Kraft pulp yields and wood properties of fertilized red spruce

1980 ◽  
Vol 10 (2) ◽  
pp. 183-189
Author(s):  
Robert K. Shepard Jr. ◽  
James E. Shottafer ◽  
Joseph M. Genco
Keyword(s):  
Kraft Pulp ◽  
Lignin Content ◽  
Volume Growth ◽  
Wood Properties ◽  
Kappa Number ◽  
Red Spruce ◽  
Unit Weight ◽  
Pulp Yield ◽  
Average Yield ◽  
Posttreatment Period

Red spruce (Picearubens Sarg.) near Princeton, Maine, U.S.A. fertilized with 168 kg N/h in 1970 increased in volume growth by nearly 50% over pretreatment rates during the 8-year posttreatment period; specific gravity was not affected. Average pulp yield per unit weight of posttreatment wood from fertilized trees was 1.9% greater than average yield from pretreatment wood, but rejects increased by 2.2% and kappa number by 17.7 mL. Average pulp yield per unit weight of posttreatment wood from unfertilized trees was 1.2% less than from pretreatment wood; rejects were 0.4% less and kappa number 2.6 mL higher. Fertilization increased the lignin content of posttreatment wood by about 3% and the resin content by 2%. Ash content also increased after fertilization.

scholarly journals Chemical composition and fiber properties of fast-growing species in Latvia and its potential for forest bioindustry

2017 ◽  
Vol 66 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Inese Sable ◽  
Uldis Grinfelds ◽  
Laura Vikele ◽  
Linda Rozenberga ◽  
Dagnija Lazdina ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Kraft Pulp ◽  
Lignin Content ◽  
Lodgepole Pine ◽  
Pulp Yield ◽  
Fine Content ◽  
Fast Growing ◽  
Pulp Fibres ◽  
Global Energy Supply ◽  
Fast Growing Species

AbstractBioenergy, including energy from wood, currently provides about 9–13% of the total global energy supply. Every fibre of fast-growing wood has a value for its potential use as a material in both pulp and paper and wood chemical industries. The aim of this study was to assess the chemical composition and fibre’s properties of fast-growing species in Latvia – aspen, hybrid aspen, lodgepole pine, poplar and willow. Results showed a variation of cellulose, lignin, extractives and ash contents among the species. Kraft pulp yield and amount of residual lignin were measured and properties of pulp fibres determined. Form factor and fine content in pulp were measured. Poplar and aspen wood had the highest content of cellulose, while lodgepole pine had the highest lignin content in wood and the longest kraft pulp fibres. Willow had 20% of fines in pulp. Individual results suggest the most suitable application of each species.

Lignin modification in the initial phase of softwood kraft pulp delignification with polyoxometalates (POMs)

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 492-498 ◽  
Author(s):  
Biljana Bujanovic ◽  
Sally A. Ralph ◽  
Richard S. Reiner ◽  
Rajai H. Atalla
Keyword(s):  
Kraft Pulp ◽  
Lignin Content ◽  
Kappa Number ◽  
Ring Cleavage ◽  
Residual Lignin ◽  
Glucose Content ◽  
Lower Glucose ◽  
Softwood Kraft Pulp ◽  
Alkaline Conditions ◽  
Extraneous Material

Abstract Commercial softwood kraft pulp with kappa number 30.5 (KP30.5) was delignified with polyoxometalates (POM, Na5(+2)[SiV1(-0.1)MoW10(+0.1)O40]), and POM-treated kraft pulp of kappa number 23.6 was obtained (KPPOM,23.6). Residual lignin from pulps was isolated by mild acid hydrolysis and characterized by analytical and spectral methods to gain insight into lignin reactions taking place during the initial delignification phase. Lignin from POM-delignified pulp was isolated in lower yield. Comparative analysis of residual lignins (RL-KP30.5, RL-KPPOM,23.6) showed that POM leads to products enriched in carbonyl/carboxyl groups and carbohydrates. POM lignins have a lower molecular mass and a lower content of phenolic hydroxyl and methoxyl groups. Based on these results and FTIR spectra, we suggest that aromatic ring cleavage and quinone formation occur during POM delignification. The degree of lignin-cellulose association increases after POM delignification. Lignin-cellulose association was found to be partially unstable under mild alkaline conditions, as residual lignin isolated after alkaline extraction of KPPOM,23.6 pulp (RL-KPPOM/NaOH) exhibited lower glucose content, higher Klason lignin content, and less extraneous material.

