Relevant bibliographies by topics / Wood delignification / Journal articles

To see the other types of publications on this topic, follow the link: Wood delignification.

Journal articles on the topic 'Wood delignification'

Author: Grafiati

Published: 7 September 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Wood delignification.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

Adaskaveg, James E., and Robert L. Gilbertson. "In vitro decay studies of selective delignification and simultaneous decay by the white rot fungi Ganoderma lucidum and G. tsugae." Canadian Journal of Botany 64, no. 8 (1986): 1611–19. http://dx.doi.org/10.1139/b86-217.

Full text

Abstract:

The in vitro wood decay abilities of Ganoderma lucidum (W. Curt.: Fr.) Karst. and G. tsugae Murr. were studied using the following woods in agar block decay chambers: Vitis vinifera L., Quercus hypoleucoides A. Camus, Prosopis velutina Woot., Abies concolor (Gord. & Glend.) Lindl. ex. Hildebr., and Pseudotsuga menziesii (Mirb.) Franco. Grape wood lost the most weight while mesquite the least. Ganoderma lucidum isolates generally caused greater weight loss of all woods than did G. tsugae isolates. The range of the percent weight losses varied with the wood. Both Ganoderma species caused simultaneous decay in all woods. However, chemical analyses of the decayed blocks indicated that selective delignification by both species also occurred in grape and white fir blocks. Chemical analysis of the decayed oak blocks indicated the percentages of lignin and holocellulose were not statistically different from the controls. However, there was a trend towards delignification. The analyses of the Douglas-fir blocks indicated only simultaneous decay. Scanning electron microscopy demonstrated selective delignification and simultaneous decay of all woods tested. However, the extent of the delignification differed among the wood species. Delignification appeared mainly in areas of tracheids or fiber tracheids, while the rays were simultaneously decayed.

APA, Harvard, Vancouver, ISO, and other styles

Blanchette, R. A. "Delignification by Wood-Decay Fungi." Annual Review of Phytopathology 29, no. 1 (1991): 381–403. http://dx.doi.org/10.1146/annurev.py.29.090191.002121.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Kumar, N. Praveen, and Arun Arya. "Delignification of Valuable Timbers Decayed by India Lignicolous Fungi." International Letters of Natural Sciences 16 (May 2014): 101–20. http://dx.doi.org/10.18052/www.scipress.com/ilns.16.101.

Full text

Abstract:

Wood degrading capacity of lignicolous fungi was studied by decay test. In which two methods were followed, i) wood chips method ii) wood block method. Eight timbers infected by six fungi were selected for studying percentage of decay and biochemical test was done to know delignification. After 12 months, 90 % of wood block of T. arjuna was decayed by L. stereoides. In teak wood 16.82 % of decay was due to H. apiaria in 3 months. As the percentage of moisture was less, percentage of weight loss was also less; this indicated that decay capacity of fungi will depends on % moisture content in wood. The percentage loss in hot water soluble substrates was more in case of T. crenulata due to L. stereoides for 5 months, whereas lowest in case of teak wood decayed by H. apiaria for 5 months. The percentage loss in ethanol benzene soluble substrate was more in case of Adina wood decayed by C. versicolor for 5 months, whereas lowest in case of teak wood infected with L. stereoides for 3 months. As the incubation period increases, percentage loss in acid soluble lignin was more in case of infected woods. L. stereoides, C. versicolor, and H. apiaria showed selective delignification in all infected woods, whereas T. pini showed simultaneous degradation of lignin in all woods tested. The valuable timber like teak wood was not resistant to wood decay because they loss 50% of lignin. The in vitro wood decay test can‟t be taken as absolute evidence for wood decay behavior of lignin-degrading fungi, so we should conform decay of wood by consider biochemical test. For rapid evaluation of wood decay the wood chip method was best suitable. For the first time the wood decay and biochemical test of 8 wood samples infected by white rot fungi like S. commune, L. stereoides, H. apiaria, C. versicolor, T. pini and soft rot fungi like T. viride was studied.

APA, Harvard, Vancouver, ISO, and other styles

Mania, Przemysław, Miłosz Wróblewski, Adam Wójciak, Edward Roszyk, and Waldemar Moliński. "Hardness of Densified Wood in Relation to Changed Chemical Composition." Forests 11, no. 5 (2020): 506. http://dx.doi.org/10.3390/f11050506.

Full text

Abstract:

The aim of this study was to evaluate some of the properties of densified poplar and birch wood earlier subjected to partial delignification of cell walls. The effects of delignification are presented as a comparison of the content of basic structural components in wood before and after chemical modification. In birch wood, the lignin content decreased by 20%, while that of cellulose decreased by 9.7% and that of hemicellulose decreased by 64.9%. In poplar, the lignin content decreased by 34.1%, that of cellulose decreaed by 13.5%, and that of hemicellulose decreased by 58.0%. The hardness of densified birch and poplar wood, after partial reduction of chemical components, was 147 and 111 MPa, respectively, and, compared with natural (non-densified) wood, was almost 4.5 times and 7 times higher, respectively. Poplar wood was more densified (without delignification 238% and after delignification 281%). In the case of birch wood, the density levels were 176% and 188%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

Efanov, M. V., and R. Yu Averin. "Peroxide-Ammonia Delignification of Pine Wood." Chemistry of Natural Compounds 40, no. 2 (2004): 172–75. http://dx.doi.org/10.1023/b:conc.0000033939.81490.d2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Baxi, Pranav B., and Aniruddha B. Pandit. "Using cavitation for delignification of wood." Bioresource Technology 110 (April 2012): 697–700. http://dx.doi.org/10.1016/j.biortech.2012.01.042.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Demirba§, Ayhan. "Aqueous glycerol delignification of wood chips and ground wood." Bioresource Technology 63, no. 2 (1998): 179–85. http://dx.doi.org/10.1016/s0960-8524(97)00063-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Geffert, Anton, Jarmila Geffertova, and Blazej Seman. "The Problems in Delignification of Dry Wood by Kraft Process." Key Engineering Materials 688 (April 2016): 3–9. http://dx.doi.org/10.4028/www.scientific.net/kem.688.3.

Full text

Abstract:

The objective of this study was to assess the causes of the problems arising in the CBC kraft cooking of several types of hardwood chips particularly in view of high dry matter but also in view of chip thickness and character of wood.High dry matter of processed chips influences negatively delignification. Similar effect on delignification is achieved by wood character (anatomic and morphological properties of cell elements, chemical composition, portion of heart and sapwood).Chips thickness has the most significant impact on delignification process comparing to other monitored characteristics. The increase of chips thickness by 1-2 mm has significant negative impact on monitored characteristics of kraft cooking – yield, Kappa number and amount of rejects.Displacement CBC kraft procedure is more sensitive on the deviation from standard conditions than conventional kraft cooking.The problems occurring during kraft cooking of different wood chips mixtures with high dry matter by CBC procedure are possible to resolve by technological and organizational precautions – separate chipping and storage of chips of heart and non-heart woods, preparation of thinner chips of heart wood, chips pre-vaporing before kraft cooking.

