Kraft Pulping of Young Trembling Aspen from Manitoba

1973 ◽  
Vol 3 (3) ◽  
pp. 359-366 ◽  
Author(s):  
I. E. Bella ◽  
K. Hunt
Keyword(s):  
Specific Gravity ◽  
Kraft Pulp ◽  
Gravity Data ◽  
Tree Height ◽  
Kraft Pulping ◽  
Trembling Aspen ◽  
Softwood Pulp ◽  
Breaking Length ◽  
Pulp Strength

The unscreened kraft pulp yields at permanganate No. 14 for 7-, 13-, and 22-year-old trembling aspen (Populustremuloides Michx.) trees from Manitoba for effective alkali applications of 14% were 56.2, 55.7, and 54.8% (o.d. wood), respectively. Specific gravity data for green and ovendry wood are presented, but no relationship with tree height could be established. Pulp strength values from the 7-, 13-, and 22-year-old aspen were, respectively, 60, 67, and 65 for tear factor; 67, 71, and 72 for burst factor; and 10.1, 10.4, and 10.7 (km) for breaking length, respectively. These data indicate that trees of any of the three ages will make a kraft pulp comparable in yield and strength to commercial hardwood–softwood pulp.

Kraft-pulping evaluation of decayed trembling aspen (Populustremuloides) from Ontario

1978 ◽  
Vol 8 (2) ◽  
pp. 181-187 ◽  
Author(s):  
K. Hunt ◽  
J. T. Basham ◽  
J. A. Kemperman
Keyword(s):  
Kraft Pulping ◽  
Decayed Wood ◽  
Trembling Aspen ◽  
Average Decrease ◽  
Central Canada ◽  
Breaking Length

Kraft-pulping data of sound and decayed trembling aspen (Populustremuloides Michx.) samples from five clones in Ontario are reported. From each clone, samples consisted of one sound bolt and three bolts from each of three major types of stem decay of aspen in central Canada, caused by Fomesigniarius (L. ex Fr.) Kichx., Radulumcasearium (Morg.) Lloyd, and Peniophorapolygonia (Pers. ex Fr.) Bourd.Average yields for sound and decayed woods were 57.5 and 51.9% ovendry wood, respectively; equivalent to an average decrease of 9.7% ovendry pulp due to decay. A decrease of 11.5% was obtained when only advanced decays were considered.Screen rejects were greater for both sound and decayed wood than in previous studies, even at low permanganate numbers. They appeared to be dependent on the type of decay.Pulp strengths from incipient-decayed wood differed little from those of sound wood, but those from the advance-decayed wood showed substantial decreases. Tear factor was the most affected (20–29% lower), and breaking length least affected, by decay (13–9% lower).

Comparison between Green Liquor Pretreatment-Kraft Pulping and Conventional Kraft Pulping

2013 ◽  
Vol 781-784 ◽  
pp. 2650-2653
Author(s):  
Zhang Hong Xie ◽  
Jing Hui Zhou ◽  
Hai Ming Li ◽  
Guang Wei Sun
Keyword(s):  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Green Liquor ◽  
Pulp Strength

This paper studied the differences of pulping performances, beating characteristics and strength properties between green liquor pretreatment-Kraft pulping and conventional Kraft pulping based on previous optimized pulping conditions. The green liquor pretreatment-Kraft pulping has higher yield, lower Kappa number, reduced residual effective alkali and decreased viscosity. Green liquor pretreatment improves pulp strength properties although green liquor pretreatment-Kraft pulp has beating characteristics similar to conventional Kraft pulp.

TCF Short-Sequence Bleaching of Pinus Kesiya Pulp Made by Low-Temperature Kraft Pulping

2011 ◽  
Vol 396-398 ◽  
pp. 2188-2192
Author(s):  
Yang Chen ◽  
Jie He ◽  
Heng Zhang
Keyword(s):  
Low Temperature ◽  
Kraft Pulp ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Short Sequence ◽  
Pinus Kesiya ◽  
Bleaching Condition ◽  
Folding Endurance ◽  
Breaking Length ◽  
Pulp Properties

In this paper, the TCF short-sequence bleaching (OQPaP) of pinus kesiya pulp from low-temperature kraft pulping with kappa number of 21.32 and viscosity of 1194mL•g-1 (the maximum pulping temperature was only 150°C) was optimized. Under the optimum bleaching condition, the bleached pulp properties of low-temperature kraft pulp were as follows: yield 93.1%, brightness 85.31% ISO, kappa number 1.02, viscosity 751mL•g-1 and PC number 0.28. And physical properties of handsheet (after beating to 45oSR) were as follows: breaking length 5.41km, bursting index 3.48kPa•m2•g-1, tearing index 8.4mN•m2•g-1, and folding endurance 146 times.

