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.

Brownstock washing: A review of the literature

TAPPI Journal ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 9-19 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART
Keyword(s):  
High Efficiency ◽  
Black Liquor ◽  
Material Balance ◽  
Kraft Pulping ◽  
Wash Water ◽  
Pulp Fibers ◽  
Kraft Process ◽  
Cooking Process ◽  
Materials Used ◽  
Entrapped Air

Brownstock washing is a complex, dynamic process in which dirty wash water or weak black liquor (dissolved organic and inorganic material obtained from the pulp cooking process) is separated from pulp fibers. The use of material balance techniques is of great importance to identify potential problems and determine how well the system is operating. The kraft pulping industry was the first known to combine pulp washing with the recovery of materials used and produced in the wood cooking process. The motivation behind materials recovery is economic, and more recently, environmentally driven. The chemicals used in the kraft process are expensive as compared to those used in the sulfite process. For the kraft process to be economically viable, it is imperative that a very high percentage of the cooking chemicals be recovered. To reach such high efficiency, a variety of washing systems and monitoring parameters have been developed. Antifoam additives and processing aids have also played an important role in increasing washing effectiveness. Antifoam materials help attain washing effectiveness by preventing entrapped air from forming in the system, which allows for an easier, unimpeded flow of filtrate through the screens and washers.

Kraft Pulping and Specific Gravity in the Uppermost Stem of Fertilized Balsam Fir

1975 ◽  
Vol 5 (3) ◽  
pp. 399-402 ◽  
Author(s):  
J. D. Gagnon ◽  
K. Hunt
Keyword(s):  
Specific Gravity ◽  
Boreal Forest ◽  
Kraft Pulping ◽  
Balsam Fir ◽  
Pulp Yield ◽  
Kraft Process ◽  
Forest Region ◽  
The Mean ◽  
Boreal Forest Region

Samples of five pairs of fertilized and non-fertilized 60-year-old natural balsam fir (Abiesbalsamea (L.) Mill.) growing in the Quebec boreal forest region were pulped by the kraft process and the specific gravity was measured. Analyses carried out 7 years after treatment on the last seven terminal internodes revealed the mean pulp yield of trees fertilized exceeded that of non-fertilized by 7%, while the mean specific gravity was about 6% lower.

scholarly journals Increasing Softwood Pulp Yield by Minimizing Primary Peeling of Wood Carbohydrates Using Sodium Methyl Mercaptide Before and During Kraft Pulping

2021 ◽  
Author(s):  
Ravikant A Patil ◽  
van Heiningen Adriaan
Keyword(s):  
Treatment Temperature ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Yield Increase ◽  
Sodium Methyl ◽  
White Liquor ◽  
Softwood Pulp ◽  
Dry Wood ◽  
Pre Treatment ◽  
Co Addition

Abstract The objective of this work was to determine the effect of sodium methyl mercaptide (SMM) on the minimization of peeling reactions of southern pine chips in the kraft pulping process. Two methods were evaluated for SMM addition to the pulping process: 1) pre-treatment before pulping or 2) co-addition with white liquor. The effect of SMM charge, pre-treatment temperature and time, and pH of pre-treatment liquor was studied. The experimental results showed about 1.5 to 2.5 % (on O.D. (oven dry) wood basis) increase in the pulp yield after pre-treatment with or co-addition of 4.38% SMM (on O.D. wood basis). The use of 4.38% SMM allowed a decrease of the white liquor effective alkali charge (EA, on O.D. wood basis) by 3%. 4.38% SMM charge seemed to be optimum for the pre-treatment. Pre-treatment at lower pH resulted in a significant decrease in yield and an increase in rejects. The increase in pulp yield was mostly due to the increased retention of cellulose and xylan. The retention of galactoglucomannan was negligible. About 80% of the cellulose yield increase is due to the suppression of primary peeling. The remainder (0.3–0.4% of the yield increase (on O.D. wood basis) is due to reduced alkaline hydrolysis and subsequent secondary peeling.

scholarly journals MEA-conversion of agro-wastes to paper-pulp: Optimization of pulping conditions

2021 ◽  
Vol 11 (2) ◽  
pp. 337-349
Author(s):  
Henry O Chibudike ◽  
Nelly A Ndukwe ◽  
Eunice C Chibudike ◽  
Olubamike A Adeyoju ◽  
Nkemdilim I Obi
Keyword(s):  
Negative Impact ◽  
Black Liquor ◽  
Cooking Time ◽  
Experimental Result ◽  
High Yield ◽  
Pulp Yield ◽  
Subsequent Paper ◽  
Sulphur Compounds ◽  
Fixed Temperature ◽  
Cellulosic Pulp

This paper investigates the potentials of a novel environmental friendly pulping (Monoethanoleamine-MEA) process in comparison with conventional Soda and Kraft pulping processes in furnishing high yield pulp from agro-biomass for the formation Papers and other paper products. The pulping investigation had three (3) factors at three (3) different levels each: Factor 1, MEA concentration (50, 75 and 100%); Factor 2, cooking time (60, 90 and 120minutes); Factor 3, liquor-biomass ratio (4, 6 and 8) at a fixed temperature of 123±5oC. Consequently, the experimental design had 27 treatments (3×3×3) and 2 replicates. By using a central composite factorial design, equations relating the dependent variable (pulp yield) to the different independent variables (cooking temperature, cooking time and liquor concentration) were derived; reproducing the experimental result for the dependent variable with errors less than 15%. Models were evaluated to analyze the effect of experimental pulping conditions on pulp properties and evaluate the effect of these properties on furnished paper samples. Pulp Screened Yields was in the range of 42.45 to 49.18% calculated on oven dry (O.D) basis. The resultant pulps obtained from the cooking operation had very good appearance, exhibiting fairly bright color, with slow tendency to felt, thereby making drainage and consequent paper making time short. It is recommended that the cellulosic pulp obtained from MEA pulping of EFB is appropriate as virgin fiber for strengthening secondary fibers in recycled papers and also for developing certain types of writing, printing and packaging paper materials. Conclusive investigation on EFB fiber in this research study asserts that it has a promising future (when used in blend with certain long fiber plant i.e. kenaf) in substituting wood in the pulp, paper and fiber- board industry. Conclusive investigation also asserts from over-all parameter achieved that monoethanolamine-MEA when used as the main de-lignifying agent furnished pulp and subsequent paper with good strength properties that can adequately match those from conventional (i.e. kraft and soda) processes and because it works without the use of sulphur compounds, it attributes a particular benefit of simple MEA recovery by distillation, allowing black liquor combustion to be dispensed and the dissolved lignin recovered without negative impact on the environment.

