Lignin carbohydrate complex studies during kraft pulping for producing paper grade pulp from birch

TAPPI Journal ◽  
2020 ◽  
Vol 19 (9) ◽  
pp. 447-460
Author(s):  
RAGHU DESHPANDE ◽  
LARS SUNDVALL ◽  
HANS GRUNDBERG ◽  
MARTIN LAWOKO ◽  
GUNNAR HENRIKSSON
Keyword(s):  
Raw Materials ◽  
Kraft Pulping ◽  
Birch Wood ◽  
Oxygen Delignification ◽  
Covalent Bonds ◽  
Chemical Treatments ◽  
Kraft Process ◽  
Carbohydrate Complex ◽  
Chemical Pulping ◽  
Pulp Production

Paper grade pulp production across the globe is dominated by the kraft process using different lignocellulosic raw materials. Delignification is achieved around 90% using different chemical treatments. A bottleneck for complete delignification is the presence of residual covalent bonds that prevail between lignin and carbohydrate even after severe chemical pulping and oxygen delignification steps. Different covalent bonds are present in native wood that sustain drastic pulping conditions. In this study, 100% birch wood was used for producing paper grade pulp, and the lignin carbohydrate bonds were analyzed at different stages of the kraft cook. The lignin carbohydrate bonds that were responsible for residual lignin retention in unbleached pulp were compared and analyzed with the original lignin-carbohydrate complex (LCC) bonds in native birch wood. It was shown that lignin remaining after pulping and oxygen delignification was mainly bound to xylan, whereas the lignin bound to glucomannan was for the most part degraded.

scholarly journals Technological evaluation of Pinus maximinoi wood for industrial use in kraft pulp production

TAPPI Journal ◽  
2021 ◽  
Vol 20 (8) ◽  
pp. 501-508
Author(s):  
MARINA ULIAN COELHO ◽  
FRANCIDES GOMES DA SILVA, JR. ◽  
FLAVIANA REIS MILAGRES ◽  
SILVANA MEISTER SOMMER ◽  
CARLOS AUGUSTO SOARES DO AMARAL ◽  
...  
Keyword(s):  
Process Analysis ◽  
Black Liquor ◽  
Basic Density ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Bulk Property ◽  
Oxygen Delignification ◽  
Old Trees ◽  
Pulp Production

This study characterized Pinus maximinoi wood and evaluated its performance for pulp production. Samples of Pinus taeda wood were used as reference material. For both species, wood chips from 14-year-old trees were used for the technological characterization, pulping, bleaching process analysis, and pulp properties. A modified kraft pulping process was carried out targeting kappa number 28±5% on brownstock pulp. The bleaching sequence was applied for bleached pulp with final brightness of 87±1 % ISO. Refinability and resistance properties were measured in the bleached pulps. Compared to P. taeda wood, P. maximinoi showed slightly higher basic density (0.399 g/cm³) and higher holocellulose (64.5%), lignin (31.1%), and extractives content (4.5%), along with lower ash content (0.16%). P. maximinoi tracheids showed greater wall thickness (6.4 µm) when compared to P. taeda tracheids. For the same kappa number, P. maximinoi and P. taeda resulted in similar screened yield, with an advantage observed for P. maximinoi, which resulted in lower specific wood consumption (5.281 m³/o.d. metric ton), and lower black liquor solids (1.613 metric tons/o.d. metric ton). After oxygen delignification, P. maximinoi pulp showed higher efficiency on kappa reduction (67.2%) and similar bleaching chemical demand as P. taeda pulp. Compared to P. taeda pulps, the refined P. maximinoi pulps had similar results and the bulk property was 10% higher. Results showed that P. maximinoi is an interesting alternative raw material for softwood pulp production in Brazil.

Selectivity of oxygen delignification for southern softwood kraft pulps with high lignin content

TAPPI Journal ◽  
2011 ◽  
Vol 10 (8) ◽  
pp. 29-39 ◽  
Author(s):  
LI TAO ◽  
JOSEPH M. GENCO ◽  
BARBARA J.W. COLE ◽  
RAYMOND C. FORT
Keyword(s):  
Hydroxyl Radicals ◽  
Lignin Content ◽  
Degree Of Polymerization ◽  
Kraft Pulping ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Kraft Process ◽  
Carbohydrate Degradation ◽  
Polymeric Chains ◽  
High Lignin Content

The selectivity of kraft pulping versus the oxygen delignification processes over the range of kappa nos. 25–90 was compared. Kraft pulping was found to be more selective than oxygen delignification for removing lignin from southern softwood kraft pulps. The greater selectivity is thought to be related to hydroxyl radicals that form in the oxygen delignification process that are not present in the kraft process. The hydroxyl radicals attack the carbohydrates and randomly cleave the polymeric chains, causing a significant decrease in the degree of carbohydrate polymerization and thus a loss of viscosity. Kraft pulping generates hydrosulfide ions that are highly selective and attack the lignin. Carbohydrate degradation occurs mainly from peeling reactions, which do not appreciably reduce the degree of polymerization of the cellulose and thus there is less viscosity loss. At low lignin content (i.e., low kappa number), the remaining lignin is likely bound covalently to the carbohydrate portion in both processes. Therefore, removal of the lignin results in significant degradation of the carbohydrates.