Fate of phosphorus in the recovery cycle of the kraft pulping process

TAPPI Journal ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 139-148
Author(s):  
MARYAM SADEGH MOUSAVI ◽  
NIKOLAI DEMARTINI
Keyword(s):  
Kraft Pulp ◽  
Pulp Mill ◽  
Field Studies ◽  
Kraft Pulping ◽  
Pulp Mills ◽  
Recovery Cycle ◽  
Green Liquor ◽  
Green Liquor Dregs ◽  
Kraft Pulp Mills ◽  
Negative Effect

The accumulation of nonprocess elements in the recovery cycle is a common problem for kraft pulp mills trying to reduce their water closure or to utilize biofuels in their lime kiln. Nonprocess elements such as magne-sium (Mg), manganese (Mn), silicon (Si), aluminum (Al), and phosphorus (P) enter the recovery cycle via wood, make-up chemicals, lime rock, biofuels, and process water. The main purge point for these elements is green liquor dregs and lime mud. If not purged, these elements can cause operational problems for the mill. Phosphorus reacts with calcium oxide (CaO) in the lime during slaking; as a result, part of the lime is unavailable for slaking reactions. The first part of this project, through laboratory work, identified rhenanite (NaCa(PO4)) as the form of P in the lime cycle and showed the negative effect of P on the availability of the lime. The second part of this project involved field studies and performing a mass balance for P at a Canadian kraft pulp mill.

Application of Chelating Agents as Cooking Aids in Bamboo Pulping

2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Strength

The effect of chelating agents Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp yield was 49.52% when DTPMPA dosage is 0.4%, at the same time the Kappa number was lower. With the increasing of DTPMPA dosage in bamboo kraft pulping, the bamboo pulp strength was increased.

scholarly journals Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Chemical Characteristics ◽  
Kraft Pulps ◽  
Opposite Wood ◽  
Alkali Consumption ◽  
Pulp Strength

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.

scholarly journals Estimation of energy efficiency of kraft pulp production with the exergy increment method

2020 ◽  
Vol 22 (2) ◽  
pp. 3-11
Author(s):  
Р. V. Lukanin
Keyword(s):  
Energy Efficiency ◽  
Kraft Pulp ◽  
Black Liquor ◽  
High Energy ◽  
Kraft Pulping ◽  
Flue Gases ◽  
Flow Chart ◽  
Lime Kiln ◽  
System A ◽  
Recovery Boilers

This article contains results of exergic analysis of kraft pulping flow chart. The results of exergic balances of main kraft pulping processes such as alkali recovery at recovery boilers, black liquor evaporation, chips cooking, lime decarbonation are considered in details in the article. The analysis of the process flow chart makes it possible to determine the bottlenecks in the use of heat energy and to substantiate principal lines for increasing energy efficiency of the processes under study. A main share of the exergy expended in the existing pulping process is due to alkali recovery in the recovery boiler and comprises 70% of the total exergy available in the system. A procedure of hydrothermal production of chemicals in the process of kraft pulping is studied. A schematic diagram and analysis of heat technique of the kraft pulping process which in fact consists of organic component removal from black liquor through its autoclave carbonation with flue gases releasing from lime kiln at the temperature 80-90 oC are given in the article. The removal of organic components under these conditions can reach 70 %. In the studied version the exergic efficiency ηe = 80 % is considerably higher than that of the flow chart existing for chemicals recovery which is equal to ηe = 48 %. This is the evidence of high energy efficiency of the method developed.

scholarly journals Single-tree Equations for Estimating Biomass of Trembling Aspen, Large Tooth Aspen and White Birch in Ontario

