• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.43-47
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• 2003

Coke oven is used in an iron-making process for producing coke through devolatilization of the coking coal. An unsteady 2-dimensional model of solid bed is proposed to simulate a coke oven. The model contains governing equations with partial differential equation forms for the solid phase and the gas phase. Drying and devolatilization of coking coal, heat transfer, and generation of internal pores in the coking coal are also reflected to the source terms. Simulation results show a reasonable trend compared with the physical data.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.389-392
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• 2003

Coalfields in Korea have been grouped into thirteen based on mainly geographycal and geological structure, ten out of which have been developed. To classify the phisico-chemical characteristics of mine drainage from each coalfield and, if possible, to clarify the intrinsic reasons of them. Sampling of waters from 59 mines in eight coalfields has been carried out. Higher pH of drainage water from the mines of the Cungchung coalfield belong to the Beading system, Mesozoic era than those belong to the Pyungan system, Proterozoic era is due to the low content of sulfides of neighboring strata. The drainage from coal beds overlying limestone bed mostly show high pH. Waters from the Gangrung and Samchuck coalfields coal beds are located within black shale formation which contains a lot of sulfides showed mostly very high metal and S $O_{4}$$^{2-}$ concentrations.

• 한국안전학회지
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• 제12권2호
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• pp.111-118
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• 1997

Granulation procedure was carried out in a 0.109m I. D., 1.8m height fluidized bed coal combustor of the multi-sized particles. The domestic anthracite with heating value 3240kcal/kg was used. Granulation of fine coal particles and fluidizing characteristics were investigated by the pressure fluctuation properties such as mean pressure, standard deviation of pressure fluctuation and power spectrum distribution. Defluidization state and granulation mechanism were also studied by the various analysis. It was found that the conversion efficiency in the elutriated stream was increased by the coalescence of fine coal particles. Defluidization and pressure fluctuation properties were interrelated and this result was indication of the capabilities of pressure fluctuation properties analysis in the diagnostics of fluidizing state.

• 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.

• 공업화학
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• 제8권3호
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• pp.517-523
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• 1997

본 연구는 유동층연소로에서 유,무연탄 혼합연소시 대기오염물질 발생과 연소효율에 관하여 실험하였으며, 실험결과는 다음과 같다. 유동층연소로 높이가 증가할수록 이산화황과 질소산화물의 농도는 증가하는 것으로 나타났으며, 무연탄 혼합비가 증가할수록 이산화황의 농도는 증가하였으나 질소산화물농도는 큰 변화가 없었다. 무연탄 혼합비가 증가할수록 비산유출율도 증가하였고 주입 가연성분에 대한 유출 가연성분비도 증가하였다. 또한, 무연탄 혼합비에 관계없이 비산유출입자의 평균입경에 따른 미연분 함량은 미세입자에서 대체로 높게 나타났다. 한편, 연소효율은 층온도 $850^{\circ}C$, 과잉공기 20% 이상에서 큰 차이를 보이지 않았으므로 유속 0.3m/s, 층온도 $850^{\circ}C$, 과잉공기비 20%의 조건으로 혼합연소시키는 것이 적절한 것으로 나타났다.

• 대한화학회지
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• 제7권4호
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• pp.288-292
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• 1963

The rates of reaction of various Korean anthracites with carbon dioxide were measured at temperatures ranging from $850^{\circ}C$ to $1100^{\circ}C$ with coal -6, +8 sieve size and the residence time of reactant gas in the fixed coal bed 14.0 to 15.0 seconds. The primary variables studied were the coal sources and temperature. The reactivity was considerably varies with the coal sources and the general trends show that the reactivity sharply increases with increasing reaction temperature except the Yongwol coal where the increase is not so sharp, which is considered to be due to high reactivity and high-pore structure of the coal. It was also found that a straight line was produced when a logarithm of the rate constant is plotted against the reciprocal of the absolute temperature up to 1000^${\circ}C$, but above that temperature it deviates from linearity. The information obtained will be of value in the design of the coal gasifier using Korean anthracites.

