• Title/Summary/Keyword: 크라프트

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Studies on the Pulping Characteristics of Larchwood (Larix leptolepis Gordon) by Alkaline Process with Additives (첨가제(添加劑) 알칼리 법(法)에 의한 일본 잎갈 나무의 펄프화(化) 특성(特性)에 관(關)한 연구(硏究))

  • Lim, Kie-Pyo;Shin, Dong-Sho
    • Journal of the Korean Wood Science and Technology
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    • v.7 no.2
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    • pp.3-30
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    • 1979
  • Larch ($\underline{Larix}$ $\underline{leptolepis}$ GORDON), one of the major afforestation species in Korea in view of its growing stock and rate of growth, is not favored as a raw material for pulp due to its low yield of pulp and difficulties with bleaching arising from the high content of extractives in wood, and the high heartwood ratio and the active phenolics, respectively. The purpose of this study is to investigate the characteristics of firstly pulping with various additives of cellulose protector for the yield of pulp, and secondly bleaching with oxygen for chlotination-alkali extraction of five stage-sequence to reduce chlorine compounds in bleaching effluents. The kraft cooking liquor for five age groups of larchwood was 18 percent active alkali with 25 percent sulfidity and 5 : 1 liquor-to-wood ratio, and each soda liquor for sap-and heart-wood of the 15-year-old larchwood was 18 percent alkali having one of the following cellulose protectors as the additive; magnesium sulfate ($MgSO_4$, 2.5%), zinc sulfate ($ZnSO_4$, 2.5%), aluminium sulfate ($Al_2(SO_4)_3$, 2.5%), potasium iodide (KI, 2.5%), hydroquinone (HQ, 2.5%), anthraquinone (AQ, 0.1%) and ethylene diamine (EDA, 2.5%). Then each anthraquinone-soda liquor for the determination of suitable cooking condition was the active alkali level of 15, 17 and 19 percent with 1.0, 0.5 and 0.1 percent anthraquinone, respectively. The cooking procedure for the pulps was scheduled to heat to 170$^{\circ}C$ in 90 minutes and to cook 90 minutes at the maximum temperature. The anthraquinone-soda pulps from both heartwood and sapwood of 15-year-old larchwood prepared with 0.5 percent anthraquinone and 18 percent active alkali were bleached in a four-stage sequency of OCED. (O: oxygen bleaching, D: chlorine dioxide bleaching and E: alkali extraction). In the first stage oxygen in atmospheric pressure was applied to a 30 percent consistency of pulp with 0.1 percent magnesium oxide (MgO) and 3, 6, and 9 percent sodium hydroxide on oven dry base, and the bleached results were compared pulps bleached under the conventional CEDED (C: chlorination). The results in the study were summarized as follows: 1. The screened yield of larch kraft pulp did not differ from particular ages to age group, but heartwood ratio, basic density, fiber length and water-extractives contents of wood and the tear factor of the pulp increased with increasing the tree age. The total yield of the pulp decreased. 2. The yield of soda pulp with various chemicals for cellulose protection of the 15-year-old larchwood increased slightly more than that of pure soda pulp and was slightly lower than that of kraft pulp. The influence of cellulose protectors was similar to the yield of pulps from both sapwood and heartwood. The effective protectors among seven additives were KI, $MgSO_4$ and AQ, for which the yields of screened pulp was as high as that of kraft pulp. Considering the additive level of protector, the AQ was the most effective in improving the yield and the quality of pulp. 3. When the amount of AQ increased in soda cooking, the yield and the quality of the pulp increased but rejects in total yield increased with decreasing the amount of active alkali from 19 to 15 percent. The best proportion of the AQ seemed to be 0.5 percent at 17 percent active alkali in anthraquinone-soda pulping. 4. On the bleaching of the AQ-soda pulp at 30 percent consistency with oxygen of atomospheric pressure in the first stage of the ODED sequence, the more caustic soda added, the brighter bleached pulp was obtained, but more lignin-selective bleaching reagent in proportion to the oxygen was necessary to maintain the increased yield with the addition of anthraquinone. 5. In conclusion, the suitable pulping condition for larchwood to improve the yield and quality of the chemical pulp to the level for kraft pulp from conventional process seemed to be. A) the selection of young larchwood to prevent decreasing in yield and quality due to the accumulation extractives in old wood, B) the application of 0.5 percent anthraquinone to the conventional soda cooking of 18 percent active alkali, and followed, C) the bleaching of oxygen in atmospheric pressure on high consistency (30%) with 0.1 percent magnesium oxide in the first stage of the ODED sequence to reduce the content of chlorine compounds in effluent.

