• New & Renewable Energy
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• v.16 no.4
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• pp.9-22
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• 2020

This study analyzed the short- and long-term effects of nuclear and renewable energy generation on CO2 emissions in Korea, Japan, and Germany from 1987 to 2016 by using the unit root test, Johansen cointegration test, and ARDL model. The unit root test was performed, and the Johansen cointegration test showed cointegration relationships among variables. In the long run, in Germany, the generation of both nuclear and renewable energy was found to affect CO2 emission reduction, while South Korea's renewable energy generation, including hydropower, increased the emissions. Japan only showed significance in fossil fuels. In the short run, in the three countries, the generation of nuclear and renewable energy, excluding hydropower, affected CO2 emission. However, in Korea and Germany, nuclear and renewable energy generation, respectively, affected CO2 emission reduction. Although the rest are significant, the results showed that they increased CO2 emissions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.95-105
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• 2009

Land Use Changes (LUCs) have effects on greenhouse gas emissions and carbon stocks in soil and vegetation. Therefore, predictions for LUC are very important for achieving quantitative targets of $CO_2$ reduction rates. Some research exists on carbon fluxes and carbon cycles to estimate carbon stocks in terrestrial ecosystems in Korea. However, these researches have limitations in terms of helping us understand future potential reductions of $CO_2$ that reflect the influence of LUC. The aim of this study is to analyze the reduction levels of $CO_2$ emissions while considering LUC scenarios that effect carbon fluxes for LCS basic study in the year 2030. In this study, a common approach to model the effects of LUC on carbon stocks is the use of CA-Markov technical process with LUC patterns in the past. Potential reduction of $CO_2$ is calculated by change of land use that contains different soil organic carbon, each land use type, and biomass in vegetation. An IPCC analytical method of natural carbon sink and coefficient results from previous study in Korea is used as a calculation method for potential reduction of $CO_2$. As a result, 12,419 KtC will be reduced annually, which is 8.3% percent of 2005 $CO_2$ emissions in Korea. This will result in 3,226 hundred million won of economic efficiency. In conclusion, conservation of natural carbon sinks is necessary even if the amount of potential reduction change is little.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.5
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• pp.405-415
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• 2007

The effects of recirculated exhaust gas on exhaust emissions under four kinds of nozzle tip with the different fuel consumption rates are experimentally investigated by using an once-through boiler with a FGR system. The purpose of this study is to develop the FGR control system for reducing $NO_x$ emissions in boilers. Intake and exhaust oxygen concentrations, and equivalence ratio are considered to figure out the effect of FGR rate on exhaust emissions at various fuel consumption rates. It is found that $NO_x$ emissions are markedly decreased, while soot emissions are increased owing to the drop of intake and exhaust oxygen concentrations, and the rise of equivalence ratio as FGR rates are elevated. One can also conclude that the reduction in $NO_x$ emissions is more considerably influenced by the variation of equivalence ratio due to the FGR rate than the fuel consumption rate.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.188-194
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• 2005

The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments were performed at various engine loads while the EGR rates were set from $0\%$ to $30\%.$ The emissions trade-off and combustion of diesel engine are investigated. The brake specific fuel consumption rate is very slightly fluctuated with EGR in the range of experimental conditions. The ignition delay increased with increasing EGR rate. The maximum value of premixed combustion for the rate of heat release is increased with increasing EGR rate. NOx emissions are decreased with increasing EGR rate at high load and high speed. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions.

• Environmental Engineering Research
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• v.21 no.1
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• pp.91-98
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• 2016

Along with China's increasing share in global total $CO_2$ emissions, there is a necessity for China to shoulder large emission-mitigating responsibility. The appropriate allocation of $CO_2$ emission quotas can build up a solid foundation for future emissions trading. In views of originality, an optimized approach to determine $CO_2$ emissions allocation efficiency based on the zero sum gains data envelopment analysis (ZSG-DEA) method is proposed. This paper uses a non-radial ZSG-DEA model to allocate $CO_2$ emissions between different Chinese provinces by 2020 and treats $CO_2$ as the undesirable output variable. Through the calculation of efficiency allocation amounts of provincial $CO_2$ emissions, all provinces are on the ZSG-DEA efficiency frontier. The allocation results indicate that the cumulative optimal amounts of $CO_2$ emissions in 2020 were higher than the actual amounts in 13 provinces, and lower in other 17 provinces, and show that different provinces have to shoulder different mitigation burdens in terms of emission reduction.

