• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.209-212
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• 2012

This study was performed to analyze coal flames and measure tar and soot yields and structures of chars for two coals depending on the volatile content by the LFR(Laminar Flow Reactor) which can be applied to a variety of coal researches. The results show that volatile contents and oxygen concentration have significant influence on length and width of the soot cloud and it also indicate that the length and width of the cloud in condition of combustion decrease than those of pyrolysis atmosphere. Until the sampling height reach at 50 mm, the tar and soot yields of Berau (Sub-bituminous) coal contained relatively lots of volatile matters are less than those of Glencore A.P. (Bituminous) coal. On the other hand, tar and soot yields of Berau coal are higher than those of Glencore A.P. coal by reacted residual volatile matter. In addition, the images of samples obtained from the particle separation system of the sampling probe support for above results with the yields, and the pore development of char surface by devolatilization.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.279-284
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• 2016

Assessing the handling properties of coal becomes a major issue for the operation of a fuel supply system in power plants, due to the increased types of coal imported into Korea. In this study, the cohesion strengths of 13 bituminous and sub-bituminous coals from different countries were tested by measuring the amount of force that leads to a failure of consolidated particles. The particle size was in the range of 0.1-2.8 mm, which represents the coarse particles before pulverization. While the cohesion strength was proportional to the compression force in the tested range, the effects of the surface moisture content and the weight fraction of fines were crucial for cohesive coals. At fixed conditions of surface moisture and particle size, large variations were found in the cohesion propensity between coals. For coals of 0.1-0.5 mm with the moisture added close to the critical value, cohesive coals had the density over $900kg/m^3$ after consolidation. The cohesion propensity was not correlated with the basic properties of coals with sufficient statistical significance.

• 대한기계학회논문집B
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• 제33권8호
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• pp.613-621
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• 2009

Coal is the energy resource which is important with the new remarking energy resource. Coal combustion produces more NOx per unit of energy than any other major combustion technology. Pollutant emission associated with coal combustion will have a huge impact on the environment. Coal conversion has three processes which are drying, coal devolatilization and char oxidation. Coal devolatilization process is important because it has been shown that HCN which is converted from volatile N contributes 60 to 80% of the total NOx produced. This paper addresses mass release behavior of char, tar, gas and HCN in an experiment of Laminar Flow Reactor with two coals such as Roto middle coal (Sub-bituminous) and Anglo coal (Bituminous). The experiment is compared with the data predicted by CPD model for mass release of HCN about Roto south, Indominco, Weris creek and China orch coals. The results show that HCN increases as a function of decreasing the ratio of fixed carbon(FC)/ volatile matter(VM of the coals contain.)

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.197-204
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• 2021

Pressure swing adsorption is a purification process which can get pure hydrogen. The purification process is composed of four process: compression, adsorption, desorption and discharge. In this study the adsorption process was simulated by using the Fluent and validated with experimental results. A gas used in experiment is composed of H₂, CO₂, CH₄, and CO. Adsorption process conducted under 313 kelvin and 3 bar and bituminous-coal-based (BPL) activated carbon was used as the adsorbent. Langmuir model was applied to explain the gas adsorption. And diffusion of all the gases was controlled by micro-pore resistances. The result shows that, the most adsorbed gas was carbon dioxide, followed by methane and carbon monoxide. And carbon monoxide took the least amount of time to reach the maximum adsorption amount. The molar fraction of the off-gas became the same as the molar fraction of the gas supplied from the inlet after adsorption reached the equilibrium.

• 에너지공학
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• 제18권4호
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• pp.239-246
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• 2009

본 논문에서는 주위 가스 온도와 체류시간에 따른 아 역청탄 촤 입자의 연소 특성에 관한 기본적인 연구를 진행하였다. 실험용 장비로써 노 내 온도 범위가 $900^{\circ}C$에서 $1400^{\circ}C$까지 조절이 가능한 DTF(drop tube furnace)를 설치하였고, 온도가 보정된 two color pyrometer를 DTF의상부에 장착하여 촤가 산화할 때의 입자 온도를 측정할 수 있게 하였다. 촤 산화 시 반응한 총 질량을 구하기 위해 열중량 분석기를 사용하였으며, 회분 추적법을 통해분석하였다. 이를 통해대기압 조건에서 촤가산화 할때질량 및 면적 반응성, 반응속도 상수들을 결정하였다.

