• Title/Summary/Keyword: Kraft Lignin

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Effect of Tree Age and Active Alkali on Kraft Pulping of White Jabon

  • Wistara, Nyoman J.;Carolina, Anne;Pulungan, Widya S.;Emil, Nadrah;Lee, Seung-Hwan;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.5
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    • pp.566-577
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    • 2015
  • White Jabon (Anthocephalus cadamba Miq.) is one of the fast growing species in Indonesia and has the potential as the raw material for pulp and paper. In this research, 3, 5, and 7 years old White Jabon woods were pulped under different active alkali charge of 15%, 18%, 21%, 24%, and 27%, and its effect on delignification degree, kappa number, pulp yield, pulp viscosity, brightness, unbeaten freeness, and delignification selectivity was investigated. The results showed that tree age and active alkali concentration influenced the quality of pulp and pulping properties, except for that of unbeaten freeness. Delignification degree increased with increasing active alkali charge, and this brought about the decrease of pulp kappa number. The pulping yield tended to decrease below the Klason lignin of approximately 4%. Even though the 3 years old wood resulted in the highest brightness and highest delignification selectivity, the highest pulp viscosity was obtained with the 5 years old wood. The dominant fiber length of all wood ages was in the range of 1.2 - 2.0 mm. The 3 years old wood was considered to be the most promising raw material for kraft pulping in the view point of pulping properties, pulp quality and harvesting rotation.

Specific Surface Area Characteristic Analysis of Porous Carbon Prepared from Lignin-Polyacrylonitrile Copolymer by Activation Conditions (리그닌-PAN 공중합체로 제조한 다공성 탄소 소재의 활성화 처리 조건에 따른 비표면적 특성 연구)

  • LEE, Hyunsu;KIM, Seokju;PARK, Mi-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.4
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    • pp.299-314
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    • 2021
  • In this study, we investigated the effect of temperature on specific surface area and electrochemical properties when lignin-based porous carbon (LBPC) with potassium hydroxide (KOH) is activated. After preparing LBPCs using lignin-polyacrylonitrile (PAN) copolymer, which was synthesized by graft polymerizing lignin and acrylonitrile as a precursor, activated LBPCs (KA-LBPC-6, 7, 8, 9) were manufactured by activating LBPC with KOH at 600℃, 700℃, 800℃ and 900℃. To identify the surface characteristics of KA-LBPC, observations were made with a scanning electron microscopy (SEM), and the pore characteristics were identified via specific surface area analysis. The electrochemical properties were analyzed using a three-electrode system. The experiment has shown that micropores formed by activation can be observed in SEM images. KA-LBPC-7 had the best pore characteristics among KA-LBPCs, with a specific surface area of 2480.1 m2/g, a micropore volume of 0.64 cm3/g, and a mesopore volume of 0.76 cm3/g. KA-LBPC-7 showed the best electrochemical properties with a specific capacitance of 151.3 F/g at the scan rate of 2 mV/s.

Molecular Characterization of an Apple cDNA Encoding Cinnamyl Alcohol Dehydrogenase

  • Kim, Sung-Hyun;Lee, Jae-Rin;Shin, Yong-Uk;An, Gyn-Heung;Kim, Seong-Ryong
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.475-481
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    • 1999
  • The study of lignin, a major component of secondary cell wall, has been partly focused on its removal from the woody part in the kraft pulping industry. Cinnamyl alcohol dehydrogenase (CAD; EC 1.1.l95) catalyzes the synthesis of cinnamyl alcohols from corresponding cinnamaldehydes. A cDNA clone, MdCADl, encoding putative CAD from apples (Malus domestica Borkh. cv Fuji) was characterized in this study. The clone contains an open reading frame of 325 amino acid residues, which shows a greater than 80% identity with Eucalyptus CADl. MdCADl mRNA was detectable in vegetative tissues and was strongly expressed in the fruit. The expression pattern of MdCADl mRNA in the fruit peel after light exposure was also examined. The mRNA was rapidly increased until 1 day after light exposure and remained stable thereafter, suggesting that MdCADl is light inducible. The inducibility of the MdCADl gene was examined using several environmental stresses. Mechanical wounding of leaves increased the MdCADl mRNA level and the induction was further increased by salicylic acid. Southern blot hybridization showed that there is either one or a few copies of CAD genes in apples. To our knowledge, it is believed that MdCADl is the first CAD clone expressed predominantly in fruit.