• Korea Trade Review
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• v.44 no.1
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• pp.45-56
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• 2019

The purpose of this study is to investigate the relationship between foreign investment and carbon emissions in the Korean electricity sector, the causal relationship between the foreign investment invested in the electric power sector in the 16 regional regions and the carbon emissions in the region, The purpose of this study is to analyze the effects of foreign investment on these sectors and the carbon footprint of these sectors using Panel Random Effect Analysis, Panel VAR and OLS models. A panel analysis of foreign investment and regional carbon emissions showed that there was a causal relationship. Based on this analysis, OLS analysis showed that 7 out of 16 metropolitan areas were foreign investment And carbon emissions were significant. In the remaining six regions except Gwangju, there was a causal relationship between foreign investment in the local power sector and the reduction of carbon emissions. After categorizing the electric power industry by device, process, purpose and number of employees, causality also appeared in relation to foreign investment in these sectors and their carbon emissions. Through this study, the authors suggest that foreign investment can be a way to solve not only the financial burden of carbon emission problem, but also the development of national economy and industry through the inflow of capital and advanced new technology.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.597-617
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• 2022

In this study, consumption-based greenhouse gas emissions from 1990 to 2021 are calculated by the industry sector, and greenhouse gas emissions transferred due to trade between countries are compared to analyze what implications Korea has. As a result, production-based and consumption-based emissions in the United States, Germany, the EU, and the OECD are gradually decreasing. Production-based emission in Korea is larger than consumption-based emissions because Korean economic structure is import-oriented. However, unlike other developed countries, Korea cannot trade energy by land, so it can be said that it is reasonable to establish a greenhouse gas reduction plan considering Korea's unique characteristics.

• International Journal of Automotive Technology
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• v.5 no.4
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• pp.311-319
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• 2004

There are many methods to test engine emissions depending on the regulations used such as FTP-75(CYS-75) mode, 10-15 mode and ECE-15 mode. Most of these modes consist of transient conditions such as cranking, rapid acceleration or deceleration modes. In this experimental research, the transient characteristics including cranking and accelerating mode in SI engines were studied to compare pure gasoline with methanol-reformulated fuels for performance and exhaust emissions. The results show that methanol-reformulated fuels have a better emissions reduction rate than that of pure gasoline especially for HC, CO and NOx emissions during cranking mode. The acceleration performances conform to the results of the distillation curve and the CO concentration for RM50 varies slightly in acceleration mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.22-30
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• 2003

Engine-out HC emissions were investigated during cold and hot start. The tests were conducted according to engine cooling temperatures which were controlled by simulated coolant temperatures of cold and hot start, on a 1.5L, 4-cylinder, 16 valve, multipoint-port-fuel-injection gasoline engine. Real time engine-out HC emissions were measured at a exhaust port and cylinder head using Fast Response Flame Ionization Detector(FRFID). Unburned hydrocarbons emitted at the cold coolant temperature were much higher than those of the hot coolant temperatures. And the main source of the high HC emission was confirmed as misfire at cold coolant temperature. In addition, the effect of intake valve timing on engine-out HC emissions was investigated. The results obtained indicate that optimized intake phasing provides the potential for start-up engine-out HC emissions reduction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1123-1133
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• 2015

This study proposed an evaluation method of mobile emissions reduction strategies for air quality management. The proposed method was considered Travel Demand Model (TDM) and Analytic Hierarchy Process (AHP), while an existing method was focused on quantitative factors. AHP of the evaluation indices of mobile emissions reduction strategies show that quantitative evaluation indices such as air pollutants and greenhouse gas reduction are more important than the political evaluation indices (Consistency with an upper plan, Policy applicability, Technical applicability and feasibility) and each weight of air pollutants and greenhouse gas reduction are found to be 0.373 and 0.218. The early scrapping policy of decrepit diesel vehicle is the best policy in the proposal method using TDM and AHP but this result differs from evaluated result by TDM or AHP respectively. These results are limited to the basic assumption and range of reduction scenarios but are expected to contribute to establish more reasonable and effective mobile emission reduction strategies.