• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.592-602
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• 2014

In the Integrated Gasification Combined Cycle (IGCC), the stability of the gasifier has strong influences on the rest of the plant as it supplies the feed to the rest of the power generation system. In order to ensure a safe and stable operation of the entrained-flow gasifier and for protection of the gasifier wall from the high internal temperature, the solid slag layer thickness should be regulated tightly but its control is hampered by the lack of on-line measurement for it. In this study, a previously published dynamic simulation model of a Shell-type gasifier is reproduced and two different linear model predictive control strategies are simulated and compared for multivariable control of the entrained-flow gasifier. The first approach is to control a measured secondary variable as a surrogate to the unmeasured slag thickness. The control results of this approach depended strongly on the unmeasured disturbance type. In other words, the slag thickness could not be controlled tightly for a certain type of unmeasured disturbance. The second approach is to estimate the unmeasured slag thickness through the Kalman filter and to use the estimate to predict and control the slag thickness directly. Using the second approach, the slag thickness could be controlled well regardless of the type of unmeasured disturbances.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.639-648
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• 2013

This paper describes on the NOx/CO emission characteristics, temperature characteristics and flame structures when firing coal derived synthetic gas especially for gases of Buggenum and Taean IGCC. These combustion characteristics were observed by conducting ambient-pressure elevated-temperature combustion tests in GE7EA model combustor when varying heat input and nitrogen dilution ratio. Nitrogen addition caused decrement in adiabatic flame temperature, thus resulting in the NOx reduction. At low heat input condition, nitrogen dilution raised the CO emission dramatically due to incomplete combustion. These NOx reduction and CO arising phenomena were observed at certain flame temperature of $1500^{\circ}C$ and $1250^{\circ}C$, respectively. As increasing nitrogen dilution, adiabatic flame temperature and combustor liner temperature were decreased and singular points were detected due to change in flame structure such as flame lifting. From the results, the effect of nitrogen dilution on the NOx/CO and flame structure was examined, and the test data will be utilized as a reference to achieve optimal operating condition of the Taean IGCC demonstration plant.

• NEWSLETTER 전기공업
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• no.92-23 s.66
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• pp.1-21
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• 1992

• Journal of the KSME
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• v.50 no.9
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• pp.43-46
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• 2010

석탄가스화 기술은 석탄가스화복합발전(IGCC), 석탄의 간접액화, 석탄합성가스를 사용한 메탄올 등 화학원료 생산, 천연합성가스(SNG) 생산에 핵심 되는 기술이다. 석탄가스화 기술의 역사는 100년이 넘었지만 현재 사용되는 기술은 반응시간과 규모, 온도 압력 측면 등에서 전혀 다르다. 석탄가스화 기술의 간략한 역사와 최근 석탄가스화 업계 동향, 석탄가스화 분야에서 추진되고 있는 미래기술의 방향을 소개한다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.44-48
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• 1996

본 연구는 석탄가스화복합발전(IGCC) 시스템중 핵심 단위 장치중의 하나인 가스화기 내부에서 일어나는 석탄의 가스화 반응 연구를 PCGC-2 프로그램을 통해 수행하였으며 일차적인 목표로 반응장에서의 선회 강도에 따른 가스화기내 유동 및 반응 특성을 파악하고자 하였다.

• Korean Journal of Materials Research
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• v.18 no.12
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• pp.650-654
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• 2008

The emission of carbon dioxide from the burning of fossil fuels has been identified as a major contributor to green house emissions and subsequent global warming and climate changes. For these reasons, it is necessary to separate and recover $CO_2$ gas. A new process based on gas hydrate crystallization is proposed for the $CO_2$ separation/recovery of the gas mixture. In this study, gas hydrate from $CO_2/H_2$ gas mixtures was formed in a semi-batch stirred vessel at a constant pressure and temperature. This mixture is of interest to $CO_2$ separation and recovery in Integrated Coal Gasification (IGCC) plants. The impact of tetrahydrofuran (THF) on hydrate formation from the $CO_2/H_2$ was observed. The addition of THF not only reduced the equilibrium formation conditions significantly but also helped ease the formation of hydrates. This study illustrates the concept and provides the basic operations of the separation/recovery of $CO_2$ (pre-combustion capture) from a fuel gas ($CO_2/H_2$) mixture.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.2
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• pp.133-140
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• 2008

A reduced chemical kinetic mechanism is developed in order to predict the flame phenomena in premixed $CO/H_2/Air$ flames at atmospheric pressure, aimed at studying the coal gas combustion for the IGCC applications. The reduced mechanism is systematically derived from a full chemical kinetic mechanism involving 11 reacting species and 66 elementary reactions. This mechanism consists of four global steps, and is capable of explicitly calculating the concentration of 7 non-steady species and implicitly predicting the concentration of 3 steady state species. The fuel blend contains two fuels with distinct thermochemical properties, whose contribution to the radical pool in the flame is different. The flame speeds predicted by the reduced mechanism are in good agreement with those by the full mechanism and experimental results. In addition, the concentration profiles of species and temperature are also in good agreement with those by the full mechanism.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.136-140
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• 2010

The integrated gasification combined cycle (IGCC) is one of the most promising proposed processes for advanced electric power generation that is likely to replace conventional coal combustion. This emerging technology will not only improve considerably the thermal efficiency but also reduce or eliminate the environmentally adverse effects normally associated with coal combustion. The IGCC process gasifies coal under reducing conditions with essentially all the sulfur existing in the form of hydrogen sulfide ($H_2S$) in the product fuel gas. The need to remove $H_2S$ from coal derived fuel gases is a significant concern which stems from stringent government regulations and also, from a technical point of view and a need to protect turbines from corrosion. The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream. The sulphidation of waste seashells with $H_2S$ was studied in a thermogravimetric analyzer at temperature between $600^{\circ}C$ and $800^{\circ}C$. The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affects the $H_2S$ removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electronmicroscopy.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.187-193
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• 2002

IGCC (Integrated Gasification Combined Cycle) power plant is becoming more attractive because it allows that various fuels like coal, heavy oil md even residue oil and wood are used in a gas turbine. This paper presents a prediction of performances of gas turbine when low caloric value syngas fuels produced from the IGCC is used in it originally designed with natural gas fuel. Using a systemic method which predicts a gas turbine behavior with limited design data, when natural gas, design fuel and four other types of syngas are used in GE 7FA gas turbine, its performances are predicted on design and off-design conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.54-61
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• 2008

Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increases the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition.