• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.206.2-206.2
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• 2010

현재 RPF 생산공정에서 생산된 RPF는 약 7,500~8,500kcal/kg 의 높은 열량을 지니고 있다. 이러한 특성으로 연소시 소각로 내부의 온도가 부분적으로 급격히 상승하여 적정온도조절이 어렵고, 로내 장치들의 내구성이 저하되는 등 문제가 발생하고 있다. 또한, RPF에 포함된 비교적 높은 농도의 염소 함량(0.8~1.8% wt)으로 인해 다량의 대기오염물질이 발생되는 단점이 나타나고 있다. 따라서, 이러한 문제점들을 개선하기 위해 RPF의 개질이 필요하며 본 연구에서는 슬러지와 RPF를 혼합하여 열량, 성형성, 염소함량등을 고려하여 최적의 혼합비율을 선정하였다. J하수처리장에서 발생하는 하수슬러지를 이용하여 5, 15, 25, 30, 35%를 RPF 성형공정에 혼합하여 실험하였다. 5% 혼합시 발열량은 약 6,300~6,800kcal/kg, 염소농도는 0.8~1.6%(wt), 15% 혼합시 발열량은 5,500~6,000kcal/kg, 염소농도는 0.7~1.4%(wt), 25% 혼합시 발열량은 5,200~5,900kcal/kg, 염소농도는 0.6~1.1%(wt), 30% 혼합시 발열량은 5,000~5,700kcal/kg, 염소농도는 0.6~1.0%(wt), 35% 혼합시 발열량은 4,800~5,200kcal/kg, 염소농도는 0.4~0.6%(wt)으로 나타났다. 각 혼합비율에서 관찰된 성형성은 5~25% 혼합까지는 성형된 RPF와 유사하게 일정한 크기 및 강도를 유지 할 수 있었으나, 25% 이상 혼합시 분말형태의 가루가 많이 발생되며 강도가 약해져 쉽게 부스러지는 문제점등이 나타났다. 연료의 개질 형태나 성형성등을 고려하였을 때 슬러지 혼합비율이 약 15~25% 정도가 최적 혼합비율인 것으로 나타났다.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.186.1-186.1
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• 2011

Most of waste plastics including waste vinyls have been recycled up to about 50% of waste production, 4.5 million ton per year in 2009. To fundamentally increase the recycled amounts of waste plastics to waste production, the energy utilization of waste plastics is inevitable. But the contents of PVC included in waste plastics can limit the use as a RPF and make the air pollutants such as HCl and dioxin when it burns in the combustion system. Accordingly the source dechlorination by using heating method can be applied to make low contents of HCl as less than 0.6%. In this study the twin screw reactor using heat medium was used for the source dechlorination. As results of study, it was considered that this system is effective for the industrilal application.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.11
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• pp.636-641
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• 2015

Waste energy conversion to SRF (Solid Refuse Fuel) has the effects not alternative fossil fuel usage but also the reduction of greenhouse gas. But the direct burning of the SRF including a plastic waste generates air pollution problem like soot, dioxin, etc. so that an application of pyrolysis and gasification treatment should be needed. The purpose of this study is to supply a basic thermal data of the pyrolysis gasification characteristics in the plastic-rich SRF which are needed for developing the novel pyrolyser or gasifier. To do so, a bench-scale test rig was newly engineered, and then experiments were achieved for the production characteristics of gas, tar, and char. While SRF sample, gasification air ratio, holding time changed as 2 g, 0.691, 32 min respectively, the $H_2$ 1.36%, $CH_4$ 2.18%, CO 1.88%, $Cl_2$ 15.9 ppm, HCl 6.4 ppm were composed. Also light tar benzene $4.03g/m^3$, naphthalene $0.39g/m^3$, anthracene $0.11g/m^3$, pyrene $0.06g/m^3$, gravimetric tar $18g/m^3$, and char 0.29 g was formed.

• Resources Recycling
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• v.22 no.6
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• pp.3-11
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• 2013

This study was carried out to estimate greenhouse gas reduction potentials under treatment methods of combustible wastes excavated from closed landfill. The treatment methods of solid wastes were landfilling, incineration, and production of solid recovery fuel. The greenhouse gas reduction potentials were calculated using the default emission factor presented by IPCC G/L method of IPCC (Intergovernmental Panel on Climate Change). The composition of excavated waste represented that screened soil was the highest (65.96%), followed by vinyl/plastic (19.18%). This means its own component is similar to the other excavated waste from unsanitary landfill sites. Additionally, its bulk density was 0.74 $t/m^3$. In case of landfilling of excavated waste, greenhouse gas emission quantity was 60,542 $tCO_2$. In case of incineration of excavated waste, greenhouse gas emission quantity was 9,933 $tCO_2$. However, solid recovery fuel from excavated waste reduced 33,738 $tCO_2$ of the greenhouse gas emission quantity. Therefore, solid recovery fuel production is helpful to reduce of greenhouse gas emission.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.55-61
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• 2018

This study evaluated if the selected samples meets the Solid Refuse Fuel quality criteria in Korea. Biomass and plastic wastes generated in D City were mixed in diverse ratio. When the biomass content was about 40%, the moisture content was close to the SRF criteria and was measured to be 9.8%. The ash contents were analyzed up to 4.19%, and the lower calorific values based on Steuer, Dulong Equation and Bomb Calorimeter were at least 4,851, 4,181 and 3,847 kcal/kg, respectively. As a result of the elemental analysis, sulfur and chloride content were measured up to 0.05%. Those values satisfied the SRF criteria. Also, heavy metals(Hg, Cd, Pb, As) were analyzed to be below the SRF criteria. This makes it possible to use efficiently the wood byproducts abandoned in the woods, and the physical properties of wood being weak to moisture can be supplemented with plastics. Consequently, if plastic and biomass were well mixed and made into SRF, it would overcome the problem of shortening the life span of incineration facilities due to the high temperature of plastic wastes in the incinerator.

