• Journal of the Korean Applied Science and Technology
• /
• v.28 no.3
• /
• pp.367-373
• /
• 2011

This research is a basic researching process for producing solid fuel that mixing paper sludge and Heat Transfer Medium Oil. Under the presence of Heat Transfer Medium Oil, paper sludge is heated and dried with home appliance microwave for comparing drying efficiency and energy efficiency of different types of drying method. As a result, Heat Transfer Medium Oil and paper mixing case of drying method, OMD, is the most efficient way to shorten the time for evaporating moisture in the paper sludge. In addition, heat transfer effect and density is increased with adding Heat Transfer Medium Oil by microwave. Future more, OMD's energy cost for evaporating whole moisture is 78% cheaper than MD. Also, OMD process shows the best energy efficiency with comparing other process. Evaporation rate of paper sludge evaporation process with microwave is 11.66% increased by adding Heat Transfer Medium Oil 150g. Preheating Heat Transfer Medium Oil or improving different ways injecting Heat Transfer Medium Oil is a good way to increase a rate of initiative moisture evaporation process.

• Journal of Hydrogen and New Energy
• /
• v.28 no.5
• /
• pp.584-599
• /
• 2017

Biodiesel is renewable, eco-friendly, clean burning diesel replacement that is consisted of short chain alkyl ester. Biodiesel is derived from the transesterification of vegetables oils or animal fats with alcohol. The process has some technical problems that must be resolved to reduce the high operation cost. Eco-friendly physical technologies by using microwave have successfully improved the transesterification for biodiesel production. This paper attempts to extensively review microwave-assisted technology for biodiesel production. Additionally, different types of catalyst for biodiesel production have been summarized. It is concluded that the microwave-assisted technique improves the reaction rate significantly in comparison with conventional methods. Therefore it can be a suitable method of reducing the reaction time and can also decreases the cost of biodiesel production.

• Journal of the Mineralogical Society of Korea
• /
• v.26 no.3
• /
• pp.139-150
• /
• 2013

In order to effectively leach Fe from pyrite, the application of microwave energy and ammonia solution has been conducted. Pyrite transforms into hematite and pyrrhotite when treated with microwave radiation for 60 minutes, and in this time the highest amount of Fe was leached by the ammonia solution. Up to 99% of the Fe was leached when the experimental conditions were: 325-400 mesh particle size for the pyrite and 60 min. was the microwave exposure time. The ammonia leaching conditions were 0.3 M sulfuric acid, 2.0 M ammonium sulfate and 0.1 M hydrogen peroxide concentration. The pyrite, hematite, and pyrrhotite were not detected using XRD analysis from the solid-residues treated by the ammonia solution except for quartz.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1995.11a
• /
• pp.88-93
• /
• 1995

연소 배가스에서 NOx 제거시 분자 분해를 위하여 Microwave Energy를 이용했다. 이는 전자파를 흡수하는 고체물질에 전자파를 조사할 때 내부로 부터 가열이 이루어지는 특성과 전파의 진동에 의한 분자내 쌍극자가 진동하는 현상을 이용하여 분자결합이 깨지는 현상을 응용한 것이다. 전자파흡수체로서 Calcined Char를 사용했으며, 표준가스로는 NO 574 ppm을 2$\ell$/min으로 통과시키면서 2450 MHz의 전자파를 조사했을 경우 95 % 이상 분해 제거가 가능했다. 보다 낮은 농도의 연소배가스에 대해서는 거의 완전한 제거가 가능하므로 대기환경오염방지에 일조할 것으로 기대된다.

• Journal of the Korean Chemical Society
• /
• v.49 no.4
• /
• pp.370-376
• /
• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2017.10a
• /
• pp.207-208
• /
• 2017

• Journal of the Korean Vacuum Society
• /
• v.10 no.4
• /
• pp.424-430
• /
• 2001

An electron Boltzmann equation is solved numerically to calculate the electron energy distribution functions in plasma discharge which is generated by radio-frequency (RF) and microwave frequency electric field. The maintenance field strengths are determined self-consistently by solving the homogeneous electron Boltzmann equation in the Lorentz approximation expressed by 2nd order differential equation and an additional particle balance equation expressed by integro-differential equation. By using this numerical code, the electron energy distribution functions in argon discharge are calculated in the range from RF to microwave frequency. The influence of frequency of the HF electric field on the electron energy distribution functions and ionization rate are investigated.

• Korean Chemical Engineering Research
• /
• v.43 no.6
• /
• pp.683-690
• /
• 2005

The microwave carbonization of rice chaff was performed, and their kinetics were compared to those of conventional thermal carbonization. Thermal carbonization was carried out at $300-600^{\circ}C$ for 30 minutes. The weight loss and C/H mole ratio remarkably increased as increase of temperature, while there was no carbonization by microwave dielectric heating in spite of increasing incident power and irradiation time. However, microwave carbonization was successfully performed by addition of 6 wt％ of thermal carbonized rice chaff, it's C/H mole ratio is larger than 3.0, as a catalytic initiator to uncarbonized rice chaff, and the kinetics was depended on the incident power and irradiation time, resulting in the coincide with thermal carbonization to the Arrhenius equation. The activation energy of microwave carbonization was quite low as compared to that of thermal carbonization, while the kinetic constant was large. This is due to the internal volumetric heating characteristics of carbonized rice chaff by microwave. The effect of ash, and C/H mole ratio and amount of carbonized rice chaff were investigated on microwave carbonization.

• Journal of Environmental Health Sciences
• /
• v.22 no.3
• /
• pp.116-122
• /
• 1996

This study has been focused on the applicability of microwave treatment of soil contaminated by volitile organic chemicals. Substrates studied were sand and sandy soil. These substrates were impregnated with toluene, tetrachloroethylene, o-xylene and p-dichlorobenzene. The microwave treatment was conducted in a modified domestic microwave oven: 2450 MHz, 700 W. The sandy soil temperature added water went up rapidly to about 130$\circ$C for 4 minutes. And then, the temperature appeared to plateau out. A series of tests were performed to depict the effectiveness of microwave treatment technique to organic contaminants from soils. Removal efficiencies in sandy soil and sand were increased with increasing water content and exposure time. Microwave radiation penetrates the soil and heats water throughout the matrix. Therefore, addition of a certain amount of water to the contaminated soil can efficiently enhance the ability of the soil to absorb microwave energy and promote the evaporation of the volitile contaminants. And the vapour pressure of impregnated organic contaminants becomes lower. the removal efficiency becomes poor.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.5 no.2
• /
• pp.135-141
• /
• 1995

Abstract The sintering behavior and the electrical properties of sintered PZT ceramics using 2.45 GHz microwave energy were investigated. The ceramics were sintered between $1050 ~ 1130^{\circ}C$ for 5 min. Sintered body with high density and good electrical properties were achieved as the sintering temperature increases. Above $1090^{\circ}C$, however, the bulk density was decreased due to the volatilization of PbO component, and also electrical properties were decreased. The relative dielectric constant, mechanical Quality factor, electro- mechanical coupling factor of microwave sintered body at $1090^{\circ}C$ without PbO atmosphere were 1900, 80, 0.53 respectively, which were comparable to conventional sintering values. The sintering process completed within 20 min using microwave hybrid energy. The processing time and the amount of energy con-sumption could be reduced by microwave hybrid energy assisted rapid sintering.