• Environmental Engineering Research
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• 제22권4호
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• pp.407-416
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• 2017

$CO_2$ emission is increasingly focused by public. Beijing and Tianjin are conceived to be a new economic point of growth in China. However, both of them are suffering serious environmental stress. In order to seek for the effect of socioeconomic factors on the $CO_2$ emission of this region, a novel methodology -symbolic regression- is adopted to investigate the relationship between $CO_2$ emission and influential factors of Beijing and Tianjin. Based on this method, $CO_2$ emission models of Beijing and Tianjin are built respectively. The models results manifested that Beijing and Tianjin own different $CO_2$ emission indicators. The RMSE of models in Beijing and Tianjin are 255.39 and 603.99, respectively. Further analysis on indicators and forecast trend shows that $CO_2$ emission of Beijing expresses an inverted-U shaped curve, whilst Tianjin owns a monotonically increasing trend. From analytical results, it could be argued that the diversity rooted in different development orientation and the mixture of different natural and industrial environment. This research further expands the investigation on $CO_2$ emission of Beijing and Tianjin region, and can be used for reference in the study of carbon emissions in similar regions. Based on the investigation, several policy suggestions are presented.

• 한국대기환경학회지
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• 제20권3호
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• pp.281-290
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• 2004

The main purpose of this study was to characterize the air pollutants emission factors in electric power plant (EPP) using fossil fuels. The electric power plant is a major air pollution source, thus knowing the emission characteristics of electric power plant is very important to develop a control strategy. The major air pollutants of concern from EPP slacks are particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO) and heavy metals. Throughout the study, the following results are estimated - PM : 8.671E-05 ∼ 8.724E+01 PM emission (kg) per fuel burned (ton) - SOx : 4.149E-04∼7.877E+01 SOx emission (kg) per fuel burned (ton) - NOx 1.578E-02∼9.857E+00 NOx emission (kg) per fuel burned (ton) - CO : 3.800E-04∼1.291E+00 CO emission (kg) per fuel burned (ton) - Hg : 1.220E+01∼3.108E+02 Hg emission (mg) per fuel burned(ton) From the statistical analysis by Wilcoxon signed ranks test between the emission factors of ours and U.S. EPA's, we can yielded that : p 〉0.05.

• 대한토목학회논문집
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• 제42권3호
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• pp.351-357
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• 2022

본 연구에서는 하수재이용과 해수담수화를 동시에 진행할 수 있는 규모 1,000 m³/d의 FO-RO 융합공정과 동일한 규모의 기존 SWRO 공정의 탄소배출량을 계산하여 비교 분석하였다. FO-RO 융합공정은 FO 공정을 도입하여 RO 공정 원수를 희석시킬 수 있기 때문에 RO 공정의 요구 압력이 감소되고 이는 곧 에너지소비량 감소로 이어진다. 에너지소비량에 따른 탄소배출량은 FO-RO 융합공정이 SWRO 공정보다 -0.73 kgCO₂(coal로 전력생산 시) 낮으며, FO 공정 추가 건설로 인해 발생되는 탄소배출량은 +0.16 kgCO₂로 계산되어 FO-RO 융합공정의 총 탄소 배출량이 더 낮은 것으로 나타났다. 하지만, Coal나 oil과 같은 화석연료로 전력을 생산하지 않고, 전력생산 시 탄소배출량이 적은 nuclear나 solar 등으로 사용하면 FO-RO 융합공정의 총 탄소배출량이 SWRO 공정보다 더 높은 것으로 나타났다. 즉, 탄소배출량 관점에서는 전력생산 시 필요 재료(예: coal, oil, nuclear, solar 등)에 따라 친환경적인 공정 판단 여부가 결정되므로 FO-RO 융합공정 도입 필요성을 좌우하는 핵심 요소라고 할 수 있다.