APA, Harvard, Vancouver, ISO, and other styles

Yelatontsev, Dmitriy Aleksandrovich, and Elena Vladimirovna Ivanyuk. "DELIGNIFICATION AND PHYSICOCHEMICAL CHARACTERISTICS OF NON-WOOD BIOMASS." chemistry of plant raw material, no. 3 (October 22, 2020): 17–24. http://dx.doi.org/10.14258/jcprm.2020037392.

Full text

Abstract:

The paper presents the of influence peroxide ammonium, alkali, nitric acid, organosolvent and "aqueous ammonia soaking" (AAS) delignification methods on the degree of removal of lignin from non-wood lignocellulosic waste walnut shell Juglans Regia L. and apricot seed Prunus Armeniaca L. It is shown that the maximum degree of delignification (94%) is achieved when processing raw materials with 42 wt% HNO3 and 20 wt% NaOH; the minimum is at peroxide-ammonia treatment (80%). We found that the greatest specific surface area (202 m2∙g-1) provided by the application 42 wt% HNO3, and a maximum iodine number (32 mg∙g-1) when using 25 wt% NH4OH. Delignification significantly increases the specific surface area (5 m2∙g-1 to 120–200 m2∙g-1) iodine number (6.35 mg∙g-1 to 25 to 32 mg∙g-1) of biomass, however, at 45–55% reduced exchange capacity of the material. The obtained cellulose intermediates having acceptable physical and chemical characteristics can be used for further preparation of available sorbents or ion exchange materials. In accordance with the principles of "green chemistry", it is proposed to dispose the spent delignification solutions from AAS and nitric acid methods in liquid nitrogen fertilizers producing.

APA, Harvard, Vancouver, ISO, and other styles

DESHPANDE, RAGHU, LARS SUNDVALL, HANS GRUNDBERG, MARTIN LAWOKO, and GUNNAR HENRIKSSON. "Lignin carbohydrate complex studies during kraft pulping for producing paper grade pulp from birch." September 2020 19, no. 9 (2020): 447–60. http://dx.doi.org/10.32964/tj19.9.447.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

Судакова (Sudakova), Ирина (Irina) Геннадьевна (Gennad'yevna), Наталья (Natal'ya) Викторовна (Viktorovna) Гарынцева (Garyntseva), Анна (Anna) Ильинична (Il’inichna) Чудина (Chudina), and Борис (Boris) Николаевич (Nikolaevich) Кузнецов (Kuznetsov). "REGULARITIES OF THE PROCESS OF PINE WOOD PEROXIDE DELIGNIFICATION IN THE PRESENCE OF SULFURIC ACID CATALYST." chemistry of plant raw material, no. 4 (December 11, 2018): 63–71. http://dx.doi.org/10.14258/jcprm.2018044079.

Full text

Abstract:

The known methods to obtain microcrystalline cellulose (MCC) from wood raw material is multi-stage and it is based on the integration of environmentally hazardous processes of pulping, bleaching and acid hydrolysis of cellulose amorphous part. The paper describes a one-stage catalytic method to obtain microcrystalline cellulose from pine wood based on peroxide delignification in acetic acid-water in the presence of a catalyst H2SO4. The optimal parameters of the process of pine wood peroxide delignification in the presence of 2% H2SO4 catalyst were determined by experimental and numerical methods: temperature – 100 °C, concentration H2O2 – 5 wt.%, CH3COOH – 25 wt.%, LWR 15, duration – 4 h. They provide a high yield of cellulose (45.2 wt.%) with a low content of residual lignin (1.0 wt%).The kinetic study of pine wood peroxide delignification at the temperature range 70-100 ºC was accomplished. The delignification process is described satisfactory by the first order equation in all temperature range. The rate constants vary between 0.08·10-4 and 2.15·10-4 s-1 and the activation energy is 90 kJmol-1. It was established by FTIR and XRD methods, that the cellulose, obtained from pine wood has the composition and structure similar to the commercial microcrystalline cellulose.

APA, Harvard, Vancouver, ISO, and other styles

Mamleeva, Nadezhda A., Stanislav A. Autlov, Natal’ya G. Bazarnova, and Valery V. Lunin. "Delignification of softwood by ozonation." Pure and Applied Chemistry 81, no. 11 (2009): 2081–91. http://dx.doi.org/10.1351/pac-con-08-10-11.

Full text

Abstract:

Ozonation of aspen sawdust of various moisture content (MC) values was investigated. Ozone consumption corresponding to the completion of the ozonation process was shown to be governed by the wood MC. Cellulose-containing material of a low (1–3 %) residual lignin content (LC) was produced under ozonation. It is proposed that ozone dissolved in water is responsible for delignification. The conversion of lignin during softwood ozonation was investigated by UV and Fourier transform-infrared (FT-IR) spectroscopy. The pathways of lignin transformations are influenced by wood MC value.

APA, Harvard, Vancouver, ISO, and other styles

Li, Jianguo, Chaoji Chen, J. Y. Zhu, Arthur J. Ragauskas, and Liangbing Hu. "In Situ Wood Delignification toward Sustainable Applications." Accounts of Materials Research 2, no. 8 (2021): 606–20. http://dx.doi.org/10.1021/accountsmr.1c00075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Paananen, Markus, Stella Rovio, Tiina Liitiä, and Herbert Sixta. "Effect of hydroxide and sulfite ion concentration in alkaline sulfite anthraquinone (ASA) pulping – a comparative study." Holzforschung 69, no. 6 (2015): 661–66. http://dx.doi.org/10.1515/hf-2014-0303.

Full text

Abstract:

Abstract Pulp and black liquor produced by alkaline sulfite anthraquinone (ASA) process were comprehensively characterized to evaluate the effects of ion concentration on the delignification and polysaccharide preservation. Scots pine wood meal was pulped at 160°C with a sulfite-to-hydroxide ion ratio of 0.75 and liquor-to-wood ratio of 200:1. Two concentration levels were studied in presence and absence of anthraquinone (AQ). Contrary to the expectations, already the lower concentration level (L-ASA) revealed rapid delignification in presence of AQ, while only moderate acceleration was obtained at the high concentration level (H-ASA). However, H-ASA liquor resulted in a slightly higher pulp yield of 1–2% (based on wood) but only in case of pulps with kappa numbers (KN) above 60. With progressing delignification, the yield advantage was gradually lost. The higher pulp yield at H-ASA conditions was mainly due to improved galactoglucomannan retention, which was around 2% on KN60 pulp and around 0.5% after prolonged delignification. The xylan content, on the other hand, was found to be 1% (based on wood) lower under H-ASA conditions compared to L-ASA conditions, which may be attributed to an increased solubility of short-chain polysaccharides at high alkali concentration.