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Kraft Pulp Properties Made of Forest Bioamss from Forest Management Operation (숲가꾸기 산물에 의한 크라프트 펄프의 적성 연구)

  • Park, Hyeon-Jin;Kim, Cheol-Hwan;An, Byeong-Il;Lee, Ji-Yeong;Sheikh, MD Mominul Islam;Yeasmin, Shabina;Gwak, Hye-Jeong;Kim, Seong-Ho;Kim, Gyeong-Cheol
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.04a
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    • pp.131-138
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    • 2011
  • Currently, many forest residues have been generated by the National Forest Management Operation. Unfortunately, most of the forest residues are supposed to be used as raw materials for burning fuels like wood pellets. Even though the forest biomass must be effectively used for making high value-added products, they may be subject to disposable raw materials for wood pellets. Wood pellets are regarded as burning fuels with less contribution to the decrease in carbon gas emission, compared to raw materials for kraft pulps. In this study, we studied whether or not forest biomass mixed with various ages and, species could be used as raw materials for kraft pulps.

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Study of Kraft Pulp Properties for Kraft Pulping from Forest Biomass (산림바이오매스의 크라프트 펄프화를 위한 펄프 적성 연구)

  • Park, Hyeon-Jin;Kim, Cheol-Hwan;Lee, Ji-Yeong;Sheikh, Mominul Islam;Kim, Seong-Ho;Kim, Gyeong-Cheol;Sim, Seong-Ung;Jo, Hu-Seung
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.10a
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    • pp.143-149
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    • 2011
  • In recent, many forest residues have been generated by the National Forest Management Operation. Unfortunately, most of the forest residues are supposed to be used as raw materials for burning fuels like wood pellets. In this study, we investigated whether or not this forest biomass mixed in various ages and species could be used as raw materials for making kraft pulps in a view of optical properties.

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A Comparative Study on Green Liquor Pre-Pulping Extraction of Mixed Hardwood Chips (혼합 하드우드 칩으로부터 녹액(Green Liqour)선-펄핑추출 공정에 관한 연구)

  • Um, Byung-Hwan
    • Korean Chemical Engineering Research
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    • v.51 no.5
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    • pp.561-567
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    • 2013
  • Mixed hardwood chips were pre-pulping extracted with green liquor prior to kraft pulping in order to recover hemicelluloses for use as biofuels. This green liquor solution containing mainly sodium sulfide and sodium carbonate was applied at different alkali charges (expressed as $Na_2O$) of 0, 1, 3, and 5% on dry wood weight. The extractions were performed at $160^{\circ}C$ for residence times ranging from about 1-2 h to determine the effect of extraction severity on composition of the pre-pulping extract. The severity of hemicellulose extraction time and green liquor charge controls the concentration of acetic acid and monosaccharide sugars available for downstream processing, the accumulation of degradation products such as organic acids and furans in the extract. As the alkali charge was increased, the amount of acetate side chains on the hemicelluloses and the dissolved lignin in the extract increased but the carbohydrate and sugars in the extract decreased appreciably. Hot water extraction (0% alkali addition) released the greatest amount of carbohydrates, up to 29.80 g/L measured as component sugars, but resulted in the greatest decrease in pulp yield. Meanwhile, pre-pulping extraction with 3% green liquor increased the pulp yield while greatly reducing the component sugars to 7.08 g/L. Fundamental data obtained in this study will allow selection of optimum hemicellulose extraction conditions for integrating the extraction operation into the Kraft pulping process.

