• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.555-561
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• 2011

The objective of this study is the development of carbon recycle technology which converts $CO_2$ captured from flue gas to CO or carbon and reuse in industrial fields. Since $CO_2$ is very stable and difficult to decompose, metal oxide was used as an activation agent for the decomposition of $CO_2$ at low temperature. Metal oxides which convert $CO_2$ to CO or carbon at $500^{\circ}C$ were prepared using Zn-ferrite by the solid state reaction and hydrothermal synthesis. The behaviors of $CO_2$ decomposition were studied using temperature programmed reduction/oxidation (TPR/TPO) and thermogravimetric analyzer (TGA). Zn-ferrite containing 5 wt% ZnO showed the largest reduction and oxidation. Reduction by $H_2$ was 26.53 wt%, oxidation by $CO_2$ was 25.73 wt% and 96.98% of adsorbed $CO_2$ was decomposed to $CO_2$ and carbon with excellent oxidation-reduction behaviors.

• Analytical Science and Technology
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• v.11 no.6
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• pp.460-468
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• 1998

Schiff base ligands such as $SOPDH_2$, $SNDH_2$, $EBNH_2$, and $PBNH_2$ and their Co(II) complexes such as [$Co(II)(SND)(H_2O)_2$], [$Co(II)(SOPD)(H_2O)_2$], [$Co(II)(EBN)(H_2O)$], and [$Co(II)(PBN)(H_2O)$] have been synthesized. The mole ratio of Shiff base ligand to cobalt(II) for the Co(II) complexes was found to be 1:1. Also these complexes have been configurated with hexa-coordination. Reduction of dioxygen was investigated by cyclic voltammetry at glassy carbon electrodes modified with Schiff base Co(II) complexes in 1 M KOH aqueous solution. At modified glassy carbon electrode with Schiff base Co(II) complexes, reduction peak current of oxygen was increased and peak potential was shifted to more positive direction compared to bare glassy carbon electrode. The electrokinetic parameters such as number of electron and exchange rate constant were calculated from the results of cyclic voltammogrms. The reduction of dioxygen at glassy carbon electrode has been $2e^-$ reaction pathway. Exchange rate constant at glassy carbon electrode modified with Co(II) complexes was increased 2~10 times compared to bare electrode.

• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.409-415
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• 2012

Post-kyoto regime has been discussing with the GHG reduction commitment. GHG energy target management system also has been applied for the domestic measures in the country. Universities are major emission sources for GHG. It is very important for campus to built the GHG inventory system and estimate the potential GHG emission reduction. In general, GHG inventory on the campus was taken by the IPCC guidance with the classification of scope 1, 2, and 3. Electricity was the highest portion of GHG emission on the campus as 5,053.90 $tonsCO_2eq/yr$ in 2009. Manufacturing sector was the second high emission and meant GHG in laboratory. Potential GHG reduction was planned by several assumptions such as installation of occupancy sensor, exchanging LED lamp and photovoltaic power generation. These reduction scenarios was simulated by LEAP model. In 2020, outlook of GHG emission was estimated by 17,435.98 tons of $CO_2$ without any plans of reduction. If the reduction scenarios was applied in 2020, GHG emission would be 16,507.60 tons of $CO_2$ as 5.3% potential reduction.

• Journal of Powder Materials
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• v.31 no.2
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• pp.163-168
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• 2024

As the demand for lithium-ion batteries for electric vehicles is increasing, it is important to recover valuable metals from waste lithium-ion batteries. In this study, the effects of gas flow rate and hydrogen partial pressure on hydrogen reduction of NCM-based lithium-ion battery cathode materials were investigated. As the gas flow rate and hydrogen partial pressure increased, the weight loss rate increased significantly from the beginning of the reaction due to the reduction of NiO and CoO by hydrogen. At 700 ℃ and hydrogen partial pressure above 0.5 atm, Ni and Li₂O were produced by hydrogen reduction. From the reduction product and Li recovery rate, the hydrogen reduction of NCM-based cathode materials was significantly affected by hydrogen partial pressure. The Li compounds recovered from the solution after water leaching of the reduction products were LiOH, LiOH·H₂O, and Li₂CO₃, with about 0.02 wt% Al as an impurity.