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.

scholarly journals Odor and Constituent Odorants of HDPE–Lignin Blends of Different Lignin Origin

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 206
Author(s):  
Bianca Lok ◽  
Gunnar Mueller ◽  
Johannes Ganster ◽  
Jens Erdmann ◽  
Andrea Buettner ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Raw Materials ◽  
Mineral Oil ◽  
Raw Material ◽  
Systematic Evaluation ◽  
Natural Polymers ◽  
Kraft Process ◽  
Global Demand ◽  
Reduction Strategies ◽  
Soda Lignin

The still-rising global demand for plastics warrants the substitution of non-renewable mineral oil-based resources with natural products as a decisive step towards sustainability. Lignin is one of the most abundant natural polymers and represents an ideal but hitherto highly underutilized raw material to replace petroleum-based resources. In particular, the use of lignin composites, especially polyolefin–lignin blends, is currently on the rise. In addition to specific mechanical property requirements, a challenge of implementing these alternative polymers is their heavy odor load. This is especially relevant for lignin, which exhibits an intrinsic odor that limits its use as an ingredient in blends intended for high quality applications. The present study addressed this issue by undertaking a systematic evaluation of the odor properties and constituent odorants of commercially available lignins and related high-density polyethylene (HDPE) blends. The potent odors of the investigated samples could be attributed to the presence of 71 individual odorous constituents that originated primarily from the structurally complex lignin. The majority of them was assignable to six main substance classes: carboxylic acids, aldehydes, phenols, furan compounds, alkylated 2-cyclopenten-1-ones, and sulfur compounds. The odors were strongly related to both the lignin raw materials and the different processes of their extraction, while the production of the blends had a lower but also significant influence. Especially the investigated soda lignin with hay- and honey-like odors was highly different in its odorant composition compared to lignins resulting from the sulfurous kraft process predominantly characterized by smoky and burnt odors. These observations highlight the importance of sufficient purification of the lignin raw material and the need for odor abatement procedures during the compounding process. The molecular elucidation of the odorants causing the strong odor represents an important procedure to develop odor reduction strategies.

scholarly journals WOOD COMPONENTS AS SOURCES OF PENTO-CONTAINING RAW MATERIALS FOR SYNTHESIS OF USEFUL COMPOUNDS, PRODUCTS AND REAGENTS

2021 ◽  
Vol 64 (3) ◽  
pp. 107-115
Author(s):  
Irina A. Chetvertneva ◽  
Oleg Kh. Karimov ◽  
Galina A. Teptereva ◽  
Natalia S. Tivas ◽  
Eldar M. Movsumzade ◽  
...  
Keyword(s):  
Raw Materials ◽  
Condensation Reaction ◽  
Agricultural Waste ◽  
Monomer Unit ◽  
Paper Industry ◽  
Raw Material ◽  
Chemical Transformations ◽  
Covalent Bonds ◽  
Industry Waste ◽  
Wood Processing

The paper considers the main components and products of wood processing, agricultural waste, pulp and paper industry waste and qualifies them as sources of pentose-containing resource-renewable domestic raw materials. The article describes in detail the structural components of wood as a natural polymer, which contains aromatic and carbohydrate parts. It is noted that these poly-mers are promising as raw materials for the production of useful chemical products. The role of lignin, cellolose and hemicellulose in the design of mechanical and structural properties of wood is considered. The article considers the features of the sulfonation reactions of the lignin monomer unit depending on the pH of the medium: acidic, neutral and alkaline. There are three main reac-tions that occur simultaneously with lignin in the process of wood delignification during sulfite cooking, such as the sulfonation reaction, the hydrolytic destruction reaction, and the condensation reaction. It is shown that the lignin-hemicellulose matrix contains three types of interconnected mesh structures: the lignin itself; a network of covalent bonds of lignin with hemicelluloses, and a network whose structure is obtained due to the hydrogen bond and the forces of the physical inter-action of lignin and hemicelluloses. The features of chemical transformations of the monomeric aromatic link of lignosulfonate – phenylpropane unit in the processes of wood delignification, the main chemical reactions of wood raw material delignification under the conditions of sulfite and neutral-sulfite brews are shown. The method of quantitative determination of monosaccharides in the composition of the carbohydrate part is proposed.

