• Journal of Hydrogen and New Energy
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• v.34 no.4
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• pp.327-333
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• 2023

The water gas shift reaction was carried out using the commercial catalyst pellet and the simulated gases expected to occur from waste plastic gasification. In the water gas shift reaction, the high temperature shift reaction and the low temperature shift reaction were continuously performed with CO:H₂O ratio of 1:2, 1:2.5, and 1:3, and the CO conversion and H₂ increase rate were evaluated. The H₂ increase rate increased in order to CO:H₂O ratio of 1:3 > CO:H₂O ratio of 1:2.5 > CO:H₂O ratio of 1:2. The CO conversion showed a high value of more than 97% at each CO:H₂O ratio. The water gas shift reaction at a CO:H₂O ratio of 1:3 showed the highest H2 increase rate and CO conversion.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.169-177
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• 2020

Here, the stability of stainless steel 316 (SS-316) was investigated to identify its applicability in the oxide reduction process, as a component in related equipment, to produce a complicated gas mixture composed of O₂ and Cl₂ under an argon (Ar) atmosphere. The effects of the mixed gas composition were investigated at flow rates of 30 mL/min O₂, 20 mL/min O₂ + 10 mL/min Cl₂, 10 mL/min O₂ + 20 mL/min Cl₂, and 30 mL/min Cl₂, each at 600℃, during a constant argon flow rate of 170 mL/min. It was found that the corrosion of SS-316 by the chlorine gas was suppressed by the presence of oxygen, while the reaction proceeded linearly with the reaction time regardless of gas composition. Surface observation results revealed an uneven surface with circular pits in the samples that were fed mixed gases. Thermodynamic calculations proposed the combination of Fe and Ni chlorination reactions as an explanation for this pit formation phenomenon. An exponential increase in the corrosion rate was observed with an increase in the reaction temperature in a range of 300 ~ 600℃ under a flow of 30 mL/min Cl₂ + 170 mL/min Ar.

• Journal of Environmental Impact Assessment
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• v.21 no.2
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• pp.255-264
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• 2012

The present study attempts to understand the emission pattern of greenhouse gases in people's daily life through the estimation and analysis of the amount and characteristics of the greenhouse gases. Based on the survey of 1,000 people throughout the nation, monthly emission of greenhouse gases per-capita was estimated from their use of fuels, electricity, water, and personal and public transportation means in addition to their waste generation. In the case of personal car drivers, greenhouse gas emission was the greatest from their cars, followed by the emission from electricity, fuels, and public transportation. Emission from water consumption and waste generation was relatively low. Fuel consumption varied depending on the number of household members, their housing type, and the size of their living spaces. Results showed that single-person households emitted the largest amount of per-capita greenhouse gas while greenhouse gas emission from electricity was inversely proportional to the number of persons in a given household.

• Advances in Energy Research
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• v.3 no.3
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• pp.167-179
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• 2015

This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.153-154
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• 2017

The thermal analysis of transportation and storage cask for SNF was conducted during short term loading operations for forced gas drying condition. The fuel cladding temperature in 6 regions of SNF in the cask during the short term loading operations for forced gas drying condition is shown in the Fig. 3. The thermal analysis results of calculated maximum cladding temperature in each process demonstrate that operating scenario of TFD in detailed design maintain well below the temperature limits of $400^{\circ}C$.

• Clean Technology
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• v.19 no.2
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• pp.113-120
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• 2013

The treatment of chemically stable perflourocompounds (PFCs) requires a large amount of energy. An energy efficient arc plasma system has been developed to overcome such disadvantage. $CF_4$, $SF_6$ and $NF_3$ were injected into the plasma torch directly, and net plasma power was estimated from the measurement of thermal efficiency of the system. Effects of net plasma power, waste gas flow rate and additive gases on the destruction and removal efficiency (DRE) of PFCs were examined. The calculation of thermodynamic equilibrium composition was also conducted to compare with experimental results. The average thermal efficiency was ranged from 60 to 66% with increasing waste gas flow rate, while DRE of PFCs was decreased with increasing gas flow rate. On the other hand, DRE of each PFCs was increased with the increasing input power. Maximum DREs of $CF_4$, $SF_6$ and $NF_3$ were 4%, 15% and 90%, respectively, without reaction gas at the fixed input power and waste gas flow rate of 3 kW and 70 L/min. A rapid increase of DRE was found using hydrogen or oxygen additional gases. Hydrogen was more effective than oxygen to decompose PFCs and to control by-products. The major by-product in the arc plasma process with hydrogen was hydrofluoric acid that is easy to be removed by a wet scrubber. DREs of $CF_4$, $SF_6$ and $NF_3$ were 25%, 39% and 99%, respectively, using hydrogen additional gas at the waste gas flow rate of 100 L/min and the input power of 3 kW.

