• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.675-679
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• 2001

The research is to discuss the current resource recycling and recovery policy, which was enacted by Environmental Protection Administrative (EPA) in Taiwan. For the past few years, the solid waste generated in Taiwan has greatly increased about 5 % per year. In addition to the construction of landfill sites and incineration plants, 4 R techniques (Reduction, Reuse, Recycle and Recovery) were also publicized among the citizens and then promulgated to furthermore manage these increased solid waste. Although the regulations have been carried out to a great success, they still need to be revised and updated since solid waste contains varieties of different materials. Therefore, this research discusses the current regulation and makes suggestion for future regulation revision. From the results of this study, energy recovery was suggested to be emphasized in the regulation. Energy could be recovered from materials such as waste tires, and all kinds of plastic containers. Waste tires and most of the plastic containers made of hydrocarbon species, which contains great heating values, should be considered as one of the alternatives for the resource recycling.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_2
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• pp.73-77
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• 2001

The disposal of sewage sludge using landfills and ocean dumping is no longer a viable option due to land scarcity and increasingly stringent environmental control regulations. As such, various efforts have been made to develop new sewage sludge recycling technologies. This work investigates the fundamental physical and chemical characteristics of rural type sewage sludge from Chungnam province in South Korea. The average moisture content, ignition loss, elementary analysis, and average heating value of the sewage sludge samples were examined. The average moisture content of the dewatered sludge was about 80%, while the organic matter was about 50% of the total solid sludge weight. The average heating value of a sewage sludge and petroleum coke waste mixture(1:1 weight ratio) was about 5,000 ㎉/kg, thereby indicating a high potential for energy recycling.

• Journal of the Korean Ceramic Society
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• v.44 no.2 s.297
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• pp.98-102
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• 2007

The stability of slurry and removal rate during recycling of colloidal silica slurry was evaluated in silicon wafer polishing. The particle size distribution, pH, and zeta potential were measured to investigate the stability of colloidal silica. Large particles appeared as recycling time increased while average size of slurry did not change. Large particles were identified by EDS(energy dispersive spectrometer) as foreign substances from pad or abraded silicon flakes during polishing. As the recycling time increased, pH of slurry decreased and removal rate of silicon reduced but zeta potential decreased inversely. Hence, it could be mentioned that decrease of removal rate is related to consumption of $OH^-$ ions during recycling. Attention should be given to the control of pH of slurry during polishing.

• Journal of Energy Engineering
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• v.20 no.3
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• pp.236-241
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• 2011

In this study, considering a degree of proliferation resistance and sustainability, development status of perspective recycling systems for spent nuclear fuels (SNF) is comprehensively reviewed on the basis of the urgent needs of sustainable management measures for high level radioactive wastes such as spent nuclear fuels (SNF).

• Journal of Energy Engineering
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• v.14 no.2 s.42
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• pp.159-166
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• 2005

In Korea, although the generation of waste plastic has been increasing, the rate of recycling is considerably low and moreover, there is no suitable method for the treatment of waste plastics. However, pyrolysis, which is appropriate for the treatment of highly polymerized compounds, such as plastics, has recently gained much interest. In this study, a property of the products from the pyrolysis of mixed waste plastics, with a possible practical use for the recycling oil produced, were assessed. First of all, in order to investigate the pyrolysis characteristic of waste plastics, TGA (Thermogravimetric analysis) and DCS (Differential Scanning Calorimetry) were performed on a number of different plastics, including PP, LDPE, HDPE, PET and PS, as well as others. According to the result, it appeared that PP was the most efficiently pyrolyzed by changing the temperature, followed by LDPE, HDPE, PET, PS and the other plastics, in that order. From the results, the optimum conditions f3r pyrolysis were set up, and the different waste plastics pyrolyzed. The recycling oil produced from the flammable gases generated during the pyrolysis was com-pared with fuel oil by an analysis using the petroleum quality inspection method on KS(Korea industrial Standard). The results of the analysis showed the recycling oil was of a similar standard to fuel oil, with the exception of the ignition point, with a quality somewhere between that of paraffin oil and diesel fuel. With respect to these results, the quality of the recycling oil produced by the pyrolysis of waste plastics was suf-ficient for use as fuel oil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.326-332
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• 2018