• Clean Technology
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• v.20 no.1
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• pp.80-87
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• 2014

Numerical study was investigated to obtain the database for developing a fast pyrolysis power boiler by waste fuel. The studies with various conditions were performed using ANSYS FLUENT. Also, the fuel properties was experimentally analyzed to utilize the input parameters for numerical analysis, that were proximate and ultimate analysis, reaction kinetics included pyrolysis and combustion. The results showed that temperature, combustion and exhausted gases was changed with heating value of fuel and feeding rate. Finally, the stable operating condition by analyzing results was proposed.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.3
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• pp.65-74
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• 2008

In this study, the composition and physico-chemical characteristics of municipal solid waste (MWS) which was treated in four different area were investigated. It is necessary to measure the characteristics of MSW to build a waste treatment and Refuse Derived Fuel (RDF) facility, the data-base and total managing of the landfill. It was found that the average density of solid wastes is in the range of $78.15-199.8kg/m^3$. This MSW was composed of 8.87% of food wastes, 38.8% of papers, 34.12% of plastics & vinyls, 7.16% of textiles, 0.96% of wood, 1.3% of rubber & leathers and others, respectively. Most of MSW are composed of food, paper and plastic waste and more than 94% was combustible waste. For three components, moisture is 17.38%, combustible component is 69.03% and ash is 6.24%. The chemical element has the high order of carbon, oxygen, hydrogen on the dry basis of wastes. And the low heating value of the MSW which is measured by calorimeter is calculated as 2973.8 kcal/kg and high heating value of the MSW is calculated as 5209.94 kcal/kg.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.686-691
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• 2015

A basic research for utilizing solid refuse fuel (SRF) based on changing SRF properties (RDF, RPF) and types (pellet, fluff) is demonstrated. Physicochemical characteristics of SRF and also changes in thermal decomposition depending on combustion time and emission gas (NOx, CO, HCl, etc) concentration were investigated for applications to waste energy sources. In conclusion, RPF is easy to pelletize, and has better combustion efficiency, higher LHV, higher thermal reduction, and short combustion time because it is composed of plastic wastes homogeneously. Also, fluff type samples have better combustion efficiency, and short combustion time because it has wider exposed surface area for combustion. It can also save energy consumption for pelletizing.

• Resources Recycling
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• v.24 no.5
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• pp.15-21
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• 2015

Waste plastic differs in its speed of combustion owing to its variety in composition as well as kinds of plastic. This study is aimed at examining the thermal weight analysis and determination of its kinetics in order to derive the design element in pyrolysis of RPF (Refused Plastic Fuel) as the plastic solid fuel. Based on the result of TGA (Thermogravimetric analysis), kinetic characteristics were analyzed by using Kissinger method which are the most common method for obtaining activation energy, and experimental conditions of TGA were set as follows: in a nitrogen atmosphere, gas flow rate of 20 ml/min, heating rate of $5{\sim}50^{\circ}C/min$, and maximum hottest temperature of $800^{\circ}C$. The method used for determining the property of waste plastic when thermally decomposed was thought feasible as the basic data in deciding the performance, design, and optimal operating condition of the reactor in the actual reactor.

• Clean Technology
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• v.27 no.1
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• pp.1-8
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• 2021

Due to the negative impacts of microplastics (MPs) on the ecosystem, the investigation of its occurrence and its treatment from sewage and wastewater treatment plants (WWTPs) have received a lot of attention in the recent years. Most MPs are precipitated and removed with the sludge during the treatment process. Proper sludge management is immensely necessary to avoid MP exposure in the environment. However, the domestic research on this aspect is limited. This study reviews appropriate sludge management approaches to decrease environmental MP exposure. This can be achieved through investigating sludge generation and treatment, regulation laws and government policy trends with an emphasis on WWTPs. The ratio of sludge in sewage treatment plants has been observed to be highest in recycling followed by incineration and landfills. Recycling is the highest in fuel followed by construction materials and composting. For WWTPs, the highest ratio is in recycling followed by fuel and landfills, and recycling is confirmed in the following order: incineration > after composting > after solidification > earthworm breeding. Treatment approaches that can increase the exposure of MPs to the ecosystem are considered to be used in landfills and agricultural fields. However, this method is not appropriate given the insufficient capacity of domestic landfills and the sufficient supply of existing chemical and animal manure fertilizers. Instead, it would be rational in terms of environmental preservation to expand the use of fuel and energy in connection with the new and renewable energy policy, and to actively seek the use of sub-materials for construction materials. In order to secure the basic data for the effectiveness of future planning and revision of related laws, it is required to perform an in-depth investigation of the sludge supply and demand status along with the environmental and economic effects.