• 에너지공학
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• 제10권3호
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• pp.243-252
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• 2001

가압열중량분석기를 이용하여 비등온법에 의해 상온부터 100$0^{\circ}C$까지 온도를 상승시키면서 압력(1~l6기압)과 승온속도(heating rate, 15, 20, $25^{\circ}C$/min)의 변화에 따른 국내무연탄의 연소반응특성을 측정 및 해석하였다. 주어진 승온속도에서 압력이 증가함에 따라 반응속도가 증가하였으며 이와 같은 경향은 압력 증가에 따른 활성화에너지의 감소 때문으로 사료되었다. 압력이 1기압에서 16기압으로 증가함에 따라 Freeman과 Carroll$^{[11]}$ method에 의해 결정된 반응차수는 1.04에서 1.30차까지 선형적으로 증가하였으며 활성화에너지는 47.37㎉/mol에서 14.42kca1/mol로 감소하였다.

• 한국안전학회지
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• 제14권3호
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• pp.84-92
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• 1999

The effects of air velocity and excess air on combustion characteristics were studied in a fluidized bed combustor. The domestic low-grade anthracite coal with heating value of 2010 kcal/kg and the imported bituminous coal from Australia with heating value of 6520 kcal/kg were used as coal samples. The combustion characteristics of mixed fuels in a fluidized bed combustor could be interpreted by pressure fluctuation properties, ash distribution and gas emission. The properties of the pressure fluctuations, such as the standard deviation, cross-correlation function, dominant frequency and the power spectral density function, were obtained from the statistical analysis. From this study, the combustion region increased with increasing air velocity but decreased with excess air due to combustion characteristics of anthracite and bituminous coal.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.113-114
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• 2017

Recently, Subway workers have died from lung cancer. According to the Epidemiological Survey of the Welfare Corporation Institute of Pulmonary Disease of the Welfare Corporation, the family members applied for industrial accidents. The radon concentration in the subway work area was found to exceed 10 times the recommended standard value of 148 becquerels (Bq/㎥) in domestic multipurpose facilities. In addition, as a result of the national indoor radon concentration survey conducted by the Ministry of Environment in 2010 and 2013, housing was found to be over 100 becquerels (Bq/㎥) in 41% of the surveyed subjects. In addition, it was found that in 2012, 16.3% of villages exceeded the radon standard value in the survey on natural radioactive materials containing groundwater.

• 자원환경지질
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• 제32권1호
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• pp.113-121
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• 1999

Coal is both source rock and reservoir rock for the coalbed gas. Coalbed gas. Coalbed gas is predominantly methane and has a heating value of approximatly 1000 BTU/$ft^3$. Most of methane is stored in the coal as a monomolecular layer adsorbed on the internal surface of the coal matrix. The amount of methane stored in coal is related to the rank and the depth of the coal. THe higher the coal rank and the deeper the coal seam is presently buried, the greater its capacity to hold gas. Most of Korean Coal is anthracite or metaanthracite, Ro. 3.5~5.5%, and total reserves are 1.6 billion metric tons. The domestic demand for coal was drastically decreased and the rationalization policy carried out from 1987 on coal industry. Now that a large number of coal mines was closed only a few mines continued to produce not more than 5 million tons for year. It is therefore recommended to formulate a strategy to explore and exploit the resources of coalbed methane in Korea.

• 한국대기환경학회지
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• 제27권5호
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• pp.485-493
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• 2011

In Korea, PM (Particulate Matter) emissions caused by coal-fired power plants are measured by a system, so called Clean Air Policy Support System (CAPSS), which uses foreign emission factors. However, the system fails to reflect the characteristics of domestic power plants. In this regard, this study aims to develop local, accurate domestic emission factors. The study measured the amount of TSP (Total Suspended Particulates), PM10 and PM2.5 by collecting samples from the latter parts of pollution control devices which were installed at 3 bituminous-fired power plants and 3 anthracite-fired power plants. The results showed that the average concentrations of TSP, PM10 and PM2.5 measured at bituminous-fired power plants were 4.63 mg/$Sm^3$, 2.96 mg/$Sm^3$ and 3.07 mg/$Sm^3$ respectively, much higher than those from anthracite-fired power plants (2.96 mg/$Sm^3$, 2.47 mg/$Sm^3$ and 1.37 mg/$Sm^3$, respectively). In addition, bituminous-fired power plants showed higher ratios of PM10/TSP and PM2.5/TSP with 0.66 and 0.92, respectively, compared to 0.82 and 0.46, the ratios of PM10/TSP and PM2.5/TSP measured in anthracite-fired power plants. Emission factors based-on concentration measurements were also higher for bituminous-fired power plants, and PM with smaller particles tended to have bigger difference in emission factors between the two fuels. This study calculated the amount of PM emissions by using the estimated emission factors. When it comes to the PM emissions, it was less than that of CAPSS while similar to that of CleanSYS in its amount. It is expected that the emission factors developed by this study will be used in Korea replacing foreign emission factors currently used in Korea by ensuring the objectivity and reliability as domestic emission factors.

