• 한국가스학회:학술대회논문집
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• 2003.05a
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• pp.252-255
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• 2003

• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.204-208
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• 2014

This study investigated the effect of hydrogen permeance and selectivity, catalyst amount, $H_2O/CO$ ratio in a feed stream, and Ar sweep gas on the performance of a water gas shift reaction in a membrane reactor. It was observed that a minimum hydrogen selectivity of 100 was needed in a membrane reactor to obtain a hydrogen yield higher than the one at equilibrium and the hydrogen yield enhancement gradually decreased as the hydrogen permeance increased. The CO conversion in a membrane reactor initially increased with the catalyst amount and reached a plateau later for a membrane reactor with a low hydrogen permeance while the high CO conversion independent of a catalyst amount was observed for a membrane reactor with a high hydrogen permeance. For the $H_2O/CO$ ratio in a feed stream higher than 1.5, a hydrogen permeance had little effect on the CO conversion in a membrane reactor and it was found that a minimum Ar molar flow rate of $6.7{\times}10^{-6}mol\;s^{-1}$ was needed to achieve the CO conversion higher than the one at equilibrium in a membrane reactor.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.528-532
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• 2007

The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of $H_2$, CO, $CO_2$ and $H_2O$(steam) followed by water gas shift(WGS) and CO clean-up steps. The WGS reaction that shifts CO to $CO_2$ and simultaneously produces another mole of $H_2$ was carried out in a two-stage catalytic conversion process involving a high temperature shift(HTS) and a low temperature shift(LTS). In the WGS operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about $3\sim4%$ followed to about 0.5% via a low temperature shift catalyst. The WGS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to less than 0.5%.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.474-480
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• 2011

Hydrocarbon is required to be converted to pure hydrogen without carbon monooxide (CO) for polymer exchange membran fuel cell (PEMFC) applications. In this paper, CO cleaning processes as the downstream of Dimethyl ehter (DME) autothermal reforming process were performed in micro-reactors. Our study suggested two kinds of water gas shift (WGS) reaction process: High Temperature shift (HTS) - Low Temperature shift (LTS), Middle temperature shift (MTS). Firstly, using perovskite catalyst for MTS was decreased effieiciency since methanation. Using HTS-LTS the CO concentration was decreased about 2% ($N_2$ & $H_2O$ free) with the reaction temperature of $420^{\circ}C$ and $235^{\circ}C$ for HTS and LTS, respectively. As the final stage of CO cleaning process, preferential oxidation (PROX) was applied. The amount of additional oxygen need 2 times of stoichiometric at $65^{\circ}C$. The total conversion reforming efficiency of 75% was gained.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.21-27
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• 2011

The comparison work was conducted for the methanol steam reforming among commercial Cu-based catalysts, viz. ICI-M45, which is for the methanol synthesis, MDC-3 and MDC-7, which are for the water-gas shift reaction. The catalytic activity for the water-gas shift reaction was also compared over three catalysts. Among them, MDC-7 showed the highest methanol conversion and formation rate of hydrogen and carbon dioxide at 473 K for the methanol steam reforming. To find out any promotional effect between ICI-M45 and MDC-7, three different packing methods with these two catalysts were examined. However, no synergistic effect was observed. The catalytic activity for watergas shift reaction decreased in the following order: MDC-7 > MDC-3 > ICI-M45. The highest activity of MDC-7 for the methanol steam reforming as well as the water-gas shift reaction can be due to its high surface area, copper dispersion, and an adequate Cu/Zn ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.317-319
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• 2000

We fabricated the QCM with Langmuir-Blodgett(LB) film deposited at the different subphase pH and investigated the resonant frequency response by the injection of organic gas response. In the $\pi$-A isotherms, the monolayer on the air/water interface had different limiting area per molecule and showed more condensed status as increasing the subphase pH. When palmitic acid LB film was deposited on the QCM, the resonant frequency shift was proportional to the deposited layer and had more resonant frequency shift in the case of the higher pH range as expected. In the resonant frequency for the injection of organic gas, it has been improved in the case of LB film fabricated at the lower subphase pH range and dependant upon the molecular weight of organic gas.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.331-343
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• 2005

