• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.952-961
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• 2019

Chlorella spp. are green algae that are found across wide-ranging habitats from deserts to arctic regions, with various strains having adapted to survive under diverse environmental conditions. In this study, two novel Chlorella strains (ABC-002, ABC-008) were isolated from a freshwater lake in South Korea during the winter season and examined for possible use in the biofuel production process. The comparison of ABC-002 and ABC-008 strains with Chlorella vulgaris UTEX265 under two different temperatures ($10^{\circ}C$, $25^{\circ}C$) revealed their cold-tolerant phenotypes as well as high biomass yields. The maximum quantum yields of UTEX25, ABC-002, and ABC-008 at $10^{\circ}C$ were 0.5594, 0.6747, and 0.7150, respectively, providing evidence of the relatively higher cold-resistance capabilities of these two strains. Furthermore, both the biomass yields and lipid content of the two novel strains were found to be higher than those of UTEX265; the overall lipid productivities of ABC-002 and ABC-008 were 1.7 ~ 2.8 fold and 1.6 ~ 4.2 fold higher compared to that of UTEX265, respectively. Thus, the high biomass and lipid productivity over a wide range of temperatures indicate that C. vulgaris ABC-002 and ABC-008 are promising candidates for applications in biofuel productions via outdoor biomass cultivation.

• Elastomers and Composites
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• 제52권4호
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• pp.249-256
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• 2017

The history of polyurethane is relatively shorter compared to that of the other polymers, though its importance has grown rapidly. Due to its unique properties, polyurethanes are widely applied in various fields. In particular, the automotive industry is one of the important application fields. To date, polyols and isocyanates used in the polyurethane industry are generally of petrochemical origin. Recently, owing to the oil crisis, legislation, and growing awareness towards environmental preservation, the demand for more sustainable and eco-friendly raw materials has increased. In this paper, the latest research and development trends in polyurethane applications were reviewed, with a focus on the automobile industry in areas such as seat comfort, noise reduction, light weight, biomass-based polyurethane, and recycling.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.375-378
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• 2014

In this study, we carried out torrefaction experiment using PKS(Palm Kernel Shell), and Bagasse as a raw material of oversee of herbaceous biomass and using waste wood and logging residue as a raw material of domestic of woody biomass. And then, by analyzing the physical & chemical properties, we investigated the characteristics as a fuel. By using the result of thermo gravimetric analysis, the biomass residue was torrefied for 30 minutes at a temperature range of $250-350^{\circ}C$ in anaerobic condition. As a result, torrefied materials of moisture content are lower than raw, but of fixed carbon, calorific value and ash are higher than raw.

• 한국환경과학회지
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• 제29권2호
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• pp.155-166
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• 2020

This study was conducted to analyze the current situation of the logging operation system and to suggest an effective policy plan to secure important raw materials for the use of forest biomass. The dissemination of forestry mechanization and the establishment of the logging operation are important tasks to establish a system and reduce costs of timber production by increasing the use of forest biomass; this includes increasing the supply of timber for domestic products and increasing the production of wood chips and wood pellets. In particular, the efficiency of steep-slopes catenary system machinery for yarding such as tower-yarder and swing-yarder should be urgently supplied to cope with forest production and supply of forest biomass energy resources. In addition, it is necessary to continuously promote the dissemination of high-performance forestry machinery as is being done in Japan. At the same time, instead of distributing or retaining the spread of forestry machinery to the state and local governments, it is necessary to distribute timber production work centered on forest cooperatives or private timber producers to be carried out by wood producers, forest cooperatives and individuals.

• KSBB Journal
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• 제27권3호
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• pp.137-144
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• 2012

