• Journal of Hydrogen and New Energy
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• v.23 no.6
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• pp.581-587
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• 2012

Thermal aging effect on NSR kinetics was studied over Pt/Co/Fe/Ba/$Al_2O_3$ catalyst. The amount of $NO_x$ uptake over Pt/Co/Fe/Ba/$Al_2O_3$ calcined at $400^{\circ}C$ increased with increasing NSR temperature from $200^{\circ}C$ to $400^{\circ}C$, where amount of $NO_x$ uptake is the highest at $400^{\circ}C$ with mol ratio of $NO_x$/Ba = 0.5. Thereafter, the amount of $NO_x$ uptake at $400^{\circ}C$ decreased with the higher calcination temperature, where Pt/Co/Fe/Ba/$Al_2O_3$ catalyst calcined at $700^{\circ}C$ showed an amount of $NO_x$ uptake with the mol ratio of $NO_x$/Ba=0.062. Result of XRD and NSR showed that Fe addition into Pt/Co/Fe/Ba/$Al_2O_3$ suppressed sintering of Pt crystallites and make $NO_x$ uptake larger, compared to no addition of Fe into Pt/Co/Fe/Ba/$Al_2O_3$ catalyst. From BET result, it was found that the change of specific surface area was relatively small by the thermal aging process. Therefore, it was found that the sintering of Pt crystallites caused the decrease of $NO_x$ uptake during NSR reaction and Fe played a role to suppress the sintering process of Pt crystallites caused by thermal aging.

• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.191-197
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• 2003

Sr ferrites with various compositions were applied to the decomposition of $CO_2$ to mitigate the greenhouse effect. In the reduction reaction of Sr ferrites up to 80$0^{\circ}C$, starting temperature was lower with increasing of Sr content in Sr ferrite. However, the reactivity was higher with decreasing Sr content. In the $CO_2$ decomposition reaction with reduced Sr ferrites, the amount of CO and C were depended on the ratio of Sr and Fe in Sr ferrite. With increasing Sr content. larger amount of C were deposited on the surface of ferrite. Therefore, in order to apply Sr ferrites for the decomposition of $CO_2$, it is necessary to control the ratio of Sr and Fe according to the conditions used.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.539-546
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• 2007

Increasing emission of $CO_2$ significantly effects the global warming. Chemical absorption is one of separation methods of $CO_2$ from the industrial flue gases. In this study, the $CO_2$ removal efficiency as well as the $CO_2$ absorption amount of aqueous AMP (2-amino-2-methyl-1-propanol) solutions were measured using the continuous absorption and regeneration apparatus. We investigated the effect of aqueous AMP+AEPD(2-amino-2-ethyl-1, 3-propanediol) and AMP+TIPA (triisopropanolamine) solutions to enhance absorption characteristics of AMP. As a result of this study, the absorption amount and $CO_2$ removal efficiency were increased with adding TIPA into 30 wt.% AMP. The absorption amount and $CO_2$ removal efficiency of aqueous 30 wt.% AMP+5 wt.% TIPA solution were $1.70\;kg-CO_2/kg-absorbent$ and 91.1%, while those of aqueous 30 wt.% AMP solution were $1.58\;kg-CO_2/kg-absorbent$ and 89.3%. In addition, aqueous 30 wt.% AMP+5 wt.% TIPA solution used in the study revealed the high stripping efficiency, which was almost 98%, at the temperature of $110^{\circ}C$. Thus, the temperature of regenerator should be operated at $110^{\circ}C$.