APA, Harvard, Vancouver, ISO, and other styles

Wu, Yan, Jichun Zhou, Qiongtao Huang, Feng Yang, Yajing Wang, and Jing Wang. "Study on the Properties of Partially Transparent Wood under Different Delignification Processes." Polymers 12, no. 3 (2020): 661. http://dx.doi.org/10.3390/polym12030661.

Full text

Abstract:

Two common tree species of Betula alnoides (Betula) and New Zealand pine (Pinups radiata D. Don) were selected as the raw materials to prepare for the partially transparent wood (TW) in this study. Although the sample is transparent in a broad sense, it has color and pattern, so it is not absolutely colorless and transparent, and is therefore called partially transparent. For ease of interpretation, the following “partially transparent wood” is referred to as “transparent wood (TW)”. The wood template (FW) was prepared by removing part of the lignin with the acid delignification method, and then the transparent wood was obtained by impregnating the wood template with a refractive-index-matched resin. The goal of this study is to achieve transparency of the wood (the light transmittance of the prepared transparent wood should be improved as much as possible) by exploring the partial delignification process of different tree species on the basis of retaining the aesthetics, texture and mechanical strength of the original wood. Therefore, in the process of removing partial lignin by the acid delignification method, the orthogonal test method was used to explore the better process conditions for the preparation of transparent wood. The tests of color difference, light transmittance, porosity, microstructure, chemical groups, mechanical strength were carried out on the wood templates and transparent wood under different experimental conditions. In addition, through the three major elements (lignin, cellulose, hemicellulose) test and orthogonal range analysis method, the influence of each process factor on the lignin removal of each tree species was obtained. It was finally obtained that the two tree species acquired the highest light transmittance at the experimental level 9 (process parameters: NaClO2 concentration 1 wt%, 90 °C, 1.5 h); and the transparent wood retained most of the color and texture of the original wood under partial delignification up to 4.84–11.07%, while the mechanical strength with 57.76% improved and light transmittance with 14.14% higher than these properties of the original wood at most. In addition, the wood template and resin have a good synergy effect from multifaceted analysis, which showed that this kind of transparent wood has the potential to become the functional decorative material.

APA, Harvard, Vancouver, ISO, and other styles

Мамлеева (Mamleeva), Надежда (Nadezhda) Алексеевна (Alekseevna), Андрей (Andrey) Николаевич (Nikolaevich) Харланов (Kharlanov), Дмитрий (Dmitriy) Германович (Germanovich) Чухчин (Chukhchin), Наталья (Natal'ya) Григорьевна (Grigor'evna) Базарнова (Bazarnova), and Валерий (Valeriy) Васильевич (Vasil'evich) Лунин (Lunin). "DEGRADATION OF PINE WOOD STRUCTURE WHEN OZONOLYTIC DELIGNIFICATION." chemistry of plant raw material, no. 1 (March 6, 2019): 85–94. http://dx.doi.org/10.14258/jcprm.2019015143.

Full text

Abstract:

The pine wood degradation under ozonation was studied. It was determined the contents of lignin (LG) and cellulose (CL) in cellulose-containing material (CM) obtained from the ozonized wood. The degree of polymerization (DP) of cellulose from CM was determined. Samples of CM were investigated using IR diffuse reflectance (DRIFT) spectra and XRD analysis. HPLC analysis of water-soluble LG ozonolysis products was conducted. Ozonation results in 40–42% delignification degree of wood. Aromatics destruction is confirmed by DRIFT spectra. The intensity of stretching band at 1736 cm-1 of unconjugated C=O groups in LG or hemicelluloses markedly increases. A stoichiometric ratio of absorbed ozone and an amount of destructed guaiacylpropane units as well as a composition of water-soluble products show that ozonolysis is a primary mechanism of aromatics degradation in wood. The data on XRD analysis, the amounts of removed LG and the change of cellulose DP allow conclusion that the wood ozonation is accompanied by a destruction of hemicelluloses and amorphous cellulose in the wood. It is shown that the specific ozone uptake £1.5 mmol O3/g matches the domination of the wood delignification with the lowest degradation of cellulose fibers and acceptable efficiency in terms of the ozonation process.

APA, Harvard, Vancouver, ISO, and other styles

Yang, Tiantian, Erni Ma, and Jinzhen Cao. "Dynamic moisture sorption and dimensional stability of furfurylated wood with low lignin content." Holzforschung 74, no. 1 (2019): 68–76. http://dx.doi.org/10.1515/hf-2019-0033.

Full text

Abstract:

AbstractDegradation of lignin occurs naturally in wood due to the influence of microorganisms or photic radiation. To improve the properties of wood with low lignin content, furfuryl alcohol (FA) at the concentration of 25% was used to modify poplar wood (Populus euramericana Cv.) after partial delignification. Moisture sorption and dimensional stability of the samples were investigated under dynamic conditions where the relative humidity (RH) was changed sinusoidally between 45% and 75% at 25°C. Both the moisture content (MC) and the tangential dimensional change varied with a sinusoidal shape similar to the RH. Hygroscopicity and hygroexpansion increased after delignification, while furfurylation led to an inverse impact by reducing MC, dimensional changes, amplitudes of MC and dimensional changes, moisture sorption coefficient (MSC), and humidity expansion coefficient (HEC). After delignification and further furfurylation, the MC and the dimensional changes were reduced by about 20%, and the maximum drop in amplitudes of MC and dimensional changes was about 30%, while the MSC and the HEC decreased by over 15%. In addition, the furfurylated wood with low lignin content exhibited lower sorption hysteresis and swelling hysteresis.

APA, Harvard, Vancouver, ISO, and other styles

SANTOS, RICARDO B., HASAN JAMEEL, HOU-MIN CHANG, and PETER W. HART. "Impact of lignin and carbohydrate chemical structures on kraft pulping processes and biofuel production." TAPPI Journal 12, no. 7 (2013): 23–31. http://dx.doi.org/10.32964/tj12.7.23.

Full text

Abstract:

Most studies aimed at determining rates of hardwood delignification and carbohydrate degradation have focused on understanding the behavior of a single wood species. Such studies tend to determine either the delignification rate or the rate of carbohydrate degradation without examining the potential interactions resulting from related variables. The current study provides a comprehensive evaluation of lignin and carbohydrate degradation during kraft pulping of multiple hardwood species. The kraft delignification rates of Eucalyptus urograndis, E. nitens, E. globulus, sweet gum, maple, red oak, red alder, cottonwood, and acacia were obtained. The kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process for those species also were investigated. The wide ranges of delignification and carbohydrate degradation rates were correlated to wood chemical characteristics. It appears that the syringyl:guaiacyl lignin ratio and lignin-carbohydrate complexes are the main factors responsible for the differences in kraft pulping performance among the hardwoods studied.

