• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3745-3748
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• 2012

This study presents a rapid and simple ${\alpha}$ source preparation method for a radioactive waste sample. The recovery of $^{239}Pu$, $^{232}U$ and $^{243}Am$ using a micro-coprecipitation method was over 95%. The ${\alpha}$-peak resolution of Pu and Am isotopes through the micro-coprecipitation method is enough to discriminate the Pu and Am isotopes from other Pu and Am isotopes. The determination of the Pu and Am isotopes using the micro-coprecipitation method was applied to the radioactive waste sample, so that the activity concentrations of the Pu and Am isotopes using the micro-coprecipitation method in the radioactive waste sample were similar to those using the electrodeposition method.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.329-330
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• 2009

Food waste contains almost no heavy metals and high fuel ratio 0.14-0.17 that makes it a good candidate for solid fuel. Thermogravimetric analysis showed that volatile matter volatilizes at $200-400^{\circ}C$, and ignition temperature is $460^{\circ}C$. Combustion efficiency measured from energy balance before and after combustion was over 99%. Pulverized fuel made from food waste is a new and renewable energy which contribute to low carbon green economic growth.

• 방사성폐기물학회지
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• 제8권1호
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• pp.49-56
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• 2010

Pyroprocessing에 의한 사용후핵연료 처리 과정에서 방사성 희토류 염화물이 포함된 폐용융염이 발생된다. 이러한 폐 용융염 내에 존재하는 방사성 희토류 염화물을 산화물로 침전시켜 회수함으로서 용융염을 재생할 수 있다. 최종적으로 발생되는 방사성 희토류 산화물의 저장과 처분에 적합한 monolithic 고화체를 제조하기 위한 연구를 수행하였다. 본 연구에서는 고상 소결에 의해 붕규산 유리에 의한 고화체 제조, 희토류 산화물을 모나자이트로 합성한 후 붕규산 유리에 의한 고화체 제조를 수행하였다. 또한 zinc titanate 세라믹이 주요성분인 고화 매질(ZIT)을 개발하여 고화체를 제조하였으며 각각의 고화체에 대한 침출 및 물리화학적 특성을 비교 평가하였다. 고상 소결에 의해 제조된 ZIT 매질 고화체는 내 침출성이 크며 밀도가 크고 열전도도가 우수한 특성을 나타내었다.

• 설비공학논문집
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• 제29권2호
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• pp.57-62
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• 2017

The heat transfer performance of a multi-heat-source fluidized bed heat exchanger was analyzed. The fluidized bed heat exchanger examined in this study can simultaneously recover the waste heat from gas, water vapor, and hot water. The effects of waste water flow rate, gas flow rate, and cooling water flow rate were examined to find their experimental correlations with the heat transfer coefficient. A computer program using the correlations was developed in this study to predict the thermal performance of the fluidized bed heat exchanger. The calculated heat transfer rates of gas, water vapor, waste water, and cooling water were compared with the measured values. It was found that the error of the calculated values was less than 12%.

• 신재생에너지
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• 제10권4호
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• pp.36-46
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• 2014

Low-grade heats are wasted even though an amount of their energy is huge. In the small and medium industrial complex sites, large amount of low-grade thermal energy generated during the manufacturing process is wasted if it is not used directly for building heating or air-conditioning. In order to utilize this waste thermal energy more efficiently, organic Rankine cycle (ORC) was adopted. The range of operating temperature of ORC was set to $60^{\circ}C$ from $30^{\circ}C$ applicable low-temperature waste heat. A study was conducted to select an appropriate organic working fluid based on these operating conditions. More than 60 working fluids were screened. Eleven working fluids were selected based on the requirements as working fluid for ORC such as environmentally friendly, safety, and good operation on the expander. Finally, six working fluids were selected by considering the operating temperature ranges. Then, a cycle analysis was conducted with these six working fluids. As a results, R-245fa and R-134a appeared as appropriate working fluids for ORC operating at low-temperature condition based on the system efficiency and the turbine output power.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.80-89
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• 2002

A laboratory investigation of the behavior of radioactive metals under the various waste combustion atmospheres was conducted to predict the parameters that influence their partitioning behavior during waste incineration. Neodymium, samarium, cerium, gadolinium, cesium and cobalt were used as non-radioactive surrogate metals that are representative of uranium, plutonium, americium, curium, radioactive cesium, and radioactive cobalt, respectively. Except for cesium, all of the investigated surrogate metal compounds converted into each of their stable oxides at medium temperatures from 400 to 90$0^{\circ}C$, under oxygen- deficient and oxygen-sufficient atmospheres (0.001-atm and 0.21-atm $O_2$). At high temperatures above 1,40$0^{\circ}C$, cerium, neodymium and samarium in the form of their oxides started to vaporize but the vaporization rates were very slow up to 150$0^{\circ}C$ . Inorganic chlorine (NaCl) as well as organic chlorine (PVC) did not impact the volatility of investigated Nd$_2$O$_3$, CoO and Cs$_2$O. The results of laboratory investigations suggested that the combustion chamber operating parameters affecting the entrainment of particulate and filtration equipment operating parameters affecting particle collection efficiency be the governing parameters of alpha radionuclides partitioning during waste incineration.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.39-46
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• 2013