scholarly journals Prospects for the use of protein-carbohydrate complex based on mung bean seeds in the functional meat products technology

2020 ◽  
Vol 175 ◽  
pp. 08004 ◽  
Author(s):  
Andrey Alexeev ◽  
Tatyana Alexeeva ◽  
Larisa Enaleva ◽  
Tatyana Tupolskikh ◽  
Nataliia Shumskaia
Keyword(s):  
Mung Bean ◽  
Raw Materials ◽  
Meat Products ◽  
First Grade ◽  
Biologically Active ◽  
Plant Materials ◽  
Biological Value ◽  
Functional Additives ◽  
Carbohydrate Complex ◽  
Germinated Seeds

The use of new non-traditional types of plant materials in the diet is one of the ways to improve the meat products’ quality. The combination of plant proteins with animals creates biologically active amino-acid complexes which increase its bioavailability for organism and biological value of the product. In this case, the use of non-traditional plant materials in the production technology of new types of sausage products to improve the quality of the end product is prospective and relevant. Research objective is development of formulations and technologies for new types of high biological value products, based on combination of meat raw materials with functional additives of plant origin. The work was performed at the Department of Food Technology FSBEI HE «Don State Agrarian University», Persianovsky, Rostov region. The objects of research were the new protein-carbohydrate complexes based on flour from germinated seeds of mung bean, control and model forcemeat based on trim beef of first grade, lean trim pork and mid fat trim pork, and end products. Introduction to the cooked sausage products formulation of mung bean germinated seeds flour has a beneficial effect on the organoleptic properties of the end product and enriches it with biologically valuable substances.

Chemical pulping: Evaluation of rubber wood (Hevea brasiliensis) as a raw material for kraft pulping

2011 ◽  
Vol 26 (3) ◽  
pp. 258-262 ◽  
Author(s):  
M. Sarwar Jahan ◽  
M. M. Haider ◽  
Mostafizur Rahman ◽  
D. Biswas ◽  
M. Misbahuddin
Keyword(s):  
Hevea Brasiliensis ◽  
Kraft Pulping ◽  
Raw Material ◽  
Rubber Wood ◽  
Chemical Pulping

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.

MgSO4 vs. Mg(OH)2 as a cellulose protector in oxygen delignification

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Jean Bouchard ◽  
Jie Wang ◽  
Richard Berry
Keyword(s):  
Calcium Concentration ◽  
Lower Cost ◽  
Iron Concentration ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Major Mechanism ◽  
Carbohydrate Complex ◽  
Magnesium Compound ◽  
Unbleached Pulp

Abstract It has been proposed that magnesium hydroxide can replace magnesium sulfate as a lower cost cellulose protector. This claim has been evaluated based on four commercial unbleached softwood kraft pulps. The selectivity was improved in the presence of soluble MgSO4, but little or no selectivity improvement was obtained when insoluble Mg(OH)2 was applied. It was further observed that in-situ iron concentration in unbleached pulp affects selectivity of oxygen delignification, while in-situ calcium concentration affects efficiency of magnesium protection. The results favor the hypothesis of formation of a Mg-carbohydrate complex as the major mechanism of cellulose protection by magnesium. The application of a soluble magnesium compound is recommended to improve selectivity in oxygen delignification.

Study on Preparation of Dissolving Grade Pulp and its Kinetics of Prehydrolysis

2011 ◽  
Vol 233-235 ◽  
pp. 1479-1484
Author(s):  
Ke Xin Hu ◽  
Guang Ming Zeng ◽  
Hai Chao Zhang
Keyword(s):  
Quality Standards ◽  
Kraft Pulping ◽  
Cooking Time ◽  
Bleaching Process ◽  
First Order ◽  
Pseudo First Order ◽  
P Factor ◽  
Prehydrolysis Kraft ◽  
Kinetics Of ◽  
Pulp Production

The possibilities of dissolving grade pulp production from reed were investigated in this paper. Two – stage prehydrolysis – kraft pulping and CEHA bleaching process of reed for preparation of dissolving grade pulp were studied in laboratory. The optimum cooking and bleaching conditions were found out. The mechanism and its kinetics of reed in prehydrolysis process were also discussed. The results showed that under the laboratory conditions the rate for removal of materials at about 175°C follow approximately a pseudo first order law with two distinct phrases: the bulk removal and the residual removal of the materials. The prehydrolysis-factor (P-factor) was established. The advantage of using P-factor is predict compensating adjustments in cooking time and/or temperature to give the same degree of pulping and to produce pulp with predetermined characteristics. It is found that three distinct delignification rate stages about 75% of pentosans and about 50% of lignin were removed. A CEHA four stage bleaching is used for dissolving grade pulp. Total chlorine charge in bleaching is 6% (to oven-dry pulp). The results show that all of the indices fitted the quality standards of dissolving grade pulp.

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