• 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%.

• 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 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.

• 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.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.513-520
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• 2016

Korea's energy consumption has been constantly increasing. Final energy consumption was increased by an annual average of 2.9% compared to 2010. The consumption of all energy sources except for its oil was increased during the same time. While electric demand has increased coal consumption increased rapidly. Therefore, calorfic value and carbon emission factor development can improve the quality of Korea's greenhouse gas inventory. Calorific value is the amount of heat generated while burning coal. Caloric value is one of the most important factors in the development of carbon emission factors. Calorific value is used as the basis for the analysis of the various energy statistics. This study has calculated the other bituminous coal and coking coal's calorfic value by the data received from domestic coal-fired power plants and steel manufacturer. Calorofic value's trend analysis period is the year of 2010~2014. Through analyzing the carbon content it was calculated the carbon emission factor. The bituminous coal and coking coal's uncertainty analysis was performed using a Monte Carlo simulation.

• 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 Astronomy and Space Sciences
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• v.15 no.1
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• pp.163-174
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• 1998

To study the origin of organic matter in meteorite, terrestrial rocks which contain or-ganic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Muchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molec-ular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of ${\delta}^{13}C,-20.1%_0~-54.4%_0$ compared to bituminous coal, $-25.2%_0~34.3%_0$. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of ${\delta}^13C\;from\;-13%_0\;to\;+30%_0$. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

• Journal of Energy Engineering
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• v.2 no.3
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• pp.285-292
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• 1993

A cylindrical-shape, horizontal furnace was used to investigate the effect of particle size on the pulverized coal combustion behavior. Three differently-sized fractions (5, 30, and 44 microns in average diameter) of high-volatile bituminous coal, were burned in the test furnace. Ignition characteristics of pulverized coal flame were determined through the amount of methane in the carrier gas for the self-sustaining flame. Easiest ignition occurred with the immediately-sized coal particles. Ignition of coal jet flame appeared to occur through a gas-phase homogeneous process for particles larger than 30 microns. Below this limiting size, heterogeneous process probably dominated ignition of coal flame. Oxygen concentration of combustion air was varied up to 50%, to determine the oxygen-enrichment effect on the coal ignition behavior. Oxygen enrichment of primary air assisted ignition behavior of pulverized coal flame. However, enrichment of secondary air didn't produce any effect on the ignition behavior.

• Journal of Environmental Health Sciences
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• v.36 no.2
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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.

• Journal of Energy Engineering
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• v.17 no.3
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• pp.153-160
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• 2008

The combustion behaviors of the blends of Korean anthracite, bituminous coal and their blends were studied with a thermogravimetric analyzer. Concerning the burning profiles of the anthracite-bituminous coal blends in TGA, it has been observed the independent burning of two coals without any interaction between two coals. With the blends of 50% anthracite with 50% bituminous coal in weight basis, the combustion tests in a utility boiler have been carried out for the analysis of the combustion and operational characteristics by increasing the power output from 134 MW to 197 MW. The stable combustion has been observed in a boiler. With the increase of power output, the exhaust gas temperature was exceeded the design value of $430^{\circ}C$, so the combustion air was taken from atmosphere instead of the boiler penthouse.