitors. Our research demonstrates the importance of operational parameters for wood species and wood chip usage and delivery to downstream process corrosion. Further, results show the importance of water-extracted organics in wood, such as long chain fatty acids, using a novel methodology for the separation of extractives and lignin breakdown products in the testing of black liquor corrosiveness with carbon steel A516-Grade 70 (UNS K02700).

Strength properties of wind- and snow-damaged stems of Picea sitchensis and Pinus sylvestris in comparison with undamaged trees

1999 ◽  
Vol 29 (5) ◽  
pp. 595-599 ◽  
Author(s):  
A D Cameron ◽  
R A Dunham
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Compression Wood ◽  
Outer Part ◽  
Sitka Spruce ◽  
Strength Properties ◽  
Picea Sitchensis ◽  
Modulus Of Rupture ◽  
Clear Wood ◽  
Pine Trees

This study compared the strength properties of wood taken from Sitka spruce (Picea sitchensis (Bong.) Carr.) and Scots pine (Pinus sylvestris L.) trees damaged as a result of wind and snow. The spruce trees were located in triplets of stems of similar diameter that had snapped, overturned (i.e., uprooted), or remained undamaged as a result of wind and snow. The pine trees were located in pairs of similar-sized stems that had snapped or remained undamaged. None of the pine trees overturned. Clear wood (wood without knots and sloping grain) from the outer part of the stem of snapped Sitka spruce and Scots pine trees was less stiff (lower modulus of elasticity (MOE)) than wood taken from the same location from overturned (spruce only) or standing trees. Modulus of rupture and density were unaffected. Damaged trees of both species were found to have significantly more compression wood within the test samples in comparison with undamaged trees. These findings suggest that trees that either overturn or snap are bending more than undamaged trees (because of their low MOE) thereby introducing a greater component of crown weight to the overall forces acting on the stem, and that this may be associated with compression wood.

Delignification of Bamboo (Bambusa procera acher) Part 2. Characterisation of Kraft Black Liquors from Different Cooking Conditions

Holzforschung ◽  
2003 ◽  
Vol 57 (6) ◽  
pp. 619-626 ◽  
Author(s):  
T. H. M. Vu ◽  
R. Alén ◽  
H. Pakkanen
Keyword(s):  
Chemical Composition ◽  
Carboxylic Acids ◽  
Black Liquor ◽  
Kraft Pulping ◽  
Laboratory Scale ◽  
Black Liquors ◽  
The Individual ◽  
Aliphatic Carboxylic Acids ◽  
Inorganic Constituents ◽  
Cooking Conditions

Summary Bamboo (Bambusa procera acher) was delignified in a laboratory-scale digester by conventional kraft pulping under varying conditions. Pulps with kappa numbers in the range 12.9–56.3 and viscosities in the range 871–1319 ml g−1 were obtained. The chemical composition of the corresponding black liquors was analysed with respect to their main organic and inorganic constituents. The results indicated that the dry solids of the black liquor contained 40–44% lignin, 20–24% aliphatic carboxylic acids, 4–7% polysaccharides and the residual matter (about 30%) consisted mainly of inorganic constituents. Of the monosaccharide moieties detected in the polysaccharides, xylose was predominant, suggesting that xylan was a major hemicellulose constituent in the black liquor. The effect of effective alkali, sulphidity and H-factor of the cook on the formation of the individual constituents in the black liquor is also discussed.

scholarly journals Current state and productivity of age-old experimental plantations of prof. V.D. Ogievsky in the northeastern part of Ukraine

2021 ◽  
Vol 63 (3) ◽  
pp. 195-202
Author(s):  
M. Zhezhkun ◽  
L.V. Demianenko
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Natural Regeneration ◽  
Health Condition ◽  
Pine Plantations ◽  
Mixed Composition ◽  
Natural Origin ◽  
Stem Wood ◽  
Current State ◽  
Pine Stands

Abstract This research is aimed at determining the health condition and productivity of Scots pine (Pinus sylvestris L.) stands created during 1906–1908 on the initiative of Prof. V. D. Ogievsky. The scheme of silvicultural experiments included: determining the influence of different widths and directions of clear felling on the natural regeneration, testing of pine plantations of pure and mixed composition and the choice of methods for their creation. In terms of health condition, 103–105-year-old artificial pine stands are weakened and their health condition is slightly worse compared to the aged pines of natural origin. The productivity of age-old linden-pine plantations is higher than of pure pine plantations, and the stock of stem wood in plantations created by seed sowing and marketability is higher compared to the plantations created by planting seedlings.

Sequenced Anaerobic-Aerobic Treatment of Hemp Black Liquors

1994 ◽  
Vol 29 (5-6) ◽  
pp. 409-419 ◽  
Author(s):  
S. Kortekaas ◽  
H. S. Doma ◽  
S. A. Potapenko ◽  
J. A. Field ◽  
G. Lettinga
Keyword(s):  
Black Liquor ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Strong Increase ◽  
Anaerobic Sludge ◽  
Aerobic Treatment ◽  
Stem Wood ◽  
Soda Pulping ◽  
Black Liquors ◽  
Anaerobic Sludge Blanket

This study evaluates the sequenced anaerobic-aerobic treatment of hemp bark and hemp stem wood black liquors with respect to COD removal efficiency and detoxification. Anaerobic toxicity assays revealed that soda pulping liquors derived from hemp are just as toxic as those derived from wood. Hemp bark and stem wood black liquors caused 50% inhibition at concentrations of 5.9 and 4.5 g COD/l, respectively. Long term experiments were conducted in lab-scale upflow anaerobic sludge blanket (UASB) reactors at 30°C. Black liquor was fed at sub-toxic concentrations (< 4 g COD/l). In the bark column loadings were applied up to 17.5 g COD/l*d with COD and BOD5 efficiencies of 56.0 and 87.9%, respectively. In the stem wood column loadings up to 18.4 g COD/l*d were reached with COD and BOD5 efficiencies of 42.3 and 81.0%, respectively. Aerobic post-treatment displayed only minor extra COD removal and a strong increase of color levels. After sequenced anaerobic-aerobic treatment, the COD removal was 70.9 and 58.4% for bark and stem wood liquor, respectively, whereas the BOD5 removal exceeded 98%. Strong detoxification was accomplished after anaerobic-aerobic treatment, as was demonstrated by anaerobic toxicity assays. After anaerobic-aerobic treatment bemp bark and stem wood black liquors caused 50% inhibition at concentrations of 135 and 21.5 g COD/l, respectively.

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