• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.158.2-158.2
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• 2011

DME is acronym of dimethyl ether, which is spotlighted as an ideal fuel to produce hydrogen due to its high hydrogen/carbon ratio, high energy density and easiness to carry. In this research, we calculated thermodynamic hydrogen (or syngas) yield from DME autothermal reforming and compared to other fuels. The reforming efficiency was about 80% above $700^{\circ}C$. Lower OCR has higher reforming efficiency but, it requires additional heat supply since the reactions are endothermic. SCR has no significant effect on the reforming efficiency. The optimized condition is $700^{\circ}C$, SCR 1.5, OCR 0.45 without additional heat supply. Comparing to other commercial gaseous fuels (methane and propane), DME has higher selectivity of $H_2O$ and $CO_2$ than the others due to the oxygen atom in the molecule. To apply DME autothermal reforming to real system, a proper catalyst is required. Therefore, it is performed the experiment comparing various novel metal catalysts based on CGO. Experiments were performed at calculated condition. The composition of product was measured and reforming efficiency was calculated. The catalysts have similar efficiency at high temperature(${\sim}800^{\circ}C$) but, CGO-Ru has the highest efficiency at low temperature ($600^{\circ}C$).

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.451-454
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• 2006

WGS reaction over Mo2C and ceria based catalysts was investigated to develop an alternative commercial Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station. The Mo2C catalysts were prepared by a temperature programmed method and the various metal supported cerium oxide catalysts were prepared by an Impregnation method. The catalysts were characterized by the N2 physisorption, Co chemisorption, XRD, TEM and TPR. It was found that Mo2C and 0.2wt% Pt-40wt%, Ni/CeO2 catalysts had higher activity and stability than the Cu-Zn/Al203 above $260^{\circ}C$. Moreover, CO conversion of more than 85% was observed at $280{\sim}300^{\circ}C$. But all catalysts were deactivated during the thermal cycling runs. The results suggest that these catalysts are an attractive candidate for the alternative Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station applications.

• New & Renewable Energy
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• v.4 no.4
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• pp.80-87
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• 2008

Steam reforming of LPG was investigated over spc-Ni/MgAl catalyst in a temperature range of $600{\sim}850^{\circ}C$, feed molar ratio of $H_2O/C=1.0{\sim}3.0$, space velocity of $10,000{\sim}90,000h^{-1}$ and at atmospheric pressure. spc-Ni/MgAl catalyst was prepared by a co-precipitation method, whereas Ni/MgO and $Ni/Al_2O_3$ catalysts were prepared by an incipient wetness method. The characteristics of catalysts were analyzed by N2 Physisorption, CO chemisorption, XRD, TOF-SIMS, SEM and TEM techniques. The Ni/MgO and $Ni/Al_2O_3$ catalysts were deactivated by the formation of carbon. However, the spc-Ni/MgAl catalyst showed higher conversion and $H_2$ selectivity than the other catalysts, even though carbon was formed on the surface of the catalyst during the reaction under the tested reaction conditions.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.97.2-97.2
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• 2011

Pt-Ru and Pt-Ni bimetallic catalysts were prepared and tested for heavy hydrocarbon reforming. Metals were supported on CGO($Ce_{0.8}Gd_{0.2}O_{2.0-x}$) by incipient wetness method. The prepared catalysts were characterized by Temperature programmed reduction(TPR). Oxidative steam reforming of n-dodecane was conducted to compare the activity of the catalysts. The reforming temperature was varied from $500^{\circ}C$ to $800^{\circ}C$ at fixed $O_2$/C of 0.3, $H_2O$/C of 3.0 and GHSV of 5,000/h.Reduction peaks of metal oxide, surface CGO and bulk CGO were detected. Reduction temperature of metal oxide decreased over the bi-metallic catalysts. It is considered that interaction between metals leads to decrease interaction between metal and oxygen. On the other hands, reduction temperatures of surface CGO were dectected in the order of Pt-Ru > Pt-Ni > Pt. low reduction temperatures of surface CGO indicates the low activation energy for oxygen ion conduction to metal. Oxygen ion conduction is known as de-coking mechanism of ionic conducting supports such as CGO. In activity test, fuel conversion was in the same order of Pt-Ru > Pt-Ni > Pt. Especially, 100% of fuel conversion was obtained over Pt-Ru catalysts at $500^{\circ}C$.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.3
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• pp.214-223
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• 2002

