• 한국연초학회지
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• 제20권1호
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• pp.5-12
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• 1998

Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

• 한국연초학회지
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• 제19권2호
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• pp.92-101
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• 1997

This study was conducted to investigate the effect of fly ash on the yield and quality and to determine the optimum application amount of fly ash for tobacco(Nicotiana tabacum L). Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 20, 40, 60 MT/ha. Dry weights of tobacco at middle and topping growth stage were increased with application of fly ash, showing the highest dry weight at 40 MT/ha in both kinds of fly ash. It was showed that the bituminous coal had a little more effective for yield than that of anthracite. Comparing with the control, yields of tobacco applied with fly ash were significantly increased about 17.7% and 17.1% by the application of bituminous coal and anthracite, respectively. Quality of flue-cured leaves was better by application of fly ash than that of the control. The quality index was given the highest at 40 MT/ha for bituminous coal increasing by 24.6% and at 60 MT/ha fur anthracite increasing by 13.4% compared with the control. The economical efficiency considered of the yield and quality of tobacco was the highest at 40 MT/ha of bituminous. Soil pH, contents of available P2O5, organic matter, exchangeable Ca2+ and Mg2+ of soil during the growing season were increased by application of fly ash, showing more effectiveness in bituminous than that in anthracite. By the application of fly ash, the nutrients availability and the acidity of soil were reformed and they caused significantly the increase of growths yield, and quality of tobacco. By the application of lime reforming soil acidity, growth response, yields and quality of tobacco were not increased compared to the control, although the effect of reforming soil pH was remarkable.

• 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.

• 환경영향평가
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• 제8권4호
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• pp.25-35
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• 1999

Fly ash, by-product from coal fired power station, has long been regarded as a potential contamination source for heavy metals and inorganics due to their enriched concentrations and associations with particle surface. Feed coal and fly ash samples were collected from two power stations; Yongdong deliang with domestic anthracite coals and Boryong with imported bituminous coals. The coal and fly ash samples were analyzed for chemical composition and mineral components, using XRF and XRD. Batch leaching experiments were conducted by agitating samples with deionised water for 24 hours. Anthracite coals are generally higher in Al and Si contents than bituminous coals. This is due to the higher ash contents of the anthracite coal than bituminous coal. The chemistry of the two fly ash samples shows broadly similar compositions each other, except for the characteristically high contents of Cr in anthracite coal fly ash. Leaching experiments revealed that concentrations of metals gradually decreased with leachings in general. However, measurable amounts of metals were present in the effluent from weathered ash and the samples subjected to the leaching procedure. These metals are likely to indicate that the metals in fly ash were incorporated into glass fraction as well as associated with particle surface of samples. Dissolution of aluminosilicate glass would control releasing heavy metals from fly ash as weathering progresses during landfill with implication of possible groundwater contamination through fly ash landfill.

• 한국연소학회지
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• 제10권3호
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• pp.1-9
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• 2005

The characteristics of co-combustion of Korean anthracite and bituminous coal was determined in a TGA and a lab-scale CFB reactor. The combustion reactivity of Korean anthracite (E = 51.2 kcal/mol) was much lower than that of bituminous coal (E = 14.5 kcal/mol). As the addition amount of the bituminous coal into the anthracite was increased, the reactivity of the anthracite was found to be improved. The effluent rate of the emission gases from the CFB reactor was not changed appreciably when each coal burned. As the bituminous coal was added, however, the effluent rate of the emissions was increased. The unburned carbon in fly ash from the CFB reactor was decreased with increasing the ratio of bituminous coal in co-combustion. But as the ratio of the bituminous coal was larger than 40 %, the combustion reactivity was not increased any more.

• 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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• 제6권2호
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• pp.70-77
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• 2010

This study investigated the characteristics of co-combustion of mixed anthracite (domestic and Vietnam) and bituminous coal (Sonoma, Australia) at circulating fluidized bed boiler in Donghae thermal power plant when mixing ratio of bituminous coal is variable. Co-combustion of bituminous coal contributes to improvement in general combustion characteristics such as moderately retaining temperature of furnace and recycle loop, reducing unburned carbon powder, and reducing discharge concentration of NOx and limestone supply owing to improvement in anthracite combustibility as the mixing ratio was increased. However, bed materials were needed to be added externally when the mixing ratio exceeded 40% because of reduction in generating bed materials based on reduction in ash production. When co-combustion was conducted in the section of 40 to 60% in the mixing ratio while the supplied particles of bituminous coal was increased from 6 mm to 10 mm, continuous operation was shown to be possible with upper differential pressure of 100 mmH2O (0.98 kPa) and more without addition of bed materials for the co-combustion of mixed anthracite and bituminous coal (to 50% or less of the ratio) and that of domestic coal and bituminous coal (to 60% of the ratio).