• Asian Journal of Atmospheric Environment
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• v.2 no.2
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• pp.116-124
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• 2008

In this study, the Tier 2 method recommended by the Intergovernmental Panel on Climate Change (IPCC) was used to predict the methane generation rate at two landfill sites, designated as Y and C for purposes of this study, in South Korea. Factors such as the average annual waste disposal, methane emissions ($L_0$) and methane gas generation rate constant (k) were estimated by analyses of waste and the historical data for the landfills. The value of k was estimated by field experiments and then the changes in the methane generation rate were predicted through the year 2050, based on the value of k. The Y landfill site, which was in operation until the year 2008, will generate a total of 17, 198.7 tons by the end of 2018, according to our estimations. At the C landfill site, which will not be closed until the end of 2011, the amount of methane gas generated in 2011 will be 3,316 tons and the total amount of gas generated by 2029 will be 61,200 tons. The total production rate of methane gas at the C landfill is higher than that of the Y landfill. This indicates that the capacity of a landfill site affects the production rate of methane gas. However, the interrelation between the generation rate of methane and the value of k is weak. In addition, the generation of methane gas does not cease even when the operations at a landfill site come to a close and the methane gas production rate is at its highest at end of the operating life of a landfill site.

• Resources Recycling
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• v.20 no.2
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• pp.3-15
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• 2011

Current, Registration fields of CDM projects are being conducted in a variety of parts such as mostly energy, chemical processing and manufacturing processes. However, there are not many CDM project registrations by recycling of inorganic waste. In this paper, analysis abroad CDM project and applications in order to review possibility of CDM project registration through the recycling of domestic inorganic waste were investigated. As a results, registered case of CDM project by inorganic waste recycling was researched to registrate in raw material alternative field of cement industry that inorganic waste can be used in large quantities. Application prospects of CDM project in Korea will be possible to analysis industrial scale, industry using inorganic raw materials, green house gas emissions and inorganic waste generated in large quantities.

• Journal of Wellbeing Management and Applied Psychology
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• v.7 no.3
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• pp.31-42
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• 2024

Purpose: Open-air dumping is a significant problem in Gilgit City, with limited research analyzing waste generation and its physicochemical impact on the soil. This study aimed to evaluate the effects of open dumping on soil properties and compare them with a controlled site. Research Design, data, and Methodology: Using ANOVA, the study found significant differences in electrical conductivity (EC), soil organic matter (SOM), soil organic carbon (SOC), sand, silt, and clay between the two sites, except for pH. Pearson correlation revealed that pH negatively correlated with EC, sand, and silt, but positively with SOM, SOC, and clay. The control site's mean EC was 6.06 mS/m, whereas the dumping site recorded 8.5 mS/m. EC is inversely related to SOM, SOC, silt, and clay, but directly to sand. SOC and SOM values varied significantly, with notable differences in soil texture components like clay and silt. Results: The research highlights the detrimental effects of unsystematic waste dumping on soil health and its contribution to greenhouse gas emissions, particularly methane, which exacerbates climate change. Conclusion: The study concluded that waste deposition and decomposition significantly impact EC, SOM, SOC, and soil texture, though pH remains unchanged. The unsystematic dumping of solid waste contributes to climate change through methane production, a potent greenhouse gas. To mitigate these impacts, the study recommends regular monitoring, waste prevention, recycling strategies, and continuous training for stakeholders to achieve sustainable development.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.136-140
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• 2010

The integrated gasification combined cycle (IGCC) is one of the most promising proposed processes for advanced electric power generation that is likely to replace conventional coal combustion. This emerging technology will not only improve considerably the thermal efficiency but also reduce or eliminate the environmentally adverse effects normally associated with coal combustion. The IGCC process gasifies coal under reducing conditions with essentially all the sulfur existing in the form of hydrogen sulfide ($H_2S$) in the product fuel gas. The need to remove $H_2S$ from coal derived fuel gases is a significant concern which stems from stringent government regulations and also, from a technical point of view and a need to protect turbines from corrosion. The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream. The sulphidation of waste seashells with $H_2S$ was studied in a thermogravimetric analyzer at temperature between $600^{\circ}C$ and $800^{\circ}C$. The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affects the $H_2S$ removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electronmicroscopy.