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Complete genome sequence of Bacillus aryabhattai K13 isolated from compost (퇴비에서 분리한 Bacillus aryabhattai K13의 유전체 염기서열)

  • Patil, Kishor Sureshbhai;Lee, Seung-Je;Le, Ve Van;Jeon, So Hyun;Chae, Jong-Chan
    • Korean Journal of Microbiology
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    • v.53 no.4
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    • pp.332-333
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    • 2017
  • Bacillus aryabhattai K13 was originated from enriched culture of compost using 1% kraft lignin as a sole carbon and energy source. The complete genome of strain K13 consists of one 5.0 Mb chromosome and two circular plasmids with 139 kb and 78 kb, respectively. Analysis of the genome determined in this study may contribute to identify the genes responsible for degradation of lignin.

On Possible Application of Microorganism for Chemical Pulping (화학(化學)펄프 제조(製造)에 미생물(微生物)의 응용(應用) 가능성(可能性))

  • Lee, Seon-Ho;Yoon, Byong-Ho;Lee, Won-Yong
    • Journal of Forest and Environmental Science
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    • v.13 no.1
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    • pp.143-152
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    • 1997
  • The decayed wood by Fomes pini (Thore) Lloyd required a smaller H factor than the sound wood for pulping to permanganate number 20. The H factors for the decayed wood pulping by the kraft and soda processes were reduced by 15% and 17%, respectively, in the presence of 1% anthraquinone. The wood components degraded by fungi are normally more readily solubilized in alkali than the corresponding components in sound wood. The nonphenolic ${\beta}$-O-4 type lignin model compound, veratrylglycerol-${\beta}$-guaiacyl ether(I), and phenolic model compound, syringylglycerol-${\beta}$-syringyl ether(III), were degraded by the white-rot fungi to yield ${\alpha}$-guaiacoxy-${\beta}$-hydroxypropioveratrone(II) from the former and ${\alpha}$-syringyloxy-${\beta}$-hydroxypropiosyringone(IV) from the latter. Structures of the degradation products indicated that C ${\alpha}$-oxidation could occur with white-rot fungi. It has been shown that the alkaline cleavage of ${\beta}$-aryl ether bonds in the lignin units is accelerated by the presence of ${\alpha}$-carbonyl groups.

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Influence of Conductivity and Anionic Trashes on Adsorption Behavior of Cationic Starches (전기전도도와 음이온성 트래쉬에 따른 양상전분의 흡착 거동변화)

  • 허동명;이학래
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.3
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    • pp.10-18
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    • 1999
  • The influence of simple electrolyte or anionic trashes on cationic starch adsorption was examined using deinked pulp and bleached thermomechniical pulp. Adsorbed amounts of cationic starches increased slightly , then decreased abruptly as the concentration of simple electrolyte increased. This phenomenon was discussed based on the compression of electrical double layer and conformation change of starch molecules. Also, the effect of the type of simple electrolytes on starch adsorption was examined and discussed. Addition of sodium slilicate increased starch adsorption since it increased surface charge density of fibers. On the other hand, addition of kraft lignin decreased cationic demand of the pulp slurries and adsorbed amounts of cationic starches. Nonionic surfactant did not show any significant effect on the cationic demand of pulp slurries. When simple electrolytes were added to the stock , grater adsorption or cationic starches was obtained with starches of lower degree of substitution . On t도 other hand, amount of adsorbed starches decreased for lower DS starches when the concentration of anionic trashes increased.

