• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.15-19
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• 2012

Wood wastes could be renewable resources by recycling as particleboard manufacturing or energy production. Particle board is the most common item of wood waste recycling and energy production from wood wastes has highlighted for energy recovery to reduce greenhouse gas generation in recent years. The aim of this study was to evaluate the environmental benefits of the processes for particle board manufacturing and energy production. The functional unit was one ton of wood wastes and the environmental impact was analyzed by life cycle assessment methodology. The result was that 112kg of carbon dioxide equivalent was produced from particle board manufacturing process and 382kg of carbon dioxide equivalent was produced from combined heat and power generation process. The concept of temporary biomass carbon storage was to applied to this study.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.546-548
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• 2003

The expanded waste glass material is one of the recycling materials. We investigated whether the expanded waste glass material is useful as planting basis and effective as heat insulation. We examined the difference of the materials by using vegetation index and temperature. The combination of the improved soils and the improved glasses marked higher vegetation index than other mixture materials. Moreover, this combination material is excellent than other ones to heat insulation. Therefore, it suggests that the expanded waste glass material has high potential to be used as a material for planting basis.

• Resources Recycling
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• v.33 no.4
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• pp.22-28
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• 2024

Waste PCBs contain a large amount of valuable resources, including copper, and technology to recover them is constantly being developed. Generally, to recycle waste PCBs, a physical pretreatment process such as shredding and crushing is required. However, during this stage, the loss rate of metals is high and the sorting efficiency is low, indicating a need for a more efficient recycling pretreatment process. In this study, a high-temperature milling process, which simultaneously employs heat treatment and ball milling, was utilized to efficiently recover copper from waste PCBs. An experiment was conducted at 350 ℃ with milling time, milling speed, and the weight of the balls as variables. The results showed a copper recovery rate of over 90% under the conditions of a ball weight of 500 g, a milling speed of 70 RPM, and a milling time of 5 hours. The purity of the recovered copper was approximately 93%, and through post-processing after the high-temperature milling process, the feasibility of reusing the recovered copper as a high-purity material was confirmed.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.85-90
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• 2006

The purpose of this research is to design an imitation boiler similar to the waste heat boiler installed on a plasma melting furnace in order to acquire a capability of a thermal design as to the circulation of heat and the discharge of noxious gas inside a boiler and to improve the efficiency of a waste heat boiler using the CFD (Computation Fluid Dynamics) program. The position of corrosion and the generation of a clinker inside a boiler due to temperature changes, combustion gas flows, and corrosive gases inside a boiler are examined to design the structure of an efficient boiler and recycle energy. As a result of this research, the boiler installed on a plasma melting furnace met the conditions of design by cooling the combustion gases discharged after the second combustion from an exhaust port, originally at 1,200 degrees Celsius, down to around 450 degrees Celsius. On the other hand, the circulation of corrosive gases (SOx and HCL) may lead to the generation of corrosion or a clinker in the upper and lower parts of an exhaust port more easily than any other parts of a boiler. Accordingly, the corrosion on the inside and outside walls of a boiler may result in a shortened lifespan of a boiler and an inability to recycle waste heat in an efficient manner. A prevention against corrosion at high and low temperatures needs to be considered in detail.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.47-48
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• 2023

In the domestic industrial sector, greenhouse gases emitted from the cement industry account for about 10%, with most of them generated during the cement clinker calcination process. During the calcination process, 57% of carbon dioxide is emitted from the decarbonation reaction of limestone, 30% from fuel consumption, and 13% from electricity usage. In response to these issues, the cement industry is making efforts to reduce carbon dioxide emissions by developing technologies for raw material substitution and conversion, improving process efficiency by utilizing low-carbon alternative heat sources, developing CO₂ capture and utilization technologies, and recycling waste materials. In addition, due to the limitations in purchasing and storing industrial byproducts generated from industrial facilities, many studies are underway regarding the recycling of construction waste. Therefore, this study analyzes the manufacture of calcium silicate cement (CSC), which can store carbon dioxide as carbonate minerals in industrial facilities, and aims to contribute to the development of environmentally friendly regenerated cement using construction waste.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.49-50
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• 2014

