• Journal of Climate Change Research
• /
• v.4 no.3
• /
• pp.235-244
• /
• 2013

Carbon dioxide emission estimation methods consist of four tiers according to the IPCC guideline. In this study, estimated results by tier 3 and tier 4 were compared with the theoretically calculated $CO_2$ emissions based on the mass balance approach for a gas fired power plant between March and May 2011. It was found that the relative differences were upto 17% between the measured emissions by tier 4 and theoretically estimated emissions, while the results of tier 3 were similar to those from theoretically estimated ones. The comparisons suggested the possibility of misestimation due to replacing missing, abnormal, or invalid data in continuous emissions monitoring system. When using only the data without those missing, abnormal, or invalid data, the relative differences decreased somewhat but still showed consistent differences depending on the stack. It is suggested that this differences might be due to the accuracy of the measurement instruments for the tier 4, especially, for the flow rate measurement instrument.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.502-509
• /
• 2013

To estimate greenhouse gas (GHG) emission, we established inventory of conventional rice cultivation from farmers in Gunsan and Iksan, Jeonbuk province in 2011~2012. This study was to calculate carbon footprint and to analyse the major factor of GHGs. We carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we tried to suggest agricultural methods to reduce GHGs that farmers of this case study can apply. Carbon footprint of rice production unit of 1 kg was 2.21 kg $CO_2.-eq.kg^{-1}$. Although amount of $CO_2$ emissions is largest among GHGs, methane had the highest contribution of carbon footprint on rice production system after methane was converted to carbon dioxide equivalent ($CO_2$-eq.) multiplied by the global warming potential (GWP). Source of $CO_2$ in the cultivation of rice farming is incomplete combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ emitted during rice cultivation and major factor of $CH_4$ emission is flooded paddy field in anaerobic condition. Most of the $N_2O$ emitted from rice cultivation process and major sources of $N_2O$ emission is application of fertilizer such as compound fertilizer, urea, orgainc fertilizer, etc. As a result of sensitivity analysis due to the variation in energy consumption, diesel had the highest sensitivity among the energies inputs. If diesel consumption is reduced by 10%, it could be estimated that $CO_2$ potential reduction is about 2.5%. When application rate of compound fertilizer reduces by 10%, the potential reduction is calculated to be approximately 1% for $CO_2$ and approximately 1.8% for $N_2O$. When drainage duration is decreased until 10 days, methane emissions is reduced by approximately 4.5%. That is to say drainage days, tillage, and reducing diesel consumption were the main sources having the largest effect of GHG reduction due to changing amount of inputs. Accordingly, proposed methods to decrease GHG emissions were no-tillage, midsummer drainage, etc.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.1370-1376
• /
• 2012

This study tried to analyze $CO_2$ emission volume as green-house gases by application of land use patterns and transport policies in District Unit Design. It is postulated a Toy network and various scenarios which are combined land use patterns and transport policies for analyzing $CO_2$ gas reduction. As results, this study shows best District Unit Design technique is the policy that develop mid block and introduction of car free zone to inner 2 way streets. Worst design technique is the policy that make hierarchical network and introduction of access control to outer roads that have been known as a best road policy till nowadays. Therefore, we need more carefully introduce design technique for reduction of $CO_2$ in District Unit.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.05a
• /
• pp.250-251
• /
• 2014

With the recent movement toward sustainable development, many efforts have been made to reduce environmental loads in various domains of industry. In particular, a great deal of research and technology development has been underway on approaches to reducing industrial waste and the emission of greenhouse gases. For this reason, a quantitative analysis of the reduction in CO₂ emission that could be achieved by replacing limestone material with cementitious waste powder was performed in this study. Through the analysis, it was found that CO₂ emissions were reduced by up to 50 percent compared with the scenario in which OPC was used, which suggests that it is possible to reduce global CO₂ emissions by approximately 5percent, or by 446.4 Tg of the 965 Tg of CO₂ emissions generated by the cement industry, in the total global CO₂ emissions of 19300Tg.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.416-416
• /
• 2019

