• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.60-71
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• 1992

To investigate the delignification behaviour in solvolysis pulping process, Populus alba ${\times}$ glandulosa H. and Pinus Kuraiensis S. et Z. were cooked with p-cresol and vater solvent(2:8, 5:5, 8:2 v/v) at $175^{\circ}C$ for 9 cooking time levels(20, 40, 60, 80, 100, 120, 140, 160, 180, min). Pulp yield, residual lignin content, de lignification rate, decarborhydration rate were determined. Delignification behaviours were analyzed by TEM. 1. The p-cresol-water solvent cooking of P. alba ${\times}$ glandulosa showed good delignification at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v), while the cooking of P. koraiensis with the p-cresol and water mixture ratio of 5:5 was no good. 2. P. alba ${\times}$ glandulosa showed three step-delignification phenomena at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v) anti 5:5(v/v). But P. koraiensis showed a first order delignification reaction at the same mixture ratio of p-cresol and water solvent system. 3. In TEM micrograph obtained for the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), the partial delignification of the cell corner of P. alba ${\times}$ glandulosa and P. koraiensis were observed at 60min. of cooking time. Complete delignification at the cell corner of P. alba ${\times}$ glandulosa was observed at 160min. and that of P. koraiensis was observed of 180min. of cooking time. 4. In optical microscopic observation, fiber separation of P. alba ${\times}$ glandulosa occured at 120min. and that of P. koraiensis began at 140min. of cooking time. 5. At the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), middle layer on secondary wall($S_2$) and cell corner of P. alba ${\times}$ glandulosa were more selectively delignified than primary wall(P) and outer layer on secondary wall($S_1$). However P. koraiensis did not showed any difference in delignification between cell wall layers and cell corner.

• 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.

• 펄프종이기술
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• 제35권1호
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• pp.41-47
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• 2003

Recently, interest in utilization plan of recycling paper have been enhanced. Therefore, this research aimed to develop the manufacture process of cellulose acetate using old newsprint by acetosolv pulping process. And the manufactured cellulose acetate was also analyzed, especially based on chemical properties. The summarized results in this research were as follows; Reaction time, kind and amount of catalyst, and ratio of liquor to material were varied during acetosolv pulping process of old newsprint. Ratio of liquor to material did not give the significant difference in reaction product. Delignification rate was increased with increasing reaction time during acetosolv pulping, but yield and degree of substitution decreased with increasing reaction time. Sulfuric acid are better catalyst than hydrochloric acid in acetosolv pulping process for old newsprint, and optimal addition amount of catalyst was 1% based on reaction material. Delignification, yield, and degree of substitution were influenced by the catalyst and reaction time. Under pulping condition of $120^{\circ}C$ in 1/12 liquor to material ratio and 60min, degree of substitution was about 0.7. The acetylation reaction was not completely caused by these reaction condition. The examination of the FT-IR spectra revealed that absorption band(1200$\textrm{cm}^{-2}$, 1,750$\textrm{cm}^{-1}$) caused by carbonyl group were confirmed.

• Journal of the Korean Wood Science and Technology
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• 제49권4호
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• pp.287-298
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• 2021

Torch ginger (Etlingera elatior Jack) is a potential source of lignocellulose material for various derivative products. This study aims to determine the chemical components, ratio of syringyl to guaiacyl units (S/G) in lignin, and crystallinity of the biomass of torch ginger. The effects of soda pulping on the chemical characteristics of torch ginger pulp were also studied. Pulping of the chips was conducted with active alkali of 15%, 20%, and 25% and a Liquor-to-Wood (L/W) ratio of 4:1, 5:1, and 6:1. The impregnation and pulping times at maximum temperature (170℃) were 120 and 90 min, respectively. To assess the effect of treatments on the properties of pulping, a two-factorial experimental design was applied. Results showed that the content of α-cellulose and hemicellulose in the torch ginger was 48.48% and 31.50%, respectively, with an S/G ratio of 0.70 in lignin. Soda pulping changed the crystalline structure of the biomass from triclinic to monoclinic. Active alkali, L/W ratio, and interactions considerably influenced the observed responses. The degree of delignification increased with an increase in the loading of active alkali, which lead to a decrease in the kappa number of the pulp. An active alkali content of 25% and an L/W ratio of 6:1 resulted in the highest delignification selectivity with a kappa number of 2.78 and a yield of 24%. Given its cellulose content and ease of pulping, torch ginger can be a potential raw material for derivative products that require delignification as pretreatment. However, the increase in cellulose crystallinity should be considered when converting torch ginger to bioethanol.

• Journal of the Korean Wood Science and Technology
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• 제22권2호
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• pp.30-36
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• 1994

Steam explosion process is one of the most efficient, pretreatment method for the utilization of lignocellulosic biomass. The carbxymethyl-cellulose(CMC) was prepared with steam exploded wood(EXW), pine(Pinus densiflora) and oak(Quercus mongolica), by standard method using isopropyl alcohol and monochloroacetic acid. The range of water solubility of carboxymethylated pine exploded wood was 45.2~66.8 % and those of oak was 60.7~84.7 %. The degree of substitution(D.S) of carboxymethylated pine exploded wood was 0.11~0.33 and oak exploded wood was 0.48~0.76. The color of carboxymethylated pine and oak exploded wood was brown-black. When carboxymethylated EXW was purified by sulfuric acid, the yield of carboxymethylated wood was lower than non-treated one. However, the color was still brown-black although after delignification. In carboxymethylated EXM prepared after delignification, the water solubility and degree of substitution(D.S) of pine were 81.4~95.9 % and 0.71~0.79, and those of oak were 76.2~89.5 % and 0.79~1.05. The values were higher than non-treated. The degree of substitution of purified carboxymethylated wood prepared with delignified EXM, pine and oak were 0.50~0.71 and 0.70~0.88. The color of carboxymethylated wood was white. In carboxymethylated wood preparde after delignification of EXM, swelling ratio and water retention value of pine were 95.9~96.5 and 580.0~751.2, those of oak were 76.2~89.5 and 124.3~307.6.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.30-36
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• 1993

