• Journal of the Mineralogical Society of Korea
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• v.23 no.3
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• pp.219-225
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• 2010

Optimal grinding condition was examined by changing only the size of screen opening with fixing other factors to produce coal fines of particle sizes required for circulating fluidized bed gasifier. At least 85 wt% of the coal particles should fall into the size range of 0.045~1.0 mm for efficient gasification. In this study, hammer mill was used to grind Chinese low rank lignite coal following grinding condition designed by Taguchi method. The analysis of signal to noise ratio showed that optimum grinding condition for the gasifier was 3 mm in primary screen size and 1.3 mm in secondary screen size on the 95% level of significance.

• Resources Recycling
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• v.20 no.1
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• pp.54-60
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• 2011

The spherical artificial aggregates (AAs) with a diameter of 8 mm, which contains fly ashes discharged from the fluidized bed combustion in a thermal power plant and clay were manufactured by direct sintering method at $1050{\sim}1250^{\circ}C$ for 10 minutes. The effect of fly ash contents on the bloating phenomenon in the AAs was analyzed. The AAs containing fly ash of the amount under 50 wt% showed the black-coring and bloating phenomena. The AAs containing fly ash of the amount over 5Owt%, however, the specific gravity was increased and the color of specimens fully changed to black. These color change phenomena were caused from the formation of FeO by the reduction reaction of almost $Fe_2O_3$ component by the excessive reducing atmosphere formed simultaneously with the rapid emission of the gases generated from the high contents of unburned carbon of with increasing the added fly ash amount. Specific gravity was decreased as fly ash contents increased in the case of sintering at the same temperature condition. Water absorption of all specimens except of the specimens containing 10 wt% fly ashes decreased with increasing sintering temperature. These were because a liquid phase was formed as the increasing the sintering temperature. In the case of the specimens manufactured in this study containing fly ashes discharged from the fluidized bed combustor in a the thermal power plant and 10~90 wt% of clay, the specific gravity was 0.9~1.8 and the water absorptivity was 8~60%, therefore it is considered that those results can be applied to the light or heavy aggregates.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.265-266
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• 2014

Due to global economic growth, there is an increasing need for energy. Fossil fuels will continue to dominate the world energy supplies in the 21st century and coal will play a significant role. Since coal is one of the most important fossil fuels in the world, coal gasification technology appears to be an inevitable choice for power and chemicals production and has a leading place in Clean Coal Technology (CCT). The most eminent environmental advantage of coal gasification lies in its inherent reaction features that produce negligible sulfur and nitrogen oxides, as well as other pollutants in a reducing atmosphere. The gasifier was operated for a throughput of 1.0 ton & 10.0ton coal per day at pressures of 1~20Bar. Gasification was conducted in a temperature range of $1,100{\sim}1,450^{\circ}C$.

• Journal of Energy Engineering
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• v.4 no.3
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• pp.372-378
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• 1995

분류층 석탄가스 반응온도에서 slag의 배출 조건을 원활하게 유지하기 위하여 CaCO3를 flux로 사용한 용융특성을 파악하였다. 첨가에 의한 용융온도는 flux 주입량에 따라 감소하다가 증가하였다. 최저 용융온도의 범위는 ash중 CaO 농도기준 30-40%의 범위에서 나타났으며, Base/Acid ratio에 따라 최소 용융온도는 ash중 무기물간의 eutetic effect가 작용함을 알 수 있었다. 고온에서의 slag 조성은 ash의 조성과 비교시 알카리 산화물의 휘발화와 SO2의 감소를 보여주고 있으며, salg중 환원성 가스가 증가함에 따라 금속 산화물의 환원에 의해 SiO2 조성은 증가하였다. CaCO3를 혼합한 시료를 질소분위기하에서 조제하여 점도를 측정한 결과, low silica ash의 경우 낮은 점도치를 보여주나, 250 poise 이하의 범위에서 고화되는 현상이 발생하였다. high silica ash에서는 CaCO3 투입에 의해 slag 점도는 감소하였는데, slag 분석 결과 CaO가 산소 제공물질(oxide doner)로 작용하여 silicate의 응집현상을 억제하는 것으로 나타났다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.12
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• pp.1000-1006
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• 2009