• Corrosion Science and Technology
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• 제17권2호
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• pp.37-44
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• 2018

Taiwan has a typical marine climate featuring perennial high-temperature and dampness. This climate, together with the emission of various industrial corrosive waste gases in recent years, contributes a lot to the corrosion of metal materials. In this study, samples of carbon steel exposed to various atmospheres in Taiwan were analyzed to investigate the impacts of atmospheric factors on carbon steel corrosion. Carbon steel samples were collected from 87 experimental stations between 2009 and 2012. Statistical analysis was employed to investigate the correlations between the carbon steel corrosion situations and the atmospheric factors such as concentrations of sulfur dioxide or chloride, exposure time, rainfall, etc. The results indicate that for samples from industrial areas, the sulfur dioxide concentration and exposure time during fall and winter are significantly correlated to the condition of the carbon steel corrosion. However, for samples from coastal zones, the significant correlated factors are chloride concentration and wetting time during winter. The results of this study are useful for the development of carbon steel corrosion prediction models.

• 한국대기환경학회지
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• 제31권4호
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• pp.368-377
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• 2015

Bunker C fuel oil is a high-viscosity oil obtained from petroleum distillation as a residue. The sulfur content of bunker C fuel oil is limited to 4.0% or even lower to protect the environment. Because bunker C fuel oil is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, carbon dioxide is emitted as a result of combustion. The objective of this study is to investigate $CO_2$ emission characteristics of bunker C fuel oil by sulfur contents. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and $CO_2$ emission factors were determined. The results showed that hydrogen content increases and carbon content decreases by reducing sulfur contents for bunker C fuel oil with sulfur contents less than 1.0%. For sulfur contents between 1.0% and 4.0%, carbon content increases as sulfur content decreases but there is no evident variation in hydrogen content. Net calorific value increases by reducing sulfur contents. $CO_2$ emission factor, which is calculated by dividing carbon content by net calorific value, decreases as sulfur content decreases for bunker C fuel oil with sulfur contents less than 1.0% but it showed relatively constant values for sulfur contents between 1.0% and 4.0%.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.10-15
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• 2009

Emission regulations on greenhouse gas(GHG) in automobiles have been stringent because of global warming effect. Over 90% of total GHG emission are carbon dioxides and about 20% of this $CO_2$ emission are emitted from automobiles. In this study, 110 vehicles were tested on a chassis dynamometer and $CO_2$ emissions and fuel economy were measured in order to investigate the characteristics of $CO_2$ emission factor from passenger vehicles which are the most dominant vehicle type in Korea. The characteristics of emissions in accordance with displacements, gross vehicle weight, NIER and CVS-75 speed mode were discussed. It was found that vehicles having larger displacement, heavier gross vehicle weight, automatic transmission and specially at cold start emitted more $CO_2$ emissions. From these results, correlation between $CO_2$ emission and fuel economy was also obtained. This study may contribute to evaluate domestic greenhouse gas emissions and establish national policies on climate changes in future.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.24-33
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• 2021

Analysis of long term affecting factors on water quality items of gas emission form (BOD, COD) and leachate emission form (T-N, non-bio-degradable COD (NBDCOD)) was performed for the SUDOKWON 1st Landfill Site (LS1) and 2nd Landfill Site (LS2). As landfill gas was generated, BOD and COD decreased from 6,887 and 20,025 mg/L in 1993 to 49.5 and 670.2 mg/L in 2019, respectively. TN and NBDCOD increased with waste decomposition but gradually decreased after landfill closure because of the precipitation infiltration effect. Due to the drastic decline of carbon in the leachate, the BOD/TN ratios of LS1 and LS2 declined from 13.0 and 17.0 during early stage of the landfill to 0.07 and 0.16 in 2019, respectively; LS2 and NBDCOD/COD increased from 0.25 to 0.65 during the same period. These conditions caused carbon deficiency in denitrification treatment and a chemical post-treatment request for NBDCOD. The different behaviors of gas emission and leachate emission items suggest the necessity of different strategic approaches in the long term perspective.