육상 담수는 대기중 이산화탄소($CO_2$) 배출의 중요한 발생원으로 주목되고 있다. 하천 및 강에서 대기중으로 배출되는 $CO_2$는 전 세계 탄소순환의 핵심요소이며, 대부분의 하천과 강은 $CO_2$로 과포화 되어있다. 세계적으로 하천 및 강의 $CO_2$ 배출량은 호수 및 저수지의 배출량보다 약 5배 많은 것으로 보고되고 있으나, 국내연구에서는 연구사례가 드물다. 따라서 본 연구의 목적은 낙동강 중하류에 위치해있는 강정고령보(GGW), 달성보(DSW), 합천창녕보(HCW), 창녕함안보(CHW)에서 발생되는 순 대기 배출 플럭스(Net Atmospheric Flux, NAF)의 동적 변동 특성을 분석하고, 데이터마이닝 기법을 적용하여 쉽게 수집할 수 있는 물리적 및 수질 변수로 $CO_2$ NAF를 추정하는데 사용할 수 있는 간략한 예측 모델을 개발하는데 있다. $CO_2$ NAF는 대기-수면 경계면에서의 $CO_2$ 부분압($pCO_2$)의 차에 기체전달속도를 곱하여 산정하였으며, 기체전달속도는 Cole and Caraco(1998)가 제안한 식을 사용하였다. 담수와 해수의 탄산염 시스템에서 열역학적 화학평형을 모두 고려한 $CO_2$SYS 프로그램을 사용하여 수중의 $pCO_2$를 산정하였고, $CO_2$ NAF는 Henry의 법칙과 Fick의 1차 확산법칙을 사용하여 계산하였다. $CO_2$ NAF의 시간적 변동성에 영향을 미치는 환경요인을 평가하기 위해서 상관분석, 주성분분석(Principal Component Analysis; PCA), 단계적다중회귀모델(Step-wise Multiple Linear Regression; SMLR), 랜덤포레스트(Random Forest; RF)방법을 사용하였다. SMLR 모델은 R package인 olsrr, RF 모델은 R package인 caret, randomForest를 이용하여 분석하였다. 연구 결과, 4개 보 상류 하천구간은 조류의 성장이 활발한 일부 기간을 제외한 대부분의 기간에서 $CO_2$를 대기로 배출하는 종속영양시스템(Heterotrophic system)을 보였다. $CO_2$ NAF의 중위값은 HCW에서 최소 $391.5mg-CO_2/m^2day$, DSW에서 최대 $1472.7mg-CO_2/m^2day$였다. 모든 보에서 NAF는 pH와 강한 음의 상관관계를 보였으며, $pCO_2$와 Chl-a도 음의 상관관계를 보였다. 이는 조류가 수중에서 $CO_2$를 소비하고 pH를 증가시키기 때문이다. PCA 분석 결과, NAF와 $pCO_2$가 높은 공분산을 보였으며, pH와 Chl-a는 반대 방향으로 군집되어 상관분석과 동일한 결과를 보였다. 이 연구를 통해 개발된 SMLR 모델과 RF 모델의 Adj. $R^2$ 값은 모든 보에서 0.77 이상으로 나왔으며, $pCO_2$ 측정 데이터가 없더라도 하천의 $CO_2$ NAF를 추정하는 방법으로 사용될 수 있을 것으로 평가된다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.1191-1202
• /
• 2013

The former researches on earthwork automation were mainly focused on GPS and sensor application, environment modelling, equipment path planning, work information management, and remote control etc. Recently, reducing $CO_2$ emission becomes one of main focuses for an automation research. In the case of earthwork operations, many kinds of construction machines or robots are involved, which can cause high level of $CO_2$ in a construction site. An effective earthwork plan and construction machine operation can both increase productivity and safety and decrease $CO_2$ emission level. In this research, some automation concepts for green earthworks are suggested such as a 3D construction site model, a 3D earthwork distribution based on two different earthwork methods, and an earthwork package construction method. A excel-based simulator is developed to generate the 3D earthwork distribution and to estimate the level of $CO_2$ emission for the given earthwork.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.159-169
• /
• 2016

In this study, the effects of MTBE contents as oxygenates in gasoline on exhaust emissions and fuel economy in MPI and GDi vehicles have been investigated. Various oxygen contents have been selected such as 0, 1.0, 2.3 and 2.7 wt%. FTP-75 and HWFET modes as fuel economy test methods which are widely used in Republic of Korea and US were applied to investigate exhaust emissions from the test vehicles. Emissions of CO, NMHC and NOx did not show significant correlation with oxygen contents in gasoline fuels, although having slight difference with these contents. In addition, CO2 emissions were not significantly changed with respect to oxygen content. But in case of warm-up and FTP-75 and HWFET modes including high speed regimes, CO2 emissions showed inverse correlation with oxygen contents. Particulate number concentration was inversely proportional to the oxygen contents, having the minimum value at the condition of 2.3 wt%. In case of fuel economy through carbon balance method, the highest value has been obtained at 2.3 wt% and there was positive correlation with oxygen contents and fuel economy.