• Journal of Environmental Science International
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• v.25 no.2
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• pp.239-246
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• 2016

This study aims to analyze region-specific trends in changing greenhouse gas emissions in incineration plants of local government where waste heat generated during incineration are reused for the recent five years (2009 to 2013). The greenhouse gas generated from the incineration plants is largely $CO_2$ with a small amount of $CH_4$ and $N_2O$. Most of the incineration plants operated by local government produce steam with waste heat generated from incineration to produce electricity or reuse it for hot water/heating and resident convenience. And steam in some industrial complexes is supplied to companies who require it for obtaining resources for local government or incineration plants. All incineration plants, research targets of this study, are using LNG or diesel fuel as auxiliary fuel for incinerating wastes and some of the facilities are using LFG(Landfill Gas). The calculation of greenhouse gas generated during waste incineration was according to the Local Government's Greenhouse Emissions Calculation Guideline. As a result of calculation, the total amount of greenhouse gas released from all incineration plants for five years was about $3,174,000tCO_2eq$. To look at it by year, the biggest amount was about $877,000tCO_2eq$ in 2013. To look at it by region, Gyeonggido showed the biggest amount (about $163,000tCO_2eq$ annually) and the greenhouse gas emissions per capita was the highest in Ulsan Metropolitan City(about $154kCO_2eq$ annually). As a result of greenhouse gas emissions calculation, some incineration plants showed more emissions by heat recovery than by incineration, which rather reduced the total amount of greenhouse gas emissions. For more accurate calculation of greenhouse gas emissions in the future, input data management system needs to be improved.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1249-1256
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• 1997

Single phase La1-xSrxCoO3 (x≤0.2) was synthesized as a uniform sized 100 nm particulates with relatively high surface area of 20-30 m2/g, at low temperature (≥600 ℃), from a polymeric gel precursors prepared by using poly(vinyl alcohol) as homogenizer. No minor phase developed during the crystallization when polymer/metal mole ratio was higher than 3. As the polymer/metal mole ratio was raised in the gel, the amount of carbonaceous residues in the amorphous solid precursor prepared by heating the gel at 300 ℃ increased. Most of the residues were eliminated by exothermic thermal decomposition around 400 ℃. The amount of residual carbon (less than 1%) left in the crystalline La1-xSrxCoO3 decreased as more polymer was used, eliminating detrimental effect which might be posed by using large amount of organic homogenizer. The crystal structure of La1-xSrxCoO3 synthesized at temperature lower than 800 ℃ was observed to be shifted from rhombohedral to more symmetric cubic. The structure shifted back to rhombohedral as the cubic sample was annealed at 1000 ℃.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.36-42
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• 1998

Ion-selective eleltrodes(ISEs) are simple electrodechemical devices for the direct measurement of ions in the samples. A novel potentiometric biosensor for the determination of L-Malate or D-isocitrate has been developed by using CO2-3 -ISE-FIA system was composed of a pump, an injector, a malic enzyme or isocitric dehydrogenase enzyme reactor, a CO2-3 -ISE, a pH/mV meter, and an integrater. The various factors, such as buffer capacity types of plstericizer and polymer, were optimized for the CO2-3 selectivity. In this novel CO2-3 --ISE-FIA system, the potential difference due to the amount of CO2-3 produced from each enzyme reaction was proportional to the amount of L-malate or D-isocitrate.

• Journal of Environmental Health Sciences
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• v.34 no.3
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• pp.240-246
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• 2008

The purpose of this study was to gain basic information on the characteristics of $CO_2$ adsorption in relation to $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon in a Fixed Bed Reactor. From the results of this study the following conclusions were made: $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon had a longer breakthrough time and more enhanced adsorption capacity than activated carbon alone. When tested with isothermal adsorption and tested for $CO_2$ adsorption the amount of $CO_2$ adsorbed varied with temperature, $CO_2$ inlet concentration, gas flow rate, aspect ratio, etc. Based on the results, when Langmuir, Freundlich and Dubinin-Polanyi adsorption isotherms were used for linear regression of isothermal adsorption data, Langmuir adsorption isotherm was the most suitable. And, the optimum condition for $Na_2CO_3$ and $K_2CO_3$ impregnated activated carbon make-up was 1N and $Li_2CO_3$ was 0.1N. It could be concluded that adsorption capacity was decreased with adsorption temperature and increased gas concentration. When the aspect ratio (L/D) was varied 0.5, 1.0 and 2.0, the significant drop of adsorption amount was observed below 1.0 and breakthrough time was shortened with gas flow rate.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.286-293
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• 1998

