• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.157-162
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• 2018

In the study, herbaceous biomass waste including giant miscanthus, corn stalk, and wheat stalk were used to prepare commercially valuable activated carbons by KOH activation. The waste biomass predominantly consists of cellulose/hemicellulose and lignin, in which decomposition after carbonization and activation contributed to commercially valuable specific surface areas (>$2000m^2/g$) and specific capacitances (>120 F/g) that exceeded those of commercial activated carbon. The significant electrochemical performance of the herbaceous biomass-derived activated carbons indicated the feasibility of utilizing waste biomass to fabricate energy storage materials. Furthermore, with respect to both economic and environmental perspectives, it is advantageous to obtain activated carbon from herbaceous biomass waste given the ease of handling biomass and the low production cost of activated carbon.

• Journal of Electrochemical Science and Technology
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• 제9권3호
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• pp.163-168
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• 2018

Biomass waste-derived carbon is an attractive alternative with environmental benignity to obtain carbon material. In this study, we prepare carbon from coffee grounds as a biomass precursor using a simple, inexpensive, and environmentally friendly method through physical activation using only steam. The coffee-derived carbon, having a micropore-rich structure and a low extent of graphitization of disordered carbon, is developed and directly applied to lithium-ion battery anode material. Compared with the introduction of the Ketjenblack (KB) conducting agent (i.e., coffee-derived carbon with KB), the coffee-derived carbon itself achieves a reversible capacity of ~200 mAh/g (0.54 lithium per 6 carbons) at a current density of 100 mA/g after 100 cycles, along with excellent cycle stability. The origin of highly reversible lithium storage is attributed to the consistent diffusion-controlled intercalation/de-intercalation reaction in cycle life, which suggests that the bulk diffusion of lithium is favorable in the coffee-derived carbon itself, in the absence of a conducting agent. This study presents the preparation of carbon material through physical activation without the use of chemical activation agents and demonstrates an application of coffee-derived carbon in energy storage devices.

• Asian Journal of Atmospheric Environment
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• 제11권2호
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• pp.79-95
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• 2017

A number of field studies have provided evidence that biomass burning is one of the major global sources of atmospheric particles. In this study, we have collected $PM_{2.5}$ emitted from biomass burning combusted at open burning and laboratory chamber situations. The open burning experiment was conducted with the cooperation of 9 farmers in Chiba Prefecture, Japan, while the chamber experiment was designed to evaluate the characteristics of chemical components among 14 different plant species. The analyzed categories were $PM_{2.5}$ mass concentration, organic carbon (OC), elemental carbon (EC), ionic components ($Na^+$, ${NH_4}^+$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Cl^-$, ${NO_3}^-$ and ${SO_4}^{2-}$), water-soluble organic carbon (WSOC), water-insoluble inorganic carbon (WIOC), char-EC and soot-EC. OC was the dominant chemical component, accounting for the major fraction of primary $PM_{2.5}$ derived from biomass burning, followed by EC. Ionic components contributed a small portion of $PM_{2.5}$, as well as that of $K^+$. In some cases, $K^+$ is used as biomass burning tracer; however, the observations obtained in this study suggest that $K^+$ may not always be suitable as a tracer for biomass burning emissions. Also, the results of all the samples tested indicate relatively low values of char-EC compared to soot-EC. From our results, careful consideration should be given to the usage of $K^+$ and char-EC as indicators of biomass burning. The calculated ratios of WSOC/OC and WIOC/OC were 55.7% and 44.3% on average for all samples, which showed no large difference between them. The organic materials to OC ratio, which is often used for chemical mass closure model, was roughly estimated by two independent methods, resulting in a factor of 1.7 for biomass burning emissions.

• 청정기술
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• 제28권2호
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• pp.174-181
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• 2022

바이오매스는 현재 석유, 천연가스, 석탄 등 화석 연료에서 얻을 수 있는 액체 연료와 유기 화합물을 생산할 수 있는 지속 가능한 대체 자원이다. 화석 연료를 사용하면 온실가스를 배출하기 때문에 바이오매스와 같은 탄소중립적 원료를 사용하는 것은 기후 변화 대응에 기여할 수 있다. 바이오매스 원료로부터 석유 대체 화학 제품과 연료를 생산하기 위한 생물학적 및 화학적 공정이 제안되었지만, 바이오매스에 포함된 높은 산소 함량때문에 화석 연료를 완전히 대체하기 어렵다. 석유와 유사한 연료와 화학 물질을 생산하려면 바이오매스 파생물에 존재하는 산소 원자를 제거하거나 산소 기능기를 전환해야 하며, 이는 촉매 화학적 수첨탈산소화에 의해 달성될 수 있다. 바이오매스 열분해 오일, 리그노셀룰로오스 유래 화학물질, 지질과 같은 원료를 탈산소 연료 및 화학물질로 전환하기 위해 수첨탈산소화가 진행되었다. 높은 표면적의 금속 산화물 또는 탄소에 지지된 귀금속 및 전이 금속으로 구성된 다기능성 촉매는 효율적인 수첨탈산소 촉매로 사용되었다. 본 총설에서는 문헌에서 제안된 촉매를 확인하고 이러한 촉매를 이용한 수첨탈산소 반응 시스템이 논의하였다. 문헌에 보고된 수첨탈산소화 방법을 기반으로, 실현 가능한 수첨탈산소화 공정 개발 방향이 제시하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.285-285
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• 2015

Utilization of biomass as a substitute fuel for conventional energy systems have been grown larger everyday in the world. In particular, co-firing of biomass in a large coal power plant are common in Korea after the introduction of RPS since 2012, and the application of biomass-derived fuel is now spreading to district heating and power, industrial energy supply, and transportation sectors. For biomass to energy, appropriate conversion process is needed to satisfy the fuel requirements of a specific energy system. In this study, various kinds of thermochemical conversion technologies will be presented for renewable fuel productions from biomass.

• 한국산림과학회지
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• 제96권5호
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• pp.591-601
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• 2007

Spatial information on forest biomass is an important factor to evaluate the capability of forest as a carbon sequestrator and is a core independent variable required to drive models which describe ecological processes such as carbon budget, hydrological budget, and energy flow. The objective of this study is to understand the relationship between satellite image and field data, and to quantitatively estimate and map the spatial distribution of forest biomass. Landsat Enhanced Thematic Mapper (ETM+) derived vegetation indices and field survey data were applied to estimate the biomass distribution of mountainous forest located in Gwangneung Experimental Forest (230 ha). Field survey data collected from the ground plots were used as the dependent variable, forest biomass, while satellite image reflectance data (Band 1~5 and Band 7), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and RVI (Ratio Vegetation Index) were used as the independent variables. The mean and total biomass of Gwangneung catchment area were estimated to be about 229.5 ton/ha and $52.8{\times}10^3$ tons respectively. Regression analysis revealed significant relationships between the measured biomass and Landsat derived variables in both of deciduous forest ($R^2=0.76$, P < 0.05) and coniferous forest ($R^2=0.75$, P < 0.05). However, there still exist many uncertainties in the estimation of forest ecosystem parameters based on vegetation remote sensing. Developing remote sensing techniques with adequate filed survey data over a long period are expected to increase the estimation accuracy of spatial information of the forest ecosystem.

• Asian Journal of Atmospheric Environment
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• 제11권3호
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• pp.165-175
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• 2017

