• Resources Recycling
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• v.19 no.5
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• pp.31-43
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• 2010

To fabricate porous SiC candle filter for filtration facility of the IGCC system, the candle type filter preforms were fabricated by ramming and vacuum extrusion process. A commercially available ${\alpha}$-SiC powders with various particle size were used as starting raw materials, and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as non-clay based inorganic sintering additive. The candle typed preforms by ramming process and vacuum extrusion were sintered at $1400^{\circ}C$ for 2h in air atmosphere. The effect of forming method and particle size of filter matrix on porosity, density, strength (flexural and compressive strength) and microstructure of the sintered porous SiC candle tilters were investigated. The sintered porous SiC filters which were fabricated by ramming process have more higher density and strength than extruded filter in same particle size of the matrix, and its maximum density and 3-point bending strength were $2.00\;g/cm^3$ and 45 MPa, respectively. Also, corrosion test of the sintered candle filter specimens by different forming method was performed at $600^{\circ}C$ for 2400h using IGCC syngas atmosphere for estimation of long-term reliability of the candle filter matrix.

• Journal of Hydrogen and New Energy
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• v.22 no.6
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• pp.913-924
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• 2011

A steady-state analysis has been conducted to predict the behavior of the slag layer in the entrained-flow slagging coal gasifier. The analysis takes into consideration the composition dependent slag properties such as density, viscosity, heat capacity, thermal conductivity, and temperature of critical viscosity. The amount of added flux to the design coal and the variation of syngas temperature inside the gasifier have been adopted as calculation parameters. The predicted results are the local thickness of the molten and the solid slag layers, and the slag viscosity and the velocity distribution across the molten slag layer along the gasifier wall near the slag tap.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.356-362
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• 2006

The $SO_2$ reduction using CO and $H_2$ over Sn-Zr based catalysts was performed in this study. Sn-Zr based catalysts with Sn/Zr molar ratio (0/1, 1/4, 1/1, 2/1, 3/1, 1/0) were prepared by the precipitation and co-precipitation method. The effect of the temperature on the reaction characteristics of the $SO_2$ reduction with a reducing agent such as $H_2$ and CO was investigated under the conditions of space velocity of $10,000ml/g_{-cat.}h$, $([CO(or\;H_2)]/[SO_2])$ of 2.0. As a result, the activity of Sn-Zr based catalysts were higher than $SnO_2$ and $ZrO_2$. The reactivity for the $SO_2$ reduction with CO was higher than that with $H_2$, and sulfur yield in the $SO_2$ reduction by $H_2$ was higher than that by CO. The reactivity for the $SO_2$ reduction with $H_2$ was increased with the reaction temperature regardless of Sn-Zr based catalyst with a Sn/Zr molar ratio. $SnO_2-ZrO_2$ (Sn/Zr=1/4) had highest activity at $550^{\circ}C$, in the $SO_2$ reduction with $H_2$ and $SO_2$ conversion of 94.4％ and sulfur yield of 66.4％ were obtained at $550^{\circ}C$. On the other hand, in the $SO_2$ reduction by CO, the reactivity was decreased with the increase over $325^{\circ}C$. At the optimal temperature of $325^{\circ}C$, $SO_2$ conversion and sulfur yield were about 100％ and 99.5％, respectively, in the $SO_2$ reduction over $SnO_2-ZrO_2$ (Sn/Zr=3/1). Also, the $SO_2$ reduction using syngas with $CO/H_2$ ratio over $SnO_2-ZrO_2$ (Sn/Zr=2/1) was performed in order to investigate the application possibility of the simulated coal gas as the reductant in DSRP. As a result, the reactivity of the $SO_2$ reduction using syngas with $CO/H_2$ ratio was increased with increasing the CO content of syngas. Therefore, it could be known that DSRP using the simulated coal gas over Sn-Zr based catalyst is possible to be realized in IGCC system

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.121.2-121.2
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• 2011

석탄가스화복합발전과 연계하여 사용할 수 있는 $CO_2$분리법으로 연소 전 탈탄소화는 연료가 연소되기 전에 $CO_2$를 회수하는 방법으로 현재 여러가지 분리법이 사용되고 있다. 본 연구에서는 가스 하이드레이트의 다양한 응용 분야 중 이산화탄소 격리분야에서 합성가스로부터 $CO_2$롤 효과적으로 분리/회수하기 위하여 가스 고형화법에 관한 연구를 진행하였다. 가스 하이드레이트 형성과정에서의 반응 특성을 살펴보기 위하여 순수계와 촉진제 첨가계(TBAB, TBAF, THF)에 대하여 반응시간에 따른 가스소모량 및 기상의 $CO_2$ 조성 변화를 측정하였다. 그 결과 하이드레이트 상에 고농도의 $CO_2$가 포집되는 것을 확인 할 수 있었다. 순수계와 THF 첨가계의 경우 가스 소모량이 다른 계에 비하여 높게 나타났다. 이는 순수계의 경우 구조-I의 큰 동공과 작은 동공에 모두 기체가 점유되기 때문이며, THF 첨가계의 경우 구조-II의 큰 동공에만 기체가 점유되지만 THF의 첨가로 인해 전환율이 증가되기 때문이다. 반면, TBAF와 TBAB 첨가계의 경우에는 상재적으로 낮은 가스 소모량을 보였다. 기체 소모량이 큰 경우 최종 기상의 $CO_2$ 조성이 낮게 나타났다. 그리고 모든 실험조건에서 1시간 이내에 하이드레이트 형성반응이 종결되는 것을 확인할 수 있었다. 또한, 촉진제 첨가에 의한 하이드레이트의 구조적인 변화를 확인하기 위하여 Raman 분광법과 $^1H$-NMR을 이용하여 혼합가스 하이드레이트를 분석하였다. 본 실험으로 얻어진 결과는 가스 고형화법을 이용한 합성가스 분리 공정 설계 및 개발에 중요한 기초자료가 될 것으로 사료된다.

• Journal of Hydrogen and New Energy
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• v.21 no.5
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• pp.425-434
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• 2010

Integrated gasification combined cycle (IGCC) is an efficient and environment-friendly power generation system which is capable of burning low-ranked coals and other renewable resources such as biofuels, petcokes and residues. In this study some process modeling on a conceptual entrained flow gasifier was conducted using the ASPEN Plus process simulator. This model is composed of three major steps; initial coal pyrolysis, combustion of volatile components, and gasification of char particles. One of the purposes of this study is to develop an effective and versatile simulation model applicable to numerous configurations of coal gasification systems. Our model does not depend on the hypothesis of chemical equilibrium as it can trace the exact reaction kinetics and incorporate the residence time calculation of solid particles in the reactors. Comparisons with previously reported models and experimental results also showed that the predictions by our model were pretty reasonable in estimating the products and the conditions of gasification processes. Verification of the accuracy of our model was mainly based upon how closely it predicts the syngas composition in the gasifier outlet. Lastly the effects of change oxygen are studied by sensitivity analysis using the developed model.