• Korean Journal of Materials Research
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• v.34 no.5
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• pp.254-260
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• 2024

This study is to manufacture a titanium dioxide (TiO₂) photocatalyst by recycling sludge generated using titanium tetrachloride (TiCl₄) as a coagulant. Compared to general sewage, a TiCl₄ coagulant was applied to dyeing wastewater containing a large amount of non-degradable organic compounds to evaluate its performance. Then the generated sludge was dried and fired to prepare a photocatalyst (TFS). Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and nitrogen oxide reduction experiments were conducted to analyze the surface properties and evaluate the photoactive ability of the prepared TFS. After using titanium tetrachloride (TiCl₄) as a coagulant in the dyeing wastewater, the water quality characteristics were measured at 84 mg/L of chemical oxygen demand (COD), 10 mg/L of T-N, and 0.9 mg/L of T-P to satisfy the discharge water quality standards. The surface properties of the TFS were investigated and the anatase crystal structure was observed. It was confirmed that the ratio of Ti and O, the main components of TiO₂, accounted for more than 90 %. As a result of the nitric oxide (NO) reduction experiment, 1.56 uMol of NO was reduced to confirm a removal rate of 20.60 %. This is judged to be a photocatalytic performance similar to that of the existing P-25. Therefore, by applying TiCl₄ to the dyeing wastewater, it is possible to solve the problems of the existing coagulant and to reduce the amount of carbon dioxide generated, using an eco-friendly sludge treatment method. In addition, it is believed that environmental and economic advantages can be obtained by manufacturing TiO₂ at an eco-friendly and lower cost than before.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1996.10a
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• pp.39-39
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• 1996

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.141-141
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• 2017

• Journal of Powder Materials
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• v.12 no.5 s.52
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• pp.336-344
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• 2005

In the present study, the focus is on the effect of cobalt oxide powder in the carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fine TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under flowing argon atmosphere. Changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. Titanium-cobalt-oxygen based oxide powder desalted at $600^{\circ}C$ had a mixture of $TiO_2\;and\;Co_{3}O_4$. And the one desalted at $800^{\circ}C$ had a mixture of $TiO_2\;and\;CoTiO_3$. In the case of the former powder, the reduction of cobalt oxide powder in the titanium-cobalt-oxygen based oxide powder occurred at lower temperature than the latter one. However, the carbothermal reduction of titanium dioxide powder in the titanium-cobalt-oxygen based oxide powder with a mixture of $TiO_2\;and\;Co_{3}O_4$ occurred at higher temperature than the one with a mixture of $TiO_2\;and\;CoTiO_3$. And also, the former powder showed a lower TiC formation ability than the latter one.

• Asian Journal of Atmospheric Environment
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• v.10 no.2
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• pp.99-113
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• 2016

In order to improve the portability of basic absorbents monoethanolamine (MEA) and glycine (Gly), both were supported on microporous activated carbon (AC). Chemical modification by alkali-metal ion exchange (of Li, Na, K) was carried out on Gly-based absorbents. All supported absorbents were subjected to $CO_2$ absorption capacity (pure $CO_2$) and selectivity (indoor level) tests. Textural and chemical characterizations were carried out on test sorbents. All impregnation brought about significant reduction of specific surface area and microporosity of the adsorbent Depreciation in the textural properties was found to result to reduction in pure $CO_2$ sorption. Contrarily, low-level $CO_2$ removal capacity was enhanced as the absorbent dosage increases, resulting in supported 5 molar MEA in methanol solution. Adsorption capacities were improved from 0.016 and 0.8 in raw ACs to 1.065 mmol/g for MEA's. Surface chemistry via X-ray photoelectron spectroscopy (XPS) of the supported sorbents showed the presence of amine, pyrrole and quaternary-N. In reducing sequence of potency, pyridine, amine and pyrrolic-N were noticed to contribute significantly to $CO_2$ selective adsorption. Furthermore, the adsorption isotherm study confirms the presence of various SNGs heterogeneously distributed on AC. The adsorption mechanism of the present AC adsorbents favored Freundlich and Langmuir isotherm at lower and higher $CO_2$ concentrations respectively.

