• Korean Chemical Engineering Research
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• 제51권6호
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• pp.739-744
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• 2013

본 연구에서는 낙엽송의 연료특성 향상을 위해 반탄화를 수행하였으며 반응표면분석에 의해 반탄화 최적조건을 탐색하였다. 반탄화는 반응온도($220{\sim}280^{\circ}C$)와 반응시간(20~80분)에 따라 수행하였다. 반탄화 온도가 증가할수록 처리된 바이오매스의 탄소함량은 49.36%에서 56.65%로 증가한 반면, 수소와 산소의 함량은 각각 5.56%에서 5.48%, 37.62%에서 31.67%로 감소하였다. 반탄화 처리 후 바이오매스의 중량감소율 및 발열량은 반탄화 정도(SF)에 따라 증가하였다. 가장 높은 반탄화 정도(SF 7)에서 26.58%의 중량감소율을 나타났으며, 발열량은 22.30 MJ/kg으로 처리 전 바이오매스와 비교하여 20.41% 증가하였다. 에너지수율은 반탄화 정도(SF)가 높아질수록 감소하는 경향을 나타냈으며, 높은 발열량 증가와 낮은 중량감소율에서 가장 높은 에너지수율을 나타냈다(SF 5.72).

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1678-1686
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• 2020

본 논문은 농업부산물인 왕겨를 사용하여 목제펠릿 이용 가능성을 도출하고자 하였으며 왕겨의 낮은 발열량은 팽연화 기술과 연소첨가제를 통해 개선하고자 하였다. 왕겨의 물리?화학적 분석 시 염소 함유량이 0.09%로 목재펠릿 품질 기준에 부합하지 않는 결과를 얻을 수 있었다. 팽연화 기술을 통해 왕겨를 팽연왕겨로 제작 시 염소 함유량이 감소하여 목재펠릿 기준에 준하는 0.02%의 생성물을 얻을 수 있었으며 발열량 역시 기존 3,780 kcal/kg 대비 4,280 kcal/kg로 증가된 생성물을 얻을 수 있었다. 5,000 kcal/kg 이상의 생성물을 얻기 위해 연소촉진제로 붕사, 과산화수소, 수산화나트륨을 사용했지만 발열량 개선은 미비하게 나타났다. 폐자원 바이오매스인 커피찌꺼기를 사용하여 커피유로 전환 후 팽연왕겨에 혼합하여 생성물 분석 시 커피유 15 wt% 혼합 생성물이 4,949 kcal/kg의 발열량을 나타냈다. 농업부산물인 왕겨를 목제펠릿으로 사용할 시 발열량 개선을 위해 폐자원을 사용하는 것이 바람직하다 판단되며, 본 연구의 결과에 따라 커피유를 혼합할 시 왕겨를 목제펠릿으로 충분히 사용 가능할 것이라 사료된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.31-34
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• 2003

Sandwich panel is composed of the facing sheets which support the external load, the cellular core with the low thermal conductivity and the adhesive agent to bond them. The cellular core was produced by binding lightweight cellular aggregates with cement and two types of acrylic base St/BA emulsion were added with a view to improving the workability ion due to high absorption of light weight aggregate and to develope more strength, respectively. This investigation is to comprehend the effect of the addition of two types of St/BA on thermal conductivity, calorific value and exhaustion content of noxious gas in addition re compressive and flexural strength. Flexural strength of the specimen made with St/BA-2 ranged 20kgf/cm2 to 25kgf/cm2 and was about 50% to 100% as high as that of the non-fiber specimen. Thermal conductivity was recorded from 2.0 to 3.0 kcal/mh$^{\circ}C$ and calorific value of St/BA modified specimen was much lower than that of commercial sandwich panel core of EPS and urethane. Careful caution has to be taken because generation of noxious gas such as CO, NO and SO2 tend to increase with addition of polymer cement ratio.

• Agricultural and Biosystems Engineering
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• 제3권2호
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• pp.79-84
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• 2002

The seawater involving diverse chemical elements was mixed with wasted coals to improve the quality. The thermal and chemical characteristics of these seawater-mixed coals were investigated and compared with those of original coals. The contents of MgO, $Na_2O$, and $K_2O$ were increased by mixing seawater in wasted coals. The content of $Na_2O$ in these coal samples was greatly increased due to the sodium, which was the main component of seawater. Thus, it was expected that fusion temperatures of these coal samples were decreased. Coal samples mixed with seawater showed that the rapid weight loss was started at the lower temperature than those of original coal samples. In these coal samples, the temperatures of maximum heat emission were lowered by average $61^{\circ}C.$. Thus, it is suggested that some chemical constituents of the seawater act an important role on lowering the ignition temperature of wasted coal. By mixing seawater into wasted coals, the calorific values were increased. Especially, calorific values were greatly increased in the coal samples of lower quality as Baksan A and B with the improvement of 15~20%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.75-78
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• 2006