APA, Harvard, Vancouver, ISO, and other styles

Kononov, G. N., A. N. Verevkin, Ju V. Serdyukova, and N. A. Nikolenko. "WOOD MYCOLYSIS AS A METHOD OF ITS DELIGNIFICATION." FORESTRY BULLETIN 22, no. 6 (2018): 110–15. http://dx.doi.org/10.18698/2542-1468-2018-6-110-115.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Yang, Tiantian, Jinzhen Cao, and Erni Ma. "How does delignification influence the furfurylation of wood?" Industrial Crops and Products 135 (September 2019): 91–98. http://dx.doi.org/10.1016/j.indcrop.2019.04.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Maurer, A., and D. Fengel. "Delignification and enzyme treatment of ultrathin wood sections." Holz als Roh- und Werkstoff 50, no. 7-8 (1992): 322–26. http://dx.doi.org/10.1007/bf02615363.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Vitas, Selin, Jana Segmehl, Ingo Burgert, and Etienne Cabane. "Porosity and Pore Size Distribution of Native and Delignified Beech Wood Determined by Mercury Intrusion Porosimetry." Materials 12, no. 3 (2019): 416. http://dx.doi.org/10.3390/ma12030416.

Full text

Abstract:

The complex hierarchical structures of biological materials in combination with outstanding property profiles are great sources of inspiration for material scientists. Based on these characteristic features, the structure of wood has been increasingly exploited to fabricate novel hierarchical and functional materials. With delignification treatments, the density and chemistry of wood can be altered, resulting in hierarchical cellulose scaffolds with enhanced porosity for the fabrication of novel hybrid materials. In the present study, focusing on acidic delignification of beech wood and its influence on porosity, we report on a structural characterization and qualitative assessment of the cellulose scaffolds using mercury intrusion porosimetry (MIP). To account for the effect of water removal from the hygroscopic structure, different drying methods—e.g., standard oven and freeze-drying—were applied. While native beech wood is characterized by the presence of macro, meso and micro pores, delignification altered the porosity, increasing the importance of the macropores in the pore size distribution. Furthermore, we showed that the final porosity obtained in the material is strongly dependent on the applied drying process. Samples delignified under harsh conditions at high temperature (mass loss of ~35%) show a 13% higher porosity after freeze-drying compared to oven-dried samples. The obtained results contribute to a better understanding of the impact of the delignification and drying processes on the porosity of cellulose scaffolds, which is of high relevance for subsequent modification and functionalization treatments.

APA, Harvard, Vancouver, ISO, and other styles

Miranda, Isabel, and Helena Pereira. "Kinetics of ASAM and Kraft Pulping of Eucalypt Wood (Eucalyptus globulus)." Holzforschung 56, no. 1 (2002): 85–90. http://dx.doi.org/10.1515/hf.2002.014.

Full text

Abstract:

Summary The kinetics of ASAM and kraft pulping of eucalypt wood (Eucalyptus globulus) were studied in relation to delignification and polysaccharide removal. In comparison to kraft, ASAM pulping had lower mass losses and delignification for the same temperature and reaction times (59.2% at Kappa 25 vs 50.0% at Kappa 17, at 180°C). The ASAM pulps have a higher brightness. ASAM pulping had a short initial period with no mass loss and lignin removal, followed by two reaction phases: a main phase where 61% of lignin was removed (at 180°C) and a subsequent final phase. In comparison to kraft, the main delignification rates of ASAM pulping were approximately 2.5 slower (at 180°C, −1.8 × 10−2 min−1 for ASAM and −4.2 × 10−2 for kraft pulping), and the calculated Arrhenius activation energies were higher (132.4 kJ mol−1 and 83.5 kJ mol−1, respectively). The loss of cellulose was relatively small (12.5 %) and lower than in kraft pulps.

APA, Harvard, Vancouver, ISO, and other styles

Azhari, Azmi, Syamsul Falah, Laita Nurjannah, Suryani Suryani, and Maria Bintang. "Delignifikasi Batang Kayu Sengon oleh Trametes versicolor." Current Biochemistry 1, no. 1 (2014): 1–10. http://dx.doi.org/10.29244/cb.1.1.1-10.

Full text

Abstract:

Delignification is a lignin degradation, a preliminary process in industries that used cellulose containing substrates. Sengon logs are often used for the material in pulp industry because it has high levels of cellulose and low level of lignin. The aim of this study was delignification of sengon logs by using T.versicolor. The methods used include observation growth of T.versicolor compared with Phanerochaete chrysosporium, the rate of of lignin degradation (black liquor), delignification of sengon logs using T.versicolor and the chemical assay of sengon logs before and after delignification. The results of this study showed that delignification by T.versicolor was faster compared to P.chrysosporium based on the rate of lignin degradation (black liquor). The result showed that delignification by T.versicolor at room temperature reduced lignin of sengon logs by 37.31% within 20 days. Chemical assay performed on delignified sengon wood showed decreased level of ethanol benzene, soluble extractive substances, holocellulose, and cellulose and an increase of hemicellulose level.

APA, Harvard, Vancouver, ISO, and other styles

MacKay, John, Tim Presnell, Hasan Jameel, Hidetaka Taneda, David O'Malley, and Ronald Sederoff. "Modified Lignin and Delignification with a CAD-Deficient Loblolly Pine." Holzforschung 53, no. 4 (1999): 403–10. http://dx.doi.org/10.1515/hf.1999.067.

Full text

Abstract:

Summary Lignin composition and lignin removal were investigated in loblolly pines (Pinus taeda L.) deficient in the monolignol biosynthesis enzyme, cinnamyl alcohol dehydrogenase (CAD). The CAD-deficient pines were homozygous for the cad-n1 allele, a mutant form of the gene encoding CAD. We show that lignin from CAD-deficient seedlings is more easily removed by mild alkali at room temperature. The nature of the phenolics recovered from this treatment link the increased lignin solubility to a build up of aromatic aldehyde lignin subunits. We carried out a retrospective genetic analysis to identify a 12 year-old CAD-deficient tree from which we isolated Milled Wood Lignin (MWL) and obtained wood chips for pulping studies. The UV absorption spectra of MWL and the effect of sodium borohydride reduction of MWL showed that the CAD-deficient tree had substantially higher incorporation of aldehyde subunits. The CAD-deficient wood was delignified more extensively than the wild type in soda pulping but not in kraft conditions. More extensive lignin removal, both in mild alkali treatment and in soda pulping, indicate that suppression of CAD in softwood trees may hold promise to produce woods well suited for “milder” pulping conditions that consume less chemicals and generate less waste.

