• Elastomers and Composites
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• 제46권3호
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• pp.195-203
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• 2011

친환경 소재인 바이오복합재료(bio-composites)의 제조를 위하여 기질 고분자로는 poly(lactic acid) (PLA)를 그리고 충전제(filler)로는 케나프 섬유(kenaf fiber)를 사용하였다. 또한 섬유와 고분자 사이의 계면결합 향상을 위해 아세틸화 케나프 섬유(acetylated kenaf fiber)와 상용화제(compatibilizer)를 첨가해 주었다. 본 연구에서는 화학처리와 상용화제가 기계적-점탄성과 형태학적 특성에 미치는 영향을 평가하였고, 섬유가 소수성이 될수록 기질 고분자와 높은 계면결합을 가지며 물성과 형태학적 성질 또한 향상된다는 결과를 보여줬다. 그러나 점탄성과 유리전이온도에는 큰 영향을 미치지 않는다는 사실을 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.209-210
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• 2019

Current international concerns are the energy crisis due to climate change and depletion of fossil fuels due to global warming. Korea has a very high dependency on energy imports 93%. In Korea, 63% of the country is forested, and a power plant using wood biomass is being built in Korea. Biomass fly ash, a by-product of biomass energy generation, is now being discarded. There is little research to utilize discarded biomass fly ash. Therefore, this study aims to solve the environmental problems, develop new mixed materials, improve the quality and utilize the biomass fly ash, which is a by-product of the industrial waste. As a result of the experiment, the flowability decreased as the replacement ratio of biomass fly ash increased. As the replacement ratio of biomass fly ash decreased, the amount of air content.

• 펄프종이기술
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• 제47권1호
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• pp.24-34
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• 2015

Domestic companies supplying electricity must increase obligatory duty to use renewable energy annually. If not met with obligatory allotment, the electricity-supply companies must pay RPS (Renewable Portfolio Standards) penalty. Although the power plants using a pulverizing coal firing boiler could co-fire up to around 3 per cent with wood pellets mixed in with coal feedstock without any major equipment revamps, they recorded only about 60 per cent fulfillment of RPS. Consequently, USD 46 million of RPS penalty was imposed on the six power supplying subsidiaries of GENCOs in 2014. One of the solutions to reduce the RPS penalty is that the power supply companies adopt the co-firing of torrefied lignocellulosic biomass in coal plants, which may contribute to the use of over 30 per cent of torrefied biomass mixed with bituminous coals. Extra binder was required to form pellets using torrefied biomass such as wood chips, PKS (Palm Kernel Shell) and EFB (Empty Fruit Bunch). Instead of corn starch, 30, 50 and 70 per cent of Larix saw dusts were respectively added to the torrefied feedstocks such as Pinus densiflora chips, PKS and EFB. The addition of saw dusts led to the decrease of the calorific values of the pellets but the forming ability of the pelletizer was exceedingly improved. Another advantage from the addition of saw dusts stemmed from the reduction of ash contents of the pellets. Finally, it was confirmed that torrefied oil palm biomass such as PKS and EFB could be valuable feedstocks in making pellets through improved binding ability.

• 자원리싸이클링
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• 제30권4호
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• pp.46-53
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• 2021

바이오매스는 자연에서 얻어진 화학적 에너지로 활용할 수 있으며 곡물, 식물, 동물과 미생물 등의 모든 유기체를 말한다. 별도의 처리과정을 거치지 않아도 재생 및 재활용이 가능하여 친환경적이며 주변에서 쉽게 얻을 수 있다는 이점이 있다. 한편, 바이오매스는 열분해 또는 발효 과정을 거쳐 바이오에너지 연료로 활용할 수 있다. 따라서 화석 연료의 고갈과 환경 영향 등의 문제 해결을 위한 대체 에너지 중 하나로 평가되고 있다. 본 연구에서는 바이오매스의 반탄화 처리가 가능한 523~573K의 온도 및 불활성 분위기 조건에서 다양한 바이오매스(톱밥, 볏짚, 쌀겨, 커피박, 폐목재) 내 탄소 함량을 높이는 공정을 진행하였다. 그리고, 반탄화한 바이오매스를 탄소 농도, 연소 거동 등을 조사하여 철강 산업 등에 활용할 수 있는 고체 연료로서의 가능성을 검토하였다.

• Journal of the Korean Wood Science and Technology
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• 제44권2호
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• pp.241-252
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• 2016

Cellulose acetate is one of well-known industrial materials which have various commercial uses. We treated the lignocellulosic biomass using two-step (steam explosion-chemical) reaction followed by acetylation to get the cellulose acetate in this study. The two-step treatment was done to improve the yields of acetylation of the substrates. The yields of the cellulose acetate were about 88.4, 88.1, and 151.7% in barley straw, rice straw, and oak tree, respectively. Also the degree of substitution (DS) of the acetates was 2.1 to 2.5 in the biomass. We found that the biomass were valuable cellulosic sources, including their derivatives, in this study. This means that the biomass can be converted into the high-valued cellulosic stuff.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1260-1268
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• 2013

