• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.494-502
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• 2016

A 1-dimensional heterogeneous reactor model with the gas-solid interfacial phase gradients was developed for the simulation of the packed bed reactor where the exothermic reversible water gas shift reaction for the natural gas steam reformed gas was proceeding in adiabatic mode. Experimental results obtained over the WGS catalyst, C18-HA, were best simulated when the frequency factor of the reaction rate constant was adjusted to a half the value reported over another WGS catalyst, EX-2248, having the same kinds of active components as the C18-HA. For the reactor of the inside diameter 158.4 mm and the bed length 650 mm, the optimum feeding temperature of the reformed gas was simulated to be $194^{\circ}C$, giving the lowest CO content in the product gas by 1.68 mol% on the basis of dried gas. For reactors more extended in the bed length, the possible lowest CO content in the product gas with the optimum feeding temperature of the reformed gas were suggested.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.9
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• pp.652-658
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• 2008

Design performances of the fuel cell / gas turbine hybrid power generation systems based on two different fuel cells (PEMFC, SOFC) have been comparatively analyzed. In each system, the fuel cell operates at an elevated pressure corresponding to the compressed air pressure of the gas turbine. Both internally and externally reformed systems were analyzed for the SOFC hybrid system. Component design parameters of 10kW class small systems are assumed. For all hybrid systems, increasing the turbine inlet temperature increases the power portion of the gas turbine. With increasing the turbine inlet temperature, system efficiency decreases in the PEMFC system and the internally reformed SOFC system while that of the externally reformed SOFC system increases slightly. The internally reformed SOFC hybrid system is predicted to exhibit the best system efficiency.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.189-192
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• 2015

An experimental study was conducted to find the effect of DBD plasma on the flammability limits of inert-gas-diluted fuel. The results showed that the concentration of diluting nitrogen at flammability limit increased when nitrogen-diluted methane and propane were reformed by plasma, while it decreased when nitrogen-diluted ethylene was reformed by plasma. Gas chromatography results suggested that the fuel type dependence of flammability limits is due to the difference in the concentrations of hydrogen and hydrocarbon species in reformed fuel.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.628-635
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• 2016

Natural gas reformed hydrogen is used as a fuel of fuel cell vehicle, PSA process is used for the purification of reformed hydrogen. In this study, the performance of CO adsorbent in PSA process was evaluated. Zeolite adsorbents used in the commercial PSA process is used. The physical and chemical properties of adsorbents were characterized using BET apparatus, XRD, and FE-SEM. The breakthrough apparatus modified from GC was used for the CO breakthrough experiment, the quantitative analysis of CO adsorption capacity was performed using CO breakthrough curve. Zeolite 10X and 13X showed superior CO adsorption capacity than activated alumina. The CO adsorption capacity of zeolite 10X is more than twice of zeolite 13X even the BET surface area is low. It seems that the presence of $Ca^{2+}$ cation in zeolite 10X is beneficial to the adsorption of CO.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.46-52
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• 2009

Hydrogen can extend the lean misfire limit to a large extent when it is mixed with conventional fuels for an internal combustion engine. This study is about fuel reforming to produce hydrogen enriched gas as a fuel for engine. Especially gasoline, which consists of numerous hydrocarbon fuels, considered as source of reformed gas. Various hydrocarbons, including commercial fuel were reformed and potentialities of reformed gas on vehicles were accessed. The reforming efficiency and hydrogen yield were observed. Maximum hydrogen yield were found with different gas hourly space velocity(GHSV) and O2/C ratio of reforming conditions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.639-643
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• 2009

A reformer, which produces hydrogen from natural gas, plays a major role for producing quality hydrogen to fuel-cell system. In this paper, fuel processor is designed to deliver hydrogen(75%) from the reformer to 200W fuel-cell system, and the electrical output power of the fuel-cells is examined by being injected different hydrogen concentrations to the system. We verified that the output power characteristics of the fuel-cells with 75% reformed hydrogen was lower about 7% than the case of pure hydrogen supplied. The type of reformer in this experiment takes SMR(Steam methane reforming) process, and the temperature variation characteristics of reforming process by reactions are examined in operation.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.20-23
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• 2008

The current gas regulations have been reformed into a new technical standards system called as "KGS (Korea Gas Safety) Code" system. Korea Gas Safety Corporation has developed a new framework of technical standards classification method and will manage the new technical standards system in compliance with the mandatory requirements of gas regulations. This study will cover an overall view of the reformation and show "KGS Code" in detail.

• Environmental Engineering Research
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• v.13 no.4
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• pp.192-196
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• 2008

The generation of high purity hydrogen from reformed hydrocarbon fuels, or syngas, is essential for efficient operation of the fuel cell (PEMFC, Polymer Electrolyte Membrane Fuel Cell). Usually, major components of reformed gas are $H_2$, CO, $CO_2$ and $H_2O$. Especially a major component, CO poisons the electrode of fuel cells. The water gas shifter (WGS) that shifts CO to $CO_2$ and simultaneously produces $H_2$, was developed to a two stage catalytic conversion process involving a high temperature shifter (HTS) and a low temperature shifter (LTS). Also, experiments were carried out to reduce the carbon monoxide up to $3{\sim}4%$ in the HTS and lower than 5,000 ppm via the LTS.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.170-177
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• 2006

Hydrogen can extend the lean misfire limit to a large extent when it is mixed with conventional fuels for a spark ignition engine. In this study, hydrogen-enriched gaseous fuels by reforming process were simulated according to their proportions of $H_2$, CO, $CO_2$ and $N_2$ gases. Pure hydrogen and two different hydrogen-enriched gaseous mixtures(A-, B-composition) were tested for their basic effects on the engine performances and emissions in a single cylinder research engine. A- and B-composition showed different results from 100% $H_2$ addition because air/fuel mixtures were more diluted by their additions. Even though the energy fraction of reformed gases was increased, combustion stabilities and lean misfire limits were not sensitively improved. It means that combustion augmentation by $H_2$ addition was offset by the charge dilution of $N_2$ and $CO_2$. In addition, the low flammability of CO gas deteriorated thermal efficiencies. CO emission was drastically increased with B-composition which included higher CO component. However, $NO_x$ was reduced as energy fraction($X_e$) rised except for the case of 100% $H_2$ addition at $\lambda=1.2$ and was, for A-composition, lowered to a factor of ten when compared with that of $H_2$ addition. HC emissions were largely influenced by $COV_{imep}$ due to misfire and partial burns.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.73-82
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• 2012

A 2-dimensional heterogeneous reactor model was developed and simulated for a tube reactor of packed bed where the steam-$CO_2$ combined reforming reaction of natural gas proceeded to produce synthesis gas. Under the reactor feeding rate, 45 $Nm^3$/h, of the reactant gas stream, the 2-dimensional heterogeneous reactor model showed the similar results to those from the ASPEN simulator although there were some discrepancies between the two in the temperature and the $H_2$/CO ratio of the reformed gas at the reactor exit. The calculated enthalpy difference between the reformed gas at the reactor exit and the reactant gas fed to the reactor was closely correspondent to the total amount of heat transferred to the reactor interior from the furnace. This supports that the 2-dimensional heterogeneous reactor model was reasonably established and the numerical solution was properly obtained.