• Asian Journal of Atmospheric Environment
• /
• 제4권3호
• /
• pp.166-176
• /
• 2010

In this research, the environmental behavior of carbon dioxide ($CO_2$) was investigated in a mountainous site in the proximity of a highly industrialized megacity, Seoul, Korea. The concentration data of $CO_2$ monitored routinely at hourly intervals at Mt. Gwan-Ak (GA), Seoul, Korea throughout 2009 were analyzed in several respects. The mean $CO_2$ value was $405{\pm}12.1$ ppm (median=403 ppm) with a range of 344 to 508 ppm (N=8548). The analysis of its seasonal trend indicated that the $CO_2$ levels peaked in the winter but reached a minimum in fall. If the short-term trend is analyzed, the $CO_2$ values generally peaked during daytime along with the presence of two shoulders; this is suspected to be indicative of strong man-made effects (e.g., traffic activities). It is seen that the general patterns of $CO_2$ distribution in this study area are highly comparable to those typically found in urban areas with strong signals of anthropogenic activities.

• 한국대기환경학회지
• /
• 제17권4호
• /
• pp.321-329
• /
• 2001

This study included three experiments to evaluate in-vehicle exposures to PM10 and CO: 1) evaluation of in-passenger car exposures, 2) evaluation of in-public bus exposures, and 3) simultaneous evaluation of in-passenger car and in -university bus exposures. The tests of four factors (transportation mode, passenger-car type, commute period, and commute season were focused. A total of 40 actual passenger car commuters, 20 public bus commuters, and four university buses were recruited or surveyed. The same commuters ware participated in both the summer and winter studied. Two factory such as transportation mode and passenger-car type were found to have little effect on the in-vehicle levels of PM10 and CO. Commute period was found to have little effect on the in-vehicle CO levels. Conversely, the other factor, commuting season was found to influence on the in-vehicle levels of PM10 and CO. The present study also confirmed that under the Korean commute conditions, vehicle interiors are an important microenvironment for exposure to PM10 and CO. This was supported by finding that the in-vehicle Air levels were much higher than ambient air levels reported by several previous studies. The mean in -vehicle PM10 concentrations were 114 and 103$\mu\textrm{g}$/m$^3$for passenger cars and public buses, respectively. For CO, the mean in-vehicle concentrations were 2.9 and 2.6 ppm for passenger cars and public louses, respectively.

• 대한화학회지
• /
• 제64권6호
• /
• pp.334-344
• /
• 2020

본 연구는 그래핀과 유사한 IV족 나노 시트로서 말단을 수소로 처리한 게르마닌(Germanene) 이차원(2D) 시트에 여러 유해 가스(COx, NOx, SOx)를 흡착시켰을 때 구조적 변화와 흡착에너지를 이론적으로 계산하였다. 이론 방법은 밀도 범함수 이론(density functional theory, DFT) 가운데 B3LYP와 CAM-B3lYP을 사용하였으며, 바탕집합(basis set)으로는 cc-pvDZ를 사용하였다. 분자 구조를 각 이론 수준에서 최적화한 후 진동 주파수를 계산하여 열역학적으로 가장 안정한 분자 구조를 확인하였다. 게르마닌 시트에 기체의 흡착은 CO, CO2, NO, SO2 가스의 경우 물리 흡착을 나타내었으며, NO2, SO, SO2 등은 화학 흡착을 나타내었다.

• 한국대기환경학회지
• /
• 제28권2호
• /
• pp.190-202
• /
• 2012

Emissions of air pollutants and greenhouse gases (GHGs) by aircraft at the Gimhae International Airport (GIA) were investigated using the Emissions and Dispersion Modeling System (EDMS) version 5.1.3. The number of Landing and Take-Off (LTO) at the GIA for aircraft B737 was dominant, accounting for more than 60% of the total LTOs. For air pollutant emissions, CO was the most dominant pollutant by aircraft, followed by $NO_x$, VOCs, $SO_x$, etc. The emissions of CO, $NO_x$, and VOCs in 2009 (and 2010) at the GIA were 974 (968), 447 (433), 118 (122) ton/yr, respectively. The emissions of GHGs such as $CO_2$, $CH_4$, and $N_2O$ in 2009 (and 2010) were 110,795 (111,114), -0.157 (-0.151), and 1,989 (1,998) ton/yr, respectively. The negative number in $CH_4$ emission represents the consumption of atmospheric $CH_4$ in the engine. In addition, the emissions of most air pollutants (except for $PM_{10}$) and GHGs were estimated to be high in Taxi-Out and Climb-Out modes.

• Asian Journal of Atmospheric Environment
• /
• 제7권1호
• /
• pp.48-55
• /
• 2013

The purpose of this study was to develop a $CO_2$ emission factor for refuse plastic fuel (RPF) combustion facilities, and calculate the $CO_2$ emissions from these facilities. The $CO_2$ reduction from using these facilities was analyzed by comparing $CO_2$ emission to facilities using fossil fuels. The average $CO_2$ emission factor from RPF combustion facilities was 59.7 Mg $CO_2$/TJ. In addition, fossil fuel and RPF use were compared using net calorific value (NCV). Domestic RPF consumption in 2011 was 240,000 Mg/yr, which was compared to fossil fuels using NCV. B-C oil use, which has the same NCV, was equal to RPF use. In contrast, bituminous and anthracite were estimated at 369,231 Mg/yr and 355,556 Mg/yr, respectively. In addition, the reduction in $CO_2$ emissions due to the alternative fuel was analyzed. $CO_2$ emissions were reduced by more than 350 Mg $CO_2$/yr compared to bituminous and anthracite. We confirmed that using RPF, an alternative fuel, can reduce $CO_2$ emissions.