1981 ◽  
Vol 57 (4) ◽  
pp. 169-173 ◽  
Author(s):  
I. S. Alemdag ◽  
K. W. Horton
Keyword(s):  
New York ◽  
Tree Height ◽  
Stem Bark ◽  
Trembling Aspen ◽  
White Birch ◽  
Stem Wood ◽  
Single Tree ◽  
Breast Height ◽  
Forest Regions ◽  
Whole Tree

Ovendry mass of single trees of trembling aspen, largetooth aspen, and white birch in the Great Lakes — St. Lawrence and Boreal forest regions in Ontario was studied in relation to stem dimensions. Mass equations for tree components based on diameter at breast height outside bark and tree height were developed. Results were found more dependable for stem wood and the whole tree than for stem bark, live branches, and twigs plus leaves. Ovendry mass values were slightly higher than those reported for New York and northern Minnesota.

scholarly journals Pan tropical biomass equations for Mexico's dry forests

2014 ◽  
Vol 32 (3) ◽  
pp. 367-376 ◽  
Author(s):  
José Návar
Keyword(s):  
Specific Gravity ◽  
Stand Structure ◽  
Gravity Data ◽  
Theoretical Models ◽  
Tropical Dry Forests ◽  
Large Sample Size ◽  
Dry Forests ◽  
Wood Specific Gravity ◽  
Spatial Coverage ◽  
Ecological Importance

This study reports a set of robust regional M-tree allometric equations for Mexico's tropical dry forests and their application to a forest inventory dataset for the States of Durango and Sinaloa, Mexico. Calculated M data from 15 reported equations were fitted, applied and validated for regional and global models. Proposed theoretical models, empirically derived equations, as well as global and local reported equations were fitted and applied to calculated M-tree data using wood specific gravity, diameter at breast height, and top height as exogenous variables. Empirically-derived, computer-based equations assessed the M-tree evaluations slightly better than the theoretical, the global and the local models. However, the theoretical models projected compatible M-tree values and deserve further attention once wood specific gravity data are collected in the field. Using the best fit equation, mean M plot density values of 30, 41 and 35 Mg ha-1 were estimated from 57 plots (1,600 m2 each), 217 plots (1,000 m2 each) and 166 plots (1,000 m2 each) in the tropical dry forests of the States of Durango, Tiniaquis and Vado Hondo (Sinaloa), respectively. The large sample size, the richness of the tested allometric models, the economic and ecological importance of this data-source, and the spatial coverage of these equations made this dataset uniquely useful for biomass, charcoal, and other bio-energy estimations, as well as for understanding the inherent heterogeneity of the stand-structure in dynamic tropical forest environments.

Evidence for the formation of lignin-hexenuronic acid-xylan complexes during modified kraft pulping processes

Holzforschung ◽  
2006 ◽  
Vol 60 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Zhi-Hua Jiang ◽  
Jean Bouchard ◽  
Richard Berry
Keyword(s):  
Acid Hydrolysis ◽  
Kraft Pulp ◽  
Kraft Pulping ◽  
Order Kinetic ◽  
Kraft Pulps ◽  
First Order ◽  
Pseudo First Order ◽  
Hexenuronic Acid ◽  
Kinetics Of ◽  
Hydrolysis Of

Abstract The finding that hexenuronic acid (HexA) groups can be selectively removed from kraft pulps by acid hydrolysis has provided an opportunity to reduce bleaching chemicals. However, there is evidence that the acid hydrolysis is not uniform. In this report, we evaluate the kinetics of acid hydrolysis of HexA in a xylan sample enriched with HexA, a conventional kraft pulp, and three modified kraft pulps: anthraquinone pulp (Kraft-AQ), polysulfide pulp (PS), and polysulfide-anthraquinone pulp (PS-AQ). We found that HexA present in the xylan and conventional kraft pulp behaved similarly toward the acid hydrolysis throughout. On the other hand, HexA present in the Kraft-AQ, PS-AQ and PS pulps was heterogeneous toward acid hydrolysis and the reaction can be separated into two pseudo-first-order kinetic phases, each of which has a different rate constant. The kinetic data provide evidence for the formation of lignin-HexA-xylan complexes during modified kraft pulping processes.

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