With the increasing environmental consideration and stricter regulations waste gasification is considered to be more attractive technology than conventional incineration for energy recovery as well as material recycling. The experiment for combustible waste was performed In the fixed bed gasifier to investigate the gasification behavior with the operating conditions in a 5ton/day fixed bed gasifier The experiments of operation with 10-50 hours were carried out to determine the effects of bed temperature and oxygen/waste rat io on the syngas composition, calorific value and carbon conversion. The calorific values of the produced syngas decreased with an Increase of bed temperature because combust ion reaet ion more act ively happened. The syngas composition of wood waste gasification is CO: 34.4%, $H_2: 10.7%,\;CH_4: 6.0%,\;CO_2: 48.9%$ and that of RPF is CO: 33.9%, $H_2: 26.1%,\;CH_4: 10.7%,\;CO_2: 29.2%$. The average calorific values of produced gas were about $1,933kcal/Nm^3,\;2,863kcal/Nm^3$, respectively

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 춘계학술대회 논문집
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• pp.422-423
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• 2006

• The Korean Journal of Ecology
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• 제13권3호
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• pp.203-214
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• 1990

The work reported here aims to assess how Knots, Calidris canutus, accumulate rapidly large energy and nutrient reserve at Red Car in England. Most of Knots in England belong to long billed, long winged population compare with subspecies in Korea. The rate of prey intake of Knot increases as a nearest neighbour distance decreases. Foraging rate and vigilance rate increases as flock size decreases. The calorific value of each sized of Common Mussel Mytilus edulis, main food species of Knot, are almost same each other but the calorific content of each size Mussels are quite different each other. The rate of daily energy intake of Knots have been estimated from 192 kcal to 270 kcal.

• 한국농공학회논문집
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• 제46권3호
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• pp.85-92
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• 2004

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce significant amount of energy from biomass around the world. In spite of the potential, there are a few efforts in biomass utilization in this nation. In this study, elemental biomass data was obtained with respect to the amount and calorific values of agricultural residues. Rice straw and husks were not included in the evaluation due to their demand from alternative uses such as livestock feedings, bedding materials, and so forth. Dry basis high calorific values are about 4,500 kcal/kg for all the agricultural residues investigated, similar to literature data. Energy densities or unit area energy value, from pepper and sesame were significant and comparable to those of woody biomass. These elemental data for biomass resources will Provide the background of Planning and development of biomass energy Program, which is getting more feasible along with advances in energy conversion technologies such as micro gas turbines.

• Journal of Biosystems Engineering
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• 제33권2호
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• pp.124-129
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• 2008

In this study, fuel qualities including kinematic viscosity and pour point in the various temperature, calorific value and combustion characteristics of two biodiesels based on the soybean and waste oil blended with light oil were investigated and discussed in order to figure out to confirm fuel compatibility taking the place of light oil in the hot air heater or boiler. As biodiesel content ratio increased calorific value of biodiesel decreased, and the difference was 13% between 100%-biodiesel and light oil. In general, pour points of the biodiesels were higher than light oil, and as biodiesel content ratio increased pour point increased. About 15 cSt was the pour point of biodiesels and light oil, which occurred at 3 to $4^{\circ}C$ in the biodiesels and $-25^{\circ}C$ in the light oil. Flame dimensions of biodiesels and light oil were almost same at the same combustion condition in the burner of the hot air heater. CO concentrations in the exhaustion gas were far lower than those of the light oil. Though pour point of biodiesel is a little inferior to light oil, still biodiesel can be an alternative fuel substituting for light oil in combustion system without much modifying the current oil combustion mechanism.

• 자원환경지질
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• 제22권2호
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• pp.141-150
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• 1989

In order to make economic and geological evaluation of coal in Korea, proximate and ultimate analyses were carried out as well as coal petrological studies such as maceral analyses, vitrinite reflectance and sporinite fluorescence measurement. The coeffcient of correlation between each factor of both conventional utilization and coal petrological parameters were studied as in Table 5 and 6. Their conclusions were as follow: (1) for anthracite, the good parameters of coal rank are mean vitrinite reflectance, carbon content, hydrogen content and H/C atomic ratio: (2) for brown coal and sub-bituminous coal, the good parameters of coal rank are carbon content, calorific value, moisture content, hydrogen content, oxygen content and O/C atomic ratio as well as vitrinite reflectance and sporinite fluorescence. An attempt is made to infer the coalforming environment by utilization of coal petrological analyses and to make comparison of coal analyses with proximate and ultimate analyses throughout the island arc region including Japan, Philippine and Indonesia and continental region including USA, Canada and Australia. As a result, meceral composition of Paleozoic and Mesozoic anthracite are similar to that of the Paleozoic continental coals, which were formed under dry conditions or low water table, but the coalification degree suddenly increased during Daebo orogeny (middle Jurassic to lower Cretaceous). The Tertiary coal resembles those of Tertiary island arc region coal characterized by higher calorific value, volatile matter content and H/C atomic ratio and by the formation of coal under wet conditions or higher water table.