scholarly journals DESAIN EKSPERIMENTAL FAKTORIAL UNTUK PENENTUAN FAKTOR PALING BERPENGARUH PADA PROSES PULPING ORGANOSOLV BERBAHAN BAKU LIMBAH DAUN NANAS

2020 ◽  
Vol 20 (4) ◽  
pp. 120-124
Author(s):  
Glenn Mochamad Rayhan ◽  
Salsabila Fachrina ◽  
Rizka Amalia
Keyword(s):  
Lignin Content ◽  
Black Liquor ◽  
Influential Factors ◽  
Cooking Time ◽  
Operating Conditions ◽  
Influential Factor ◽  
Raw Material ◽  
Pulp Yield ◽  
Cellulose Content ◽  
Organosolv Pulping

Paper production has been identified with industries that destroy forests (deforestation). Utilizing alternative wood substitute raw materials, such as pineapple leaves can be one solution to the problem. Pineapple plants can produce more than 70 leaves with cellulose content in the leaves which reaches 69.5-71.5%, so it has the potential to be used as raw material for paper. The organosolv process was chosen as a pulp manufacturing process because it produces high purity in the byproducts (lignin and hemicellulose), high pulp yield, easy recovery of black liquor and no sulfur element, making it safer for the environment. This study aims to determine the most influential factors in the organosolv pulping process with a factorial experimental design method 23. Variables used include solvent types (ethanol and acetic acid), pulp cooking time (60 minutes and 110 minutes) and types of leaf dryness (wet leaves) and dried leaves). From the results of the analysis, the most influential factor in the organosolv pulping process is the type of solvent (ethanol). Optimal operating conditions were obtained for solvent ethanol, cooking time of 60 minutes with wet leaves, where cellulose content was 96.31% and lignin content decreased by 17.80% in dry pulp.

Kinetic Study on Lignin Extraction by Ionic Liquid

2013 ◽  
Vol 864-867 ◽  
pp. 477-481
Author(s):  
Yu Deng ◽  
Zhi Min Zhang
Keyword(s):  
Atmospheric Pressure ◽  
Black Liquor ◽  
Order Reaction ◽  
Pulp Yield ◽  
Residual Lignin ◽  
Yield Increase ◽  
First Order ◽  
Lignin Removal ◽  
Lignin Extraction ◽  
Cooking Temperature

This paper has studied the dynamics of delignification in ionic liquids pulping for straw at atmospheric pressure. The date showed that the concentration of the residual lignin in the pulp obviously decreased with the extension of steaming time, pulp yield increase, and the hexose and pentose content in the black liquor was gradually increasing, and at the same time, the amount of the hexose was higher than the pentyl. The concentration of the residual lignin reduced gradually with the cooking temperature increased,the pulp yield increase slowly. The lignin removal reaction is first order reaction, the activation energy is 42.117kJ/mol.

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.

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

Polysulfide-borohydride modification of southern pine alkaline pulping integrated with hydrothermal pre-extraction of hemicelluloses

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 9-16
Author(s):  
SUNG-HOON YOON ◽  
HARRY CULLINAN ◽  
GOPAL A. KRISHNAGOPALAN
Keyword(s):  
Loblolly Pine ◽  
Sodium Borohydride ◽  
Kraft Pulping ◽  
Hot Water ◽  
Pulp Yield ◽  
Paper Strength ◽  
Southern Pine ◽  
Two Stage ◽  
Simultaneous Treatment ◽  
Process Modification

We studied three process modifications to investigate their effects on the property and yield recovery capabilities of kraft pulping integrated with hemicellulose pre-extraction of southern pine. Loblolly pine chips were pre-extracted with hot water until the sugar extraction yield reached the targeted value of 10% and then subjected to conventional and modified kraft pulping. Modification included polysulfide pretreatment; polysulfide-sodium borohydride dual pretreatment, and polysulfide followed by polysulfide-sodium borohydride dual pretreatment two-stage pretreatments prior to kraft pulping. In the first modification, about 5% of the lost pulp yield (total 7%) caused by hemicellulose pre-extraction could be recovered with 15%-20% polysulfide pretreatment. Complete recovery (7%) was achieved with simultaneous pretreatment using 15% polysulfide and 0.5% sodium borohydride with 0.1% anthraquinone in polysulfide-sodium borohydride dual pretreatment. Two-stage pretreatment using recycled 15% polysulfide followed by simultaneous treatment of 6% polysulfide and 0.4%–0.5% sodium borohydride with 0.1% anthraquinone also achieved 100% yield recovery. Continuous recycling of 15% polysulfide employed in the two-stage process modification maintained its yield protection efficiency in a repeated recycling cycle. No significant changes in paper strength were found in handsheets prepared from the three process modifications, except for a minor reduction in tear strength.

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