• Transactions of the Korean hydrogen and new energy society
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• v.18 no.2
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• pp.132-139
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• 2007

Popular techniques for producing synthesis gas by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and for application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC Glidarc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Glidarc plasma reformer was consisted of 3 electrodes and an AC power source. And air was added for the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 36.2% and 35.2% respectively.

• Clean Technology
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• v.23 no.1
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• pp.104-112
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• 2017

Hydrogen production via steam reforming of liquefaction liquid from marine algae over hydrothermal liquefaction was carried out at 873 ~ 1073 K with a commercial catalyst and Ni based $K_2Ti_xO_y$ added catalysts. Liquefaction liquid obtained by hydrothermal liquefaction (503 K, 2 h) was used as a reactant and comparison studies for catalytic activity over different catalysts (FCR-4-02, $Ni/K_2Ti_xO_y-Al_2O_3$, $Ni/K_2Ti_xO_y-SiO_2$, $Ni/K_2Ti_xO_y-ZrO_2/CeO_2$ and Ni/$K_2Ti_xO_y$-MgO), reaction temperature were performed. Experimental results showed Ni/$K_2Ti_xO_y$ based catalysts ($Ni/K_2Ti_xO_y-Al_2O_3$, $Ni/K_2Ti_xO_y-SiO_2$, Ni/$K_2Ti_xO_y-ZrO_2$/ $CeO_2$ and Ni/$K_2Ti_xO_y$-MgO) have a higher activity than commercial catalyst (FCR-4-02) and In particular, a product composition was different depending on support materials. An acidic support ($Al_2O_3$) and a basic support (MgO) led to a higher selectivity for CO while a neutral support ($SiO_2$) and a reducing support ($ZrO_2/CeO_2$) resulted in a higher $CO_2$ selectivity due to water gas shift reaction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.793-799
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• 2016

In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.889-892
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• 2009

A microwave plasma torch at the atmospheric pressure by making use of magnetrons operated at the 2.45 GHz and used in a home microwave oven has been developed. This electrodeless torch can be used to various areas, including industrial, environmental and military applications. Although the microwave plasma torch has many applications, we in the present work focused on the microwave plasma torch operated in pure steam and several applications, which may be used in future and right now. For example, a high-temperature steam microwave plasma torch may have a potential application of the hydrocarbon fuel reforming at one atmospheric pressure. Moreover, the radicals including hydrogen, oxygen and hydroxide molecules are abundantly available in the steam torch, dramatically enhancing the reaction speed. Also, the microwave plasma torch can be used as a high-temperature, large-volume plasma burner by injecting hydrocarbon fuels in gas, liquid, and solid into the plasma flame. Lastly, we briefly report an underway research, which is remediation of soils contaminated with oils, volatile organic compounds, heavy metals, etc.

• Journal of Electrochemical Science and Technology
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• v.7 no.2
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• pp.146-152
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• 2016

A combined system with PEMFC and reformer is introduced and optimized for the real use of this kind of system in the future. The hydrogen source to operate the PEMFC system is methanol, which needs two parts of methanol reforming reaction and preferential oxidation (PROX) for the hydrogen fuel process in the combined operation PEMFC system. With the optimized methanol steam reforming condition, we tested PROX reactions in various operation temperature from 170 to 270 ℃ to investigate CO concentration data in the reformed gases. Using these different CO concentration, PEMFC performances are achieved at the combined system. Pt/C and Ru promoted Pt/C were catalysts were used for the anode to compare the stability in CO contained gases. The alloy catalyst of PtRu/C shows higher performance and better resistance to CO than the Pt/C at even high CO amount of 200 ppm, indicating a promotion not only to the activity but also to the CO tolerance. Furthermore, in a system point of view, there is a fluctuation in the PEMFC operation due to the unstable fuel supply. Therefore, we also modified the methanol reforming by a scaled up reactor and pressurization to produce steady operation of PEMFC. The optimized system with the methanol reformer and PEMFC shows a stable performance for a long time, which is providing a valuable data for the PEMFC commercialization.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.201-208
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• 2019

