• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.627-639
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• 1998

A combustion model for the incineration of municipal solid waste(MSW) in the stoker type incinerator was developed by considering the variation of physical composition of MSW. Theoretical analysis and numerical simulation for the combustion characteristics in incinerator were conducted by using the present model and the effects of compositional variation on the incineration characteristics of MSW was examined theoretically. It is found that large excess air enhances drying, but depresses volatilization. For the large value of moisture content, pyrolysis is fast but drying is slow. As the value of plastic content increases, devolatilization becomes slower. Larger amount of primary air supply to the rear side of stoker leads to increase the possibility of delaying the combustion.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.423-435
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• 2005

본 연구는 PVC를 포함한 혼합플라스틱을 연료화하는데 있어서 가장 큰 장애요인으로 되어있는 염소분을 효율적으로 제거하기 위한 목적으로 진행되었다. 염소성분을 원천적으로 제거하기 위해서는 PVC 내에 함유된 염소분을 제거하는 것이 관건이며 원천탈염을 통하여 제거하지 않으면 총괄 염소분의 변화가 없기 때문에 실제로 연료사용에는 한계가 있는 경우가 많다. 본 연구는 PVC중 56% 이상 함유되어 있는 염소성분을 연속식 스크루 반응기에 의하여 가열하여 제거하는 방식을 사용하였으며 각 공정의 변수별로 제거효율을 분석하여 최적조업조건에 대한 분석을 실시하였다. 일반적인 공정조업조건은 공급량, 혼합 플라스틱의 점도, 2차 반응기의 온도, 스크루 회전수 등이며 이 가운데 가장 결정적인 조건은 가열온도 변수이며 여타의 최적조업조건 하에서 $300^{\circ}C$ 이상인 경우에는 90% 이상의 탈염효율을 유지할 수 있음을 알 수 있었다.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.691-709
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• 2007

Concerns on environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer's demand for high quality food products has caused an increasing interest in developing biodegradable packaging materials using annually renewable natural biopolymers such as polysaccharides and proteins. However, inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low water resistance are causing a major limitation for their industrial use. By the way, recent advent of nanocomposite technology rekindled interests on the use of natural biopolymers in the food packaging application. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to their nanometer size dispersion. These improvements include increased mechanical strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Consequently, natural biopolymer-based nanocomposite packaging materials with bio-functional properties have huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of natural biopolymer-based nanocomposite films, and their potential use in food packaging applications are addressed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.115-127
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• 2014

Addition of fibers in cement or cement concrete may be of current interest, but this is not a new idea or concept. Fibers of any material and shape play an important role in improving the strength and deformation characteristics of the cement matrix in which they are incorporated. The new concept and technology reveal that the engineering advantages of adding fibers in concrete may improve the fracture toughness, fatigue resistance, impact resistance, flexural strength, compressive strength, thermal crack resistance, rebound loss, and so on. The magnitude of the improvement depends upon both the amount and the type of fibers used. In this paper, locally available waste fibers such as coir fibers, sisal fibers and polypropylene fibers have incorporated in concrete with varying percentages and l/d ratio and their effect on compressive, split, flexural, bond and impact resistance have been reported.

• Journal of Life Science
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• v.11 no.3
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• pp.273-278
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• 2001

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. Deni-trification bacterium. Paracoccus denitrificans(KCTC 2350) is employed to estimate the ability and the characteristics of denitrification. In the immobilized biological reactor system, the measurement of absolute amount of active strain in the reactor is comparatively difficult or impossible. In this study, strain immobilized denitrification reactor was designed with the unwoven texture wrapped peeped hole plastic tube to calculated the absolute amount of active strain by comparing the activity of the immobilized reactor adn the free cell reactor. The reactor system was continuous stirred tank reactor and the rate of substrate consumption was assumed to be Michaelis-Menten equation. As a result, we found that the amount of immobilized active strain was the half of the total active strain in the reactor and the time required to reach in the equilibrium state in the immobilized reactor system was shorter than that of the free cell reactor system.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.11a
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• pp.369-386
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• 2017

