• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.6
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• pp.641-648
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• 2011

Off-gases emitted from the anode of a molten carbonate fuel cell (MCFC) at high temperatures for power generation are used as fuel in catalytic combustion. The heat generated in the catalytic combustor is utilized as the heat for the endothermic reaction required for steam reforming. Among the various operational conditions of the integrated reactor, we varied the inlet gas compositions of the catalytic combustor according to fuel utilization in the MCFC and the ratio of steam to carbon in the reformer. Subsequently, the thermal behaviors and reaction characteristics of the integrated reactor were investigated experimentally. The fundamental data from this experimental study will be useful for the design and fabrication of a more practical integrated reactor in the future.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.20-25
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• 2017

For the HCNG bus using fuel which is the mixture gas of hydrogen and natural gas, the fuel efficiency and $CO_2$ emission characteristics were analyzed based on the WHVC test results and compared with that of the CNG and diesel buses. $CO_2$ emission characteristics were also analyzed by contribution effects such as carbon emission factor and fuel consumption. As a result, the fuel economy of HCNG bus was evaluated to be 11.5% improvement compared to CNG bus, and it was also showed equivalent to diesel bus. In addition, the $CO_2$ emission of HCNG bus was reduced 20.4% and 34.5% compared to CNG bus and diesel bus respectively. It was concluded that the $CO_2$ emission characteristics were influenced by the carbon emission factor depending on fuel composition and the fuel consumption according to the engine performance.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.769-774
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• 2011

Porous carbon nanofibers(CNF) were synthesized via NaOH activation at 700~$900^{\circ}C$, and the porous CNF-supported PtRu catalysts were evaluated for the anode in direct methanol fuel cells. The change of surface characteristics by NaOH activation was examined by analyses of the specific surface area and pore size distribution. The morphological and structural modification was investigated under scanning electron microscopy. The activity of catalysts supported on porous CNFs was examined by cyclic voltammograms and single cell tests. The pore formation on CNF by the NaOH activation was discussed, concerning the catalyst activity, when they were applied as catalyst supports.

• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.513-520
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• 2012

The electrochemical reaction of refuse derived fuel (RDF) and refuse plastic/paper fuel (RPF) was investigated in the direct carbon fuel cell (DCFC) system. The open circuit voltage (OCV) of RPF was higher than RDF and other coals because of its thermal reactive characteristic under carbon dioxide. The thermal reactivity of fuels was investigated by thermogravimetric analysis method. and the reaction rate of RPF was higher than other fuels. The behavior of all sample's potential was analogous in the beginning region of electrochemical reactions due to similar functional groups on the surface of fuels analyzed by X-ray Photoelectron Spectroscopy experiments. The potential level of RDF and RPF decreased rapidly comparing to coals in the next of the electrochemical reaction because the surface area and pore volume investigated by nitrogen gas adsorption tests were smaller than coals. This characteristic signifies the contact surface between electrolyte and fuel is restricted. The potential of fuels was maintained to the high current density region over 40 $mA/cm^2$ by total carbon component. The maximum power density of RDF and RPF reached up to 45~70% comparing to coal. The obvious improvement of maximum power density by increasing operating temperature was observed in both refuse fuels.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.371-376
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• 2012

The experimental test was conducted for a heavy-duty DME bus in JE-05 exhaust gas test mode using a chassis dynamometer, exhaust gas analyzers, and a PM measurement system. The heavy-duty DME bus was not equipped with after-treatment systems such as DOC or DPF. The dynamic behavior, emission characteristics, and fuel economy of the bus were investigated with an 8.0-liter, 6-cylinder conventional diesel engine. The results showed that the dynamic behavior in DME mode was almost the same as in diesel mode. However, there was little difference among the two operation modes for $NO_x$ and CO emissions. THC emissions were lower for DME mode than for diesel mode. Also, the amount of PM emissions was remarkably lower than for the diesel mode because DME contains a greater amount of oxygen than diesel. The data showed that $CO_2$ emissions were almost similar in the two modes but fuel economy (calculated using heating value) was lower for DME mode than for diesel mode.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.657-666
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• 2022

