• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.28-36
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• 1996

The objects of this study were to investigate emissions of air pollutant the particles as well as the combustibility of the low grade domestic anthracite coal and imported high-calorific bituminous coal in the fluidized bed coal combustor. The production of air pollution from anthracite-bituminous coal blend combustion in a fluidized bed coal combustor was evaluated. The effects of air velocity and anthracite fraction on the reaching time of steady state condition was also evaluated. We used coal samples the domestic low grade anthracite coal with heating value of 2,010 kcal/kg and the imported high grade bituminous coal with heating value of 6,520 kcal/kg. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 0.3 m/s which was the fastest. It has been found that $O_2$ and $CO_2$ concentration were reached steady state at about 100 minute. As the height of fluidized bed becomes higher, the concentration s of $SO_2$ and $NO_x$ mainly increased. The concentration of freeboard was the highest and emission concentration was diminished. Also, as anthracite fraction increased, the emission of $SO_x$ concentration was increased. But, it has been found that the variation of $NO_x$ concentration with anthracite fraction was negligible and the difference of emission concentration according to air flow rates was negligible, too. It has been found that $O_2$ concentration decreased and $CO_2$ concentration increased as the height of fluidized bed increased. As anthracite fraction increased, the mass of elutriation particles increased, and $CO_2$ concentration decreased. Also, as air velocity increased, $O_2$ concentration decreased and $CO_2$ concentration increased. Regardless-of anthracite fraction and flow rate, the combustible weight percentage in elutriation particles were high in the case of fine particles.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.501-509
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• 2016

The economic feasibility of a commercial indirect liquefaction process with the co-gasification process of petroleum coke which has been recognized as hazardous waste because of high sulfur content and bituminous coal and sub-bituminous coal mixtures was assessed. The 2,000 ton/day scale indirect liquefaction process including co-gasification, clean up, Fischer-Tropsch conversion and so on was assumed and used to analyze economical efficiencies with various conditions. Financial data from previous studies were modified and used and economical sensitivities with various mixture ratios were evaluated in this study. As a result, economic values of petroleum coke were superior than those of coals because of increasing sulfur sale. Also, mixtures with petroleum coke and bituminous coal was more favorable that those with petroleum coke and sub-bituminous coal due to lower moisture content. In case of sub-bituminous coal, the mixture ratio with petroleum coke had to be over 40wt% for the IRR of mixture to surpass 10%.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.84-87
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• 2008

The sulfur oxides is one of important materials to come about air pollution at thermal plant consuming fossil fuel. The several flue gas desulfurization equipments are installed and operated to decrease sulfur oxides. The flue gas desulfurization of our thermal plant is designed for optimizing flue gas desulfurization technical development and research by Korea Electric Power Research Institute. We operate this desulfurization equipment. Now, our country imports nearly 97 percentage of the energy source and competes with the world for the energy because of the rise of raw materials cost. The fuel cost decrease of power plants is the most important factor of the operation. The fuel used in the experiment is the domestic anthracite from Kangwon Taeback and the bituminous coal from Russia,Taldinsky Mine. This Study is experimental investigations of desulfurization characteristics for domestic anthracite power plant by increasing bituminous coal. We surveyed possible parameters and conducted the performance about desulfurization equipment in Y.D thermal power plant.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.93-97
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• 2015

The combustion tests for Korean anthracite-bituminous coal blend were carried out in the 200 MW utility boiler. The burning characteristics of the blend were studied with a thermogravimetric analyzer (TGA). From the observation of TGA burning profiles, it was found that the presence of bituminous coal in the blend appeared to enhance the reactivity of anthracite in the higher temperature region, indicating certain interactions between the two coals. The plant test showed the boiler operation was reasonably stable with somewhat poor combustion efficiency, and some modification of the combustion environment in the furnace is necessitate for the further stable plant operation.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.207-214
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• 2014

With the depletion of high grade coal, it is indispensable to be used co-combustion of low rank coal with bituminous coal in pulverized coal-fired power plants. This study describes the detailed measurements of combustion characteristics of bituminous and subbituminous coal in a 0.7MWth pilot-scale test facility. This experimental works include the measurement of gas temperature, gas concentrations along with the reactor axial and radial distance at the condition of excess air ratio of 1.2. The solid sampling was carried out and analyzed with the combustion of bituminous coal. The main reaction zone of coal flame in a reactor was formed about 1 m from the swirl burner, and at downstream, the fully developed temperature and species distribution was observed. The sampled particles of bituminous coal in a reactor revealed the complete carbon burn-out was achieved just after an main combustion zone.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.39-44
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• 1999