APA, Harvard, Vancouver, ISO, and other styles

Kushnir, Evgeniy Yur'yevich, Anastasiya Gennad'yevna Shakhova, Natal'ya Grigor'yevna Bazarnova, Myrzagul Kymbatbekovna Kymbatbekova, and Irina Vladimirovna Afanasenkova. "DELIGNIFICATION OF PLANT RAW MATERIALS UNDER MICROWAVE IRRADIATION. IR SPECTRA AND ORDERING INDICES OF THE CELLULOSE." chemistry of plant raw material, no. 4 (December 21, 2020): 101–7. http://dx.doi.org/10.14258/jcprm.2020048962.

Full text

Abstract:

The effect of plant raw materials delignification with an 18% solution of peracetic acid under microwave irradiation at a frequency of 2450 MHz on the degree of ordering of the cellulose supramolecular structure was studied. The samples of the obtained cellulose were characterized by FTIR spectroscopy. It was found that microwave heating reduces the rate of ordering of the cellulose supramolecular structure in the process of delignification of wood and straw of annual plants with peracetic acid. In general, the delignification products obtained under microwave irradiation with a treatment time of 30 min are characterized by lower values of the ordering index (0.64–0.79) compared to cellulose samples obtained using heating by thermal conductivity (water bath, 100 °С) at processing time 60 min (0.70–0.86). The IR spectra of cellulose samples obtained with the use of heat conduction heating are characterized by a slightly higher intensity of the band at 1372 cm-1 in comparison with the delignification products obtained under microwave irradiation. It has been shown that the degree of ordering of the cellulose supramolecular structure under the studied delignification conditions is determined by the peculiarities of the composition of the feedstock and the polysaccharides supramolecular organization in the native state. For cellulose obtained from wood and straw, different dependences of the values of the ordering index on the heating method and the residual content of hemicelluloses are characteristic.

APA, Harvard, Vancouver, ISO, and other styles

Ferdous, Taslima, M. A. Quaiyyum, and M. Sarwar Jahan. "Chlorine dioxide bleaching of nineteen non-wood plant pulps." Nordic Pulp & Paper Research Journal 35, no. 4 (2020): 569–76. http://dx.doi.org/10.1515/npprj-2020-0043.

Full text

Abstract:

AbstractBleaching of unbleached and oxygen delignified pulps from nineteen non-wood plants has been evaluated in elemental chlorine free bleaching. Chlorine dioxide charge (kappa factor 0.15, 0.20 and 0.25) and temperature (70 and 85 °C) in the delignification stage (D) were varied. Chlorine dioxide (ClO2) charge and temperature exhibited lower kappa number and higher brightness after alkaline extraction (EP) stage. High temperature ClO2 delignification (DHT) exhibited higher final pulp brightness. The final brightness of wheat straw pulp reached to 90 % after D0/DHT(EP)D1 bleaching, while banana pseudo stem pulp showed the worst bleachability. Residual hexeneuronic acid contents in final pulp from most of the non-wood plants were lower and exhibited 1–2 % higher pulp brightness in DHT process than D0 process. Oxygen delignified pulp and DHT process discharged lower COD load.

APA, Harvard, Vancouver, ISO, and other styles

Adaskaveg, J. E., R. A. Blanchette, and R. L. Gilbertson. "Decay of date palm wood by white-rot and brown-rot fungi." Canadian Journal of Botany 69, no. 3 (1991): 615–29. http://dx.doi.org/10.1139/b91-083.

Full text

Abstract:

Wood from trunks of Canary Island date palm (Phoenix canariensis) was decayed for 12 weeks with white-rot fungi (Ganoderma colossum, G. zonatum, Phanerochaete chrysosporium, Scytinostroma galactinum, or Trametes versicolor) or brown-rot fungi (Wolfiporia cocos, Gloeophyllum trabeum, or Fomitopsis pinicola). Using the vermiculite-block assay, white-rot fungi caused significantly more weight loss (63%) than brown-rot fungi (32%). Of the white-rot fungi, G. colossum caused the greatest weight loss (81%), while S. galactinum caused the least (36%). In contrast, weight loss caused by the brown-rot fungi was similar. Chemical analyses indicated that both white-rot and brown-rot fungi caused losses of starch, holocellulose, and lignin. White-rot fungi, however, removed greater amounts of lignin than the brown-rot fungi with three species, S. galactinum, P. chrysosporium, and G. zonatum, causing selective delignification. Scanning and transmission electron microscopy showed that phloem and parenchyma cells were more susceptible to decay than xylem and fiber cells. Starch grains were degraded by all fungi and were nearly removed in wood decayed by G. colossum. In wood decayed by white-rot fungi, cell walls were eroded and middle lamellae were degraded. Selective delignification was observed in fibers adjacent to vascular tissue in wood decayed by the three white-rot fungi. In wood decayed by brown-rot fungi, walls of ground parenchyma and vascular bundle cells were swollen and fragmented when physically disrupted. In wood decayed by F. pinicola, some cell walls were nearly disintegrated. Key words: selective delignification, simultaneous decay, ultrastructure.

APA, Harvard, Vancouver, ISO, and other styles

Chetvertneva, Irina A., Oleg Kh Karimov, Galina A. Teptereva, Natalia S. Tivas, Eldar M. Movsumzade, and Elbay R. Babayev. "WOOD COMPONENTS AS SOURCES OF PENTO-CONTAINING RAW MATERIALS FOR SYNTHESIS OF USEFUL COMPOUNDS, PRODUCTS AND REAGENTS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 3 (2021): 107–15. http://dx.doi.org/10.6060/ivkkt.20216403.6363.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

Loaiza, Javier M., Ascensión Alfaro, Francisco López, María T. García, and Juan C. García. "Optimization of Laccase/Mediator System (LMS) Stage Applied in Fractionation of Eucalyptus globulus." Polymers 11, no. 4 (2019): 731. http://dx.doi.org/10.3390/polym11040731.

Full text

Abstract:

In a biorefinery framework, a laccase/mediator system treatment following autohydrolysis was carried out for eucalyptus wood prior to soda-anthraquinone pulping. The enzymatic and autohydrolysis conditions, with a view to maximizing the extraction of hemicelluloses while preserving the integrity of glucan, were optimized. Secondly, pulping of solid phase from Eucalyptus globulus wood autohydrolysis and the enzymatic process was carried out and compared with a conventional soda-anthraquinone (AQ) pulping process. The prehydrolysis and enzymatic delignification of the raw material prior to the delignification with soda- Anthraquinone (AQ) results in paper sheets with a lower kappa number and brightness and strength properties close to conventional soda-AQ paper and a liquid fraction rich in hemicellulose compounds that can be used in additional ways. The advantage of this biorefinery scheme is that it requires a lower concentration of chemical reagents, and lower operating times and temperature in the alkaline delignification stage, which represents an economic and environmental improvement over the conventional process.

