• 한국환경보건학회지
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• 제36권2호
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• pp.128-135
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• 2010

The main purpose of this study was to develop the greenhouse gas emission factor for power plant using sub-bituminous coal. In Korea, Fired power plant are a major source of greenhouse gases within the fossil fuel combustion sectors, thus the development of emission factors is necessary to understand the characteristics of the national specific greenhouse gas emission and to develop nation specific emission factors. These emission factors were derived from the $CO_2$ concentrations measurement from stack and fuel analysis of sub-bituminous coal. Caloric value of sub-bituminous coal used in the power plants were 5,264 (as received basis), 5,936 (air-dried basis) and 6,575 kcal/kg (dry basis). The C emission factors by fuel analysis and $CO_2$ concentration measurement was estimated to be 26.7(${\pm}0.9$), 26.3(${\pm}2.8$)tC/MJ, respectively. Our estimates of C emission factors were comparable with IPCC default value.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.111-114
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• 2012

The ignition behavior of single coal particles of five kindes of coal with different ranks (low volatile bituminous, low volatile sub-bituminous, high volatile bituminous, lignite) with particle size of $150-200{\mu}m$ was investigated at high heating rate condition. Particles were injected into a laminar flow reactor and the ignition behavior was observed with high speed cinematography. Sub-bituminous were observed to ignite homogeneously; however, low volatile bituminous coal and lignite undergo fragmentation prior to igntion. The observation was analyzed with previous work.

• 한국연소학회지
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• 제16권1호
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• pp.22-29
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• 2011

This paper focuses on the combustion characteristics of blended coals with bituminous and sub-bituminous coals under air and oxy-fuel combustion conditions. The effects of oxygen concentration and blending ratio on the combustion characteristics were experimentally investigated using a thermogravimetric analyser (TGA). Characteristic temperatures including ignition, burnout temperature and activation energy were determined from TG and DTG combustion profiles. As oxygen concentration increased and the presence of sub-bituminous coal, characteristic temperatures and activation energy decreased. The ignitability, reactivity and kinetics have all been greatly improved under oxy-fuel combustion conditions. Based on this, co-firing with bituminous and sub-bituminous coals under oxy-fuel combustion conditions may be suggested as an alternative method to the fuel flexibility and cost-effective power production with carbon capture and sequestration.

• 보존과학회지
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• 제29권4호
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• pp.345-354
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• 2013

태안군 마도 해역 해저에서 인양된 마도 1호선의 선체 내 외부에서 출토된 석탄의 지구화학적 및 광학적, 광물학적 특성을 분석하였다. 연구 결과, 석탄의 비중은 $1.28g/cm^3$로 약 10%의 광물질 함유 상태를 고려하면 순수한 석탄만의 비중은 $1.15g/cm^3$ 정도이며, 갈탄과 유연탄 사이의 범위 해당된다. X-선 회절분석 결과는 peak점의 $2{\theta}$는 $20^{\circ}{\sim}23^{\circ}$ 사이로 낮은 탄화정도의 석탄에 해당되었으며, 석탄구성물질 분류에서 비트리나이트 군이 93~94%, 엑시나이트 군이 5~6%, 인어티나이트군이 1% 이었다. 또한 석탄의 비트리나이트 평균반사율은 $R_{mean}$: 0.627로 고휘발분역청탄 C(high volatile bituminous C coal) 또는 아역청탄 A(sub-bituminous A coal)에 해당된다. 공업분석 결과 미국 광무국의 기준에 의하면 아역청탄 A(sub-bituminous A coal) 또는 고휘발분역청탄 C(high volatile bituminous C coal)에 해당되며, 원소 분석 결과 역청탄에 해당되는 점결탄으로 분류된다. 마도1호선 석탄과 국내 석탄을 비교 분석 결과 포항 인근 장기지역의 갈탄과 유사하였다.

• 한국대기환경학회지
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• 제26권2호
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• pp.151-160
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• 2010

Particles emitted from three coal-fired power plants burning bituminous and sub-bituminous coals were examined for PM and size fractions PM>2.5 and PM2.5. The ratio of PM2.5/PM was ranged from 10 to 62%, and PM emission increased with the amount of coal feed, which was 7.23~15.66 kg/h. The emission range of PM2.5 from three power plants was 1.24~4.48 kg/h (dry), which was function of the mixed rate of viscous sub-bituminous coal in feed. Of course such effect should be examined by further tests in details. Based on the consumed coal and thermal load, the emission factors averaged were shown as 59.03 g-PM/ton-coal, 14.79 g-PM2.5/ton-coal and 22.51 g-PM/MWh, 5.54 g-PM2.5/MWh, respectively.

• 한국연소학회지
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• 제15권4호
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• pp.65-73
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• 2010

In order to provide fundamental information for developing reaction model in the practical blended coal power plants, effects of particle size and blending ratio on combustion characteristics and thermal reaction in co-firing with bituminous and sub-bituminous coals were experimentally investigated using a TGA and a laboratory-scale burner. Characteristic parameters including ignition, burnout temperature and activation energy were determined from TG and DTG combustion profiles. Distributions of flame length and mean particle temperature were investigated from the visualization of flames in slit-burner system. As coal particle size decreased and volatile matter content increased, characteristic temperatures and activation energy decreased. The ignition/burnout characteristics and activation energy are linearly influenced by a variation in particle size and blending ratio. These results indicated that the control of the coal blending ratio can improve the combustion efficiency for sub-bituminous coals and the ignition characteristics for bituminous coals.

• 한국연소학회지
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• 제18권4호
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• pp.53-58
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• 2013

Lots of Coal power plants (about 30) using bituminous coals are being run in Korea. The use of high volatile low grade sub-bituminous coal is increasingly extended because of imbalance between the worldwide coal supply and demand. Mill-fire has been an important issue since the use of such sub-bituminous coal. In existing coal plants of Korea, shutdown of coal and air supplies could be only a way, and an alternative has not been found in suppressing the mill fire. The inside fowfield in the mills has a highly fuel-rich, low temperature, and high velocity and non-reactive such that it could be a nonreactive system essentially. Nevertheless, occasional fire-occurrence could be attributed to the existence of an ignition source. However it has not been so far investigated in detail. The current work has a focus on suppressing the mile fire via some parametric experimental study such as effects of temperature, residence time, ignition source, and inert gas mixing. The results show that an small amount of $CO_2$- or $N_2$-mixing with air is very effective in suppressing fire formation even at high temperatures or flying sparks. The results suggest that exhaust gas recirculation into the mill should be an alternative to suppress mill fire.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.27-46
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• 1999

Combustion test on two kinds of Indonesian sub-bituminous coals of single and blended with bituminous coal imported for power generation was carried out by using the test furnace at KEPRI. The main items of combustion test were temperature profiles of the inside furnace, the yield of unburned carbon, environmental pollution emissions, slagging/fouling tendency, and the comparison of heat loss of furnace. The test results showed that low sulfur and ash content characterized by the Indonesian coals were advantageous to environmental aspect, but high tendency of heat loss and slagging/fouling were disadvantageous to boiler operation. From the results, the necessity of proper coal blending to compensate these weak points was recommended.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.107-109
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• 2012

In Korean coal power plants, rising coal prices have recently led to the rapid utilization of low lank coals such as sub-bituminous coal with low calorific values and low ash fusion temperatures. Using these coals beyond the design range has resulted in important issues including slagging and fouling, which cause negative effects in boiler performances and unstable operations. The purpose of this study is to observe slagging and fouling characteristics resulted from burning various ranks of pulverized coals. We have tested 3 different coals: FLAME(bituminous), KCH(sub-bituminous) and MOOLARBEN(bituminous)coals in the pilot system $50kW_{th}$ scale. A stainless steel tube with preheated air inside was installed in the downstream in order to simulate water wall. Collected ash on the probe and the slag inside the furnace near burner were analyzed by SEM (scanning electron microscopy) to verify the formation degree, surface features and color changes of the pasty ash particles. Induced coupled plasma and energy dispersive X-ray spectroscopy were also performed to figure out the chemical characteristics of collected samples. As a result, KCH was observed that more slag was developed inside the walls of the furnace and on the probe than the other two kinds of coals, as shown in the calculate slagging and fouling indices as well.

• 플랜트 저널
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• 제18권1호
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• pp.55-61
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• 2022

본 연구에서는 역청탄으로 설계된 870MW급 유연탄 화력발전소를 대상으로 발전기 출력, 연소조건, 통풍조건을 일정하게 유지하면서 역청탄과 아역청탄을 혼합하여 연소함에 따른 슬래깅 발생 영향을 분석하였으며, 이에 따른 보일러 성능에 영향을 주지 않는 허용 가능한 혼탄 방안을 제시하였다. 아역청탄의 혼합 비율을 10%, 20%, 40%, 60%, 80% 등으로 조정하여 원소분석, 공업분석, 회융점 변화, 슬래깅 지수 등을 확인하였고, 적정 혼탄 조건은 아역청탄은 40% 이하로 혼탄하고, 회의 산성분 대비 염기성분 비율은 0.4이하 또는 1이상, 총 알칼리는 3.5이하, 융점 슬래깅 지수는 1,345℃ 이상, 원소분석 시 회함량은 13% 이하, 공업분석 시 회함량은 15% 이하, 초기용융점은 최소 1,200℃ 이상이어야 바람직하다고 판단된다.