The analysis of products from base-catalyzed depolymerization of kraft lignin (크라프트 리그닌의 염기 촉매 분해(BCD)에 의한 부산물의 조성 분석)

  • Kim, Seok Ju;Kim, Yong Sik
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.6
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    • pp.583-593
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    • 2013
  • The based-catalyzed depolymerization (BCD) of kraft lignin isolated from black liquor which the chemical pulping of a mixture of various Southeast Asia hardwood chips was carried out in a batch reactor in the presence of different NaOH concentrations with supercritical methanol. The S:G ratio of the kraft lignin determined by pyrolysis-GC/MS analysis turned out roughly 1.4:1 and main products were vanillic acid, syringol and 3-methoxy catechol. The diethyl ether extracts as phenolic monomers from BCD reaction were produced similar yield among different NaOH concentrations. The 21 compounds were identified by GC/MS analysis in all experiments and major products were catechol, 3-methoxycatechol, 4-methylcatechol, syringol and isovanillic acid. However, it had been shown to be different monomer contents depending on the dosage of NaOH. Catechol, 4-methylcatechol and 3-methoxycatechol were shown to be the dominant monomer from BCD reaction using 7.5 and 3.25% of NaOH concentration whereas syringol, isovanillic acid, 3-methoxycatechol and 4-methylcatechol were determined to be the most typical products under the condition of 1.63% NaOH.

Effects of Kneading Concentration on Characteristics of HwBKP Fibers (니딩 처리 시 지료농도에 따른 활엽수표백크라프트펄프의 섬유특성 변화)

  • Seo, Ji-Hye;Choi, Kyoung-Hwa;Cho, Byoung-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.4
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    • pp.54-59
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    • 2015
  • In this study, effects of kneading concentration on characteristics of hardwood bleached kraft pulp (HwBKP) fibers were elucidated. A laboratory two-shaft kneader was utilized for kneading. Kneading concentration was varied in the range of 15-30% (w/w) and the number of kneading treatment was adjusted between 0 and 6 passes. It was found that kneading concentration influenced fiber characteristics. At 15% of pulp concentration, fiber length slightly increased with increasing the number of kneading passes, while other morphological properties such as fiber width and curl decreased: fiber straightening occurred. In addition, the increase in WRV and the decrease in CSF were the largest at 15% kneading concentration, meanings that fibrillation mainly occurred. In contrast, at higher kneading concentration exceeding 20%, fiber deformation like curl was mainly occurred. Also, at kneading concentration of 20% and 30%, fiber length decreased with the number of kneading passes while other morphological properties such as fiber width, and WRV increased. Severe fiber entanglement was found at 30% kneading, which shall be removed during papermaking.

Simulation for Prediction of Moisture Changes during Storage of Packaged Corn Starch (옥수수 전분의 저장중 수분 변화 예측을 위한 시뮬레이션)

  • Kim, Byeong-Sam;Park, Moo-Hyun;Park, Noh-Hyun;Jo, Jin-Ho
    • Korean Journal of Food Science and Technology
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    • v.22 no.4
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    • pp.473-478
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    • 1990
  • A computer-aided simulation technique was selected to predict the gain or loss of moisture in corn starch packaged with gas and moisture permeable materials under various conditions. Water activity and moisture content of corn starch was predicted by computer program at various conditions. A linear relationship was showed between water activity and equilibrium moisture content at the range of $A_w$ 0.332 to 0.90 and simulated values obtained by the proposed model was given to a dose approximation with the observed values.