Integrated Coal Gasification Combined Cycle (IGCC) power plants have been developed to reduce carbon dioxide emissions and to increase the efficiency of electricity generation. A devolatilization process of entrained coal gasification is predicted by CPD model which could describe the devolatilization behavior of rapidly heated coal based on the chemical structure of the coal. This paper is intended to compare the mass release behavior of char, tar and gas(CO, $CO_2,\;H_2O,\;CH_4$) for three different coals. The influence of coal structure on gas evolution is examined over the pressure range of 10${\sim}$30atm.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.83-84
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• 2002

사이클론 집진기(이하 "사이클론"으로 표기)는 1800년대 후반에 기본개념이 싹트기 시작한 이후 100년 이상의 역사를 지닌 집진 장치로서, 구성이 단순하고, 고온 및 고압에서도 동작이 가능하며, 에너지 소모가 적고, 제조비용과 유지비용이 저렴한 특징을 지니고 있다. 현재 산업체에 설치되어 있는 싸이클론은 대용량의 가스처리, 입경 10-200$\mu\textrm{m}$까지의 분진처리, 낮은 초기설치비, 유지보수 및 조작의 간편성 때문에 산업체 여러 분야에서의 응용성은 다양하고 응용범위도 상당히 넓다고 할 수 있으며 석탄가스화 복합발전 플랜트, 쓰레기 소각로, 순환유동층 보일러 등에 널리 사용되고 있다. (중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.5
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• pp.1735-1742
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• 1996

An entrained flow gasifier simulating the cold mode was tested to estimate its performance for coal gasification and flow characteristics with a developed high speed impinging jet nozzle. The burner was designed for high temperature and high pressure(HTHP) conditions, especially for IGCC(Integrated Coal Gasification Combined Cycle). In order to get proper size of droplets for high viscous liquid such as coal slurry, atomization was achieved by impacting slurry with high speed (over 150m/sec) secondary gas (oxygen/or air)/ Formed water droplets were ranged between 100.mu.m to 20.mu.m in their sizes. The flow characteristics in the gasifier was well understood in mixing between fuel and oxidizer. Both external and internal recirculation zones were closely investigated through experimentation with visualization and numerical solutions from FLUENT CODE.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.1
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• pp.124-129
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• 2018

Methane is the cleanest fuel and supplies by many distributed type: liquefaction natural gas (LNG), compressed natural gas (CNG), and pipeline natural gas (PNG). Natural gas is mainly composed by methane and has been discovered in the oil and gas fields. Coal bed methane (CBM) is also one of them which reserved in coalbed. This significant new energy sources has emerge to convert an energy source, hydrogen and hydrogen-driven chemicals. For this CBM, this paper was written to analyze the geological analysis and reserves in Mongolian Tavan Tolgoi CBM coal mine and to examine the application field. This paper is mainly a preliminary feasibility report analyzing the business of Tavan Tolgoi CBM and its exploitable gas.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.1
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• pp.130-137
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• 2018

Now discusses the potential use and applications of coal bed methane (CBM) in various industries. One of the options for gas monetization is gas to power (GTP), sometimes called gas to wire (GTW). Electric power can be an intermediate product, such as in the case of mineral refining in which electricity is used to refine bauxite into aluminum; or it can be an end product that is distributed into a large utility power grid. For stranded gas, away from the regional markets, the integration of the ammonia and urea plants makes commercial sense. These new applications, if established, could lead to a surge in demand for methanol plants.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.3
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• pp.386-401
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• 2011

Mathematical models for various steps in coal gasification reactions were developed and applied to investigate the effects of operation parameters on dynamic behavior of gasification process. Chemical reactions considered in these models were pyrolysis, volatile combustion, water shift reaction, steam-methane reformation, and char gasification. Kinetics of heterogeneous reactions between char and gaseous agents was based on Random pore model. Momentum balance and Stokes' law were used to estimate the residence time of solid particles (char) in an up-flow reactor. The effects of operation parameters on syngas composition, reaction temperature, carbon conversion were verified. Parameters considered here for this purpose were $O_2$-to-coal mass ratio, pressure of reactor, composition of coal, diameter of char particle. On the basis of these parametric studies some quantitative parameter-response relationships were established from both dynamic and steady-state point of view. Without depending on steady state approximation, the present model can describe both transient and long-time limit behavior of the gasification system and accordingly serve as a proto-type dynamic simulator of coal gasification process. Incorporation of heat transfer through heterogenous boundaries, slag formation and steam generation is under progress and additional refinement of mathematical models to reflect the actual design of commercial gasifiers will be made in the near futureK.