• Plant Journal
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• v.9 no.2
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• pp.42-45
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• 2013

The worldwide issue of greenhouse gas reduction has recently drawn great attention to carbon capture and storage(CCS). In this study, we developed a 10,000 ton/year pilot injection plant for geological storage of carbon dioxide. Major components of the pilot plant include a pressure pump, a booster pump, and an inline heater to bring liquid carbon dioxide into its supercritical state. The test results show that the pilot plant readily achieves the injection pressure and temperature, showing satisfactory control performance. The overall power consumption is 2,000 ~ 2,500 W, more than 75% of which consumed by the pressure pump. This study will facilitate varied research on greenhouse gas reduction as the only domestically developed system for geological injection.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.733-741
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• 2021

Globally, in accordance with the goals set forth in the 2015 Paris Climate Agreement, each country has established and declared a reduction target for carbon neutrality by 2050. The roadmaps for establishing long-term greenhouse gas emissions development strategies and setting reduction targets have been announced. As the international community accelerates the transition to the net-zero society, 128 countries have declared net-zero by the end of 2020, and the net-zero declaration continues to expand around G20 member states. In December 2020, Korea announced the "2050 Net-zero Strategy" to establish a foundation for simultaneously achieving carbon reduction, economic growth, and improved quality of life for the people through active response to the net-zero, and pursuing policy tasks in stages to do this. Comprehensive carbon management is insufficient due to the lack of comprehensive carbon management due to the departure from the areas of mandatory reduction, such as the GHG energy target management system and the GHG emissions trading offset system implemented to reduce greenhouse gases in Korea. Currently, there is no cases for estimation or calculation of carbon dioxide emissions for the Mine Reclamation projects. It is reviewed the standard methods proposed by domestic and foreign carbon emission calculation methods and proposed appropriate carbon emission estimation methods for the Mine Reclamation projects in this study.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.598-603
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• 2005

Biogas produced from anaerobic digestion processes has about 60% of methane and about 40% of carbon dioxide. Raw biogas can be used in internal combustion engines either spark ignition or diesel engines. Since the gas has relatively low calorific values, engine power also is lower than rated power values. Modified engines or biogas-specific engines have been utilized in order to increase efficiency. Another option is gas cleansing for increasing its calorific values. A couple of European countries adopted this approach in using biogas for one of transportation fuels, such as $CO_2$ scrubbing with water or special solutions. This study reports the results of water scrubbing for reducing $CO_2$ concentration. In 2.5m-high PVC pipe accepting water, $CO_2$ reduction rates were investigated. When flow rate of $CO_2$ and air mixture was about 5 LPM, $CO_2$ concentration was decreased up to 70%. Higher calorific biogas through water scrubbing is expected to be applied to various commercial engines without costly modification.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1083-1087
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• 1997

Every effort is now being exerted in industrialized and developing countries to reduce emission of greenhouse gases from electric power sector. In this paper, we provide supply-side resource mix strategies in the long-term generation expansion planning under the expected greenhouse gas regulations. Under the environmental regulations, we explore the least-cost generation expansion plan of Korea and determine the composition of future resource mixes. Our analysis is performed on the basis of the revised WASP package which can evaluate emission of carbon dioxide from each power plant. The evaluation process of carbon dioxide emissions, which can consider the efficiency and operating conditions of each generator simultaneously, has been incorporated into the probabilistic production cost simulation module of WASP.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.68-74
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• 1995

The optimum conditions was synthesized for the formation of Magnetite ($Fe_3O_4$) by air bubbling with the suspensions obtained by mixing Ferrous sulfate ($FeSO_4\cdot 7H_2O$) and Sodium Hydroxide (NaOH) solution in various values equivalent ratio($R=2NaOH/FeSO_4$) were studied. The changes of the structure were measured with XRD, $EM and BET. Equivalent ratio R: 0.65 was synthesized Goethite ($\alpha$-FeOOH), which becomes Maghemite ($\gamma=Fe_2O_3$) by dehydration, reduction and oxidation process. At the equivalent ratio over 1 (R>1), Magnetite ($Fe_3O_4$) was synthesized directly. The oxygen-deficient Magnetite ($Fe_3O_{4-\delta}$), which is obtained by flowing $H_2$ gas(100 ml/min) through the synthesis Magnetite at 350$\circ$C for 4 hr. By using it, was researched the decomposition reaction of $CO_2$. $CO_2$ was decomposed nearly 100% in 45 minutes by the oxygen-deficient Magnetite.