• Journal of the Korean Wood Science and Technology
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• 제31권3호
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• pp.11-16
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• 2003

On nitrobenzene oxidation of aspen, spruce, and knauf wood meals gave rise to vanilline, syrigaldehyde, p-hydroxybenzoaldehyde, vanillic acid, and other minor oxidation products. The phenolic aldehydes (p-hydroxybenzaldehyde, vanilline, and syringaldehyde) are derived from oxidative degradation of the corresponding 4-hydroxyphenylpropane units and their ethers. The lignin content of knauf wood meals was different as the concentration of NaOH solution and cooking temperature. The lignin contents of aspen, spruce, and knauf wood meals were decreased as laccase treatment. The laccase caused C-oxidation, demethylation, cleavage in phenolic groups and C-C cleavage in syrigyl structures.

• Journal of the Korean Wood Science and Technology
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• 제23권1호
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• pp.54-60
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• 1995

This paper reports on the changes of equilibrium moisture contents and specific surface areas of Poplar wood(Populus euramericana) for various steam explosion treatments. Equilibrium moisture contents(EMC) and specific surfaces of steam exploded woods were measured under the moisture adsorption course at 25$^{\circ}C$, and compared with those of other materials and wood meals. The EMCs of steam exploded wood meal were 1~5% less in comparison with that of wood meal. In the case of delignified steam exploded wood meal and delignified wood meal, the same tendency was appeared too. But absolute values of EMCs for delignified wood meals were larger than those of the wood meal. For the changes of EMC by the steam exploded conditions, the EMC decreased with the increase of the steam explosion pressure. On the other hand, specific surface areas were calculated from BET plots based on amounts of monomolecular vapor adsorption of various wood meals. Specific surface areas of the wood meal and delignified wood meal were 90~145, 34~90($m^2/g$) respectively, and which were greater in comparison with those of steam exploded wood meals and delignified steam exploded wood meals. From these results, it is considered that the amount of water vapor adsorption was decreased by the increase of the crystallinity, effect of heat treatment, and coating by melted lignin in during the steam explosion.

• 펄프종이기술
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• 제42권3호
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• pp.67-73
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• 2010

Pine (Pinus densiflora) and aspen (Populus euramericana) wood meals were treated with ozone at various time schedule in acidic condition. The lignin contents and surface area of the ozone treated wood meals were determined and the enzymatic hydrolysis rate of ozonated wood meals was evaluated. The feasibility of enzymatic hydrolysis of the ozone treated wood meal was obviously influenced with the degree of delignification. After ozone treatment of wood meal for 10min, total pore volume were slightly increased in the surface of wood meal. When wood meals were treated with ozone longer than 10min, few change in the pore volume was observed. However, the area of over $50{\AA}$ of pore size is increased with ozonation time. As a conclusion, the rate of enzymatic hydrolysis of wood is more effective with the pore size distribution than the total pore volume.

• 펄프종이기술
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• 제43권1호
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• pp.23-28
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• 2011

The pine wood meal was ozonated in acidic water. A 91.3% of lignin and 13% of polysaccharides in pine wood meal were degraded with 180 min ozonation. The phenolic hydroxyl groups of lignin in ozonated wood meals were increased with ozonation time. The vanillin content in nitrobenzene oxidation products of lignin is decreased with 10 min. ozonation and it was slightly increased with ozonation time. The sugar composition of ozonated wood meals showed that the hemicellulose was more susceptible to ozonation than cellulose. The crystallinity of ozonated wood meal was increased.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2005년도 춘계학술발표논문집
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• pp.188-190
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• 2005

• 임산에너지
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• 제24권1호
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• pp.39-46
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• 2005

본 연구에서는 연속형 초임계수 분해장치를 이용하여 처리온도 별로 현사시목재의 당화 가능성과 현사시목재 각 성분의 분해특성을 분석하였다. 미세하게 분쇄한 현사시목분을 물의 초임계압력(23MPa) 조건하에서 각각 아임계온도$(275^{\circ}C,\;325^{\circ}C)$와 초임계온도$(375^{\circ}C,\;415^{\circ}C)$에서 각각 2분간 처리하였다. 갈색을 띤 현사시목분의 액상분해산물에는 어느 정도의 미분해 고형분이 포함되어 있었다. 초임계수 분해온도가 높을수록 현사시목분의 분해율은 증가하여 초임계조건인 $375^{\circ}C$에서는 현사시목분의 $94\%$까지 분해되었다. 각 처리조건에서 생성된 환원당량을 DNS법으로 측정한 결과, 처리온도가 상승함에 따라 생성된 환원당량은 점차 감소하는 경향을 나타내었다. 이는 반응 초기에 생성된 환원당들이 높은 온도의 반응기를 통과하면서 열분해와 유사한 화학적 반응에 의해 더욱 분해되어 퓨란계 화합물로 전환된 것으로 예측되었다. 리그닌의 분해특성을 살펴보기 위하여 액상의 분해산물을 ethylacetate로 추출하여 유기용매 가용부를 GC-MS로 분석하였다. 리그닌의 분해산물은 대부분 페놀성 유도체인 vanillin, guaiacol, syringaldehyde, 4-prophenyl syringol과 dihydrosinapyl alcohol등으로 확인되었으며, 이들의 농도는 처리온도가 상승함에 따라 증가하는 것으로 나타났다. 이러한 리그닌 분해산물은 리그닌고분자의 주요 결합인 에테르 결합이 높은 온도조건하에서 분해에 의한 것으로 예측되었다.

