• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.294-299
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• 2012

Rail transport has been considered an environmental-friendly transport mode compared with other transport modes such as ship, truck, and aircraft. However, air pollutions emitted by diesel locomotives have emerged as social issues. In addition, the railway industry may not be able to avoid a duty of alleviating greenhouse gases emission owing to the Korean government policies for green growth which is an economic paradigm that simultaneously pursues growth and environmental improvement. Moreover, rising oil prices has burdened a train operating company. The purpose of this paper is to develop a methodology of determining an economical speed of diesel freight locomotive from the viewpoint of the train operating company. In the methodology, we first define an operational cost function based on various cost factors and then suggest formula to calculate an economical speed of diesel freight locomotive. To estimate the influence of cost factors such as diesel price, carbon taxes, and time costs on the speed of diesel freight locomotive, sensitivity analysis was conducted.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.269-297
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• 2021

Bioplastics are attracting attention as a substitute for conventional petroleum-based plastics because they are carbon neutral and can be biodegradable. This study estimated economic and environmental impact of regulating the petroleum-based plastics industry and fostering the bioplastics industry using a Recursive Dynamic CGE Model of the Korean Economy. Results show that the regulation of the conventional plastics industry exhibits a positive environmental impact by reducing greenhouse gases and plastic waste and a negative economic impact with a decrease in GDP. Meanwhile, fostering the bioplastics industry with regulation on conventional plastics industry has similar levels of greenhouse gas and waste reduction effects when there is only regulation on the conventional plastics industry. It is also shown that expanding the production of bioplastics industry offsets existing economic losses as a form of increased GDP. If petroleum-based plastics are replaced through the expansion of bioplastics production, it can contribute to the decoupling of greenhouse gas emissions and plastic waste from economic growth.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.119-125
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• 2023

It is necessary to reduce aviation GHG(CO2) emission to ensure aviation sustainable development. Operational improvements may not contribute significantly to carbon reduction but it can sustatially reduce emission in a short term. ICAO has developed GANP and ASBU to optimize operations and countries are making efforts to expand infrastructure and develop technology. The legal barriers to operational improvement are based on the notion of state sovereignty under the Chicago Convention which allows countries to control inefficiencies based on borders or limit or prohibit the passage of aircraft. Chicago Convention does not grant unlimited freedom of air sovereignty and if the concept of state sovereignty is interpreted according to the times it is possible to achieve smooth operational improvement.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1403-1411
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• 2023

Carbon dioxide (CO₂) is the most abundant component of greenhouse gases (GHGs) and directly creates environmental issues such as global warming and climate change. Carbon capture and storage have been proposed mainly to solve the problem of increasing CO₂ concentration in the atmosphere; however, more emphasis has recently been placed on its use. Among the many methods of using CO₂, one of the key environmentally friendly technologies involves biologically converting CO₂ into other organic substances such as biofuels, chemicals, and biomass via various metabolic pathways. Although an efficient biocatalyst for industrial applications has not yet been developed, biological CO₂ conversion is the needed direction. To this end, this review briefly summarizes seven known natural CO₂ fixation pathways according to carbon number and describes recent studies in which natural CO₂ assimilation systems have been applied to heterogeneous in vivo and in vitro systems. In addition, studies on the production of methanol through the reduction of CO₂ are introduced. The importance of redox cofactors, which are often overlooked in the CO₂ assimilation reaction by enzymes, is presented; methods for their recycling are proposed. Although more research is needed, biological CO₂ conversion will play an important role in reducing GHG emissions and producing useful substances in terms of resource cycling.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.77-84
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• 2016