• Asian Journal of Atmospheric Environment
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• 제7권1호
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• pp.48-55
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• 2013

The purpose of this study was to develop a $CO_2$ emission factor for refuse plastic fuel (RPF) combustion facilities, and calculate the $CO_2$ emissions from these facilities. The $CO_2$ reduction from using these facilities was analyzed by comparing $CO_2$ emission to facilities using fossil fuels. The average $CO_2$ emission factor from RPF combustion facilities was 59.7 Mg $CO_2$/TJ. In addition, fossil fuel and RPF use were compared using net calorific value (NCV). Domestic RPF consumption in 2011 was 240,000 Mg/yr, which was compared to fossil fuels using NCV. B-C oil use, which has the same NCV, was equal to RPF use. In contrast, bituminous and anthracite were estimated at 369,231 Mg/yr and 355,556 Mg/yr, respectively. In addition, the reduction in $CO_2$ emissions due to the alternative fuel was analyzed. $CO_2$ emissions were reduced by more than 350 Mg $CO_2$/yr compared to bituminous and anthracite. We confirmed that using RPF, an alternative fuel, can reduce $CO_2$ emissions.

• 대한기계학회논문집B
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• 제23권11호
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• pp.1464-1472
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• 1999

Design and operation of $1MW_{th}$ pulverized coal combustion testing facility are described. Also the influence of air staging on NOx emission and burnout of coal flames was investigated in this facility. The test facility consisted of coal feeding system, firing system and flue gas treatment system. A top-fired externally air staging burner was adopted in order to avoid influence of gravity on the coal particles and for easy maintenance. Distribution of temperature and chemical species concentration of coal flames could be measured in vertical pass of furnace. Main fuel was pulverized (83.4% less than $80{\mu}m$) Australian high bituminous coal. From variety of test conditions, overall excess air ratio was selected at 1.2(20% excess air). Tho study showed that increasing the staged air resulted in lower NOx omission, and it was suggested to be more than 40% of the total combustion air for the substantial NOx reduction. Sufficient burnout was not achievable when NOx emission was less than 500ppm. Also, the amount of core air did not influence tho NOx reduction.

• 공업화학
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• 제33권1호
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• pp.28-37
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• 2022

석탄화력발전소들은 여전히 저급 석탄인 lignite와 bituminous coal을 이용한 발전이 이루어지고 있지만, 이는 CO₂와 같은 GHG를 배출하는 문제를 유발하고 고갈의 위험성이 있어 이를 대체할 에너지원이 필요하다. 이를 해결하기 위해 바이오매스를 이용한 hydrochar 생산이 주목받고 있다. 본 연구에서는 고품질 hydrochar의 생산을 위해 용매열법을 열수탄화에 적용하여 에탄올 수용액을 기반으로 진행되었다. 본 실험은 다양한 조건에 따른 영향을 파악하기 위해 케나프를 이용해 고액비(1:4, 1:8, 1:2), 반응온도(150~300 ℃)와 체류시간(15~120분)을 다양하게 변화하며 진행되었다. 또한 생산된 hydrochar의 특성을 파악하기 위해 EA, FT-IR. TGA와 SEM을 이용해 분석을 진행하였다. Hydrochar의 탄소 함량은 kenaf에 비해 48.11% 증가하였고, 휘발성 물질은 39.34%가 감소하였다. 추가적으로 반응온도에 따라 연료적 특성이 강화되는 것 또한 확인하였다. 본 연구에서 나타난 결과는 kenaf가 열수탄화와 용매열법을 통해 연료 대체재로써 변화하는 것을 확인하였으며, 이는 석탄의 새로운 대체재가 될 수 있는 가능성을 보였다.

• 에너지공학
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• 제21권1호
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• pp.68-74
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• 2012

국내 석탄화력발전소의 아역청탄과 역청탄의 혼소는 일반화되어 있으며 아역청탄의 비율이 무게 기준으로 50%가 넘는 경우도 있다. 저급탄인 아역청탄의 혼소 비율이 높아짐에 따라 연소 부산물인 비회에서 미연물질이 다량 발생하고 있으며 이는 콘크리트 혼화제로서의 비회 재활용을 가로막는 중요한 인자로 작용하고 있다. 본 연구에서는 아역청탄 혼소율이 높은 국내 500MW 표준 석탄화력발전소에서 미연물질이 포함된 비회를 입수하여 이에 대한 분석을 수행하였다. 이러한 미연물질은 석탄의 열분해 생성물인 검댕(soot)인 것으로 나타났으며 실제 석탄화력발전소에서 사용하고 있는 석탄과 혼탄의 성상 데이터와 CPD모델을 사용하여 혼탄별 검댕(soot)의 발생가능성을 분석하였다.

• Advances in Energy Research
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• 제4권3호
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• pp.203-211
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• 2016

A good understanding of the chemical composition and structural characteristics of a carbonaceous material is essential in conversion processes. Understanding how the composition and structural changes influence the burning behaviour of coal is important when assessing a coal's potential for utilization. To explore the potentials of a typical Nigerian coal, both conventional and advanced analytical techniques such as proximate analysis, ultimate analysis, calorific value, surface area analyser, SEM, FTIR, XRD and SAXS were employed. The results obtained from these characterizations agree favourable well with a typical South African coal that is of enormous contribution to the gross domestic product (GDP) of the nation economy.