Characterization of Anthocephalus Cadamba and its Delignification by Kraft Pulping

TAPPI Journal ◽  
2010 ◽  
Vol 9 (3) ◽  
pp. 30-37 ◽  
Author(s):  
MOHAN LAL ◽  
DHARM DUTT ◽  
C. H. TYAGI ◽  
J. S. UPADHYAY ◽  
SIDDHARTHA UPADHYAY

Anthocephalus cadamba is a fast-growing deciduous tropical hardwood with anatomical, morphological, and chemical characteristics that make it suitable for pulp production. The fibers are short but fiber width, cell wall thickness, and rigidity coefficient of A. cadamba are comparable to those of softwoods such as Pinus kesiya and Picea abies. Due to low lignin and high holocellulose contents, A. cadamba produces high pulp yield at milder cooking conditions. We studied the effect of sulfidity, cooking time, and temperature on pulp yield and kappa number during kraft pulping. The effect of ageing on pulp yield, kappa number, and viscosity indicated that 4-year-old A. cadamba is suitable for pulp production and produces optimal strength properties at 44 Schopper-Riegler degree (°SR).

2018 ◽  
Vol 33 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Gustavo B. de Souza ◽  
Jorge Luiz Colodette ◽  
Fernando José Borges Gomes ◽  
Danila Morais de Carvalho

AbstractThe improvement caused by eucalypt chip impregnation on kraft pulping performance was assessed for terminating the cook at kappa in the range of 15–27 and at controlled residual effective alkali (REA) of 6–8 g/L NaOH. Extended impregnation cooking of eucalypt chips (EIC) increased about 1 %lignin- and HexA-freescreen yield gains in relation to conventional cooking (CC), regardless of kappa number in the range of 15–27. The EIC technology allows for cooking eucalypt wood to kappa number up to 27, without rejects production, but without significant improvement inlignin- and HexA-freescreen yield and with larger chlorine dioxide (ClO2) consume during bleaching. The optimum kappa number for both CC and EIC cooking was about 19 with similar refinability and strength properties for both technologies, CC and EIC. It was concluded that extended impregnation cooking is an attractive technique for enhancing bleached eucalypt Kraft pulp yield.


2020 ◽  
Vol 35 (3) ◽  
pp. 325-331
Author(s):  
Sandeep Kumar Tripathi ◽  
Izhar Alam ◽  
Nishi Kant Bhardwaj

AbstractEffect of different proportions of bark in mixed hardwood (about 70 % eucalyptus and 30 % poplar) chips on pulp and papermaking properties was studied. Increased proportion of bark in raw material chips resulted in increased active alkali consumption, increased reject content in pulp and reduced pulp yield after kraft pulping. The unbleached pulp obtained with higher proportion of bark in mixed hardwood chips also has higher kappa number, lower brightness and viscosity as compared to pulp obtained with bark free mixed hardwood chips. The soda loss and ash content in pulp were severely increased from 12.8 kg/t to 312 kg/t of pulp and 0.7 % to 21.1 %, respectively with the increase of bark portion from 0 to 100 % in raw material furnish. The physical strength properties like tensile, burst and tear indices in the pulp obtained from bark were reduced by 58.5 %, 60.7 % and 68.4 %, respectively as compared to that with bark free mixed hardwood.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5361-5375
Author(s):  
Laxman Kumar Pandey ◽  
Amit Kumar ◽  
Surendra Pal Singh ◽  
Dharm Dutt

Mechanical pulping of raw wood material is a highly energy intensive and pollution generating step in the papermaking process. This study focused on combined mechanical and xylanase treatment prior to the kraft pulping of E. tereticornis. A screened pulp yield of 49.1% (on oven-dry wood basis) with a Kappa number of 24.9 was obtained at the optimum cooking temperature of 160 °C without any pretreatment of the wood chips. After mechanical treatment (destructuring), a slightly higher screened pulp yield (49.4%) was obtained with a Kappa number of 24.2 at the cooking temperature of 145 °C with the same active alkali charge (15%). The optimum cooking temperature was further reduced to 140 °C for the destructured xylanase-treated wood chips. The xylanase treatment resulted in a 2% reduction in screened pulp yield due to hydrolysis of xylan. However, the Kappa number was reduced to 18.2 after xylanase pretreatment of the mechanically destructured wood chips. The combined pretreatment (destructured and xylanase treatment) of wood chips resulted in a reduction in cooking temperature by 20°C compared to untreated wood chips. Such a reduction in cooking temperature can effectively reduce steam consumption. The combined pretreatment improved the pulp brightness by 2.0 (ISO points) and physical strength properties, which included the tensile index, tear index, and burst index by 11.06%, 21.72%, and 21.79%, respectively, compared to the control.


