• 자원리싸이클링
• /
• 제14권1호
• /
• pp.39-46
• /
• 2005

본 연구에서는 고상폐기물(소각재) 처리를 위해 중간 전극 (IEI, Inter-Electrode Insert)이 있는 button 형태의 고형 체형 고출력 토치를 개발하였고 폐기물처리 플라즈마설비에 적용하여 운전특성을 얻었다. 본 연구의 토치 실험 결과 비이송형 모드에서는 가스량의 증가에 따라 전압이 증가하였고, 이송형 모드에서는 가스량 변화에는 영향이 없었으나 토치와 바닥면과의 거리, 슬래그의 성분 그리고 용융 슬래그의 체적에 따라 전압의 변화가 발생하였다. 특히 아크전압이 슬래그내의 total Fe 함량이 10% 내외에서 안정적으로 유지되었으며, 전기전도도 계산결과 0.05~0.25${\Omega}^{-1}cm^{-1}$ 범위로 나타났다. 본 연구의 토치 효율은 75~85%로 나타났으며, 마모율은 2${\times}10^{-6}~6{\times}10^{-6}$ kg/s의 범위로 나타났다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 춘계학술대회
• /
• pp.523-526
• /
• 2006

The target of this work was the process development of demonstration plant to produce the high quailty alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70t/y and the pi lot plant of 360 t/v had been developed. Main research contents in this step were the process performance test of pilot plant ot 360ton/year and the development of demonstration plant of 3 000 t/y which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/v showed components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

• Bulletin of the Korean Chemical Society
• /
• 제22권1호
• /
• pp.19-24
• /
• 2001

A solvent sublation has been studied for the determination of trace Au(III), Pt(IV) and Pd(II) in waste water with their complexes of 2-mercaptobenzothiazole (MBT). Experimental conditions such as the concentration of HCl, the amount of MBT as a ligand, the type and amount of surfactants, bubbling rate and time, and the type of organic solvent were optimized for the solvent sublation, i.e., 25.0 mL of 2.0 M HCl solution and 30mL of 0.4%(w/v) MBT ethanolic solution were added to a 1.0 L sample to form stable complexes. The addition of 4.0 mL of 1 ${\times}$$10^{-3}$ M CTAB (cetyltrimehtylammonium bromide) solution was needed for the effective flotation accomplished by bubbling nitrogen gas at the rate of 40.0 mL/min for 35 minutes. As a solvent, 20.0 mL of MIBK (methylisobuthylketone) was used to extract the floated complexes. The procedure was applied to three kinds of waste waters. Au(III) was determined as 0.68 ng/mL and 0.98 ng/mL respectively for final washed water of two plating industries in Banwol. Pd(II) and Pt(IV) were not detected in any of the three samples. The recovery, which was obtained with analyte-spiked samples, were 95-120%.

• 방사성폐기물학회지
• /
• 제19권2호
• /
• pp.205-214
• /
• 2021

Currently, the interim storage pools of spent fuels in South Korea are expected to become saturated from 2024. It is required to prepare an operation plan of a domestic dry storage facility during a long-term period, with the researches on safety evaluation methods. This study modified the FRAPCON code to predict the spent fuel integrity evaluation such as the axial cladding temperature, the hoop stress and hydrogen distribution in dry storage. The cladding temperature in dry storage was calculated using the COBRA-SFS code with the burnup information which was calculated using the FRAPCON code. The hoop stress was calculated using the ideal gas equation with spent fuel information such as rod internal pressure. Numerical analysis method was used to calculate the degree of hydrogen diffusion according to the hydrogen concentration and temperature distribution during a dry storage period. Before 50 years of dry storage, the cladding temperature and hoop stress decreased rapidly. However, after 50 years, they decreased gradually and the cladding temperature was below 400 K. The initial temperature distribution and hydrogen concentration showed a parabolic line, but hydrogen was transferred by the hydrogen concentration and temperature gradient over time.

• Nuclear Engineering and Technology
• /
• 제54권1호
• /
• pp.130-137
• /
• 2022

In the geological repository of radioactive nuclear waste, anaerobic corrosion can generate hydrogen, and may conservatively lead to the production of hydrogen-air layer. The accumulated hydrogen may cause a hazardous flame propagation resulting from any potential ignition sources. This study numerically investigates the processes of ignition and flame propagation in the layered mixture. Simple geometry was chosen to represent the geological repository, and reactive flow simulations were performed with different ignition power, energy, and locations. The simulation results revealed the effects of power and energy of ignition source, which were also analyzed theoretically. The mechanism of layered flame propagation was suggested, which includes three stages: propagation into the hydrogen area, downward propagation due to the product gas, and horizontal propagation along the top wall. To investigate the effect of the ignition source location, simulations with eight different positions were performed, and the boundary of hazardous ignition area was identified. The simulation results were also explained through scaling analysis. This study evaluates the potential risk of the accumulated hydrogen in geological repository, and illustrates the layered flame propagation in related ignition scenarios.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2022년도 추계학술대회
• /
• pp.162-163
• /
• 2022

Maritime transportation is going to transfer to alternative fuels as a result of the worldwide demands toward decarbonization and tougher maritime emissions regulations. Methanol is considered as a potential marine fuel, which has the ability to reduce SOx and CO₂ emissions, reduce climate change effects, and achieve the objective of green shipping. This work proposes and combines the innovative combination system of direct methanol solid oxide fuel cells (SOFC), proton exchange membrane fuel cells (PEMFC), gas turbines (GT), and organic Rankine cycles (ORC) for maritime vessels. The system's primary power source is the SOFC, while the GT and PEMFC use the waste heat from the SOFC to generate useful power and improve the system's ability to use waste heat. Each component's thermodynamics model and the combined system's model are established and examined. The multigeneration system's energy and exergy efficiency are 76.2% and 30.3%, respectively. When compared to a SOFC stand-alone system, the energy efficiency of the GT and PEMFC system is increased by 19.2%. The use of PEMFC linked SOFC has significant efficiency when a ship is being started or maneuvered and a quick response from the power and propulsion plant is required.

• 한국유체기계학회 논문집
• /
• 제12권1호
• /
• pp.43-50
• /
• 2009

Waste heat recovery process designs and performance analyses are conducted on the IGCC(Integrated Gasification Combined Cycle) power plants integrated with two different coal gasification and gas cleanup processes by Shell and GE/Texaco. Through the analysis results, the present study provides the steam integration concept between the HRSG and the chemical processes of IGCC power plant, and investigates the effect of steam integration on the power generation of IGCC power plant. The present simulation results show less steam power output and higher overall IGCC efficiency of the Shell-based power plant than the GE/Texaco.

• 환경영향평가
• /
• 제12권3호
• /
• pp.161-170
• /
• 2003

To investigate the characteristics of 17 solid waste landfills in the upper drainage basin of Lake Daechong, the landfill sites were surveyed, the leachate of these landfills were analyzed, and the analysis results were assessed from standpoint of water contamination. Sanitary landfills which are now being operated are relatively well equipped with facilities such as leachate collection, daily soil cover and landfill gas treatment devices. But a few of open-dumping landfills were leaking leachate apparently and were supervised improperly and neglectfully by local governments. Some of sanitary landfills exceeded the COD permission criteria of leachate effluent, and some of open-dumping landfills exceeded SS, T-P, Pb, As, Fe, Mn permission criteria of leachate effluent. To improve the water quality of Lake Daechong which is utilized for supplying drinking water, agricultural water, and industrial water to the great part of Chungchong area, the adequate and prompt measures for preventing Daechong Lake water contamination from landfills leachate is necessary.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
• /
• pp.60-63
• /
• 2004

Sulfurization of rare-earth oxides R203 (R=Nd, Eu) using sulfurizing reagents, such as $H_2S$ and $SC_2$was examined for the sulfide magnetic separation of spent fuel. $EU_2O_3$was found to react with H$_3$S gas forming the mixture of $EU_2O_2S$ and EuS at 500 oC, while EuS was formed by $SC_2$ at 800 oC. In the case of the mixture of $R_2O_3$and $UO_2$, EuS and $ND_3S_4$ were formed as well as $EU_2O_2S$ and $Nd_2O_2S$ at 500oC in $H_2S$, though $UO_2$ remained unreacted.

• 대한기계학회논문집B
• /
• 제25권2호
• /
• pp.252-259
• /
• 2001

Computational study has been performed to observe the flow characteristics of combustion chamber for geometrical modification in municipal solid waste incinerator. A series of geometrical modification has been carried out as an attempt to reduce the size of recirculation zone, to obtain uniform flow field in the secondary combustion chamber and to improve the mixing of combustion gas. Two dimensional non-reacting turbulent flow has been studied as the first step to get such goals and the result of design optimization is presented. In addition, three dimensional non-reacting and reacting flow analyses were performed to verify the validity of two dimensional approach.