Accelerating kraft pulping with hydroxyethylidene diphosphonic acid (HEDP)

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 9-14
Author(s):  
RICHARD BERRY ◽  
YUJUN SUN ◽  
CORINNE LUTHE
Keyword(s):  
Calcium Carbonate ◽  
Rate Increase ◽  
Black Spruce ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Diphosphonic Acid ◽  
Kraft Cooking ◽  
Effective Additive ◽  
Cooking Conditions

Three hardwoods (aspen, maple, and birch) and one softwood (black spruce) were pulped under standard kraft cooking conditions with and without hydroxyethylidene diphosphonic acid (HEDP). The H factor required to give a kappa number of 15 for the aspen furnish was decreased from 1,100 to 650 by adding 0.1% HEDP on wood. Significantly smaller rate increases were observed with birch and maple, and no rate increase was observed with the softwood furnish. When aspen and black spruce chips were impregnated with calcium, it was found that aspen delignification was retarded while there was no effect on black spruce. HEDP, therefore, appears to work by removing calcium which, in hardwoods, causes lignin to be strongly bonded to the fiber. Adding carbonate to the pulping liquor showed that carbonate has the same effect as HEDP by removing calcium as insoluble calcium carbonate (CaCO3). These observations lead to the conclusion that HEDP is not an effective additive, even for hardwoods, when sufficient carbonate is present.

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.

Application of Chelating Agents as Cooking Aids in Bamboo Pulping

2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Strength

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.

scholarly journals Lipid and lignin composition of woods from different eucalypt species

Holzforschung ◽  
2007 ◽  
Vol 61 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Jorge Rencoret ◽  
Ana Gutiérrez ◽  
José C. del Río
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Kraft Pulping ◽  
Medium Length ◽  
Eucalypt Species ◽  
Kraft Cooking ◽  
Lignin Composition ◽  
G Ratio ◽  
Cooking Conditions

Abstract The lipid and lignin compositions of woods from the eucalypt species Eucalyptus globulus, E. nitens, E. maidenii, E. grandis, and E. dunnii have been characterized. The lipid composition was analyzed by GC and GC/MS using short- and medium-length high-temperature capillary columns, which allowed the detection of intact high-molecular-weight compounds. Similar lipid compositions were observed in all eucalypt woods, which were dominated by sitosterol, sitosterol esters and sitosteryl 3β-D-glucopyranoside. These substance classes are mainly responsible for pitch deposition during kraft pulping of eucalypt wood. However, some quantitative differences were found in the abundance of different lipid classes, with wood from E. globulus containing the lowest amounts of these pitch-forming compounds. The lignins of all eucalypt woods were analyzed in situ (without previous isolation) by pyrolysis-GC/MS. A predominance of syringyl (S) over guaiacyl (G) lignin units was observed and the S/G ratio was in the range from 2.7 to 4.1. E. globulus wood had the highest S/G ratio, a finding that, together with its low lignin content, explains its easy delignification under kraft cooking conditions.

Kraft pulping and bleaching of Eichhornia crassipes (Mart.) Solms (water hyacinth)

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 ◽  
...  
Keyword(s):  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Inorganic Elements ◽  
Wood Fibers ◽  
Pulp Bleaching ◽  
Cellulosic Pulp ◽  
Unbleached Pulp

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.

Application of Diethylene Triamine Penta Methylene Phosphonic Acid in Bamboo Pulping

2012 ◽  
Vol 550-553 ◽  
pp. 3331-3334
Author(s):  
Hong Xia Gao
Keyword(s):  
Phosphonic Acid ◽  
Kappa Number ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Properties

The effect of Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp properties are optimal when DTPMPA dosage is 0.4%. The optimal properties are as follows: the kappa number is 16.4, brightness is 37.8%, and the screened yield is 41.9%.

Voltammetric analysis of the bleachability of softwood kraft pulps

Holzforschung ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 581-587 ◽  
Author(s):  
Robert Bourbonnais ◽  
Loredana Valeanu ◽  
Michael G. Paice
Keyword(s):  
Chlorine Dioxide ◽  
Acid Content ◽  
Black Spruce ◽  
Kappa Number ◽  
Western Hemlock ◽  
Kraft Pulps ◽  
Residual Lignin ◽  
Redox Mediators ◽  
Voltammetric Analysis ◽  
Hexenuronic Acid

Abstract Kraft and oxygen delignified pulps with various kappa numbers were prepared from black spruce and western hemlock chips. The bleachability (ratio of kappa number decrease to chlorine dioxide applied) of the different pulps at the same kappa number varied with both wood furnish and delignification process. Thus, unbleached kappa number alone is not a reliable indicator of bleachability for these pulps. This may be due in part to the variable hexenuronic acid content of the pulps; those with higher ratio of hexenuronic acid content to kappa number (HexA/kappa) are harder to bleach. Voltammetric analysis of the same kraft pulps in the presence of redox mediators was found to measure both the content and reactivity of residual lignin. Peak current ratios of redox mediators correlated with pulp bleachability for all pulps. These ratios may therefore provide a more accurate prediction of bleachability than unbleached kappa number.