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.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (5) ◽  
pp. 287-293 ◽  
Author(s):  
JANNATUN NAYEEM ◽  
M. SARWAR JAHAN ◽  
RAZIA SULTANA POPY ◽  
M. NASHIR UDDIN ◽  
M.A. QUAIYYUM

Jute cutting, jute caddis, and cutting-caddis mixtures were prehydrolyzed by varying time and temperature to get about 90% prehydrolyzed yield. At the conditions of 170°C for 60 min of prehydrolysis, the yield for 100% jute cutting was 76.3%, while the same for jute caddis was only 67.9%. But with prehydrolysis at 150°C for 60 min, the yield was 90% for jute cutting, where 49.94% of original pentosan was dissolved and prehydrolysis of jute caddis at 140°C in 60 min yielded 86.4% solid residue. Jute cutting-caddis mixed prehydrolysis was done at 140°C for 30 min and yielded 92% solid residue for 50:50 cutting-caddis mixtures, where pentosan dissolution was only 29%. Prehydrolyzed jute cutting, jute caddis, and cutting-caddis mixtures were subsequently kraft cooked. Pulp yield was only 40.9% for 100% jute cutting prehydrolyzed at 170°C for 60 min, which was 10.9% lower than the prehydrolysis at 140°C. For jute cutting-caddis mixed prehydrolysis at 140°C for 45 min followed by kraft cooking, pulp yield decreased by 3.3% from the 100% cutting to 50% caddis in the mixture, but 75% caddis in the mixture decreased pulp yield by 6.7%. The kappa number 50:50 cutting-caddis mixture was only 11.3. Pulp bleachability improved with increasing jute cutting proportion in the cutting-caddis mixture pulp.


TAPPI Journal ◽  
2020 ◽  
Vol 19 (10) ◽  
pp. 511-524
Author(s):  
TASLIMA FERDOUS ◽  
M.A. QUAIYYUM ◽  
KAZI M. YASIN ARAFAT ◽  
M. SARWAR JAHAN

In this paper, chia plant was characterized in terms of chemical, morphological, and anatomical properties. Chia plant was characterized with low α-cellulose (30.5%); moderate lignin (23.2%) with syringyl to guaiacyl ratio of 1.41; and shorter fiber length (0.67 mm) with thinner cell wall (1.91 μm) and good flexibility coefficient (71.44). Anatomical features showed that chia plant consists of vessels, fibers, parenchyma cells, and collenchyma cells. Chia plant pulping was evaluated in soda-anthraquinone (soda-AQ) and formic acid/peroxyformic acid (FA/PFA) processes. Chia plant was difficult to delignify in the alkaline process. The FA/PFA process produced higher pulp yield at the same kappa number than the soda-AQ process. Unbleached soda-AQ chia pulp exhibited good proper-ties in terms of tensile, bursting, and tearing strengths, even at the unrefined stage, due to high drainability of the pulps. Alkaline peroxide bleached FA/PFA pulp exhibited better papermaking properties and 2% higher brightness than the D0(EP)D1 bleached soda-AQ pulp.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9243-9264
Author(s):  
Luis Fernando Pintor-Ibarra ◽  
José de Jesús Rivera-Prado ◽  
Sarai Ramos-Vargas ◽  
Teófilo Escoto-García ◽  
Nancy Eloisa Rodríguez-Olalde ◽  
...  

Eichhornia crassipes (water hyacinth) was pulped by means of a kraft pulping process with reagent loads of 10 and 20% on a dry matter basis to determine yield, rejects, kappa number, and ash. Fiber classification, brightness, opacity, and viscosity were measured in the brown pulp. Bleaching was performed by means of an O1O2D1(PO)D2HD3 sequence. Yield, kappa number, pH, ash, brightness, opacity, and viscosity were evaluated in the bleached pulp. Finally, a microanalysis of inorganic elements was carried out in both the bleached and unbleached pulp ash. The highest kraft pulp yield was 26.4%, with a 10% reagent load at 120 °C and 30 minutes cooking. It was determined that E. crassipes cellulosic pulp contains large amounts of fines. Results of the bleaching sequence indicate low brightness (58.0 %) and low viscosity (6.43 cP). The most abundant inorganic elements in the ash of both bleached and unbleached pulp were Ca, Mg, P, and Si. These results suggest that E. crassipes biomass might complement cellulosic fibers in pulping processes of low yield, such as the wood fibers used to produce handmade paper.


2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan

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


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.


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