Dredged sea soil contains various contaminants. First priority to recycle dredged sea soil is to pretreat it to remove various contaminants because recycling dredge sea soil without any pre-treatment may cause a secondary contamination due to the leaching of hazardous chemicals. In this study, pretreated dredged sea soil was used to investigate pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined to evaluate pozzolanic activity. According to the results, pretreated dredged sea soil has some possibility to work as a pozzolanic material. When dredged sea soil was heat treated for 90min at 550℃, compressive strength was shown to be comparable to that of plain cement mortar.

• Resources Recycling
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• v.9 no.6
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• pp.23-30
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• 2000

Since most of the waste plastics are incinerated and landfilled for the plastic treatment, the environmental friendly processes must be introduced. The plastic utilization of plastic to the blast furnace as a substitutional fuel was developed as a useful recycling method of waste plastics, and commercialized in several ironmaking company in Europe and Japan. Present study was carried out to understand the effect of plastic injection on blast furnace process continuously by using the foundry blast furnace in POSCO. The coke replacement ratio turned out to be 0.98 with the waste plastic injection up to 13.8 kg/thm of injection rate, and there were no significant effect of the kinds of injection plastics on the replacement ratio in this test operation. The permeability in the furnace became worse and the heat load in the lower part of blast furnace was increased with increasing the injection rate of waste plastics. As the rate of plastic injection were increased, the top gas utilization and shaft efficiency were also decreased from the Rist diagram analysis.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.138-141
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• 2008

The 120t/d pyrolysis commercial plant for waste tire recycling have been constructed in Malaysia and is going to be operated. The plant have the tube reactor with chain conveyer attached disk developed in demonstration research stage. The reactor temperature for commercial plant is about 500deg.C and reactor inside pressure is -100$\sim$-120mmHg. Non-condensable gas is used as fuel for pyrolysis heat source, and the exhausted heat is recovered for cogeneration to produce steam and electric power of 600kw.

• Resources Recycling
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• v.31 no.5
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• pp.52-58
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• 2022

Silicon carbide powder was prepared from carbon black and silicon recovered from waste solar panels. In the solar power generation market, the number of crystalline silicon modules exceeds 90%. As the expiration date of a photovoltaic module arrives, the development of technology for recovering and utilizing silicon is very important from an environmental and economic point of view. In this study, silicon was recovered as silicon carbide from waste solar panels: 99.99% silicon powder was recovered through purification from a 95.74% purity waste silicon wafer. To examine the synthesis characteristics of SiC powder, purified 99.99% silicon powder and carbon powder were mixed and heat-treated (1,300, 1,400 and 1,500 ℃) in an Ar atmosphere. The characteristics of silicon and silicon carbide powders were analyzed using particle size distribution analyzer, XRD, SEM, ICP, FT-IR, and Raman analysis.

• Elastomers and Composites
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• v.54 no.1
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• pp.7-13
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• 2019

Recycling of waste polyvinyl chloride plastics has attracted much attention due to environmental problems, but the poor mechanical properties, low thermal stability, frequent breakage of strands, and melt cracking of the waste plastics have limited their widespread use. To overcome these disadvantages of waste PVC (W-PVC), recycled PVC powder blend was prepared by adding high-density polyethylene (HDPE) and ethylene vinyl acetate (EVA) as a heat stabilizer and compatibilizer, respectively. An intermeshing co-rotating twin screw extruder was used to prepare the blend, and the characteristics of the blend were analyzed by SEM and TGA, and by using a UTM and Izod impact tester. The impact strength was improved as the EVA content increased for the W-PVC/HDPE (80/20 wt%) blend. As the HDPE and EVA contents increased in the W-PVC/HDPE/EVA blend, the impact strength increased. SEM observations also revealed the improved interfacial adhesion for the EVA-containing blend.