• 에너지공학
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• 제23권2호
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• pp.170-174
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• 2014

This paper presents the influences of ethanol addition to gasoline on bench test a spark ignition engine performances and emissions characteristics. The use of ethanol gasoline blended fuels decrease the brake power and brake torque, and increases the brake specific fuel consumption (BSFC). Ethanol gasoline blended fuels show lower brake torque and brake power and higher BSFC than gasoline. When ethanol containing oxygen is blended with gasoline, the combustion of the engine becomes better and therefore CO emission is reduced. HC emissions decrease to some extent as ethanol added to gasoline increase, as the percentage of ethanol in the blends increased, NOx emission was decreased under various engine speeds.

• 유기물자원화
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• 제28권1호
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• pp.37-51
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• 2020

2015년 말 채택된 파리협정으로 2023년부터 5년 단위로 국제이행점검(Global stock-taking)이 진행될 예정이며, 국가 온실가스 인벤토리와 온실가스 감축 목표 달성 경과 등을 의무적으로 보고해야 한다. 이에 대비하여 온실가스 배출량 산정의 신뢰도를 향상시키고, 온실가스 배출원별 특성 파악과 배출량 관리가 중요한 시점이다. 이에 본 연구에서는 폐기물 매립 부문을 대상으로 2000 GPG, 2006 IPCC 가이드라인 및 2019 Refinement 산정방법에 따라 온실가스 배출량을 비교·분석하였다. 그 결과, 2016년 기준 시나리오 1에서는 2,287 Gg CO₂_eq, 시나리오 2-1은 1,870 Gg CO₂_eq, 시나리오 2-2는 10,886 Gg CO₂_eq, 시나리오 2-3은 10,629 Gg CO₂_eq, 시나리오 3은 12,468 Gg CO₂_eq으로 나타나 2000 GPG 대비 2006 IPCC 가이드라인 적용 시 온실가스 배출량이 증가하는 것으로 나타났다. 이러한 배출량 변화의 차이는 산정방식의 변화와 적용되는 배출계수 값에 기인하였으며, 이에 우리나라 특성에 따른 배출계수의 국가고유값 개발이 시급한 것으로 나타났다.

• 한국대기환경학회지
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• 제20권4호
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• pp.539-553
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• 2004

Up to the present time, many methods to estimate emissions from a particular diesel engines have wholly depended on the quantity of diesel fuel consumed. Then, the recommended emission factors were normalized by fuel consumption, and further total activity was estimated by the total fuel consumed. One of main purposes in the study is newly to develop emission factors for the railroad diesel rolling stock (RDRS) and to estimate a total amount of major gaseous pollutants from the RDRS in Korea. Prior to develop a Korean mode emission factor. the emission factor from the USEPA was simply applied for comparative studies. When applying the USEPA emission factors, total exhaust emissions from the RDRS in Korea were estimated by 28,117tons of NOx, 2,832.3tons of CO, and 1,237.5tons of HC, etc in 2001. In this study, a emission factor for the RDRS, so called the KoRail mode (the Korean Railroad mode) has been developed on the basis of analyzing the driving pattern of the Gyeongbu-Line especially for the line-haul mode. Explicitly to make the site specific emission factors, many uncertainty problems concerning weighting factors for each power mode, limited emission test, incomplete data for RDRS, and other important input parameters were extensively examined. Total exhaust emissions by KoRail mode in Korea were estimated by 10,960tons of NOx, and 4,622tons of CO, and so on in the year of 2001. The emissions estimated by the USEPA mode were 2.6 times higher for NOx, and 1.6 times lower for CO than those by the KoRail mode. As a conclusion, based on the emission calculated from both the USEPA mode and the KoRail mode, the RDRS is considered as one of the significant mobile sources for major gaseous pollutants and thus management plans an(1 control strategies for the RDRS must be established to improve air quality near future in Korea.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2303-2309
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• 2004

Flue gas recirculation (FGR) is a method widely adopted to control NOx in combustion system. The recirculated flue gas decreases flame temperature and reaction rate, resulting in the decrease in thermal NO production. Recently, it has been demonstrated that the recirculated flue gas in fuel stream, that is, the fuel induced recirculation (FIR), could enhance a much improved reduction in NOx per unit mass of recirculated gas, as compared to the conventional FGR in air. In the present study, the effect of FGR/FIR methods on NOx reduction in turbulent swirl flames by using N$_2$ and CO$_2$ as diluent gases to simulate flue gases. Results show that CO$_2$ dilution is more effective in NO reduction because of large temperature drop due to the larger specific heat of CO$_2$ compared to N$_2$ and FIR is more effective to reduce NO emission than FGR when the same recirculation ratio of dilution gas is used.