APA, Harvard, Vancouver, ISO, and other styles

Jang, Jae-Hyuk, Seung-Hwan Lee, and Nam-Hun Kim. "Delignification Effect on Properties of Lignocellulose Nanofibers from Korean White Pine and Their Nanopapers." Journal of the Korean Wood Science and Technology 43, no. 1 (2015): 9–16. http://dx.doi.org/10.5658/wood.2015.43.1.9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Penín, Lucía, Heiko Lange, Valentín Santos, Claudia Crestini, and Juan Carlos Parajó. "Characterization of Eucalyptus nitens Lignins Obtained by Biorefinery Methods Based on Ionic Liquids." Molecules 25, no. 2 (2020): 425. http://dx.doi.org/10.3390/molecules25020425.

Full text

Abstract:

Eucalyptus nitens wood samples were subjected to consecutive stages of hydrothermal processing for hemicellulose solubilization and delignification with an ionic liquid, i.e., either 1-butyl-3-methylimidazolium hydrogen sulfate or triethylammonium hydrogen sulfate. Delignification experiments were carried out a 170 °C for 10–50 min. The solid phases from treatments, i.e., cellulose-enriched solids, were recovered by centrifugation, and lignin was separated from the ionic liquid by water precipitation. The best delignification conditions were identified on the basis of the results determined for delignification percentage, lignin recovery yield, and cellulose recovery in solid phase. The lignins obtained under selected conditions were characterized in deep by 31P-NMR, 13C-NMR, HSQC, and gel permeation chromatography. The major structural features of the lignins were discussed in comparison with the results determined for a model Ionosolv lignin.

APA, Harvard, Vancouver, ISO, and other styles

Romaní, Aloia, Gil Garrote, Francisco López, and Juan Carlos Parajó. "Eucalyptus globulus wood fractionation by autohydrolysis and organosolv delignification." Bioresource Technology 102, no. 10 (2011): 5896–904. http://dx.doi.org/10.1016/j.biortech.2011.02.070.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Blanchette, R. A., and I. D. Reid. "Ultrastructural Aspects of Wood Delignification by Phlebia (Merulius) tremellosus†." Applied and Environmental Microbiology 52, no. 2 (1986): 239–45. http://dx.doi.org/10.1128/aem.52.2.239-245.1986.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Bialski, Alec M., Corinne E. Luthe, Jenny L. Fong, and Norman G. Lewis. "Sulphite-promoted delignification of wood: identification of paucidisperse lignosulphonates." Canadian Journal of Chemistry 64, no. 7 (1986): 1286–94. http://dx.doi.org/10.1139/v86-221.

Full text

Abstract:

Paucidisperse lignosulphonates, previously described as a distinct group of compounds called "hemilignins" [Formula: see text] were conclusively shown to be a complex mixture of monomeric (C9) sulphonic acids. Since these compounds are rapidly solubilized only during the early stages of delignification from softwoods (≤30% lignin removal), it can be concluded that they are selectively removed from the secondary wall and not from the middle lamella. This result gives chemical support to the hypothesis that morphological differences in lignin structure exist. It is proposed that the generation of monolignols and their sulphonated derivatives may occur via an α-O-aryl bond cleavage rather than β-O-aryl cleavage as previously suggested. For softwoods, several other major constituents were isolated, which may be derived from sulphonation of a β-hydroxylated form of coniferyl alcohol.

APA, Harvard, Vancouver, ISO, and other styles

Yoshizawa, Nobuo, Satoru Sagiya, Shinso Yokota, and Toshinaga Idei. "Microspectrometrical Analysis of Ozone Delignification from Wood Cell Walls." Holzforschung 50, no. 1 (1996): 31–36. http://dx.doi.org/10.1515/hfsg.1996.50.1.31.

Full text

APA, Harvard, Vancouver, ISO, and other styles

de Magalhães Erismann, Norma, Ana M. Fernandez, Jaime Baeza, Juanita Freer, Hector Mansilla, and Nelson Duran. "Non-polluting wood and pulp delignification: Biomimetic ligninase system." Biotechnology Letters 12, no. 4 (1990): 305–8. http://dx.doi.org/10.1007/bf01093526.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Mamleeva, N. A., A. N. Kharlanov, D. G. Chukhchin, N. G. Bazarnova, and V. V. Lunin. "Degradation of the Pine Wood Structure in Ozonolytic Delignification." Russian Journal of Bioorganic Chemistry 46, no. 7 (2020): 1330–36. http://dx.doi.org/10.1134/s1068162020070080.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Luna, María Luján, Mónica A. Murace, Gerardo L. Robledo, and Mario C. N. Saparrat. "Characterization of Schinopsis Haenkeana wood Decayed by Phellinus Chaquensis (Basidiomycota, Hymenochaetales)." IAWA Journal 33, no. 1 (2012): 91–104. http://dx.doi.org/10.1163/22941932-90000082.

Full text

Abstract:

Schinopsis haenkeana is a native tree to the Chaco Serrano Forests in Argentina. The white-rot fungus Phellinus chaquensis degrades its wood, causing a whiterot type of decay. The objective of this study was to investigate the structural alterations caused by P. chaquensis in S. hankeana decayed naturally and in vitro. Sound living branches with decay and basidiocarps of P. chaquensis were sampled from the field and in vitro decay tests were performed according to the ASTM D-2017-81 standard method. Naturally decayed branches exhibited an innermost discolored zone with white-rot decay and an outer yellowish-white portion of sound sapwood. Using LM and SEM, degraded tissue displayed diagnostic characters of selective delignification and simultaneous decay. Findings indicate that P. chaquensis causes a mottled pattern of decay (selective delignification plus simultaneous decay) in S. haenkeana wood. Other features such as accumulation of extractives, profuse deposition of crystals and tyloses, typical ofSchinopsis spp. heartwood, were additionally observed. In laboratory degraded material, signs of selective delignification and incipient stages of simultaneous decay were noticeable only microscopically. Chemical analysis revealed an oxidative alteration of aromatic moieties in naturally decayed samples which might be related to the accumulation of phenols as a response to fungal attack when compared to sound samples. Naturally degraded sapwood exhibits anatomical and chemical modifications that indicate the development of discolored wood derived from the host-pathogen interaction.

APA, Harvard, Vancouver, ISO, and other styles

Domínguez, Elena, Pablo G. del Río, Aloia Romaní, Gil Garrote, Patricia Gullón, and Alberto de Vega. "Formosolv Pretreatment to Fractionate Paulownia Wood Following a Biorefinery Approach: Isolation and Characterization of the Lignin Fraction." Agronomy 10, no. 8 (2020): 1205. http://dx.doi.org/10.3390/agronomy10081205.