Relationship between Viscosity and Recycling of Dendrocalamus giganteus Munro Pulp

2012 ◽  
Vol 518-523 ◽  
pp. 604-607
Author(s):  
Jie He
Keyword(s):  
Low Temperature ◽  
Water Retention ◽  
High Viscosity ◽  
Kraft Pulping ◽  
Water Retention Value ◽  
Dry Heat ◽  
Pulp Viscosity ◽  
Kraft Cooking ◽  
The Relationship ◽  
Dendrocalamus Giganteus

In this paper, two groups of Dendrocalamus giganteus Munro pulp were obtained from conventional kraft pulping (the maximum pulping temperature was 165°C) and low-temperature kraft pulping (the maximum pulping temperature was only 135°C) under the premise of kappa number of about 17, and the viscosity of them were 1240 mL•g-1 and 1426 mL•g-1 respectively. Then the handsheets was treated with dry heat aging and the simulation of pulp recycling was investigated. In addition, the relationship between the pulp viscosity and recycling times of pulp were studied. The results showed that the viscosity and water retention value of two groups of pulp decreased with increasing of recycling times. However, the recycling characteristic of the pulp with high viscosity from low-temperature kraft cooking was better.

scholarly journals Evaluation of Rhododendron Luteum and Rhododendron Ponticum in Pulp and Paper Production

2020 ◽  
Vol 71 (4) ◽  
pp. 365-370
Author(s):  
Emre Birinci ◽  
Ahmet Tutuş ◽  
Mustafa Çiçekler
Keyword(s):  
Physical Properties ◽  
Kappa Number ◽  
Pulp And Paper ◽  
Raw Material ◽  
Paper Properties ◽  
Paper Production ◽  
Rhododendron Ponticum ◽  
Breaking Length ◽  
Pulp Properties ◽  
Cooking Conditions

In this study, Rhododendron luteum and Rhododendron ponticum were evaluated as raw material for pulp and paper production. 12 different sodium borohydride (NaBH4) added cooking trials were performed for each sample and kraft method was used for pulp production. Pulp properties, such as yield, kappa number and viscosity, and physical properties, such as breaking length and burst index, were determined for each trial. Besides, the effects of active alkali and NaBH4 on the pulp and paper properties were also examined. Optimum cooking conditions were obtained by using 18 % active alkali for NaBH4-free cooking experiments and 0.5 % NaBH4 and 18 % active alkali for NaBH4-added cooking experiments. In NaBH4-added pulping condition, the screened yield, kappa number and viscosity of R. luteum were found to be 43.4 %, 40.1 and 949 cm3/g1, respectively. The respective values for R. ponticum were 41.9 %, 44.5 and 885 cm3/g1. The screened yields of R. luteum and R. ponticum increased by about 2.8 % and 5.3 %, respectively, with 5 % addition of NaBH4 compared to NaBH4-free cooking experiments. Furthermore, with the addition of NaBH4, the kappa numbers decreased while the viscosity increased. The physical properties of the produced papers were also improved by using NaBH4 in cooking liquor. According to the obtained results, it was found that R. luteum and R. ponticum species can be evaluated for pulp and paper production.

scholarly journals Formic Acid Pulping of Bagasse

1970 ◽  
Vol 41 (3) ◽  
pp. 245-250 ◽  
Author(s):  
M Sarwar Jahan
Keyword(s):  
Formic Acid ◽  
Acid Concentration ◽  
Strength Properties ◽  
Kappa Number ◽  
Cooking Time ◽  
Pulp Yield ◽  
Cooking Conditions

Atmospheric formic acid pulping of bagasse was done with varying formic acid concentration and cooking time. Pulp yield and kappa number decreased with increasing formic acid concentration or cooking time. The optimal cooking conditions were 90 % formic acid and 90 min of cooking at 95°C. The pulp yield at this condition was 44.4 % and kappa number 26.1. The strength properties were acceptable in formic acid pulping of bagasse. Addition of H2SO4 catalyst in formic acid degraded carbohydrate, resulting lower pulp yield and inferior strength properties. The strength properties were improved slightly after bleaching. Bangladesh J. Sci. Ind. Res. 41(3-4), 245-250, 2006

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