• Carbon letters
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• 제25권
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• pp.14-24
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• 2018

Electrochemical properties and performance of composites performed by incorporating metal oxide or metal hydroxide on carbon materials based on graphene and carbon nanotube (CNT) were analyzed. From the surface analysis by field emission scanning electron microscopy and field emission transmission electron microscopy, it was confirmed that graphene, CNT and metal materials are well dispersed in the ternary composites. In addition, structural and elemental analyses of the composite were conducted. The electrochemical characteristics of the ternary composites were analyzed by cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy in 6 M KOH, or $1M\;Na_2SO_4$ electrolyte solution. The highest specific capacitance was $1622F\;g^{-1}$ obtained for NiCo-containing graphene with NiCo ratio of 2 to 1 (GNiCo 2:1) and the GNS/single-walled carbon $nanotubes/Ni(OH)_2$ (20 wt%) composite had the maximum specific capacitance of $1149F\;g^{-1}$. The specific capacitance and rate-capability of the $CNT/MnO_2/reduced$ graphene oxide (RGO) composites were improved as compared to the $MnO_2/RGO$ composites without CNTs. The $MnO_2/RGO$ composite containing 20 wt% CNT with reference to RGO exhibited the best specific capacitance of $208.9F\;g^{-1}$ at a current density of $0.5A\;g^{-1}$ and 77.2% capacitance retention at a current density of $10A\;g^{-1}$.

• Advances in Computational Design
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• 제4권4호
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• pp.367-379
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• 2019

Multiple Inputs and Multiple Outputs (MIMO) Fuzzy logic model is developed to predict the engine performance and emission characteristics of pongamia pinnata biodiesel with hydrogen injection. Engine performance and emission characteristics such as brake thermal efficiency (BTE), brake specific energy consumption (BSEC), hydrocarbon (HC), carbon monoxide (CO), carbon dioxide ($CO_2$) and nitrous oxides ($NO_X$) were considered. Experimental investigations were carried out by using four stroke single cylinder constant speed compression ignition engine with the rated power of 5.2 kW at variable load conditions. The performance and emission characteristics are measured using an Exhaust gas analyzer, smoke meter, piezoelectric pressure transducer and crank angle encoder for different fuel blends (Diesel, B10, B20 and B30) and engine load conditions. Fuzzy logic model uses triangular and trapezoidal membership function because of its higher predictive accuracy to predict the engine performance and emission characteristics. Computational results clearly demonstrate that, the proposed fuzzy model has produced fewer deviations and has exhibited higher predictive accuracy with acceptable determination correlation coefficients of 0.99136 to 1 with experimental values. The developed fuzzy logic model has produced good correlation between the fuzzy predicted and experimental values. So it is found to be useful for predicting the engine performance and emission characteristics with limited number of available data.

• 대한안전경영과학회지
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• 제10권4호
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• pp.229-240
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• 2008

With the effectuation of Kyoto Protocol, one of the important movement throughout the world is reducing the emission of greenhouse gas which is the main reason of making global warming. The actual factor of greenhouse gas is CO2, and in year of 2002 20% of total CO2 emission was produced only through transportation throughout the South Korea. In the contrary, the recycling of municipal wastes in South Korea was 44.0% in 2002, but it will be targeted upto 53.5% in 2011. All of these show environment-conscious logistics should be implemented together throughout the each stage of distribution with the development of product and service. This study applied survey research for the activities affecting to the emission of CO2 and packaging wastes produced from transportation and packaging stages in logistics area. For this, survey questionary was constructed with five specific areas - strategy, transportation & distribution, custody, packaging, and information. Based on the 148 returned survey questionaries, this study analyzed 52 categories and finally suggests necessary modal shift, collaboration & co-operation in logistics, LCA(life-cycle assessment), and other promoting policies for the environment-conscious logistics in effective way.