Enhancement of eucalypt pulp yield through extended impregnation cooking

2018 ◽  
Vol 33 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Gustavo B. de Souza ◽  
Jorge Luiz Colodette ◽  
Fernando José Borges Gomes ◽  
Danila Morais de Carvalho
Keyword(s):  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield

AbstractThe improvement caused by eucalypt chip impregnation on kraft pulping performance was assessed for terminating the cook at kappa in the range of 15–27 and at controlled residual effective alkali (REA) of 6–8 g/L NaOH. Extended impregnation cooking of eucalypt chips (EIC) increased about 1 %lignin- and HexA-freescreen yield gains in relation to conventional cooking (CC), regardless of kappa number in the range of 15–27. The EIC technology allows for cooking eucalypt wood to kappa number up to 27, without rejects production, but without significant improvement inlignin- and HexA-freescreen yield and with larger chlorine dioxide (ClO2) consume during bleaching. The optimum kappa number for both CC and EIC cooking was about 19 with similar refinability and strength properties for both technologies, CC and EIC. It was concluded that extended impregnation cooking is an attractive technique for enhancing bleached eucalypt Kraft pulp yield.

Temperature and effective alkali effect on brown pulp kraft cooking

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaqueline Silveira Comelato Favaro ◽  
Gustavo Ventorim ◽  
Iliane Rodrigues de Oliveira ◽  
Cláudia Rodrigues de Oliveira
Keyword(s):  
Lignin Content ◽  
Removal Rate ◽  
Linear Trend ◽  
Total Yield ◽  
Eucalyptus Grandis ◽  
Kappa Number ◽  
Factor H ◽  
Pulp Yield ◽  
Lignin Removal ◽  
Kraft Cooking

Abstract One way to obtain high quality pulp production is to improve selectivity delignification of step, maximize yield. Brown pulp yield and chemical composition were studied, with variation of temperature and effective alkali in Kraft cooking. Considering that these variables directly affect lignin removal rate and final product quality. Industrial wood chips from Eucalyptus grandis x Eucalyptus urophylla hybrids were used in this study. The cooking was performed to obtain pulps with kappa number 13, 15 and 17 for temperatures 155 °C, 160 °C and 165 °C, using the same Factor H (695). Yields were analyzed according to: total yield, rejects content and screened pulp yield. Klason lignin content, wood and pulp sugars, levels of hexenuronic acids in pulp were also determined. Results indicate that lower cooking temperatures are beneficial in relation to cooking performance, selectivity and preservation of xylans. With a screened pulp yield of 57.1 % for KN 17 at the lowest temperature 155 ºC and 55.3 % at the same KN at 165 ºC. The lowest screened pulp yield obtained, 51 %, was for KN 13 at 165 ºC, with 54.1 % with the same KN at 155 ºC. Evidencing a decreasing linear trend of screened pulp yield with temperature increase and kappa number reduction.

scholarly journals Inclusion of a pressurized acidolysis stage in chemical pulp bleaching

BioResources ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 823-840
Author(s):  
Samar K. Bose ◽  
Aaron Leavitt ◽  
Bertil Stromberg ◽  
Dipankar Kanungo ◽  
Raymond C. Francis
Keyword(s):  
Kraft Pulp ◽  
Model Compound ◽  
Lignin Content ◽  
Control Sample ◽  
Major Change ◽  
Pulp Yield ◽  
Pulp Bleaching ◽  
Lignin Model Compound ◽  
Chemical Pulp ◽  
Lignin Model