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Studies on Bonding Characteristics of Plywood by Kraft Black Liquor and Surface Activators (크라프트펄프 폐액(廢液)과 표면산화제(表面酸化劑)를 이용(利用)한 합판(合板)의 접착특성(接着特性)에 관(關)한 연구(硏究))

  • Chung, In-Ju;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.3
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    • pp.5-16
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    • 1988
  • This experiment was executed to investigate the effect of activation of veneer surface by oxidizing agents, hydrogen peroxide and nitric acid, on bonding characteristics of Malas(Homalium foetidum Benth) plywood, in which the effects of these oxidizing agents amount, pretreatment time, and pressing time and temperatue on shear strength of the plywood were examined and discussed. In this research the activation of veneer surface by oxidants was effective in raising shear strength but the difference in shear strength was not observed between hydrogen peroxide and nitric acid treatment. Hydrogen peroxide treatment, however, seemed to be more profitable to industrial application because of its lower concentration and easier handling than nitric acid. The bonding method by lignin-phenol adhesive through surface activation revealed inferior shear strength to phenol- and urea-formaldehyde adhesive but superior water resistance to urea-formaldehyde adhesive and this bonding method, in addition, have the advantage of lower cost compared with phenol-formaldehyde adhesive, Therefore, this bonding method by lignin-phenol adhesive through surface activation seemed to economical in manufacturing of water-resistant wood panel materials in future.

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Changes in Extractives of Blue Stained Woods and Its Pulping (청변목재의 추출물함량 변화와 펄프화특성)

  • Cho, Nam-Seok;Lee, Jong-Kyu;Jeong, Sun-Wha;Pashenova, Natalia;Hop, P.T.B.
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2003.11a
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    • pp.1-8
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    • 2003
  • 변색목재의 화학적 성질을 조사한 결과, 처리전.후의 유기용매추출물 함량에 있어서 소나무재 및 리기다소나무재 공히 노화 및 변색균처리포 그 함량이 낮아지는 결과를 나타냈는바, fatty acids와 sterols 은 3주간 노화처리로 10.6-11.2%, 변색균처리로 36-41.1%의 높은 감소율을 나타냈다. triglycerides도 3주간 노화처리로 5.68-9.4%, 변색균처리로 38.5-40.0% 높은 감소율을 나타냈다. resin acids의 경우 3주간 노화처리로 6.1-11.3%, 변색균처리로 36-41.5%의 감소율을 나타냈다. 변색목재의 펄프화와 관련하여 소나무재 및 리기다소나무재의 크라프트펄프화결과, 알칼리펄프화에 비하여 펄프수율이 2-3% 높아졌다. 최적펄프화조건으로 활성알칼리농도 20%에서 펄프수율이 46.9-47.8%, reject율이 3.21-3.52%로 낮았다. 변색균처리한 목재도 활성알칼리 20%에서 펄프수율이 비교적 높은 43.5-45%를, reject율이 1.3-1.45%로서 변색균처리 모두에서 현저히 낮아짐을 알 수 있었다.

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Non-chlorine Bleaching of Oak Kraft Pulp by Ozone (오존을 이용한 신갈나무 크라프트펄프의 무염소표백)

  • 김동호;백기현
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.2
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    • pp.36-45
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    • 1997
  • Newly bleaching sequence using oxygen, ozone and hydrogen peroxide has introduced to avoid pollution hazards from chlorinated organic compounds, because chlorine dioxide substitution bleaching was produced a little chlorinated organic substance. Oxygen-type chemicals replaced for chlorine has attracted much research attention. Bleachability of ozone was improved at low temperature and high pulp consistency. In third bleaching followed OZ bleaching, addition of O2 and NaBH4 in alkali extraction was effective than only alkali extraction. Bleachability of pulps in ozone bleaching(Z) was improved at higher consistency and lower temperature The addition O2 and NaBH4 in alkali extraction after OZ bleaching sequence improved brightness, when compared to those obtained by only alkaline extraction. Pulps bleached by ECF bleaching sequences such as OZEoD and OZEopD was obtained by 90% ISO brightness. The brightness of pulp bleached by TCF sequences with the ozone dosage of 1.6% was approached to target brightness (88~90%ISO). Pulps bleached Z stage combined bleaching sequence was reduced the viscosity to a little greater extent. However, physical properties of pulps was not great different compared to those bleached by conventional bleaching sequences. A pollution index of bleaching effluente by ozone combined bleaching sequences was lower than by conventional bleaching sequence, but somewhat higher than multistage bleaching sequences combined C/D stage.

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