Two methods were used to enhance the adsorption capacity of activated carbons. One is to impregnate activated carbons with chemical compounds which have a good affinity for $CO_2$. The other is to activate by heat-treating after impregnation with KOH on activated carbons(AC). The chemical compounds impregnated on AC were alkali metal, alkaline earth metal, and transition metal chlorides. The adsorption capacity of $CO_2$ on AC impregnated with these metals was less than that of pure AC. These compounds have not the chemical affinity for $CO_2$ and obstruct the micropore of AC. The experiment of breakthrough for $CO_2$ on AC impregnated with KOH showed the increase of the adsorbed amount of $CO_2$ in influent gases containing water vapor. This means that KOH adsorbes $CO_2$ gas. However, the adsorbents impregnated with KOH had not the reproducibility because of the production of $K_2CO_3$ by the reaction of KOH with $CO_2$. The amount of $CO_2$ adsorbed on the heat-treated AC at $800^{\circ}C$ increased with the amount of impregnation. The adsorption capacity of $CO_2$ was the largest when the ratio of weight of KOH to AC equal to 4. The isosteric heat of adsorption was calculated by the equation of Clausius-Clapeyron form adsorption capacity data of $CO_2$ for the temperature change. In addition, the characteristics of $CO_2$ breakthrough curve were surveyed for the change of flow rate and concentration.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.619-627
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• 2012

In order to determine reduction of greenhouse gas emissions (GHGs) when the submerged membrane bioreactor with granular sulfur (MBR-GS) is used in wastewater treatment plant (WTP), the amount of GHGs was compared and analyzed in the advanced treatment process of P wastewater treatment plant (WTP). The amount of GHGs was estimated by classifying as construction and operation phase in WTP. The amount of GHGs in construction phase was evaluated from multiplying raw materials by using carbon emission factors. Also the amount of GHGs in operating phase was calculated by using total electricity consumption and carbon emission factor. The construction of anoxic tank and secondary settling tank is unnecessary, because the MBR-GS conducts simultaneously the nitrification and denitrification in aeration tank and filtration by hollow fiber membrane. The amount of $CO_2$, $CH_4$, and $N_2O$ emitted by constructing the MBR-GS was 6.44E+06 kg, 8.16E+03 kg and 1.38E+01 kg, respectively. The result shows that the GHGs was reduced about 47 % as compared with the construction in the MLE process. In operating the MBR-GS, the electricity is not required in the biological reactor and secondary setting tank. Thus, the amount of $CO_2$, $CH_4$, and $N_2O$ emitted by operating in the MBR-GS was 7.39E+05 kg/yr, 5.80E+02 kg/yr and 2.44E+00 kg/yr, respectively. The result shows that the GHGs were reduced about 37 % as compared with the operation in the MLE process. Also, $LCCO_2$(Life Cycle $CO_2$) was compared and analyzed between MLE process and MBR-GS. The amount of $LCCO_2 $emitted from the MLE process and MBR-GS was 3.56E+04 ton $CO_2$ and 2.12E+04 ton $CO_2$, respectively. The result shows that the GHGs in MBR-GS were reduced to about 40 % as compared in the MLE process during life cycle. As a result, sulfur-utilizing autotrophic denitrification process (SADP) is expected to be utilized as the cost-effective advanced treatment process, owing to not only high nitrogen removal efficiency but also the GHGs reduction in construction and operation stage.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.643-650
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• 2003

We analyzed the amount of environmental loads, and the amount of energy consumption through life cycle assessment from a discharge stage to the ultimate disposal to municipal solid waste in Seoul. We carried out inventory analysis of the amount of environmental loads that made the object range collection, intermediate treatment, and the final treatment, and took into consideration each stage exceptions CO$_2$ and NOx , the amount of SOx discharge, and energy consumption. We applied the data of an object model, and acquisition processed the scale of an object model suitably and applied to it to difficult data using the data of the Yokohama City incineration plant in Japan. The amount of environmental loads per Iton of municipal waste were analyzed CO$_2$ 0.4C-ton, SOx 0.4kg and NOx 0.8kg. Moreover, the amount of energy consumption which is 2.4Gcal was computed.