• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.751-754
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• 2001

A possibility of using waste plastics as a source of secondary fuel in blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. for instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with the decrease of particle size, the combustibility of waste PE could be improved at a given distance from tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at longer distance from tuyere.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.755-758
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• 2001

Most of the waste plastics are incinerated and landfilled now, leading to much environmental problems. The technology of injection into the blast furnace was developed as a useful recycling method of waste plastics, and applied to the actual operation in several ironmaking companies. We carried out the test operation to inject continuously the two kinds of waste plastics through four tuyeres of the Foundry blast furnace in POSCO by 130 ton of total amount. From this test operation, we analyzed the coke replacement ratio, the permeability, the heat load and other changes of furnace conditions with the injection of waste plastics into the blast furnace. Some trials based upon the theoretical approaches were applied to examine the efficiencies of blast furnace.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.683-691
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• 2018

The plastic strategy adopted by the EU in January 2018 was established to implement circular economic policies and the Sustainable Development Goals(SDGs) of the United Nations. The strategy includes the vision and implementation measures to achieve, which are primarily measures to improve recycling and increase demand for recycled plastics. The representative measures include the design that considers recycling possibilities, reinforcement of demand for recycled plastics, suppression of occurrence, and response to micro-plastics. The policies to implement these measures include legislative restrictions and economic measures (EPR, GPP). It is especially desirable that the policies are applied differently depending on the plastic product. The Korean government has established comprehensive measures for all stages from production to recycling, but those measures are not comprehensive compared to the EU's strategy. The reason is that the refusal of waste collection makes the Korean government establish the approach from the aspect of waste management instead of the implementation of a circular economy or SDGs like the EU. The countermeasures are aimed at achieving a 50% reduction in waste generation amount and a 70% recycling rate. It is considered that the possibility of achieving the goal will increase by examining the measures and policy means in the EU's plastics strategy.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.117-124
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• 2006

The effects of binder content and recycling mixed waste plastics(PA) content on the workability, work life and hardening shrinkage of fresh polymer concrete using mixed waste plastics are examined. As a result, the workability of the polymer concretes using mixed waste plastics tend to improve with increasing binder content, PA content and filler content. The work life of the polymer concretes using mixed waste plastics is shortened with an increase in the initiator content and curing temperature. The length change of the polymer concretes using mixed waste plastics tend to increased with Increasing binder content and PA content. The result of the present research is expected to make a contribution to the recycling of final mixed waste plastics and the continuing efforts for the development of use of the recycled products are thought to expand the horizon for the recycling of the final mixed waste plastics.

• 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.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.201-206
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• 1992

Annual amount of plastics waste including rubber and leather waste, generated in 1990 was about 2,600,000 tons. Amount of generation of plastics waste has rapidly increased, but fractions of recycling and incineration have gradually decreased. Recently, two-stage incinerator, consisting of gasifier and gas combustor, draws much attention in Korea. Plastics are gasified in the starved air condition in the gasifier and produced gas is fired in the combustor. Combustion of produced gas is much easier than that of solid plastics, and produces a little pollutants. Standardzation of technology and process automation are still needed, but this incineration technology is in the commercial stage. Next topic concerned with this two-stage incineration will be how to treat complex plastics waste including toxic substances generated from automobiles and household appliances. Pyrolysis, realized by indirect heating in inert atmosphere, can provide high-quality products with minimum emissions. Many plastics are easily decomposed into oil in pyrolysis conditions, which can be utilized as chemical feedstocks, or gasoline or kerosene depending on feed materials and operating conditions. This has been demonstrated in several pilot-scale tests performed in Japan, Germany, etc. Easy removal of HCl from PVC is one of the most decisive merits of pyrolysis process. But in general, further efforts should be made for the process to obtain marketability. The future of pyrolysis process depends on public concern about environmental problems and oil prices.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.236-239
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• 2001

In this study, the compound materials of GRT/plastics (HDPE, LLDPE, LDPE, PP and PS) were developed. Their tensile strength, strain at yield and flexural modulus according to the change in CRT content were measured. And, the physical properties of the compound materials that the GRT content was changed in the waste vinyl HDPE and pure HDPE were measured, compared and analyzed. If tile GRT is added to PE plastics, the physical properties were superior to those of PP and PS, and in the case of HDPE, the waste vinyl HDPE had superior physical properties by the GRT content to the pure HDPE.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.219-226
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• 2006

The effects of binder content and PA content on the flexural, compressive and impact strengths, water absorption and frezzing and thawing of polymer concrete using mixed waste plastics are examined. As a result the flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics tend to increase with increasing binder content and filler content, regardless of the PA content. The flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics decrease with increasing PA content. The water absorption of the polymer concretes using mixed waste Plastics tend to decreased with increasing binder content, regardless of the PA content. The durability factor of the polymer concretes using mixed waste plastics tend to increased with increasing binder content. However, the durability factor of the polymer concretes using mixed waste plastics tend to decreased with increasing PA content.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.597-601
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• 2001

Waste plastics amount is more than 3.5 million tons and 30% of industrial waste in 1998, Korea but recycling rate of industrial waste plastics is quite low because the material separation technology from the mixed waste plastic powders is not commercially available so far. This study covers the triboelectrostatic separation of polyvinylchloride (PVC) materials collection chambers and controllers. PVC and PET powders can be imparted negative and positive surface charges, respectively, due to the difference of triboelectric charging series between particles and particles in the fluidized bed tribocharger, and can be separated by passing them through an external electric field. The extract content and yield of PVC separation from the mixed PVC and PET plastic powders are 90.0% and 98.2%, respectively. The electrostatic separation system using the fluidized bed tribocharger shows the potential to be an effective method for removing PVC materials from other mixed plastics.

• 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.