Among various pretreatment processes for bioethanol production, extrusion pretreatment, one of cheap and simple process was investigated to efficiently produce fermentable sugars from micro alga, Chlorella sp. The biomass was pretreated in a single screw extruder at five different barrel temperatures of 45, 50, 55, 60 and $65^{\circ}C$, respectively with five screw rotation speed of 10, 50, 100, 150 and 200 rpm. The pretreated biomass was reacted with two different hydrolyzing enzymes of cellulase and amyloglucosidase since the biomass contained different types of carbohydrates, compared to cellulose of agricultural by-products such wheat and corn stovers, etc. In general, higher glucose conversion yield was obtained as 13.24 (%, w/w) at $55^{\circ}C$ of barrel temperature and 100 rpm of screw speed conditions. In treating 5 FPU/glucan of cellulase and 150 Unit/mL of amyloglucosidase, ca. 64% of cellulose and 40% of polysaccharides in the micro alga were converted into glucose, which was higher yields than those from other reported data without applying an extrusion process. 84% of the fermentable sugars obtained from the hyrolyzing processes were fermented into ethanol in considering 50% of theoretical maximum fermentation yield of the yeast. These results implied that high speed extrusion could be suitable as a pretreatment process for the production of bioethanol from Chlorella sp.

• 자원리싸이클링
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• 제30권1호
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• pp.77-82
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• 2021

철강 산업에 있어서 CO2 배출량 감소는 중요한 이슈이며, CO2 배출 감소를 위해 코크스를 일부 대체할 수 있는 탄재 연료의 연구는 필요하다. 한편, 바이오매스 연료는 고정 탄소를 일부 함유하고 있으며, 반탄화 공정을 통해 연료내 탄소의 함량을 증가시킬 수 있다. 바이오매스 연료 중 커피박은 약 55 mass%의 탄소를 함유하고 있으며, 국내에서 연간 약 27만 ton이 매립 또는 소각되고 있다. 또한, 연간 커피 소비량의 증가로 인한 재활용 공정에 관한 연구가 필요하다. 본 연구에서는 반탄화 공정을 통한 커피박 내 고정 탄소의 농도에 미치는 온도의 영향을 연구하였다. 또한, 반탄화 커피박의 용해 실험을 통해 금속 샘플 내 탄소 농도와 용해 효율에 대한 코크스와 혼합비의 영향을 조사하였다.

• 한국환경농학회지
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• 제30권3호
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• pp.252-260
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• 2011

국내의 바이오매스 자원조사에 대한 연구에서 농업부산물의 경우 잠재 이용량이 가장 높은 부분임에도 불구하고 과거 자료를 근거로 인용되어 잠재발생량이 산출되고 있다. 따라서 국가 단위의 바이오매스 인벤토리의 구축이 요구되고 신뢰도와 재현성이 높은 바이오매스 환산계수 개발을 통해 효과적인 자원관리가 이루어져야 한다. 본 연구에서 포장시험을 통해 산정된 8종류의 농작물의 바이오매스 환산계수를 산정하였고, 2004~2008년 평균 곡물 총 생산량을 기준으로 농작물 18종의 바이오매스 환산계수를 산정하여 2009년 농업 유래 바이오매스 잠재 발생량을 추정하였다. 그 결과 농작물에서 발생되는 바이오매스량은 연간 약 11,600 천톤이었고, 이 중 볏짚의 발생량이 연간 약 6,507 천톤, 왕겨 1,140 천톤으로 농업부문에서 약 75%를 차지하였으며, 고추 줄기가 1,003 천으로 약 10%를 차지하였고, 사과 전정가지가 약 6%인 620천톤 정도가 발생되는 것으로 추정되었다. 그러나 볏짚과 왕겨의 경우 기존에 가축 사료나 축사 깔짚 등으로 재이용되고 있기 때문에 실제 바이오매스 에너지원으로의 활용 측면은 낮을 것으로 예상된다. 또한, 농업부산물의 에너지화를 위해서 잠재 발생량의 정확한 산정도 필요하지만 농업부산물의 특성상 시기별 발생량과 종류가 달라지기 때문에 계절 등에 따른 바이오매스 발생특성을 고려해야 한다. 과수 전정가지 등 과수 부산물의 경우 1~3월 사이에 발생이 집중되는 것으로 나타났고, 맥류와 서류 및 유채 등이 4~6월에 발생되었으며, 미곡 등 다른 부산물의 9, 10월에 집중하여 발생되는 것으로 나타났다. 따라서 농촌지역 바이오매스의 효율적인 이용을 위해서는 바이오매스의 연중 안정된 수급 및 보급 가능한 이용체계 확립이 우선되어야 할 것으로 사료된다.