Full text

Abstract:

Paulownia is a rapid-growth tree with a high biomass production rate per year and low demand of water, which make it very suitable for intercropping systems, as it protects the crops from adverse climatic conditions, benefiting the harvest yields. Moreover, these characteristics make Paulownia a suitable raw material able to be fractionated in an integrated biorefinery scheme to obtain multiple products using a cascade conversion approach. Different delignification pretreatments of biomass have been purposed as a first stage of a lignocellulosic biorefinery. In this study, the formosolv delignification of Paulownia wood was investigated using a second order face-centered factorial design to assess the effects of the independent variables (concentrations of formic and hydrochloric acids and reaction time) on the fractionation of Paulownia wood. The maximum delignification achieved in this study (78.5%) was obtained under following conditions: 60 min, and 95% and 0.05% formic and hydrochloric acid, respectively. In addition, the remained solid phases were analyzed to determine their cellulose content and cooking liquors were also chemically analyzed and characterized. Finally, the recovered lignin by precipitation from formosolv liquor and the pristine lignin (milled wood lignin) in Paulownia wood were characterized and compared by the following techniques FTIR, NMR, high-performance size-exclusion chromatography (HPSEC) and TGA. This complete characterization allowed verifying the capacity of the formosolv process to act on the lignin, causing changes in its structure, which included both phenomena of depolymerization and condensation.

APA, Harvard, Vancouver, ISO, and other styles

Jafari, Vahid, Herbert Sixta, and Adriaan van Heiningen. "Multistage oxygen delignification of high-kappa pine kraft pulp with peroxymonosulfuric acid (Px)." Holzforschung 68, no. 5 (2014): 497–504. http://dx.doi.org/10.1515/hf-2013-0148.

Full text

Abstract:

Abstract In the present study the advantages of multistage oxygen delignification was explored in comparison with a single-stage process at the same level of total caustic charge. A pine kraft pulp with kappa number of 65 (Kn65) was bleached with the focus on the effect of NaOH-charge distribution on Kn, pulp yield, and selectivity of oxygen delignification. The effect of initial chelation with ethylenediaminetetraacetic acid (EDTA) and interstage pulp treatment with peroxymonosulfuric acid (Px) were also investigated. It is shown that the chelated pulp with high Kn may be delignified in three stages to Kn15, but at an unacceptable reduction in pulp viscosity and yield. In contrast, interstage treatment of the chelated pulp with Px at a total charge of 2% active oxygen (based on pulp) in combination with three stages of oxygen delignification enables Kn reduction to about 15 at acceptable viscosity and total yield advantage of about 0.5% (based on wood) compared to an oxygen-delignified kraft pulp with Kn24 derived from the same pine wood chips.

APA, Harvard, Vancouver, ISO, and other styles

Evtuguin, D. V., C. Pascoal Neto, and J. Rocha. "Lignin Degradation in Oxygen Delignification Catalysed by [PMo7V5O40]8- Polyanion. Part I. Study on Wood Lignin." Holzforschung 54, no. 4 (2000): 381–89. http://dx.doi.org/10.1515/hf.2000.065.

Full text

Abstract:

Summary The behaviour of lignin in wood delignification by oxygen in acidic media in the presence of the molybdovanadophosphate heteropolyanion [PMO7V5O40]8−as studied using wet chemistry methods, solid and liquid state 13C NMR spectroscopy. Lignin is oxidised by [PMO7V5O40]8− almost completely to carbon dioxide, with a minor yield of intermediate low-molecular weight aromatic products. The analysis of the reaction products shows that the lignin acidolysis and homolysis involving the oxygen participation in oxidation take place. The residual lignin in the wood residue is more “condensed” and richer in guaiacyl structural units than that in the initial wood. The analysis of “condensed” structures issued from permanganate oxidation of residual lignins suggests that these are formed predominantly by acid-catalysed reactions. The use of an organic solvent, such as ethanol, in the pulping solution favours the oxidative delignification, protecting the lignin against competing reactions (condensation).

APA, Harvard, Vancouver, ISO, and other styles

Yang, Tiantian, Erni Ma, and Jinzhen Cao. "Effects of lignin in wood on moisture sorption and hygroexpansion tested under dynamic conditions." Holzforschung 72, no. 11 (2018): 943–50. http://dx.doi.org/10.1515/hf-2017-0198.

Full text

Abstract:

AbstractEffects of lignin on dynamic sorption and hygroexpansion were investigated. Poplar wood (Populus cathay) [20×20×4 mm3(radial×tangential×longitudinal)] was delignified at three levels and subjected to dynamic humidity changes, where the relative humidity (RH) changed sinusoidally between 45% and 75% at 25°C during 1, 6 and 24 h. Moisture contents (MC) and dimensional responses were recorded automatically. Scanning electron microscopy (SEM) results show that lignin was partly removed. MC and dimensions also varied sinusoidally with RH. At higher delignification levels, amplitudes, moisture sorption coefficients and humidity expansion coefficients became higher, but the phase lag displayed an opposite trend. The effects were due to the removal of the relatively hydrophobic lignin layers, in the course of which more hydroxyl groups of cellulose and hemicelluloses were accessible to humidity. A linear positive relation was found between the delignification rate and MC, and dimensional changes in the tangential direction. Lignin had a significant effect on sorption and hygroexpansion and this effect was greater for static sorption. Delignification reduced the hysteresis due to matrix stiffness decrement of wood, especially in the RH range of 55–65%.

APA, Harvard, Vancouver, ISO, and other styles

Schutyser, W., S. Van den Bosch, T. Renders, et al. "Influence of bio-based solvents on the catalytic reductive fractionation of birch wood." Green Chemistry 17, no. 11 (2015): 5035–45. http://dx.doi.org/10.1039/c5gc01442e.

Full text

Abstract:

In the reductive catalytic fractionation of lignocellulose, the choice of solvent significantly impacts the delignification efficiency, carbohydrate retention in the pulp and the macrostructure of the pulp.

APA, Harvard, Vancouver, ISO, and other styles

Wagih, Ahmed, Merima Hasani, Stephen A. Hall, and Hans Theliander. "Micro/nano-structural evolution in spruce wood during soda pulping." Holzforschung 75, no. 8 (2021): 754–64. http://dx.doi.org/10.1515/hf-2020-0113.

Full text

Abstract:

Abstract Alkaline delignification of wood tissue is the core of the global pulping technology and the most prominent large-scale separation of the main wood components. This work aims at improved understanding of the interplay between the topochemistry of alkaline pulping and the associated morphological changes. Morphology and chemical structure of partially soda-delignified wood chips were studied combining X-ray tomography (XRT), X-ray diffraction analysis and compositional characterization (lignin and carbohydrate content). The XRT studies of wet samples (providing 3D structural information without interfering drying effects), allowed observation of the cell wall separation as an increasing amount of lignin was removed with the increasing pulping time. Comparison between the microstructure of the surface and the central parts of the treated chips showed a more delignified microstructure at the surface, which highlights the dependence of the delignification process on the mass transport (hydroxide ions and lignin fragments) through the wood tissue. The crystallite size of cellulose increased in the <200> crystal planes during the early stage of pulping while there was little effect on the <110> plane.

