• 공업화학
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• 제23권2호
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• pp.176-182
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• 2012

메탄 개질반응($CH_4$ reforming)은 온실가스($CH_4$와 $CO_2$)를 합성가스(CO, $H_2$)로 전환시켜 온실가스를 자원화 한다는 점에서 활발하게 연구가 진행되고 있다. 그러나 촉매 비활성화와 고온 반응으로 인해 아직 상업화된 공정이 없는 상황이다. 본 연구에서는 Co, Ru, Zr 금속과 담지체로 $SiO_2$를 이용해 Co-Ru-Zr-Si (CRZS)촉매를 제조하고 이를 성형하여 메탄개질반응 특성을 연구하고, 공정 개발을 위한 기초 자료를 얻고자 하였다. 성형촉매의 특성을 알아보기 위해 XRD, BET 그리고 EDS로 분석하였고, 메탄 및 이산화탄소 전환율은 GC (TCD detector)로 분석하였다. 또한 반응속도론적 연구로 부터 반응속도상수를 구하였으며 반응물의 물질전달영향을 받지 않는 촉매크기를 선정하였다. 선정된 성형촉매는 $850^{\circ}C$, 720 h에서도 활성을 유지하였다.

• 한국수소및신에너지학회논문집
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• 제18권4호
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• pp.382-390
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• 2007

To check the feasibility of SMART(Steam Methane Advanced Reforming Technology) system, an experimental investigation was performed. A fluidized bed reactor of diameter 0.052m was operated cyclically up to 10th cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone(domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) condition. The hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased. However, the average hydrogen concentration at 10th cycle was 82.5% and this value is also higher than that of SMR. Based on these results, we could conclude that the SMART system can replace SMR system to generate pure hydrogen without HTS (high tempeature shift), LTS (low temperature shift) and $CO_2$ separation process.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.221-226
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• 2015

Ru catalysts supported on $CeO_2$ were synthesized by an impregnation method and characterized by numerous analytical techniques including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). Upon utilization of these catalysts for methane dry reforming with a $CH_4/CO_2$ ratio of 1:1 at different temperatures ranging from 550 to $750^{\circ}C$, the $Ru/CeO_2$ catalysts have shown to be active. In particular, Ru(0.55wt%) supported on $CeO_2$ (1) prepared by a hydrothermal method exhibited excellent activity with the conversion of > 75% at $750^{\circ}C$. In addition, the catalyst also proved to be highly stable for at least 47 h without catalyst deactivation under the dry reforming conditions.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.554-561
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• 2016

Depending on the Bio-gas sources, main component gases of $CH_4$ and $CO_2$ are shown to be variously present in amounts. For the anaerobic digester, The concentration of $CH_4$ and $CO_2$ in the gases are 60~70 and 30~35 vol%. For the landfill gas, $CH_4$ and $CO_2$ are 40~60 and 40~60 vol%. For the food wastes, $CH_4$ and $CO_2$ are 60~80 and 20~40 vol%, respectively. In this study, maximum conversion rates of $CO_2$ were obtained from the variety of concentrations of $CH_4$ and $CO_2$ by the catalysts of reforming reactions. Moreover, in order to get maximum producing amount of synthetic gas, experimental studies were performed to optimize the reaction variables. On the basis of $CH_4$, 243 ml, R [$CH_4/(O2+CO_2)$] value were varied from 0.8 to 1.35, in the study of $CH_4$ and $CO_2$ reforming reactions. It was shown that the optimal results were obtained for 1.35 of R value. And also, at $850^{\circ}C$ and 1 atm, the production rate of synthetic gas was 90% and the conversion rates of $CH_4$ and $CO_2$ were higher than 99% and 90%, respectively.

• 한국수소및신에너지학회논문집
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• 제25권6호
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• pp.570-576
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• 2014

LFG (Land-Fill Gas) includes components of $CH_4$, $CO_2$, $O_2$, $N_2$, and water. The preparation of synthesis gas from LFG as a DME (Dimethyl Ether) feedstock was studied by methane reforming of $CO_2$, $O_2$ and steam over NiO-MgO-$CeO_2$/$Al_2O_3$ catalyst. Our experiments were performed to investigate the effects of methane conversion and syngas ratio on the amount of LFG components over NiO-MgO-$CeO_2$/$Al_2O_3$ catalyst. Results were obtained through the activity reaction experiments at the temperature of $900^{\circ}C$ and GHSV of 4,000. The results were as following; it has generally shown that methane conversion rate increased with the increase of oxygen and carbon dioxide amounts. Highly methane conversion of 92~93% and syngas ratio of approximately 1.0 were obtained in the feed of gas composition flow-rate of 243ml/min of $CH_4$, 241ml/min of $CO_2$, 195ml/min of $O_2$, 48ml/min of $N_2$, and 360ml/min of water, respectively, under reactor pressure of 15 bar for 50 hrs of reaction time. Also, it was shown that catalyst deactivation by coke formation was reduced by excessively adding oxygen and steam as an oxidizer of the methane reforming.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.31-38
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• 2015