• 공업화학
• /
• 제22권6호
• /
• pp.653-657
• /
• 2011

대기압 플라즈마 반응기를 이용한 메탄과 이산화탄소의 전환처리로 수소와 일산화탄소로 구성된 합성가스를 제조하는 공정특성을 연구하였다. 유전체 격벽 방전방식의 플라즈마 반응기를 인가전력, 혼합가스의 구성비 및 사용된 반응기의 갯수 등의 공정변수들에 대하여 메탄과 이산화탄소의 전환율에 미치는 영향이 분석되었다. 인가전력의 공급에 따라 플라즈마 반응기 자체의 온도 상승이 일어나지만 반응기 온도 증가가 반응기체의 전환율 향상에 효과가 크지 않았다. 그러나 인가전력이 증가할수록 메탄과 이산화탄소의 전환율이 크게 증가하였다. 반응기체인 $CH_4/CO_2$ 비가 커질수록 $CH_4$의 전환율은 감소하나 $CO_2$의 경우는 증가하였다. 전체적으로 반응에 따른 $CH_4$의 전환율이 $CO_2$의 전환율보다 큰 경향성을 보인다.

• 생물환경조절학회지
• /
• 제18권2호
• /
• pp.148-152
• /
• 2009

본 연구는 배추 재배시 기후변화에 대비하여 고온과 고농도의 이산화탄소 조건에서 생육반응과 세포조직의 변화를 알아보고자 수행하였다. 처리는 '대기중 온도+대기중 $CO_{2}$ 농도(Control)', '대기중 온도+대기보다 $CO_{2}$ 2배 상승(Elevated $CO_{2}$)' '(대기온도보다 4$^{\circ}C$ 상승+대기중 $CO_{2}$ 농도(Elevated temp.)', '대기온도보다 4$^{\circ}C$ 상승+대기보다 $CO_{2}$ 2배 상승(Elevated temp.+$CO_{2}$)'의 4가지 조건으로 처리하였다. 그 결과, 대기조건보다 온도만 높아지게 되면 배추의 생체중이 현저하게 저하되어 수량이 떨어지는 것으로 나타났고, 온도가 높아지고 $CO_{2}$ 농도가 동시에 올라가게 되면 생육이 어느정도 회복되는 것으로 나타났다. 또한 칼륨과 인산함량은 처리별로 차이가 없었지만 칼슘과 총질소함량은 온도만 높인 처리에서 높았고, 마그네슘 함량은 온도와 $CO_{2}$ 농도를 동시에 높인 처리에서 높게 나타났다. 배추잎의 세포 관찰결과 $CO_{2}$ 농도를 2배 정도 높인 처리에서 잎내의 전분함량이 증가하는 것으로 나타났고, 온도만 높인 처리에서 전분 함량이 가장 낮았다.

• 한국환경과학회지
• /
• 제12권9호
• /
• pp.987-996
• /
• 2003

In this study, we analyzed the relationship between the time-variation trend of air pollution concentration index and the meteorological conditions with CO(carbon monoxide) concentration and meteorological observation data in high-CO episode days. CO is a representative automobile air pollutant. The results are as follows; 1. Most of the high-CO episode days within 30 classes appeared in winter season. 2. Most of them appeared under the surface weather conditions with east-west high-pressure system. The surface winds in this high-pressure area were very light. 3. The high-CO episode days were due to unusual accumulation within urban atmosphere in the morning. 4. The Atmospheric stabilities were more stable, and then the wind-ventilation conditions were worse than yearly mean atmospheric condition in Daegu.

• 한국대기환경학회지
• /
• 제33권5호
• /
• pp.473-479
• /
• 2017

This study was designed to understand characteristics of oxy-combustion of coal, dried sewage sludge and solid refuse fuel (SRF). Thermogravimetric analysis was conducted by burning the fuels with air, 21% oxygen ($O_2$)/79% carbon dioxide ($CO_2$) and 30% $O_2/70%$ $CO_2$. Heating rates were varied as 5, 10, 25, 40 and $100^{\circ}C/min$. Complete coal combustion was found at the heating rates of 5, 10, 25 and $40^{\circ}C/min$, and different combustion behavior was found with the gas composition at the heating rates of 10, 25, 40 and $100^{\circ}C/min$. Coal combustion with 30% $O_2/70%$ $CO_2$ showed the highest while coal combustion with 21% $O_2/79%$ $CO_2$ showed the lowest combustion rate. On the other hand, the combustion of dried sewage sludge and SRF showed similar combustion behavior with respect to the combustion gas composition. This suggests that oxy-combustion of dried sewage sludge and SRF which contain a large amount of volatile matter may show similar combustion behavior to their air combustion.

• 한국대기환경학회지
• /
• 제32권2호
• /
• pp.176-183
• /
• 2016

Activated carbon fibers (ACFs) for $CO_2$ adsorption were prepared from polyacrylonitrile (PAN) fiber through the systematic processes such as oxidation, activation and amination with the focus on the formation of nitration functional groups. Textural analysis of test samples revealed the decrease of specific surface area and pore volume by chemical activation including amination. The ratio of micropores to the total volume was 0.85 to 0.91, which was high enough with the pore size of 1.57 to 1.77 nm. Nitrogen compounds such as imine, pyridine and pyrrole presenting favorable interforces to $CO_2$ molecules were formed throughout the whole preparation steps. The aminated ACF adsorbent showed the enhanced adsorption capacity, 0.40 mmol/g for low-level $CO_2$ flow (3000 ppm) at room temperature. Selectivity of $CO_2$ against dry air ($O_2$ & $N_2$) also increased from 1.00 to 4.66 by amination.