This work introduces a simple one-reactor adsorption desalination system that harnesses low temperature heat sources (solar energy, waste heat), which has been experimentally studied to elicit the most suitable design parameters and operating conditions. The design process of the system was divided into three parts to reflect the operating principle of desalination technology with application of adsorption processes. First, the evaporator for the vaporization of saline water was designed, then the reactor for the adsorption and release of the steam, followed by the condenser for condensation of the fresh water. The specific water yield is measured experimentally with respect to the time while controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. The present system well demonstrates the applicability of silica gel in relation to adsorption technologies that utilize low temperature heat sources ranging from 60 to $80^{\circ}C$, such as solar energy and waste heat.

• 신재생에너지
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• 제10권1호
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• pp.30-40
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• 2014

The main object of this study was to offer information about incoming waste in landfill and to evaluate biochemical methane and hydrogen sulfide potentials of landfill wastes. We examined brick, soil, mixed waste (C&D waste and MSW) samples for the study. The leaching experiments showed that BOD, COD and sulfate were determined in the range of 0~18,816 mg/kg, 85~21,100 mg/kg and 160~1,205 mg/kg, respectively in 6hr extraction test. An accumulated extraction tests for 140day were determined BOD 226~197,219 mg/kg, COD 436~242,588 mg/kg and Sulfate 1,090~25,140 mg/kg. Also, BMP (biochemical methane potential) tests were carried out to examine methane and hydrogen sulfide yields for the 3 different wastes. As a result, methane yield was determined to 262.68 mL $CH_4/g$ VS of MSW and 0~17.75 mL $CH_4/g$ VS in brick, soil and C&D waste. Higher hydrogen sulfide yield was observed to 0.079mL $H_2S/g$ VS in C&D waste. This result indicate that brick and soil could be sources of sulfate, and higher production of hydrogen sulfide could be odor problem and inhibitor of methane production.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.415-418
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• 2017

최근 폐열에너지와 스마트 그리드 연계를 통한 에너지 효율 향상 기술 수요가 증가하고 있는 추세이다. 또한 컨테이너 온실을 이용한 식물공장 개념의 스마트팜과 폐열 에너지의 실시간 활용을 위한 융합기술에 대한 연구를 통하여 고부가가치 작물을 재배에 대한 투자가 증가하고 있다. 이런 관점에서 에너지 효율 측면에서 LED 기반의 식물공장에 대한 경제성을 높여 농가에 실질적인 도움이 되는 실용화 기술에 대한 연구를 수행 하였다. 이는 향후 자동화될 대규모의 스마트 팜과 연계할 수 있는 기회를 제공할 수 있다. 본 연구에서는 폐열 에너지를 이용한 컨테이너 온실에서 냉방기술을 이용하여 작물재배의 경제성에 대한 연구이다. 컨테이너 온실, 폐열을 이용한 흡수식 냉동기를 IOT 기술을 이용하여 실시간 모니터링/제어하기 위하여 라즈베리 파이 기반의 게이트웨이를 모바일 기반에서 운영함으로써 냉방 에너지의 효용을 최대화 할 수 있는 새로운 형태의 농업 기술에 대한 연구를 제안하고자 한다.

• 신재생에너지
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• 제16권2호
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• pp.47-53
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• 2020

The amount of food waste and its water content depends on both the season and region. In particular, the water content typically varies between 73.8 wt.% and 83.3 wt.%, depending on the proportion of vegetables. Current food waste drying technologies are capable of reducing the water content to less than 10 wt.%, while increasing the heating value. Ongoing studies aim to utilize dried food waste as fuel. Food waste can be used to produce solid refuse fuel (SRF) by mixing it with various solid fuels or other types of waste. The analysis of specimens is very important when considering the direct combustion of food waste or its co-firing with solid fuels. In this study, the weight reduction of specimens after burning them in a small combustor, and compared with the results of thermogravimetric analysis (TGA). The concentration of various chemicals was also measured to define the characteristics of waste generation. Performed proximate analysis, elemental analysis, TGA, combustion experiment, the heating value, and derivative thermogravimetry (DTG).