• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.720-722
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• 2009

This work is mainly focused at developing the hydrogen production unit with the capacity of 20 $Nm^3/h$ of high purity hydrogen. At present steam reforming of natural gas is the preferable method to produce hydrogen at the point of production cost. The developed hydrogen production unit composed of natural gas reformer and pressure swing adsorption system. To improve the thermal efficiency of steam reforming reactor, the internal heat recuperating structure was adopted. The heat contained in reformed gas which comes out of the catalytic beds recovered by reaction feed stream. These features of design reduce the fuel consumption into burner and the heat duty of external heat exchangers, such as feed pre-heater and steam generator. The production rate of natural gas reformer was 41.7 $Nm^3/h$ as a dryreformate basis. The composition of PSA feed gas was $H_2$ 78.26%, $CO_2$ 18.49%, CO 1.43% and $CH_4$ 1.85%. The integrated production unit can produce 21.1 $Nm^3/h$ of high-purity hydrogen (99.997%). The hydrogen production efficiency of the developed unit was more than 58% as an LHV basis.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.156.1-156.1
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• 2011

It is of great importance to predict operating parameter characteristics of an integrated fuel processor by the increased life-time and system performance. In this study, computational analysis is performed to gain fundamental insights on transport phenomena and chemical reactions in reformer which consists of preheating, steam reforming, and water gas shift reaction beds. Also, a top-fired burner locates inside of the reforming system. The combustor is providing thermal energy necessary for the steam reforming bed which is a endothermic catalytic reactor. Two-dimensional numerical model of the integrated fuel processing system is introduced for the analysis of heat and mass transport phenomena as well as surface kinetics and catalytic process. A kinetic model was developed and then computational results were compared with the experimental data available in the literature. Subsequently, parameter study using the validated steam methane reforming model was conducted by considering operating parameters, i.e. steam to carbon ratio and temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.45-48
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• 2007

Thermochemical 2-step methane reforming, involving the reduction of metal oxide with methane to produce syn-gas and the oxidation of the reduced metal oxide with water to produce pure hydrogen, was investigated on ferrite-based metal oxide mediums and $WO_{3}/ZrO_{2}$. Thermochemical 2-step methane reforming were accomplished at 900 $^{\circ}C$(syn-gas production step) and 800 $^{\circ}C$(water-splitting step). In syn-gas production step, it appeared carbon deposition on metal oxides with increasing react ion time. Various mediums showed the different starting point of carbon deposition each other. To minimize the carbon deposition, the reaction time was controlled before the starting point of carbon deposition. As a result, $CO_{x}$ were not evolved in water-splitting step, Among the various metal oxides, $Mn-ferrite/ZrO_{2}$ showed high reactivity, proper $H_{2}/CO$ ratio, high selectivity of undesired $CO_{2}$ and high evolution of $H_{2}$.

• Journal of the Korean Society of Combustion
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• v.13 no.4
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• pp.47-53
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• 2008

The reaction mechanism of methane dry reforming has been investigated using an arc-jet reactor. The effects of input power, $CO_2/CH_4$ and added $O_2$ were investigated by product analysis, including CO, $H_2$, $C_{2}H_{Y}$ and $C_{3}H_{Y}$ as well as $CH_4$ and $CO_2$. In the process, input electrical power activated the reactions between $CH_4$ and $CO_2$ significantly. The increased feed ratio of the $CO_2$ to $CH_4$ in the dry reforming does not affect to the $CH_4$ conversion. but we could observe increase in CO selectivity together with decreasing $H_2$ generation. Added oxygen can also increase not only CO selectivity but also $CH_4$ conversion. However, hydrogen selectivity was decreased significantly due to a increased $H_{2}O$ formation.

• Journal of Hydrogen and New Energy
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• v.18 no.4
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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.

• Journal of Hydrogen and New Energy
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• v.14 no.1
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• pp.69-80
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• 2003

Nickel catalyst has been used for natural gas reforming with carbon dioxide, In this study, catalyst support used was HY zeolite. The optimum loading of Ni in the catalysts was 13 wt%. The effect of promoters, such as Mg, Mn, and K, was also studied. The addition of promoters to Ni catalyst improved the stability of catalysts and carbon deposition on Ni catalyst was suppressed. The reforming reactivity of promoter-added Ni catalyst was higher than that of Ni catalyst without any promoters. SEM, XRD, BET, TGA and FTIR tests were tried to characterize the catalyst structure before and after reaction.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.145-153
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• 2003

In order to develop the carbonation process as a core technology of zero emission coal power plant, study on characterization of methane steam reforming (MSR) which is main reaction of this process was carried out. The effects of gas hourly space velocity (GHSV), steam/carbon (S/C) ratio and pressure in the MSR using reforming catalyst were investigated. The equilibrium composition of the gases produced in the MSR were obtained below GHSV 7,000 hr$\^$-1/. The operating conditions of carbonation process using hybrid reaction (MSR+CO$_2$ adsorption using CaO) were 700∼800$^{\circ}C$ and S/C ratio of 2.5∼3. The equilibrium mixture of gases composed of 75∼78% H$_2$ and 8∼9％ CO$_2$ at atmospheric pressure and 60∼78% H$_2$ and 9∼l1% CO$_2$ at 1∼30 atm respectively under above operating conditions.

• Carbon letters
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• v.9 no.4
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• pp.289-293
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• 2008

Naphtha Cracking Bottom (NCB) oil was heat reformed at various reforming temperature and time, and the volatile extracts were characterized including yields, molecular weight distributions, and representative compounds. The yield of extract increased as the increase of reforming temperature ($360{\sim}420^{\circ}C)$ and time (1~4 hr). Molecular weight of the as-received NCB oil was under 200, and those of extracts were distributed in the range of 100-250, and far smaller than those of precursor pitches of 380-550. Naphtalene-based compounds were more than 70% in the as-received NCB oil, and most of them were isomers of compounds bonding functional groups, such as methyl ($CH_{3^-}$) and ethyl ($C_2H_{5^-}$). When the as-received NCB oil was reformed at $360^{\circ}C$ for 1 hr, the most prominent compound was 1,2-Butadien, 3-phenyl- (24.57%), while naphthalene became main component again as increasing the reforming temperature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.11
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• pp.942-948
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• 2007

Popular techniques for producing hydrogen 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 fur 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. Results were obtained for methane and hydrogen yields and intermediate products. The system used in this research consisted of 3 electrodes and an AC power source. In this study, air was added fur 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%, 32.6% and 35.2% respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.203-206
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• 2009

Agglomeration of catalysts is known as one of the major degradation mechanisms. Reforming of liquid fuel, which requires high temperature over $800^{\circ}C$, accelerates agglomeration of catalysts. In this work, The effects of agglomeration on catalysts activity in partial oxidation reforming conditions were investigated. Metal supported catalysts(Pt-CGO, Ru-CGO) were compared to perovskite-structured catalysts(NECS-P1, NECS-P2). High thermal stability of perovskite-structured catalysts was reported. Micro-reactor installed in electric furnace was used. its Temperature was raised from $800^{\circ}C$ to $1000^{\circ}C$ to accelerate agglomeration effect. To measure rate of agglomeration, BET analysis and CO pulse chemisorption were conducted on catalysts exposed to $1100^{\circ}C$. Metal supported catalysts showed degradation at $1000^{\circ}C$ and The rates were different according to metal supported. On the other hand perovskite-structured catalysts showed no degradation at $1000^{\circ}C$.