APA, Harvard, Vancouver, ISO, and other styles

Obataya, Eiichi, Sakae Shibutani, and Kazuya Minato. "Swelling of acetylated wood II: effects of delignification on solvent adsorption of acetylated wood." Journal of Wood Science 53, no. 5 (2007): 408–11. http://dx.doi.org/10.1007/s10086-007-0876-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Claus, Iris, Othar Kordsachia, Nils Schröder, and Ties Karstens. "Monoethanolamine (MEA) pulping of beech and spruce wood for production of dissolving pulp." Holzforschung 58, no. 6 (2004): 573–80. http://dx.doi.org/10.1515/hf.2004.110.

Full text

Abstract:

Abstract Delignification with the use of monoethanolamine (MEA) is an innovative, environmentally friendly chemical pulping process that, in contrast to conventional pulping methods, works without the use of sulphur compounds. Of particular benefit is the simple MEA recovery by distillation, allowing black liquor combustion to be dispensed with and the dissolved lignin to be gained. The MEA process is suitable for pulping both hardwood (e.g. beech) and softwood (e.g. spruce). Compared with conventional processes, the MEA process has the advantage of achieving a high degree of delignification through an increase in temperature during pulping without any appreciable damage to the cellulose. When manufacturing dissolving pulps, however, this specific selectivity of MEA requires the removal of the hemicelluloses in an additional stage, preferably by acid prehydrolysis. The conditions of this prehydrolysis step must be selected specifically to be in keeping with the ultimate use of the dissolving pulp, as this stage involves the cellulose chains being chemically attacked. The residual lignin is removed after pulping in a sequence of different bleaching stages. Substituting MEA for the sodium hydroxide solution required as a bleaching alkali in the oxygen delignification stage proves to be especially beneficial, as in this case the COD after bleaching can be considerably reduced by treating the bleaching filtrate from this stage jointly with the effluents from the MEA pulping process.

APA, Harvard, Vancouver, ISO, and other styles

Bikova, T., V. Klevinska, and A. Treimanis. "Monitoring of Lignin and Hemicelluloses in Spent Cooking Liquor during Kraft Delignification." Holzforschung 54, no. 1 (2000): 66–70. http://dx.doi.org/10.1515/hf.2000.010.

Full text

Abstract:

Summary A direct and rapid method for determining the average molecular weight (MW) and content of lignin and hemicelluloses in spent cooking liquor by high performance size-exclusion chromatography (HPSEC) using a cartridge glass column and 2.5 mM NaOH as an eluent was developed. A Uv290 detector in line with a RI detector was applied to characterise lignin and hemicelluloses, respectively, from liquor during the kraft cooking of grey and black alder wood. During the main delignification stage, the concentration of high-MW wood components in liquor changed through the maximum. The MW values of hemicelluloses in the liquor decreased to DPn = 30 ± 5 and DPw = 55 ± 5. The M̄ n and M̄ w of lignin in spent kraft cooking liquor during the main and final delignification stages did not exceed 3000 and 5000, respectively.

APA, Harvard, Vancouver, ISO, and other styles

Gao, Jie, Jong Sik Kim, and Geoffrey Daniel. "Effect of thermal modification on the micromorphology of decay of hardwoods and softwoods by the white rot fungus Pycnoporus sanguineus." Holzforschung 72, no. 9 (2018): 797–811. http://dx.doi.org/10.1515/hf-2017-0190.

Full text

Abstract:

AbstractThermal modification (TM) of wood at high temperatures can lead to significantly improved decay resistance against white rot (WR) fungi, but little is known about the mechanism of this improvement at the cellular level. As a contribution to this topic, hardwoods (HWs) (ash, beech) and softwoods (SWs) (spruce, fir) were submitted to the Termovuoto®TM process at 220°C for 3–4 h (shortly TMW220°C) and were degraded by the WR fungusPycnoporus sanguineus.The results were studied using microscopy techniques. Decay occurred preferentially via cell wall delignification prior to the removal of cellulose and hemicelluloses. Concerning this effect and fungal colonization, there were no essential differences between TMW220°Cand the unmodified reference of all wood species. TMW220°C, however, showed a number of characteristic changes in decay morphology. Narrow and distinct concentric transition zones were observable in decayed fiber and tracheid cell walls, which demark the lignified and delignified regions. Moreover, cell wall separation by preferential delignification of compound middle lamellae (CML) was not seen in decayed tracheids. It can be concluded that the Termovuoto TMW220°Cprocess has an impact on the delignification process ofP. sanguineusat the cell wall level, which slows down the decay.

APA, Harvard, Vancouver, ISO, and other styles

Хакимова (Khakimova), Фирдавес (Firdaves) Харисовна (Kharisovna), Роман (Roman) Рашидович (Rashidovich) Хакимов (Khakimov), and Ольга (Ol'ga) Алексеевна (Аlekseevna) Носкова (Noskova). "YOUNG WOOD OF SPRUCE AND BIRCH – COMPLETE RAW MATERIAL FOR PULP AND PAPER INDUSTRY." chemistry of plant raw material, no. 3 (March 27, 2018): 261–70. http://dx.doi.org/10.14258/jcprm.2018033782.

Full text

Abstract:

The work is devoted to increase in complexity of use of wood raw materials – one of the most important directions in solution to complying with the modern requirements of rational environmental management and environmental protection.Features of impregnation by bisulfite sulfite cooking acid and regularities of bisulfite delignification of young and ripe fir-tree and birch wood have been investigated. It is shown that young thin wood of both breeds becomes impregnated by bisulfite sulfite cooking acid much quicker, than ripe. The nature of delignification processes for young and ripe wood are identical, however intensity of processes is much lower for young wood.It has been established that cellulose derived from young wood is ground easier and has higher mechanical strength rates than from ripe. However cellulose from young wood is dehydrated slightly more difficultly and has the increased water-retaining what is connected with differences in sizes and properties of fibers of young and ripe wood.Cellulose yields of young and ripe wood differ insignificantly. Cellulose from young birch wood characterized by a somehow lowered owing due to the higher content of knots of this wood.Young wood is dignified by bisulfite cooking liquor without difficulties, but slightly more slowly in comparison with the corresponding ripe wood breed. The research results showed that the young (thin) fir-tree and birch wood of which is formed at cleaning cutting is the considerable reserve stock of wood raw materials which can be successfully utilized fibrous semi-finished products production, in particular in bisulfite cellulose.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!