• Journal of Ecology and Environment
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• 제31권2호
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• pp.115-123
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• 2008

We describe plant biomass in the grasslands of the Mongolian steppe obtained using a quadrat sampling technique. Four sites were studied in the northeastern Mongolia located between $47^{\circ}12'N$ and $47^{\circ}40'N$ and $102^{\circ}22'E$ and $112^{\circ}24'E$, which were typical grasslands of the steppe. Biomass, carbon and nitrogen content were determined for the plants collected from the grazed and ungarazed stands. With the measurements above, we expect to obtain information on grazing effects on the grasslands and carbon sequestration of the grassland from the air. In order to estimate the biomass without destroying the stands, we derived an equation to describe the relationship between plant biomass and v-value using plant height and species coverage within the stand. Estimated plant biomass in the ungrazed and grazed stands ranged between $108.0\;g\;m^{-2}$ and $13.4\;g\;m^{-2}$ and between $97.5\;g\;m^{-2}$ and $14.1\;g\;m^{-2}$ in late June 2005, respectively. Litter in the ungrazed and grazed stands ranged from $330.3\;g\;m^{-2}$ to $78.4\;g\;m^{-2}$ and from $188.0\;g\;m^{-2}$ to $20.3\;g\;m^{-2}$, similarly. Average carbon and nitrogen contents in plants and in litter were 43.0% and 1.9% and 33.7% and 1.4%, respectively. In study sites at Baganuur, the carbon and nitrogen content of plant materials (plant plus litter) was $118.4\;g\;m^{-2}$ and $4.7\;g\;m^{-2}$ on 30 June 2005.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.61-64
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• 2013

Biomass is well known for organic resources photosynthesized by carbon dioxide water in the air and thus it can be widely used in the form of energy and production for various kinds of materials. Through pyrolysis, biomass can be transformed into solid(biochar), liquid(bio-oil), and combustible gas on the different condition of temperature and heating rate. That's why biomass can be practically used to preprocess and produce a variety of elements. This work is to analyze the characteristics of slow pyrolysis of three different kinds of biomass extracted from Indonesia. They showed similar moisture content and combinations of combustible matters and had quite a large discrepancy in the ash among them like 2.1 & of Bagasse, 91% of PKS, and 20.9% of Paddy Straw, respectively. yield of biochar, solid form of the biomass, steadily decreased when the temperature went up and that of bio-oil the highest at the temperature of 500 degrees Celsius. At the same temperature range, PKS bio-oil showed 51.4 % of yield and Bagasse had 55.1% while it turned out that Paddy straw showed the lowest yield of 37.2%. The apparent density was also measured to figure out the density of each product from the pyrolysis experiments at the temperature of 500 degrees Celsius. The result was like these; the density of biochar was 0.17, the lowest, and that of Tree stem was 1.3 when mixed by an equal amount of biochar and bio-oil.

• ALGAE
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• 제28권1호
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• pp.101-109
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• 2013

Some Chlorella species grow heterotrophically with organic substrate in dark condition. However, heterotrophic Chlorella species are limited and their optimum culture conditions are not fully known. In this study, three heterotrophic Chlorella species, two strains (C4-3 and C4-4) of C. vulgaris and one Chlorella sp. (C4-8) were examined on optimum culture conditions such as carbon source, temperature, and concentrations of nitrogen and phosphorus in Jaworski's medium (JM). And the growth and fatty acid composition of Chlorella were analyzed. For three heterotrophic Chlorella species, glucose (1-2%) as a carbon source only increased the growth and the range of optimum culture temperature was $26-28^{\circ}C$. Doubled concentrations of the nitrogen or phosphorus in JM medium also improved the growth of Chlorella. Chlorella cultured heterotrophically showed significantly higher growth rate and bigger cell size than those autotrophically did. C. vulgaris (C4-3) cultured heterotrophically showed the highest biomass in dry weight ($0.8g\;L^{-1}$) among three species. With respect to fatty acid composition, the contents of C16:0 and n-3 highly unsaturated fatty acid (HUFA) were significantly higher in autotrophic Chlorella than in heterotrophic one and those of total lipid were not different between different concentrations of nitrogen and phosphorus in JM medium. Among three Chlorella species in this study, C. vulgaris (C4-3) appeared to be the most ideal heterotrophic Chlorella species for industrial application since it had a high biomass and lipid content.