Improving Bleached Pulp Yield and Paper Strength Properties of Eucalyptus Through Integrating Kraft Pulping to High Kappa Number and Oxygen Delignification

2012 ◽  
Vol 6 (5) ◽  
pp. 531-537 ◽  
Author(s):  
Xiaolin Luo ◽  
Huichao Hu ◽  
Xin Sheng Chai ◽  
Shilin Cao ◽  
Liulian Huang ◽  
...  
Keyword(s):  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Paper Strength ◽  
Oxygen Delignification ◽  
Bleached Pulp

Enhancement of eucalypt pulp yield through extended impregnation cooking

2018 ◽  
Vol 33 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Gustavo B. de Souza ◽  
Jorge Luiz Colodette ◽  
Fernando José Borges Gomes ◽  
Danila Morais de Carvalho
Keyword(s):  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield

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.

scholarly journals CHARACTERISATION OF MORINGA OLEIFERA (DRUMSTICK) WOOD FOR PULP AND PAPER MAKING

2021 ◽  
Vol 55 (3-4) ◽  
pp. 255-262
Author(s):  
ARVIND SHARMA ◽  
GUNJAN DHIMAN ◽  
PRITI S. LAL ◽  
RAVI D. GODIYAL ◽  
BIPIN P. THAPLIYAL
Keyword(s):  
Mechanical Strength ◽  
Moringa Oleifera ◽  
Acacia Mangium ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp And Paper ◽  
Paper Making ◽  
Bleached Pulp ◽  
Optimized Conditions

"Moringa oleifera (drumstick) wood was evaluated in terms of its chemical composition, morphological features, Kraft pulping behavior, ECF bleaching and mechanical strength properties – important parameters for pulp and paper making – in comparison with Acacia mangium. Moringa oleifera was found to have the following composition: holocellulose 65.5%, lignin 20.5%, pentosan 11.6%, -cellulose 40.5% and extractives content of 5.15%, which made it comparable with the Acacia mangium wood sample. The alkali prehydrolysis of Moringa oleifera was carried out using 2% NaOH at 150 °C. The prehydrolysis liquor (PHL) was found to contain 50.9 mg/kg of calcium, 5140 mg/kg of potassium and 312 mg/kg of iron content. The prehydrolysis step was followed by Kraft pulping in order to obtain chemical grade pulp of kappa number 15-16 under optimized conditions. The Moringa oleifera pulp was bleached using the DEpD bleaching sequence to reach 85% brightness (ISO). The bleached pulp had an average fiber length of 1.21 mm, which was higher than that of Acacia mangium – 0.782 mm. The mechanical strength properties of the unbleached and bleached pulps, such as tear, tensile and burst indices, were also determined to show their suitability for pulp and paper production."

TCF High-Brightness Bleaching NaOH-AQ Pulp of Fast-Growing Poplar with Low Kappa Number

2012 ◽  
Vol 217-219 ◽  
pp. 837-842
Author(s):  
Xing Xiang Ji ◽  
Jia Chuan Chen ◽  
Gui Hua Yang ◽  
Zhong Jian Tian
Keyword(s):  
Oxygen Pressure ◽  
Ph Value ◽  
Kappa Number ◽  
Pulp Yield ◽  
Oxygen Delignification ◽  
High Brightness ◽  
Fast Growing ◽  
Bleached Pulp ◽  
Initial Ph ◽  
Pulp Consistency

