• Title/Summary/Keyword: Energy Fuels

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A Study on Relationship between Fuel Characteristics and Combustion Characteristics of Reformed Diesel Fuels by Ultrasonic Energy Irradiation (II) - Relationship between Chemical Structure and Cetane Number - (초음파 개질 경유의 연료특성과 연소특성의 상관관계에 관한 연구 (II) -화학구조와 세탄가의 상관성-)

  • 이병오;류정인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.1
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    • pp.64-71
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    • 2003
  • In order to analyze the effect of the chemical structure and the cetane number of reformed diesel fuels by ultrasonic energy irradiation, proton nuclear magnetic resonance spectrometer$(^1H-NMR)$ was used. From the study, following conclusive remarks can be made. 1) Branch Index(BI), aromatics percentages, and alpha methyl radical$(H_{\alpha})$ of the reformed diesel fuels by ultrasonic energy irradiation decreased more than the conventional ones. 2) All the cetane numbers which were calculated from carbon type structure and hydrogen type distribution of the reformed diesel fuels increased more than the conventional ones. 3) It is more reasonable to predict cetane number equation from carbon type structure than from hydrogen type distribution. 4) BI, aromatics percentages, and $H_{\alpha}$ on both for conventional fuel and reformed diesel fuels by ultrasonic energy irradiation are inversely proportional to cetane number fur these fuels.

Stable In-reactor Performance of Centrifugally Atomized U-l0wt.%Mo Dispersion Fuel at Low Temperature

  • Kim, Ki-Hwan;Kwon, Hee-Jun;Park, Jong-Man;Lee, Yoon-Sang;Kim, Chang-Kyu
    • Nuclear Engineering and Technology
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    • v.33 no.4
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    • pp.365-374
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    • 2001
  • In order to examine the in-reactor performance of very-high-density dispersion fuels for high flux performance research reactors, U-l0wt.%Mo microplates containing centrifugally atomized powder were irradiated at low temperature. The U-l0wt.%Mo dispersion fuels show stable in- reactor irradiation behaviors even at high burn-up, similar to U$_3$Si$_2$ dispersion fuels. The atomized U-l0wt.%Mo fuel particles have a fine and a relatively uniform fission gas bubble size distribution. Moreover, only one of third of the area of the atomized fuel cross-sections at 70a1.% burn-up shows fission gas bubble-free zones, This appears to be the result of segregation into high Mo and low Mo.

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The developments of heavy hydrocarbon reformer for SOFC

  • Bae, Jung-Myeon
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.58.2-58.2
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    • 2012
  • Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

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Performance and Emission Characteristics of Ethanol and Methanol Gasoline Blended Fuels in a Spark Ignition Engine (스파크 점화기관에서 가솔린 에탄올과 메탄올 혼합 연료의 성능과 배기 특성)

  • HAN, SUNG BIN;PARK, JUN YOUNG
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.4
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    • pp.441-446
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    • 2016
  • Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and methanol gasoline blended fuels in a spark ignition engine. This experimental results showed that alcohol gasoline blended fuels decreased the torque, brake mean effective pressure, and brake power decreased when alcohol blended fuels were applied to a gasoline engine and also CO, HC and NOx emissions were reduced in accordance with the contents of alcohol contents.

DEVELOPMENT OF HOT CELL FACILITIES FOR DEMONSTRATION OF ACP

  • You, Gil-Sung;Choung, Won-Myung;Ku, Jeong-Hoe;Cho, Il-Je;Kook, Dong-Hak;Park, Seong-Won
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.02a
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    • pp.191-204
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    • 2004
  • The research and development of effective management technologies of the spent fuels discharged from power reactors are an important and essential task of KAERI. In resent several years KAERI has focused on a project named "development and demonstration of the Advanced spent fuel Conditioning Process (ACP) in a laboratory scale." The Facility for ACP demonstration consists of two Hot Cells and auxiliary facilities. It is now in the final design stage and will be constructed in 2004. After construction of the facility the ACP equipments will be installed in Hot Cells. The ACP will be demonstrated by some simulated spent fuels first and then by spent fuels.

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Solar Energy Development in Viet Nam: Opportunities and Challenges

  • Nguyen, Binh H.;Kim, Kyung Nam
    • Bulletin of the Korea Photovoltaic Society
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    • v.3 no.2
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    • pp.48-54
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    • 2017
  • Nowadays Viet Nam's energy supply which is mainly produced by fossil fuels energy such as coal, gas, and oil. However, the operation of fossil fuel power plants is one of the major causes of environmental pollution and climate change as well. It has a serious impact on the survival of human beings in general. As can be seen, the manufacturing industry is strongly invested, the demand for energy is also increasing. As traditional fossil fuels are being depleted and to minimize environmental pollution, renewable energy is the solution widely used by many countries in the world. Therefore, renewable energy has a significant role in maintaining the sustainability of world economy. Renewable energy sources such as solar energy, wind energy, biomass energy, geothermal energy can supply clean and nature-sourced energy to replace fossil fuels. Encouraging development of renewables is a general trend in the world today, which is also a common goal of COP21 commitment on global GHG reduction. The objective of this study is to assess the opportunities and challenges for renewable energy development in Vietnam, particularly for solar power. This study also discusses policies to promote the development of solar energy in Vietnam. While solar power provides ecological, economic and social benefits, it is exploited very modestly in Vietnam, where there are many barriers to slow down the development of renewable energy.