• 에너지공학
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• 제23권2호
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• pp.42-48
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• 2014

미분탄의 연소 또는 열분해 과정으로부터 발생하는 tar-soot는 복사 열전달 및 질소산화물의 추가적인 발생 원인이라는 관점에서 의미 있게 다루어지고 있다. 최근 저열량탄이 증가함에 따라 시멘트의 원료로 재활용되던 석탄회에서 다량의 미연분과 tar-soot가 포함되어 오히려 다시 반입되는 사례가 빈번해지고 있다. 따라서 본 연구에서는 저열량탄 사용 확대에 따른 혼탄연소 조건에서 tar-soot의 배출특성을 살펴보기 위해 반응기로써 LFR(Laminar Flow Reactor)을 적용하였으며, 연료로는 현재 국내발전소에서 사용 중인 역청탄 2종(MOUNTAIN, MACARHTUR)과 아역청탄(KPU)을 이용하여 단탄별 tar-soot 배출특성과 혼소비에 따른 배출특성을 화염의 구조 변화와 함께 측정하였다. 휘발분이 많은 아역청탄의 soot cloud 길이는 역청탄에 비해 길었지만 전체적인 화염 길이는 짧아졌다. 단탄별 실험결과에서는 역청탄의 tar-soot 발생량이 아역청탄의 발생률보다 높았으며 역청탄 중 휘발분 함량이 많은 MOUNTAIN탄이 상대적으로 휘발분 함량이 적은 MACARHTUR탄의 tar-soot 발생률보다 높았다. 혼소시에는 단탄의 연소특성과는 다른 새로운 특성을 나타내었으며 저열량탄과 혼소되는 역 청탄의 종에 따라 tar-soot 발생량이 지배되는 것을 확인하였으나 혼소비에 따른 평균적 특성이 아닌 완전히 차별되는 배출특성을 나타냄에 따라 석탄의 등급에 따라 최적의 혼소비를 찾아서 연소시키는 것이 tar-soot 발생량을 줄일 수 있는 방법임을 의미한다.

• 자원리싸이클링
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• 제5권3호
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• pp.44-49
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• 1996

국내 석탄발전소에서 배출되고 있는 비산회의 재활용에 가장 큰 문제점은 비산화에 혼입되어 있는 미연탄소분이다. 본 연구는 기존 포말부유선광법으로 유연탄비산회의 미연탄소분을 제거할 때 기포제종류 및 첨가량의 영향, 포집제 첨가량의 영향을 실험하고, 여기에서 수율, 회수율, 미연분제거율, 공정효율을 구하였다. 또한 비산회정제 전후의 화학적 성분을 분석하여 성분변화를 확인하였다. 실험결과는 유연탄 비산회 중의 미연탄소분을 92.4%까지 제거할 수 있었으며, 그 결과 비산회의 순도를 99.4%까지 높일 수 있었다.

• 에너지공학
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• 제21권4호
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• pp.427-434
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• 2012

국내 500MW 석탄화력발전소에서 사용중인 역청탄 (앵글로탄)과 아역청탄 (타니토탄)을 입수하여 석탄회의 기본적인 연료 및 연소특성을 살펴보았다. 또한, 열기계분석기를 이용하여 석탄 회에 대한 고온 용융특성을 평가하고 최근 새롭게 제시된 BHEL 슬래깅 지수를 구하였다. 아역청탄인 타니토탄 회는 $1,200{\sim}1,250^{\circ}C$에서 대부분의 용융이 발생하고 있으나 역청탄인 앵글로탄 회는 상대적으로 높은 온도인 $1,550^{\circ}C$ 부근에서 급격한 용융이 발생하였다. 석탄 회의 용융특성과 석탄중의 회 함량을 고려한 BHEL 지수는 두 탄종 모두 슬래깅성이 높은 것으로 나타났다. 반면, 기존의 슬래깅 지수들은 서로 다른 슬래깅성을 보여주었다.