• Journal of Climate Change Research
• /
• v.5 no.3
• /
• pp.219-230
• /
• 2014

In this study, greenhouse gas emission of magnesium industry was estimated and the reduction potential of the greenhouse gas emission was evaluated with reduction technologies. Default value of IPCC guideline was used to calculate the greenhouse gas emission and $SF_6$ alternatives were considered in reduction potential. Import of magnesium ingot was 22,806 ton in 2013, which will be expected to increase to 81,700 ton with 20% rate in 2020. Magnesium ingot was consumed to produce magnesium alloy in diecasting process. Recently, commercial production of crown magnesium and magensium plate began. Based on ingot consumption, $CO_2$ emission of domestic magnesium industry was estimated to 504,000 ton, which is about 0.79% of domestic industrial emissions. Reduction potential of diecasting process was estimated to 489,320 ton by changing SF6 to alternative gases such as HFC-134a, Novec-612. Emission factor of Tier 3 level should be developed to enhance the accuracy of greeenhouse gas emission of magnesium industry.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.45 no.2
• /
• pp.114-121
• /
• 2009

There are increased in using the bio-ethanol, as the carbon neutral attracts many researchers due to a reduction in carbon dioxide spotted as the global warming gas. A gasoline engine with 100% of the bioethanol was developed and used in Brazil already, but researches of using the bio-ethanol in diesel engines are lack. In this study, combustion tests with blend fuel of the gas oil and bio ethanol by 50% maximally due to a low cetane number of bio-ethanol were accomplished as a basic study of introduction of using the bioethanol in diesel engines. The result was that smoke emission was decreased with increase in proportion of the bio-ethanol, due to the increase of a amount of pre-mixed combustion with ignition delay. Although the amount of $CO_2$ is reduced according as the bio-ethanol is used(carbon neutral), the emission of $CO_2$ with increase in the proportion of the bio-ethanol was more increased due to lower a heat value of bio-ethanol than gas oil.

• 한국연소학회:학술대회논문집
• /
• 2005.10a
• /
• pp.141-147
• /
• 2005

LNG combustion characteristics of oxygen carrier particles were investigated in a batch type bubbling fluidized bed reactor. Three particles, NiO/bentonite, $NiO/NiAl_2O_4$, $CO_xO_y/CoAl_2O_4$, were used as oxygen carrier particles and LNG and air were used as reactants for reduction and oxidation, respectively. In the reducer, high gas conversion and high $CO_2$ selectivity were achieved for all three particles. In the oxidizer, NOx was not detected. The results of exhaust gas analysis showed that inherent $CO_2$ separation and NOx-free combustion are possible in the LNG fueled chemical-looping combustion system with NiO/bentonite, $NiO/NiAl_2O_4$ and $Ca_xO_y/CoAl_2O_4$ particles.

• Clean Technology
• /
• v.20 no.3
• /
• pp.212-217
• /
• 2014

In order to regenerate the sulfidated desulfurization sorbent, oxygen is used as the oxidant agent on the regeneration process. The small amount of oxygen un-reacted in regeneration process is flowed into direct sulfur recovery process. However, the reactivity for $SO_2$ reduction can be deteriorated with the un-reacted oxygen by various reasons. In this study, the deactivation effects of un-reacted oxygen contained in the off-gas of regeneration process flowed into direct sulfur recovery process of hot gas desulfurization system were investigated. Sn-Zr based catalysts were used as the catalyst for $SO_2$ reduction. The contents of $SO_2$ and $O_2$ contained in the regenerator off-gas used as the reactants were fixed to 5.0 vol% and 4.0 vol%, respectively. The catalytic activity tests with a Sn-Zr based catalyst were for $SO_2$ reduction performed at $300-450^{\circ}C$ and 1-20 atm. The un-reacted oxygen oxidized the elemental sulfur produced by $SO_2$ catalytic reduction and the conversion of $SO_2$ was reduced due to the production of $SO_2$. However, the temperature for the oxidation of elemental sulfur increased with increasing pressure in the catalytic reactor. Therefore, it was concluded that the decrease of reactivity at high pressure is occurred by catalytic deactivation, which is the re-oxidation of lattice oxygen vacancy in Sn-Zr based catalyst with the un-reacted oxygen on the catalysis by redox mechanism. Meanwhile the un-reacted oxygen oxidized CO supplied as the reducing agent and the temperature in the catalyst packed bed also increased due to the combustion of CO. It was concluded that the rapidly increasing temperature in the packed bed can induce the catalytic deactivation such as the sintering of active components.

• Journal of Korean Society for Atmospheric Environment
• /
• v.24 no.2
• /
• pp.189-195
• /
• 2008

We developed emission factors for alternative fuels used in cement industries in Korea and also estimated reduction in emissions of greenhouse gas (GHG) by the use of alternative fuels. Emission factors for GHG of waste tire, waste plastic, waste oil and RDF were estimated to be about 89, 78, 77 and 95 ton $CO_2$/TJ respectively. When compared with previous studies, most of the results showed similar trends. The calorific value estimation and elemental analysis for energy source were implemented in order to estimate the exact emission factors and the reduction of GHG emissions using alternative fuel. In the case of 'A' company, $CO_2$ emission from alternative fuels was about 4% lower than that of bituminous coal only. Also in case of company 'B', $CO_2$ emission from alternative fuels was about 1.4% lower than that of only bituminous coal. In Germany and Japan, alternative fuel is not regarded to be fuel consumption in cement industry. When applying this rule, the emission reductions were about 4.3% for company 'A' and 6.3% for company 'B'. The results of this study may be considered as a useful information for developing strategies in reducing GHG emissions.