• 펄프종이기술
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• 제43권1호
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• pp.29-35
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• 2011

Since the role of lignin in the wood cell wall is to keep integrity and structure rigidity of lignocellulosic substrate, lignin of the cell wall has to be destroyed before enzymatic hydrolysis of wood polysaccharides. The aspen wood meals were delignified with ozone in acidic condition. The chemical characteristics of wood meal were investigated. The 60% of lignin and almost zero % of polysaccharides in aspen wood meal was degraded with 10min. ozone treatment. The phenolic hydroxyl groups of lignin in ozonated wood meal were increased with ozonation time. The sugar composition of ozonated wood meal showed that the hemicellulose was more susceptible to ozonation than cellulose. The yield of aldehyde was increased in some degree with 10min. ozone treatment and decreased with longer ozone treatment.

• 펄프종이기술
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• 제48권1호
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• pp.119-126
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• 2016

In this study, we separated the lignin from the wood by using the high boiling point solvent for developing more environmental friendly pulping method. High boiling point solvents as Ethers, glycols and ketones were used to remove the lignin in the pine wood meals. The Yield and lignin content of residual wood meals was reduced according to the input of the catalyst. Me-C, E-Ca, TEG and MIBK had the best delignification rate of 9 kinds of high-boiling point solvents. At the hydrolysis ratio of the selected solvents, The TEG was highest remain ratio of carbohydrates and the E-Ca was lowest remain ratio of lignin. And the Me-C was most excellent lignin hydrolysis ratio at the low catalyst. The selectivity of delignification of Me-C, E-Ca, TEG and MIBK solvents were 49.6, 49.9, 53.8 and 53.1%, respectively, and its values were similar to those of the commercial Kraft Pulp.

• Journal of the Korean Wood Science and Technology
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• 제17권3호
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• pp.1-7
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• 1989

This study was performed to obtain the optimal condition that hydrolyzed exploded pine(Pinus densiflora), oak(Quercus serrata) and birch wood(Betula platyphylla var. japonica) by using sulfuric acid. The results obtained were summarized as follows: In hydrolysis of wood meal with sulfuric acid. maximum yield of sugar appeared that pine was 12 hours. oak and birch were 24 hours with 65% sulfuric acid. Futhermore, when wood meal and exploded woods were hydrolyzed with 65% sulfuric acid at $23^{\circ}C$ for 6 hours(primary hydrolysis), diluted to 3% and hydrolyzed again at $100^{\circ}C$ for 2 hours(secondary hydrolysis), the maximum sugar yield of wood meals were 6 hours. those of higher steam exploded pine wood was 3 hours. of lower steam exploded oak and birch woods were 6 hours. The sugar analyses of exploded wood showed that the amount of arabinose and xylose residue rapidly decreased. content of nemicelluose decreased with increase of steaming time and pressure.

• Journal of the Korean Wood Science and Technology
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• 제12권4호
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• pp.19-30
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• 1984

This experiment was carried out to investigate the effects of autohydrolysis and extraction conditions on the separation of the chemical substances, the extractability of lignin by dioxane, and the yield of reducing sugars from cellulosic substrates by using a commercial cellulase derived from Trichoderma viride. Air-dried wood meals through 0.42mm (40 mesh) screen and retained on 0.25 mm (60 mesh) of Populus alba-glandulosa and Pinus koraiensis were autohydrolyzed with water at $180^{\circ}C$ for 30 and/or 60 minutes in a 6 liter stainless-steel digester with or without 2% 2-naphthol. The hydrothermally-treated wood meals were extracted the lignin with 100%, 90%, 75% and 50% dioxane solutions at $70^{\circ}C$ for 4 hours, respectively. The results obtained were as follows; 1) After autohydrolysis of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. In case of Pinus koraiensis, the yield was not affected by 2%, 2-naphthol addition at the autohydrolysis in the digester. 2) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Extraction of 50% dioxane solution was the best solvent for the yield among the solutions of 100%, 90%. 75% and 50% dioxane. In case of Pinus koraiensis, the yield was not affected by 2% 2-naphthol addition and the solution of 90% dioxane was the poorest solvent for the yield. 3) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the Klason lignin content in cellulosic substrates for enzymatic hydrolysis decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Klason lignin content was the lowest after extraction by 90% or 75% dioxane solution. The content was also affected by interaction of the three factors-autohydrolysis time, 2% 2-naphthol addition and concentration of dioxane. In case of Pinus koraiensis, the Klason lignin content increased with 2% 2-naphthol addition but was not affected by the concentration of dioxane solution. 4) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the extractable Klason lignin content by extraction increased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. The extractable lignin content was the highest after extraction by 90% or 75% dioxane solution. In case of Pinus koraiensis, the extractable lignin content increased with 2% 2-naphthol addition. Extractions by 100%, 90% and 50% dioxane solutions were more effective for the extraction of Klason lignin than by 75% dioxane solution. 5) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of reducing sugars increased with lengthening the autohydrolysis time from 30 minutes to 60 minutes but was not affected by 2% 2-naphthol addition and the concentration of dioxane. The yield of reducing sugars after enzymatic hydrolysis was slightly higher by extractions with 90%, 75% and 50% dioxane solutions than with 100% dioxane. In case of Pinus koraiensis, the yield of reducing sugars was not affected by 2% 2-naphthol addition but affected by the concentration of dioxane. The yield of reducing sugars was the highest in cellulosic substrates extracted by 100% dioxane solution.