• 한국대기환경학회지
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• 제20권4호
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• pp.429-436
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• 2004

Circulating fluidized bed combustion (hereafter CFBC) technology enables an efficient combustion for the materials with low heating values such as high ash coal and sludges. It also has desulfation function by adding limestone directly to combustor. The CFBC has been considered as one of the best processes for low grade coal containing with large contents of ash and sulfur. In this paper, in order to various tests were performed to find the optimum desulfation condition for CFBC using Korean Anthracite. We surveyed possible parameters and conducted desulfation efficiency test in D Thermal Power Plant. In addition, the result of some fundamental theoretical consideration was discussed with CFBC. Optimum limestone size could be considered to be 0.1-0.3mm irrespective of combustion temperature and Ca/S molar ratio variation. Desulfation efficiency increased as the molar ratio increased. Because desulfation process occurs at the surface at higher temperature, inner side of limestone can＇t be utilized. When surface area is not appropriate, some SO$_2$ emit without reaction. Optimum molar ratio should be decided after considering chemical and physical properties of limestone and coal thoroughly such as particle size, pore size and HGI. Commercial CFBC is operated at Ca/S 1.6. Combustor temperature 840-87$0^{\circ}C$ shows good desulfation efficiency.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.230-233
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• 2008

The vanadium rich ash of petroleum coke can give a slagging problem during because of the high melting point of $V_2O_3$. For continuous removal of the slag, petroleum coke is often mixed with coal, and the viscosity of the mixed slag is an important property, determining the gasification temperature. The viscosities of the mixed slag from various mixing ratios of petroleum coke and a bituminous coal were investigated. When mixed with a crystalline coal slag, $T_{cv}$ was increased at a higher the coke content in the mixed feed. When the $V_2O_3$ concentration was greater than 4.5%, it was difficult to get accurate measurements of $T_{cv}$. The SEM/EDX analyses of the cooled slag revealed that the major crystalline phase was anorthite, and $T_{cv}$ should be related to the formation temperature of anorthite. The SEM/EDX analyses also showed that, at low concentrations of vanadium, part vanadium formed a crystalline phase with Al-Si-Ca-Fe, and the rest remained in the glassy phase, suggesting that vanadium existed as a slag component at the low viscosity region. At a high concentration, vanadium forms a phase with Ca, and the Ca-V phase was separated from the slag phase, and formed a layer above the slag. FeO in petroleum coke also played an important role determining viscosity: at high temperatures, increased FeO lowered the viscosity, but as it formed a spinel phase, the depletion of FeO in the slag resulted in a higher viscosity.

• 대한화학회지
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• 제4권1호
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• pp.78-80
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• 1957

Up to now, only superficial studies on the combustion velocity of smokeless fuels have been reported, while it should be a basical factor on the utilization of low quality coals and some other smokeless solid fuels. It was, therefore, difficult to choose raw material coals in manufacturing gaseous fuels. With the intent to solve above problem, we have determined combustion velocity of domestic anthracites, graphites, coalites of lignite and cokes from Japanese bituminous coal. The results show that the cokes from Japanese bituminous coal which has been used as raw material in the manufacturing gaseous fuels such as water gas, or producer gas in Korea can be replaced by some sources of domestic anthracite or coalite of lignite.

• 한국대기환경학회지
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• 제28권2호
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• pp.172-181
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• 2012

Mercury is one of the most hazardous air pollutants. Recently, mercury has been a concern in domestic and overseas because it has lethal toxicity, long distance transport, persistence and bioaccumulation in the environment. Stationary combustion sources such as coal-fired power plants, waste incinerators, and cement kilns are the major sources of mercury emissions. The objectives of this study were to measure the concentration for mercury from coal-fired power plants and to calculate emission factor to estimate its emission. The results showed that the mercury concentrations in the flue gas were 1.63-3.03 mg/$Sm^3$ in anthracite-fired power plants (average 2.32 mg/$Sm^3$) and 1.95-3.33 mg/$Sm^3$ in bituminous-fired power plants (average 2.6 mg/$Sm^3$). Mercury emission factor was estimated as 25.74 mg/ton for anthracite-fired power plants and 12.48 mg/ton for bituminous-fired power plants. Because actual measurements are limited in quantity, it is desirable to refine our estimates by extending the actual measurements.

• 대한환경공학회지
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• 제22권12호
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• pp.2141-2148
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• 2000

본 연구는 무연탄올 원료로 제조한 활성탄의 활성화 시간과 burn-off에 따른 세공구조의 변화를 고찰한 것으로 77K에서 질소 흡착실험에 의해 특성을 분석했다. 활성화 시간의 증가에 따라 burn-off는 거의 선형적으로 증가하며, burn-off를 증가시킴에 따라 제조된 활성탄의 총세공부피와 BET 비표면적은 증가했다. $800^{\circ}C$의 활성화는 $950^{\circ}C$의 활성화에 비해 미세세공(micropore)을 많이 생성시켰고, 동일한 burn-off에서는 저온에서 활성화시킨 활성탄에 미세세공이 발달하고 고온에서 활성화시킨 활성탄에 중간이상의 세공이 더 발달해 있었다. 수증기 활성화에 의해서는 직경 $100{\AA}$ 이하의 세공이 주로 발달되었으며 특히 $6{\sim}40{\AA}$ 범위의 세공은 burn-off의 정도에 따라 상당히 발달됨을 알 수 있었다.