• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.737-740
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• 2006

A cement which is used in construction and a concrete which is a hydration product of cement is considered anti-environmental materials because of lots of $CO_2$ emission in progress of producing and making them. But a concrete absorbs the $CO_2$ gas in atmosphere after hydration and in its lifetime. Based on Papadakis' theses, this research is carried on calculation of the $CO_2$ absorption quantity in concrete. Also, the emission of $CO_2$ was calculated by cement manufacture. As a result, It is said that the $CO_2$ which was emitted during cement manufacturing, was absorbed the 53% of emission quantity by the carbonation of concrete.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.58-64
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• 2007

As the concerns regarding global worming were increased, the pressure of greenhouse gas(GHG) emission reduction on mobile source was also increased. Carbon dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this $CO_2$ emission. Therefore automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. In this study, in order to investigate $CO_2$ emission characteristics from gasoline passenger cars(PC), which is the most dominant vehicle type in Korea, 106 vehicles were tested on the chassis dynamometer. $CO_2$ emissions and fuel efficiency were measured. The emission characteristics by displacement, gross vehicle weight, vehicle speed and CVS-75/vehicle speed mode were discussed. Test modes were vehicle speed modes and CVS-75 mode that have been used to develop emission factors and to regulate for light-duty vehicle in Korea. It was found that $CO_2$ emissions showed higher large displacement, heavy gross vehicle weight, low vehicle speed and CVS-75 mode than small displacement, light gross vehicle weight, high vehicle speed and vehicle speed mode, respectively. From these results, correlation between $CO_2$ emission and fuel efficiency was also determined. The results of this study will contribute to domestic greenhouse gas emissions calculation and making the national policy for climate change.

• Journal of the Korea Concrete Institute
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• v.21 no.1
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• pp.85-92
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• 2009

A concrete is considered unfriendly-environmental material because it uses cement which emits much $CO_2$ during producing process. However, a concrete absorbs $CO_2$ through carbonation process during service life. In this paper how much concrete absorbs $CO_2$ through carbonation was calculated using 1) concentration of carbonatable substances in concrete, 2) carbonated volume of concrete, 3) molecular weight of $CO_2$ based on references and the method was proposed. $CO_2$ emission from producing $1m^3$ concrete was calculated based on $CO_2$ emission datum of materials used in concrete. From using these methods that calculate $CO_2$ emission and absorption of concrete, assessment of $CO_2$ emission-absorption against a real apartment was conducted by subtracting absorption $CO_2$ according to service life from $CO_2$ emission in the process of making concrete. As a result, a ratio of absorption over emission of $CO_2$ through concrete carbonation according to service life 40, 60, 80 years was assessed about 3.65, 4.47, 5.18%. An objective of this study is to propose how to calculate emission - absorption of $CO_2$ from producing and using concrete. Although the result value, emission - absorption of $CO_2$, is 5.18% very low when the service life of an apartment is 80years, the value can be improved by reducing emission from using blended cement such as blast furnace slag or increasing replacement ratio of cement and increasing carbonated volume of concrete from expanding service life of a building. This study may be useful when $CO_2$ emission - absorption of concrete is evaluated in the further study.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.52-60
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• 2016

This study investigates and analyzes the total amount of energy consumption and $CO_2$ emission during the material manufacturing, transportation, construction, operation, and disposal phases of eight elementary school buildings in South Korea. Toward this ends, the hybrid LCA model is proposed. The life cycle energy consumption and $CO_2$ emission of eight case buildings are assessed using the hybrid LCA model with an assumption that the operation period is 40 years. As a result, the embodied(sum of the energy consumption in the material manufacturing, transportation and construction phases), operational and disposal energy were 2,279, 11,182, $228Mcal/m^2$, respectively, on average. The average embodied, operational, and disposal $CO_2$ emission were 604, 2,708, 60 kg-$CO_2/m^2$, respectively, on average. This result indicates that about 17% of life cycle energy (or $CO_2$ emission) is consumed in the material manufacturing, transportation and construction phases. Thus, it is necessary to consider the embodied energy and $CO_2$ emission to reduce the life cycle energy and $CO_2$ emission of school buildings. In addition, while the insulation standard of building have been provided based on the climate zone, energy consumption in operation phase still varied depending on the regions in this study. Thus, the insulation standard of building needs to be improved through considering the climate of regions in detail.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.86-92
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• 2011

In order to reduce dependence on the fossil fuels and $CO_2$ gas emission in farming activities, the government has pushed ahead with making the self-sufficiency of farming energy up 40% level in green villages. The objectives of this study are to survey the energy consumption of horticultural facilities or agricultural machineries, and to analyze the reduced $CO_2$ gas emission level from fossil fuel to bio-diesel fuel. For the implement of this study, it is necessary to analyze the energy consumption level in the various sector of farming activities, and available renewable energy sources should be selected. Annual total $CO_2$ gas emission in the tillage farming sector was analyzed as $5,667,258\;t-CO_2$ and that in the horticultural facilities occupied $4,932,607\;t-CO_2$, while the $CO_2$ gas emission level of diesel fuel was $3,105,707\;t-CO_2$, and that of the heavy oil showed $1,370,578\;t-CO_2$. The average $CO_2$ gas emission level of horticultural facilities in the country was analyzed as $29,418\;t-CO_2/ha$. Among the total energy consumption of agricultural machineries, tractor used 284,763kL, power tiller spent 221,314 kL, grain drier consumed 145,524kL and combine tractor expend 72,537kL. From the comparison of $CO_2$ gas emission level between fossil fuel and bio-diesel fuel for the horticultural facilities or agricultural machinery in G-City, Jeonbuk Province, the $CO_2$ gas emission level can be reduced by 7% through replacing the fuel from fossil to biodiesel.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.874-885
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• 2011