Hardwood soda-AQ pulps are believed to be rich in benzyl sugar ethers (BSE) that can be partially cleaved by aqueous acidic treatments. The aim of this investigation was to evaluate the effect of acidolysis on final bleached brightness for kraft and soda-AQ (SAQ) hardwood pulps. The increase in final brightness due to acidolysis at 110 °C was twice as high for a eucalyptus SAQ pulp as compared to the kraft pulp. An oxygen delignified maple C-SAQ pulp (carbonate pre-treated SAQ) was acidolyzed at 120 °C and pH 2.6 for 30 min. When 1.60% ClO2 + 0.25% H2O2 on pulp was used in DEPD final bleaching of the control sample a brightness of 91.5% was achieved. When only 1.00% ClO2 + 0.25% H2O2 on pulp was used for the acidolyzed sample a brightness of 92.0% was attained. Analyses of the maple pulp after the acidolysis showed no major change in lignin content, brightness, or pulp yield. The minor changes suggest that a facile reaction such as benzyl ether cleavage was responsible for the improved bleachability. Preliminary research involving a lignin model compound and commercial birch xylan showed that lignin-carbohydrate condensation products were generated under SAQ cooking conditions. Furthermore, a fraction of these lignin-carbohydrate moieties were subsequently cleaved by acidolysis at pH 2.5 and 105 °C.

Effects of loblolly pine tree age and wood properties on linerboard-grade pulp yield and sheet properties: Part 2

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 41-50
Author(s):  
THOMAS J. MCDONOUGH ◽  
CHARLES E. COURCHENE ◽  
DAVID E. WHITE ◽  
LAURENCE SCHIMLECK ◽  
GARY PETER
Keyword(s):  
Specific Gravity ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Lignin Content ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Tree Age ◽  
Pulp Yield ◽  
Pine Tree ◽  
Old Trees

Results are presented on the relationships among loblolly pine tree age and wood characteristics and the properties of pulp obtained when the trees were chipped and pulped. We selected 13-year-old and 22-year-old loblolly pine trees (18 of each) to represent specified ranges of specific gravity and lignin content. The trees were further characterized by chemical analysis, near infrared (NIR) spectroscopy, and SilviScan analysis of fiber dimensions and properties before being pulped by the kraft process. Handsheets formed from the resulting pulps were characterized in terms of sheet properties that are important for linerboard grades. Multiple regression analysis was then used to identify wood characteristics that most influenced sheet properties and to derive equations relating sheet properties to tree age, specific gravity, and chemical composition. We also developed calibrations so that sheet properties could be predicted from NIR spectroscopic analysis of wood. Nearly all differences in properties of pulps made from 13- and 22-year-old trees were attributable to differences in fundamental wood properties. Sheet properties could be estimated by measuring their near NIR spectra.

scholarly journals Wood and Pulping Properties Variation of Acacia crassicarpa A.Cunn. ex Benth. and Sampling Strategies for Accurate Phenotyping

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1043 ◽  
Author(s):  
Gustavo Salgado Martins ◽  
Muhammad Yuliarto ◽  
Rudine Antes ◽  
Sabki ◽  
Agung Prasetyo ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Basic Density ◽  
Wood Properties ◽  
Tree Level ◽  
Pulp Yield ◽  
Sampling Strategies ◽  
Glucose Content ◽  
Acacia Crassicarpa ◽  
G Ratio ◽  
Whole Tree

Research Highlights: This study provides a comprehensive set of wood and pulping properties of Acacia crassicarpa A.Cunn. ex Benth. to assess variation and efficient sampling strategies for whole-tree level phenotyping. Background and Objectives: A. crassicarpa is an important tree species in Southeast Asia, with limited knowledge about its wood properties. The objective of this study was to characterize important wood properties and pulping performance of improved germplasm of the species. Furthermore, we investigated within-tree patterns of variation and evaluated the efficiency of phenotyping strategies. Materials and Methods: Second-generation progeny trials were studied, where forty 50-month-old trees were selected for destructive sampling and assessed for wood density, kraft pulp yield, α-cellulose, carbohydrate composition, and lignin content and composition (S/G ratio). We estimated the phenotypic correlations among traits determined within-tree longitudinal variation and its importance for whole-tree level phenotyping. Results: The mean whole-tree disc basic density was 481 kg/m3, and the screened kraft pulp yield was 53.8%. The reliabilities of each sampling position to predict whole-tree properties varied with different traits. For basic density, pulp yield, and glucose content, the ground-level sampling could reliably predict the whole-tree property. With near infrared reflectance spectroscopy predictions as an indirect measurement method for disc basic density, we verified reduced reliability values for breast height sampling but sufficiently correlated to allow accurate ranking and efficient selection of genotypes in a breeding program context. Conclusions: We demonstrated the quality of A. crassicarpa as a wood source for the pulping industry. The wood and pulping traits have high levels of phenotypic variation, and standing tree sampling strategies can be performed for both ranking and high-accuracy phenotyping purposes.

