• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.405-412
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• 2012

In the MCFC power generation system, the combustor supplies a high temperature mixture of gases to the cathode and heat to the reformer by using the off-gas from the anode; the off-gas includes high concentrations of $H_2O$ and $CO_2$. Since a combustor needs to be operated in a very lean condition and avoid local heating, a catalytic combustor is usually adopted. Catalytic combustion is also generally accepted as one of the environmentally preferred alternatives for generation of heat and power from fossil fuels because of its complete combustion and low emissions of pollutants such as CO, UHC, and $NO_x$. In this study, experiments were conducted on catalytic combustion behavior in the presence of Pd-based catalysts for the BOP (Balance Of Plant) of 5 kW MCFC (Molten Carbonate Fuel Cell) power generation systems. Extensive investigations were carried out on the catalyst performance with the gaseous $CH_4$ fuel by changing such various parameters as $H_2$ addition, inlet temperature, excess air ratio, space velocity, catalyst type, and start-up schedule of the pilot system adopted in the BOP.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.421-422
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• 2000

VOCs 처리기술로는 촉매연소, 열적처리, 생물학적처리법 등이 있으며, 촉매연소방법의 경우 저온에서 처리가 가능하여 처리비용 절감 등의 효과를 고려할 때 가장 경제적인 방법으로 평가되고 있다(Guisnet, et al., 1999). VOCs 처리에는 대부분 고가의 귀금속촉매를 많이 사용하므로, 경제적 부담을 줄이기 위하여 귀금속을 담체(SiO$_2$, A1$_2$O$_3$, TiO$_2$등)에 담지시켜 활용하거나, 귀금속촉매를 대체하기 위한 Mn, Co, Cu 등의 금속 산화물 촉매에 대한 연구가 활발히 진행되고 있다. (중략)

• Journal of the Korean Institute of Gas
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• v.5 no.1
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• pp.45-51
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• 2001

Catalytic combustion is the environmental-friendly technology, which has been applied to a variety of areas for industrial and domestic use in recent years. Accordingly, this study performed the development of the catalytic manufacturing technology for the high temperature and of the catalytic combustor in priority, which were aimed to be aimed to a commercialized condensing boiler. Palladium(Pd) of a noble meta] was used as a catalyst for the high temperature and supported on $alumina(Al_{2}O_{3})\;and\;zirconia(ZrO_2)$ in constant weight ratio. Activity of Pd catalysts is compared and analysed in the catalytic combustion of natural gas. The ratio of $Pd/Al_{2}O_{3}\;=\;4$ was found to be better than any other weight ratios in activity and durability. The performance examination of catalysts and of combustion through the plate-type combustor made it possible to be developed the cylindrical-type combustor which has increased combustion area. Catalytic combustion condensing boiler of 25,000 kcal/hr class was also developed, which had the optimum combustion condition at the no221e of 5.95mm and the orifice of 21mm. This condition was determined through the performance experiments of catalytic combustion condensing boiler to which the cylindrical-type catalytic combustor was applied.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.6
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• pp.641-648
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• 2011

Off-gases emitted from the anode of a molten carbonate fuel cell (MCFC) at high temperatures for power generation are used as fuel in catalytic combustion. The heat generated in the catalytic combustor is utilized as the heat for the endothermic reaction required for steam reforming. Among the various operational conditions of the integrated reactor, we varied the inlet gas compositions of the catalytic combustor according to fuel utilization in the MCFC and the ratio of steam to carbon in the reformer. Subsequently, the thermal behaviors and reaction characteristics of the integrated reactor were investigated experimentally. The fundamental data from this experimental study will be useful for the design and fabrication of a more practical integrated reactor in the future.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.1-10
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• 2011

Combustion and extinction limits in heat-recirculating excess enthalpy reactors employing both gas-phase and catalytic reaction have been examined with an emphasis Reynolds number (Re) effects and possible application to microscale combustion devices. In this paper, geometrically similar reactors of different physical sizes and different numbers of turns were tested with the aim of estimating for combustor characteristics. Combustion efficiency is estimated by measuring exhausted gases through the gas chromatograph. From these results the effect of scale and number of turns are demonstrated and optimal operating conditions for Swiss roll combustors are identified.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.169-177
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• 2006

In this study, it was studied that the removal rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC(space velocity and catalyst depth) and the space velocity(SV) was defined by the rate of gas volume flow rate(Q, $m^3/hr$) over volume(V, $m^3$) of catalyst (SV=Q/V). The space velocity of catalytic combustor is maintained $10,000{\sim}50,000hr^{-1}$. it was studied that the conversion rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC and catalyst and the space velocity was defined by the rate of gas volume flow rate over volume of catalyst. The VOC which pass thru the heat exchanger was measured by the hydro ionic detector and measured the VOC removal rate by the activated catalyst in the reaction temperature range of 373K-423K. The removal rate was measured over 100 times. In the automobile painting booth The VOC concentration was 63.37ppm and the removal rate was 70 % at 373K and 78.92% at 423K. The removal rate was increased as increased the temperature.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.34-47
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• 1999