A series of experiments were carried out with three native strains of microalgae to measure growth rates, biomass, and lipid productivities. Scenedesmus sp. IMMTCC-6 had better biomass growth rate and higher lipid production. The growth, lipid accumulation, and carbon dioxide ($CO_2$) consumption rate of Scenedesmus sp. IMMTCC-6 were tested under different NaOH concentrations in modified BBM. The algal strain showed the maximum specific growth rate (0.474/day), biomass productivity (110.9 mg $l^{-1}d^{-1}$), and $CO_2$ consumption rate (208.4 mg $l^{-1}d^{-1}$) with an NaOH concentration of 0.005 M on the $8^{th}$ day of cultivation. These values were 2.03-, 6.89-, and 6.88-fold more than the algal cultures grown in control conditions (having no NaOH and $CO_2$). The $CO_2$ fixing efficiency of the microalga with other alternative carbon sources like $Na_2CO_3$ and $NaHCO_3$ was also investigated and compared. The optimized experimental parameters at shake-flask scale were implemented for scaling up the process in a self-engineered photobioreactor. A significant increase in lipid accumulation (14.23% to 31.74%) by the algal strain from the logarithmic to stationary phases was obtained. The algal lipids were mainly composed of $C_{16}/C_{18}$ fatty acids, and are desirable for biodiesel production. The study suggests that microalga Scenedesmus sp. IMMTCC-6 is an efficient strain for biodiesel production and $CO_2$ biofixation using stripping solution of NaOH in a cyclic process.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.137-148
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• 2010

The high costs for ethanol production with lignocellulosic biomass as a second generation energy materials currently deter commercialization of lignocellulosic biomass, especially wood biomass which is considered as the most recalcitrant material for enzymatic hydrolysis mainly due to the high lignified structure and the nature of the lignin component. Therefore, overcoming recalcitrance of lignocellulosic biomass for converting carbohydrates into sugar that can subsequently be converted into biobased fuels and biobased products is the primary technical and economic challenge for bioconversion process. This study was mainly reviewed on the research trend of the enhancement of enzymatic hydrolysis for lignocellulosic biomass after pretreatment in bioethanol production process.

• 펄프종이기술
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• 제46권1호
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• pp.18-28
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• 2014

Renewable Portfolio Standards(RPS) is a regulation that requires a renewable energy generated from eco-friendly energy sources such as biomass, wind, solar, and geothermal. The RPS mechanism generally is an obligatory policy that places on electricity supply companies to produce a designated fraction of their electricity from renewable energies. The domestic companies to supply electricity largely rely on wood pellets in order to implement the RPS in spite of undesirable situation of lack of wood resources in Korea. This means that the electricity supply companies in Korea must explore new biomass as an alternative to wood. Palm kernel shell (PKS) and empty fruit bunch (EFB) as oil palm wastes can be used as raw materials used for making pellets after their thermochemical treatment like torrefaction. Torrefaction is a pretreatment process which serves to improve the properties including heating value and energy densification of these oil palm wastes through a mild pyrolysis at temperature typically ranging between 200 and $300^{\circ}C$ in the absence of oxygen under atmospheric pressure. Torrefaction of oil palms wastes at above $200^{\circ}C$ contributed to the increase of fixed carbon with the decrease of volatile matters, leading to the improvement of their calorific values over 20.9 MJ/kg (=5,000 kcal/kg) up to 25.1 MJ/kg (=6,000 kcal/kg). In particular, EFB sensitively responded to torrefaction because of its physical properties like fiber bundles, compared to PKS and hardwood chips. In conclusion, torrefaction treatment of PKS and EFB can greatly contribute to the implement of RPS of the electricity supply companies in Korea through the increased co-firing biomass with coal.

• 폴리머
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• 제38권4호
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• pp.464-470
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• 2014

A chemo-mechanical method was used to prepare lignin-containing cellulose nanofibrils(L-CNF) from unbleached woodpulps dispersed uniformly in an organic solvent. L-CNF/PLA composites were obtained by solvent casting method. The effects of L-CNF concentration on the composite performances were characterized by tensile test machine, contact angle machine, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The tensile test results indicated that the tensile strength and elongation-at-break increased by 50.6% and 31.8% compared with pure PLA. The contact angle of PLA composites decreased from $79.3^{\circ}$ to $68.9^{\circ}$. The FTIR analysis successfully showed that L-CNF had formed intermolecular hydrogen bonding with PLA matrix.

• 펄프종이기술
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• 제47권5호
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• pp.61-67
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• 2015

As the production of palm oil has been increased, the generation of oil palm biomass is also increased and the utilization of the oil palm biomass become more significant topic. One third of the oil palm biomass is empty fruit bunch (EFB) and the other two thirds are oil palm trunks and fronds. However, the effective use of oil palm biomass has not been developed and most of it is discarded near oil palm plants. In this study, we investigated the applicability of EFB to the paperboard mills, as an organic filler. The new organic filler was manufactured in a laboratory by grinding and fractionating dried EFB powder, and its properties were analyzed. The particles of EFB organic filler were larger and more spherical than those of the commercial wood powder. The use of EFB organic filler resulted in a higher bulk of the handsheets with similar trends of physical strength, compared to those made with wood powder. It was concluded that EFB could be used as a raw material to manufacture organic filler for paperboard production.