• Journal of Construction Engineering and Project Management
• /
• v.1 no.1
• /
• pp.11-17
• /
• 2011

According to the United Nations Framework Convention on Climate Change (UNFCCC), many countries around the world have been concerned with reducing Greenhouse Gas (GHG) emissions. Reducing the level of building energy consumption is particularly important in bringing GHG down. Because of this, many countries including the US and the EU are enforcing energy-related policies. However, these policies are focused on management of single types of buildings such as public buildings and office buildings, instead of management on a national level. Thus, although various policies have been enforced in many countries, $CO_2$ management on a national level is still not an area of focus. Therefore, this study proposed a community-based $CO_2$ management process that allows government-led GHG management. The minimum unit of the community in this study is a plot, and the process consists of three steps. First, the current condition of the GHG emission was identified by plot. Second, based on the identified results, the GHG emission reduction target was distributed per plot by reflecting the weighted value according to (i) the target $CO_2$ reduction in the buildings in the standard year, (ii) region, and (iii) building usage and size. Finally, to achieve the allocated target reduction, building energy management was executed according to the properties of the building located on each plot. It can be expected that the proposed community-based $CO_2$ management process will enable government-level GHG management, through which environment-friendly building construction can be promoted.

• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.262-268
• /
• 2011

According to the United Nations Framework Convention on Climate Change (UNFCCC), many countries around the world have been concerned with reducing Greenhouse Gas (GHG) emissions. Reducing the level of building energy consumption is particularly important in bringing GHG down. Because of this, many countries including the US and the EU are enforcing energy-related policies. However, these policies are focused on management of single types of buildings such as public buildings and office buildings, instead of management on a national level. Thus, although various policies have been enforced in many countries, CO₂ management on a national level is still not an area of focus. Therefore, this study proposed a community-based CO₂ management process that allows government-led GHG management. The minimum unit of the community in this study is a plot, and the process consists of three steps. First, the current condition of the GHG emission was identified by plot. Second, based on the identified results, the GHG emission reduction target was distributed per plot by reflecting the weighted value according to (i) the target CO₂ reduction in the buildings in the standard year, (ii) region, and (iii) building usage and size. Finally, to achieve the allocated target reduction, building energy management was executed according to the properties of the building located on each plot. It can be expected that the proposed community-based CO₂ management process will enable government-level GHG management, through which environment-friendly building construction can be promoted.

• Korean Chemical Engineering Research
• /
• v.62 no.3
• /
• pp.225-232
• /
• 2024

The reduction of CO₂ emissions in the energy production sector, which accounts for 86.8% of total greenhouse gas emissions, is important to achieve carbon-neutrality. At present, 60% of total power generation in South Korea is coal and natural gas. Replacing fossil fuel with renewable energy such as wind and solar has disadvantages of unstable energy supply and high costs. Therefore, this study was conducted through the co-firing of natural gas, ammonia and hydrogen utilizing the natural gas combined cycle process. The results demonstrated reduction in CO₂ emissions and 34%~238% of the power production compared to using only natural gas. Case studies on mass fractions of natural gas, ammonia and hydrogen indicated that power production and NO_x emissions were inversely proportional to the ammonia ratio and directly proportional to the hydrogen ratio. This study provides guidelines for the use of various fuel mixtures and economic analysis in co-firing power generation.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.3D
• /
• pp.375-381
• /
• 2011

This study presents an analysis of $CO_2$ emission reduction effect on bus information system (BIS) which is operated to improve various services of bus transit such as rapid and on-time service. Although the Intergovernmental Panel on Climate Change (IPCC) released three methodological types of models for analyzing the amount of greenhouse gas reduction, this study used the Tier 3 method that is the most concrete one. A case study was performed to a 8.3 km section of Daejun-Chungjoo BIS system, and dataset required to the Tier 3 method was obtained from ITS-based surveillance systems. The study result showed that the reduction effect of $CO_2$ on BIS operation was yearly $39.45tCO_2/km$. Therefore, such effect can be potentially useful to a measurement of effectiveness (MOE) of BIS projects hereafter.

• Korean Chemical Engineering Research
• /
• v.50 no.6
• /
• pp.1008-1014
• /
• 2012

The amount of domestic carbon dioxide emissions is more than 600 million tons/year. The emitted $CO_2$ should be captured and stored, however, suitable storage sites have not been found yet. A lot of researches on the conversion of captured carbon dioxide to useful carbon source have been conducted. The purpose of this study is to convert stable carbon dioxide to useful resources using less energy. For this purpose reducing gas and metallic oxide (activator) are required. Hydrogen was used as reducing gas and cobalt ferrite was used as activator. Considering that activator has different physical properties depending on synthesis methods, activator was prepared by hydrothermal synthesis and solid method. Decomposition characteristics of carbon dioxide were investigated using synthesized powders. Temperature programmed reduction/oxidation (TPR/TPO) and thermogravimetric analyzer (TGA) device were used to observe the decomposition characteristics of carbon dioxide. Activator prepared by solid method with 5 and 10 wt% CoO content showed an excellent performance. In TGA experiments with samples prepared by the solid method, reduction by hydrogen was 29.0 wt% and oxidation by $CO_2$ was highest in 27.5 wt%. 95% of adsorbed $CO_2$ was decomposed with excellent oxidation-reduction behaviors.