현재 3D프린터의 원료는 대부분 필라멘트를 사용하고 있는데 가격이 고가인 점과 제작 시간의 문제점으로 3D프린팅 하는데 많은 제약이 따르고 있다. 또한, 원료를 재생 및 재활용하는 3D프린터는 현재까지는 없다. 특히 대형 출력물은 많은 원료가 투입되어야 하기 때문에 제조단가가 상승하고, 그에 따른 3D프린터의 보급과 서비스 확장에도 한계가 있다. 본 연구에서는 현재 재활용되고 있는 플라스틱 소재를 재활용할 수 있는 3D프린터 시스템의 기술개발과 응용서비스를 분석하였다.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1560-1564
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• 2005

The influence of cetyltrimethylammonium bromide (CTAB) on the electrochemical behavior of bisphenol A at the carbon paste electrode (CPE) was investigated. CTAB, with a hydrophobic C-H chain, can adsorb at the CPE surface via hydrophobic interaction and then change the electrode/solution interface, and finally affects the electrochemical response of bisphenol A, confirming from the remarkable oxidation peak current enhancement. The electrode process of bisphenol A was examined, and then all the experimental parameters which affects the electrochemical response of bisphenol A, such as pH value of the supporting electrolyte, accumulation potential and time, potential scan rate and the concentration of CTAB, were examined. Finally, a sensitive and simple voltammetric method was developed for the determination of bisphenol A. Under the optimum conditions, the oxidation peak current of bisphenol A varied linearly with its concentration over the range from $2.5\;{\times}\;10^{-8}\;to\;1\;{\times}\;10^{-6}$ mol/L, and the detection limit was found to be $7.5\;{\times}\;10^{-9}$ mol/L. This method was successfully employed to determine bisphenol A in some waste plastic samples.

• New & Renewable Energy
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• v.5 no.4
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• pp.52-58
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• 2009

Upgrading of pyrolysis wax oil using HZSM-5 catalyst has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation was studied with a function of catalyst amount and reaction temperature. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The catalytic degradation using HZSM-5 catalyst shows the high conversion of pyrolysis wax oil to light hydrocarbons. The liquid product obtained shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Here, the experimental variable such as catalyst amount and reaction temperature was influenced on the product distribution.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.53-59
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• 2013

Since 1990s, the major recycling methods for mechanical recycling of FRP(Fiber Reinforced Plastics)boats has involved shredding and grinding of the scrap FRP in a new recycled product. But still it leads to secondary problem such as air pollution, unacceptable shredding noise level and few limited applications. This study is to propose a newly advanced method which is more efficient and environment friendly waste FRP regenerating system. As extracting FRP layer and making the recycled fiber for recycled-fiber reinforced concrete(RFRC) from waste FRP, the recycling process has some merits in a sense of the recycling energy and the environmental effects. In this study, for those tasks, spectro-chemical differentiation method and coloring water-soluble dye treatment makes the roving layer more distinguishable photophysically. Also that has remarkably reduced safety hazards and energy. Using the mechanical properties of polymers and composite, FRP with the orthotropic and laminated plastic structure has been easily separated in the new extracting system. Also the new method has introduced five kind of separating manuals for the some different compositions of FRP boats. The roving fiber of laminated glass-fiber layer is as good as the polyvinyl fiber which is cost-high commercial fiber to increasing strength of concrete products. The early study has shown the effectiveness of laminated glass-fiber layer which also is chemical-resistant due to the resin coating. These results imply that more efficient and environment friendly recycled glass fiber can be better applied to the fiber reinforced concrete(FRC) substitute and this study also has shown wide concrete applications with RFRC from the waste FRP boat.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.112-117
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• 2007

This study aims to develop an alternative energy like oil made from marine organic waste by marine products waste, spent fishing nets. There are already many commercial examples and case studies based on the petroleum industry-refuse plastic or refuse tire, however, it is rare that a research developing alternative energy from food waste and organic waste. Therefore, this study investigated the oil made from thermal decomposition under the high temperature and high pressure condition, and examined the possibility for commercial use by testing its own characteristics. A bio-oil from thermal decomposition at $250^{\circ}C$ and 40 atm was hard to remove impurities because of its high viscosity, showed lower caloric value than heavy oil, and generated various gases which were not appropriate for the use of fuel. It is noticeable that thermal decomposition was occurred at $250{\pm}5^{\circ}C$ using steam pressure, which much lower compared to the existing method of thermal decomposition, more than $500^{\circ}C$. Since the high viscosity of bio-oil, it is necessary a further study to use as liquid fuel.