발전용 연료로 사용하는 석탄은 취급의 어려움과 가스 및 석유에 비해 품질이 낮은 단점이 있으나, 매장량이 풍부하고 가격이 저렴하여 발전용 연료로의 사용은 더욱 증대될 전망이다. 이에 따라 석탄의 안정적 수급 측면에서 구입원의 다양화가 예상되고 있으나, 현재 발전용 연료의 연소특성 평가는 주로 실험실적 기초 시험에 의존함에 따라 정확한 평가가 곤란한 실정이므로 시험연소로를 이용하여 각종 연소특성을 비교 평가하여 탄종별 최적 연소조건 규명과 적정 흔탄비에 대한 Data Base를 구축하고자 한다.(중략)

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.189-195
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• 2011

Korea-specific GHG emissions should be estimated correctly in order to ensure effective measurement of climate change variables. The use of country-specific data that reflects fuel and technology characteristics is needed for accurate GHG emissions estimation. Oxidation factors are used to convert existing data into equivalent GHG emissions, and changes in these oxidation factors are directly related to changes in emissions. As such, the oxidation factor is one of the most important variables in using country-specific data to determine GHG emissions. In this study, the oxidation factor of bituminous coal in large scale boilers was estimated using 4,527 data points sampled from eight large-scale boilers that had been using bituminous coal for two years. The average oxidation factor was determined to be 0.997, which is lower than the oxidation factor of 1 that is recommended by the IPCC G/L for large scale boilers when estimating national GHG emissions. However, an oxidation factor less than 1 is assumed for fluidized bed boilers, internal combustion engines, and other small-scale boilers. Accordingly, studies on oxidation factor estimation should be continued to allow for accurate estimation of GHG emissions.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.7-16
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• 1998

Numerical computations were performed for the gasification of five different coals such as Lewis-Stockton bituminous, Utah bituminous. Illinois #6 bituminous, Usibelli sub-bituminous and Beulah-Zap lignite, to assess the effect of variation in oxygen to coal ratio and steam to coal ratio on reactive flow fields within an axisymmetric, entrained-flow gasifier. The concentrations of major products, CO and $H_2$, were calculated with varying oxygen to coal ratio(0.7~1.4) and steam to coal ratio. To verify the validity of predictions, the predicted and the measured values of CO and $H_2$ concentrations at the exit of the gasifier were compared for Roto coal. Reasonable agreement was obtained between the predicted and measured values. Predictions showed that the (CO+H_2$) concentration increased gradually to its maximum value with increasing oxygen-coal ratio, and CO concentration decreased, but $H_2$ concentration increased to some extent with increasing steam-coal ratio. When the oxygen-coal ratio was between 1.0 and 1.2, and the steam-coal ratio was between 0.3 and 0.4, high values of the cold-gas efficiency were obtained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.257-263
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• 2008

We have examined explosion characteristics of bituminous coal dusts in cement manufacturing process. In order to find the thermal properties, we investigated weight loss and ignition temperature of coal materials using TGA and DSC. Also specific surface area of dust was investigated. Dust explosion experiments with Hartman's dust explosion apparatus have been conducted by varying concentration and size of coal dust for explosion probability and lower limit explosion concentration. According to the results for thermal properties, there is a little change by dust size. However, the specific surface area of dust is increased by decreasing dust size. The explosion test results show that small size and increasing concentration of dusts make dust explosion easier. And we find that the lower limit explosion concentration of bituminous coal is $0.3mg/cm^3$ and the probability is 100% on $0.9mg/cm^3$ in 170/200 mesh used in cement manufacturing process.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.127-142
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• 2017

After individual consumption tax on bituminous coal has been imposed by Korean government after 2014 Jul, we analyse the influence of tax and conclude that the consumption of high calorie coal has been increased and that of low/middle calorie coal has been decreased. And also, the average calorie of coal consumption has been increased and the more fuel cost happens on account of the average calorie increase. Those effects have been caused by the current tax imposition system which does not reflect the bituminous coal trait. The motivation of oversea resource development and the effort of coal blending skill have been decreased because of the current tax policy. We suggest 2 ways of the tax policy improvement system[1. tax imposition system in proportion to 5,000kcal/kg, 2. 15 stages(1 stage : 200kcal/kg) segmentation tax imposition system equal to the tax/(5,000kcal/kg)] to increase the current tax amount, to prevent the coal consumption distortion and to remove the further fuel cost.