Development of hydrogen station system is an important technology to commercialize fuel cells and fuel cell powered vehicles. Generally, hydrogen station consists of hydrogen production process including desulfurizer, reformer, water gas shift (WGS) reactor and pressure swing adsorption (PSA) apparatus, and post-treatment process including compressor, storage and distributer. In this review, we investigate the R&D trends and prospects of hydrogen station in domestic and foreign countries for opening the hydrogen economy society. Indeed, the reforming of fossil fuels for hydrogen production will be essential technology until the ultimate process that may be water hydrolysis using renewable energy source such as solar energy, wind force etc, will be commercialized in the future. Hence, we also review the research trends on unit technologies such as the desulfurization, reforming reaction of fossil fuels, water gas shift reaction and hydrogen separation for hydrogen station applications.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.6
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• pp.577-585
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• 2014

Nanorod and particle shape $CeO_2$ were synthesized via hydrothermal process and precipitation method, respectively, and used as supports of Pt catalyst for water gas shift (WGS) reaction. Three different durations (12, 48, and 96h) for hydrothermal process were applied for the preparation of nanorod type $CeO_2$. 1.0 wt% of Pt was loaded on the prepared supports with incipient wetness method prior to the catalytic activity tests that were carried out at a GHSV of $95,541h^{-1}$, and a temperature range of 200 to $360^{\circ}C$. Varying duration of hydrothermal process led to the difference in physical characteristics of $CeO_2$ nanorods, such as aspect ratio, BET surface area, pore diameter, and pore volume. Consequently, the catalytic activities of Pt/$CeO_2$ nanorods were affected by the physical characteristics of the supports and appeared to be in the order of Pt/$CeO_2$(12) > Pt/$CeO_2$(48) > Pt/$CeO_2$(96). The comparison of the catalytic activities and results of the analysis (XPS, XRD, SEM, BET and TPR) for the supports revealed that the activity of the catalysts depends on chemical states of the Pt and the support materials in the temperature range that is lower than $280^{\circ}C$. However, the activity is rather dependent on the physical characteristic of the supports because the increased gas velocity limits the mass transfer of reactants in micropores of the supports.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2228-2231
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• 2007

Water gas shift reactor in fuel processing is an important part that converts carbon monoxide into hydrogen. Fuel processing system for PEMFC usually has two stages of WGS reactors, which are high temperature and low temperature shifter. In this study we prepared noble metal catalysts and compared their performances with that of a commercial iron chromium oxide catalyst. Noble metal catalysts and the commercial catalyst showed quite different temperature dependence of carbon monoxide conversion. The conversion of carbon monoxide at the commercial catalyst was very low at medium temperature(${\sim}300^{\circ}C$) and increased rapidly as temperature increased while the conversion at noble metal catalysts was high in the medium temperature range and decreased as temperature increased, which is thermodynamically expected. Their characteristics agreed well with the literature published, and we are accomplishing further study for improvement of the noble metal catalysts.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.54-60
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• 1962

The water gas shift conversion catalyst prepared by the American Cyanamide Co. was subjected to fluidization in a 2-in. Pyrex glass tube to obtain the basic fluidization characteristic data. The size of the catalyst charged ranged from 70 to 120 meshes and it was supported on a single layer 300-mesh wire gauze through which the fluidizing medium, the air, was passed. Following are some data and facts found by the authors: (1) The catalyst particles were porous, and their surfaces were trough and irregular. (2) The average effective particle density and the average shape factor of these particles were 152.2 lb/$ft^3$ and 0.865 respectively. (3) As the particle diameter of the catalyst increased, the minimum fluid voidage of the bed decreased slightly. (4) Just before the incipient fluidization, pressure drop suddenly fell and the bed expanded simultaneously. (5) After fluidization set in, the expansion characteristics of the catalyst bed were similar to those of sand and glass beads except intense bubbling in the catalyst bed.