scholarly journals Pulp and Papermaking Characteristics of South Sudanese Cordia Africana (Gambil) Wood

2021 ◽  
Author(s):  
Osman Taha Elzaki ◽  
Selim Otuk Tuphach ◽  
Tarig Khider

Abstract Objective The wood of an important indigenous Sudanese hardwood species, Cordia africana lam, was examined to determine its suitability for pulp and papermaking. Basic density, bark-to-wood ratio, fiber dimensions and chemical composition were studied. Results Pulps were evaluated and papermaking characteristics were tested. C. africana wood showed medium basic density (410 kg m-1). The average bark-to wood ratio by mass (6.82%) and volume (11.67%) were in the normal average for pulpwood and could be used for production of high grade pulp. The fibers of C. africana were long with an average fiber length of 1.13 mm, average fiber diameter was 30 µm with an average lumen diameter 20 µm and cell wall thickness of 5 µm. the wood showed high ash content (2.7%), high pentosans (25%), relatively medium lignin content (23.9%).C. africana pulped with 12-15% alkali charge as Na2O for two hours at 170 0C gave good Kappa numbers with normal and relatively high yield with very low rejects. The addition of 0.13% anthraquinone (AQ) in cooking liquor reduced the active alkali consumption by 2-2.3%, increased the pulp yield and reduced bleachable Kappa numbers. The pulp produced suitable for wrapping paper and paperboard.

2020 ◽  
Author(s):  
Osman Taha Elzaki ◽  
Selim Otuk Tuphach ◽  
Tarig Khider

Abstract The wood of an important indigenous Sudanese hardwood species, Cordia africana lam, was examined to determine its suitability for pulp and papermaking. Basic density, bark-to-wood ratio, fiber dimensions and chemical composition were studied. Pulps were evaluated and papermaking characteristics were tested. C. africana wood showed medium basic density (410 kg m-1). The average bark-to wood ratio by mass (6.82%) and volume (11.67%) were in the normal average for pulpwood and could be used for production of high grade pulp.The fibers of C. africana were long with an average fiber length of 1.13 mm, average fiber diameter was 30 µm with an average lumen diameter 20 µm and cell wall thickness of 5 µm. the wood showed high ash content (2.7%), high pentosans (25%), relatively medium lignin content (23.9%).C. africana pulped with 12-15% alkali charge as Na2O for two hours at 170 0C gave good Kappa numbers with normal and relatively high yield with very low rejects. The addition of 0.13% anthraquinone (AQ) in cooking liquor reduced the active alkali consumption by 2-2.3%, increased the pulp yield and reduced bleachable Kappa numbers. The pulp produced suitable for wrapping paper and paperboard.


2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira

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


2006 ◽  
Vol 41 (12) ◽  
pp. 1687-1691 ◽  
Author(s):  
Ana Maria Loureiro da Seca ◽  
Fernando Manoel de Jesus Domingues

The objective of this work was to evaluate the use of basic density and pulp yield correlations with some chemical parameters, in order to differentiate an homogeneous eucalyptus tree population, in terms of its potential for pulp production or some other technological applications. Basic density and kraft pulp yield were determined for 120 Eucalyptus globulus trees, and the values were plotted as frequency distributions. Homogenized samples from the first and fourth density quartiles and first and fourth yield quartiles were submitted to total phenols, total sugars and methoxyl group analysis. Syringyl/guaiacyl (S/G) and syringaldehyde/vanillin (S/V) ratios were determined on the kraft lignins from wood of the same quartiles. The results show the similarity between samples from high density and low yield quartiles, both with lower S/G (3.88-4.12) and S/V (3.99-4.09) ratios and higher total phenols (13.3-14.3 g gallic acid kg-1 ). Woods from the high yield quartile are statistically distinguished from all the others because of their higher S/G (5.15) and S/V (4.98) ratios and lower total phenols (8.7 g gallic acid kg-1 ). Methoxyl group and total sugars parameters are more adequate to distinguish wood samples with lower density.


TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM

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.