In the paper, technological conditions suitable for H2O2 strengthened oxygen delignification of fast growing poplar NaOH-AQ pulp with low kappa number (Kappa number 13.5, viscosity 851ml/g, brightness37%ISO) were investigated, based on which (Q/OP) QP Totally Chlorine Free (TCF) bleaching sequence was studied, and the TCF high-brightness bleaching of NaOH-AQ pulp with low kappa number was realized. Conditions better suitable for (Q/OP)QP bleaching of NaOH-AQ pulp with low kappa number are as follows: at the stage of H2O2 strengthened oxygen delignification: pulp consistency 10%, alkali dosage 2.5%, H2O2 dosage 3%, MgSO4 dosage 0.5%, oxygen pressure 0.6Mp, temperature 100°C, time 60min; at Q stage: pulp consistency 8%, DTPA 0.3%, initial pH value 4, temperature 70°C, time 120min; at P stage: pulp consistency 10%,H2O2 dosage 2%, MgSO4 dosage 0.5%, Na2SiO3 dosage 0.7％, temperature 70°C, pH value 12, time 120min. With this sequence, the pulp can be bleached with brightness of 82.0%ISO, viscosity 716ml/g, and the bleached pulp yield ratio 91.78％.

Research on Kraft Pulping Delignification of Bamboo (Neosinocalamus)

2011 ◽  
Vol 418-420 ◽  
pp. 2241-2244
Author(s):  
Pei Yi Li ◽  
Mei Yun Zhang ◽  
Xin Xing Xia ◽  
Chun Tao Lin
Keyword(s):  
Fiber Material ◽  
Wide Distribution ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
Oxygen Delignification ◽  
Local Conditions ◽  
Bamboo Pulp

Bamboo, as a kind of non-wood raw material, has a long, thin fiber with wide distribution and rich abundance in China. Its pulping properties are between softwood and hardwood. Adapting to the Chinese situation, developing bamboo pulp industrialization, according to the local conditions, is an available way to solve the shortage of fiber material for paper-making. Delignification of bamboo (Neosinocalamus) was carried out by conventional kraft and soda pulping under varying conditions to determine the relationships between selected cooking parameters (EA 14~20%, sulfidity 0~40%, maximum temperature 160 and 165°C, and time at maximum temperature 60~110 min) and pulp properties (kappa number and yield). Results indicated that in order to obtain relatively low kappa numbers(17~27), high sulfidity(20~40%) at lower EA(14~16%) increased pulp yield compared to the case of low sulfidity(0~10%) at higher EA(16~18%). Pulp with lower kappa numbers (13~15) and acceptable yield can be obtained at a sulfidity level of 20~30% with 18% EA or at a sulfidity level of 10~30% with 20% EA. Meanwhile, bamboo pulp in this condition not only helps to decrease kappa number in the subsequent oxygen delignification process, but also reduces the cost of chemicals in the bleaching process.

Effect of bark content in mixed hardwood chips on pulp and papermaking properties

2020 ◽  
Vol 35 (3) ◽  
pp. 325-331
Author(s):  
Sandeep Kumar Tripathi ◽  
Izhar Alam ◽  
Nishi Kant Bhardwaj
Keyword(s):  
Strength Properties ◽  
Ash Content ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Pulp Yield ◽  
Physical Strength ◽  
Alkali Consumption ◽  
Unbleached Pulp

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.

scholarly journals Xylanase pretreatment of mechanically destructured chips of Eucalyptus tereticornis and its effect on kraft pulping

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5361-5375
Author(s):  
Laxman Kumar Pandey ◽  
Amit Kumar ◽  
Surendra Pal Singh ◽  
Dharm Dutt
Keyword(s):  
Treated Wood ◽  
Untreated Wood ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Wood Chips ◽  
Pulp Yield ◽  
Physical Strength ◽  
Cooking Temperature ◽  
Combined Pretreatment

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.

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
Keyword(s):  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Tropical Hardwood ◽  
Pinus Kesiya ◽  
Rigidity Coefficient ◽  
Pulp Production ◽  
Anthocephalus Cadamba

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).

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

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

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

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

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

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

Prehydrolysis kraft pulping of jute cutting and caddis mixture for rayon production

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
Keyword(s):  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Solid Residue ◽  
Rayon Production ◽  
Kraft Cooking ◽  
Prehydrolysis Kraft

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.

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