In this study, the urban $CO_2$ emission based on energy consumption (Coal, Petroleum, Electricity, and City Gas) in 16 provincial and metropolitan city governments in South Korea was evaluated. For calculation of the urban $CO_2$ emission, direct and indirect emissions were considered. Direct emissions refer to generation of greenhouse gas (GHG) on-site from the energy consumption. Indirect emissions refer to the use of resources or goods that discharge GHG emissions during energy production. The total GHG emission was 497,083 thousand ton $CO_2eq.$ in 2007. In the indirect GHG emission, about 240,388 thousand ton $CO_2eq.$ was occurred, as 48% of total GHG emission. About 256,694 thousand ton $CO_2eq.$ (52% of total GHG emissions) was produced in the direct GHG emission. This amount shows 13% difference with 439,698 thousand ton $CO_2eq.$ which is total national GHG emission data using current calculation method. Local metropolitan governments have to try to get accuracy and reliability for quantifying their GHG emission. Therefore, it is necessary to develop and use Korean emission factors than using the IPCC (Intergovernmental Panel on Climate Change) emission factors. The method considering indirect and direct GHG emission, which is suggested in this study, should be considered and compared with previous studies.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.41-49
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• 2011

The power plants are one of the GHG major source among the sectors of fossil fuel combustion, therefore information of its emission factors is very essential to the establishing control strategies for the greenhouse gas emissions. The $CH_4$ and $N_2O$ concentration from power plants were measured using GC-FID and GC-ECD. The results showed that $CH_4$ emission factor was 0.33 kg/TJ and $N_2O$ emission factor was 0.88 kg/TJ. The $CH_4$ and $N_2O$ emission factors developed in this study were compared with those for IPCC default value and other countries emission factors. The results showed that $CH_4$ emission factor was lower than IPCC default value and Finnish emission factor, but higher than Japanese emission factor. $N_2O$ emission factor was higher Japanese emission factor and IPCC default emission factor however lower than Finnish emission factor. More research is needed on our own emission factors of various energy-consuming facilities in order to stand on a higher position in international negotiations regarding the treaties on climate changes.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.132-140
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• 2012

Along with the increasing interest in environmental problems such as global warming, the South Korean government has established policies and regulations to reduce the amount of greenhouse gases, targeting a 30% reduction of $CO_2$ compared to business-as-usual levels by 2020. Thus, there have been many studies in construction field to control and reduce the amount of $CO_2$ emitted from buildings. $CO_2$ emission from the building construction could be obtained by using the life cycle assessment(LCA) methodology. In LCA, it is essential to have life cycle inventory(LCI) data of construction materials consisting of $CO_2$ emission data that have been defined and examined in a detailed way in order to obtain more accurate and detailed $CO_2$ emission of buildings. To date, however, the LCI data have been acquired only for the representative materials. Accordingly this study aimed to propose detailed $CO_2$ emission data for steel rebar and H-beam, which are the essential structural steel materials, by strength and type. To accomplish the objective, this study used Input-Output LCA methodology which is based on the Input-Output table. It is believed that the $CO_2$ emission data of steel materials acquired from this study would allow a more accurate assessment of $CO_2$ emission for diverse structural design alternatives.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.875-896
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• 2010

Using the difference in differences (DID) estimation method, this paper analyzes the effect of European Union's Emission Trading Scheme (EU ETS) on the reduction of per capita $CO_2$ emission among the twenty five participating countries. For this, the panel dataset of forty two European countries for the period 1990~2007 is constructed. Special attention is paid to the bias of the standard errors in the DID estimation due to the presence of serial correlation in the error terms. The results shows quite a robust effect of EU ETS on the reduction of per capita $CO_2$ emission among the participating countries regardless of the calculation methods of standard errors. The results also shows that the increased implicit tax rate on energy has a robust effect on the reduction of per capita $CO_2$ emission. On the contrary, the estimation results regarding the effects of per capita GDP and population density on the per capita $CO_2$ emission seem inconsistent. In particular, the environmental Kuznets curve is not statistically supported with the use of robust standard errors.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.59-60
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• 2012

This paper describes gas turbine combustion characteristics of synthetic gas which is mainly composed of hydrogen and carbon monoxide. The combustion characteristics such as combustion instability, NOx and CO emission, temperatures at turbine inlet, liner and dump plane, and flame structure were investigated when changing when changing $H_2:CO$ ratio, dilution ratio, and $CH_4:syngas$ ratio. From the results, quantitative relationships are derived between key aspects of combustion performance, notably NOx emission. It is concluded that NOx emission of syngas is strongly influenced by the diluent heat capacity and combustion instability. Moreover, NOx control method using diluents such as $N_2$, $CO_2$, steam is verified.