• 제목/요약/키워드: waste-to-energy

검색결과 2,688건 처리시간 0.041초

Development of advanced rigorous two-step code system for evaluation of radioactive waste with high-resolution activation calculation

  • Kim, Do Hyun;Kim, Jiseok;Lee, Han Rim;Sun, Gwang Min;Shin, Chang Ho;Kim, Jong Kyung
    • Nuclear Engineering and Technology
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    • 제53권6호
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    • pp.2011-2018
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    • 2021
  • Nowadays, evaluation of amounts and distributions of radioactive waste is an important preparatory step in the process of nuclear reactor decommissioning. For tentative estimation of radioactive waste, a cell-based rigorous 2 step (R2S) method usually is used; however, a poor resolution caused by the averaged flux and spectrum in a cell is still a great challenge because of leading to underestimated or overestimated results. To overcome the poor resolution, several systems were introduced. Neither system, however, provides any function for evaluation of radioactive waste amount and distribution. Thus, it is additionally required to classify radioactive waste based on the results of activation calculation. In this study, the advanced R2S (AR2S) system was developed. To verify the performance of the system, its results for a verification problem were compared with those of the cell-based R2S method. The results showed good agreement, which is to say, within 2.0% relative error. Also, several characteristics of fine/coarse mesh were analyzed. To demonstrate the performance of the AR2S system, the radioactive waste from the Japan Power Demonstration Reactor (JPDR) was estimated, and the result indicated a high-resolution distribution. Therefore, it is expected that the AR2S system will prove useful for precise evaluation of radioactive waste.

Behaviour of Uranyl Phosphate Containing Solid Waste During Thermal Treatment for the Purpose of Sentencing and Immobilisation: Preliminary Results

  • Foster, Richard Ian;Sung, Hyun-Hee;Kim, Kwang-Wook;Lee, Keunyoung
    • 방사성폐기물학회지
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    • 제18권3호
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    • pp.407-414
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    • 2020
  • Thermal decomposition of the uranyl phosphate mineral phase meta-ankoleite (KUO2PO4·3H2O) has been considered in relation to high temperature thermal sintering for the immobilisation of a uranyl phosphate containing waste. Meta-ankoleite thermal decomposition was studied across the temperature range 25 - 1200℃ under an inert N2 atmosphere at 1 atm. It is shown that the meta-ankoleite mineral phase undergoes a double de-hydration event at 56.90 and 125.85℃. Subsequently, synthetically produced pure meta-ankoleite remains stable until at least 1150℃ exhibiting no apparent phase changes. In contrast, when present in a mixed waste the meta-ankoleite phase is not identifiable after thermal treatment indicating incorporation within the bulk waste either as an amorphous phase and/or as uranium oxide. Visual inspection of the waste post thermal treatment showed evidence of self-sintering owing to the presence of glass former materials, namely, silica (SiO2) and antimony(V) oxide (Sb2O5). Therefore, incorporation of the uranium phase into the waste as part of waste sentencing and immobilisation via high temperature sintering for the purpose of long-term disposal is deemed feasible.

Overview of Coffee Waste and Utilization for Biomass Energy Production in Vietnam

  • Thriveni, Thenepalli;Kim, Minsuk;Whan, Ahn Ji
    • 에너지공학
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    • 제26권1호
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    • pp.76-83
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    • 2017
  • In this paper, the carbon resources recycling of the overview of coffee waste generation in Vietnam. Since few years, there has been a significant research studies was done in the areas of coffee waste generation areas and also waste water generation from coffee production. The coffee residue (solid) and waste water (liquid) both are caused the underground water contamination and also soil contamination. These residues contain high organic matter and acid content leads to the severe threat to environment. In second stage of coffee production process, the major solid residue was generated. Various solid residues such as spent coffee grounds, defective coffee beans and coffee husks) pose several environmental concerns and specific problems associated with each type of residue. Due to the unlimited usage of coffee, the waste generation is high. At the same time, some researchers have been investigated the spent coffee wastes are the valuable sources for various valuable compounds. Biodiesel or biomass productions from coffee waste residues are the best available utilization method for preventing the landfill problems of coffee waste residues.

유기성폐자원에너지 인센티브제도 도입방안 연구(III): 바이오가스화 인센티브제도(안) 마련 (A study on the introduction of organic waste-to-energy incentive system(III): Preparation of an incentive system for biogasification (proposal))

  • 문희성;권준화;이원석;이동진
    • 유기물자원화
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    • 제29권4호
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    • pp.87-97
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    • 2021
  • 본 연구는 폐자원에너지 활성화를 위한 폐자원에너지 인센티브제도(안)을 마련하기 위하여 수행되었다. 선행연구와 경제성 분석을 통해 에너지이용 형태별 가중치를 마련하였고, 폐자원에너지 인센티브(안)은 에너지이용 형태별로 에너지효율을 감안하여 산정되었다. 바이오가스화 시설 11개소의 경제성 분석 결과, B/C 수치가 0.16 ~ 1.69로 매우 다양하게 나타났다. 편익에서는 폐기물처리 반입료 수입이 전체의 68.4 ~ 99.3 %로 매우 높게 나타났고, 경영수지가 흑자(+)가 되는 '1' 이상인 시설이 4개소로 나타났다. 에너지 이용량을 판매량 Nm3 단위로 환산하기 위해 '단위환산' 계수로 발전 0.58 Nm3/KW, 스팀 0.17 Nm3/kg, 중질가스 1.00 Nm3/Nm3으로 산정하였고, '가중치'는 이용 형태별 각각 발전 0.249, 스팀 0.656, 중질가스 0.806으로 산정하였다.

열전발전 적용을 위한 가솔린차량의 전력 및 배기열 에너지 분석 연구 (Analysis of the Electric Energy and Exhaust Heat Energy for the Application of Thermo-Electric Generation in a Gasoline Vehicle)

  • 이영재;표영덕;김강출
    • 한국자동차공학회논문집
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    • 제10권1호
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    • pp.99-105
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    • 2002
  • About 70% of energy input to internal combustion engine is rejected to atmosphere by heat. By utilizing this waste heat, a plenty of energy can be conserved in nationwide. One of possible ways is the thermoelectric generation to utilize engine's waste heat to provide auxiliary electric power. Under th is concept, we have been developing the thermoelectric generation system to replace the alternator by converting the waste heat in the engine's exhaust directly to electricity This system may reduce the shaft horse power of the engine, then improves the vehicle fuel economy and the exhaust emissions. In the present study, the characteristics of the electric energy and exhaust heal energy in city and highway mode driving conditions are analysed by using a gasoline passenger car. These results would be used to determine the optimum design parameters of the thermoelectric generation system.