Bleached kraft pulp production from Pinus tecunumanii (Eguiluz e Perry)

The use of 12-year-old Pinus tecunumanii (Eguiluz e Perry) grown in Colombia was evaluated for bleached kraft pulp production. Kraft pulps of kappa number 30 ± 1 were produced, and oxygen delignified and bleached to 90% ISO with ECF processes. The bleached pulps produced under optimum conditions were evaluated with regard to their strength properties. Pinus tecunumanii wood required low effective alkali charge to reach the desired kappa number and the unbleached pulp showed high oxygen delignification efficiency and bleachability when a OD(EO)DED sequence was used. The bleached pulps presented good physical-mechanical properties, which are comparable to those obtained with more traditional pines such as Pinus taeda and Pinus radiata. The results demonstrate that this tropical pine species is a suitable raw material for bleached kraft pulp production

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Changes in the lignin-carbohydrate complex in softwood kraft pulp during kraft and oxygen delignification

Holzforschung ◽

10.1515/hf.2004.114 ◽

2004 ◽

Vol 58 (6) ◽

pp. 603-610 ◽

Cited By ~ 48

Author(s):

Martin Lawoko ◽

Rickard Berggren ◽

Fredrik Berthold ◽

Gunnar Henriksson ◽

Göran Gellerstedt

Keyword(s):

Kraft Pulp ◽

Kappa Number ◽

Kraft Pulps ◽

Residual Lignin ◽

Oxygen Delignification ◽

Number Range ◽

Morphological Aspects ◽

Carbohydrate Complex ◽

Softwood Kraft Pulp ◽

Hydrolysis Of

Abstract Three kraft pulps in the kappa number range between 50 and 20 and the same pulps oxygen-delignified to similar lignin contents (kappa approximately 6) were analyzed for lignin-carbohydrate complexes (LCC) by a method based on selective enzymatic hydrolysis of the cellulose, and quantitative fractionation of the LCC. Between 85 and 90% of residual lignin in the unbleached kraft pulp and all residual lignin in the oxygen-delignified pulps were isolated as LCC. Three types of complexes were found; viz., xylan-lignin, glucomannan-lignin-xylan and glucanlignin complexes. After pulping to a high kappa number, most of the residual lignin was linked to xylan. Different delignification rates were observed so that most of the residual lignin was linked to glucomannan when the pulping was extended to a low kappa number. With increasing degree of oxygen delignification, a similar trend in the delignification rates of LCC was observed so that the residual lignin was increasingly linked to glucomannan. Complex LCC network structures seemed to be degraded into simpler structures during delignification. The differences in delignification rates are discussed with reference to the solubility properties and structural differences of LCC, and to morphological aspects of the pulp.

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Technological evaluation of Pinus maximinoi wood for industrial use in kraft pulp production

TAPPI Journal ◽

10.32964/tj20.8.501 ◽

2021 ◽

Vol 20 (8) ◽

pp. 501-508

Author(s):

MARINA ULIAN COELHO ◽

FRANCIDES GOMES DA SILVA, JR. ◽

FLAVIANA REIS MILAGRES ◽

SILVANA MEISTER SOMMER ◽

CARLOS AUGUSTO SOARES DO AMARAL ◽

...

Keyword(s):

Process Analysis ◽

Black Liquor ◽

Basic Density ◽

Kraft Pulping ◽

Kappa Number ◽

Raw Material ◽

Bulk Property ◽

Oxygen Delignification ◽

Old Trees ◽

Pulp Production

This study characterized Pinus maximinoi wood and evaluated its performance for pulp production. Samples of Pinus taeda wood were used as reference material. For both species, wood chips from 14-year-old trees were used for the technological characterization, pulping, bleaching process analysis, and pulp properties. A modified kraft pulping process was carried out targeting kappa number 28±5% on brownstock pulp. The bleaching sequence was applied for bleached pulp with final brightness of 87±1 % ISO. Refinability and resistance properties were measured in the bleached pulps. Compared to P. taeda wood, P. maximinoi showed slightly higher basic density (0.399 g/cm³) and higher holocellulose (64.5%), lignin (31.1%), and extractives content (4.5%), along with lower ash content (0.16%). P. maximinoi tracheids showed greater wall thickness (6.4 µm) when compared to P. taeda tracheids. For the same kappa number, P. maximinoi and P. taeda resulted in similar screened yield, with an advantage observed for P. maximinoi, which resulted in lower specific wood consumption (5.281 m³/o.d. metric ton), and lower black liquor solids (1.613 metric tons/o.d. metric ton). After oxygen delignification, P. maximinoi pulp showed higher efficiency on kappa reduction (67.2%) and similar bleaching chemical demand as P. taeda pulp. Compared to P. taeda pulps, the refined P. maximinoi pulps had similar results and the bulk property was 10% higher. Results showed that P. maximinoi is an interesting alternative raw material for softwood pulp production in Brazil.