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New Bleaching Method for KP with Permanganate(III) -Evaluation of Role of Oxalic Acid as a Acid Catalyst and a Reductant on the Permanganate Oxidation with Phenolic Model Compounds- (과망간산칼륨을 이용한 KP의 새로운 표백법(제3보) -모델화합물 실험에서 Oxalic acid 첨가의 평가-)

  • Yasuo Kojima
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.73-79
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    • 2001
  • Stricter environmental demands have increased the need to replace conventional C/D bleaching sequence by chlorine-free sequence. Permanganate is well known as a powerful oxidant and have been used industrially in variable fields. However, it has considered to be difficult to use permanganate as a bleaching reagent because of its strong oxidative effect decreasing the viscosity of pulps extremely. We have tried to use permanganate as a bleaching reagent for KP under the mild condition and it was clear that pernanganate oxidized lignin remained in pulps selectively and increased pulp brightness decreasing K number of pulps with small degradation of cellulose. We have employed the neutral condition in the permanganate bleaching process in this study. In this case, permanganate was converted to manganese dioxide after bleaching reaction. The manganese dioxide is remained in the treated pulp fibers because of its insolublity in water. So it was required to reduction the manganese oxide to manganese ion by using reductants with acid. In this paper, we proposed to use oxalic acid as a reducing reagent converting manganese oxide to manganese ion after bleaching reaction. Oxalic acid plays the role as a reductant and a acid, so post-treatment after bleaching became to be easy by using oxalic acid. On the study using lignin model compounds, it was clear that permaganate react with phenols firstly, after that oxalic acid reduce the manganese oxide to manganese ion in the mixture of permanganate, phenols and oxalic acid. Several lignin model compounds ($\textit{p}$-hydroxybenzaldehyde, vanillin, syringaldehyde, veratraldehyde) are selected to elucidate the effect of substituents on reaction rate and its mechanism with permanganate including oxalic acid in this study. Except for veratraldehyde, the rate of oxidative degradation of phenolic compounds by permanganate with oxalic acid are higher than neutral condition. Especially, the degradation rate of $\textit{p}$-hydroxybenzaldehyde are strongly dependent on pH of reaction mixture. On the other hand, the degradation rate of veratraldehyde are decreased with decreasing pH and main degradation product is veratric acid. This result indicate that pH of bleaching liquor should be kept over 2 to degrade of non-phenolic lignin in the pulps effectively in permanganate bleaching.

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Effect of active alkali concentration on the delignification of Larch UKP (활성(活性) 알칼리 농도(濃度)가 일본잎갈나무 UKP의 탈(脫)리그닌에 미치는 영향(影響))

  • Won, Jong-Myoung;Jo, Byoung-Muk
    • Journal of the Korean Wood Science and Technology
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    • v.4 no.1
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    • pp.21-27
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    • 1976
  • This study was carried out in order to obtain the effect of active alkali concentration. Sulfidity 25%, maximum temperature 170$^{\circ}C$, cooking time 3hrs., liquor to wood ratio 5 : 1 in the kraft cooking conditions were maintained. Active alkali concentration were varied at intervals of 3% between 12% and 24%. The rates of de lignification increased with an increase in active alkali concentration and beatability, brightness, and strength of pulp also improved. The total pulp yield trand to decrease with an increase of active alkali concentration. The maximum screened pulp yield were obtained between 18% and 21% A.A.. Therefore, the optimum active alkali concentration was 18~21%.

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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.

Quality of Mountain Pine Beetle Infested Fibers: Implications on the Production of Pulp and Paper Products

  • Kim, Yong-Sik;Obermajer, Alice;Korehei, Reza;Kadla, John F.;Yoon, Byung-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.1
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    • pp.1-8
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    • 2009
  • Mountain Pine Beetle (MPB) attacked pine was evaluated for pulp quality, chemical and physical properties, and bleachability. Chemical analyses showed that the dehydroabietic acid and total acetone extractives content were higher in the year 3 (grey) attacked MPB chips and lower in the year 5 (grey) attacked MPB chips as compared to a typical SPF (spruce/pine/fir) reference. Lignin and carbohydrate content of the MPB wood chips were comparable to the SPF. Similarly, there was little difference in kappa number, pulp yield and liquor consumption between the 3 and 5 year MPB attacked wood. Likewise there was no significant difference in the resulting tear strength, burst, or tensile strength. There appeared to be an improved bleaching response in the MPB attacked pulp as compared to the SPF reference, but this was accompanied by a slightly lower bleached pulp yield and higher bleach filtrate COD and solids content.