Korea faces major changes in energy policy, which include eco-friendly and zero-nuclear power. On the other hand, there are very few policies for the waste-management of mid- to large-sized lithium-ion batteries, such as electric car batteries and energy storage systems, which are expected to increase explosively due to such energy policy changes. Therefore, this study estimated the amount of mid- to large-sized lithium ion batteries waste and performed economics analysis of a middle and large sized secondary battery recycling project. Based on the results, a policy alternative for the revitalization of the related lithium-ion battery recycling industry is suggested. As a result, the B / C ratio of a domestic mid - to large - sized lithium ion battery recycling project is 1.06, in which the benefit is higher than the cost, so the business is economic feasible. Although the recycling project's economic efficiency is high, the recycling industry has not been activated in Korea because the domestic demand for rechargeable batteries recycling is very low. To solve this problem, this study proposes a plan to activate the industry by adding lithium secondary batteries to the EPR (Extended Producer Responsibility) items.

• 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.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.742-745
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• 2001

Plastics are one of difficult materials for recycling due to their characteristics in use. Recycling ratio of waste plastics was around 40% in last year in Japan, which includes energy recovery. Feed stock recycling and mechanical recycling are not easy because of additives in commercial plastics. Then, pyrolysis treatments have been done to recovery energy. Although plastics are easy to fire, complete combustion of them is not easy if anti-firing agents are added especially. Therefore, researches on pyrolysis or combustion behaviors of plastics containing additives are important from a view point recycling of plastics. Direct observation of popular plastics like polystyrene (PS), polycarbonate (PC), polyphenyle ether (PPE) and polyvinyl chloride (PVC) to investigate their pyrolysis behaviors in the present study. In case of PS, melting and gas evolution started at 9$0^{\circ}C$ and 39$0^{\circ}C$ respectively. And combustion finished at 445$^{\circ}C$. On the other hand, more than $600^{\circ}C$ and sufficient oxygen are required for complete combustion of PC and PPE.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.34-40
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• 2012

This research has looked into the treatment process of wood waste generated from industrial waste within the region and in order to modify the problem that may occurred during the mass balance were analyzed for development of suitable solid waste recycling network regionally. As as result, quite amount of wood waste are being transferred to another region, even though a treatment facility's capacity could bear the total amount of waste generated within the area. Although the wood waste could be treated locally, it is analyzed that amount of wood waste are being transferred due to inefficient and irrational processing system between regions. It is assumed that $CO_2$ generated and loss of unnecessary fuel cost from these inefficient system is quite a lot and in order to modify this disorganized system, it will not inevitable to treat the waste based on the characteristics of each regions. Also, the wood waste recycling system should be studied with the efficient, environmental friendly processing and delivering network by minimized transfer distance and local systemizing the waste treatment system.

• Resources Recycling
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• v.21 no.1
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• pp.66-74
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• 2012

In order to evaluate the feasibility of selective sulfidization of uranium and rare-earth(RE) oxides, an analysis on thermodynamic data, such as $M-O_2-S_2$ phase stability diagram and changes of Gibbs free energy for sulfidization of uranium and rare-earth oxides were carried out. Comparing $RE-O_2-S_2$ with $U-O_2-S_2$ phase stability diagram at wide range of sulfur potential, $UO_2$ remains unreacted, while RE oxides are sulfidized. The Gibbs free energy change(${\Delta}G^{\circ}$) of sulfidization of RE oxides is lower than that of uranium oxides. Thus, the selective formation of RE sulfides is possible during sulfidization of RE and uranium oxides at lower temperature. $CS_2$ was selected as a sulfidizing agent, because it is a stronger sulfidizing agent than other agents and reacts at lower temperature.