• Journal of Energy Engineering
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• 제20권3호
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• pp.231-235
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• 2011

Ligneous biomass such as wood pellet is characterized as carbon neutral which has no carbon dioxide emission ; additionally, it can be used as an alternative fuel by co-firing without additional plant reformation as well as for maintaining stability of fuel supply. We can develop CDM project while co-firing by using biomass into conventional coal fired thermal power plant with AM0085 CDM methodology, and it's possible to prove additionality as fuel cost per kWh is higher than bituminous. The study shows that the electricity by biomass can reduce green house emission by $0.6737tCO_2$ per MWh.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1742-1743
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• 2005

신재생에너지는 화석에너지인 석유, 석탄을 대체하며 이산화탄소를 발생하지 않는 청정에너지로 다양한 분야에 적용, 보급되고 있다. 국내 보급된 태양광, 풍력 발전등의 에너지원은 국책, 시범사업등을 통해 소규모에서 대규모 발전에 이르기 까지 국내 각 지역에서 가동되고 있다. 하지만, 이들 시스템은 독자적인 발전을 이룰 뿐 전체적인 통한 관리가 이뤄지지 못하고 있다. 본 논문에서는 지역별로 운영되는 시스템의 통합관리 운영방안과 네트웍 구축 방안을 도출하고자 한다.

• Clean Technology
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• 제21권1호
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• pp.53-61
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• 2015

In this study, we have investigated the kinetics on the char-CO₂ catalytic gasification reaction. Thermogravimetric analysis (TGA) experiments were carried out for char-CO₂ catalytic gasification of an Indonesian Kideco sub-bituminous. Na₂CO₃ and K₂CO₃ were selected as catalysts which were physically mixed with coal. The char-CO₂ catalytic gasification reaction showed a rapid increase of carbon conversion rate at 850 ℃, 60 vol% CO₂, and 7 wt% Na₂CO₃. At the isothermal conditions ranging from 750 ℃ to 900 ℃, the carbon conversion rates increased as the temperature increased. Four kinetic models for gas-solid reaction including the shrinking core model (SCM), random pore model (RPM), volumetric reaction model (VRM), and modified volumetric reaction model (MVRM) were applied to the experimental data against the measured kinetic data. The gasification kinetics were suitably described by the MVRM for the Kideco sub-bituminous. The activation energies for each char mixed with Na₂CO₃ and K₂CO₃ were found 55-71 kJ/mol and 69-87 kJ/mol.

• Clean Technology
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• 제24권4호
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• pp.315-322
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• 2018

Industrial use of waste oyster shells is limited because of requiring excessive energy for converting natural oyster shells in the form of calcium carbonate ($CaCO_3$) into calcium oxide (CaO) for this purpose. This study aimed to develop energy-saving process for producing solidifying agent using waste oyster shells for backfill materials. It was suggested that oyster shells were converted to calcium sulfates which were mixed with sodium hydroxide solution and red clay, forming solid specimen. The optimal concentrations of sulfuric acid for sulfation of oyster shell and sodium hydroxide to generate calcium hydroxide ($Ca(OH)_2$), were determined. Unconfined compressive strength of solid specimen increased with increasing the content of solidifying agent while it increased also with increasing ratio of natural oyster shells to coal ash. The result clearly demonstrates that solidifying agent consisting of sulfuric acid-treated oyster shell, coal ash, and sodium hydroxide solution, can be effectively utilized for preparing backfill materials using natural oyster shell and coal ash. Sulfuric acid-treated oyster shell-based solidifying agent has not been previously developed and will contribute to broaden industrial application of waste oyster shells.

• Clean Technology
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• 제29권4호
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• pp.279-287
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• 2023

Fine dust emitted from coal combustion is classified into filterable particulate matter (FPM) and condensable particulate matter (CPM). CPM is difficult to control with existing air pollution control devices, so research is being conducted to understand the characteristics of CPM. Components constituting condensable particulate matter (CPM) are divided into inorganic and organic components. There are many quantitative analysis results for the ionic components, which account for a significant proportion of the CPM inorganic components, but little is known about the organic components. Thus, there is a need for a quantitative analysis of CPM organic components. In this study, aromatic hydrocarbons (toluene, ethyl benzene, m,p-xylene, and o-xylene) and n-alkanes with 10 to 30 carbon atoms were quantitatively analyzed to understand the organic components of CPM emitted from a lab-scale coal combustor. Of the aromatic hydrocarbons, toluene accounted for 1.03% of the CPM organic components. On the other hand, the contents of ethyl benzene, m,p-xylene, and o-xylene showed low values of 0.11%, 0.18%, and 0.51% on average, respectively. Among the n-alkanes, triacontane (C₃₀) showed a high content of 2.64% and decane (C₁₀) showed a content of 2.05%. The next highest contents were shown with dodecane (C₁₂), tetradecane (C₁₄), and heptacosane (C₂₇), all of which were higher than that of toluene. The n-alkane substances that had detectable concentrations showed higher contents than ethyl benzene, m,p-xylene, and o-xylene except for tetracosane (C₂₄).