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EFEKTIVITAS BERBAGAI INDIKATOR PENGGILINGAN UNTUK MEMPREDIKSI KUALITAS KERTAS

JURNAL SELULOSA ◽

10.25269/jsel.v1i02.22 ◽

2016 ◽

Vol 1 (02) ◽

Author(s):

Hana Rachmanasari ◽

Taufan Hidayat

Keyword(s):

Kraft Pulp ◽

Wood Pulp ◽

Strength Properties ◽

Raw Material ◽

Fiber Morphology ◽

Mechanical Pulp ◽

Chemical Pulp ◽

Bleached Kraft Pulp ◽

Drainage Rate

The experiments of refining have been done using PFI mill and Beater, at 300 mL CSF of freenessas fixed parameters. Research was aims to determine the effective indicators of refining to predict the quality of the paper. The raw material used were wood pulp, non wood pulp, chemical pulp, mechanical pulp, Leaf Bleached Kraft Pulp (LBKP) and Needle Bleached Kraft Pulp (NBKP). The parameters which analyzed for each equipments were fibers classification, fiber morphology, dimensions of its derivatives and as the value of the drainage rate. The strenght of handsheets formed from the fibers were tested including tensile, bursting, and tearing strength. According to the results of correlation analysis, the most effective and sensitive indicators of refining towards strength properties of paper, in the wo different refining methods, is the felting power slenderness with correlation values above 0.8.Key words : refining, fiber classification, fiber morphology, the strength properties, correlation valueABSTRAKTelah dilakukan percobaan penggilingan menggunakan PFI mill dan Valley Beater, pada freeness 300 mL CSF sebagai parameter tetap. Penelitian ini bertujuan untuk mengetahui beberapa indikator penggilingan yang efektif untuk memprediksi kualitas kertas. Bahan baku terdiri dari pulp kayu, pulp non kayu, pulp kimia, pulp mekanis, pulp kayudaun dan pulp kayujarum. Parameter yang dianalisa untuk masing-masing hasil penggilingan adalah klasifikasi serat, morfologi serat dan dimensi turunannya serta nilai laju drainase. Selanjutnya dilakukan uji sifat kekuatan yang meliputi ketahanan tarik, retak dan sobek. Berdasarkan hasil analisa korelasi terhadap data penelitian, indikator penggilingan yang paling efektif dan sensitif terhadap sifat kekuatan kertas pada dua metode penggilingan berbeda adalah kelangsingan dengan nilai korelasi di atas 0,8.Kata kunci : penggilingan, klasifikasi serat, morfologi serat, sifat kekuatan, nilai korelasi

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Electrochemical Delignification Mediated with Violuric Acid and Subsequent Bleaching of Poplar Kraft Pulp

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.201-203.2854 ◽

2011 ◽

Vol 201-203 ◽

pp. 2854-2857 ◽

Cited By ~ 3

Author(s):

Fan Gong Kong ◽

Chen Fu Li ◽

Shou Juan Wang ◽

Shi Yu Fu

Keyword(s):

Kraft Pulp ◽

Alkali Treatment ◽

Kappa Number ◽

Kraft Pulps ◽

Optimum Conditions ◽

New Methods ◽

Violuric Acid

The electrochemically mediated delignification （EM）is one of new methods for pulp delignification and bleaching. In this paper, the electrochemical delignification mediated with violuric acid (VIO) of the kraft pulps were carried out. The results showed that VIO was suitable mediator for the electrochemical delignification of poplar kraf pulp. At the optimum conditions, the Kappa number was reduced from 17.4 to 11.7 and viscosity was decreased from 1144cm3/g to 1059cm3/g. The alkali treatment after EM could further reduce Kappa number and increase brightness of electrochemical-VIO treated pulp. The Kappa number of pulp treated with EME could be reduced to 8.9 with the delignification rate of 48.8% and viscosity only decreased to 1065 cm3/g. The brightness of EM E treated pulp increased from original 39.2%ISO to 50.7%. The EM treated pulps could be bleached to 80%ISO with the subsequent QP or EQP sequences at 2.0% of H2O2 charge.

