• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.75-80
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• 2012

Gasification is a therm-chemical conversion process to convert various solid fuels into gaseous fuels under limited supply of oxygen in high temperature environment. Considering current availability of biomass resources in this country, the gasification is more attractive than any other technologies in that the process can accept various combustible solid fuels including plastic wastes. Mixed fuels of biomass and polyethylene pellets were used in gasification experiments in this study in order to assess their potential for synthesis gas production. The results showed that higher reaction temperatures were observed in mixed fuel compared to woodchip experiments. In addition, carbon monoxide, hydrogen, and methane concentrations were increased in the synthesis gas. Heating values of the synthesis gas were also higher than those from woodchip gasification. There are hundred thousand tons of agricultural plastic wastes generated in Korea every year. Co-gasification of biomass and agricultural plastic waste would provide affordable gaseous fuels in rural society.

• Resources Recycling
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• v.18 no.6
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• pp.54-59
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• 2009

The level manufacturing technique for refuse derived fuel (RDF) is possible to produce them itself by a domestic process which is appropriate in Korea. However, very few facilities were used for industrial combustible waste. The objective of this research is to develop the technique for refuse plastic fuel (RPF) of industrial waste. RPFs were prepared by mixing of plastic, paper and wood based on amount of regional waste. The physical properties of the RPFs prepared were investigated. RPFs prepared at mixing ratio(plastic : paper : wood) of 87.55% : 8.15% : 4.3% show the highest lower heating values in wet-base (LHVW) and the LHVW decreases as the mixing ratio of paper and wood increases.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.317-324
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• 2020

Plastic wastes generated from domestic waste are separated by mixed discharge with foreign substances, and the cost of the separation and screening process increases, so recycling is relatively low. In this study, as a fundamental study for recycling mixed plastic wastes generated from domestic waste into concrete aggregates, changes in concrete properties according to the plastic waste types and the substitution rate were evaluated experimentally. The mixed plastic waste aggregate(MPWA) was found to have a lower density and a higher absorption rate compared to the coarse aggregate with good particle size distribution. On the other hand, the single plastic waste aggregate(SPWA) was composed of particles of uniform size, and both the density and the absorption rate were lower than that of the fin e aggregate. It was found that the MPWA substitution concrete did not cause a material separation phenomenon due to a relatively good particle size distribution even with the largest amount of plastic waste substitution, and the amount of air flow increased little. The compressive strength and flexural strength of the PWA substitution concrete decreased as the amount of substitution of the PWA increased due to the low strength of the PWA, the suppression of the cement hydration reaction due to hydrophobicity, and the low adhesion between the PWA and the cement paste. It was found that the degree of deterioration in compressive strength and flexural strength of concrete substituted with MPWA having good particle size distribution was relatively small.

• Resources Recycling
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• v.23 no.4
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• pp.3-11
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• 2014

Large scale generation of plastic waste has generated considerable interest it seeking innovative solutions to waste recycling and reuse. Plastic solid waste(PSW) treatment and recycling processes could be allocated to four major categories, re-extrusion(primary), mechanical recycling(secondary), chemical recycling(tertiary) and energy recovery(quaternary). This review considers the various aspects of the PSW recycling such as recycling methods of PSW, special problems about some proposed process, separation techniques, and recycling of mixed PSW.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.92-97
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• 2022

Plastics are classified into 7 types such as PET (PETE), HDPE, PVC, LDPE, PP, PS, and Other for separation and recycling. Recently, large corporations advocating ESG management are replacing them with bioplastics. Incineration and landfill of disposal of plastic waste are responsible for air pollution and destruction of the ecosystem. Because it is not easy to accurately classify plastic materials with the naked eye, automated system-based screening studies using various sensor technologies and AI-based software technologies have been conducted. In this paper, NIR scanning devices considering the NIR wavelength characteristics that appear differently for each plastic material and a system that can identify the type of plastic by learning the NIR spectrum data collected through it. The accuracy of plastic material identification was evaluated through a decision tree-based SVM model for multiclass classification on NIR spectral datasets for 8 types of plastic samples including biodegradable plastic.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.28-36
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• 2006

The development of material separation technique for waste plastic recycling are the necessary situation restricted by law the reclamation and incineration of waste plastic after 2004, with enforcement of EPR (Extended Producer Responsibility) system. As the this study is the research on the development of electrostatic separation techniques for recycling of life circles waste plastic by development of charging material and charger, the separation efficiency can be improved. Therefore, we developed the charger and electrostatic separator to increase charging efficiency and material separation per object plastics, rising these equipments, we removed PVC up to $99\%$ from two kinds of mixed plastics. And in case of restricting PVC content such as PET, we developed the separation technique that can remove PVC up to $99.99\%$ from PET with PET recovery about $80\%$. Also, as we separated over $98\%$ for three kinds of mixed plastics, and then established material separation technique to increase recycling of plastic.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.23-33
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• 2005

The development of material separation technique for waste plastic recycling are the necessary situation according to restrict by law the reclamation and incineration of waste plastic after 2004 year, pith enforcement of EPR (Extended Producer Responsibility) system. As the this study is the research on the development of electrostatic separation techniques for recycling of life circles waste plastic, it can improve separation efficiency according to development of charging material and charger. Therefore, we developed the charger and electrostatic separator to increase charging efficiency and material separation per object plastics, using these equipments, we removed PVC up to 99% from two kinds of mixed plastics. And in case of restricting PVC content such as PET, we developed the separation technique that can remove PVC up to 99.99% from PET with PET recovery about 80%. Also, as we separated over 98% for three kinds of mixed plastics, and then established material separation technique to increase recycling of plastic.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.436-443
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• 2020

In this paper, we tried to examine the composition ratio of plastic waste from households according to the generated city and the qualities according to the production time of material recycling products. As a result, the composition ratio of recyclable plastic waste among the total plastic waste according to the generated cities is 64.5~90.4%, showing a big difference by city. In addition, the quality evaluation of material recycling products by production time for four months showed that the average tensile strength was 12.33MPa, the average elongation rate was 5.94%, the average density was 1.35g/㎤ and the average ash content was 3.66%.

• Resources Recycling
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• v.29 no.6
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• pp.88-97
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• 2020

In this study, the selected waste plastic waste logistics used for cement sintering were classified into two types through the process of sorting and crushing, analyzing the characteristics of each, and analyzing the correlation of the strength after cement manufacturing. The experimental variables were classified into soft and hard waste plastic waste, and the correlations between calorific value, chlorine, and moisture were analyzed. In addition, some of each waste was selected and melted, and the basic characteristics were evaluated by analyzing the structure and calorific value. The results of the experiment showed that it was evaluated that it is suitable to obtain a heat source by separating soft waste plastic wastes and sintering them with materials having similar properties. As a result of examining the wastes by strength after cement manufacturing, it was analyzed that the use of hard plastics greatly contributes to the compressive strength on the 1st and 28th, and the use of soft plastics contributes to the compressive strength on the 28th. However, these characteristics are evaluated by collecting only a part of the waste, and since the deviation of the waste occurs, continuous management is required, and a follow-up study on the environmental problems caused by the use of waste is required.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.167-168
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• 2020

In order to expand the material recycling of waste plastics made of composite materials, it is necessary to develop the use of material recycling products and to secure their quality stability. In this paper, as a basic study to secure the stability of the quality of household waste plastic material recycling products, the quality characteristics of recycled materials according to the production period were compared and reviewed. In addition, the average tensile strength of the recycled products by production period for 4 months was 12.33 MPa, and the average density was 1.35 g/m3.