• 한국입자에어로졸학회지
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• 제9권4호
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• pp.239-246
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• 2013

The purpose of this study is to determine the feasibility of dry-type desulfurization process for actual application to coal-fired power plant. We used actual exhaust gas from Facility Y, Plant #2 to fabricate a demo-scale testing device to attempt to improve the efficiency of desulfurization. A spout-bed circulating dry scrubber convergence system connecting turbo reactor with bag filter was devised, then analyzed for performance characteristics of $SO_2$ removal for Ca/S mole ratio, superficial gas velocity, and ammonia injection, and for secondary reaction characteristics of the non-reactive sorbent at the bag filter. As a result, the installation of spout-bed circulating dry scrubber convergence system showed better economy and efficiency for removing sulfur than the existing wet/semidry-type desulfurization process. In addition, the best efficiency for desulfurization occurred when connected to the bag filter, with differential pressure maintained at 150 $mmH_2O$.

• 대한기계학회논문집B
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• 제23권8호
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• pp.1022-1030
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• 1999

A numerical study was carried out to analyze the effect of flow distribution of stirred part and plug flow part on combustion efficiency at the coal gasification process in an entrained bed coal reactor. The model of computation was based on gas phase eulerian balance equations of mass and momentum. The solid phase was described by lagrangian equations of motion. The $k-{\varepsilon}$ model was used to calculate the turbulence flow and eddy dissipation model was used to describe the gas phase reaction rate. The radiation was solved using a Monte-Carlo method. One-step parallel two reaction model was employed for the devolatilization process of a high volatile bituminous Kideco coal. The computations agreed well with the experiments, but the flame front was closer to the burner than the measured one. The flow distribution of a stirred part and a plug flow part in a reactor was a function of the magnitude of recirculation zone resulted from the swirl. The combustion efficiency was enhanced with decreasing stirred part and the maximum value was found around S=1.2, having the minimum stirred part. The combustion efficiency resulted from not only the flow distribution but also the particle residence time through the hot reaction zone of the stirred part, in particular for the weak swirl without IRZ(internal recirculation zone) and the long lifted flame.

• 청정기술
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• 제19권4호
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• pp.464-468
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• 2013

본 연구에서는 석탄 종류, 저등급석탄으로부터 첨가제의 종류, 입도분포 및 건조 방법에 따른 석탄-물 혼합연료(coal water fuel, CWF)의 고체함유량을 높이고자 하였다. 건조 방법에는 열풍 건조 방법(flash drying, FD), 유동층 건조 방법(fluidized bed, FB), 유중 건조 방법(oil deposit stabilized, ODS)을 사용하였다. 석탄 종류에 의해서 고체함유량 차이는 최대 20% 이상 보였다. 또한, CWF을 제조할 때 넣어주는 첨가제의 종류를 다르게 하여 실험한 결과 첨가제에 의해서 5%까지 효율을 더 높일 수 있었다. 석탄의 입도분포는 $75{\mu}m$ 이하의 미분탄이 80% 함유되어야 CWF의 성능이 향상되는 것을 관찰하였다. 3가지 건조 방법을 활용하여 CWF를 제조해본 결과, 안정화시킨 유중 건조 석탄이 원탄에 비하여 12% 정도 더 높은 고체함유량을 갖는 CWF를 제조할 수 있는 것을 알 수 있었다.

• Korean Chemical Engineering Research
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• 제47권6호
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• pp.710-714
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• 2009

본 연구에서는 석탄가스의 환원도와 석탄가스에 함유된 $H_2O/H_2S$ 농도변화에 따른 세 가지 종류의 아연계 탈황제의 반응성능을 회분식 유동층반응기에서 분석하였다. 가스화에서 생성되는 가스의 조성은 환원도가 각각 다른 KRW(Kellogg-Rust-Westinghouse) 공기이용 가스 조성, Shell 산소이용 가스 조성, 고등기술연구원의 가스 조성을 기준으로 모사가스를 이용하여 입구의 $H_2O$와 $H_2S$ 농도를 변화시켜 실험을 수행하였다. $H_2O$의 농도는 5부터 30%까지 $H_2S$의 농도는 0.5에서 2%로 변화시켜 탈황성능을 분석하였다. 실험 결과 $H_2O$의 농도가 증가할수록 탈황성능이 감소하고 입구의 $H_2S$ 농도가 증가할수록 탈황반응기 후단의 $H_2S$ 농도 역시 증가하였다. 모든 조건에서 환원도에 따른 탈황성능 변화는 없었으며 탈황성능은 최저 99.5%로 건식탈황제를 이용하여 99% 이상의 $H_2S$ 제거 성능을 보이는 것을 확인하였다.