Recently, a fuel reforming plant for supplying high purity hydrogen is being applied to submarines. Since steam reforming is an endothermic reaction, it is necessary to continuously supply heat to the reactor. A fuel reforming plant for a submarine needs a multi-stage burner (MSB) to acquire heat and convert the combustion gas to $CO_2+H_2O$. The MSB has problems that the combustion imbalance occurs during start-up due to the temperature restriction of the combustion gas. This problems can be solved by burning $H_2O$ together with fuel and $O_2$. In this study, the simulation results of MSB were analyzed to determine the optimum flow rate of $H_2O$ supplied to the 6-stage burner. When the flow rate of $H_2O$ was low, combustion was concentrated on the burner#6 in comparison with the burner#1-#5. This combustion concentration improved as the supply amount of $H_2O$ increased. As a results, it was necessary to supply at least 4.9 kmol/h of $H_2O$ (per 1 kmol/h of fuel) to burner#1 in order to maintain the combustion gas temperature of each stage at $750^{\circ}C$ and to convert the final stage burner gas composition to $CO_2+H_2O$.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.261-268
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• 1996

Various $Cu/SiO_2$ catalysts with copper concentration ranging from 0 to 50wt% were prepared by kneading method for the steam reforming of methanol. These catalysts were calcined at temperatures in the range of $400^{\circ}C{\sim}900^{\circ}C$ and then reduced in a $H_2$ atmosphere in the range of $150^{\circ}C{\sim}350^{\circ}C$. Steam reforming of methanol was carried out at atmospheric pressure over a temperature range of $200^{\circ}C{\sim}400^{\circ}C$, steam/methanol molar ratio of 0.4~1.6 and W/F of 3~25 g.-cat.hr./mol. Characterization of the catalysts was studied using IR, BET and XRD. Using copper nitrate as a precursor for catalysts, pH in the preparation of catalysts had a great effect on the catalytic activity, but pH in the preparation of catalysts, calcination temperature, and reducing temperature in $H_2$ atmosphere had no effect on the product distribution. Optimum copper concentration, calcination temperature and reducing temperature were 40wt%, $700^{\circ}C$ and $300^{\circ}C$, respective)y. Reaction temperature for maximum $H_2$ production was $275^{\circ}C$, and the formation of methane which lowered quantity and quality of $H_2$ would be inhibited below $275^{\circ}C$. $Cu^{\circ}-Cu_2O$ might be active species in $Cu/SiO_2$ catalyst.

• Clean Technology
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• v.26 no.4
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• pp.329-335
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• 2020

Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.652-659
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• 1999

The trend of poisoning of reforming catalyst along with the position of anodic catalyst bed was studied. Keeping the conditions that steam to carbon ratio was 2.5, operating voltage was 0.75 V, current density was $140mA/cm^2$, the unit cell was operated during 24 hrs at a steady state. And then the cell was stopped, the catalysts packed in the position of inlet, middle and outlet were sampled individually and then the amount of carbon, Li and K poisoned were analysed. After 100 hrs operated, the catalysts at the same positions were analysed at the same manner. The result of this experiment was as followings. After 24 hrs operated, the poisoning amounts of Li and K in the catalyst were 0.27 wt% at inlet, 0.23 wt% at middle and the highest value 1.59 wt% at outlet. After 100 hrs, the amount of poisoning is the highest in the catalyst packed at the inlet of unit cell. The performance simulation of unit cell explained these trends of poisoning catalysts. The simulation told that the catalyst in the region of the inlet of unit cell treated the 90% of initial methane flow rate and the highest electrochemical reaction happened in this region. So the catalysts of this region were the most poisoned with carbon, Li and K and also the rate of poisoning is faster than that of the catalyst at other regions. The temperature at the region of outlet of unit cell was $30^{\circ}C$ higher than that of other regions, so more Li, and K vaporized than at other regions and little reforming reaction at this region made the catalysts poisoning rate low.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.684-687
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• 2007

Research on the solar thermal hybrid power generation technology which uses solar thermal chemical reaction has been carried out in KIER, The research covers development of solar concentration system and solar reactor for methane steam reforming reaction. This paper introduces a brief review and prospects of oversea's researches in similar areas and KIER's research progresses up to now.