2010 ◽  
Vol 40 (5) ◽  
pp. 917-927 ◽  
Author(s):  
Desmond J. Stackpole ◽  
René E. Vaillancourt ◽  
Geoffrey M. Downes ◽  
Christopher E. Harwood ◽  
Brad M. Potts

Pulp yield is an important breeding objective for Eucalyptus globulus Labill., but evaluation of its genetic control and genetic correlations with other traits has been limited by its high assessment cost. We used near infrared spectroscopy to study genetic variation in pulp yield and other traits in a 16-year-old E. globulus trial. Pulp yield was predicted for 2165 trees from 467 open-pollinated families from 17 geographic subraces. Significant differences between subraces and between families within subraces were detected for all traits. The high pulp yield of southern Tasmanian subraces suggested that their economic worth was previously underestimated. The narrow-sense heritability of pulp yield was medium (0.40). The significant positive genetic correlation between pulp yield and diameter (0.52) was at odds with the generally neutral values reported. The average of the reported genetic correlations between pulp yield and basic density (0.50) was also at odds with our nonsignificant estimate. Pulp yield of the subraces increased with increasing latitude, producing a negative correlation with density (–0.58). The absence of genetic correlations within subraces between pulp yield and density suggests that the correlation may be an independent response of the two traits to the same or different selection gradients that vary with latitude.


2018 ◽  
Vol 53 (2) ◽  
pp. 83-88 ◽  
Author(s):  
KMY Arafat ◽  
J Nayeem ◽  
AH Quadery ◽  
MA Quaiyyum ◽  
M Sarwar Jahan

Banana fibre is a natural fibre with high strength, which can be blended easily with cotton fibre or synthetic fibre to produce composite material. In the fiber extraction process, a substantial amount of lignocellulosic wastes are generated, disposal of which creates problem in the adjacent area. In this paper, extracted banana fiber (EBF) and waste banana fiber (WBF) were characterized in terms of chemical and morphological properties to produce handmade paper. WBF was characterized with lower α–cellulose, lignin content and longer fiber length. Pulping of EBF and WBF was carried out with varying active alkali and cooking time at boiling temperature. Pulp yield of WBF was 35.9% after 120 min of cooking with 8% alkali charge. In the unbeaten state the degrees of drainage resistance i.e. SR values were 65 and 71 for EBF and WBF, respectively. The tensile, burst and tear indices of WBF were 23.7 N.m/g, 2.2 kPa.m2/g and 5.0 mN.m2/g, respectively; these were much lower as compared to EBF. These values however, meet the requirement for handmade paper.Bangladesh J. Sci. Ind. Res.53(2), 83-88, 2018


Author(s):  
Olga V. Yatsenkova ◽  
Andrei M. Skripnikov ◽  
Boris N. Kuznetsov

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content <1% wt. at a low concentration of hydrogen peroxide (3% wt.) in the reaction medium was established. The optimal concentrations of reagents (Н2О2 – 3% wt., CH3COOH – 38.9% wt.) and the duration of the process (4 h) were determined by experimental and calculation methods. This conditions provide a high yield of cellulose product (≥45% wt.) with a low content of residual lignin (<1% wt.). The composition and structure of fir cellulose was studied by chemical analysis and by FTIR and SEM methods. The cellulosic product which was obtained in optimal process conditions is high-quality cellulose


BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6826-6839
Author(s):  
Junjun Kong ◽  
Ling Zhang ◽  
Ziyi Niu ◽  
Rina Wu ◽  
Gaosheng Wang

In view of environmental and economic issues, co-production technology with pulp as the major product is an important developmental direction in biorefinery. In this paper, high-yield pulp was prepared by hydrothermal pretreatment with controlled pH and subsequent mechanical refining using corn stover as raw material. By adding acetic acid or sodium hydroxide, the properties of the hydrolysate and the pulp were altered. Reducing the pH during hydrothermal pretreatment resulted in more cellulose and hemicellulose being released, while less lignin was released. Increased pH led to more lignin being released, while dissolution of carbohydrates did not change significantly. A maximum pulp yield at pH 5.84 of hydrolysate was obtained when 3.0% sodium hydroxide was used. The strength of pulp is highly related to the removal of lignin during hydrothermal pretreatment. The relationship between pH value in hydrothermal pretreatment and the physical properties of the pulp was established and could be further used for prediction and as guidance for process control. Moreover, the results could be used to develop technologies for industrial utilization of agricultural straw to co-generate fiber and other bio-based products.


Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова ◽  
Д.Д. Манойлович

Получение доступных сорбентов на основе природных материалов, для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах является актуальным направлением исследований. Сорбенты на основе технической целлюлозы удовлетворяют этим требованиям. В работе для получения технической целлюлозы предложено использовать биомассу соломы риса. Для удаления из соломы риса минерального компонента при проведении окислительно-органосольвентной варки используют стадию щелочной обработки, которая приводит к деструкции полисахаридов, снижая выход технической целлюлозы. В связи с этим целью работы является изучение закономерностей проведения щелочной обработки соломы риса для максимального сохранения высокого выхода технической целлюлозы, извлечения минеральной части и возможности применения данной целлюлозы в качестве колористического сорбента. С учетом предварительных исследований найдены оптимальные значения технологических факторов, обеспечивающих высокий выход волокнистого материала из соломы риса при минимальном содержании в нем минеральных компонентов. Последующая органосольвентная варка позволяет получить техническую целлюлозу с выходом – 48,8% от абсолютно сухого сырья (а.с.с), зольностью 0,05% от а.с.с., содержанием лигнина 2,5% от а.с.с., удовлетворительными прочностными характеристиками, высокими сорбционными свойствами, необходимой белизной и рН водной вытяжки. Выявлено, что техническая целлюлоза из соломы риса содержит металлы, накопленные биомассой за вегетативный период. Щелочная обработка и окислительно-органосольвентная делигнификация в большинстве случаев приводят к снижению концентрации металлов в технической целлюлозе. Исключение составляют алюминий, железо и свинец, содержание которых в технической целлюлозе увеличивается. Таким образом, целлюлоза, полученная в оптимальных условиях щелочной обработки и последующей окислительно-органосольвентной варки из соломы риса, с учетом содержащихся в ней металлов, пригодна для использования в качестве сорбента для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах. Receive available sorbents based on natural materials for visual color determination of the content of metal ions in contaminated natural and waste waters is a topical area of research. Sorbents on the basis of technical cellulose satisfy these requirements. In the process of obtaining technical cellulose is proposed to use biomass straw rice. Removal of straw rice mineral component when carrying out the oxidation-organosolvent use the cooking stage alkali treatment, which leads to degradation of polysaccharides, reducing the output of technical cellulose. In this regard, the aim of this work is to study the regularities of the alkaline treatment of rice straw for maximum preservation of the high output technical cellulose, extracting the mineral and the possibility of using the cellulose as the colour of the sorbent. Taking into account the preliminary studies, optimal conditions of technological factors were found ensuring a high yield of fibrous material from rice straw with a minimum content of mineral components in it. Subsequent organosolvent pulping yields technical pulp with a yield of 48.8% bone dry raw material (BDRM), an mineral ash content of 0.05% of BDRM, a lignin content of 2.5% of BDRM, satisfactory strength properties, high sorption properties, the necessary whiteness and pH of aqueous extract. It is revealed that the technical cellulose from straw of rice contains metals accumulated biomass during the vegetation period. Alkaline treatment and oxidative-organosolvent the delignification in most cases leads to a decrease of metal concentrations in pulp technical. With the exception of aluminum, iron and lead, the content of which is technical cellulose increases. Thus, cellulose obtained in optimum conditions of alkaline treatment and subsequent oxidation-organosolvent pulping of straw of rice, taking into account the contained metals suitable for use as a sorbent for visual color determination of the content of metal ions in polluted natural and sewage waters.


2000 ◽  
Vol 30 (1) ◽  
pp. 136-144 ◽  
Author(s):  
C A Raymond ◽  
A Muneri

The effects of N and P fertilizers applied to Eucalyptus globulus Labill. at plantation establishment on basic density, fibre length, fibre coarseness, predicted pulp yield, and N and P concentration in the wood were examined by sampling four fertilizer factorial trials: three in Victoria and one in Western Australia. Treatments sampled were control, maximum levels of N and P by themselves and combined. Growth responses varied across sites with significant growth responses at the Victorian sites but no response at the Western Australian site. An interaction was suggested between rainfall and the effects of the fertilizer; wood properties at the drier sites were detrimentally affected by fertilizer but there was little effect at the wetter sites. On the two drier sites, application of both N and P, alone or in combination, resulted in changes in density, shorter fibres, and slightly lower predicted pulp yield. Addition of both N and P increased the levels of these nutrients in the wood at the three Victorian sites. Changes occurred in wood properties in the absence of growth responses to the applied fertilizer indicating that these changes were not induced by changing tree growth rate.


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