• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.478-485
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• 2022

The certification performance issued through an external business is sold to companies subject to the emission trading system allocation, and the company subject to the allocation can secure the quota by converting the purchased external business certification performance into offset credits. In this methodology, when fossil fuels that used existing oil boilers (by oil type) were replaced with boilers using propane gas with a relatively low carbon content, the amount of carbon dioxide emission reduction by oil type was recognized. As an initial analysis to make up for the insufficient quota of large corporations, the amount of carbon reduction emissions and emission rights trading was calculated.

• Journal of the Korean Society of Safety
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• v.38 no.6
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• pp.9-15
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• 2023

Hydrogen is gaining attention as a sustainable and renewable energy source, potentially replacing fossil fuels. Its high diffusivity, wide flammable range, and low ignition energy make it prone to ignition even with minimal friction, potentially leading to fire and explosion risks. Workplaces manage ignition risks by classifying areas with explosive atmospheres. However, the effective installation of a blast wall can significantly limit the spread of hydrogen, thereby enhancing workplace safety. To optimize the wall installation of this barrier, we employed the response surface methodology (RSM), considering variables such as wall distance, height, and width. We performed 17 simulations using the Box-Behnken design, conducted using FLACS software. This process yielded two objective functions: explosion likelihood near the barrier and explosion overpressure affecting the blast wall. We successfully achieved the optimal solution using multi-objective optimization for these two functions. We validated the optimal solution through verification simulations to ensure reliability, maintaining a margin of error of 5%. We anticipated that this method would efficiently determine the most effective installation of a blast wall while enhancing workplace safety.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.25-30
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• 1993

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were $SiO_2(68.74\%),\;Al_2O_3(18.40\%),\;CaO(0.42\%),\;MgO(1.04\%)\;and\;K_2O(2.26\%)$ in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.4
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• pp.229-239
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• 1992

A receptor model application was performed by using a chemical mass balance (CMB) model to identify and apportion the specific source of airborne organic pollutants, particularly polynuclear aromatic hydrocarbons (PAHs). Source profiles of PAHs produced from the combustion of fossil fuels for CMB modeling were prepared by measuring them in emission gases. The emission sources which were examineed for the development of PAH source profiles are a coal-fired furnace using Yontan, a bunker-C iol heating boiler, and gasoline-and diesel engine automobiles. The ambient concentrations of PAHs were determined at four sites in Daejon city in 1991 with a seasonal variation. Wintertime air samples contained more extractable organic matter than summertime samples. The results of CMB modeling were various depending on the sampling sites and seasons, but the emission from bunker-C oil heating boliers was the predominant factor to affect local air quality throughout the year.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.647-650
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• 2003

In anhydrous organic solvents, the complexes formed between AOT (dodecylbenzene sulfuric acid sodium salt) and hemoproteins, such as hemoglobin, myoglobin, or cytochrome c, displayed remarkably higher activity than the hemoprotein powders to oxidize dibenzothiophene, a model compound of organic sulfurs contained in fossil fuels. In slightly hydrophobic organic solvents, such as ethyl acetate and butyl acetate, dibenzothiophene was completely oxidized catalytically by the cytochrome c-AOT complex with cumene hydroperoxide (${\alpha},{\alpha}-dimethylbenzyl$ hydroperoxide) as an oxidant. In highly hydrophobic organic solvents, such as decane and hexadecane, however, the activity of the cytochrome c-AOT complex decreased, presumably due to the aggregation of the hemoprotein-AOT complex in these solvents.

• Journal of the Korean Chemical Society
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• v.7 no.1
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• pp.38-41
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• 1963

Nb is one of the trouble-some fission products in the reprocessing of nuclear fuels. In this paper, the extraction of Nb from 1, 2, 3, 4, 6 and 9N $HNO_3$ solution by mixtures of TBP and DBP in dodecane are reported. Sums of the concentration of TBP and DBP are kept to 20%. When the concentrations of DBP are lower the $2{\times}10^{-2}%$, distribution ratios are almost same, and ratios increase abruptly and the slope is about 2.5 at between $2{\times}10^{-2}$ to $4{\times}10^{-1}%$, then slope falls down to about 0.5. There is aging effect on mixture of TBP and DBP.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.86-91
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• 2005

A metal product obtained from an electrolytic reduction process, possesses less volume and radioactivity than those of the unprocessed spent oxide fuels. The chemical composition of the metal product varies according to the process condition. In this work, a basic study was performed to evaluate the chemical forms of the spent oxide fuel components in an electrolytic reduction process with the operation conditions. One of the most important operation conditions is the cell potential applied for the reduction cell. It is expected that $PU_{2}O_3$ is difficult to reduce even though the cell potential is negative enough to reduce the lithium oxide when the activity of $Li_{2}O$ exceeds 0.003. The reduction of actinide oxides via the reduction of $Li_{2}O$ is assumed to have a greater reduction yield than a direct reduction of the actinide oxides.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.214-220
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• 2015

Since resources of fossil fuels are limited, development of alternative energies is emphasized and research on new-regenerative energy is actively in progress worldwide. In present research, physical and chemical characteristics of mixed fuel are analyzed in detail for the different mixture rate of conventional and bio-diesel and ultrasonic irradiation time. Experimental setup consists of ultrasonic generator, vibrator, horn, and reflector. Various physical and chemical characteristics of fuel are investigated for volumetric mixture rate of bio-diesel from 0 to 100%. As results, viscosity and surface tension is increased as mixture rate of bio-diesel is increased. Also, molecular splits and reunions are increased and decreased repeatedly after some period of time as ultrasonic energy irradiation time is increased. As conclusion of experiments, Olefin rate, Branch index, and Aromatic rate are influenced by ultrasonic irradiation time.

• Journal of the Korean Chemical Society
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• v.44 no.5
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• pp.480-484
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• 2000

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.1-6
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• 2013

The ionic liquids are known to potential alternative solvents capable of replacing the commercial solvents in various processes including those in nuclear fuel cycle. As to the material, a number of studies have already reviewed the interesting results and addressed the spectroscopic as well as electrochemical behaviors of metal elements included in spent nuclear fuels. It has found that the important properties of metal ions in TBP dissolved ILs have led the development of alternative technologies to traditional solvent extraction processes. On the other hand, the electrochemical deposition of metal ions in ILs have been investigated for the application of the solvents to aqueous as well as to non-aqueous processes. In this work, a review on the application of ILs in nuclear fuel cycle is briefly presented to understand the notable researches on ILs focusing on aqueous processes.