• Clean Technology
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• 제23권4호
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• pp.413-420
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• 2017

The batch experiments and response surface methodology (RSM) have been applied to the investigation of the Cs adsorption with zeolite X synthesized using coal fly ash generated from the thermal power plant. Regression equation formulated for Cs adsorption was represented as a function of response variables. The model was highly relevant because the decision coefficient ($r^2$) was 0.9630. It was confirmed from the statistical results that the removal efficiency of Cs was affected by the order of experimental factors as pH > Cs concentration > temperature. The adsorption kinetics were more accurately represented by a pseudo second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was $151.52mg\;g^{-1}$ at 293 K. Also, according to the thermodynamic parameters calculated from Vant Hoff equation, it could be confirmed that the adsorption reaction was an endothermic reaction and a spontaneous process.

• Clean Technology
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• 제24권4호
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• pp.287-292
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• 2018

Effect of physical property of activated carbon on its carbon dioxide adsorption was investigated for the effective control of carbon dioxide. Pinewood sawdust and coal were used as raw materials of activated carbon. Specific surface area, micropore volume and mesopore volume of the prepared activated carbons were determined, respectively. The prepared activated carbons were analyzed for their adsorption capacity of carbon dioxide. The adsorption capacity was then presented with respect to the surface area, micropore volume and mesopore volume, respectively. As a result, the specific surface area and micropore volume of both pinewood and coal activated carbon were highly related to its carbon dioxide capacity. Its mesopore volume hardly affected its carbon dioxide capacity. Preparation of activated carbon with high specific surface area and micropore volume was found to be critical to the effective control of carbon dioxide.

• Journal of Energy Engineering
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• 제24권3호
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• pp.150-163
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• 2015

Gasification technology is one of the representative next-generation fossil fuel utilization technologies, converting low grade fossil fuels such as coal, heavy residue oil, pet-coke into highly clean and efficient energy sources. Accordingly, related market demand for gasification technology is ever increasing steadily and rapidly. A few years ago, conventional pulverized coal utilization technology had an edge over the gasification technology but the most significant technical barrier of limited capacity and availability has been largely overcome nowadays. Futhermore, it will be more competitive in the future with the advancement of related technologies such as gas turbine, ion transfer membrane and so on. China has recently completed a commercialization-capable large-scale coal gasification technology for its domestic market expansion and foreign export, rapidly becoming a newcomer in the field and competing with existing US and EU technical leadership at comparable terms. Techno-economic aspect deserves intensive attention and steady R&D efforts need to continue in organized, considering that gasification technology is quite attractive combined with $CO_2$ capture process and coal to SNG plant is economically viable in Korea where natural gas is very expensive. In the present paper, recent technology development and commercialization trend of many leading companies with coal gasification expertise have been reviewed with significant portion of literature cited from the recently held '2014 Gasification Technology Conference'.

• Journal of Energy Engineering
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• 제22권2호
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• pp.96-104
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• 2013

Coal gasification is considered as one of the best alternatives among clean coal technology and new concept next generation technologies are under being developed to achieve low cost as well as high efficiency. In this study we have developed double swirl multi-burner as part of the development of low cost compact gasifier. We installed new concept multi-burner with pulverized coal distributor to the body of existing gasifier for burner test. Gasification test was performed under the condition of $6.4{\sim}7.2kg/cm^2$ and $1170{\sim}1300^{\circ}C$ by using Indonesian ABK (sub-bituminous) coal to get operation condition of new concept multi-burner. Our interest was focused to ensure a stable operating condition rather than the gasifier performance evaluation. As a result, we were able to achieve the carbon conversion of 84% and the cold gas efficiency of 52.1% at the stable operating conditions.

• Journal of the Mineralogical Society of Korea
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• 제23권3호
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• pp.199-209
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• 2010

Coal gasification technology in the sector of domestic clean coal technologies is being into the limelight since recent dramatic rise of international oil price. In this study, we used a low rank coal from Inner Mongolia, China as a starting material for gasification. Various properties including optical, mineralogical, X-ray spectroscopic, X-ray diffraction, and drying property were measured and tested in order to estimate the suitability of the coal to gasification. The coal was identified as a brown coal of lignite group from the measurement of vitrinite reflectance. The coal has very low slagging and fouling potentials, and the ignition temperature is about $250^{\circ}C$. The major impurities consist of quartz, siderite, and clay minerals. Additionally, the coal had moisture content above 28%. Tests for finding effective drying method showed that the microwave drying is more effective than thermal drying.