In 2012, total GHG emissions in transport sector reached 88 Million ton CO2eq. The emissions generated in the road accounted for 94% of the transport sector. Currently, there are many efforts to operate an education and campaign for eco-driving. However study for eco-friendly vehicle control considering road alignment is limited. Therefore, the purpose of this study is to address fuel-efficient driving strategy in horizontal curve section. To fulfill the goal, designed ideal freeway horizontal curve road follows regulations about road structure. And safety speed is calculated for considering vehicle's safety on horizontal curve road. Authors composed the acceleration and deceleration scenario for each horizontal curve section and generated the speed profiles that are limited by the safety speed. Speed profiles are converted into force that horizontal curve affect to fuel consumption. Then, we calculated fuel consumption using Comprehensive Modal Emission Model. Then, we developed eco-driving strategy by selecting most fuel-efficient scenario. To validate this strategy, we selected study site and compared fuel consumption for eco and manual driving. As the result, fuel consumption when driver used eco-driving was lessened by 20.73% than that of manual driving.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.160-167
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• 2018

The role played by reservoirs in the biogeochemical cycles of elements is a subject of ongoing debate. Recent research has revealed that reservoirs emit significant levels of greenhouse gases. To assess the importance of reservoirs in monsoon climate areas as a source of methane gas into the atmosphere, we investigated variations in organic carbon (OC) input into the reservoir, oxic state changes, and finally the amount of methane emitted (focusing on the ebullition pathway) in Lake Soyang, which is the largest reservoir in South Korea. Total organic carbon (TOC) concentrations were higher during summer after two years of heavy rainfall. The sedimentation rates of particulate organic carbon (POC) and particulate organic nitrogen (PON) were higher in the epilimnion and hypolimnion than the metalimnioin, indicating that autochthonous and allochthonous carbon made separate contributions to the TOC. During stratification, oxygen depletion occurred in the hypolimnion due to the decomposition of organic matter. Under these conditions, $H_2S$ and $CH_4$ can be released from sediment. The methane emissions from the reservoir were much higher than from other natural lakes. However, the temporal and spatial variations of methane ebullition were huge, and were clearly dependent on many factors. Therefore, more research via a well-organized field campaign is needed to investigate methane emissions.

• Resources Recycling
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• v.32 no.3
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• pp.45-56
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• 2023

This study analyzed the economic and environmental effect of recycling rhodium used in the non-catalytic field. As an analysis methodology, economic effect analysis applied cost-benefit analysis and resource-saving effect analysis and the environmental effect analysis applied life cycle assessment (LCA). The results show that from an economic point of view, the cost-benefit ratio was 1.28, which was feasible, and the cost reduction was 237,000 won based on 1 g of rhodium recycled and the amount of rhodium recycled was 7.17 billion won in 2025. As for the environmental effect, the greenhouse gas(GHG) emissions were compared between the case of recycling based on rhodium 1 kg and the case of overseas sales. The calculation results show that based on rhodium 1 kg, greenhouse gas emissions were reduced by 99.8%, from 65 kg CO₂eq./kg-Rh when recycling to 28,800 kg CO₂eq. when sold overseas. The results obtained from this study could suggest that rhodium recycling is necessary in Korea where resources are scarce by analyzing the economic and environmental effect of recycling rhodium used in the non-catalytic field.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.450-458
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• 2012

In order to reduce the effects of greenhouse gas (GHG) emissions, the South Korean government has announced a special platform of technologies as part of an effort to minimize global climate change. To further this effort, the Korean government has pledged to increase low-carbon and carbon neutral resources for biofuel derived from biomass to replace fossil and to decrease levels of carbon dioxide. In general, second generation biofuel produced form woody biomass is expected to be an effective avenue for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in road transport. It is important that under the new Korean initiative, pilot scale studies evolve practices to produce biomass-to-liquid (BTL) fuel. This study reports the quality characteristics of F-T(Fischer-Tropsch) diesel for production of BTL fuel. Synthetic F-Tdiesel fuel can be used in automotive diesel engines, pure or blended with automotive diesel, due to its similar physical properties to diesel. F-T diesel fuel was synthesized by Fischer-Tropsch (F-T) process with syngas($H_2$/CO), Fe basedcatalyst in low temperature condition($240^{\circ}C$). Synthetic F-T diesel with diesel compositions after distillation process is consisted of $C_{12}{\sim}C_{23+}$ mixture as a kerosine, diesel compositions of n-paraffin and iso-paraffin compounds. Synthetic F-T diesel investigated a very high cetane number, low aromatic composition and sulfur free level compared to automotive diesel. Synthetic F-T diesel also show The wear scar of synthetic F-T diesel show poor lubricity due to low content of sulfur and aromatic compounds compared to automotive diesel.