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DEVELOPMENT OF A COMPUTER PROGRAM FOR AN ANALYSIS OF THE LOGISTICS AND TRANSPORTATION COSTS OF THE PWR SPENT FUELS IN KOREA

  • Cha, Jeong-Hun;Choi, Heui-Joo;Lee, Jong-Youl;Choi, Jong-Won
    • Journal of Radiation Protection and Research
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    • v.34 no.1
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    • pp.1-7
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    • 2009
  • It is expected that a substantial amount of spent fuels will be transported from the four nuclear power plant (NPP) sites in Korea to a hypothetical centralized interim storage facility or a final repository in the near future. The cost for the transportation is proportional to the amount of spent fuels. In this paper, a cost estimation program is developed based on the conceptual design of a transportation system and a logistics analysis. Using the developed computer program, named as CASK, the minimum capacity of a centralized interim storage facility (CISF) and the transportation cost for PWR spent fuels are calculated. The PWR spent fuels are transported from 4 NPP sites to a final repository (FR) via the CISF. Since NPP sites and the CISF are located along the coast, a sea-transportation is considered and a road-transportation is considered between the CISF and the FR. The result shows that the minimum capacity of the interim storage facility is 15,000 MTU.

Bioenergy Crop Production and Research Trends (바이오에너지 원료작물 생산 및 연구동향)

  • Kim, Kwang-Soo;Kim, Young-Bum;Jang, Young-Seok;Bang, Jin-Ki
    • Journal of Plant Biotechnology
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    • v.34 no.2
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    • pp.103-109
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    • 2007
  • The increasing industrialization of the world has led to precipitous rise for the demand of petroleum-based fuels. The world is presently confronted with the twin crises of fossil fuel depletion and environmental pollution. The search for alternative fuels, which promise a harmonious correlation with sustainable development, energy conservation, efficiency and environmental preservation, has become highly pronounced in the present. Bioenergy is playing an increasingly important role as an alternative and renewable source of energy. Use of Bioenergy has several potential environmental advantages. The most important perhaps is reduction in life cycle greenhouse gases emissions relatives petroleum fuels, since bioenergy is derived from plants which convert Carbon dioxide ($CO_{2}$) into Carbohydrates in their growth. Bioenergy includes solid biomass, biomas and liquid bio-fuels which are fuels derived from crop plants, and include biomass that's directly burned. The two most important bio liquid fuels today are bioethanol from fermenting grain, grass, straw or wood, and biodiesel from plant seed oil.

Photocatalytic conversion of CO2 into hydrocarbon fuels with standard titania (Degussa P25) using newly installed experimental setup

  • Kim, Hye Rim;Razzaq, Abdul;Heo, Hyo Jung;In, Su-Il
    • Rapid Communication in Photoscience
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    • v.2 no.2
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    • pp.64-66
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    • 2013
  • Photoreduction of $CO_2$ into hydrocarbon fuels on the surface of photocatalyst is one of the breakthroughs in the field of photocatalysis. At present various approaches have been investigated with the aim of increasing the $CO_2$ conversion efficiency. The reactor for photoconversion of $CO_2$ plays a vital role in experimental setup. In this work an attempt was made to testify a newly designed the photoreactor for conversion of $CO_2$ into useful products. The photoreactor was specifically designed for simple operation bearing features of temperature and pressure control. The reactor has been tested successively with the standard titania, Degussa P25 yielding methane with moderate production rate of 30.8 $ppm{\cdot}g^{-1}{\cdot}h^{-1}$ under UV lamp with 365 nm wavelength. The methane yield obtained is comparable to the values reported in literature. Thus we anticipate that this experimental setup equipped with newly designed photoreactor can yield competitive amounts of fuels from $CO_2$ photoredcution via 365 nm UV light illumination on various photocatalysts.

Reduction Characteristics of Mass Produced Particle for Chemical-Looping Combustor with Different Fuels (매체순환식 가스연소기용 대량생산입자의 연료별 환원반응특성)

  • Ryu, Ho-Jung;Kim, Kyung-Su;Lee, Seung-Yong;Park, Yeong-Seong;Park, Moon-Hee
    • Transactions of the Korean hydrogen and new energy society
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    • v.19 no.4
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    • pp.348-358
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    • 2008
  • Reduction reactivity and carbon deposition characteristics of mass produced oxygen carrier particle(OCN-650) have been investigated by using hydrogen, methane, syngas, and natural gas as fuels. For all fuels, the maximum conversion and oxygen transfer capacity increased as the temperature increase. The reduction rate and the oxygen transfer rate increased as the temperature increase for methane. However, those values showed maximum at 900$^{\circ}C$ for hydrogen, syngas, and natural gas. To explain consistently the change of maximum conversion, reduction rate, oxygen transfer capacity, oxygen transfer rate and degree of carbon deposition for different fuels, new parameters such as reactive carbon contents and require oxygen per input gas were adopted.