• Journal of the Korea Concrete Institute
• /
• v.29 no.4
• /
• pp.379-387
• /
• 2017

The objective of this study is to develop sustainable PVA fiber-reinforced cementitious composites (FRCCs) that could exhibit comparable strength level to normal PVA FRCCs with no recycled materials. To evaluate mechanical properties of the FRCCs, compressive, flexural and direct tensile tests were conducted. In addition to the test, to calculate amount of carbon dioxide ($CO_2$) emission at the stage of manufacturing the FRCCs, life cycle inventory data base (LCI DB) were referenced from domestic and Japan. From the test results, the mechanical properties such as compressive, flexural and direct tensile strengths were decreased as the replacement ratio of recycled materials increased. And it was determined that the amount of $CO_2$ emission was reduced for the specimens with higher water-binder ratio (W/B) and replacement ratios. It was also found that binder intensity ($B_i$) value was higher as replacement ratio of fly ash (FA) increased. This result means that larger amount of FA is need to deliver one unit of a given performance indicator (1 MPa of strength) of FRCCs compared to that of ordinary portland cement (OPC). As a result, it could be concluded that FRCCs with W/B 45% replaced by FA 25% and recycled sand (RS) 25% is desirable for both target performance and $CO_2$ emission.

• Journal of Korea Port Economic Association
• /
• v.37 no.1
• /
• pp.143-157
• /
• 2021

International organizations such as the World Health Organization, the Organization for Economic Development and Cooperation, and major developed countries recognize the seriousness of air pollution. International organizations such as the International Maritime Organization have also implemented various regulations to reduce air pollution from ships. In line with this international trend, the government has also enacted a special law on improving air quality in port areas, and is making efforts to reduce air pollution caused by ports. The purpose of the Special Act is to implement comprehensive policies to improve air quality in port areas. This study sought to identify the emissions of each source of air pollutants originating from the port and prepare basic data on setting the policy priorities. To this end, the analysis was conducted in six categories: ships, vehicles, loading and unloading equipment, railways, unloading/wild ash dust, road ash dust, and the methodology presented by the European Environment Agency(EEA) and the United States Environmental Protection Agency(EPA). The pollutants subject to analysis were analyzed for carbon monoxide(CO), nitrogen oxides (NOX), sulfur oxides(SOX), total airborne materials(TSP), particulate matter(PM10, PM2.5), and ammonia(NH3). The analysis showed a total of 7,122 tons of emissions. By substance, NOX accounted for the largest portion of 5,084 tons, followed by CO (984 tons), SOX (530 tons), and TSP (335 tons). By source of emissions, ships accounted for the largest portion with 4,107 tons, followed by vehicles with 2,622 tons, showing high emissions. This proved to be the main cause of port air pollution, with 57.6% and 36.8% of total emissions, respectively, suggesting the need for countermeasures against these sources.

• Environmental and Resource Economics Review
• /
• v.22 no.3
• /
• pp.459-479
• /
• 2013

To assess the feasibility of 'low carbon, sustainable growth' policy pursued of the Chinese government, this paper first measures technical efficiency, $CO_2$ shadow prices, and indirect Morishima elasticity of substitution between capital and energy for 24 of manufacturing sectors in Beijing and Chongqing, in which China launched pilot carbon emissions trading scheme, by estimating the input distance function. Based on these results, then the potential for $CO_2$ reduction, cost savings from emissions trading, and the effectiveness of capital investment in reducing $CO_2$ are compared across industries and provinces. In 2010, manufacturing industries in Beijing and Chongqing could potentially reduce the largest $CO_2$ emissions, amounting 5.2 and 17 million tons, respectively, by achieving 100% technical efficiency. While, on average, Chongqing has a comparative advantage in the cost savings from carbon trading over Beijing, Beijing is more likely to reduce $CO_2$ by expanding capital investment.