Wood chips of oak (Quercus mongolica) and larch (Larix leptolepis) were treated with a relatively low pressure steam(10~20 kg/$cm^2$) for 10~20 min (first-stage),and then increased pressure up to 30kg/$cm^2$ for 30 second (second-stage), and steam pressure was released intentionally to air. Main components of exploded wood were separated with 1% NaOH and hot water-methanol. In this work, the more effective low pressure explosion condition and separation method of wood main component were investigated. The results can be summarized as follows; 1. The yields of exploded wood were generally decreased with increasing steam pressure and reaction time. 2. The proper condition of steam explosion in low pressure for the separation of wood main components was 15kg/$cm^2$-10 min, in oak wood and 20kg/$cm^2$-10 min., then 30kg/$cm^2$-0.5 min, in larch wood. 3. The 23% of elude hemicellulose was obtained from the exploded oak wood which was treated with optimal condition. 4. In the case of hot water-methanol extraction, the ratio of delignification was 14~23% in the exploded larch wood and 42~55% in the exploded oak wood. 5. The methanol was more effective than 1% sodium hydroxide solution for extraction of lignin from exploded wood.

• 펄프종이기술
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• 제48권2호
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• pp.28-33
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• 2016

This study was conducted to investigate the effects of deep eutectic solvent (DES) treatment on properties of TMP fibers and handsheets. DES was prepared by mixing of lactic acid and betaine (L and B), and the molar ratio of these two components mixtures was controlled to 2:1 (L:B=2:1) and 5:1 (L:B=5:1). As results, lignin was partly extracted from the TMP fibers. Especially, the delignification of TMP samples was promoted according to the increase of the molar ratio of lactic acid. Except for tear index, both tensile index and burst index of handsheets were increased when higher molar ratio of lactic acid was mixed for DES preparation. However, the LB DES treatment of TMP fibers didn't give any effect on the optical properties of TMP handsheets. The plausibility of TMP fiber was to be enhanced by LB DES treatment.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.53-60
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• 1993

Substrates used were hardwood-Suwon poplar-(Populus alba${\times}$glandulosa L.) and softwood-pitch pine-(Pinus rigida M.). And these substrates were steam exploded then treated with sodium chlorite at 75$^{\circ}C$ with occasional stirring in order to obtain samples which had different lignin contents and crystallinity. And then this resulting samples incubated with a commercial cellulase derived from Trichoderma ressei. The contents of Klason lignin were decreased as the increasing of the ratio of sodium chlorite in the two species. The effect of hardwood was more effective than that of softwood in the same ratio of sodium chlorite. The minimum contents of Klason lignin were 0.8% and 5.1% respectively. And the crystallinities of cellulose were increased very little as increasing of the ratio of sodium clorite. The hydrolysis extent of the two species were increased as the increasing of delignification. Especially, the hydrolysis extent of hardwood was more higher than that of softwood. The maximum hydrolysis extent were 89.8% and 71.1%, respectively.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.56-62
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• 2005

The catalytic effect of molybdovandophosphate heteropolyanion (HPAs) on the delignification of kraft bagasse pulp by hydrogen peroxide has been investigated. Very small amounts of the catalyst (0.05 0.3 mM/l) gave convenient results. Partial reduction of the catalyst was also studied. The effect of reaction medium (water, ethyl alcohol and acetone) on the bleaching was also studied. The results obtained show that the optimum condition for bleaching in presence of polyoxometalate were 0.05 mM/l catalyst concentration at $70^{\circ}C$ reaction temperature and $7\%$ consistency at pH 2 in aqueous medium. The ratio of water to solvent of 60:40 from acetone gives higher brightness than ethyl alcohol. The catalyst solution can be reused for 5 times without any reduction in brightness. ESR for the blank and exhausted solutions under different conditions was also carried out to find the relation between reduced metals and pulp brightness.

• Journal of the Korean Wood Science and Technology
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• 제28권3호
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• pp.34-41
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• 2000

최근 들어 범용 플라스틱계 고분자의 환경오염이 심각한 사회적 문제를 유발함에 따라 많은 연구자들이 생분해성 고분자 소재 개발에 관한 연구를 시행하고 있으며, 본 연구에서는 폐지를 이용한 생분해성 고분자물질의 제조를 위하여 폐지의 화학적 성상 및 최적 전처리조건을 검토하기 위해 시행하였고, 그 결과는 다음과 같다. 각 공시재료별 화학적 조성분 분석 결과 신문폐지와 골판폐지의 리그닌 함량이 사무실 폐지에 비해 높게 나타났다. 또한 건식해리 펄프에 비해 습식해리 펄프의 회분 함량이 낮게 나타났다. 생분해성 고분자의 제조를 위해서는 반드시 폐지의 화학적 전처리가 요구되며, 습식해리 시료가 건식해리 시료에 비해 전처리 효과가 우수하였다. 본 연구에서 행해진 화학적 전처리 중 아염소산나트륨으로 가온($70^{\circ}C$)처리한 전처리방법이 가장 우수한 것으로 판명되었다. 한편 산소-알카리 전처리는 탈리그닌처리 효과는 우수하였지만, 수율이 과도하게 저하되고, 탄수화물의 붕괴에 따른 셀룰로오스의 중합도 저하로 인해 전처리 공정으로서 부적합하다고 판단되었다.