• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.111-114
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• 2012

The ignition behavior of single coal particles of five kindes of coal with different ranks (low volatile bituminous, low volatile sub-bituminous, high volatile bituminous, lignite) with particle size of $150-200{\mu}m$ was investigated at high heating rate condition. Particles were injected into a laminar flow reactor and the ignition behavior was observed with high speed cinematography. Sub-bituminous were observed to ignite homogeneously; however, low volatile bituminous coal and lignite undergo fragmentation prior to igntion. The observation was analyzed with previous work.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.11-20
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• 2015

In the present work, a basic study on the in-situ biogenic methane generation from low grade coal bed was conducted. Lignite from Indonesia was used as a sample feedstock. A series of BMP (Biochemical Methane Potential) tests were carried out under the different experimental conditions. Although nutrients and anaerobic digester sludge were added to the coal, the produced amount of methane was limited. Both temperature control and particle size reduction showed little effect on the increase of methane potential. When rice straw was added to lignite as an external carbon source, methane yield of 94.4~110.4 mL/g VS was obtained after 60 days of BMP test. The calorific value of lignite after BMP test decreased (4.5~12.1 %) as increasing the content of rice straw (12.5~50 wt % of lignite), implying that anaerobic digestion of rice straw led to partial degradation of lignite. Therefore, rice straw could be used as an external carbon source for the start-up of in-situ biogas generation from low grade coal bed.

• Journal of Animal Environmental Science
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• v.5 no.2
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• pp.101-106
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• 1999

This study was conducted to develop a lignite coal heater which can be used to livestock facilities and to test performance of the heater developed. Experimental results are as following: 1. Heating capacity of the heater was 85,000 kcal/h. 2. The concentrations of CO gas in the exhaust gas were the maximum of 759 ppm and the average of 319 ppm; for the concentrations of NOx, the maximum of 212 ppm and the average of 57 ppm ; for the concentrations of SO2 gas, the maximum of 302 ppm and the average of 99 ppm. As the values were less than the allowable concentration limites, they did not violate the air environment law. 3. Problems such as frequent interruption of fuel supply and bridge state were happened. Therefore, it was required that these should be resolved in the future.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.1
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• pp.63-70
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• 2016

In this study, ash free coals(AFCs) were produced with lignite and anthracite coals in a microwave. The AFCs were analyzed with proximate analysis, fourier transform infrared spectrometry (FTIR), X-ray diffraction analysis, and thermogravimetric analysis (TGA). The extraction yields of the AFCs were 16.4 wt%, 7.6 wt% at lignite and anthracite coal, respectively. The chemical and physical properties of the AFCs were similar regardless of the original coal types. Oxidation behavior of the AFCs was investigated by supplying a mixture of 3g of AFC and 3g of electrolyte into the coin-type molten carbonate fuel cell (MCFC). For the evaluation of AFC fuel performance, electrochemical analysis of the steady-state polarization and step-chronopotentiometry were conducted based on the standard hydrogen fuel (69 mol% $H_2$, 17 mol% $CO_2$, 14 mol% $H_2O$). The AFCs showed similar electrochemical oxidation behaviors regardless of the original coal types. The overvoltage of the AFCs was larger than the hydrogen fuel, although OCV of the AFCs was higher.

• KSBB Journal
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• v.7 no.1
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• pp.73-78
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• 1992

The solubilizations of Australian lignite by the fungus Poria cocos, Trichodermareesei, Candide tropicalis, and niger were investigated. Three different types of chemical pretreatment methods were used for increasing biosolubility of lignite. Nitric acid and hydrogen peroxide were proven to be proper chemical pretreatment materials of Australian lignite. Poria cocos showed much better solubilization ability than other strains. Interpretation of the nature of coal solubilization by Poria cocos was based primarily on infrared, ultraviolet and nuclear magnetic resonance spectrum analyses.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.80-87
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• 2010

Lignite of low rank coal and petroleum coke of high sulfur content can be high potential energy sources for coal gasification process because of their plentiful supply. The kinetic study of steam gasification has been performed in an atmospheric thermobalance with wood chip, lignite, bituminous, anthracite, pet-coke. The effects of gasification temperature($600{\sim}850^{\circ}C$) and partial pressure of steam(30~90 kPa) on the gasification rate have been investigated. The modified volumetric reaction model was applied to the experimental data to describe the behavior of carbon conversion and to evaluate the needed kinetic parameters. Lignite and wood chip with high volatile content showed high average gasification rates comparing to other fuel and thus they might be proper fuel for gasification processes. The activation energies for wood chip, lignite, bituminous, anthracite, and pet-coke through Arrhenius plot were found to be 260.3, 167.9, 134.6, 82.2, 168.9 kJ/mol, respectively. The expression of apparent reaction rates for steam gasification of various chars have been proposed as basic information for the design of coal gasification processes.

• Journal of the Korean Chemical Society
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• v.4 no.1
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• pp.78-80
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• 1957

Up to now, only superficial studies on the combustion velocity of smokeless fuels have been reported, while it should be a basical factor on the utilization of low quality coals and some other smokeless solid fuels. It was, therefore, difficult to choose raw material coals in manufacturing gaseous fuels. With the intent to solve above problem, we have determined combustion velocity of domestic anthracites, graphites, coalites of lignite and cokes from Japanese bituminous coal. The results show that the cokes from Japanese bituminous coal which has been used as raw material in the manufacturing gaseous fuels such as water gas, or producer gas in Korea can be replaced by some sources of domestic anthracite or coalite of lignite.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.06b
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• pp.142-147
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• 1998

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1015-1020
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• 2012

Lignite of low rank coal and petroleum coke of high sulfur content can be high potential energy sources for coal gasification process because of their plentiful supply. The steam gasification of lignite, anthracite, and pet coke has been carried out in both an atmospheric thermobalance reactor and a lab-scale fludized bed reactor (0.02 m i.d. ${\times}$ 0.6 m height). The effects of gasification temperature ($600{\sim}900^{\circ}C$) and partial pressure of steam (0.15~0.95 atm) on the gasification rate and on the heating value of product gas have been investigated. The modified volumetric reaction model was applied to the experimental data to describe the behavior of carbon conversion, and to evaluate kinetic parameters of char gasification. The results shows that higher temperature bring more hydrogen in the product syngas, and thus increased gas heating value. The feed rate of steam is needed to be optimized because an excess steam input would lower the gasification temperature which results in a degradation of fuel quality. The rank of calorific value of the product gas was anthracite > lignite > pet coke. Their obtained calorific value at $900^{\circ}C$ with 95% steam feed were 10.0 > 6.9 > 5.7 $MJ/m^3$. This study indicates that lignite and pet coke has a potential in fuel gas production.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.114-119
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• 2011

Thermogravimetric analysis(TGA) was carried out for pyrolysis and char-$CO_2$ gasification of low rank Indonesian ABK coal and China lignite. The pyrolysis rate was successfully described by a two-step model adopting the modified Kissinger method. The shrinking core model, when applied to char-$CO_2$ gasification gave initial activation energy of 189.1 kJ/mol and 260.5 kJ/mol for the ABK coal and China lignite, respectively. Thus, the char-$CO_2$ gasification has been successfully simulated by the shrinking core model. In particular, the activation energy of char-$CO_2$ gasification calculated in this work is similar to the results on the anthracite coal, but considerable difference exists when other models or coal types are used.