본 연구에서는 촉매상에서 메탄의 산화시 발생되는 반응열을 이용하고 반응생성물과 미반응 메탄과의 개질반응에 의해 합성가스의 수율을 증대시키기 위하여 연소촉매와 개질촉매를 연속적으로 배치한 hybrid 촉매상에서 개질촉매에 따른 메탄의 부분산화반응의 반응 특성과 합성가스 수율에 미치는 영향을 관찰하였다. 메탄의 산화를 위해서 Pt-Rh/cordierite 촉매를 사용하였으며, 개질촉매로는 상업용 개질촉매인 R67, ICI46-1, 수성가스 전환반응촉매인 LX821 촉매와 6 wt% Ni/cordierite 촉매를 사용하였다. 실험결과 연소촉매와 개질촉매를 연속적으로 사용한 경우 메탄의 산화 과정에서 생성된 CO2 및 H2O가 미반응 메탄과의 개질반응 촉진으로 인하여 합성가스이 수율이 증가됨을 확인할 수 있었다. 이때 생성되는 합성가스의 H2/CO 몰비는 온도에 따라 감소하는 것으로 나타났으며, 80$0^{\circ}C$에서 촉매에 따라 2.2~2.8의 값을 가짐을 알 수 있었다. 개질촉매로 R67 및 Ni/cordierite 촉매를 사용하였을 경우 가장 높은 합성가스의 수율을 얻을 수 있었으며, 연소촉매와 개질촉매의 질량비는 1:1~1:2에서 가장 높은 수율의 합성가스를 얻을 수 있었다. 메탄과 산소의 몰비가 2:2에서 메탄의 전환율과 수소 수율이 가장 높게 나타났으며 메탄의 몰비 증가에 따라 감소되는 경향을 보였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.375-381
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• 2010

In this paper, the heat-transfer characteristics of steam reforming in an annular reactor are presented. Heat is supplied by the catalytic combustion of syn-gas. The thermal behaviors of exothermic and endothermic reactions in a directly coupled concentric-tube packed-bed reactor were investigated experimentally. The gas mixture supplied for catalytic combustion consisted of the off-gas emitted from MCFC anode. Methane in steam at a suitable S/C (steam-to-carbon) ratio was used in the reforming reactions. On the basis of the experimental results, a simple simulation was performed to predict the temperature profile required in the reforming side of the reactor to achieve optimum hydrogen yield. The results of this study may be utilized as reference data in future studies for further development of coupled reactors.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.11a
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• pp.193-198
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• 1996

고연소속도 HTPB/AP 추진제를 얻기 위하여 현재 각광받고 있는 3종의 철화합물 연소촉매를 선정하여 연소속도 증진효과와 기계적 특성, 공정성 및 노화특성에 미치는 영향을 검토하였다. 사용한 철 화합물은 HTPB 프리폴리머에 silicone-ferrocene이 그라프트된 $BUTACENE^$\circledR$$ 과 결합제 역할을 하는 acylaziridinyl ferrocene(AAF), 그리고 입자크기가 30nm인 $NANOCAT^$\circledR$$ superfine iron oxide(SFIO)이었다. 이들 철 화합물을 추진제에 적용한 결과 공정성의 경우 $BUTACENE^$\circledR$$ 은 혼합점도가 높았으나 pot life의 감소는 없었으며 AAF와 SFIO는 혼합점도는 비교적 낮은 반면 pot life가 현저히 감소하는 경향을 보였다. 추진제의 노화거동은 연소촉매를 사용하지 않았을 때보다 저하되었으나 metal deactivating 산화방지제인 $PRO-TECH^$\circledR$$ 과 함께 사용할 경우 공정성 및 노화특성 모두 바람직한 수준으로 향상되었다. 기계적 특성은 SFIO를 제외하고는 저하되었으며 $BUTACENE^$\circledR$$ 은 프리폴리머로서, AAF는 결합제로서의 기능이 다소 미흡하였다. 한편 연소촉매의 함량에 따른 촉매효과는 AAF>SFIO>$BUTACENE^$\circledR$$ 순이었고 철 함량 측면에서는 AAF>$BUTACENE^$\circledR$$ >SFIO 순이었다.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.11-18
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• 2011

The geometrically similar swiss roll reactors of different physical sizes were tested with the aim of independently determining the effects of Re and Da. It is found that the difference between catalytic and non-catalytic combustions extinction limits are narrowed as scale decreases. In addition to assess the importance of fuel chemistry, different families of fuels including alkanes and ethers were tested. From these results the effect of scale and fuel type on microscale reactor performance and implications for practical micro combustion devices are discussed.