Coking accumulations via dry methane reforming (DMR) over 10NAM monolithic catalyst and pelletized catalyst was investigated. 10NAM catalyst was synthesized and coated on a wall of monolithic reactor. Pelletized catalyst of 10NAM was also prepared for the comparison. Consequently, catalyst was characterized by BET, $H_2-TPR$ and $H_2-TPD$. The catalytic reaction was undergone at $600^{\circ}C$ under atmospheric pressure and $CH_4$ to $CO_2$ reactant ratio of 1:2. The coking formation over spent catalyst was then carried out in the hydrogen flow using temperature programmed technique (TPH). According to the results, DMR over 10NAM monolithic catalyst exhibits a minimized coking formation comparing to the use of pelletized catalyst. This could be attributed to a prominent heat transfer efficiency of the monolithic catalyst.

• 한국수소및신에너지학회논문집
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• 제29권1호
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• pp.1-10
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• 2018

The amount of biogas increases as the amount of organic waste increases. Recently, biogas from organic waste have been made much efforts to utilize as a energy. In particular, the concentration of $CH_4$ and $CO_2$ generated from sewage sludge and livestock manure treatment are 60-70% and 30-35%, and $CH_4$ and $CO_2$ generated from food wastes are 60-80% and 20-40%. In case of landfill gas, $CH_4$ and $CO_2$ have a concentration of 40-60% and 40-60% respectively. Therefore, in order to use the biogas more widely, it is necessary to convert the biogas to methanol, LNG or DME. In this study, experiments were conducted to produce hydrogen and carbon monoxide through various biogas reforming reactions on $Ni/Ce-ZrO_2/Al2O3$ catalysts. The experiment of synthetic gas synthesis was carried out on a wide concentrations of methane and carbon dioxide, which were the major constituents of biogas from various organic wastes. The effect of $(O_2+CO_2)/CH_4$ (=R') on the yields of hydrogen and carbon monoxide, the conversion rate of methane and carbon dioxide was investigated. Also simulation for syngas synthesis on the $CO_2$ reforming of $CH_4$ was computed by employing total Gibbs free energy minimization method using PRO/II simulator, and compared with the experimental results on wet and dry reforming reaction of biogas.

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 춘계 총회 및 학술발표회
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• pp.135-138
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• 1999

• Korean Chemical Engineering Research
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• 제47권3호
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• pp.267-274
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• 2009

온실가스 배출 규제에 따라 이산화탄소 배출 감축은 산업계에서 해결해야 할 가장 중요한 과제 중 하나가 되었다. 이산화탄소는 온실가스 발생원 중 대부분을 차지하며 본 논문에서는 실제 대규모 산업 현장에서의 이산화탄소 배출을 저감하는 직접적인 방안으로 메탄의 이산화탄소 개질 반응을 이용하는 방법을 고찰해 보았다. 강한 흡열 반응 형태인 이 반응에 대해 추가적인 이산화탄소 발생을 피하며 효율적으로 에너지를 공급하기 위해서는 자열 개질 반응을 이용하는 것이 적합한 방법으로 판단된다. 생산된 합성가스는 환원가스로 재활용하거나 화학제품 및 연료의 합성에 활용할 수 있다.

• 한국수소및신에너지학회논문집
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• 제26권5호
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• pp.477-483
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• 2015

LFG (Land-Fill Gas) includes components of $CH_4$, $CO_2$, $O_2$, $N_2$, and water. The preparation of synthesis gas from LFG as a DME (Dimethyl Ether) feedstock was studied by methane reforming of $CO_2$, $O_2$ and steam over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Our experiments were performed to investigate the effects of methane conversion and syngas yield on the amount of LFG components over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Results were obtained through the methan reforming experiments at the temperature of $900^{\circ}C$ and GHSV of 8,800. The results were as following; it has generally shown that syngas yield increase with the increase of oxygen and steam amounts and then decrease. Highly methane conversion of above 98% and syngas yield of approximately 60% were obtained in the feed of gas composition flow-rate of 243ml/min of $CH_4$, 241ml/min of $CO_2$, 195ml/min of $O_2$, 48ml/min of $N_2$, and 450ml/min of steam, respectively, under reactor pressure of 1 bar for 200 hrs of reaction time. Also, it was shown that catalyst deactivation by coke formation was reduced by excessively adding oxygen and steam as an oxidizer of the methane reforming.