The International Maritime Organization(IMO) recommends the active implementation of national policies on technological development and energy efficiency to reduce Green House Gas (GHG) in the international shipping sector. Such IMO environmental regulation policies have a great impact on the entire shipping sector and are also a heavy burden on ship's owners. The most reasonable way to curb GHG emissions from ships comes down to the development of zero-emission ships. In other words, the development of a fuel cell ship (FCS) driven by an eco-friendly fuel is an alternative that can escape the IMO regulations. Countries in Asia, Northern America, and Europe independently develop and produce PEMFC, and are pursuing international standardization by acquiring approval in principle from an internationally accredited registration authority. Currently, there are three types of fuel cells (FC) that are recommended for ships: a Polymer Electrolyte Membrane Fuel Cell (PEMFC), a Molten Carbonate Fuel Cell (MCFC), and a Solid Oxide Fuel Cell (SOFC). In this study, PEMFC, which is expected to grow continuously in the global FC market, was analyzed domestic and international development trends, specifications, performance, and empirical cases applied to ships. In addition, when applying PEMFC to ships, it was intended to suggest matters to be considered and the development direction.

• Clean Technology
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• v.28 no.2
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• pp.174-181
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• 2022

Biomass is a sustainable alternative resource for production of liquid fuels and organic compounds that are currently produced from fossil fuels including petroleum, natural gas, and coal. Because the use of fossil fuels can increase the production of greenhouse gases, the use of carbon-neutral biomass can contribute to the reduction of global warming. Although biological and chemical processes have been proposed to produce petroleum-replacing chemicals and fuels from biomass feedstocks, it is difficult to replace completely fossil fuels because of the high oxygen content of biomass. Production of petroleum-like fuels and chemicals from biomass requires the removal of oxygen atoms or conversion of the oxygen functionalities present in biomass derivatives, which can be achieved by catalytic hydrodeoxygenation. Hydrodeoxygenation has been used to convert raw biomass-derived materials, such as biomass pyrolysis oils and lignocellulose-derived chemicals and lipids, into deoxygenated fuels and chemicals. Multifunctional catalysts composed of noble metals and transition metals supported on high surface area metal oxides and carbons, usually selected as supports of heterogeneous catalysts, have been used as efficient hydrodeoxygenation catalysts. In this review, the catalysts proposed in the literature are surveyed and hydrodeoxygenation reaction systems using these catalysts are discussed. Based on the hydrodeoxygenation methods reported in the literature, an insight for feasible hydrodeoxygenation process development is also presented.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.41-51
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• 2023

As abnormal climatic event occur frequently due to global warming, many nations have proclaimed their commitment to achieving carbon neutrality and are actively pursuing a transition toward a hydrogen economy. At this time, ammonia has garnered significant attention not only as a high-capacity hydrogen carrier but also as a promising candidate as a carbon-free fuel. In particular, anion exchange membrane fuel cells offer the advantage of directly supplying ammonia to the fuel cell, eliminating the necessity for separate ammonia decomposition or hydrogen purification. Therefore, in this study, the operation principle and research trend of the anion exchange membrane fuel cell are reviewed, and several research using ammonia as a fuel in anion exchange membrane fuel cell are also investigated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.768-773
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• 2014

In this study, experimental and numerical studies for the synthesis of carbon nanotube(CNT) in methane counterflow diffusion flame have been performed. Methane mixed with acetylene($C_2H_2$) was used as a fuel gas and ferrocene was used as a catalyst for synthesis of CNT. The major parameters was $C_2H_2$ mixing rate and mixing rates were 2 %, 6 %, and 10 %. Characteristics of CNT formation on grid were analyzed from SEM images. the chemical reaction mechanism adopted is GRI-MECH 3.0. Numerical results showed that flame temperature and CO mole fraction were increased with increasing acetylene mixing rate. Experimental results showed that the CNT synthesis in 2% acetylene mixture flame better than that of 6% and 10% acetylene mixture flames. It can be considered that 6% and 10% acetylene mixture flames generated the excessive carbon source and then it interrupted the supplement of the carbon source into ferrocene catalyst. It can be found that the supply of appropriate quantity of carbon source can make effect to synthesis of high purity of CNT.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.3
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• pp.133-140
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• 2010

Carbon fiber has many potential applications in a wide array of fields of solar cell, fuel cell, batteries, and polymer matrix composites due to an exceptional mechanical properties and chemical stability. In this study, the effects of catalysts on the property of carbon nanostructures grown on the carbon fiber were systematically investigated. The surface treatment of carbon fiber and catalysts synthesis for carbon nanostructures growth were carried out by one-pot ELP method and thermal CVD, respectively. The surface morphology and crystal structure of carbon nanostructures were examined using a field emission scanning electron microscope and transmission electron microscope. Depending on the type of catalysts and the molar ratio, various types of carbon nanostructures like carbon nanotube, carbon nanofilament, carbon nanospring and etc. were synthesized on the surface of carbon fibers surface.