• 대한환경공학회지
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• 제31권8호
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• pp.679-689
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• 2009

플라스틱에서부터 의약품에 이르기까지 대부분 일상 제품의 핵심적 기초 원료가 되는 경질올레핀은 한 국가의 경제규모와 성장을 예측할 수 있는 중요한 지표이다. 이러한 경질올레핀을 생산하는 NCC (Naphtha Cracking Center) 기술은 석유 관련 기간산업 중에서 가장 많은 에너지를 소비하는 공정으로 다량의 $CO_2$를 발생 시킨다. 본 연구에서는 다량으로 방출되는 $CO_2$를 감축, 저감시킬 수 있는 새로운 NCC 공정의 기술 수준과 개발 현황 및 기술 적용 가능성을 검토하였으며, 새로운 기술이 적용될 경우 $CO_2$ 저감 효과 및 그에 따른 탄소배출권, 그리고 에너지 절감양 등을 정량적으로 산출 하였다. 그 결과 고급 NCC 기술을 적용하면 기존 NCC 공정의 총 에너지 소비량의 약 35%를 줄일 수 있어 연간 약 330만톤의 $CO_2$ 감축과, 약 1,280억원의 탄소배출권 및 중유 약 152만 kL를 줄일 수 있다. 또한 촉매 접촉 분해 기술을 적용하면 연간 최대 약 380만톤의 $CO_2$를 저감할 수 있고 1,470억원 규모의 탄소배출권 및 약 174만 kL의 중유 소비를 줄 일 수 있다.

• 환경정책연구
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• 제6권4호
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• pp.55-81
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• 2007

CGE모형을 이용하여 우리나라를 포함한 OECD 국가와 중국, 브라질 등 18개 국가를 대상으로 다양한 비율의 $CO_2$ 저감량이 할당되는 경우 그에 따라 예상되는 국가별 GDP손실액을 추정하고 그 결과를 이용하여 각국의 $CO_2$ 저감에 따른 총비용곡선, 한계비용곡선, 평균비용곡선의 형태를 비교하였다. 대다수 국가의 총비용곡선, 한계비용곡선 그리고 평균비용곡선은 우상 향하는 형태를 나타내었으나 국가별로 실행가능한 저감영역이 다르고 또 각 함수의 기울기와 절편 등이 다르게 나타났다. 향후 post-kyoto 온실가스감축 의무부담방안 협상 시 온실가스 저감에 따른 각국의 GDP손실액 유형을 고려하여 우리나라와 비슷한 패턴을 가지고 있는 국가들과 공동으로 의무부담방안을 모색하는 것이 필요하다.

• Journal of Korea Trade
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• 제25권2호
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• pp.58-74
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• 2021

Purpose - This paper research on the embodied carbon emission in Sino-Korea trade. It calculates and analyzes the carbon emission coefficient and specific carbon emissions in Sino-Korea trade from 2005 to 2014. Design/methodology - This paper conducted an empirical analysis for embodied carbon emission in Sino-Korea trade during the years 2005-2014, using a multi-region input-output model. First, direct and complete CO2 emission coefficient of the two countries were calculated and compared. On this basis, combined with the world input-output table, the annual import and export volume and sector volume of embodied carbon emission are determined. Then through the comparative analysis of the empirical results, the reasons for the carbon imbalance in Sino-Korea trade are clarified, and the corresponding suggestions are put forward according to the environmental protection policies being implemented by the two countries. Findings - The results show that South Korea is in the state of net trade export and net embodied carbon import. The carbon emission coefficient of most sectors in South Korea is lower than that of China. However, the reduction of carbon emission coefficient in China is significantly faster than that in South Korea in this decade. The change of Korea's complete CO2 emission coefficient shows that policy factors have a great impact on environmental protection. The proportion of intra industry trade between China and South Korea is relatively large and concentrated in mechanical and electrical products, chemical products, etc. These sectors generally have large carbon emissions, which need to be noticed by both countries. Originality/value - To the best knowledge of the authors, this study is the first attempt to research the embodied carbon emission of ten consecutive years in Sino-Korea Trade. In addition, In this paper, some mathematical methods are used to overcome the error problem caused by different statistical caliber in different databases. Finally, the accurate measurement of carbon level in bilateral trade will provide some reference for trade development and environmental protection.