• KDI Journal of Economic Policy
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• v.34 no.2
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• pp.55-93
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• 2012

In Korea, energy policies are actualized through various energy-related plans. Recently, however, as high-ranking plans, which are very vision-oriented, continually set higher sector-by-sector goals, subordinate action plans, which require consistency, encounter distortions in their establishment process. Also, each subordinate action plan reveals limitations in terms of securing flexibility of the plan in responding to uncertainties of the future. These problems pose potential risks such as causing huge social costs. In this regard, with an aim to provide empirical evidence for discussions on improving the procedure for developing and executing Korea's energy plans, this study mainly analyzes the Basic Plan on Electricity Demand and Supply-one of the most important subordinate action plans-in order to explain the problems of the Basic Plan in a logical manner, and potential problems that could occur in the process of sustaining consistency between the Basic Plan and its higher-ranking plans. Further, this paper estimates the scale of social costs caused by those problems assuming realistic conditions. According to the result, in the case of where maximum electric power is estimated to be 7% (15%) less than the actual amount in the Basic Plan on Electricity Demand and Supply, the annual generation cost will rise by 286 billion won and (1.2 trillion won) in 2020. Such social costs are found to occur even when establishing and executing the Basic plan according to the target goal set by its higher-ranking plan, the National Energy Master Plan. In addition, when another higher-ranking GHG reduction master plan requires the electricity sector to reduce emissions by additional 5% in the GHG emissions from the right mix in electricity generation with 'zero' cost of carbon emission, the annual generation cost will rise by approximately 915 billion won in 2020. On the other hand, the analysis finds that since economic feasibility of electric powers in Korea varies significantly depending on their type, Korea is expected to face very small potential social costs caused by uncertainties over the future price of carbon dioxide in the process of establishing the Basic Plan.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.399-407
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• 2008

Importance of climate change and its impact on agriculture and environment has increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which had caused an increase of temperature in Earth. Greenhouse gas emissions such as methane($CH_4$) and nitrous oxide($N_2O$) in the field need to be assessed. GHGs fluxes using chamber systems in the fields(2004~2005) with pepper cultivation were monitored at the experimental plots of National Academy of Agricultural Science(NAAS), Rural Development Administration(RDA) located in Suwon city. $N_2O$ emission during pepper growing period was reduced to 74.0~82.1% in sandy loam soil compared with those in clay loam soil. Evaluating $N_2O$ emission at different levels of soil water conditions, $N_2O$ emission at -50 kPa were lowered to 13.2% in clay loam soil and 40.2% in sandy loam soil compared with those at -30 kPa. $CH_4$ emission was reduced to 45.7~61.6% in sandy loam soil compared with those in clay loam soil. Evaluating $CH_4$ at different levels of soil water conditions, $CH_4$ emission at -50 kPa was lowered to 69.6% in clay loam soil and 55.8% in sandy loam soil compared with those at -30 kPa. It implied that -50 kPa of soil water potential was effective for saving water and reducing GHG emissions. From the path analysis as to contribution factors for $N_2O$ emission, it appeared that contribution rate was in the order of mineral N(51.2%), soil temperature (25.8%), and soil moisture content(23.0%) in clay loam soil and soil moisture content(39.3%), soil temperature (36.4%), and mineral N(24.3%) in sandy loam soil.