• Journal of the Korean Wood Science and Technology
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• 제10권4호
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• pp.67-75
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• 1982

모텔리그닌의 펄프화(化) 처리(處理) 및 폐액(廢液)리그닌의 반응생성물(反應生成物)로부터 알칼리 및 설페이트 펄프화중(化中)에 일어나는 반응양식(反應樣式)을 조사(調査)한 것이다. 알칼리의 처리결과(處理結果)는 친핵시약(親核試藥)에 의해 페놀레이트 이온이 생성(生成), 퀴논메타이드 중간체(中間體)를 걸쳐 $C_6-C_3$ 단위(單位)의 ${\alpha}$위(位) aryl은 탈리(脫離)하여, 리그닌은 저분자화(低分子化)가 시작되고, 저분자생성물(低分子生成物)은 축합반응(縮合反應)에 의해 극(極)히 일부(一部)는 고분자화(高分子化)된다. 저분자화(低分子化)된 리그닌은 산화(酸化)에 의해 퀴노이드 착색구조(着色構造)를 형성(形成)한다. 페놀성의 일부(一部) 및 비(非)페놀성리그닌은 oxirane와 thiirane의 중간체(中間體)를 거쳐 $C_6-C_3$ 단위(單位)의 ${\beta}$위(位)의 arylether가 탈리(脫離)된다. 그러나, hydrosulfide 이온은 hydroxide 이용 보다 강(强한)한 친핵종(親核種)이므로 thiirane의 중간체(中間體) 생성(生成)이 용량(容量)하여 개열(開裂)이 더욱 촉진(促進)된다. 저분자(低分子)리그닌의 고분자축합(高分子縮合)은 벤젠핵(核)의 2.6 위(位)보다 5위(位)에 축합(縮合)이 많이 일어 난다.

• 펄프종이기술
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• 제47권1호
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• pp.35-44
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• 2015

Thermomechanical pulping process uses large amounts of energy, mostly electricity to run electrical facilities. Thermomechanical pulp (TMP) made from Pinus densiflora also has a big drawback that refining consumes 90 per cent of the total energy used in TMP process. This study explored to draw up a way to save refining energy through different thermal treatment at the stages of presteaming and refining. Presteaming temperature was $80^{\circ}C$, $100^{\circ}C$, and $120^{\circ}C$. After presteaming at each temperature, refining was carried out at $100^{\circ}C$, $120^{\circ}C$, and $140^{\circ}C$ respectively. In a presteaming stage, steaming temperature over $120^{\circ}C$ greatly contributed to the decrease of refining energy leading to earlier attainment of a target freeness, irrespective of refining temperature. In addition, NaOH treatment with presteaming enhanced better development of fiber properties during refining than presteaming without NaOH. High temperature refining at $140^{\circ}C$ produced a high strength paper, and wood chips treated by alkali responded better to refining than at over $120^{\circ}C$. Improved softening effect on wood chips led to the decrease in shives contents but it gave no effect on pitch contents of TMP.

• Journal of the Korean Wood Science and Technology
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• 제44권4호
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• pp.477-493
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• 2016

A single process using hot water (0% green liquor) and green liquor (GL) was investigated for pre-pulping extraction on two types of raw material. The GL was applied at different alkali charges of 0-5% on a dry wood weight basis. The extractions were performed at an H-factor 900 at $180^{\circ}C$. The 0% and 3% GL extraction detected acetic acid (AA) at 10.02 and $9.94g/{\ell}$, extracts derived from hardwood, 2.46 and $3.76g/{\ell}$, extracts derived from softwood, respectively. The single liquid-liquid extraction (LLE) was studied using tri-n-alkylphosphine oxide (TAPO). Response surface methodology (RSM) was employed as an efficient approach for predictive model building and optimization of AA recovery conditions. The extraction of AA was evaluated with a three-level factorial design. Three independent variables, pH (0.5-3.5), temperature ($25-65^{\circ}C$), and residence time (24-48 min) were investigated. Applying the RSM models obtained, the optimal conditions selected of extracts derived from hard- and softwood with a 3% GL were approximately pH 1.4, $26.6^{\circ}C$, 43.8 min and approximately pH 0.7, $25.2^{\circ}C$, 24.6 min, respectively. The predicted and experimental values of AA recovery yield were similar whilst sugar retention was 100%.