In Japan, the primary carbonaceous particles emitted from motor vehicles and waste incinerators have been reduced due to strict regulations against exhaust gas. However, the relative contribution of carbonaceous particles derived from plants and biomass has been increasing. Accordingly, compositional analysis of carbonaceous particles has become increasingly important to determine the sources and types of particles produced. To reveal the sources of the organic particles contained in particulate matter with diameters of ${\leq}2.5{\mu}m$ ($PM_{2.5}$) and the processes involved in their generation, we analyzed molecular marker compounds (2-methyltetrols, cis-pinonic acid, and levoglucosan) derived from the plants and biomass in the $PM_{2.5}$ collected during daytime- and nighttime-sampling periods in summer (July and August) and autumn (November) in Kazo, which is in the northern area of Saitama prefecture, Japan. We also measured $^{14}C$ carbonaceous concentrations in the same $PM_{2.5}$ samples. The concentrations of 2-methyltetrols were higher in the summer than in the autumn. Because the deciduous period overlaps with this decrease in the levels of 2-methyltetrols, we considered the emission source to broad-leaved trees. In contrast, the emission source of the cis-pinonic acid precursor was considered to be conifers, because its concentration remained almost constant throughout the year. The concentration of levoglucosan was considerably increased in the autumn due to frequent biomass open burning. The ratio of plant-derived carbon to total carbon, obtained by measuring of $^{14}C$, in summer $PM_{2.5}$ sample was higher in the nighttime, and could be influenced by anthropogenic sources during the daytime.

• Journal of Forest and Environmental Science
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• 제27권3호
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• pp.183-194
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• 2011

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

• 한국환경농학회지
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• 제35권3호
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• pp.159-165
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• 2016

과수원에서 발생하는 전정가지 부산물로부터 생산한 바이오매스 탄화물의 토양내 처리효과를 구명하기 위하여 배 전정가지를 활용하여 탄화물을 생산하고 이를 배 과원 토양에 투입하여 토양 화학성 변화와 토양 탄소 저장 잠재량을 비교 검토하였다. 배 전정가지 유래 탄화물은 방향족 화합물 형태를 유지하고 탄소함량도 62%로 매우 높았으며, 과원 토양의 유기물함량은 탄화물의 투입량이 많을수록 통계적으로 유의하게 증가하였다. 탄화물 투입 166일 후 토양 탄소저장 잠재량은 바이오매스 탄화물 시용 수준이 높을수록 증가하는 경향을 나타냈으며, 통계적으로 유의한 차이를 나타냈다. 대조구, C-1 그리고 C-2 처리구에서 각각 토양 탄소저장 잠재량은 40.1, 49.3 그리고 57.8 Mg/ha으로 나타났다. 토양 탄소저장 잠재량은 탄화물 투입량에 따라 고도로 높은 상관관계 (P < 0.001)를 나타내며 증가하였다. 기울기가 1.496인 1차 회귀방정식을 나타냈으며, 탄화물 투입량이 100 kg/ha 높아질수록 토양 탄소 저장 잠재량은 0.1496 Mg/ha 증가하였다. 이러한 결과를 미루어 볼 때 장기간 동안 지속적으로 바이오매스 탄화물을 시용한다면 토양 탄소의 중요한 공급원이 되며 결론적으로 농경지가 토양 탄소저장원으로서의 역할을 할 수 있을 것으로 판단된다.

• 유기물자원화
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• 제31권3호
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• pp.27-34
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• 2023

본 연구에서는 여러 종류의 식물성 바이오매스 폐기물을 리튬이온전지용 음극활물질로 재활용하고자 하였다. 수거한 바이오매스는 세척 및 분쇄 후 질소 환경(850℃)으로 탄화하였으며, 이를 FE-SEM, EDS, FT-IR을 사용하여 물리·화학적 특성을 비교하였다. 바이오매스 기반의 탄소 전구체로 왕겨, 밤껍질, 녹차 티백, 커피 폐기물을 사용했으며, 전구체의 성분에 따라 형태 및 탄소화 정도의 차이가 발생함을 확인하였다. 바이오매스 폐기물로 제조된 탄소를 음극재로 활용하여 전기화학 성능을 비교한 결과 각각 65.8, 80.2, 90.6, 104.7mAh g^-1의 방전용량을 나타내었으며, 커피 폐기물을 전구체로 제조한 탄소가 가장 높은 방전용량을 나타내었다. 이는 바이오매스의 원소 조성 및 구성성분 차이로 인해 탄화 정도가 달라지기 때문이다. 최종적으로, 환경오염을 유발하는 다양한 식물성 바이오매스를 탄화를 통해 효과적인 에너지 저장매체로 활용할 수 있는 가능성을 제시하였다.