Enzymatic bleaching of eucalyptus kraft pulp: effects on the prebleaching filtrate, pulp quality and paper properties

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Maria Tereza Borges ◽  
Claudio Mudado Silva ◽  
Jorge Luiz Colodette ◽  
Rubens Chaves de Oliveira ◽  
Flavio Tesser
Keyword(s):  
Physical Properties ◽  
Kraft Pulp ◽  
Oxygen Demand ◽  
Kappa Number ◽  
Pulp Yield ◽  
Paper Properties ◽  
Eucalyptus Kraft Pulp ◽  
Mechanical And Physical Properties ◽  
Hexenuronic Acid

Abstract Enzymatic bleaching appears to be a promising approach for clean bleaching processes and the reduction of bleaching chemical consumption. In this work, the quality of the filtrates and the pulps has been characterized after enzymatic prebleaching stages of eucalyptus kraft pulp. Four different conditions with xylanase were investigated. Following each prebleaching stage, the properties of the pulp [kappa number, brightness, content of hexenuronic acid (HexA), xylan removal, and pulp yield lost], and of the resulting effluents (chemical oxygen demand (COD), biochemical oxygen demand (BOD), color, and conductivity) were determined. In addition, a complete bleaching sequence was performed to characterize the pulp quality at the end of the sequence. Finally, the pulp was refined in a PFI mill, and the mechanical and physical properties of the resulting paper were determined. The best pulp quality was achieved at pH 7, at which a lower kappa number, higher pulp brightness, and smaller amount of HexA were observed. Under this condition, however, a larger yield loss and a higher effluent COD load had to be accepted. After the complete bleaching sequence, the enzymatic treatments yielded pulps with higher brightness and viscosity as well as with a lower kappa number. The enzymatic treatments resulted in small changes in the mechanical and physical properties of the paper handsheets produced.

scholarly journals Mapping and modeling within-tree variation for loblolly pine pulp yield and lignin content

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Laurence R. Schimleck ◽  
Finto Antony ◽  
Christian Mora ◽  
Joseph Dahlen
Keyword(s):  
Loblolly Pine ◽  
Lignin Content ◽  
Microfibril Angle ◽  
Tree Height ◽  
Wood Properties ◽  
Model Systems ◽  
Growth And Yield ◽  
Pulp Yield ◽  
Yield Increase ◽  
Prediction Systems

AbstractWe examined the within-tree variation of pulp yield and lignin content for loblolly pine (Pinus taeda L.) trees aged 13 and 22 years. Radial trends in pulp yield (increase) and lignin (decrease) were consistent with what would be expected for loblolly pine as were changes in properties related to maturation. Maps, based on the average of 18 trees at each age, depicting pulp yield variation within-tree were similar to loblolly pine maps reported for microfibril angle and stiffness, while lignin maps resembled the inverse of those reported for density and related properties. Mixed-effects models for both properties were developed with the base model for pulp yield explaining 64% of the observed variation, with the inclusion of tree height improving the model slightly, whereas models for lignin content explained 44% of the variability. The models could be incorporated into growth and yield prediction systems, or procurement model systems that predict within-tree wood properties based on age and tree size.

scholarly journals An Approach for Feedforward Model Predictive Control of Continuous Pulp Digesters

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 602 ◽  
Author(s):  
Rahman ◽  
Avelin ◽  
Kyprianidis
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Near Infrared ◽  
Lignin Content ◽  
Wood Properties ◽  
Kappa Number ◽  
Industrial Control ◽  
Paper Mills ◽  
Predictive Controller ◽  
Pulp Digesters

Kappa number variability at the continuous digester outlet is a major concern for pulp and paper mills. It is evident that the aforementioned variability is strongly linked to the feedstock wood properties, particularly lignin content. Online measurement of lignin content utilizing near-infrared spectroscopy at the inlet of the digester is paving the way for tighter control of the blow-line Kappa number. In this paper, an innovative approach of feedforwarding the lignin content to a model predictive controller was investigated with the help of modeling and simulation studies. For this purpose, a physics-based modeling library for continuous pulp digesters was developed and validated. Finally, model predictive control approaches with and without feedforwarding the lignin measurement were evaluated against current industrial control and proportional-integral-derivative (PID) schemes.

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