Kinetic and effectiveness factors for methanol steam reforming using commercial copper-containing catalysts in a plug flow reactor were investigated over the temperature ranges of $180-250^{\circ}C$ at atmospheric pressure. The selectivity of $CO_2$/$H_2$ was almost 100%, and CO products were not observed under reaction conditions employed in this work. It was indicated that $CO_2$ was directly produced and CO was formed via the reverse water gas shift reaction after methanol steam reforming. The intrinsic kinetics for such reactions were well described by the Langmuir-Hinshelwood model based on the dual-site mechanism. The six parameters in this model, including the activation energy of 103kJ/mol, were estimated from diffusion-free data. The significant effect of internal diffusion was observed for temperature higher than $230^{\circ}C$ or particle sizes larger than 0.36mm. In the diflusion-limited case, this model combined with internal effectiveness factors was also found to be good agreement with experimental data.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.6
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• pp.519-525
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• 2009

The catalytic steam reforming of woody biomass tar and soot to convert a synthetic gas containing hydrogen was investigated by using a bench-scale biomass gasification system. One commercial nickel-based catalyst, Katalco 46-6Q, and two different kinds of natural minerals, dolomite and olivine, were tested as a reforming catalyst at various reforming temperatures. The reaction characteristics of woody biomass tar were also investigated by TGA at a variety of heating rates. With all three catalysts conversion efficiency of tar and soot increased at increasing temperature. The reforming of tar and soot in the synthetic gas induce the increase of combustible gases such as $H_2$, CO and $CH_4$ in the product gas. The nickel-based catalyst showed a higher tar and soot conversion efficiency than mineral catalysts under the same temperature conditions.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.412-418
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• 2010

Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at $900^{\circ}C$ at atmospheric pressure with space velocity of $10,000h^{-1}$ and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by $N_2$-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/$\gamma-Al_2O_3$ catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.4
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• pp.364-377
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• 2014

The performances of a coupled reactor in which a steam reformer and a catalytic combustor were mounted simultaneously had been investigated and compared. The combustible offgas exhausted from the anode of SOFC and MCFC were utilized as heat sources for the endothermic steam methane reforming. The catalytic combustion was used in order to burn the combustible offgas. Thermal energy released by the catalytic combustion is directly transferred to the reformer surrounding the combustor. The various operational conditions such as fuel utilization rate, steam to carbon ratio, amount of catalysts, fuel cell loads were changed. And operating variables were comprehensively identified by sensitivity analysis. The fundamental results from this experimental study show the potential abilities of the coupled reactor. Therefore the results will be of help to design and manufacture the more better coupled reactor in the future.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.202-209
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• 2020

In methanol steam reforming, commercial catalysts in the form of pellets are mainly used, but there are limitations to directly apply them to underwater weapon systems that require shock resistance and heat transfer characteristics. In this study, to overcome this problem, a multi-layer cup structure (MLCS) was applied to support a pellet type catalyst. The characteristics of pellet catalyst supported by MLCS and the pellet catalyst supported by conventional structure (CS) were compared by the reforming experiment. In the case of MLCS, a high methanol conversion rate was shown in the temperature range 200 to 300℃ relative to the CS manufactured with the same catalyst weight as MLCS. CS shown similar characteristics to MLCS when it manufactured in the same volume as MLCS by adding an additional 67% of the catalyst. In conclusions, MLCS can not only reduce catalyst usage by improving heat transfer characteristics, but also support pellet catalyst in multiple layers, thus improving shock resistance characteristics.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.209-219
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• 2019

Methanol is a liquid fuel which could also be produced from renewable energy sources and has appreciably high energy density. In this work, we investigated the application of $Ce_{0.9}Gd_{0.1}O_{2-x}$ supported Cu and Ni catalysts for hydrogen production via methanol steam reforming. Catalysts were synthesized by solution combustion synthesis. The prepared catalysts with various active materials and Cu loading amounts were tested in a reactor at $200-300^{\circ}C$, 0-5 barg range and steam to methanol molar ratio was 1.5. The catalytic properties of Cu and Ni were compared, and the catalytic performance was shown to depend on the amounts of metal loading and operating conditions such as reaction temperature and pressure.