• Spatial Information Research
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• v.20 no.1
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• pp.19-26
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• 2012

Since $CO_2$ emissions are recognized as the biggest contribution to climate change, the needs and international efforts for $CO_2$ emissions reduction are increasing. The developed countries are driving strategies to boost green industry as a new growth engine. Following this global trend, based on the ongoing U-City project as a new city model, it is required to analyze the changes of $CO_2$ emissions in U-City to identify its potential for reducing carbon dioxide emissions. This study aims at identifying the potential and effects on $CO_2$ reduction by analyzing the level of $CO_2$ emissions before and after introducing U-City. Bundang-Gu, Seongnam-City & Ilsan-Gu, Goyang-City among Phase I new tow ns were selected as model cities before introducing U-City and Dongtan-Dong, Hwaseong-City as a model city after introducing U-City. The result showed 30% reduction of $CO_2$ emissions in the comparison of tw o models.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.17-31
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• 2023

Amidst escalating global warming fueled by indiscriminate fossil fuel consumption, concerted efforts are underway worldwide to mitigate atmospheric carbon dioxide (CO₂) levels. Electrochemical CO₂ reduction technology is recognized as a promising and environmentally friendly approach to convert CO₂ into valuable hydrocarbon compounds, deemed essential for achieving carbon neutrality. Copper, among the various materials used as CO₂ reduction electrodes, is known as the sole metal capable of generating C₂₊ compounds. However, low conversion efficiency and selectivity have hindered its widespread commercialization. This review highlights diverse research endeavors to address these challenges. It explores various studies focused on utilizing copper-based electrodes for CO₂ reduction, offering insights into potential solutions for advancing this crucial technology.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.100-106
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• 2011

This study proposes a $CO_2$ emission reduction method through correlation analysis of a sample building. First, energy saving factors of heating, cooling, lighting were determined for the correlation analysis and $CO_2$ emission contribution rate of the design parameters have been analyzed. Then optimal combination of each design parameter has been drawn. Heat transfer coefficient of walls and windows, air permeability, windows area ratio, and shading devices were selected as applicable energy saving factors of the sample building. Also computer simulation was conducted using experimental design by Orthogonal Arrays of the statistical method. And the contribution rate was estimated by Analysis of Variance-ANOVA. As a result, the $CO_2$ emission in heating was reduced to 51.9%; in cooling to 16.8%; and in lighting to 2% compared to the existing building. The majority of the reduction was presented by heating energy.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.153-161
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• 2008

The guidelines for indoor air quality of public transportations such as subway, train and bus was presented by Korean Ministry of Environment last end of year 2006 based on the great consequence of indoor air quality in daily life. Two main parameters, carbon dioxide($CO_2$) and particulate matters smaller than $10\;{\mu}m(PM_{10})$, were selected as index pollutants for the management of indoor air quality. The former pollutant, $CO_2$, is regarded as index of ventilation status and the major source of $CO_2$ in the train or subway is the exhalation of passengers. It is publically perceived that the high $CO_2$ concentration in a crowded subway will be reduced and ventilated with outdoor air by door-opening taken every 2 or 3 minutes when the train stops each station. However, there has not been any scientific proof and quantitative information on the effect of door-opening on the $CO_2$ reduction by ventilation with outdoor air. In this study, $CO_2$ concentration and number of passengers were measured at each station on the 3 lines of Korail metropolitan subway. In order to evaluate the effect of $CO_2$ reduction by door opening, the theoretical approach using the $CO_2$ balance equation was performed. By comparing the predicted data with monitoring one, the optimum $CO_2$ dilution factor was determined. For the first time, it was quantified that about 35% of $CO_2$ concentration in the subway indoor was removed by the door-opening at each station.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.3
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• pp.319-332
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• 2010

In general, wastewater treatment systems consume high-energy consumption depending on operation characteristics of the facilities. Therefore, greenhouse gas(GHG) reduction activities that are application of digestion gas, induction of renewable energy etc. are conducted to reduce energy consumption and to increase energy independence ratio. In this study, GHG reduction in wastewater treatment system identified, searched application of Clean Development mechanism(CDM) approved methodology. If the methodologies apply to GHG reduction activities such as application of digestion gas, heat pump system using the wastewater as heat source, hydropower using the methodology determined CDM applicability, otherwise through several assumptions calculated expectable GHG reduction emissions and determined CDM applicability. As a result, the order of calculated GHG reduction emission showed that collected and energy generation of digestion gas is 66,775 $tCO_2$/yr, gas engine cogeneration system is 8,182 $tCO_2$/yr, heat pump system using the wastewater as a heat source is 72,715 $tCO_2$/yr, and hydropower is 561 $tCO_2$/yr. Consequently, the order of calculated Certified Emission Reductions(CERs) benefit showed that heat pump system using the wastewater, as a heat source is 1,381 million won/yr was estimated as the highest, followed by a collected and energy generation of digestion gas is 1,268 million won/yr.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.656-657
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• 2006

One append way of liquid state inhibitor was investigated, which putting V, Cr into W-Co composite solutions in the form of ionization. After spray drying and being calcined, W-Co composite oxides could come into being. Then taking fluidization techniques, well-proportioned W-Co composite powder compounded with inhibitor could be produced in the end.