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Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽

10.32964/tj12.11.49 ◽

2013 ◽

Vol 12 (11) ◽

pp. 49-53 ◽

Cited By ~ 1

Author(s):

CHRISTINE CHIRAT ◽

LUCIE BOIRON ◽

DOMINIQUE LACHENAL

Keyword(s):

Carbon Content ◽

Acid Hydrolysis ◽

13C Nmr ◽

Kraft Lignin ◽

Kappa Number ◽

Hydroxyl Groups ◽

Kraft Pulps ◽

Quaternary Carbon ◽

Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

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Deep eutectic solvent delignification: Impact of initial lignin

BioResources ◽

10.15376/biores.12.4.7301-7310 ◽

2017 ◽

Vol 12 (4) ◽

pp. 7301-7310

Author(s):

Veronika Majová ◽

Silvia Horanová ◽

Andrea Škulcová ◽

Jozef Šima ◽

Michal Jablonský

Keyword(s):

Lactic Acid ◽

Oxalic Acid ◽

Lignin Content ◽

Choline Chloride ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Kappa Number ◽

Kraft Pulps ◽

Oxygen Delignification ◽

Detailed Understanding

This study aimed to resolve the issue of the lack of detailed understanding of the effect of initial lignin content in hardwood kraft pulps on pulp delignification by deep eutectic solvents. The authors used Kappa number of the concerned pulp, intrinsic viscosity, and selectivity and efficiency of delignification as the parameters of the effect. The pulp (50 g oven dry pulp) was treated with four different DESs systems based on choline chloride with lactic acid (1:9), oxalic acid (1:1), malic acid (1:1), and system alanine:lactic acid (1:9); the results were compared to those reached by oxygen delignification. The results showed that the pulp with a higher initial lignin content had a greater fraction of easily removed lignin fragments.

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Strong paper from spruce CTMP – Part II: Effect of pressing at nip press temperatures above the lignin softening temperature

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-3009 ◽

2018 ◽

Vol 33 (1) ◽

pp. 142-149 ◽

Cited By ~ 1

Author(s):

Sven Norgren ◽

Gunilla Pettersson ◽

Hans Höglund

Keyword(s):

Compression Strength ◽

Kraft Pulp ◽

Softening Temperature ◽

Strength Properties ◽

Kraft Pulps ◽

Cationic Starch ◽

Tensile Index ◽

Very High

Abstract The main objective of the current study was to demonstrate that it is possible to enhance strength properties of sheets from spruce HT-CTMP and CTMP furnishes up to the same level as is common on sheets from softwood kraft pulps by changing conditions in papermaking. To achieve that, sheets of spruce HT-CTMP and CTMP were consolidated at densities close to that of the reference bleach kraft pulp by pressing at press nip temperatures well above the tack and softening temperatures of lignin. On sheets from spruce CTMP (CSF 420 ml), where the fibers were surface treated with cationic starch, it was possible to reach tensile index at the same level as on sheets from the untreated reference kraft pulp. The compression strength (SCT) of CTMP and HT-CTMP sheets, which were achieved at the highest press nip temperature (200 °C) in the study, was equal to or higher than that of the reference kraft pulp sheets. The results show that there is a great yet unexploited potential in papermaking from spruce HT-CTMP and CTMP furnishes, which could be utilized in manufacturing of products where very high requirements upon strength is demanded.

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MEA/water/AQ-pulping of wheat straw

Holzforschung ◽

10.1515/hf.2009.110 ◽

2009 ◽

Vol 63 (5) ◽

Cited By ~ 4

Author(s):

Sahab Hedjazi ◽

Othar Kordsachia ◽

Rudolf Patt ◽

Andreas Kreipl

Keyword(s):