• 한국대기환경학회지
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• 제20권5호
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• pp.615-623
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• 2004

This study was conducted for developing the emission factors of nitrogen oxide(NOx) and carbon monoxide (CO) from the combustion boilers burning liquefied natural gas (LNG). These emission factors were compared with those of U.S. EPA and European Environment Agency (EEA). NOx and CO concentration in the flow gas were measured using Kane-May, KM9106 and Thermo Environmental Instruments Inc., 42C-HL. Measurement were conducted at thirty industrial and commercial LNG boilers. Emission factors were calculated on the basis of fuel consumption (kg-pollutant/㎥-fuel burned). NOx concentration at industrial boiler was 14~125 ppm and it was measured as 35~125 ppm at commercial boiler. NOx emission factors of industrial boiler and commercial boiler were 1.84kg/$m^3$ and 2.09kg/$m^3$, respectively. NOx emission factor of commercial boiler was higher than that of industrial boiler. The NOx emission factors estimated in this study were lower than those of U.S. EPA and higher than those of EEA. Average CO emission factor of industrial boiler was 0.65 kg/$m^3$ and at commercial boiler it was 0.70kg/$m^3$, CO emission factor at industrial boiler was lower than that at commercial boiler.

• KIEAE Journal
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• 제13권5호
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• pp.79-88
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• 2013

This study creates the evaluation criteria to analyze the $CO_2$ emission quantity in the complex of apartment house among domestic buildings and proposes how to calculate the $CO_2$ emission quantity by the only simple information of apartment house. The study shows that in order to create the index of carbon emission evaluation criteria, $CO_2$ emission quantity for its input materials in these 27 apartment houses are 445,412g-$CO_2/m^2$ for apartment building, 474,322g-$CO_2/m^2$ for the basement parking lot, 483,523g-$CO_2/m^2$ for welfare facility, 729,957g-$CO_2/m^2$ for sales facility, 743,560g-$CO_2/m^2$ for other facility, 26,782g-$CO_2/m^2$ for public facility, 43,659g-$CO_2/m^2$ for landscape, 1,113g-$CO_2/m^2$ for indoor facility, 11,251g-$CO_2/m^2$ for outdoor facility and 891g-$CO_2/m^2$ for common temporary based on the average $CO_2$ emission by facility. We can also see the analysis data that in case of using the selected factors only, the rate of error is 7.51% comparing with the emission quantity by using simplified LCA method this study suggests for the whole range of apartment houses and the rate of error is average 3.24% using selective and main materials. And this it is evaluated that we can get the result which is similar to the actual $CO_2$ emission quantity with only the simple information about the apartment house.

• 한국기후변화학회지
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• 제8권4호
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• pp.415-424
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• 2017

This study was conducted to estimate carbon stocks of Pinus densiflora with drawing volume of trees in each tree height and DBH applying the suitable stem taper equation and tree specific carbon emission factors, using collected growth data from all over the country. Information on distribution area, tree age, tree number per hectare, tree volume and volume stocks were obtained from the $5^{th}$ National Forest Inventory (2006~2010) and Statistical yearbook of forest (2016), and method provided in IPCC GPG was applied to estimate carbon stock and uptake. Performance in predicting stem diameter at a specific point along a stem in Pinus densiflora by applying Kozak's model, $d=a_{1}DBH^{a_2}a_3^{DBH}X^{b_{1}Z^2+b_2ln(Z+0.001)+b_3\sqrt{Z}+b_4e^z+b_5(\frac{DBH}{H})}$, which is well known equation in stem taper estimation, was evaluated with validations statistics, Fitness Index, Bias and Standard Error of Bias. Consequently, Kozak's model turned out to be suitable in all validations statistics. Stem volume table of P. densiflora was derived by applying Kozak's model and carbon stock tables in each tree height and DBH were developed with country-specific carbon emission factors ($WD=0.445t/m^3$, BEF = 1.445, R = 0.255) of P. densiflora. As the results of analysis in carbon uptake for each province, the values were high with Gangwon-do $9.4tCO_2/ha/yr$, Gyeongsandnam-do and Gyeonggi-do $8.7tCO_2/ha/yr$, Chungcheongnam-do $7.9tCO_2/ha/yr$ and Gyeongsangbuk-do $7.8tCO_2/ha/yr$ in order, and Jeju-do was the lowest with $6.8tC/ha/yr$. Total carbon stocks of P. densiflora were 127,677 thousands tC which is 25.5% compared with total percentage of forest and carbon stock per hectare (ha) was $84.5tC/ha/yr$ and $7.8tCO_2/ha/yr$, respectively.