Wheat Straw ◽

Total Yield ◽

Strength Properties ◽

Kappa Number ◽

Chemical Recovery ◽

Oxygen Delignification ◽

Cooking Temperature ◽

Recovery System ◽

Environmentally Sound ◽

High Yields

Abstract Annual plant pulping is faced with serious challenges. Traditional pulping processes with bleaching in chlorine based sequences and without appropriate chemical recovery system cannot be tolerated anymore. Alternative pulping processes with non-conventional chemicals, such as organic solvents, e.g., monoethanolamine (MEA), might be suited for an environmentally sound process with a closed mill system. Thus, pulping of wheat straw with MEA as the main delignifying agent was investigated in comparison to soda and soda/AQ pulps as references. The main focus was placed on reduction of the cooking temperature in order to avoid heat-induced MEA degradation. The temperature was reduced stepwise from 165°C to 130°C. At 150°C, a sufficient delignification was achieved. MEA was partly substituted by water and the resulting decrease of the delignification rate could be compensated by addition of anthraquinone (AQ). After optimization of the process, a pulp with a kappa number of 17 was obtained at a total yield of 56% based on o.d. straw. This pulp was selected for bleaching. Both, O/Q/OP/DQ/P (“ECF light”) and O/Q/OP/ZQ/P (TCFZ) bleaching were applied. NaOH was substituted by MEA as alkali source in the oxygen delignification stage. Up to 50% delignification rate was achieved under these moderate conditions. In the ECF light bleaching sequence, a brightness of 80% ISO was reached at a kappa number level below 3. In TCFZ bleaching, an even somewhat higher brightness was achieved at a kappa number level below 1. A yield of fully bleached screened pulp of around 50% (based on o.d. straw) was obtained. The strength properties of the MEA pulp were improved after bleaching. ECF bleaching resulted in slightly better pulp strengths than the TCFZ alternative. MEA forms in combination with water and AQ a very selective pulping system providing effective delignification and maintaining extremely high yields. MEA/water/AQ pulping should be regarded as a serious, environmentally friendly alternative to soda or soda/AQ pulping to produce high-quality pulp from wheat straw.

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Pre-bleaching of kraft acacia pulp

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-0082 ◽

2019 ◽

Vol 34 (2) ◽

pp. 165-172 ◽

Cited By ~ 1

Author(s):

Moinul Haque ◽

Moumita Nanjiba ◽

M. Sarwar Jahan ◽

M. A. Quaiyyum ◽

M. Zahangir Alam ◽

...

Keyword(s):

Acacia Mangium ◽

Kappa Number ◽

Acacia Auriculiformis ◽

Kraft Pulps ◽

Oxygen Delignification ◽

Acid Pretreatment ◽

Acacia Hybrid ◽

Pre Treatment ◽

Hexenuronic Acid ◽

Peroxyformic Acid

Abstract Kraft pulps from acacia hybrid, Acacia mangium of 8 years old and Acacia auriculiformis of 6, 8 and 10 years old were pre-treated with oxygen, peroxyformic acid and acid treatment prior to bleaching. The kappa number reduction was 52–63 % by oxygen delignification, 31–35 % by peroxyformic acid (PFA) pre-treatment and 11–13 % by acid pre-treatment. Oxygen delignified pulp required less chlorine dioxide charge to reach target brightness. At the consumption of 30 kg ClO2/ton of pulp, the pulp brightness reached to 65–71 % for the untreated pulp, 81–85 % for the oxygen delignified pulp, 81–82 % for the PFA treatment and 79–80 % for acid pre-treated pulp. COD load in bleached effluent was much lower in oxygen delignified pulp. Cold alkali extraction of unbleached and oxygen delignified pulps was also carried out with varying alkali charge to remove hexenuronic acid (HexA) from the pulp. Xylan removal from the pulp was insignificant and resulted in no removal of HexA. Acid pretreatment removed 55.7 % to 17.8 % HexA from acacia hybrid, 57.5 % to 16.3 % from A. auriculiformis of 10 years and 58.6 % to 20.1 % from A. auriculiformis of 6 years old, resulting in improved final pulp brightness.

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Research on Production of Hand Towel from the Poplar Extruding Mechanical Pulp (EMP)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.3253 ◽

2012 ◽

Vol 550-553 ◽

pp. 3253-3257

Author(s):

Xian Qi Sun ◽

Chuan Shan Zhao ◽

Hui Rong Yang

Keyword(s):

Kraft Pulp ◽

Lower Cost ◽

Raw Materials ◽

Raw Material ◽

Public Places ◽

Mechanical Pulp ◽

Tissue Paper ◽

Chemical Pulp ◽

Bleached Kraft Pulp ◽

High Level

Hand towel is one kind of disposable tissue paper which has characteristic of soaking up water quickly and lower cost. It becomes increasingly popularity in families, at work, and public places. There are many kinds of raw materials to produce hand towel according to its level. Some researches showed that bleached chemical pulp could be partially used to the production of hand towel and some other household paper. In this study, some kinds of raw material which be used to produce hand towel were analyzed and trying to looking for new one. Poplar Extruding Mechanical Pulp (EMP) had characteristics of long fiber, high level of strength and brightness. Different ratio of poplar EMP and certain Bleached Kraft Pulp were tested to make hand towel. The effects of poplar EMP on whiteness, tensile strength, bulkiness, absorbability were discussed. The results showed that characteristic targets of hand towel made from poplar EMP and Bleached Kraft Pulp met the quality requirements of GBT22455-2009 and satisfied the high-end hand towel. The new hand towel had lower cost, higher stiffness and higher bulkiness. It was feasible from the technique and economy point.

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